Prevalence of and risk factors associated with Methicillin-Resistant Staphylococcus aureus(MRSA) carriage among cutting specialties at the Ospital ng Maynila Medical Center

Objective@#To determine the point prevalence of, and risk factors associated with MRSA carriage among resident physicians of surgical departments at the Ospital ng Maynila Medical Center.@*Methods@#Design: Cross-sectional Study. Setting: Tertiary Government Training Hospital. Participants:51 resident physicians from different surgical departments (general surgery, obstetrics and gynecology, ophthalmology, otorhinolaryngology – head and neck surgery and dermatology) underwent nasal and pharyngeal swabs with microbial culture and sensitivity testing to identify MRSA carriers. Fisher Exact Test and logistic regression were utilized to determine associations between MRSA carriage and various risk factors including frequency of hand washing and departmental affiliation.@*Results@#Overall prevalence rate of MRSA carriage was 9.8%. Otorhinolaryngology residents had the highest combined prevalence of MRSA of 42.9%, significantly higher compared to other departments and were used as a reference in logistic regression analyses. Notably, handwashing only once daily was associated with a 20-fold increase in the risk of MRSA carriage (OR 20.5, 95% CI: 1.82 to 230, p = .014). Other departments did not demonstrate statistically significant differences in MRSA carriage rates.@*Conclusions@#Otorhinolaryngology resident physicians had the highest combined prevalence of MRSA and nasal MRSA was found only in otorhinolaryngology residents. The surgical subspecialty and frequency of handwashing of the healthcare worker were identified as important risk factors to develop MRSA carriage. Targeted interventions (including enhanced infection control protocols and regular screening) are needed especially in high-risk departments.

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.

Shock séptico en niños con bacteriemia por Staphylococcus aureus de la comunidad en un hospital pediátrico de alta complejidad / Septic shock in children with community acquired Staphylococcus aureus bacteremia in a high complexity pediatric hospital

INTRODUCCIÓN: La información disponible sobre los factores de riesgo para el desarrollo de shock séptico es escasa, especialmente en población pediátrica. OBJETIVO: Describir las características epidemiológicas y clínicas de los niños con bacteriemia adquirida en la comunidad por Staphylococcus aureus y comparar las características de los pacientes con y sin shock séptico. PACIENTES Y MÉTODOS: Estudio de cohorte retrospectivo. Criterios de inclusión: niños entre 30 días y 16 años de edad, internados en el Hospital de Pediatría Juan P. Garrahan entre enero de 2017 y diciembre de 2019 por infecciones adquiridas en la comunidad con desarrollo de S. aureus en hemocultivos. Criterios de exclusión: antecedente de internación dentro de los 3 meses previos al ingreso, vivir en una comunidad cerrada, presencia de catéter de larga permanencia, dispositivos intraventriculares o intraperitoneales. Análisis estadístico: STATA 16. RESULTADOS: Se incluyeron 142 niños. 21 niños (15%) presentaron shock séptico. En el análisis multivariado, se asociaron con shock séptico, la bacteriemia persistente (OR 7,15; IC95% 4,39-23,81; p: 0,001) y el foco secundario de infección (OR 6,72; IC 95% 2,02-22,2; p 0,002). La mortalidad relacionada con la infección fue 3,5% (5 pacientes). CONCLUSIONES: El shock séptico se asoció con la bacteriemia persistente y la presencia de focos secundarios de infección.

BACKGROUND: Available information about risk factors for the development of septic shock is scarce, especially in the pediatric population. AIM: To describe the epidemiological and clinical characteristics of children with community-acquired Staphylococcus aureus bacteremia and to compare the characteristics of children with and without septic shock. METHODS: Retrospective cohort study. Inclusion criteria: Children between 30 days and 16 years old, hospitalized in the Juan P. Garrahan Pediatric Hospital between January 2017 and December 2019 for community-acquired infections with S. aureus isolation in blood cultures. Exclusion criteria: History of hospitalization within 3 months prior to admission, living in a closed community, presence of long-term catheter, intraventricular or intraperitoneal devices. Statistical analysis: STATA 16. RESULTS: 142 children were included. 21 children (15%) experienced septic shock. On multivariate analysis, persistent bacteremia (OR 7.15, 95% CI 4.39-23.81, p: 0.001) and secondary focus of infection (OR 6.72, 95% CI 2.02-22.2, p 0.002) were associated with septic shock. The infection-related mortality rate was 3.5% (5 patients). CONCLUSIONS: Septic shock was associated with persistent bacteremia and the presence of secondary foci of infection.

Prevalencia de colonización nasal por Staphylococcus aureus meticilino resistente en estudiantes de medicina de la Pontificia Universidad Católica de Chile: comparación entre estudiantes no expuestos a la clínica (pre-clínicos) y clínicos / Prevalence of nasal colonization by methicillin-resistant Staphylococcus aureus in medical students in Chile: comparison between pre-clinical and clinical environment

OBJETIVOS: El objetivo primario de este estudio fue determinar la prevalencia de colonización nasal por Staphylococcus aureus meticilino resistente (SAMR) en estudiantes de medicina en cursos pre-clínicos versus clínicos de la Pontificia Universidad Católica de Chile y describir el patrón epidemiológico, clínico y molecular de las cepas de SAMR obtenidas. PACIENTES Y MÉTODO: Se realizó un estudio descriptivo transversal a 299 estudiantes de pregrado y postgrado de medicina de la Pontificia Universidad Católica de Chile, 44 alumnos de primer año y 29 de segundo año, correspondiendo éstos a alumnos de cursos sin exposición clínica habitual y 26 alumnos de sexto año, 58 de séptimo año y 142 residentes, los cuales están diariamente expuestos a ambientes hospitalarios. RESULTADOS: Se encontró una portación de 0% (0/73) en estudiantes no expuestos a la clínica (cursos pre-clínicos) y de 0,9% (2/226) en estudiantes de cursos clínicos, diferencia que no fue estadísticamente significativa (valor p 0,42). CONCLUSIONES: La portación nasal de SAMR en el personal de salud de este trabajo fue baja, encontrando muestras positivas solo en estudiantes con exposición clínica. Esta prevalencia es similar a la reportada en otros trabajos de características similares realizados en Chile.

OBJECTIVES: The primary objective of this study was to determine the prevalence of nasal colonization of methicillin resistant Staphylococcus aureus (MRSA) in medical students in pre-clinical versus clinical courses at the Pontificia Universidad Católica de Chile and to describe the epidemiological, clinical and molecular pattern of the MRSA strains obtained. METHOD: A cross-sectional descriptive study was carried out on 299 undergraduate and graduate medical students from the Pontificia Universidad Católica de Chile, 44 first-year students and 29 second-year students, corresponding to students of courses without regular clinical exposure and 26 sixth-year students, 58 seventh-year and 142 residents, who are daily exposed to hospital environments. RESULTS: A carriage of 0% (0/73) was found in students not exposed to the clinic (pre-clinical courses) and 0.9% (2/226) in students of clinical courses, a difference that was not statistically significant (p-value 0.42). CONCLUSIONS: The MRSA nasal carriage found in our medical students was low, finding positive samples only in students with clinical exposure. This prevalence is similar to the one reported in other studies in Chile with similar characteristics.

Piomiositis en pediatría: experiencia de 10 años en un hospital pediátrico de alta complejidad en Argentina / Pyomyositis in pediatrics: 10-year experience in a high-complexity pediatric hospital in Argentina

INTRODUCCIÓN: La piomiositis es una infección bacteriana agudasubaguda del músculo esquelético. OBJETIVO: Estimar la incidencia de piomiositis en pacientes internados, describir e identificar factores de riesgo para bacteriemia y hospitalización, y evaluar diferencias entre Staphylococccus aureus sensible y resistente a meticilina (SASM y SARM). PACIENTES Y MÉTODOS: Estudio descriptivo, retrospectivo, observacional, con pacientes de 1 mes a 18 años de edad, internados entre el 1 de enero de 2008 y 31 de diciembre de 2018. Variables: sexo, edad, hacinamiento en el hogar, existencia de lesión previa, estacionalidad, localización anatómica e imágenes, antibioterapia previa, estadio clínico, parámetros de laboratorio, cultivos y antibiograma, días de tratamiento intravenoso (IV), de internación, de fiebre y bacteriemia. RESULTADOS: Se incluyeron 188 pacientes. Incidencia: 38,9 casos / 10.000 admisiones (IC95 % 33,7 - 44,9). Días de internación y tratamiento IV: 11 (RQ 8-15 y RQ 8-14, respectivamente). El desarrollo de bacteriemia se asoció a PCR elevada (p = 0,03) y fiebre prolongada (p < 0,001). No hubo diferencias en la evolución y parámetros de laboratorio entre SASM y SARM. La leucocitosis (p = 0,004), neutrofilia (p = 0,005) y bacteriemia (p = 0,001) se asociaron a mayor estadía hospitalaria. CONCLUSIONES: Este estudio recaba la experiencia de más de 10 años de niños internados con diagnóstico de piomiositis y proporciona información sobre sus características. Se describen parámetros asociados a bacteriemia y estadía hospitalaria.

BACKGROUND: Pyomyositis is an acute-subacute bacterial infection of skeletal muscle. AIM: To estimate the incidence of pyomyositis in hospitalized patients, describe and identify risk factors for bacteremia and hospitalization, and evaluate differences between MSSA and MRSA. METHODS: Descriptive, retrospective, observational study with patients aged 1 month to 18 years hospitalized between January, 1, 2008 and December 1, 2018. Variables: sex, age, home overcrowding, previous injury, seasonality, anatomical location and images, previous antibiotherapy, clinical stage, laboratory, cultures and antibiogram, days of intravenous (IV) treatment, hospitalization, fever and bacteremia. RESULTS: 188 patients were included. Incidence: 38.9 cases/10,000 admissions (95% CI 33.7 - 44.9). Days of hospitalization and IV treatment: 11 (RQ 8-15 and RQ 8-14, respectively). The development of bacteremia was associated with elevated CRP (p = 0.03) and prolonged fever (p < 0.001). There were no differences in the evolution and laboratory parameters between MSSA and MRSA. Leukocytosis (p = 0.004), neutrophilia (p = 0.005), and bacteremia (p = 0.001) were associated with a longer hospital stay. CONCLUSIONS: This study collects the experience of more than 10 years of hospitalized children diagnosed with pyomyositis and provides information on its characteristics. Parameters associated with bacteremia and hospital stay are described.

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 .

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.

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.

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.

The mechanism of berberine on Methicillin resistant Staphylococcus aureus in vitro / 中华预防医学杂志

Objective: To explore the impact of traditional Chinese medicine berberine (BBR) on membrane integrity and permeability of Methicillin-resistant Staphylococcus aureus (MRSA) and the change of bacterial cell wall structure, laying a foundation for the clinical application of berberine in antibacterial. Methods: This study used a non-randomized concurrent controlled trial. The 3 MRSA strains were isolated and cultured from lower respiratory tract samples of geriatric patients from Shanghai Eighth People's Hospital between 2019 and 2020.The Meirier VETEK MS fully automated rapid microbial mass spectrometry detection system and VETEK 2 Compact fully automated microbial identification instrument were used to identify bacterial drug sensitivity experiments to detect bacterial species and drug sensitivity. The minimal inhibitory concentration (MIC) of BBR on MRSA strains was determined by broth microdilution. This study used conductivity tests to assess the changes in membrane permeability in response to different concentration of BBR on MRSA, while also investigating the changes in MRSA morphology by transmission electron microscopy. GraphPad Prism5 was used to analyze the differences in the electrical conductivity experimental results. Results: The MIC of BBR on MRSA was 64 μg/ml. After co-culturing MRSA with BBR for 4 h at 8 μg/ml, 16 μg/ml, 32 μg/ml, 64 μg/ml and 128 μg/ml, respectively, the electrical conductivity increased, compared with the control group, by 24.49%,34.59%,208.92%,196.40% and 208.68%, respectively. By transmission electron microscopy, This study found that low concentration of BBR (8 μg/ml,1/8 MIC) caused no significant damage to MRSA, and the bacterial structure of MRSA remained intact. The cell wall of MRSA became thinner after treatment with berberine at medium concentration (64 μg/ml,1 MIC), while high concentration of BBR (512 μg/ml,8 MIC) induced the destruction and dissolution of MRSA cell wall structure and the leakage of bacterial contents, leading to bacterial lysis. Conclusion: Berberine can kill bacteria by altering the permeability of MRSA cell membrane and destroying and dissolving the structure of the cell wall.

The mechanism of berberine on Methicillin resistant Staphylococcus aureus in vitro / 中华预防医学杂志

Objective: To explore the impact of traditional Chinese medicine berberine (BBR) on membrane integrity and permeability of Methicillin-resistant Staphylococcus aureus (MRSA) and the change of bacterial cell wall structure, laying a foundation for the clinical application of berberine in antibacterial. Methods: This study used a non-randomized concurrent controlled trial. The 3 MRSA strains were isolated and cultured from lower respiratory tract samples of geriatric patients from Shanghai Eighth People's Hospital between 2019 and 2020.The Meirier VETEK MS fully automated rapid microbial mass spectrometry detection system and VETEK 2 Compact fully automated microbial identification instrument were used to identify bacterial drug sensitivity experiments to detect bacterial species and drug sensitivity. The minimal inhibitory concentration (MIC) of BBR on MRSA strains was determined by broth microdilution. This study used conductivity tests to assess the changes in membrane permeability in response to different concentration of BBR on MRSA, while also investigating the changes in MRSA morphology by transmission electron microscopy. GraphPad Prism5 was used to analyze the differences in the electrical conductivity experimental results. Results: The MIC of BBR on MRSA was 64 μg/ml. After co-culturing MRSA with BBR for 4 h at 8 μg/ml, 16 μg/ml, 32 μg/ml, 64 μg/ml and 128 μg/ml, respectively, the electrical conductivity increased, compared with the control group, by 24.49%,34.59%,208.92%,196.40% and 208.68%, respectively. By transmission electron microscopy, This study found that low concentration of BBR (8 μg/ml,1/8 MIC) caused no significant damage to MRSA, and the bacterial structure of MRSA remained intact. The cell wall of MRSA became thinner after treatment with berberine at medium concentration (64 μg/ml,1 MIC), while high concentration of BBR (512 μg/ml,8 MIC) induced the destruction and dissolution of MRSA cell wall structure and the leakage of bacterial contents, leading to bacterial lysis. Conclusion: Berberine can kill bacteria by altering the permeability of MRSA cell membrane and destroying and dissolving the structure of the cell wall.

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.

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.

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)