Molecular differentiation of coagulase-positive staphylococcal isolates carrying mecA- and PVL-encoding genes among healthy males

Aims@#This study was aimed to monitor the asymptomatic carriage of coagulase-positive staphylococcal bacteria among university male students and detect the prevalence of virulence marker genes that encode methicillin resistance (mecA) and Panton-Valentine leukocidin (PVL) toxin among the isolates.@*Methodology and results@#Single nasal swaps were collected from 144 participating students who resided at four different locations within Al-Madinah city. A total of 112 Gram-positive staphylococcal isolates were recovered from the 144 participants (carriage rate of 77.8%). Coagulase-positive staphylococci were differentiated using duplex PCR amplification of the 16S rRNA and nuc genes and accounted for 30 isolates (carriage rate of 20.8%). These isolates were most prevalent in the northern and southern parts of Al-Madinah city, while the lowest numbers of isolates were detected in students of the eastern part. Coagulase-positive isolates were further phenotypically characterized for methicillin resistance by the disc diffusion method. Uniplex PCR assays were conducted to screen for mecA- and PVL toxin-encoding genes. The mecA gene was amplified from all 15 (50%) methicillin-resistant coagulase-positive isolates, while the PVL toxin-encoding gene was detected in 19 isolates (63.3%), 10 (33.3%) of which contained the mecA gene. Lastly, PCR amplification of the NRPS gene from coagulase-positive isolates revealed the absence of Staphylococcus argenteus, the recently discovered genetically divergent lineage of Staphylococcus aureus.@*Conclusion, significance and impact of study@#An elevated prevalence of coagulase-positive isolates harboring mecA and PVL virulence genes was observed compared with previous investigations. This poses a potential threat if they spread among the population, resulting in outbreaks of community-acquired infections.

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.

Repositioning of FDA-approved drugs for the treatment of methicillin-resistant Staphylococcus aureus infection: Structure-based virtual screening and in vitro assay

Background: Computer-aided repositioning of approved drugs is an increasingly popular strategy for the discovery of effective therapies. The potency of the newly repositioned drugs can be optimized using them as a component of an effective drug combination, thereby achieving the desired therapeutic effect at a lower and more tolerable drug concentration. Aim and Objectives: The aim of the study was to perform structure-based virtual screening and repurposing of FDA-approved drugs for the treatment of methicillin resistance by Staphylococcus aureus (SA) and perform an in vitro validation of the prediction. Materials and Methods: Following ethical clearance at the Department of Pharmacology and Therapeutics, College of Health Sciences, Usmanu Danfodiyo University Sokoto, molecular docking was performed against 5 validated protein targets involved in the development of methicillin resistance by SA and an in vitro validation of the prediction was done using 3 of the top-ranking drug candidates against methicillin-resistant vancomycin-susceptible strain of the pathogen (ATCC 43300). Results: Desmopressin and docetaxel, two of the 20 top-ranking repurposed drugs discovered through virtual screening, enhanced the inhibitory effect of oxacillin against the ATCC 43300 SA strain in a ratio-dependent manner, although each of the two drugs singly was only weakly effective against the bacterial strain. The standard drug, vancomycin (also among the top-scoring candidates), alone, was effective against ATCC 43300 strain and in combination with oxacillin, the two drugs produced a ratio-dependent synergistic effect against the bacterial strain. Conclusion: These findings suggest that oxacillin-based combinations with desmopressin, docetaxel, and the standard drug vancomycin, three of the 20 top-ranking drugs, at optimum ratios, may be beneficial in reversing the resistance of the ATCC 43300 SA strain to oxacillin, thus supporting the prediction of the molecular docking results.

Antibiotic Susceptibility, Carrier State and Predictors of Outcome of Staphylococcus aureus Infections in Hospitalized Children

Objectives: To evaluate the antibiotic resistance pattern, clinical profile and predictors for adverse outcomes in children hospitalized due to staphylococcal infection; and the frequency of nasal and axillary carrier states in these children. Methods: This descriptive study enrolled 100 symptomatic children (aged 1 month - 12 years) in whom S. aureus was isolated from cultures of blood, pus or cerebrospinal fluid. All samples were processed as per the Clinical and Laboratory Standards Institute (CLSI) standards. Antimicrobial susceptibility was tested using disc diffusion method; minimum inhibitory concentration (MIC) for vancomycin was measured using E strips. Predictors for poor recovery were determined by univariate and multivariable logistic regression analysis. Results: Skin and soft tissue infections were the most common (47%) followed by respiratory infections (37%). Methicillin-resistant Staphylococcus aureus (MRSA) was detected in 62%, out of which 63% (39/62) were multi-drug resistant. Carrier state was present in 49% (93% MRSA); 80% were axillary carriers. High MIC (>1 µg/mL) for vancomycin was seen in 65% of patients, and was the only factor associated with poor recovery [aOR (95%CI) 5.3 (1.6,18.5); P=0.008] on multivariable logistic regression analysis. Conclusion: MRSA is the predominant strain in severe staphylococcal infections requiring hospitalization, and majority of them are multidrug resistant. High MIC to vancomycin among S. aureus is an emerging concern.

Prevalence and Susceptibility of Staphylococcus aureus Nasal Carriage Strains Isolated from Haemodialysis Patients

@#Introduction: Staphylococcus aureus is part of the normal human flora that can commonly be found on the skin and mucous membranes of the nasal area. However, in immunosuppressed patients such as those with kidney failures, colonization can potentially lead to infection. There is a concern of increasing antibiotic resistance in S. aureus. This study aimed to determine the prevalence of S. aureus nasal colonization and its antimicrobial susceptibility among haemodialysis-dependent populations. Methods: A cross-sectional study at the Nephrology Unit, Hospital Canselori Tuanku Mukhriz (HCTM) was conducted among haemodialysis-dependent patients between February 2017 to February 2018. Nasal swabs were obtained and cultured on mannitol salt agar. S. aureus isolates were identified by gram staining, tube coagulase and Deoxyribonuclease (DNase). Cefoxitin disc (30 µg) were used to identified the presence of MRSA (methicillin-resistance S. aureus). The S. aureus colonies were further tested against six antibiotics using Kirby Bauer disc diffusion. Result: A total of 134 patients were recruited. S. aureus isolates were detected from 27 patients (20.1%). All S. aureus were phenotypically identified as methicillin-sensitive S. aureus (MSSA) based on the cefoxitin disc. Teicoplanin and linezolid were the most effective with 100% susceptibility. S. aureus exhibited a high resistance rate towards erythromycin (29.6%). No MRSA was isolated in this study. Conclusion: This study highlighted the high prevalence of S. aureus nasal colonization in haemodialysis patients. Teicoplanin and linezolid were found to be the most effective antibiotics against isolated S. aureus.

Antibacterial activity of plant essential oils against indigenously characterized methicillin-resistant Staphylococcus aureus (MRSA)

@#Plant essential oils were evaluated for antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA). The isolates (n=03) were procured from Institute of Microbiology, UVAS Lahore, Pakistan. After biochemical and 16S rRNA gene-based PCR characterization, accession numbers were retrieved from NCBI i.e. MW344063.1, MW344064.1 and MW344065.1. These isolates exhibited molecular positivity by multiplex PCR for mecA, coa and eta toxin genes. Moreover, these isolates exhibited resistance to cefoxitin, ampicillin, amoxicillin, penicillin, amoxicillin clavulanate, ciprofloxacin, erythromycin and gentamicin. The antibiotic resistant isolates were evaluated for antimicrobial activity of plant essential oils. The highest zone of inhibition (mean ZOI±S.D.) was measured for Cinnamomum verum (22.67±1.52 mm) followed by Eucalyptus globulus (18.67±2.51 mm) and Syzygium aromaticum (12.67±2.51 mm). Lowest mean MIC value (0.33±0.11 mg/mL) was recorded for E. globulus. Eucalyptus globulus was processed for fractionation by column chromatography and n-hexane, chloroform, n-hexane + chloroform and ethyl-acetate fractions were evaluated for antibacterial activity. Lowest mean MIC (10.04±5.80 mg/mL) was recorded for E. globulus n-hexane fraction. Cell survival percentage of BHK21 cell line was 51.7% at 54.87mg/mL concentration of E. globulus n-hexane fraction. Through gas chromatography-mass spectrometry (GC-MS) analysis of n-hexane fraction, benzene was found abundant (29.9%) as active compound. It was concluded that E. globulus n-hexane fraction exhibited significantly promising results against MRSA.

Antibiotic resistance patterns of methicillin-resistant coagulase negative staphylococci isolated from blood cultures at a university hospital in Turkey

Aims@#Recent reports indicate that many coagulase-negative staphylococci (CoNS) strains are resistant to most antimicrobials used against staphylococcal infections. This study was aimed to determine the species distribution of the CoNS isolates in Lokman Hekim Ankara Hospital and determine their antimicrobial resistance characteristics.@*Methodology and results@#The study was conducted at Lokman Hekim University Ankara Hospital between February 2020 and August 2021. The 154 blood cultures included in the study were incubated in the BACTEC FX40 automated blood culture device. Identification and antimicrobial susceptibility tests of the samples with positive catalase tests were performed with the BD Phoenix Automated Microbiology Sensitivity System. The statistical significance level was accepted as p<0.05. Nineteen different types of methicillin-resistant coagulase-negative staphylococci (MRCoNS) isolated from different age groups were identified. Vancomycin resistance was observed in 20 samples (13%). Trimethoprim-sulfamethoxazole (TMP-SMX) resistance was seen in 44 of 152 samples (28.6%), linezolid resistance in 15 of 143 samples (10.5%) and daptomycin resistance in 16 of 146 blood samples (11%).@*Conclusion, significance and impact of study@#In our investigation, there has been a striking rise in the prevalence of vancomycin, TMP-SMX, linezolid and daptomycin resistance among infections with the MRCoNS. Identifying and classifying multidrug resistance on MRCoNS requires reliable epidemiological data to be collected and compared between healthcare facilities in different countries. The research finding reported in this paper will contribute to the determination of alternative antibiotics for treating MRCoNS.

Genomic characterization, antimicrobial resistance profiles, enterotoxin, and biofilm production of methicillin-resistant Staphylococcus aureus isolated from clinical and animal products origins in Eastern Turkey

ABSTRACT: Staphylococcus aureus is an opportunistic and ubiquitous pathogen found in the skin, nares, and mucosal membranes of mammals. Increasing resistance to antimicrobials including methicillin has become an important public concern. One hundred and eight (108) S. aureus strains isolated from a total of 572 clinical and animal products samples, were investigated for their biofilm capability, methicillin resistance, enterotoxin genes, and genetic diversity. Although only one strain isolated from raw retail was found as a strong biofilm producer, the percentage of antimicrobial resistance pattern was relatively higher. 17.59% of S. aureus strains tested in this study were resistant to cefoxitin and identified as methicillin-resistant S. aureus (MRSA) isolates. mecA and mecC harboring S. aureus strains were detected at a rate of 2.79% and 0.93%, respectively. In addition, staphylococcal enterotoxin genes including Sea, Seb, Sec, and Sed genes were found to be 18.5%, 32.4%, 6.5% and 3.7%, respectively. The phylogenetic relationship among the isolates showed relationship between joint calf and cow milk isolates. Multi locus sequence typing (MLST) revealed three different sequence types (STs) including ST84, ST829, and ST6238. These findings highlight the development and spread of MRSA strains with zoonotic potential in animals and the food chain throughout the world.

RESUMO: Staphylococcus aureus é um patógeno dúctil e ubíquo encontrado na pele, narinas e membranas mucosas de mamíferos. O aumento da resistência aos antimicrobianos, incluindo a meticilina, tornou-se uma importante preocupação pública. Cento e oito (108) cepas de S. aureus isoladas de um total de 572 amostras clínicas e de produtos animais foram investigadas por sua capacidade de biofilme, resistência à meticilina, genes de enterotoxinas e diversidade genética. Embora apenas uma cepa isolada do cru tenha sido encontrada como forte produtora de biofilme, a porcentagem do padrão de resistência antimicrobiana foi relativamente maior. Parte das cepas (17,59%) de S. aureus testadas neste estudo eram resistentes à cefoxitina e identificadas como isolados de MRSA. mecA e mecC abrigando cepas de S. aureus foram detectados a uma taxa de 2,79% e 0,93%, respectivamente. Além disso, verificou-se que os genes da enterotoxina estafilocócica, incluindo os genes Sea, Seb, Sec e Sed, eram 18,5%, 32,4%, 6,5% e 3,7%, respectivamente. A relação filogenética entre os isolados mostrou relação entre os isolados de bezerro e leite de vaca. A tipagem de sequência multiloco (MLST) revelou três tipos de sequência diferentes (STs), incluindo ST84, ST829 e ST6238. Essas descobertas destacam o desenvolvimento e a disseminação de cepas de MRSA com potencial zoonótico em animais e na cadeia alimentar em todo o mundo.

Genomic characterization, antimicrobial resistance profiles, enterotoxin, and biofilm production of methicillin-resistant Staphylococcus aureus isolated from clinical and animal products origins in Eastern Turkey / Caracterização genômica perfis de resistência antimicrobiana, produção de enterotoxinas e biofilme Staphylococcus aureus resistente à meticilina isolado de origem clínica e de produtos de origem animal no leste da Turquia

Staphylococcus aureus is an opportunistic and ubiquitous pathogen found in the skin, nares, and mucosal membranes of mammals. Increasing resistance to antimicrobials including methicillin has become an important public concern. One hundred and eight (108) S. aureus strains isolated from a total of 572 clinical and animal products samples, were investigated for their biofilm capability, methicillin resistance, enterotoxin genes, and genetic diversity. Although only one strain isolated from raw retail was found as a strong biofilm producer, the percentage of antimicrobial resistance pattern was relatively higher. 17.59% of S. aureus strains tested in this study were resistant to cefoxitin and identified as methicillin-resistant S. aureus (MRSA) isolates. mecA and mecC harboring S. aureus strains were detected at a rate of 2.79% and 0.93%, respectively. In addition, staphylococcal enterotoxin genes including Sea, Seb, Sec, and Sed genes were found to be 18.5%, 32.4%, 6.5% and 3.7%, respectively. The phylogenetic relationship among the isolates showed relationship between joint calf and cow milk isolates. Multi locus sequence typing (MLST) revealed three different sequence types (STs) including ST84, ST829, and ST6238. These findings highlight the development and spread of MRSA strains with zoonotic potential in animals and the food chain throughout the world.

Staphylococcus aureus é um patógeno dúctil e ubíquo encontrado na pele, narinas e membranas mucosas de mamíferos. O aumento da resistência aos antimicrobianos, incluindo a meticilina, tornou-se uma importante preocupação pública. Cento e oito (108) cepas de S. aureus isoladas de um total de 572 amostras clínicas e de produtos animais foram investigadas por sua capacidade de biofilme, resistência à meticilina, genes de enterotoxinas e diversidade genética. Embora apenas uma cepa isolada do cru tenha sido encontrada como forte produtora de biofilme, a porcentagem do padrão de resistência antimicrobiana foi relativamente maior. Parte das cepas (17,59%) de S. aureus testadas neste estudo eram resistentes à cefoxitina e identificadas como isolados de MRSA. mecA e mecC abrigando cepas de S. aureus foram detectados a uma taxa de 2,79% e 0,93%, respectivamente. Além disso, verificou-se que os genes da enterotoxina estafilocócica, incluindo os genes Sea, Seb, Sec e Sed, eram 18,5%, 32,4%, 6,5% e 3,7%, respectivamente. A relação filogenética entre os isolados mostrou relação entre os isolados de bezerro e leite de vaca. A tipagem de sequência multiloco (MLST) revelou três tipos de sequência diferentes (STs), incluindo ST84, ST829 e ST6238. Essas descobertas destacam o desenvolvimento e a disseminação de cepas de MRSA com potencial zoonótico em animais e na cadeia alimentar em todo o mundo.

Colonization of methicillin-resistant Staphylococcus aureus among healthcare students: an integrative review

ABSTRACT BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infection is a worldwide concern given its presence even in non-hospitalized healthy individuals, such as university students. OBJECTIVE: To identify in the literature the prevalence of colonization by MRSA among healthcare students. DESIGN AND SETTING: Integrative review of the literature conducted in Universidade Federal do Piauí. METHOD: A search for primary studies was performed in the following databases: Medical Literature Analysis and Retrieval System on-line; Cumulative Index to Nursing and Allied Health Literature; Web of Science; Scopus; and LILACS. RESULTS: This review included 27 studies that demonstrated MRSA infection prevalence ranging from 0.0 to 15.3% among students. CONCLUSION: The prevalence of colonization of MRSA among healthcare students is high, and the nasal cavity was cited as an important reservoir location for these microorganisms.

Assessment of Pathogenicity of Community-Acquired MRSA Isolates in Mice-Induced Peritonitis

@#Introduction: Methicillin-Resistance Staphylococcus aureus (MRSA) is known as a major nosocomial pathogen in healthcare. However, it has now spread in the community known as community-acquired MRSA (CA-MRSA). Thus, the survival and pathogenicity of CA-MRSA isolates were assessed using in vivo peritonitis model with comparison to ATCC-MRSA. Two CA-MRSA isolates; CA-MRSA1 and CA-MRSA2 that were isolated from healthy population, were studied and compared. Methods: Mice were assigned into 4 groups and injected intraperitoneally with ATCC-MRSA, CA-MRSA1 or CA-MRSA2, respectively. Sterile Dulbecco’s Phosphate-Buffered Saline (DPBS) represents negative control. Mice were observed twice daily, 0-72 hours of post-infection. Any signs of distress were recorded for severity score and survival analyses. Mice were euthanised at 72 hours post-inoculation or by referring to the Peritonitis Severity Scoring (PSS) system. Organs of interest, peritoneal lavage and abscess were processed for bacterial counts. Tissue samples were analysed for histopathological scores. Results: All mice inoculated with MRSA showed clear signs of illness with peritonitis symptoms of p<0.001 and comparable PSS scores were recorded in all infected mice groups. Intraperitoneal injection of lethal dose of MRSA resulted in significant death of ATCC-MRSA (p<0.05) and CA-MRSA-infected mice (p<0.01), compared to the un-infected. Bacterial burden was significantly high in all samples harvested from mice challenged with CA-MRSA2 compared to ATCC-MRSA except in abscess and lung. Significant liver necrosis and spleen inflammation were observed in CA-MRSA1, and lung inflammation in ATCC-MRSA-infected mice. Conclusion: Nasal carriage CA-MRSA isolates from a healthy population has the potential to cause peritonitis with comparable severity as ATCC-MRSA.

Staphylococcal cassette chromosome mec elements from Staphylococcus intermedius group (SIG) isolates from dogs in a center for veterinary diagnostics in Brazil / Cassetes cromossômicos estafilocócicos mec de isolados do grupo Staphylococcus intermedius (GSI) de cães em um centro veterinário de diagnósticos no Brasil

ABSTRACT: Methicillin resistance in the Staphylococcus intermedius group (SIG) has emerged in small animal practice. Methicillin-resistant SIG (MRSIG) members have been implicated as causes of infections in both companion animals and humans. Staphylococcal cassette chromosome mec (SCCmec) elements carry the mecA/C genes, which encode for the transpeptidase PBP2a (PBP2') responsible for β-lactam antibiotic resistance in staphylococci. This study examined the SCCmec types of MRSIG isolates from different clinical specimens of dogs that exhibited methicillin MIC ≥ 0.5 μg/mL by an automated identification and susceptibility system in a Center for Veterinary Diagnostics in São Paulo, Brazil. Susceptibility to methicillin was determined by broth microdilution testing, and Oxoid® M.I.C.Evaluator® strips. PBP2a production was detected using a latex agglutination assay. SCCmec typing was performed according to the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) guidelines. SCCmec type II (2A), SCCmec type III (3A), composite SCC structures consisting of a class A mec gene complex in addition to multiple ccr gene complexes, and non-typable SCCmec elements were reported in these MRSIG isolates. SCCmec type variants differing from those so far acknowledged by IWG-SCC were found, indicating new rearrangements in the genetic context of mecA in these canine MRSIG isolates.

RESUMO: A resistência à meticilina no grupo Staphylococcus intermedius (GSI) tem aumentado na clínica de pequenos animais. Membros GSI resistentes à meticilina (GSIRM) têm sido causas de infecções tanto em animais de companhia e humanos. Cassetes cromossômicos estafilocócicos mec (SCCmec) carregam os genes mecA/C, que codificam a transpeptidase PBP2a (PBP2') responsável pela resistência aos antibióticos β-lactâmicos em estafilococos. Nosso objetivo foi investigar os elementos SCCmec de GSIRM isolados de diferentes amostras clínicas de cães que exibiram CIM de meticilina ≥ 0,5 μg/mL por meio de um sistema automatizado em um Centro Veterinário de Diagnósticos em São Paulo, Brasil. A sensibilidade à meticilina foi determinada por meio do teste de microdiluição em caldo e fitas Oxoid® M.I.C.Evaluator®. A produção de PBP2a foi detectada usando um ensaio de aglutinação de látex. A tipagem dos elementos SCCmec foi realizada de acordo com as diretrizes do International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC). SCCmec tipo II (2A), SCCmec tipo III (3A), SCC compostos de um complexo mec de classe A com múltiplos complexos ccr, e elementos SCCmec não tipáveis foram encontrados nesses isolados GSIRM. Variantes que diferem dos elementos SCCmec reconhecidos até o momento pelo IWG-SCC foram encontradas, indicando novos rearranjos no contexto genético de mecA nesses isolados GSIRM caninos.

Índice de contaminação por ORSA em superfícies de uma enfermaria de Infectologia em Vitória, ES / ORSA contamination index in surfaces of an Infectology nursing in Vitória, ES

Objetivo: Avaliar a presença de Staphylococcus aureus resistente à oxacilina (ORSA) em superfícies frequentemente tocadas pelas mãos dos pacientes e profissionais de saúde (unidades de amostragem: maçanetas de portas e grades laterais dos leitos) antes e depois de limpeza concorrente em dias de semana e no final de semana. Método: Trata-se de estudo transversal de abordagem qualitativa, realizado na enfermaria de Infectologia de um Hospital Universitário de Vitória, ES. A qualidade da desinfecção foi avaliada por meio de cultivo qualitativa de S. aureus em uma área delimitada dos locais de coleta antes e após a limpeza concorrente. Posteriormente foi avaliado por meio de teste de disco-difusão o perfil de susceptibilidade das linhagens de S. aureus frente à oxacilina. As variáveis estudadas foram presença da bactéria e perfil de susceptibilidade (antibiograma). Resultados: Foram coletadas 93 amostras, sendo 37 (39,78%) em grades de leitos e 56 (60,22%) em maçanetas com proporção de dias de semana e final de semana semelhantes. Das 93 amostras, vinte (21,51%) foram positivas para S. aureus. Destas, quatro (20%) foram identificadas como ORSA. Conclusão: A análise estatística por meio do teste de Fisher revelou que não existe associação entre a qualidade, antes e depois, da limpeza. A análise entre os dias de coleta, final de semana e dias de semana, revelou que há independência entre as variáveis, corroborando a presença de um padrão de limpeza, independente do dia da semana.

Objective: To evaluate the presence of oxacillin-resistant Staphylococcus aureus (ORSA) on surfaces frequently touched by the hands of patients and healthcare professionals (sampling units: door handles and bed side rails) before and after concurrent cleaning on weekdays and at the weekend. Methods: This is a cross-sectional study with a qualitative approach, carried out in the Infectious Diseases of a University Hospital in Vitória, ES. The quality of disinfection was assessed by means of qualitative cultivation of S. aureus in a defined area of the collection sites before and after concurrent cleaning. Subsequently, the susceptibility profile of S. aureus strains against oxacillin was evaluated by means of a disk-diffusion test. The variables studied were the presence of the bacterium and susceptibility profile (antibiogram). Results: 93 samples were collected, 37 (39.78%) in bed racks and 56 (60.22%) on door handles with a similar proportion of weekdays and weekends. Of the 93 samples, twenty (21.51%) were positive for S. aureus. Of these, four (20%) were identified as ORSA. Conclusion: Statistical analysis using Fisher's test revealed that there is no association between the quality, before and after, of cleaning. The analysis between the collection days, weekends and weekdays, revealed that there is independence between the variables, corroborating the presence of a cleaning pattern, regardless of the day of the week.

Estandarización del análisis multi-locus de número variable de repeticiones en tándem automatizado para tipificación de Staphylococcus aureus Resistentes a Meticilina causantes de infecciones invasivas en población pediátrica paraguaya / Standardization of automated multi-locus variable number tandem repeats analysis for Methicillin-resistant Staphylococcus aureus typing isolated from invasive infections in paraguayan pediatric population

Introducción: Staphylococcus aureus es considerado uno de los patógenos humanos más importantes a nivel mundial y sus niveles de resistencia a meticilina han aumentado incluso en cepas aisladas de personas sin factores de riesgo nosocomial, por lo que la tipificación genética de los clones circulantes es fundamental para comprender los patrones de diseminación. Objetivo: Obtener la tipificación de SARM que causaron infecciones invasivas a niños mediante el empleo de la técnica de análisis multi-locus de número variable de repeticiones en tándem (MLVA) automatizada. Materiales y Métodos: Estudio observacional, descriptivo de corte transverso. Resultados: Se analizaron 25 cepas SARM que representan más de 700 aislamientos de S. aureus colectados en los años 2010, 2012 y 2013 de 4 hospitales de referencia nacional. La automatización de la técnica MLVA incluyó la tipificación del 88% (22/25) de los aislamientos en estudio, resultando 3 perfiles diferentes, cada uno asociado a un "spa tipo" distinto, siendo el perfil 1-t019 el predominante (86%), seguido por el perfil 3-t002 (9%), arrojando 100% de concordancia con el método MLVA manual, así como una alta concordancia con el método estándar de oro, PFGE. Conclusiones: La inclusión de un método de análisis de fragmentos automatizado permitió llevar a cabo la caracterización de aislamientos mejorando el tiempo de respuesta y manteniendo una alta sensibilidad en comparación con el método manual.

Introduction: Staphylococcus aureusis considered one of the most critical human pathogens worldwide, and its levels of methicillin resistance have increased even in strains isolated from people without nosocomial risk factors. Therefore the genetic typing of circulating clones is essential to understand dissemination patterns. Objective: Obtain the MRSA typing that caused invasive infections in children by using the automated multi-locus variable number of tandem repeats (MLVA) analysis technique. Materials and methods: Observational, descriptive, cross-sectional. Results: 25 strains MRSA representing more than 700S. aureusisolates collected in 2010, 2012, and 2013 from 4 national reference hospitals were analyzed. The MLVA automation included the typing of 88% (22/25) isolates, resulting in 3 different profiles, each one associated with a different spa type, being the 1-t019 the predominant (86%), followed by the 3-t002 profile (9%), yielding 100% concordance with the MLVA manual, as well as high concordance with the standard gold method, PFGE. Conclusions: The inclusion of an automated fragment analysis method led to the characterization of isolates, improving response time, and maintaining high sensitivity compared to the manual process.

Antibiotic resistance profile in intrahospital pediatric services at third level centers in Dominican Republic / Perfil de resistencia a antibióticos en servicios pediátricos intrahospitalarios en centros de tercer nivel en República Dominicana

Objectives: The Dominican Republic lacks reliable information on antimicrobial resistance (AMR), which would allow physicians to prescribe the best treatment for common infectious diseases. This study aimed to define the antimicrobial resistance profiles of the more common pathogens from pediatric services, where data is even more important due to the vulnerability of the population. Methods: We collected data from patients admitted in the pediatric unit of three third level hospitals in the city of Santiago de los Caballeros, Dominican Republic, showing positive bacterial cultures, during a period of two years. Results: Half of the Gram negative pathogens exhibited third generation cephalosporins (3GC) resistance, 17% were resistant to carbapenems. Serratia marcescens presented an exceptionally high proportion of resistance to 3GC (95.9%). Staphylococcus aureus showed elevated resistance to methicillin (58.4%) and even to clindamycin (35.8%). Conclusion: There are elevated levels of antimicrobial resistance among the Enterobacteriaceae family and the Staphylococcus genus isolated from the pediatric population. Necessary measures should be taken to tackle AMR in the country.

Objetivos: La República Dominicana carece de información confiable sobre las resistencias antimicrobianas en el país, lo que permitiría al personal médico prescribir los mejores tratamientos para infecciones comunes. El objetivo de este estudio es definir los perfiles de resistencia antimicrobiana de los patógenos más comunes en servicios pediátricos, donde esta información es esencial, debido a la vulnerabilidad de la población. Métodos: Se tomaron los datos de reportes microbiológicos con cultivo bacteriano positivo procedentes de pacientes admitidos en la unidad pediátrica de tres hospitales de tercer nivel en la ciudad de Santiago de los Caballeros, República Dominicana, durante un periodo de dos años. Resultados: La mitad de los patógenos Gram negativos mostraron resistencia a cefalosporinas de tercera generación (3GC), 17% eran resistentes a carbapenémicos. Serratia marcescens presentó una resistencia excepcionalmente elevada a 3GC (95.9%). Staphylococcus aureus mostró alta resistencia a meticilina (58.4%) e incluso a clindamicina (35.8%). Conclusión: Existen elevados niveles de resistencia antimicrobiana entre las enterobacterias y los estafilococos en la población pediátrica dominicana. Es necesario tomar medidas para abordar este problema en el país.

Prevalencia y caracterización genotípica de cepas de Staphylococcus aureus resistente a meticilina aisladas en un hospital regional mexicano / Prevalence and genotypic characterization of methicillin-resistant strains of Staphylococcus aureus isolated in a Mexican regional hospital

Resumen Introducción: Staphylococcus aureus es uno de los patógenos con mayor prevalencia en el mundo, asociado a una alta tasa de mortalidad y un rápido desarrollo de resistencia a los antimicrobianos. A pesar de su patogenicidad, su seguimiento epidemiológico en México es escaso. Objetivo: Analizar la epidemiología molecular local y determinar el origen clonal de cepas resistentes a meticilina (RM) aisladas de pacientes internados en el Hospital Central "Dr. Ignacio Morones Prieto". Métodos: Se llevó a cabo un estudio prospectivo de corte transversal, de julio a diciembre de 2016. La caracterización de las cepas se realizó mediante genotipificación Spa, la determinación por RPC punto final de la frecuencia de genes de virulencia específicos y su antibiograma. Resultados: A partir de estos datos, se obtuvo que la prevalencia de S. aureus RM fue de 25,7%, destacando la presencia del tipo Spa t895 en 76% de las cepas resistentes y un patrón similar de susceptibilidad a antimicrobianos. Conclusión: Los resultados de este estudio indican que la prevalencia regional de SARM no se ha modificado en los últimos 10 años y proporcionan información valiosa del origen clonal y los factores de virulencia de las cepas de S. aureus aisladas en la región.

Abstract Background: Staphylococcus aureus is one of most prevalent pathogens in the world associated with a high mortality rate and a rapid development of resistance to antibiotics. Despite its pathogenicity, epidemiological monitoring in Mexico is scarce. Aim: To analyze the local molecular epidemiology and determine the clonal origin of methicillin-resistant (MR) strains isolated from patients admitted to Hospital "Dr. Ignacio Morones Prieto". Methods: A cross-sectional prospective study was carried out from July to December 2016. The characterization of the strains was carried out by Spa genotyping, frequency of specific virulence genes by PCR and antibiogram. Results: The prevalence of MRSA was 25.7%, highlighting the presence of the Spa type t895 in 76% of the resistant strains and a similar pattern of susceptibility to antibiotics. Conclusion: The results of this study indicate that the regional prevalence of MRSA has not changed in the last 10 years and provide valuable information on the clonal origin and the virulence factors of the strains of S. aureus isolated in the region.

Contamination prevalence and drug resistance spectrum of MRSA from classrooms in Guangzhou primary schools / 中国学校卫生

Objective@#To investigate the distribution and drug resistance situation of staphylococcus aureus (SA) and methicillin-resistant staphylococcus aureus (MRSA) from the classroom environments in primary schools of Guangzhou.@*Methods@#The air and the surfaces of door handles, desks, chairs, light switches and floor were sampled in the classrooms of 8 primary schools selected through stratified clustering method in Guangzhou from May to June, 2016. SA and MRSA were isolated and identified, and drug sensitivity tests were conducted.@*Results@#A total of 760 samples were collected, the detection rate of SA and MRSA were 8.8% and 4.2%, respectively. There were statistically significant differences in the detection rate of staphylococcus aureus among different sampling sites(P<0.01).Detection of SA and MRSA on the floor,light’s witches and surface of deskes was both above 6.0%. The multiple drug resistance rate of MRSA was up to 100.0%, and the main resistance mode was Penicillin-Erythromycin-Rifampin-Tetracycline-Teicolanin.@*Conclusion@#MRSA can be detected in air, door handles, desk surface, chair surface, light switch and floor of primary schools. Relevant administration departments should pay attention to the environments health of Guangzhou primary schools.

Identification and characterization of methicillin-resistant Staphylococcus spp. isolated from surfaces near patients in an intensive care unit of a hospital in southeastern Brazil

Abstract INTRODUCTION: Contaminated hospital environments contribute to the transmission of microorganisms associated with healthcare. Contaminated surfaces handled by patients or healthcare professionals are a source of microorganism transmission by hand. Methicillin-resistant Staphylococcus bacteria are among the main agents responsible for increasing healthcare-associated infections in Brazil and worldwide. METHODS: The objective of this study was to screen and characterize methicillin-resistant Staphylococcus spp. on surfaces near patients in an intensive care unit. Microbiological samples, collected from ten beds in an intensive care unit with five sampling sites, were inoculated into a methicillin-resistant Staphylococcus aureus chromogenic medium. MALDI-TOF and PCR analyses were used to identify the bacteria. Antimicrobial susceptibility was determined using the disk diffusion test. The presence of the mecA gene was investigated using PCR. RESULTS: We observed that 44 out of the 50 sampling sites presented grown isolates in the methicillin-resistant Staphylococcus aureus medium. The incidence of isolated microorganisms on the right side rail, left side rail, tables, infusion pump keypad, and cardiac monitor were 18.8 %, 36.7 %, 10.9 %, 2.4 %, and 31 %, respectively. The 42 isolates included in this study were identified as coagulase-negative Staphylococcus. All of these microorganisms were multidrug-resistant and mecA gene-positive. CONCLUSIONS: This study identified the presence of methicillin-resistant coagulase-negative Staphylococcus on the beds of an intensive care unit, providing evidence for the necessity of assertive actions to decrease the risk of healthcare-associated infections at the site.

Case report of a child with influenza and fatal community-associated methicillin-resistant Staphylococcus aureus sepsis

Abstract In the present study, we report the incidence of septic shock syndrome associated with methicillin-resistant Staphylococcus aureus in a child who initially presented influenza-like illness and developed septic shock shortly after 48 h of hospitalization, and eventually died within a few hours of the onset of sepsis. S. aureus isolated from the blood culture was characterized as the community-associated strain carrying the staphylococcal cassette chromosome mec (SCCmec) type IV element. Therefore, it is important to better understand the community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections and their potential association with influenza for early diagnosis and successful treatment of this fatal disease.

Frecuencia y susceptibilidad a penicilina y meticilina de aislamientos ambientales de Staphylococcus aureus en un hospital de Cuenca / Frequency and susceptibility to penicillin and methicillin of Staphylococcus aureus environmental isolations at a Cuenca´s hospital

Staphylococcus aureus es un patógeno asociado con infecciones intrahospitalarias comúnmente hallado en las fosas nasales y las manos del personal de salud; así como, en superficies ambientales, las cuales se convierten en potenciales reservorios y vehículos de transmisión de infecciones. En este estudio se analizó la frecuencia y la susceptibilidad a penicilina y meticilina de aislamientos ambientales de S. aureus en un hospital de Cuenca. Se recolectaron 50 muestras (30 de dos quirófanos y 20 de la sala de cuidados intensivos). S. aureus se identificó por pruebas fenotípicas y detección molecular del gen nuc. La susceptibilidad a meticilina y penicilina se determinó por el método de difusión del disco en agar y los genes blaZ y mecA por reacción en cadena de la polimerasa. La frecuencia de S. aureus fue de 6% (3/50 cepas). La resistencia a penicilina y meticilina fue de 66,6% (2/3 cepas). Los genes blaZ y mecA se detectaron en las dos cepas resistentes a penicilina y meticilina. La baja frecuencia de S. aureus puede estar relacionada con los ambientes analizados; ya que, las superficies muestreadas son áreas donde se hace énfasis en la aplicación de protocolos de higiene y desinfección para asegurar una adecuada descontaminación

Staphylococcus aureus is a pathogen associated with intrahospital infections commonly found in the nasal cavities and the hands of health personnel, as well as, on environmental surfaces; which become potential reservoirs and transmission vehicles of infections. In this study the frequency and susceptibility to penicillin and methicillin of environmental isolates of S. aureus in a hospital to Cuenca were analyzed. 50 samples (30 of two operating room and 20 of the intensive care room) were collected. S. aureus was identified by phenotypic tests and molecular detection of the nuc gene. The susceptibility to methicillin and penicillin was determined by agar disc diffusion method and the blaZ and mecA genes by polymerase chain reaction. The frequency of S. aureus was 6% (3/50 strains). Resistance to penicillin and methicillin was 66.6% (2/3 strains). The blaZ and mecA genes were detected in the two strains resistant to penicillin and methicillin. The low frequency of S. aureus may be related to the environments analyzed; because the surfaces sampled are areas where emphasis is placed on the application of hygiene and disinfection protocols for ensure adequate decontamination