Occurrence of high level methicillin resistance Staphylococcus aureus in patients from health facilities in Akwa Ibom State, Nigeria

Background:Methicillin resistant S. aureus(MRSA) has become a major public health predicament worldwide. This is owing to its involvement in the evolution of MDR strains and difficulty in therapeutic management of infected patients. This study was conducted to investigate the prevalence of methicillin resistance Staphylococcus aureusamong patients in two health facilities in Akwa Ibom State, Nigeria.Materials and Methods:Clinical isolates of patients from University of Uyo Teaching Hospital (UUTH), Uyo and General Hospital, Ikot Abasi (GHIA) were investigated based on the strategic location of the hospitals. The study design was a descriptive cross-sectional study. Three hundred clinical samples were collected from male and female in and out-patients of all ages and processed using standard bacteriological methods. Detection of Staphylococcus aureusand MRSAstrains were done according to standard protocols while antibiotic susceptibility testing of MRSAisolates was conducted using Kirby-Bauer disc diffusion method and interpreted following the CLSI 2021 guidelines. Results:The prevalence of MRSAstrains in this study was 42.9%. Majority of patients with MRSAwere from UUTH (44%) closely followed by patients from GHIA(40%). High antibiotics resistant rates of MRSAwere recorded for ampicillin (96.6%), ciprofloxacin (73.3%), erythromycin (63.3%) and cotrimoxazole (60%). Gentamicin and ceftriaxone sensitivity rates were 53.3% and 63.4%, respectively. Conclusion:Health facilities in the state should institute effective antimicrobial stewardship, intensify surveillance and screening of Staphylococcus aureusfor MRSAstrains to guard against dissemination of multidrug resistant strains in both hospital and community settings because of the clinical implications

Occurrence of high level methicillin resistance Staphylococcus aureusin patients from health facilities in Akwa Ibom State, Nigeria

Background:Methicillin resistant S. aureus(MRSA) has become a major public health predicament worldwide. This is owing to its involvement in the evolution of MDR strains and difficulty in therapeutic management of infected patients. This study was conducted to investigate the prevalence of methicillin resistance Staphylococcus aureusamong patients in two health facilities in Akwa Ibom State, Nigeria.Materials and Methods:Clinical isolates of patients from University of Uyo Teaching Hospital (UUTH), Uyo and General Hospital, Ikot Abasi (GHIA) were investigated based on the strategic location of the hospitals. The study design was a descriptive cross-sectional study. Three hundred clinical samples were collected from male and female in and out-patients of all ages and processed using standard bacteriological methods. Detection of Staphylococcus aureusand MRSAstrains were done according to standard protocols while antibiotic susceptibility testing of MRSAisolates was conducted using Kirby-Bauer disc diffusion method and interpreted following the CLSI 2021 guidelines. Results:The prevalence of MRSAstrains in this study was 42.9%. Majority of patients with MRSAwere from UUTH (44%) closely followed by patients from GHIA(40%). High antibiotics resistant rates of MRSAwere recorded for ampicillin (96.6%), ciprofloxacin (73.3%), erythromycin (63.3%) and cotrimoxazole (60%). Gentamicin and ceftriaxone sensitivity rates were 53.3% and 63.4%, respectively. Conclusion:Health facilities in the state should institute effective antimicrobial stewardship, intensify surveillance and screening of Staphylococcus aureusfor MRSAstrains to guard against dissemination of multidrug resistant strains in both hospital and community settings because of the clinical implications.

Cultivo versus metagenómica para la identificación bacteriana en pacientes con osteomielitis de pie diabético: una revisión sistemática / Culture and metagenomics as bacterial identification methods in patients with diabetic foot ulcers: a systematic review

BACKGROUND: Diabetic foot osteomyelitis (DFO) is a serious complication of infected ulcers in a diabetic patient. The identification of the infecting microorganisms is generally by culture, which causes a bias. Recently, metagenomics has been used for microbial identification. AIM: To systematically review the scientific literature related to DFO in the last 10 years to evaluate if culture and metagenomics are complementary. MATERIAL AND METHODS: To carry out the systematic review, PRISMA and Rayyan were used for the selection of studies, using three databases, using the keywords diabetes, osteomyelitis, culture and microbiome. Articles in English or Spanish were included, containing information related to bacterial identification in DFO. Characteristics of the technique, patients and frequency of bacterial appearance were collected. RESULTS: Twenty six articles were included, 19 used culture and 7 metagenomics. The patients were predominantly men (68%), with an average age of 61 years, 83% had type 2 diabetes and comorbidities, mainly vascular and neuropathy. The Families with the highest frequency of appearance using the culture technique were Enterobacteriaceae (29.3%) and Staphylococcaceae(28.3%) and with metagenomics Peptoniphilaceae (22.1%) and Staphylococcaceae (9.4%). Peptoniphilaceae were not identified in culture, although they were frequently identified by metagenomics. Methicillin- resistant Staphylococcus aureus, regularly identified by culture, was not identified using metagenomics. CONCLUSIONS: Comparing results, there is a certain complementarity between microbiological culture and sequencing to identify bacteria present in DFO.

A retrospective analysis of clinical characteristics and prognostic factors for 152 cases of Staphylococcus aureus bloodstream infection / 中华预防医学杂志

To understand the clinical characteristics of Staphylococcus aureus bloodstream infection and the main risk factors affecting clinical prognosis, providing a reference for clinical prevention and control of Staphylococcus aureus bloodstream infection. In this study, the clinical data of 152 patients with Staphylococcus aureus bloodstream infection admitted to Guangdong Provincial People's Hospital from January 2019 to December 2021 were retrospectively analyzed by reviewing the electronic medical record system, including underlying diseases, clinical characteristics, risk factors, and bacterial resistance. Statistical methods such as Chi-Squared Test and t Test were used to analyze the related risk factors that may affect the clinical characteristics and prognosis of patients with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection, then the variables with P<0.05 in univariate analysis were included in the multivariate logistic regression model to analyze the independent risk factors of poor prognosis. The results showed among 152 patients with Staphylococcus aureus bloodstream infection, 50 patients (32.89%) were infected with MRSA. In comparison, 102 patients (67.11%) were infected with methicillin-sensitive Staphylococcus aureus (MSSA). Except for rifampicin, the resistance rate of MRSA to commonly used antibiotics was all higher than that of MSSA, and the difference was statistically significant (Chi-square values were 8.272, 11.972, 4.998, 4.776, respectively;all P-values are less than 0.05). Strains resistant to vancomycin, linezolid, and quinupristin/dalfopristin were not found. In the MRSA group, indwelling catheter and drainage tube, carbapenems, and β-lactamase inhibitor treatment were significantly higher than the MSSA group. The difference was statistically significant (P<0.05). The incidence of poor prognosis of bloodstream infection in the MRSA group was higher than that in the MSSA group (34.00% vs 13.73%), and the difference was statistically significant (χ2=8.495, P<0.05). No independent risk factors associated with poor prognosis were found in the included patients with MRSA bloodstream infection.Multivariate Logistic regression model analysis showed that solid malignant tumors (OR=13.576, 95%CI: 3.352-54.977, P<0.05), mechanical ventilation (OR=7.468, 95%CI: 1.398-39.884, P<0.05) were the most important independent risk factors for poor prognosis in patients with Staphylococcus aureus bloodstream infection. In summary, the poor prognosis rate of MRSA bloodstream infection is higher than that of MSSA. The clinical evaluation of related risk factors should be strengthened, targeted prevention and control interventions should be taken to improve the prognosis of patients with Staphylococcus aureus bloodstream infection, and the use of antibiotics should be rational and standardized, to control bacterial infection and drug resistance effectively .

Preparation and properties of hydrogels loaded with phage endolysin Lys84 / 生物工程学报

This study investigated the application of poly(N-isopropylacrylamide)-based interpenetrating network temperature-sensitive hydrogels (notation: IPNT) as the delivery vehicle for phage endolysin Lys84 and the potential of drug-loaded hydrogels as antimicrobial materials. Interpenetrating network temperature-sensitive hydrogels were prepared by free radical polymerization of sodium alginate and N-isopropylacrylamide. Drug-loaded hydrogels (IPNT-Lys84) were obtained by dry soaking method with the endolysin Lys84 of Staphylococcus aureus phage. The physical properties of the hydrogels with and without drug loading were characterized by infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry. The swelling and deswelling of the hydrogels as well as the release of endolysin Lys84 were investigated. Moreover, the antibacterial properties of IPNT-Lys84 hydrogels at different temperatures and concentrations of the drug solution were studied. The results showed that IPNT-Lys84 hydrogel had uniform pores and a low critical solubility temperature (LCST) of 32 ℃. The equilibrium swelling of the hydrogel was 30 g/g, and the water loss rate was 88% upon deswelling. The release rate of endolysin reached more than 70% within 6 h at 37 ℃. The bactericidal rate of IPNT-Lys84 hydrogel was over 99.9%. The research results showed the feasibility of using IPNT to deliver the endolysin Lys84, and IPNT-Lys84 hydrogel might be an effective antimicrobial material against multi-drug resistant Staphylococcus aureus.

Surveillance of bacterial resistance in children aged 0-14 years from 2018 to 2022 / 中华儿科杂志

Objective: To understand the distribution and antimicrobial resistance of common bacteria from children aged 0-14 years from China Antimicrobial Resistance Surveillance System. Methods: Bacterial resistance data of 2 575 040 strains from children aged 0-14 years were extracted from the national bacterial resistance surveillance reports from October 2018 to September 2022 and resistance changes were further analyzed by comparing with all data in each year. Results: The total number of bacteria isolated from children in 2018-2022 ranged from 415 306-588 016 strains, accounted for 15.9% (514 193/3 234 372), 16.2% (572 107/3 528 471), 12.8% (415 306/3 249 123), 13.0% (485 418/3 743 027), and 12.2% (588 016/4 828 509), respectively. The proportions of gram-positive bacteria among children were 45.4% (233 456/514 193), 44.5% (254 869/572 107), 44.7% (185 756/415 306), 42.6% (206 903/485 418), and 41.7% (245 044/588 016), respectively. The top five isolates of gram-positive bacteria were Staphylococcus aureus (36.0%-38.8%), Streptococcus pneumoniae (27.1%-31.7%), Staphylococcus epidermidis (7.3%-9.3%), Enterococcus faecium (4.0%-4.8%), and Enterococcus faecium (2.5%-3.6%), and the top five isolates of gram-negative bacteria were Escherichia coli (21.8%-26.2%), Haemophilus influenzae (14.4%-26.4%), Klebsiella pneumoniae (10.1%-14.7%), Moraxella catarrhalis (7.3%-11.9%), and Pseudomonas aeruginosa (5.5%-6.8%). The bacteria from children aged 0-14 years commonly isolated from sputum samples (48.8%-57.0%). The prevalence of methicillin-resistant S. aureus was 28.7%-30.1%. The detection rates of vancomycin-resistant E. faecalis or E. faecium were 0.1%-0.3%. The proportions of non-cerebrospinal fluid-derived penicillin-resistant S. pneumoniae were 0.7%-1.6%. The prevalence of cefotaxime and (or) ceftriaxone-resistant E. coli and K. pneumoniae decreased were 43.7%-50.0% and 31.8%-42.7%, respectively. The resistant rates of E. coli to imipenem and meropenem were 1.2%-1.9% and 1.2%-2.0%, respectively, and the resistant rates of K. pneumoniae to imipenem and meropenem were 7.3%-10.1% and 8.2%-12.2%, respectively. About 6.6%-10.2% and 5.3%-9.6% of the P. aeruginosa isolates showed resistant to imipenem and meropenem, respectively, while 17.2%-24.0% and 19.0%-29.4% of the Acinetobacter baumannii isolates were resistant to imipenem and meropenem, respectively. Conclusions: There is no significant change in the composition of common clinical pathogens in children aged 0-14 years from 2018 to 2022. The prevalence of some resistant bacteria such as methicillin-resistant S. aureus and carbapenem-resistant Enterobacterales is decreasing. However, it is necessary to pay attention to antimicrobial resistance of bacteria from children and long-term monitoring of the prevalence of resistant bacteria should be conducted.

Clinical and etiological characteristics of infectious vulvovaginitis in children in Zhejiang province from 2009 to 2019 / 中华儿科杂志

Objective: To explore the clinical characteristics, common pathogens in children with vulvovaginitis. Methods: This was a retrospective cases study. A total of 3 268 children with vulvovaginitis were enrolled, who visited the Department of Pediatric and Adolescent Gynecology, Children's Hospital, Zhejiang University School of Medicine from January 2009 to December 2019. Patients were divided into 3 groups according to the age of <7, 7-<10 and 10-18 years. Patients were also divided in to 4 groups according to the season of first visit. The pathogen distribution characteristics of infective vulvovaginitis were compared between the groups. Their clinical data were collected and then analyzed by χ2 test. Results: The were 3 268 girls aged (6.2±2.5) years. There were 1 728 cases (52.9%) aged <7 years, 875 cases (26.8%) aged 7-<10 years, and 665 cases (20.3%) aged 10-18 years. Of these cases, 2 253 cases (68.9%) were bacterial vulvovaginitis, 715 cases (21.9%) were fungal vulvovaginitis and 300 cases (9.2%) were vulvovaginitis infected with other pathogens. Bacterial culture of vaginal secretions was performed in 2 287 cases, and 2 287 strains (70.0%) of pathogens were detected, of which the top 5 pathogens were Streptococcus pyogenes (745 strains, 32.6%), Haemophilus influenzae (717 strains, 31.4%), Escherichia coli (292 strains, 12.8%), Staphylococcus aureus (222 strains, 9.7%) and Klebsiella pneumoniae (67 strains, 2.9%). Regarding different age groups, H.influenzae was the most common in children under 7 years of age (40.3%, 509/1 263), S.pyogenes (41.9%, 356/849) was predominantly in children aged 7 to 10 years, and E.coli was predominant in children aged 10 to 18 years (26.3%, 46/175). Susceptibility results showed that S.pyogenes was susceptible to penicillin G (610/610, 100.0%), ceftriaxone (525/525, 100.0%), and vancomycin (610/610, 100.0%); the resistance rates to erythromycin and clindamycin were 91.9% (501/545)and 90.7% (495/546), respectively. For H.influenzae, 32.5% (161/496) produced β-elactamase, and all strains were sensitive to meropenem (489/489, 100.0%) and levofloxacin (388/388, 100.0%), while 40.5% (202/499) were resistant to ampicillin. Among E.coli, all strains were sensitive to imipenem(100%, 175/175). The resistance rates of E.coli to levofloxacin and ceftriaxone were 29.1% (43/148) and 35.1% (59/168), respectively. A total of 48 strains of methicillin-resistant Staphylococcus aureus (MRSA) were isolated with a proportion of 28.3% (45/159) in 3 268 patients. The results of drug susceptibility test showed that all MRSA strains were sensitive to linezolid 100.0% (40/40), vancomycin (45/45, 100.0%), and tigecycline (36/36, 100.0%); the resistance rates of MRSA to penicillin G, erythromycin and clindamycin were 100% (45/45), 95.6% (43/45) and 88.9% (40/45), respectively. All methicillin-sensitive Staphylococcus aureus (MSSA) strains were sensitive to oxacillin (114/114, 100.0%), linezolid (94/94, 100.0%), vancomycin (114/114, 100.0%), and tigecycline (84/84, 100.0%); it's resistance rates to penicillin G, erythromycin and clindamycin were 78.1% (89/114), 59.7% (68/114) and 46.5% (53/114), respectively. The drug resistance rate of MSSA to penicillin G, erythromycin and clindamycin were lower than those of MRSA (χ²=11.71,19.74,23.95, respectively, all P<0.001). Conclusions: The age of consultation for pediatric infectious vulvovaginitis is mainly around 6 years. The most common pathogens are S.pyogenes, H.influenzae and Escherichia coli. Third generation cephalosporins can be used as the first choice of empirical anti-infection drugs. However, the results of drug susceptibility should be considered for targeted treatment.

Antimicrobial and toxicological evaluation of Origanum vulgare: an in vivo study / Avaliação antimicrobiana e toxicológica de Origanum vulgare: um estudo in vivo

Origanum vulgare has been of great interest in academia and pharma industry due to its antioxidant, antifungal and antitumor properties. The present study aimed to find the anti-MRSA potential and in vivo toxicity assessments of O. vulgare. O. vulgare extract was used to monitor anti-MRSA activity in mice. Following MRSA established infection in mice (Mus musculus), treatment with O. vulgare was continued for 7 days. Autopsies were performed and re-isolation, gross lesion scoring and bacterial load in various organs were measured. Additionally, blood sample was analysed for hematological assays. Toxicity assessment of O. vulgare potential as medicine was done at 200 mg/kg and 400 mg/kg by evaluating liver and kidney functions. Bacterial load and gross lesion in lungs and heart were significantly low compared to positive control following O. vulgare treatment. Likewise, O. vulgare treated groups had hematological, neutrophil and TLC values similar to control groups. Increased AST, ALP and total bilirubin along with marked hepatocellular degeneration and distortion around the central vein, inflammatory cell infiltration, and cytoplasmic vacuolization of hepatic cells was observed at higher dose. It is concluded that crude extract of O. vulgare may contain beneficial secondary metabolites and in future may be explored for curing infectious diseases.

Origanum vulgare tem despertado grande interesse na academia e na indústria farmacêutica devido às suas propriedades antioxidantes, antifúngicas e antitumorais. O presente estudo teve como objetivo encontrar o potencial anti-MRSA e avaliações de toxicidade in vivo de O. vulgare. O extrato de O. vulgare foi usado para monitorar a atividade anti-MRSA em camundongos. Após infecção estabelecida por MRSA em camundongos (Mus musculus), o tratamento com O. vulgare foi continuado por 7 dias. As autópsias foram realizadas e o reisolamento, pontuação das lesões grosseiras e carga bacteriana em vários órgãos foram medidos. Além disso, a amostra de sangue foi analisada para ensaios hematológicos. A avaliação da toxicidade do potencial de O. vulgare como medicamento foi feita com 200 mg / kg e 400 mg / kg, avaliando as funções hepática e renal. A carga bacteriana e as lesões graves nos pulmões e no coração foram significativamente baixas em comparação com o controle positivo após o tratamento com O. vulgare. Da mesma forma, os grupos tratados com O. vulgare apresentaram valores hematológicos, de neutrófilos e de TLC semelhantes aos grupos de controle. Aumento de AST, ALP e bilirrubina total juntamente com degeneração hepatocelular marcada e distorção ao redor da veia central, infiltração de células inflamatórias e vacuolização citoplasmática de células hepáticas foram observados em doses mais altas. Conclui-se que o extrato bruto de O. vulgare pode conter metabólitos secundários benéficos e, no futuro, pode ser explorado para a cura de doenças infecciosas.

Enterotoxigenic methicillin resistant Staphylococcus aureus contamination in salted fish from Gwadar Balochistan / Contaminação de Staphylococcus aureus resistente à meticilina enterotoxigênica em peixes salgados de Gwadar Balochistan

Staphylococcus aureus is an important foodborne pathogen associated to food intoxication and other multiple infections in human being. Its presence in salted food is a serious issue due to its salt tolerance potential. A study was conducted to analyze the presence of enterotoxins producing drug resistance S. aureus in salted sea fish from Gwadar. Freshly persevered samples (n=50) of salted fish were subjected to analyze the presence of S. aureus using 16S rRNA and Nuc genes primers. The isolates were then evaluated for drug resistance and enterotoxins producing potential using specific primers for MecA (methicillin resistance gene), (SEA) staphylococcal enterotoxin A and (SEB) staphylococcal enterotoxin B genes. Total 13/50 (26%) of the samples were found positive for the presence of S. aureus, preliminary confirmed with biochemical profiling and finally with the help of target genes presence. The isolates were found showing 100% resistant to methicillin, which were molecularly confirmed by the presence of MecA gene present in genome. The isolates 5/13 (38%) were positive for SEA and 3/13 (23%) for SEB genes, whereas 2/13 (15%) were confirmed having both SEA and SEB genes in its genome. It was also confirmed that all the isolates were capable to form biofilm over the glass surfaces. It was concluded that the study confirmed the presence of enterotoxigenic methicillin resistance Staphylococcus aurous (MRSA) in salted fish product, that poses gross food safety concern. Preventive and control measures are necessary to handle this serious food safety concern.

Staphylococcus aureus é um importante patógeno de origem alimentar associado à intoxicação alimentar e outras infecções múltiplas em seres humanos. Sua presença em alimentos salgados é um problema sério devido ao seu potencial de tolerância ao sal. Um estudo foi realizado para analisar a presença de enterotoxinas produtoras de resistência a drogas S. aureus em peixes salgados do mar de Gwadar. Amostras recém-perseveradas (n = 50) de peixes salgados foram submetidas à análise da presença de S. aureus usando os primers dos genes 16S rRNA e Nuc. Os isolados foram então avaliados quanto à resistência a drogas e potencial de produção de enterotoxinas usando primers específicos para os genes MecA (gene de resistência à meticilina), (SEA) enterotoxina A estafilocócica e (SEB) enterotoxina B estafilocócica genes. Um total de 13/50 (26%) das amostras foi considerado positivas para a presença de S. aureus, confirmadas preliminarmente com perfis bioquímicos e finalmente com a ajuda da presença de genes-alvo. Os isolados foram encontrados com 100% de resistência à meticilina, os quais foram confirmados molecularmente pela presença do gene MecA no genoma. Os isolados 5/13 (38%) foram positivos para SEA e 3/13 (23%) para genes SEB, enquanto 2/13 (15%) foram confirmados tendo os genes SEA e SEB em seu genoma. Também foi verificado que todos os isolados foram capazes de formar biofilme sobre as superfícies de vidro. Concluiu-se que o estudo confirmou a presença de Staphylococcus aurous resistente à meticilina enterotoxigênica (MRSA) em produtos de peixe salgado, o que representa uma grande preocupação para a segurança alimentar. Medidas preventivas e de controle são necessárias para lidar com essa grave preocupação com a segurança alimentar.

Population structure of food-borne Staphylococcus aureus in China / 中华流行病学杂志

Objective: To understand the population structure of food-borne Staphylococcus (S.) aureus in China. Methods: Whole genome sequencing was used to analyze 763 food-borne S. aureus strains from 16 provinces in China from 2006 to 2020. Multilocus sequence typing (MLST), staphylococcal protein A gene (spa) typing, and staphylococcal chromosome cassettemec (SCCmec) typing were conducted, and minimum spanning tree based on ST types (STs) was constructed by BioNumerics 7.5 software. Thirty-one S. aureus strains isolated from imported food products were also included in constructing the genome phylogenetic tree. Results: A total of 90 STs (20 novel types) and 160 spa types were detected in the 763 S. aureus isolates. The 72 STs (72/90, 80.0%) were related to 22 clone complexes. The predominant clone complexes were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, accounting for 82.44% (629/763) of the total. The STs and spa types in the predominant clone complexes changed over the years. The methicillin-resistant S. aureus (MRSA) detection rate was 7.60%, and 7 SCCmec types were identified. The ST59-t437-Ⅳa (17.24%, 10/58), ST239-t030-Ⅲ (12.07%, 7/58), ST59-t437-Ⅴb (8.62%, 5/58), ST338-t437-Ⅴb (6.90%, 4/58) and ST338-t441-Ⅴb (6.90%, 4/58) were the main types in MRSA strains. The genome phylogenetic tree had two clades, and the strains with the same CC, ST, and spa types clustered together. All CC7 methicillin sensitive S. aureus strains were included in Clade1, while 21 clone complexes and all MRSA strains were in Clade2. The MRSA strains clustered according to the SCCmec and STs. The strains from imported food products in CC398, CC7, CC30, CC12, and CC188 had far distances from Chinese strains in the tree. Conclusions: In this study, the predominant clone complexes of food-borne strains were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, which overlapped with the previously reported clone complexes of hospital and community-associated strains in China, suggesting that close attention needs to be paid to food, a vehicle of pathogen transmission in community and food poisoning.

Analysis of Pathogenic Bacterial Spectrum, Drug Resistance and Risk Factors for Mortality of Bloodstream Infection in Patients with Hematologic Diseases / 中国实验血液学杂志

OBJECTIVE@#To analyze the pathogenic bacterial spectrum, drug resistance, and risk factors associated with multidrug-resistant bacterial infection and mortality in patients with hematologic diseases complicated by bloodstream infections, so as to provide reference for rational drug use and improving prognosis.@*METHODS@#Positive blood culture specimens of patients with hematologic diseases in two Class A tertiary hospitals of Shanxi province from January 2019 to December 2021 were retrospectively analyzed. Pathogen distribution, drug resistance and outcomes of patients with bloodstream infection were investigated, then the multivariate logistic analysis was performed to analyze the risk factors of multidrug-resistant bacterial infection and factors affecting prognosis.@*RESULTS@#203 strains of pathogens were identified, mainly Gram-negative bacteria (GNB) (69.46%, 141/203), of which Escherichia coli (E.coli) had the highest incidence (41.13%, 58/141), followed by Klebsiella pneumoniae (20.57%, 29/141) and Pseudomonas aeruginosa (12.77%, 18/141). Extended-spectrum beta-lactamase (ESBL)-producing E.coli and Klebsiella pneumoniae were 46.55% (27/58) and 37.93% (11/29), respectively. Carbapenem-resistant Gram-negative bacteria accounted for 10.64% (15/141). And Gram-positive bacteria accounted for 27.59% (56/203), Staphylococcus epidermidis, Streptococcus pneumoniae, and Staphylococcus aureus were the most frequently isolated pathogen among Gram-positive bacteria (14.29%, 12.50% and 10.71%, respectively), of which methicillin-resistant Staphylococcus aureus accounted for 33.33% (2/6), coagulase-negative staphylococci accounted for 87.50% (7/8), without vancomycin- or linezolid-resistant strain. Additionally, fungi accounted for 2.95% (6/203), all of which were Candida. Multidrug-resistant Gram-negative bacteria (MDR-GNB) accounted for 53.90% (76/141). Duration of neutropenia >14 days was a risk factor for developing MDR-GNB infection. The 30-day all-cause mortality was 10.84%. Multivariate logistic regression analysis showed that the significant independent risk factors for mortality were age≥60 years (P <0.01, OR =5.85, 95% CI: 1.80-19.07) and use of vasopressor drugs (P <0.01, OR =5.89, 95% CI: 1.83-18.94).@*CONCLUSION@#The pathogenic bacteria of bloodstream infection in patients with hematological diseases are widely distributed, and the detection rate of multidrug-resistant bacteria is high. The clinicians should choose suitable antibiotics according to the results of bacterial culture and antibiotic susceptibility test.

Tratamiento de las infecciones hospitalarias por staphylococcus aureus meticilino resistente / Treatment of hospital-acquired methicillin-resistant staphylococcus aureus infections / Tratamento de infecções por Staphylococcus aureus resistentes à meticilina, adquiridas em hospitais

Introducción: la infección por Staphylococcus aureus meticilino resistente, una de las principales bacterias causantes de infecciones hospitalarias, se ha convertido en una preocupación mundial dada la alta tasa de morbilidad y mortalidad que produce. La resistencia bacteriana es un factor que agrava la problemática de infecciones hospitalarias y se asocia fundamentalmente al uso inadecuado de antibióticos. El uso prudente de los mismos ayuda a controlar la resistencia bacteriana, sin embargo, cada vez se detectan más cepas resistentes a diversos antibióticos. Se realiza una revisión de tratamientos antibióticos disponibles para las infecciones hospitalarias producidas por Staphylococcus aureus meticilino resistente en paciente adulto, con la finalidad de proporcionar una guía sobre los mismos, que permita un uso racional de los antibióticos disponibles evitando así que se continúe desarrollando el fenómeno de resistencia bacteriana. Metodología: se realizó un estudio observacional, descriptivo, de tipo revisión literaria, restringiéndose la búsqueda a guías de práctica clínica. Para conocer las guías existentes en Uruguay se consultó la Cátedra de Enfermedades Infecciosas de la Facultad de Medicina, Universidad de la República y en el Ministerio de Salud Pública. Se encontraron y analizaron guías de diferentes países. Existe acuerdo en los lineamientos generales del tratamiento farmacológico de las infecciones hospitalarias por Staphylococcus aureus meticilino resistente. Resultados: en Uruguay no existen guías propias de tratamiento de las infecciones hospitalarias por Staphylococcus aureus meticilino resistente. Se utiliza como referencia la guía publicada por la Infectious Diseases Society of America. Discusión: algunos de los antibióticos recomendados en las guías analizadas no se encuentran disponibles en nuestro país, como es el caso de daptomicina, telavancina y cloxacilina. En particular, el no disponer de daptomicina podría llegar a dificultar el tratamiento de infecciones en las cuales la CIM de vancomicina sea mayor a 1.5 mg/L. Conclusiones: por lo tanto, se considera conveniente y necesario pautar el tratamiento de dichas infecciones, acorde a las posibilidades, a la epidemiología de nuestro país y a los patrones de resistencia a ésta bacteria, para unificar la práctica clínica y hacer un uso racional de los antibióticos de manera de evitar promover el fenómeno de resistencia microbiana.

Introduction: infection by methicillin-resistant Staphylococcus aureus, one of the main bacteria causing hospital infections, has become a worldwide concern due to the high morbidity and mortality rate it produces. Bacterial resistance is a factor that aggravates the problem of hospital infections and is mainly associated with the inappropriate use of antibiotics. The prudent use of antibiotics helps to control bacterial resistance; however, more and more strains resistant to different antibiotics are being detected. A review of available antibiotic treatments for hospital infections caused by methicillin-resistant Staphylococcus aureus in adult patients was carried out in order to provide a guide for a rational use of available antibiotics, thus avoiding further development of the phenomenon of bacterial resistance. Methodology: an observational, descriptive, literature review type study was carried out, restricting the search to clinical practice guidelines. In order to know the existing guidelines in Uruguay, the Department of Infectious Diseases of the School of Medicine, University of the Republic and the Ministry of Public Health were consulted. Guidelines from different countries were found and analyzed. There is agreement on the general guidelines for pharmacological treatment of hospital infections caused by methicillin-resistant Staphylococcus aureus. Results: in Uruguay there are no guidelines for the treatment of hospital infections caused by methicillin-resistant Staphylococcus aureus. The guidelines published by the Infectious Diseases Society of America are used as a reference. Discussion: some of the antibiotics recommended in the guidelines analyzed are not available in our country, as is the case of daptomycin, telavancin and cloxacillin. In particular, the unavailability of daptomycin could make the treatment of infections in which the MIC of vancomycin is higher than 1.5 mg/L more difficult. Conclusions: therefore, it is considered convenient and necessary to establish guidelines for the treatment of such infections, according to the possibilities, to the epidemiology of our country and to the resistance patterns to this bacterium, in order to unify clinical practice and make a rational use of antibiotics so as to avoid promoting the phenomenon of microbial resistance.

Introdução: a infecção por Staphylococcus aureus resistente à meticilina, uma das principais bactérias causadoras de infecções hospitalares, tornou-se uma preocupação mundial devido à alta taxa de morbidade e mortalidade que ela causa. A resistência bacteriana é um fator que agrava o problema das infecções adquiridas nos hospitais e está principalmente associada ao uso inadequado de antibióticos. O uso prudente de antibióticos ajuda a controlar a resistência bacteriana, entretanto, cada vez mais estirpes resistentes a vários antibióticos estão sendo detectadas. É realizada uma revisão dos tratamentos antibióticos disponíveis para infecções hospitalares causadas por Staphylococcus aureus resistente à meticilina em pacientes adultos, com o objetivo de fornecer um guia para o uso racional dos antibióticos disponíveis, evitando assim o desenvolvimento posterior do fenômeno de resistência bacteriana. Metodologia: foi realizado um estudo observacional, descritivo, do tipo revisão de literatura, restringindo a busca às diretrizes da prática clínica. O Departamento de Doenças Infecciosas da Faculdade de Medicina da Universidade da República e o Ministério da Saúde Pública foram consultados para as diretrizes existentes no Uruguai. Foram encontradas e analisadas diretrizes de diferentes países. Há acordo sobre as diretrizes gerais para o tratamento farmacológico de infecções hospitalares causadas por Staphylococcus aureus resistente à meticilina. Resultados: no Uruguai não há diretrizes para o tratamento de infecções por Staphylococcus aureus resistentes à meticilina adquiridas em hospitais. As diretrizes publicadas pela Sociedade de Doenças Infecciosas da América são usadas como referência. Discussão: alguns dos antibióticos recomendados nas diretrizes analisadas não estão disponíveis na Espanha, tais como daptomicina, telavancina e cloxacilina. Em particular, a indisponibilidade da daptomicina poderia dificultar o tratamento de infecções nas quais a MIC da vancomicina é maior que 1,5 mg/L. Conclusões: portanto, considera-se conveniente e necessário estabelecer diretrizes de tratamento para estas infecções, de acordo com as possibilidades, a epidemiologia de nosso país e os padrões de resistência a esta bactéria, a fim de unificar a prática clínica e fazer uso racional dos antibióticos, a fim de evitar a promoção do fenômeno da resistência microbiana.

Prevalencia de portación nasal de Staphylococcus aureus sensible y resistente a la meticilina en candidatos a artroplastia total de cadera o rodilla / Prevalence of nasal carriage of methicillin-sensitive and methicillin-resistant Staphylococcus aureus in candidates for total hip or knee arthroplasty

INTRODUCIÓN Las infecciones perioperatorias en cirugía de reemplazo articular son fuente importante de morbimortalidad, así como de altos costos económicos y sociales, tanto para el paciente como para su entorno. La colonización preoperatoria por Staphylococcus aureus ha sido reconocida como un factor de riesgo importante para desarrollar una infección de sitio quirúrgico.El objetivo de este estudio es conocer la prevalencia de portación nasal de S. aureus, tanto sensible a la meticilina (SASM) como resistente a la meticilina (SARM), en pacientes candidatos a cirugía de reemplazo articular de cadera o rodilla. MATERIALES Y MÉTODOS Se realizó un estudio observacional de una cohorte retrospectiva de pacientes con indicación de artroplastia total de cadera (ATC) y rodilla (ATR) electiva por artrosis severa en un hospital público de Chile. Los pacientes fueron sometidos a tamizaje preoperatorio de portación, cultivándose muestras obtenidas mediante hisopado de ambas fosas nasales. Los datos del laboratorio fueron recopilados y presentados como porcentaje de portación de S. aureus. RESULTADOS Se estudiaron 303 pacientes consecutivos de ATC y 343 de ATR. En total, 483 de los 646 pacientes (74,7%) tuvieron estudio preoperatorio de portación nasal. Se identificaron 123 pacientes (25,4%) portadores de S. aureus, de los cuales sólo 2 (0,41%) casos correspondieron a SARM. CONCLUSIÓN La prevalencia de portación nasal de S. aureus obtenida fue de 25%, similar a lo reportado en otras series. La prevalencia de SARM (0.41%), sin embargo, estuvo bajo lo descrito en la literatura internacional (0,6­6%). Sería de utilidad, dada la alta prevalencia de portación descrita en nuestro trabajo y de acuerdo a evidencia publicada recientemente, realizar protocolos de descolonización universales, sin necesidad de realizar tamizaje preoperatorio.

INTRODUCTION Surgical-site infections in joint replacement surgery are an important source of morbidity and mortality that entail high economic and social burden both for the patient and their environment. Preoperative colonization by Staphylococcus aureus has been recognized as an important risk factor for the development of surgical-site infection. The aim of the present study is to determine the prevalence of nasal colonization by S. aureus, both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) in patients who are candidates for total replacement of the hip or knee joints. MATERIALS AND METHODS A retrospective observational study of a cohort of 646 patients with an indication to undergo total hip arthroplasty (THA) or total knee arthroplasty (TKA) due to severe osteoarthritis was performed in a Public Hospital in Chile. The patients were submitted to a preoperative screening for S. aureus carriage, and the culture samples were obtained by swabbing both nostrils. The laboratory data was collected and presented as a percentage of carriage. RESULTS We consecutively examined 303 THA and 343 TKA patients. A total of 483 of the 646 patients (74.7%) underwent a preoperative study of nasal carriage. We identified 123 (25.4%) S. aureus carriers, and only found 2 (0.41%) cases corresponding to MRSA. CONCLUSION We found a prevalence of nasal carriage of S. aureus of 25.4%, a rate similar to that reported in other series. The prevalence of MRSA (0.41%), however, was lower than that reported in the international literature (0.6­6%). Given the high prevalence of carriage described in our work and according to recently published data, it would be worthwhile to carry out universal decolonization protocols, without the need for preoperative screening.

Portación nasal de Staphylococcus aureus en el personal de salud de áreas críticas de un Hospital Pediátrico durante julio-setiembre 2018 / Nasal carriage of Staphylococcus aureus in health personnel in critical areas of a Pediatric Hospital during July-September 2018 / Transporte nasal de Staphylococcus aureus em profissionais de saúde em áreas críticas de um Hospital Pediátrico durante julho-setembro de 2018

Las infecciones intrahospitalarias (IIH) son causa de elevada morbimortalidad y representan un problema sanitario importante. El personal de salud es reservorio y potencial transmisor de los agentes etiológicos de las mismas. S. aureus es uno de los microorganismos implicados, por lo tanto es importante conocer la frecuencia de portación en el personal de salud y establecer el perfil de susceptibilidad antimicrobiana para contribuir con la elaboración de medidas de prevención incluyendo actividades educativas. Objetivo: Conocer la frecuencia de portación de S. aureus, distribución y antibiotipos de las cepas presentes en el personal sanitario del Hospital Pediátrico de Referencia (HPR). Materiales y métodos: Se realizó un estudio descriptivo durante el periodo julio-setiembre del año 2018. Se incluyeron muestras de hisopados nasales de trabajadores de la salud de distintas áreas de internación que consintieron participar en el estudio. Se excluyeron aquellos que recibieron antibióticos dentro de los 3 meses previos al estudio. Las muestras fueron sembradas en agar sangre ovina al 5% (ASO) y se incubaron a 35-37ºC en aerobiosis por 24-48 horas. La identificación de las colonias sospechosas de Staphylococcus aureus por métodos convencionales y MALDI-TOF. El patrón de resistencia antimicrobiana de S. aureus se detectó por disco-difusión. En los cultivos resistentes a meticilina (SAMR) se determinó la presencia del gen mecA y se realizó la tipificación del SCCmec por pruebas de reacción en cadena de polimerasa. Resultados: Se obtuvieron 225 hisopados a partir de 225 trabajadores, presentaron desarrollo 212. En 49 se recuperaron cultivos de S. aureus. Correspondieron a SAMR 11 de las 49 cepas, todas portaban el gen mecA. Hubo predominio en el personal de enfermería (7/11), en los servicios de hemato-oncología (3/11) y cuidados intensivos neonatales (4/11). Asociaron resistencia a macrólidos y clindamicina 8 de 11 aislamientos SAMR, a gentamicina 2 y a mupirocina uno. El SCCmec más frecuentemente identificado fue el tipo IV (7/11). Conclusiones: Los resultados muestran la presencia de cepas SAMR entre el personal de salud del CHPR y aportan información complementaria para efectuar prevención y control de las IIH, actuando sobre todo en el personal de salud encargado de la atención de pacientes susceptibles.

Hospital-acquired infections (IIH) are a cause of high morbidity and mortality and represent a major health problem. Health personnel are reservoirs and potential transmitters of their etiological agents. S. aureus is one of the microorganisms involved, therefore it is important to know the frequency of carriage in health personnel and establish the antimicrobial susceptibility profile to contribute to the development of prevention measures, including educational activities. Objective: To know the frequency of carriage of S. aureus, distribution and antibiotypes of the strains present in the health personnel of the Reference Pediatric Hospital (HPR). Materials and methods: A descriptive study was carried out during the period July-September 2018. Nasal swab samples from health workers from different hospitalization areas who agreed to participate in the study were included. Those who received antibiotics within 3 months prior to the study were excluded. The samples were seeded in 5% sheep blood agar (ASO) and incubated at 35-37ºC in aerobiosis for 24-48 hours. Identification of suspicious Staphylococcus aureus colonies by conventional methods and MALDI-TOF. The antimicrobial resistance pattern of S. aureus was detected by disc diffusion. In methicillin-resistant cultures (MRSA), the presence of the mecA gene was determined and SCCmec was typified by polymerase chain reaction tests. Results: 225 swabs were obtained from 225 workers, 212 showed development. S. aureus cultures were recovered from 49. 11 of the 49 strains corresponded to MRSA, all of them carried the mecA gene. There was a predominance in the nursing staff (7/11), in the hematology-oncology services (3/11) and neonatal intensive care (4/11). They associated resistance to macrolides and clindamycin in 8 of 11 MRSA isolates, 2 to gentamicin, and 1 to mupirocin. The most frequently identified SCCmec was type IV (7/11). Conclusions: The results show the presence of MRSA strains among the health personnel of the CHPR and provide complementary information to carry out prevention and control of IIH, acting especially on the health personnel in charge of the care of susceptible patients.

As infecções hospitalares (HII) são causa de alta morbidade e mortalidade e representam um importante problema de saúde. Os profissionais de saúde são reservatórios e potenciais transmissores de seus agentes etiológicos. O S. aureus é um dos micro-organismos envolvidos, por isso é importante conhecer a frequência de portadores em profissionais de saúde e estabelecer o perfil de suscetibilidade antimicrobiana para contribuir no desenvolvimento de medidas de prevenção incluindo atividades educativas. Objetivo: Conhecer a frequência de portadores de S. aureus, distribuição e antibiótipos das cepas presentes no pessoal de saúde do Hospital Pediátrico de Referência (HPR). Materiais e métodos: Foi realizado um estudo descritivo durante o período de julho a setembro de 2018. Foram incluídas amostras de swab nasal de profissionais de saúde de diferentes áreas de internação que concordaram em participar do estudo. Aqueles que receberam antibióticos nos 3 meses anteriores ao estudo foram excluídos. As amostras foram semeadas em 5% de ágar sangue de carneiro (ASO) e incubadas a 35-37ºC em aerobiose por 24-48 horas. Identificação de colônias suspeitas de Staphylococcus aureus por métodos convencionais e MALDI-TOF. O padrão de resistência antimicrobiana de S. aureus foi detectado por difusão em disco. Em culturas resistentes à meticilina (MRSA), a presença do gene mecA foi determinada e SCCmec foi tipificado por testes de reação em cadeia da polimerase. Resultados: 225 swabs foram obtidos de 225 trabalhadores, 212 apresentaram desenvolvimento. Culturas de S. aureus foram recuperadas de 49. 11 das 49 cepas correspondiam a MRSA, todas carregavam o gene mecA. Houve predominância na equipe de enfermagem (7/11), nos serviços de hematologia-oncologia (3/11) e de terapia intensiva neonatal (4/11). Eles associaram resistência a macrolídeos e clindamicina em 8 de 11 isolados de MRSA, 2 à gentamicina e 1 à mupirocina. O SCCmec mais frequentemente identificado foi o tipo IV (7/11). Conclusões: Os resultados mostram a presença de cepas de MRSA entre os profissionais de saúde do CHPR e fornecem informações complementares para realizar a prevenção e controle da HII, atuando principalmente sobre os profissionais de saúde responsáveis ​​pelo atendimento de pacientes suscetíveis.

Resistencia antimicrobiana y producción porcina de cría intensiva / Antimicrobial resistance and intensive swine production: mini review

Introducción: el impacto de la resistencia antimicrobiana (RAM) generará un aumento de las muertes relacionadas de 10 millones anuales hacia 2050. El 70% de la dispensación de antimicrobianos (ATB) se utiliza en la agroveterinaria y no en salud humana. Es fundamental conocer la portación de RAM en trabajadores de cría de animales y en los animales, para acciones tempranas de salud pública. Métodos: bajo metodología PRISMA se realizó la búsqueda bibliográfica en distintas fuentes disponibles hasta octubre de 2020. Se priorizaron revisiones sistemáticas, metanálisis, ensayos clínicos y estudios observacionales para determinar la RAM en trabajadores de cría de cerdos. De 990 artículos identificados se incluyeron 8 estudios. Resultados: la tasa de colonización por Staphylococcus aureus resistente a la meticilina (SAMR) en trabajadores fue mayor que la de la población general. La prevalencia de SAMR fue significativamente mayor en trabajadores en contacto directo con animales y los de granjas de cría intensiva con respecto a los de extensiva. En cerdos, la prevalencia de RAM en cría intensiva fue significativamente mayor que la de los de cría extensiva. También fue significativa la asociación entre el suministro de antibióticos en la cría intensiva y la presencia de RAM. Las granjas de más de 1250 cerdos presentaron mayor prevalencia de RAM (p < 0,001). El fenotipo de SAMR en cerdos, trabajadores y el ambiente fue el mismo. Conclusiones: existe evidencia de asociación entre la producción agrícola de cría intensiva y la RAM en cerdos y trabajadores. No se encontraron estudios de vigilancia epidemiológica en la Argentina en trabajadores de cría de animales. (AU)

Introduction: it is estimated that the impact of antimicrobial resistance (AMR) will generate an increase of 10 million deaths by 2050, being reflected to a greater extent in low-income countries. 70% of the annual use of antimicrobials is concentrated in agroveterinary but not in human health. Considering the presence of AMR in ranchers and agricultural workers is essential for early public health actions. Methods: using the PRISMA methodology, bibliography was searched in different sources until October 2020. Systematic reviews, meta-analyses, clinical trials and observational studies were prioritized to determine AMR in pig workers. Eight studies of the 990 found have been included. Results: the rate of colonization by methicillin-resistant Staphylococcus aureus (MRSA) in farming workers was higher than the general population. MRSA prevalence was significantly higher in workers who reported direct contact with animals. And also in those workers of intensive farms compared to those of extensive farms. The same situation is observed in swines, in which the prevalence of AMR in intensive farming was significantly higher than in extensive farming. The association between the supply of antibiotics in intensive farming workers and the presence of AMR was also significant. Farms with more than 1,250 swines had a higher prevalence of AMR (p<0.001). The MRSA phenotype found in swine, agricultural workers, and the environment was the same. Conclusions: there is scientific evidence of an association between agricultural production in intensive livestock farming and AMR in swine and farming workers. There aren't Argentine studies of epidemiological surveillance in farming workers. (AU)

Susceptibility to Vancomycin of Biofilm Producing Staphylococci Isolated from Tertiary Care Hospital of Nepal / Susceptibilidad a la vancomicina de estafilococos productores de biopelículas aislados del hospital de atención terciaria de Nepal

Background: Methicillin resistance and biofilm-producing Staphylococci are emerging as multidrug-resistant strains narrowing the efficacy of antimicrobial therapy. Although vancomycin is used as the drug of choice to treat such isolates, different studies worldwide have documented the emergence of strains that are intermediately susceptible or resistant to this antibiotic. Objective: The study aimed to determine the minimum inhibitory concentration of vancomycin to methicillin-resistant and biofilm-producing staphylococci isolated from different clinical specimens. Methods: 375 staphylococci isolated from different clinical specimens over one year were included in the study. Biofilm formation was determined by the Tissue culture plate method (TCP), and ica genes were identified by Polymerase Chain Reaction (PCR). Antibiotic susceptibility and methicillin resistance were done following Clinical and Laboratory Standards Institute (CLSI) guidelines. The minimum inhibitory concentration (MIC) of vancomycin in all isolates was determined by the agar dilution method. Results:Among 375 Staphylococci studied, 43% and 57% represented S. aureus and Coagulase-Negative Staphylococci (CNS), respectively. The rate of Methicillin-Resistant S. aureus (MRSA) and Methicillin-Resistant Coagulase Negative Staphylococci (MRCNS) were 81.4% and 66.8% respectively and determined by the disc diffusion method. The most potential antibiotics were tetracycline and chloramphenicol showing sensitivity to more than 90% isolates. The Minimum Inhibitory Concentration (MIC) value of oxacillin for staphylococci ranged from 0.125-32 µg/ml. Oxacillin agar diffusion method showed 51.6% and 79.9% isolates as MRSA and MRCNS, respectively, revealing a very high percentage of S. aureus and CNS isolates as methicillin-resistant. All isolates had susceptible vancomycin MICs that ranged from 0.125-2 µg/ml. Two S. aureus isolated from Central Venous Catheter (CVC) and catheter specimens were detected with intermediate susceptibility to vancomycin. Similarly, three CNS isolated from blood, CVC, and wound/pus (w/p) were intermediately susceptible to vancomycin. Strong biofilm formation was observed in 22.1% of clinical isolates, and the ica gene was detected among 22.9% of isolates. Only one S. aureus detected as a biofilm producer by the TCP method was found to have intermediate susceptibility to vancomycin. Conclusions: The increment in vancomycin MIC among methicillin-resistant and biofilm-producing staphylococci is alarming. Strict control measures to prevent methicillin-resistant isolates spread and routine surveillance for vancomycin-resistant isolates must be incorporated in hospitals to prevent antimicrobial treatment failure

Antecedentes: Los estafilococos resistentes a la meticilina y productores de biopelículas están surgiendo como cepas multirresistentes que reducen la eficacia del tratamiento antimicrobiano. Aunque la vancomicina se utiliza como fármaco de elección para tratar dichos aislados, diferentes estudios realizados en todo el mundo han documentado la aparición de cepas intermedias susceptibles o resistentes a este antibiótico. Objetivo: El estudio tenía como objetivo determinar la concentración mínima inhibitoria de la vancomicina para los estafilococos resistentes a la meticilina y productores de biofilm aislados de diferentes muestras clínicas. Métodos: Se incluyeron en el estudio 375 estafilococos aislados de diferentes muestras clínicas durante un año. La formación de biopelículas se determinó mediante el método de la placa de cultivo de tejidos (TCP), y los genes ica se identificaron mediante la reacción en cadena de la polimerasa (PCR). La susceptibilidad a los antibióticos y la resistencia a la meticilina se realizaron siguiendo las directrices del Clinical and Laboratory Standards Institute (CLSI). La concentración inhibitoria mínima (MIC) de vancomicina en todos los aislados se determinó por el método de dilución en agar. Resultados:Entre los 375 estafilococos estudiados, el 43% y el 57% representaban S. aureus y estafilococos coagulasa-negativos (ECN), respectivamente. La tasa de S. aureus resistente a la meticilina (SARM) y de estafilococos coagulasa negativos resistentes a la meticilina (ECNM) fue del 81,4% y el 66,8%, respectivamente, y se determinó por el método de difusión de discos. Los antibióticos más potenciales fueron la tetraciclina y el cloranfenicol, que mostraron una sensibilidad superior al 90% de los aislados. El valor de la concentración inhibitoria mínima (CIM) de la oxacilina para los estafilococos osciló entre 0,125-32 µg/ml. El método de difusión en agar de la oxacilina mostró que el 51,6% y el 79,9% de los aislados eran SARM y MRCNS, respectivamente, lo que revela que un porcentaje muy elevado de los aislados de S. aureus y CNS son resistentes a la meticilina. Todos los aislados tenían MIC de vancomicina susceptibles que oscilaban entre 0,125-2 µg/ml. Se detectaron dos S. aureus aislados de muestras de catéteres venosos centrales (CVC) y catéteres con una susceptibilidad intermedia a la vancomicina. Del mismo modo, tres S. aureus aislados de sangre, CVC y herida/pus (w/p) fueron intermedianamente susceptibles a la vancomicina. Se observó una fuerte formación de biopelículas en el 22,1% de los aislados clínicos, y se detectó el gen ica en el 22,9% de los aislados. Sólo un S. aureus detectado como productor de biopelículas por el método TCP resultó tener una susceptibilidad intermedia a la vancomicina. Conclusiones: El incremento de la MIC de vancomicina entre los estafilococos resistentes a la meticilina y productores de biofilm es alarmante. Para evitar el fracaso del tratamiento antimicrobiano, deben incorporarse en los hospitales medidas de control estrictas para prevenir la propagación de los aislados resistentes a la meticilina y una vigilancia rutinaria de los aislados resistentes a la vancomicina

Vigilancia epidemiológica de Staphylococcus aureus y resistencia antibiótica en ambientes nosocomiales / Epidemiological surveillance of Staphylococcus aureus and the antibiotic resistence in nosocomial environments / Vigilância epidemiológica de Staphylococcus aureus e resistência a antibióticos em ambientes nosocomiais

Uno de los microrganismos más importantes en Infecciones Asociadas a la Atención en Salud (IAAS) es Staphylococcus aureus, una bacteria aerobia Gram positiva, resistente a diferentes condiciones ambientales. Objetivo. Identificar Staphylococcus aureus y su resistencia a los principales antibióticos Betalactámicos, aislada en áreas inertes. Materiales y métodos. Se realizó análisis fenotípico, antibiograma y métodos moleculares como: Extracción de ADN mediante Lisis Alcalina, identificación molecular para la amplificación de los genes tanto de identificación de la bacteria (nucA y femB), como de resistencia de antibióticos (blaZ, mecA y vanA) mediante PCR punto final, la separación de los amplicones se realizó mediante electroforesis en gel de Agarosa, los productos de la PCR se revelaron mediante la utilización de transiluminador UV. Resultados. De 200 muestras tomadas se obtuvo dos muestras positivas (1%) para Staphylococcus aureus, con el 100% de resistencia a penicilina y sensible a todos los demás antibióticos testeados. Conclusiones. La identificación de la bacteria y su resistencia hoy en día se realiza mayormente mediante métodos moleculares, lo cual no descarta la identificación fenotípica que, en este caso, determinó resultados importantes como lo es la prueba D-test positivo. La resistencia a fármacos betalactámicos se considera como un serio problema de salud, por lo tanto, se requiere de una vigilancia epidemiológica constante.

Staphylococcus aureus is one of the most important microorganisms related to Health Care Associated Infections (HCAI), it is a Gram-positive aerobic bacterium, highly resistant to the outer environment. Objective. Identify Staphylococcus aureus and its resistance to the most common beta-lactam antibiotics in isolated, inert areas. Materials and methods. Phenotypic analysis, antibiogram and molecular testing such as: DNA extraction by Alkaline Lysis, molecular identification for the amplification of genes both for identification of Staphylococcus aureus (nucA and femB), and for antibiotic resistance (blah, mega and vanA) by PCR, the disassociation of the amplicons was preforming by Agarose gel electrophoresis and results were shown in a UV translluminator. Results. From the 200 samples taken, two showed positive (1%) for Staphylococcus aureus, with 100% penicillin-resistant and sensitive to all other antibiotics tested. Conclusions. Nowadays identification of the bacteria and its resistance is carried out mostly through molecular testing, ruling out phenotypic identification, which in this case it determined important results such as the positive D-test. Resistance to beta-lactam drugs is considered a serious health issue, therefore it requires a safer epidemiological vigilance, an increase in sensitivity testing and the accuracy of results. It is recommended to carry out the D-test in laboratories to identify resistance mechanisms and to guide health personnel to select the best option regarding specific and effective treatment for patients affected with MRSA.

Um dos microrganismos mais importantes em Infecções Associadas à Saúde (HAIs) é o Staphylococcus aureus, uma bactéria aeróbica gram-positiva resistente a diferentes condições ambientais. Objetivo. Identificar Staphylococcus aureus e sua resistência aos principais antibióticos beta-lactam, isolados em áreas inertes. Materiais e métodos. Análise fenotípica, antibiograma e métodos moleculares foram realizados tais como: extração de DNA por Alkaline Lysis, identificação molecular para a amplificação dos genes tanto da identificação da bactéria (nucA e femB), e resistência a antibióticos (blaZ, mecA e vanA) pelo ponto final da PCR, a separação dos amplicons foi realizada por eletrofose em gel de Agarose, os produtos PCR foram revelados usando transiluminador UV. Resultados. De 200 amostras colhidas, duas amostras positivas (1%) foram obtidas para o Staphylococcus aureus, com 100% de resistência à penicilina e sensível a todos os outros antibióticos testados. Conclusões. A identificação da bactéria e sua resistência hoje é realizada principalmente por métodos moleculares, o que não exclui a identificação fenotípica que, neste caso, determinou resultados importantes como o teste D positivo. A resistência aos medicamentos beta-lactam é considerada um grave problema de saúde, portanto, é necessária uma vigilância epidemiológica constante.

Virulence, biofilm formation ability and antimicrobial resistance of staphylococcus aureus isolated from cell phones of university students / Virulência, capacidade de formação de biofilme e resistência antimicrobiana de staphylococcus aureus isolado de telefones celulares de estudantes universitários

INTRODUCTION: Contamination of cell phones can contribute to the dissemination of pathogens in the community and/or hospital environment. OBJECTIVE: To characterize Staphylococcus aureus strains isolated from cell phones of university students. METHODS: Samples were collected from 100 cell phones. Detection of genes associated with virulence factors such as biofilm formation (icaA and icaD), enterotoxins production (SEA, SEB, SEC, and SED), and resistance to methicillin (mecA and mecC) was performed in S. aureus isolates by PCR. Typing mecA gene performed by multiplex PCR. Susceptibility to antimicrobials and biofilm formation rate also evaluated by using disk diffusion test and crystal violet staining. RESULTS: S. aureus was present in 40% of the total samples and about 70% of them belonged to Nursing students. Of the isolates, 85% presented resistance to penicillin and 50% were classified as moderate biofilm producers. In addition, 92.5% of isolates contained the gene icaA and 60% of the gene icaD. Approximately 25% of the isolates presented the mecA gene. Typing of the mecA gene showed the presence of staphylococcal chromosome cassette SCCmec I and c III respectively in 20% and 10% of the isolates. 70% of the samples could not be typed by the technique. Regarding the enterotoxins, the most prevalent gene was SEA (30%) followed by the SEC gene (2.5%). The presence of SED and SEB genes not observed in any of the isolates. CONCLUSION: The cleaning and periodic disinfection of cell phones can contribute to the reduction of the risk of nosocomial infection.

INTRODUÇÃO: A contaminação de celulares pode contribuir para a disseminação de patógenos na comunidade e/ou ambiente hospitalar. OBJETIVO: Caracterizar cepas de Staphylococcus aureus de telefones celulares de estudantes universitários. MÉTODOS: Foram coletadas amostras de 100 telefones celulares. Detecção de genes associados a fatores de virulência quanto a: formação de biofilme (icaA e icaD), produção de enterotoxinas (SEA, SEB, SEC e SED) e resistência à meticilina (mecA e mecC) foi realizada em isolados de S. aureus por PCR. A Tipagem do gene mecA foi realizada por PCR multiplex. A susceptibilidade a antimicrobianos e a taxa de formação de biofilme pelo teste de difusão em disco e coloração com cristal violeta. RESULTADOS: S. aureus esteve presente em 40% do total de amostras, destas, 70% pertenciam a estudantes do curso de enfermagem. Dos isolados, 85% apresentaram resistência à penicilina e 50% foram classificados com moderada formação de biofilme. Além disso, 92,5% dos isolados continham o gene icaA e 60% o gene icaD. Aproximadamente 25% dos isolados apresentaram o gene mecA. A tipagem do gene mecA mostrou a presença do cassete cromossômico estafilocócico SSCmec I e III em respectivamente 20% e 10% dos isolados. 70% das amostras não puderam ser identificadas pela técnica. Das enterotoxinas, o gene mais prevalente foi o SEA (30%), seguido pelo gene SEC (2.5%). A presença dos genes SED e SEB não foi observada nos isolados. CONCLUSÃO: A limpeza e desinfecção periódica dos telefones celulares podem contribuir para a redução do risco de infecção nosocomiais.

Características clínicas y microbiológicas de infecciones de piel y partes blandas en pacientes pediátricos de dos hospitales de Buenos Aires / Skin and soft tissue infections in pediatrics

Las infecciones de piel y partes blandas (IPPB) en niños son una de las principales causas de prescripción de antimicrobianos. El objetivo del estudio fue describir las características clínicas y microbiológicas de las IPPB ambulatorias de niños asistidos en dos hospitales zonales. Se realizó un estudio prospectivo entre el 1/11/2017 y el 1/11/2018. Se incluyeron pacientes entre 1 mes y 15 años internados en dos hospitales. Se evaluó: edad, sexo, localidad, factores predisponentes, tipo de IPPB, muestras biológicas realizadas, aislamiento microbiológico, tratamiento empírico indicado y evolución del cuadro. Se realizó antibiograma y determinación genética. Se calculó chi2, IC95, OR; α=5%. N= 94. 58,7% masculinos. 12 pacientes <1 año, 85 >1 año (promedio de edad 4 años, 1-15). El 36% de Tandil y 63,8% de Florencio Varela. El 59,6% corresponden a IPPB purulentas. Se aislaron microorganismos en un 59,6%. Los aislamientos principales: SAMR (40,4%), SAMS (7,4%), S. agalactiae (2,1%) y S. pyogenes (2,1%). El 100% de SAMR son portadores de gen mecA y SCCmec tipo IV, sin multirresistencia. No hubo diferencia estadística entre los factores de riesgo evaluados para el desarrollo de IPPB por SAMR. El 52,1% de los niños recibió tratamiento antibiótico combinado, siendo la más indicada TMS-SMX + CLI en 36 eventos. (38,3%). La evolución fue favorable: no hubo diferencia significativa entre el subgrupo que se aisló SAMR y el que no se aisló SAMR; 91,9% (34/37) y 92,6% (50/54) correspondientemente (chi2: 0,01; p= 0,97 IC95: 0,26-3,88). El principal agente etiológico fue SAMRco, debiendo adecuar los tratamientos a este microorganismo.

Skin and soft tissue infections (SSIs) in children are one of the main causes of antimicrobial prescription. The aim of the study was to describe the clinical and microbiological characteristics of outpatient SSIs in children attended in two hospitals. A prospective study was conducted between 11/1/2017 and 11/1/2018. Patients between 1 month and 15 years old, hospitalized were included. We evaluated: age, sex, locality, predisposing factors, type of IPPB, biological samples taken, microbiological isolation, empirical treatment indicated and evolution of the condition. An antibiogram and genetic determination were performed. Chi2, CI95, OR; α=5% were calculated. N= 94. 58.7% male. 12 patients <1 year, 85 >1 year (mean age 4 years, 1-15). 36% were from Tandil and 63.8% from Florencio Varela. 59.6% corresponded to purulent SSIs. The diagnostic yield was 59.6%. Main isolates: MRSA (40.4%), MSSA (7.4%), S. agalactiae (2.1%) and S. pyogenes (2.1%). 100% of MRSA carried the mecA gene and SCCmec type IV, with no multidrug resistance. There was no statistical difference between the risk factors evaluated. 52.1% of children received combined antibiotic treatment, the most indicated being TMS-SMX + CLI in 36 events. (38,3%). Evolution was favorable: there was no significant difference between the subgroup that isolated MRSA and the subgroup that did not isolate MRSA; 91.9% (34/37) and 92.6% (50/54) respectively (chi2: 0.01; p= 0.97 CI95: 0.26-3.88). The main etiological agent was MRSA, and treatments should be adapted to this microorganism

Antibacterial activity of Lactobacillus plantarum BS25, Pediococcus acidilactici S3 crude, and partially-purified cell-free supernatants against methicillinsusceptible and methicillin-resistant Staphylococcus aureus strains

Background@#The rising public health threat brought about by antibiotic resistance, such as of Staphylococcus aureus, opened doors of opportunities for natural products research to explore novel antimicrobial agents. @*Objective@#This study aimed to determine the antimicrobial activity of cell-free supernatants from Lactobacillus plantarum BS25 and Pediococcus acidilactici S3 against Staphylococcus aureus (ATCC# 25923) and methicillin-resistant S. aureus (ATCC# 33591). @*Methodology@#Cell-free supernatants (CFS) of Lactobacillus plantarum BS25 and Pediococcus acidilactici S3, isolated from fermented rice-fish mixture balao-balao and fermented spicy sausage longganisa, respectively, were tested against methicillin-susceptible (MSSA, ATCC 25923) and methicillin-resistant (MRSA, ATCC 33591) Staphylococcus aureus strains for antibacterial activity using the resazurin assay. @*Results@#Both BS25 and S3 CFS showed high activities against MSSA and partial inhibition against MRSA. Proteinaceous components of the CFS were extracted using ammonium sulfate precipitation with BS25 and S3 exhibited low activities against MSSA but partial inhibition was observed against MRSA. Other small molecules were extracted from the CFS through liquid-liquid extraction using ethyl acetate and tested in 100, 250, 500, 750, and 1000 ppm concentrations. The 1000-ppm concentrations of the BS25 and S3 ethyl acetate extracts achieved the highest antibacterial activity against MSSA and MRSA. @*Conclusion@#This study showed that the crude cell-free supernatants, ammonium sulfate precipitates, and ethyl acetate extracts of BS25 and S3 CFS exhibited potential in inhibiting Gram-positive MSSA and MRSA. However, the partially-purified samples require relatively high concentrations in order to produce significant inhibition activities and therefore require further purification.