Bacteriologic profile, antibiotics resistance pattern, and outcomes of patients admitted to Lancet General Hospital from June 2022 to June 2023: A retrospective cohort study

Background Prior studies indicated increased antimicrobial resistance in Ethiopia, with related health, economic, and environmental costs. Knowing an institutions and population microbiologic profile allows for proper antibi-otic treatment, which substantially impact patients' outcomes such as healthcare related costs, morbidity, and mortality. The current study assessed the bacteriologic profile, resistance pattern, and treatment outcome in Lancet General Hospital. Method A retrospective cohort study on the bacteriologic profile, antibiotics resistance pattern, and outcome of patients was done on 128 eligible patients who were admitted to Lancet General Hospital from June 2022 to June 2023. Data from all hospitalized patients with culture-confirmed infection were analyzed. SPSS version 26.0 was used to analyze the data. Association between independent and dependent variables was analyzed using binary logistic regression model. Results Gram-negative bacteria were recovered in 77% of the cases. Extended-spectrum beta-lactamase producing Enterobacteriaceae was found in 37.5% (54) isolates and carbapenem resistant bacteria were identified in 27.8% of patients. In-hospital mortality from multidrug resistant bacterial infection was 14.8%. Age ≥ 65 years, presence of septic shock, and presence of carbapenem-resistant bacteria were independently associated with in-creased in-hospital mortality. Conclusion High number of resistant microorganisms was isolated, and increased mortality was documented from infections caused by carbapenem-resistant bacteria. Multi-center studies should be done to determine the extent of resistant organisms in health facilities throughout the country. epidemiology, and the findings should be factored into clinical decision making and program design for disease prevention, screening, and treatment. It also calls for further prospective research to learn more about the conditions in the context of additional relevant personal and clinical characteristics

Análisis crítico de un antimicrobiano sub-óptimo, de frecuente sobre-utilización e inadecuada dosificación: vancomicina / Critical review of a suboptimal antibiotic, frequently overused and inappropriately dosed: vancomycin

Resumen Introducción: Vancomicina, terapia estándar para enterococos y estafilococos resistentes a β-lactámicos tradicionales (Staphylococcus aureus [SARM] y Staphylococcus coagulasa negativa), tiene extenso uso empírico en infecciones nosocomiales. Farmacológicamente débil, de estrecho margen terapéutico y farmacocinética poco predecible, es un fármaco sub-estándar según criterios contemporáneos. Tiene excesivo uso, por sobrediagnóstico de infecciones bacterianas y, en infecciones genuinas, por sobre-estimación etiológica de patógenos β-lactámico-resistentes. Últimamente han surgido nuevas amenazas a su efectividad: peores desenlaces en infecciones por SARM con CIM en rango alto de sensibilidad y resistencia de enterococos. Hay frecuente administración inadecuada en: dosis e intervalos, ausencia de dosis de carga inicial, falta de monitoreo con concentraciones plasmáticas, inadecuada dosificación en presencia de insuficiencia renal o diálisis e, importantemente, mantención de uso en ausencia de clara documentación de su necesidad. Nuevos fármacos anti-estafilocócicos no han permitido un reemplazo generalizado de vancomicina por lo que ésta mantiene un importante rol en la medicina contemporánea. Conclusiones: Una comprensión de las fortalezas y debilidades del fármaco, así como de la cambiante epidemiología y propiedades microbiológicas de los patógenos relevantes, al igual que un uso prudente y selectivo, permitirán optimizar su uso y mantener su rol terapéutico en la medicina actual y futura.

Background: Vancomycin, standard parenteral therapy for Gram positive cocci resistant to traditional beta-lactam antibiotics (Staphylococcus aureus and coagulase negative staphylococci [CNS]) and Enterococcus spp, frequent agents of nosocomial infections, is extensively used empirically in that setting. However, its pharmacological weakness, narrow therapeutic margin and poorly predictable pharmacokinetics, make it a suboptimal drug according to contemporary criteria. Vancomycin is over utilized due to both, overestimation of bacterial infections and, in genuine cases, overestimation of the etiological role of these resistant cocci, either nosocomially or community acquired. New threats narrow further its therapeutic role: poorer outcomes in infections with higher vancomycin MIC and resistance by enterococci. It is frequently given at inappropriate dosage and intervals, failing to: give loading dose when recommended, measure blood levels, adjust dosing to changing renal function and continued use when not necessary. Newer anti staphylococcal drugs haven't replaced completely the role of vancomycin, which maintains its usefulness in contemporary medicine. Conclusion: Understanding the strengths and weaknesses of vancomycin, current epidemiology and microbiology of infections for which it may be indicated, as well as the proper administration and monitoring, together with a prudent and selective indication will allow to preserve its present and future utility in the changing medical scenario.

The study of reduced susceptibility of methicillin resistant Staphylococcus aureus to various antibiotics with special reference to glycopeptides in a tertiary care hospital in central India

Background: Staphylococcus aureus has emerged over the past several decades as a leading cause of hospital-associated and community acquired infections. Methicillin resistant S. aureus (MRSA), which are often resistant to several classes of antibiotics, is the most common cause of nosocomial infections and pose a great threat to the world. Vancomycin is regarded as the first-line drug for treatment of MRSA but resistance to this drug is being reported now a day.Methods: It was carried out for a period between January 2014 to June 2017 in the microbiology diagnostic laboratory. MRSA detection was performed by cefoxitin disk diffusion method. Screening for the vancomycin intermediate and the vancomycin resistant S. aureus (VISA and VRSA respectively) was carried out by using vancomycin screen. MIC (minimum inhibitory concentration) of vancomycin was tested by agar dilution method and E strip on all MRSA isolates.Results: A total of 287 S. aureus clinical isolates were included in the study. All MRSA were inoculated on vancomycin screen agar. Visible growth was present in 8 isolates. Five (3.73%) MRSA isolates with MIC of 4 were termed VISA (vancomycin intermediate S. aureus) by agar dilution method. Six isolates had the MIC of 4 and were termed as VISA.Conclusions: As disc diffusion method is not recommended by CLSI for S. aureus, vancomycin screen agar and MIC determination by either of the methods viz. agar dilution or E test can be used.

Methicillin-resistant Staphylococcus aureus pneumonia in diabetics: a single-center, retrospective analysis / 中华医学杂志(英文版)

Background@#Methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is an important issue with significant morbidity and mortality in clinical practice, especially in diabetes mellitus (DM). Studies focusing on S. aureus pneumonia in DM is limited, we sought to make a relatively comprehensive exploration of clinical characteristics, antimicrobial resistance, and risk factors for mortality of S. aureus pneumonia in DM and non-diabetics mellitus (non-DM).@*Methods@#A retrospective study was conducted in Ruijin Hospital from 2014 to 2017. The characteristics of DM and non-DM patients were assessed, including demographics, comorbidities, using of invasive mechanical ventilation, Hemoglobin A1c (HbA1C), confusion, urea, respiratory rate, blood pressure, age ≥65 years (CURB-65) score, length of hospital stay, clinical outcomes, antimicrobial susceptibility. Independent risk factors for mortality were identified by univariate and multivariate logistic regression analysis.@*Results@#A total of 365 patients with S. aureus pneumonia were included in our study, including 144 with DM and 221 non-DM. DM patients were more susceptible to MRSA infection (65.3% vs. 56.1%, P > 0.05), suffered from much severer pneumonia with a higher CURB-65 score, invasive mechanical ventilation rate (46.5% vs. 28.1%, P < 0.01) and mortality rates (30.6% vs. 23.1%, P > 0.05); almost all DM patients had higher antimicrobial resistance than non-DM patients, the DM group had a higher coinfection rate (47.2% vs. 45.7%, P > 0.05), and Acinetobacter baumannii was the most common bacterium in DM, while Klebsiella pneumoniae ranked first in patients with non-DM. Independent risk factors for pneumonia-related mortality were MRSA and CURB-65. Higher HbA1c levels were linked to a higher MRSA infection and co-infection rate and more severe pneumonia, leading to an increase in mortality.@*Conclusions@#DM patients with poor glucose control are more susceptible to MRSA infection. They suffer from higher antimicrobial resistance, a higher co-infection rate, and much severer pneumonia than non-DM. MRSA itself is an independent risk factor for mortality in all patients.

Analysis of Resistance to Macrolide–Lincosamide–Streptogramin B Among mecA-Positive Staphylococcus Aureus Isolates

OBJECTIVES: Genetic determinants conferring resistance to macrolide, lincosamide, and streptogramin B (MLSB) via ribosomal modification such as, erm, msrA/B and ereA/B genes are distributed in bacteria. The main goals of this work were to evaluate the dissemination of MLSB resistance phenotypes and genotypes in methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from clinical samples. METHODS: A total of 106 MRSA isolates were studied. Isolates were recovered from 3 hospitals in Tehran between May 2016 to July 2017. The prevalence of MLSB-resistant strains were determined by D-test, and then M-PCR was performed to identify genes encoding resistance to macrolides, lincosamides, and streptogramins in the tested isolates. RESULTS: The frequency of constitutive resistance MLSB, inducible resistance MLSB and MSB resistance were 56.2%, 22.9%, and 16.6%, respectively. Of 11 isolates with the inducible resistance MLSB phenotype, ermC, ermB, ermA and ereA were positive in 81.8%, 63.6%, 54.5% and 18.2% of these isolates, respectively. In isolates with the constitutive resistance MLSB phenotype, the prevalence of ermA, ermB, ermC, msrA, msrB, ereA and ereB were 25.9%, 18.5%, 44.4%, 0.0%, 0.0%, 11.1% and 0.0%, respectively. CONCLUSION: Clindamycin is commonly administered in severe MRSA infections depending upon the antimicrobial susceptibility findings. This study showed that the D-test should be used as an obligatory method in routine disk diffusion assay to detect inducible clindamycin resistance in MRSA so that effective antibiotic treatment can be provided.

Utilidad de Trimetoprima-sulfametoxazol en épocas de S. aureus meticilino resistente de la comunidad / Usefulness of trimethoprim-sulfamethoxazole in times of community-acquired methicillin-resistant S. aureus.

Trimetoprima-sulfametoxazol (TMP-SMX) tiene actividad in vitro contra cepas de Staphylococcusaureus, en especial las cepas resistentes a la meticilina de la comunidad (SAMR-Co), Éste es considerado un antibiótico útil debido a su bajo costo, amplio espectro y posibilidad de administración por vía oral dada su adecuada biodisponibilidad y sabor agradable. Se realizó esta revisión narrativa de la literatura para evaluar el uso de TMP-SMX en comparación con otras opciones disponibles en el tratamiento de las infecciones por SAMR-Co en niños (AU)

Trimethoprim/sulfamethoxazole (TMP-SMX) has in vitro activity against Staphylococcus aureus, especially against community-acquired methicillin-resistant (CAMR) strains. It is considered to be a useful antibiotic because of its low cost, broad spectrum, and possibility of oral administration because of its adequate bioavailability and agreeable flavor. A review of the literature was performed to evaluate the use of TMP-SMX compared to available options for the treatment of CAMR infections in children (AU)

Leucocidina de Panton Valentine en cepas SAMR aisladas de pacientes del Hospital Universitario de Maracaibo / Panton Valentine leukocidin in MRSA strains isolated from patients at the University Hospital of Maracaibo

Staphylococcus aureus se presenta como un patógeno cada vez más importante, debido al arsenal de factores de virulencia que presenta, sumado a su elevada capacidad de generar resistencia a los antimicrobianos Los objetivos de esta investigación fueron: confirmar la resistencia a meticilina mediante la amplificación del gen mecA y detectar la presencia de los genes que codifican el factor de virulencia leucocidina de Panton Valentine (PVL). Se investigaron estos genes empleando la reacción en cadena de polimerasa (PCR). Todos los aislamientos presentaron el gen mecA, el 50% de estas cepas resultó portador del gen para PVL. El 54,17% de las muestras de pacientes pediátricos, dio positivo para esta leucocidina. El mayor porcentaje de aislamiento se encontró en muestras de piel y tejidos blandos (85,7%).

Staphylococcus aureus is an increasingly important pathogen, due to the arsenal of virulence factors which presents, in addition to its high capacity to generate antimicrobial resistance. The objectives of this research were: confirm methicillin resistance by amplification the mecA gene and the presence of genes that encode Panton Valentine leucocidin (PVL) virulence factor. These genes have been investigated using polymerase chain reaction (PCR). All isolates showed the mecA gene, 50% of these strains were carrying the gene for PVL. 54,17% of the samples from pediatric patients, yield positive for this leukocidin. The highest percentage of isolation was found in samples of skin and soft tissues (85.7%).

MÉTODOS DE TIPIFICACIÓN Y EPIDEMIOLOGÍA MOLECULAR DE Staphylococcus aureus CON RESISTENCIA A LA METICILINA / TIPIFICATION METHODS AND MOLECULAR EPIDEMIOLOGY OF Staphylocuccus aureus WITH METHICILLIN RESISTANCE

El interés actual del estudio de Staphylococcus aureus deriva de su elevada frecuencia de cepas resistentes a los antibióticos que causa frecuentes brotes de infección, especialmente, el S. aureus con resistencia a meticilina (SARM). El objetivo de esta revisión fue estudiar la estructura genética poblacional y el origen de los aislamientos de SARM. La tipificación del cassette cromosómico mec estafilocócico es el método más importante para identificar y definir la naturaleza clonal del S. aureus con resistencia a meticilina. Los estudios de epidemiología molecular evidencian un patrón de diseminación de unas pocas cepas que son las responsables del importante problema mundial. Existe el predominio de clones pandémicos de SARM asociado a infecciones hospitalarias (SARM-AH), que ha han sido reemplazados en la actualidad por clones de origen comunitario (SARM-AC). En Colombia, predomina el clon pediátrico y el chileno entre los aislamientos hospitalarios. Sin embargo, en la actualidad una variante del clon comunitario USA300 prevalece en las infecciones adquiridas en la comunidad y en el hospital, desplazando los clones hospitalarios como ocurre en el resto de mundo. El entendimiento de la epidemiología y clonalidad de las infecciones por S. aureus tiene importantes implicaciones en el control de la emergencia de cepas con multirresistencia y el esparcimiento de clones resistentes y sensibles a meticilina.

Recent interest in the study of Staphylococcus aureus derives from the high frequency of antibiotic-resistant strains that cause frequent outbreaks of infection, especially Methicillin-resistant S. aureus (MRSA). The objective of this review was to study the population genetic structure and the origin of MRSA isolation. Classification of staphylococcal cassette chromosome mec (SCCmec) is the most important method to identify and define the S. aureus methicillin-resistant clonal nature. Molecular epidemiologic studies have demonstrated dissemination patterns of few strains which are responsible for the important worldwide problem. There is a predominance of pandemic clones of MRSA associated to hospital-acquired infections (HA-MRSA) which has been replaced today by community-acquired strains (CA-MRSA). In Colombia, the pediatric clone and the Chilean clone predominate between hospital isolations. However, currently, there is a variant community clone USA300 prevailing in infections acquired in the community and in the hospital, displacing HA-MRSA as it happens in the rest of world. Understanding the epidemiology and clonality of S. aureus infections has important implications for future efforts to control of the emergence of multidrug-resistant strains and the spread of clones resistant and sensible to methicillin.

Factores relacionados con la colonización por Staphylococcus aureus / Factors related with colonization by Staphylococcus aureus / Fatores relacionados com a colonização por Staphylococcus aureus

Staphylococcus aureus tiene gran capacidad para colonizar la piel y las mucosas de los seres humanos y de diferentes animales. Varios estudios evidencian el papel de dicha colonización en la patogénesis y la epidemiología de las infecciones causadas por S. aureus. Se ha demostrado que los portadores nasales constituyen una fuente importante de propagación de la bacteria; una amplia proporción de las infecciones estafilocócicas invasivas asociadas al cuidado de la salud son de origen endógeno, y la colonización por cepas de S. aureus resistentes a meticilina (SARM), aún mal entendida, origina mayores complicaciones. La importancia de la colonización se ha definido con más profundidad en ambientes hospitalarios, pero recientemente se han hecho estudios en la comunidad con resultados contradictorios sobre la relación colonización-infección. En esta revisión se presentan algunas características relevantes del proceso de colonización por S. aureus, incluyendo las cepas de SARM, y se consideran los factores humanos y del microorganismo que influyen en él. Asimismo, se hace una revisión de los estudios colombianos al respecto.

Staphylococcus aureus has a particular ability to colonize the skin and mucosae of human beings and different animal species. Several studies have demonstrated the important role of such colonization in the pathogenesis and epidemiology of staphylococcal infections. Nasal carriers have been shown to be an important source for S. aureus spread. Most invasive nosocomial S. aureus infections have been confirmed to have endogenous origin, and colonization with methicillin-resistant (MRSA) strains may have adverse consequences. However, the dynamics of the MRSA carrier state remains poorly understood. Although the clinical significance of S. aureus colonization has been demonstrated mostly in hospitals, recent studies have also investigated it in community settings, with contradictory results concerning the colonization- infection relationship. This review focuses on relevant aspects of the dynamics of colonization by S. aureus. It describes human and microorganism factors involved in the colonization process including MRSA strains. Additionally, a summary is presented on Colombian studies on this subject matter.

Staphylococcus aureus tem grande capacidade para colonizar a pele e as mucosas dos seres humanos e de diferentes animais. Vários estudos evidenciam o papel de dita colonização na patogêneses e a epidemiologia das infecções causadas por S. aureus. Demonstrou- se que os portadores nasales constituem uma fonte importante de propagação da bactéria; uma ampla proporção das infecções estafilocócicas invasivas sócias ao cuidado da saúde são de origem endógena, e a colonização por cepas de S. aureus resistentes a meticilina (SARM), ainda mal entendida, origina maiores complicações. A importância da colonização se definiu com mais profundidade em ambientes hospitalares, mas recentemente se fizeram estudos na comunidade com resultados contraditórios sobre a relação colonização-infecção. Nesta revisão se apresentam algumas características relevantes do processo de colonização por S. aureus, incluindo as cepas de SARM, e se consideram os fatores humanos e do microrganismo que influem nele. Assim mesmo, faz-se uma revisão dos estudos colombianos ao respeito.

Producción de Enterotoxina y Biofilm en Aislamientos Clínicos de Staphylococcus aureus Resistente a Meticilina / Enterotoxin and Biofilm Production in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

S. aureus se ha convertido en un problema de salud pública, debido a la dificultad que representa el tratamiento de las infecciones causadas por SARM. El propósito de esta investigación fue determinar la producción de enterotoxinas A, B, C y D y la producción de biofilm en aislamientos de SARM. Se estudiaron 50 cepas aisladas de diferentes tipos de muestras clínicas. La detección de enterotoxinas se realizó por la técnica de aglutinación en fase reversa y la producción de biofilm mediante: agar rojo congo y el método en microplacas de cultivos celulares. La producción de enterotoxina se observó en 9 cepas (18%), siendo la enterotoxina D (64%) la más prevalente, seguida de la B (27%) y la A (9%). Se demostró una asociación significativa entre la producción de enterotoxina y el tipo de muestra de la que provenía la cepa. La producción de biofilm se constató en 30% y 98% de las cepas por los métodos de agar rojo congo y microplacas de cultivos celulares, respectivamente; sólo en 15 cepas (30%) se observó correlación de ambos ensayos, se demostró que el método en microplacas de cultivo celular es más eficaz para detectar la producción de biofilm en S. aureus.

S. aureus has become a public health problem, due to the difficulty of treating infections caused by methicillin-resistant S. aureus (MRSA). The purpose of this research was to determine the production of enterotoxins A, B, C and D and the production of biofilm in clinical isolates of MRSA. Fifty MRSA strains isolated from different types of clinical samples were studied. Detection of enterotoxins was carried out using the technique of reversed phase agglutination, while biofilm production was studied through two tests: Congo red agar and the microplate cell culture method. Enterotoxin production was observed in 9 strains (18%); enterotoxin D (64%) was the most prevalent, followed by B (27%) and A (9%). A significant association was shown between enterotoxin production capacity and the type of sample that came from the strain. Biofilm production was found in 30% and 98% of the strains using the Congo red Agar and microplate cell culture methods, respectively. A correlation of both trials was observed in only 15 strains (30%). It was shown that the microplate cell culture method is more effective for detecting biofilm production in S. aureus strains.

Tipo de cassette cromosómico estafilocócico en cepas clínicas de Staphylococcus aureus resistentes a meticilina / Staphylococcal Chromosomal Cassette Type in Clinical Strains of Methicillin-Resistant Staphylococcus aureus

Staphylococcus aureus resistente a meticilina (SAMR) presenta una proteína de unión a la penicilina, la PBP2a codificada por el gen mecA, que se encuentra en un elemento genético móvil llamado cassette cromosómico estafilocócico (SCCmec). El presente estudio se realizó para examinar la susceptibilidad antimicrobiana, producción de leucocidina de Panton-Valentine (PVL) y tipo de SCCmec presente en cepas aisladas de 54 pacientes en un hospital durante un período de tres meses. Las pruebas de susceptibilidad antimicrobiana se realizaron mediante el método de difusión en agar y el mecA, PVL y los tipos de SCCmec se determinaron usando la reacción en cadena de polimerasa (PCR). Veintinueve (29) cepas correspondieron al SCCmec tipo IV (54%), 22 al SCCmec tipo I (40%), 2 al SCCmec tipo IA (4%) y 1 al SCCmec IIIB (2%). Diecinueve cepas (35%) resultaron positivas para PVL, todas SCCmec tipo IV. Cuarenta cepas (74%) expresaron multi-resistencia. Todos los aislamientos fueron sensibles a vancomicina, teicoplanina, linezolid, tigeciclina y moxifloxacina. No se encontró asociación estadísticamente significativa entre la presencia del gen PVL, la resistencia antimicrobiana y el tipo de SCCmec (p>0,05). Los SCCmec tipos IV y I son los más frecuentes en las cepas SAMR circulantes en la institución.

Methicillin-resistant Staphylococcus aureus (MRSA) presents a protein that binds to penicillin, the PBP2a, encoded by the gene mecA, located in a mobile genetic element called the staphylococcal chromosomal cassette (SCCmec). This study was conducted to examine the antimicrobial susceptibility, Panton-Valentine leukocydine (PVL) production and the staphylococcal chromosomal cassette mec (SCCmec) type for MRSA isolates from 54 patients in a hospital during a three-month period. Antimicrobial susceptibility testing was performed using an agar diffusion method; mecA, PVL and SCCmec types were determined using polymerase chain reaction (PCR). Twenty-nine strains (29) corresponded to type IV SCCmec (54%), 22 to type I SCCmec (40%), 2 to type IA SCCmec (4%) and 1 to SCCmec IIIB (2%). Nineteen strains (35%) were positive for PVL, all of type IV SCCmec. Forty strains (74%) expressed multiresistance. All MRSA isolates were susceptible to vancomycin, teicoplanin, linezolid, tygecicline and moxifloxacina. No statistically significant association was found between the presence of the PVL gene, antimicrobial resistance and the SCCmec type (p>0.05). SCCmec types IV and I are the most frequent in the MRSA strains circulating in the institution.

Nasal carriage of Methicillin‑resistant Staphylococcus aureus among healthy population of Kashmir, India.

Background: Nasal colonisation with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) is being increasingly reported, especially in places where people are in close contact and where hygiene is compromised. The aim of this study was to find out prevalence of methicillin resistant S.aureus (MRSA) colonising anterior nares of healthy subjects. Materials and Methods: Nasal swabs of healthy subjects were collected aseptically and cultured using standard microbiological protocols. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method according to CLSI guidelines. Methicillin resistance was detected by cefoxitin disc diffusion method and confirmed by minimum inhibitory concentration (MIC) and amplification of mecA gene by PCR. Strain typing of MRSA strains was done by PFGE. Results: Out of 820 samples, S.aureus was isolated from 229 (27.92%) subjects. Of the 229 isolates, 15 were methicillin resistant. All S. aureus isolates were susceptible to vancomycin. Nasal carriage of MRSA was found to be 1.83% among healthy population. The isolates were found to be polyclonal by PFGE analysis. Conclusion: High prevalence of MRSA is a cause of concern and strategies to interrupt transmission should be implemented.

Characterization of Community-Associated Methicillin-Resistant Staphylococcus aureus in Gwangju, Korea

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important nosocomial pathogens worldwide. This study was performed to investigate the characterization of MRSA isolated from healthy persons in Gwangju area. A total of 404 nasal swab samples was collected during October 2011 and May 2012 in Gwangu, Korea. A survey on MRSA was conducted with meat distributors (n=230), pre-school children (n=108), officers (n=66), respectively. To confirm the MRSA, polymerase chain reaction (PCR) for the S. aureus specific gene and mecA gene was performed. A total of 34 (8.4%) MRSA isolates was isolated from 404 nasal swab samples: 6.1% (14/230) from meat distributors, 16.7% (18/108) from pre-school children, and 3.0% (2/66) from officers samples, respectively. The most prevalent antimicrobial resistance observed in the MRSA isolates was to ampicillin 100% (34/34), followed by penicillin 97.1% (33/34), oxacillin 94.1% (32/34) and erythromycin 52.9% (18/34). All MRSA isolates were then characterized by panton-valentine leukocidin (pvl) gene detected by PCR, staphylococcal cassette chromosome mec (SCCmec) typing, and pulsed-field gel electrophoresis (PFGE) with Sma I digestion. 34 MRSA isolates from nasal carriage were pvl gene negative, SCCmec type IV; 73.5% (25/34), type II; 17.6% (6/34), type III; 2.9% (1/34), and untypable; 5.9% (2/34), respectively. 34 MRSA isolates showed 16 PFGE patterns. These results indicated that isolation rates of community-associated methicillin-resistant S. aureus (CA-MRSA) from healthy persons were low (8.4%), but continuous surveillance and monitoring should be performed to prevent the spread of MRSA in the community.

The non-association of Panton-Valentine leukocidin and mecA genes in the genome of Staphylococcus aureus from hospitals in South Western Nigeria.

Purpose: Virulence genes play important roles in pathogenesis of infections caused by S. aureus. The aim of this study was to determine the prevalence of PVL, eta and mecA genes in S. aureus isolated from patients in South-Western Nigeria. Materials and Methods: In this study, a total of 116 S. aureus isolates from the clinical specimens submitted to laboratories in tertiary hospitals in the South Western Nigeria were used. Antibiotic susceptibility test was carried out to determine the susceptibility pattern of the isolates using multiple antibiotics disc. Minimum inhibitory concentration (MIC) was also carried out to determine the degree of resistant of the isolates to methicillin. PCR was used to screen for the presence of PVL, eta, and mecAgenes. Results:mecA gene was detected in 48 (41.4%) of 116 strains of S. aureus. The MIC 50 and MIC 90 for mecA negative strains were 1 and 8 μg/ml, respectively while the MIC 50 and MIC 90 for mecA positive were >256 μg/ml. Twenty eight (24.1%) of 116 isolates were PVL gene positive with none of them mecA+. The prevalence of community acquired MRSA (CA-MRSA) was estimated to be 6.9% using molecular techniques. No localization of mecA gene and PVL gene on the genome of the entire S. aureus strains studied. Site of isolation of organism /specimen type was found to be associated with the prevalence of PVL+ and mecA+ S. aureus (P< 0.01). Conclusion: This study concludes that the PVL+ MRSA is rare and the prevalence of CA-MRSA is low in South-Western, Nigeria.

Staphylococcus aureus resistente a meticilina en trabajadores del centro integral de salud de la Universidad Católica Santo Toribio e d Mogrovejo- Chiclayo 2009 / Methicillin resistant Staphylococcus aureus in workers of integral health center of The Catholic University Santo Toribio e Mogrovejo- Chiclayo 2009

Objetivo: Determinar la frecuencia de S. aureus resistente a Meticilina (SARM) en trabajadores del Centro Integral de Salud de la Universidad Catolica Santo Toribio de Mogrovejo. El estudio: Se incluyo en el estudio al total de trabajadores del Centro (n=35). A cada uno se le realizo dos hisopados, uno en las fosas nasales y otro en la faringe. Las muestras se sembraron en placas con agar sangre y manitol salado. Se incubaron en atmosfera de CO2 a 37oC por 24 horas. Se realizo coloracion Gram, prueba de catalasa y coagulasa. Para el antibiograma, se utilizo el metodo de Kirby Bauer (CLSI). Los antibioticos evaluados fueron ciprofloxacina (5ug), clindamicina (2ug), eritromicina (15ug), levofloxacina (5ug), oxacilina (1ug) y vancomicina (30ug). Hallazgos: Se aislo 8 cepas de S. aureus sensibles a meticilina y 6 cepas de Streptococcus pyogenes -hemolitico. Conclusiones: No hubo prevalencia de S. aureus resistente a Meticilina en los trabajadores del Centro Integral de Salud de la Universidad Catolica Santo Toribio de Mogrovejo.(AU)

To determine the prevalence of methicillinresistant S. aureus in workers of Integral Health Center of the Catholic University Santo Toribio de Mogrovejo. The study: All employees of the Center were included (n = 35). Each worker underwent two swabs, one in the nose and another in the pharynx. Samples were inoculated in blood agar and manitol salt plates. The plates were incubated in a CO2 atmosphere at 37°C for 24 hours. Gram staining, catalase and coagulase test were performed. For antibiotic susceptibility testing, we used the method of Kirby Bauer (CLSI). The antibiotics evaluated were ciprofloxacin (5ìg), clindamycin (2ìg), erythromycin (15ìg), levofloxacin (5ìg), oxacilin (1ìg), vancomycin (30ìg). Findings: 8 strains of methicillinsensitive S. aureus and 6 strains of â-hemolytic Streptococcus pyogenes were isolated. Conclusions: There was no prevalence of methicillin-resistant S. aureus in workers Integral Health Center at the Catholic University Santo Toribio de Mogrovejo. Control of risk factors, biosecurity measures implemented and the participation of all workers in a Health Center, contribute to the monitoring of MRSA.(AU)

Comparative genomic analysis of ST239-spa t037 MRSA and ST239-spa t030 MRSA / 中华微生物学和免疫学杂志

Objective To identify critical genes in evolution of Staphylococcus aureus (S.aureus).Methods A total of 2457 genes from two whole genomes of S.aureus strains were amplified for fabricating whole genome microarray,which was employed for comparative genome hybridization (CGH) analysis of 23 strains of divergent MRSA clones,including ST239-spa t037 and ST239-spa t030.Representatives of differential genes were confirmed by PCR.Results Four gene clusters were identified to be associated with evolution of major epidemic MRSA clones.The four gene clusters were specific to ST239-spa t030,and belonged to three known genomic islands (vSa4,prophage ΦSa1 and ΦSa3).Eight genes were variable expressed in ST239-spa t030 MRSA from different coutries.Conclusion The acquisition of genomic islands vSa4,prophage ΦSa1 and ΦSa3 enhanced the virulence and resistance of ST239-spa t030 MRSA,and contributed to its rapid replacement of ST239-spa t037 MRSA in China.

Profile of Antimicrobial Resistance of Staphylococcus aureus and Molecular Epidemiologic Characterization of Methicillin-resistant Staphylococcus aureus (MRSA) Isolated from Hands of People Using Multitude Facilities

BACKGROUND: The purpose of this study was to investigate perception of hand hygiene and actual hand washing practices of people who used public facilities as well as the presence of indicator bacteria and food-borne pathogens on their hands. Data from this study will be used as a tool for public education and provide basic information on the potential risk for the spread of infectious disease by hands. MATERIALS AND METHODS: Sixty S. aureus and 15 methicillin-resistant S. aureus (MRSA) were recovered from 500 swab samples from hands of people in public places, including super markets and amusement facilities in Gwangju Metropolitan City during February to May 2011. Using conventional methods and the Vitek system, all of the isolates were confirmed as Staphylococcus auerus (S. aureus). Antimicrobial susceptibility was determined by performing disk diffusion testing according to the Clinical Laboratory Standard Institute guidelines. The minimum inhibition concentrations (MICs) of MRSA isolates were tested using E-test strips. To confirm the MRSA, polymerase chain reaction (PCR) for the S. aureus-specific gene and mecA gene was performed. Gene detection using PCR, SCCmec typing, Panton-Valentine Leukocidin (PVL), and Multilocus sequence typing (MLST) were performed on all isolates of MRSA. RESULTS: Of 60 S. aureus isolates, 48 (80%) harbored at least one type of enterotoxin gene: two, three, four, and five types of enterotoxin gene were found in 16 (26.7%), seven (11.7%), 10 (16.7%), and eight (13.3%) isolates, respectively. The most prevalent antimicrobial resistance observed in the S. aureus isolates was to penicillin (92%, 55/60), followed by erythromycin (35%, 21/60), oxacillin (32%, 19/60), and ampicillin (23%, 14/60). No resistance was observed against vancomycin, clindamycin, linazolid, rifampin, imipenem, trimethoprim/sulfamethoxazole, and telithromycin. In this study, based on molecular characterization of MRSA isolates, all MRSA, except for one isolate, belonged to ST72 and SCCmec type IV. Eleven of 15 (78.6%) MRSA were ST72:SCCmecIV:t324. CONCLUSIONS: In this study, we detected serious pathogens, including S. aureus and MRSA, from swab samples of peoples' hands. Most S. aureus isolates harbored the enterotoxin gene and the types of MRSA isolated in this study were community-associated MRSA, indicating the importance of washing hands for public health.

Current concepts in the management of bacterial skin infections in children.

Bacterial skin infections in children vary widely clinically, starting from mild superficial folliculitis to deep necrotizing fasciitis. The causative organisms are mostly Staphylococcus aureus and Streptococcus, with occasional involvement of Gram-negative organisms. Treatment of even the milder forms of bacterial skin infections is of importance because of the long-term morbidity associated with them. However, because of global emergence of resistant strains of bacteria, treatment of these conditions is becoming increasingly difficult. The current antibacterial resistance patterns in organisms causing skin and soft tissue infections and the problems encountered in their management in children have been discussed.

Tipificación molecular y fenotípica de Staphylococcus aureus resistentes a meticilina (SAMR) en un hospital universitario / Molecular and phenotypical typification of methicillin resistant Staphylococcus aureus (MRSA) strains in a university hospital

Objective: To typify by molecular and phenotypical methods, MRSA strains, isolated from patients and nurses to establish their possible clonal origin. Materials and Methods: 50 MRSA strains isolated in a teaching hospital in Maracaibo (Venezuela) were analyzed. The typification of MRSA strains was performed by means of pulsed-field gel electrophoresis (PFGE) and antibiotyping. Results: In patients, 12 clusters (I-XII) and 19 antibiotypes were found; whereas in the health-care personnel, 6 clusters (I-VI) and two antbiotypes were detected. There was no statistically significative association between antibiotypes and band patterns obtained by PFGE (p>0.05). Conclusions: By means of detection of resistance markers and PFGE, it is feasible to discrimínate the nature of the clinical strains of MRSA. The obtained results show the possible nosocomial transmission of MRSA strains and their clonal spread in hospital departments, particularly at the ICU.

Objetivo: Tipificar por métodos moleculares y fenotípicos, las cepas SAMR aisladas de pacientes y personal de enfermería para establecer su posible origen clonal. Materiales y Métodos: Se analizaron 50 cepas SAMR aisladas en un Hospital Universitario de Maracaibo (Venezuela). La tipificación se efectuó mediante electroforesis en gel de campo pulsado (EGCP) y antibiotipia. Resultados: Entre pacientes, se obtuvieron 19 antibiotipos y 12 grupos (I-XII); mientras que, en el personal de salud, por EGCP se detectaron seis grupos (I-VI) y dos antibiotipos. No se encontró asociación estadísticamente significativa entre los antibiotipos y patrones de bandas obtenidos por EGCP (p > 0,05). Conclusiones: Por medio de la detección de marcadores de resistencia y mediante la EGCP, es factible diferenciar la naturaleza de las cepas SAMR de origen clínico. Los resultados obtenidos demuestran la posible transmisión intrahospitalaria de cepas SAMR; así como, su diseminación clonal en los servicios del hospital, particularmente en la UCI, durante el período estudiado.

Nosocomial Infectious Bacterial Contamination onResidents' White Coats and Neckties / 대한임상미생물학회지

BACKGROUND: Doctors' white coats and neckties can become contaminated with potentially pathogenic bacteria and have a possibility of causing cross infections. Our objective was to determine the level of bacterial contamination and detect methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and Clostridium difficile present on the white coats and neckties of residents. METHODS: We sampled 28 long-sleeved white coats and 14 neckties worn by residents. The tested sites for white coats were the cuffs and lower front surfaces, and for neckties, the lower surfaces. Impressions of these sites were taken with the plates containing blood agar (BAP), mannitol salt agar supplemented with oxacillin (6microgram/mL), enterococcus screening agar supplemented with vancomycin (6microgram/mL) and phenyl ethanol agar. The colonies grown on each plate were Gram stained and identified by standard microbiological methods. RESULTS: Of the 28 white coats, 7 (25.0%) carried MRSA, and of the 14 neckties, 1 (7.1%) carried MRSA. The majority of white coats (96.4%) and all neckties (100.0%) carried methicillin-resistant coagulase negative staphylococci (MRCNS). None of the white coats and neckties carried VRE or C. difficile. CONCLUSION: Our results showed that white coats and neckties worn by residents were contaminated with MRSA and MRCNS. The preventive measures for clothing-borne cross contamination should be considered, especially when performing invasive procedures or having close contact with patients.