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

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

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

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

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

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

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

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

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

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

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.

Tipificación del cassette cromosómico estafilocócico de Staphylococcus aureus resistentes al meticilino en el estado de Aragua, Venezuela / Typification of the staphylococcal chromosome cassette of methicillin-resistant Staphylococcus aureus in the state of Aragua, Venezuela

RESUMEN Objetivos: Tipificar el casette SCCmec en cepas de Staphylococcus aureus resistentes a meticilino (SARM) en aislados clínicos de centros de salud del Estado Aragua-Venezuela y comparar la presencia de los genotipos SCCmec entre los centros de salud del estado y según el tipo de infección. Materiales y métodos: Durante enero y agosto de 2015 se estudiaron 81 cepas SARM de cuatro centros de salud del estado de Aragua en Venezuela. La resistencia al meticilino se midió con el método de Kirby-Bauer con discos de oxacilina (1 µgr) y cefoxitina (30 µgr). El gen mecA y el SCCmec se analizaron por la técnica de reacción en cadena de polimerasa múltiple. Resultados: 55 aislados (67,9%) amplificaron el gen mecA, y 24 cepas (43,6%) amplificaron el SCCmec. El SCCmec I fue el más frecuente, seguido de SCCmecIV y SCCmec III, representaron el 62,5%, 25% y 12,5%, respectivamente. El SCCmec I fue predominante en el centro de salud A (80%), mientras que el SCCmec IV se encontró en el centro de salud B (60%) y C (100%). En el centro de salud D, 50% resultó ser SCCmec I y 50% SCCmec IVd. Se encontró relación entre el SCCmec y el centro de salud con significancia estadística. En infecciones de piel y tejidos blandos y en las respiratorias predominó el SCCmec I con 63,2% y 50% respectivamente. Conclusiones: La frecuencia de SCCmec I y IV permitirá establecer nuevas medidas en el uso y control de la resistencia a los antibióticos.

ABSTRACT Objective: Typify the SCCmec cassette in methicillin-resistant strains of Staphylococcus aureus in clinical isolates from health centers in the State of Aragua-Venezuela and compare the presence of SCCmec genotypes among the state health centers and according to the type of infection. Materials and methods: 81 MRSA strains from four health centers of the Aragua-Venezuela State were studied. Methicillin resistance was performed with the Kirby-Bauer method with oxacillin (1 µg) and cefoxitin (30 µg) disks. The mecA gene and SCCmec were analyzed by the multiple PCR technique. Results: Only 55 isolates (67.9%) amplified the mecA gene, and 24 strains (43.6%) amplified SCCmec. SCCmec type I was the most frequency, followed by SCCmec IV and SCCmec III, representing 62.5%, 25% and 12.5%, respectively. SCCmec I was predominant in health center A (80%), while in B and C 60% and 100% respectively were SCCmec IV. At health center D, 50% turned out to be SCCmec I and 50% SCCmec IVd. A relationship was found between the SCCmec and the health center with statistical significance. SCCmec I predominated in skin and soft tissue and respiratory infections with 63.2% and 50%, respectively. There was no association between genotype and type of infection with a p value greater than 0.05. Conclusions: The prevalence of SCCmec I and IV will allow establishing new measures in the use of antibiotics and epidemiological control.

Tracking methicillin-resistant Staphylococcus aureus clones in a hospital in Southern Mexico / Seguimiento de clonas de Staphylococcus aureus resistentes a meticilina en un hospital en el sur de México

Abstract: Objective: To describe the clinical and molecular characteristics of methicillin-resistantStaphylococcus aureus(MRSA) strains that were collected in theHospital Regional de Alta Especialidad de Veracruz(HRV). Materials and methods: A total of 107 MRSA strains from individual patients were examined. The strains were collected between September 2009 and September 2010. The clinical and demographic characteristics of patients were analyzed; molecular typing by pulsed-field gel electrophoresis (PFGE), staphylococcal chromosomal cassette mec (SCCmec) typing and multilocus sequence typing were used to characterize the isolates. Results: Two PFGE patterns (NY/J and IB) were identified with 4 and 3 subtypes respectively. The isolates analyzed showed two SCCmec types (I and II) and two sequence types (ST): ST247 and ST5 related with the Iberian and New York/Japan clones respectively. Conclusion: This study establishes the presence of two very important clonal lineages of MRSA: New York/Japan and Iberian clone in the hospital environment.

Resumen: Objetivo: Describir las características clínicas y moleculares de cepas deStaphylococcus aureusresistentes a meticilina (SARM) que fueron recolectadas en el Hospital Regional de Alta Especialidad de Veracruz (HRV). Material y métodos: Un total de 107 cepas de SARM fueron analizadas en el presente estudio. Las cepas estudiadas fueron recolectadas de septiembre de 2009 a septiembre de 2010. Las características clínicas y demográficas de los pacientes fueron analizadas; la tipificación molecular de las cepas se hizo por electroforesis en campos pulsados, casete cromosomal estafilococócico (SCCmec, en inglés) y secuenciación de múltiples locus. Resultados: Dos patrones electroforéticos (NY/J y IB) fueron identificados con 4 y 3 subtipos respectivamente. Los aislamientos analizados mostraron dos tipos de SCCmec (I y II) y dos secuencias tipo (ST): ST247 y ST5 relacionados con las clonas Ibérica y Nueva York/Japón respectivamente. Conclusión: Este estudio estableció la presencia en el medio hospitalario de dos linajes clonales de SARM importantes: Nueva York/Japón e Ibérico.

Actividad antimicrobiana de Streptomyces sp. 6E3 aislado de concentrado de mineral* / Streptomyces sp. 6E3 antimicrobial activity isolated from mineral concentrate

RESUMEN El objetivo de este estudio fue determinar la actividad antimicrobiana de un cultivo de Streptomyces sp. 6E3 aislado de minerales frente a diferentes cepas patógenas, producir un extracto y estimar la concen tración mínima inhibitoria (CMI) de las fracciones contra Staphylococcus aureus resistente a meticilina (SARM). La cepa Streptomyces sp. 6E3 mostró actividad antimicrobiana principalmente contra Staphy lococcus aureus (S. aureus). Cinco de las seis fracciones presentaron actividad antimicrobiana y la más efectiva dio una CMI de 0,88 ug/mL frente a S. aureus ATCC 33862, 0,44 ug/mL frente a S. aureus ATCC 43300 y 1,76 ug/mL frente a S. aureus cepa SARM. Streptomyces sp. 6E3 tiene un potencial antimicrobiano frente a cepas de S. aureus resistentes a meticilina y no resistentes, siendo de interés la realización de más estudios sobre sus metabolitos activos.

ABSTRACT The objectives of this study were to determine the antimicrobial activity of a culture of Streptomyces sp. 6E3 isolated from minerals against different pathogenic strains, to produce an extract and to estimate the minimum inhibitory concentration (MIC) of the fractions against methicillin-resistant Staphylococ cus aureus (MRSA). Streptomyces sp. 6E3 showed antimicrobial activity primarily against Staphylococcus aureus (S. aureus). Five of the six fractions presented antimicrobial activity and the most effective gave a MIC of 0.88 ug / mL against S. aureus ATCC 33862, 0.44 ug / mL against S. aureus ATCC 43300 and 1.76 ug / mL vs. a S. aureus MRSA strain. Streptomyces sp. 6E3 has an antimicrobial potential against S. aureus strains resistant to methicillin and non-resistant, being of interest carrying out of more studies on its active metabolites.

Microbiologic characteristics and antibiotic resistance rates of diabetic foot infections / Perfil microbiológico e de resistência bacteriana no pé diabético infectado

ABSTRACT Purpose: the purpose of this research was to identify the sociodemographic and microbiological characteristics and antibiotic resistance rates of patients with diabetic foot infections, hospitalized in an emergency reference center. Methods: it was an observational and transversal study. The sociodemographic data were collected by direct interview with the patients. During the surgical procedures, specimens of tissue of the infected foot lesions were biopsied to be cultured, and for bacterial resistance analysis. Results: the sample consisted of 105 patients. The majority of patierns were men, over 50 years of age, married and with low educational level. There was bacterial growth in 95 of the 105 tissue cultures. In each positive culture only one germ was isolated. There was a high prevalence of germs of the Enterobacteriaceae family (51,5%). Gram-negative germs were isolated in 60% of cultures and the most individually isolated germs were the Gram-positive cocci, Staphylococcus aureus (20%) and Enterococcus faecalis (17,9%). Regarding antibiotic resistance rates, a high frequency of Staphylococcus aureus resistant to methicillin (63,0%) and to ciprofloxacin (55,5%) was found; additionally, 43,5% of the Gram-negative isolated germs were resistant to ciprofloxacin. Conclusions: the majority of patients were men, over 50 years of age, married and with low educational level. The most prevalent isolated germs from the infected foot lesions were Gram-negative bacteria, resistant to ciprofloxacin, and the individually most isolated germ was the methicillin resistant Staphylococcus aureus.

RESUMO Objetivo: identificar o perfil sociodemográfico, microbiológico e de resistência bacteriana em pacientes com pé diabético infectado. Métodos: tratou-se de estudo observacional, transversal que avaliou os perfis sóciodemográfico e microbiológico de pacientes portadores de pé diabético infectado internados em Pronto Socorro de referência. Os dados sociodemográficos foram coletados por meio de entrevista. Foram colhidos, durante os procedimentos cirúrgicos, fragmentos de tecidos das lesões podais infectadas para realização de cultura/antibiograma. Resultados: a amostra foi composta por 105 pacientes. O perfil sociodemográfico mais prevalente foi o de pacientes do sexo masculino, acima dos 50 anos, casados e com baixa escolaridade. Das 105 amostras de fragmentos de tecidos colhidos para realização de cultura e antibiograma, 95 foram positivas, com crescimento de um único germe em cada um dos exames. Houve predomínio de germes da família Enterobacteriaceae (51,5%). Germes Gram-negativos foram isolados em 60,0% das culturas e os espécimes mais isolados individualmente foram os cocos Gram-positivos, Staphylococcus aureus (20,0%) e Enterococcus faecalis (17,9%). Considerando-se os perfis de resistência bacteriana, verificou-se alta taxa de Staphylococcus aureus resistente à meticilina (63,0%) e à ciprofloxacino (55,5%); verificou-se, também, que 43,5% dos germes Gram-negativos eram resistentes à ciprofloxacino. Conclusões: o perfil sociodemográfico majoritário, foi o de homens, com mais de 50 anos e com baixa escolaridade. Concluímos que os germes mais prevalentes nas lesões podais dos pacientes diabéticos foram os Gram-negativos, resistentes ao ciprofloxacino e que o germe mais isolado individualmente foi o Staphylococcus aureus resistente à meticilina.

Resistencia inducible a clindamicina en Staphylococcus aureus resistentes a meticilina aislados de pacientes pediátricos en Paraguay / Inducible resistance to clindamycin in methicillin-resistant Staphylococcus aureus isolated from Paraguayan children

Resumen Introducción: El método de difusión de doble disco se presenta como una alternativa diagnóstica que permite identificar aislados de Staphylococcus aureus susceptibles a clindamicina, ante el aumento de resistencia a meticilina, reduciendo así la posibilidad de fallo en el tratamiento. Objetivo: Determinar la frecuencia de resistencia a clindamicina inducida por eritromicina en S. aureus resistentes a meticilina (SARM) aislados de niños paraguayos. Materiales y Métodos: Estudio observacional, descriptivo, de corte transversal. Se colectaron 145 aislados S. aureus que causaron infecciones de piel y tejidos blandos y osteo-articulares en pacientes pediátricos del Hospital Central del Instituto de Previsión Social en el período de diciembre-2012 a noviembre-2013. La resistencia a clindamicina se determinó por métodos automatizados y de difusión de doble disco. Se realizó reacción de polimerasa en cadena para genes ermA, ermB, ermC y msrA de aislados representativos. Resultados: La resistencia global a meticilina y clindamicina fue de 67 y 13%, respectivamente (11% atribuible al mecanismo de resistencia a clindamicina inducible). Los genes ermC y msrA fueron detectados individualmente en 25 y 17% de los aislados, respectivamente, mientras que un aislado presentó ambos genes en simultáneo. Discusión: La frecuencia de mecanismo de resistencia inducible a clindamicina señala la importancia de los métodos de difusión de doble disco en la práctica microbiológica, así como se encuentran en los límites de puntos de cortes considerados como aceptables para el uso de este antimicrobiano para infecciones cutáneas y osteo-articulares causadas por SARM.

Background: The double disc diffusion method is an alternative diagnostic that allows the identification of Staphylococcus aureus isolates apparently susceptible to clindamycin but that may develop resistance due to an induction phenomena, mainly asociated to the increase in resistance to methicillin, thus increasing the possibility of failure in the treatment. Aim: To determine the frequency of induced clindamycin resistance in methicillin-resistant S. aureus (MRSA) isolated from Paraguayan children. Materials and Methods: In this cross sectional study, we collected 145 S. aureus isolates that caused skin and soft tissue and osteoarticular infections in pediatric patients of the Central Hospital I.P.S. in the period from December-2012 to November-2013. Resistance to clindamycin was determined by automated methods and double disc diffusion. PCR was performed for ermA, ermB, ermC and msrA genes from representative isolates. Results: The global resistance to methicillin and clindamycin was 67 and 13%, respectively (11% attributable to the inducible mechanism). The ermC and msrA genes were detected individually in 25 and 17% of the isolates respectively while an isolate presented both genes simultaneously. Discussion: The frequency of inducible resistance to clindamycin indicates the importance of double disc diffusion methods in microbiological practice, as well as being within the cut off points considered acceptable for the use of this antibiotic for skin infections. and osteoarticular caused by MRSA.

Detection of potentially pathogenic bacteria on cell phones of hospital and university-based populations in Curitiba, southern Brazil. A cross-sectional study

ABSTRACT BACKGROUND: Cell phones have become indispensable for professional activities, including healthcare. Thus, they are possible sources of bacterial contamination. There is a scarcity of data in the literature regarding identification of risk factors for contamination of cell phones with pathogenic bacteria. OBJECTIVE: To compare the prevalence rates of Staphylococcus aureus (S. aureus), methicillin-resistant S. aureus (MRSA) and/or Enterobacteriaceae on cell phones belonging to hospital healthcare staff and university students in Curitiba, Paraná, Brazil, and to identify variables associated with such contamination. DESIGN AND SETTING: Cross-sectional study conducted in a public university's referral hospital and lecture buildings in 2017. METHODS: We sampled the surface of cell phones using the dipslide method, with Baird-Parker agar and Escherichia coli-coliform chromogenic (ECC) agar. We assessed the population's sociodemographic, behavioral and hygiene characteristics through interviews. Possible presence of S. aureus colonies was confirmed using agglutination tests, with evaluation of methicillin sensitivity. Colonies in ECC medium were counted. Stepwise logistic regression (forward P < 0.15) was performed to identify characteristics associated with bacterial contamination. RESULTS: The prevalence rates of S. aureus, MRSA and Enterobacteriaceae were, respectively, 32%, 4% and 3%. No difference was found between the hospital and university-based populations (P > 0.05). The only variable associated with bacterial contamination was the use of cloth/velvet/leather phone cases (odds ratio: 2.92; 95% confidence interval: 1.08-7.91). CONCLUSIONS: Potentially pathogenic bacteria were prevalent on the cell phones of this hospital and university population. Use of phone cases made of cloth-like material should be discouraged, especially in hospital settings.

Piomiositis en niños: experiencia en un hospital pediátrico de referencia en Argentina / Pediatric pyomyositis: experience in a Pediatric Reference Center in Argentina

Resumen Introducción: La piomiositis es la infección del músculo esquelético, entidad poco frecuente en pediatría. Objetivo: Describir las características de 21 niños con piomiositis. Métodos: Estudio prospectivo-analítico de niños ingresados con diagnóstico de piomiositis entre mayo de 2016 y abril de 2017 en el Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina. Resultados: Tasa de hospitalización de 21,5/10.000 admisiones (IC 95% 4,65- 71,43). La mediana de edad fue de 5,4 años (rango 1,25-11,6). El 90,4% presentaba algún factor predisponente. La localización más frecuente fue en miembros inferiores. La proteína C reactiva (PCR) estuvo elevada en todos los pacientes, con una media de 124 mg/L (DS 96), siendo significativamente más elevada en los pacientes que tuvieron hemocultivos positivos 206 (DS 101) vs 98 (DS 81), (p = 0,02). Se obtuvo rescate microbiológico en 17 pacientes (80,9%): Staphylococcus aureus resistente a meticilina (SARM) (n: 15) y Streptococcus pyogenes (n: 2). Se presentó con bacteriemia 23,8% de los pacientes. El 81% requirió drenaje quirúrgico. Conclusión: Staphylococcus aureus RM adquirido en la comunidad (SARMAC) es el patógeno predominante. En la selección del tratamiento empírico adecuado debería tenerse en cuenta: el patrón de resistencia local y el valor de PCR.

Background: Pyomyositis is the infection of skeletal muscle, a rare pathology in children. Aim To describe the characteristics of pyomyositis in pediatric patients. Methods: Prospective analytical study of hospitalized children diagnosed with pyomyositis from May 2016 to April 2017 at the Ricardo Gutiérrez Children's Hospital, Buenos Aires, Argentina. Results: Twenty-one patients with pyomyositis were identified. Annual rate: 21.5/10,000 admissions (95% CI 4.65-71.43). The median age was 5.4 years (range 1.25-11.6). The lower limbs were the most affected site. C-reactive protein (CRP) was elevated in all patients, with a mean of 124 mg/L (SD 96), being significantly higher in patients with bacteremia: 206 (DS 101) vs 98 (DS 81), p = 0.02. Bacterial cultures were positive in 17/21 (80.9%): 15 methicillin-resistant Staphylococcus aureus (MRSA), and 2 Streptococcus pyogenes. Blood cultures were positive in 5 (23.8%). Conclusion: MRSA-community acquired is the predominant pathogen in our setting. In the selection of the appropriate empirical treatment, the local resistance pattern and the CRP value should be taken into account.

Caracterización de los pacientes con bacteriemia por Staphylococcus aureus resistente a la meticilina en un hospital militar de alta complejidad / Characterization of patients with bacteremia by methicillin-resistant Staphylococcus aureus in a high-complexity military hospital

Resumen Introducción. En las Fuerzas Militares de Colombia, cerca de 500.000 de sus miembros asisten a consulta en los establecimientos sanitarios militares. En esta población, Staphylococcus aureus resistente a la meticilina (SAMR) se ha convertido en un agente patógeno de gran incidencia. Objetivo. Caracterizar los pacientes con diagnóstico de bacteriemia por SAMR en el Hospital Militar Central entre el 2012 y el 2015. Materiales y métodos. Se llevó a cabo un estudio observacional descriptivo de revisión retrospectiva de historias clínicas de pacientes mayores de 18 años, hospitalizados y con hemocultivos positivos para S. aureus resistente a la meticilina. Para la identificación de los pacientes se empleó el sistema Whonet, version 5.6. Resultados. De los 177 cultivos positivos para S. aureus, el 24,8 % (n=44) correspondió a SAMR, con mayor prevalencia en pacientes militares activos(n=20m 45,4 %). Se observó una frecuencia similar para la bacteriemia por SAMR adquirida en la comunidad y la adquirida en el hospital, siendo más frecuente (n=37, 84 %) el fenotipo de la comunidad en ambos grupos. El principal foco infeccioso fueron los tejidos blandos, seguidos por el tejido pulmonar. Se presentaron mayores tasas de complicaciones (61%, n=13) en la bacteriemia adquirida en el hospital; 34,9 % (n=15),de los pacientes tuvieron una estancia hospitalaria prolongada atribuible a las complicaciones desencadenadas por la bacteriemia. Conclusiones. La población más afectada por SAMR fueron los pacientes militares activos (n=20, 45,4 %), con una frecuencia similar de la bacteriemia adquirida en la comunidad (n=18, 43,2 %) y la adquirida en el hospital (n=25, 56,8 %), y el principal foco infeccioso fueron los tejidos blandos. Dados estos resultados, es necesario adelantar estudios para establecer la prevalencia de infecciones por SAMR en la piel.

Abstract Introduction: In Colombia, there are about 500,000 members in the national armed forces who consult military health institutions. In this population, methicillin-resistant Staphylococcus aureus (MRSA) has become a high-incidence pathogen. Objective: The aim of this study was to characterize patients with MRSA bacteremia in the Hospital Militar Central between 2012 and 2015. Materials and methods: This was an observational descriptive study with a retrospective review of clinical histories of hospitalized patients older than 18 years of age with positive blood cultures for methicillin-resistant S. aureus. The identification of the patients was made using the Whonet system, version 5.6. Results: From cultures positive for S. aureus, 24.8% were methicillin-resistant strains, with a higher prevalence in active military personnel. A similar frequency was observed for community-acquired MRSA bacteremias and those acquired at the hospital, with the community phenotype being the most frequent in both groups. The main infectious focus related to the development of bacteremia was soft tissue, followed by pulmonary tissue. There were higher complication rates in nosocomial bacteremias; 34.9% of the patients had prolonged stays attributable to complications triggered by the bacteremia. Conclusions: Active military personnel was the most affected population by MRSA, with a similar frequency in community-acquired and nosocomial bacteremias. The main infectious focus was soft tissue. Taking into account these data, studies that establish the prevalence of skin infections by MRSA should be carried out.

Detection of some virulence factors genes in Staphylococcus aureus isolated from different clinical cases

Staphylococcus aureus is one of the most important pathogenic type to humans, and the most common species responsible for a wide range of diseases such as furuncles, various abscesses, wounds abscesses resulting from surgical operations, dermatitis, soft tissue inflammation, arthritis, bones inflammation, bronchial pneumonia, inflammation of internal parts of the heart and injuries caused by toxins such as toxic shock syndorome and staphylococcus aureus syndrome and food poisoning. The current study aimed by finding the genes responsible for the virulence factors in S. aureus isolates by using the Single and Multiplex PCR mechanism (technology). A total of 60 specimens (urine, burn swabs, wound swaabs) from different clinical cases were collected from patients (in different age groups) who admitted to several health centers in Al-Diwaniyah Teaching Hospital, Iraq, during a period extending from October 2016 to January 2017. Some virulence factors were investigated for 30 isolate only of MRSA using Single and Multiplex PCR for detection virulence factor genes which both coa gene encoding production of coagulase, clfA gene encoding for clumpting factor, spa gene encoding for protein A, fnbA gene encoding for fibronectin binding proteins, luks gene encoding prouction of Panton Valentine Leukocidin (PVL). Results 30 (100%) were possess coa, clfA, spa and fnbA genes, 13 (43.3%) were possess luks gene

Molecular characteristics of methicillin-resistant Staphylococcus aureus isolates from hospital and community environments in northeastern Brazil

ABSTRACT This study characterized 30 MRSA isolates from intensive care unit (ICU) environment and equipment surfaces and healthy children. The SCCmec types I, IVa and V were detected in HA-MRSA isolates while CA-MRSA showed the SCCmec type IVa and V. Most isolates were classified as agr group II. All isolates presented the sei gene, and only HA-MRSA were positive for etb e tst genes. Three genotypes were related to Pediatric (ST5/SCCmecIV) and Berlin (ST45/SCCmecIV) clones. The present study showed molecular similarity between CA- and HA-MRSA isolates in hospital and community settings in a Brazilian region.

Daptomycin and vancomycin non-susceptible methicillin-resistant Staphylococcus aureus clonal lineages from bloodstream infection in a Brazilian teaching hospital

ABSTRACT Introduction: This study aimed to characterize Staphylococcus aureus isolates from bloodstream infections in patients attending a teaching hospital, between 2011 and 2015. Methods: The minimum inhibitory concentration for daptomycin, linezolid, oxacillin, teicoplanin, vancomycin, and trimethoprim/sulfamethoxazole was accessed by broth microdilution. SCCmec type and clonal profile were determined by molecular tests. Vancomycin heteroresistance was evaluated using screening tests and by population analysis profile/area under the curve. Results: Among 200 S. aureus isolates, 55 (27.5%) were MRSA, carrying SCCmec II (45.5%) or IV (54.5%). The most frequent MRSA lineages were USA100 (ST5-II) (45.5%) and USA800 (ST5-IV) (30.9%). Six isolates were confirmed as vancomycin heteroresistant, showing area under the curve ratio 1.1, 1.2 or 1.3 (four USA100, one USA800 and one USA1100 isolates). Conclusions: Daptomycin and vancomycin non-susceptible MRSA clonal lineages were found in bloodstream infections over five years, highlighting the importance of continuous surveillance of multiresistant bacteria in hospitals.

Staphylococcus aureus in tonsils of patients with recurrent tonsillitis: prevalence, susceptibility profile, and genotypic characterization

ABSTRACT Introduction: Bacterial tonsillitis is an upper respiratory tract infection that occurs primarily in children and adolescents. Staphylococcus aureus is one of the most frequent pathogens in the etiology of tonsillitis and its relevance is due to its antimicrobial resistance and persistence in the internal tissues of the tonsils. Tonsillectomy is indicated in cases of recurrent tonsillitis after several failures of antibiotic therapy. Material and methods: In this study we evaluated 123 surgically removed tonsils from patients who had history of recurrent tonsillitis. The tonsils were submitted to microbiological analysis for detection of S. aureus. The isolates were identified by PCR for femA gene. Antimicrobial susceptibility of the isolates was determined by disk diffusion tests. All isolates were submitted to PCR to detect mecA and Panton-Valentine leucocidin (PVL) genes. The genetic similarity among all isolates was determined by pulsed field gel electrophoresis. Results: Sixty-one S. aureus isolates were obtained from 50 patients (40.7%) with mean age of 11.7 years. The isolates showed high level resistance to penicillin (83.6%), 9.8% had inducible MLSb phenotype, and 18.0% were considered multidrug resistant (MDR). mecA gene was detected in two isolates and the gene coding for PVL was identified in one isolate. The genetic similarity analysis showed high diversity among the isolates. More than one genetically different isolate was identified from the same patient, and identical isolates were obtained from different patients. Conclusions: MDR isolates colonizing tonsils even without infection, demonstrate persistence of the bacterium and possibility of antimicrobial resistance dissemination and recurrence of infection. A specific clone in patients colonized by S. aureus was not demonstrated.

Molecular analysis, biofilm formation, and susceptibility of methicillin-resistant staphylococcus aureus strains causing community- and health care-associated infections in central venous catheters

Abstract INTRODUCTION: The behavior of methicillin-resistant Staphylococcus aureus (MRSA) isolated from central venous catheter-related infection was evaluated to determine its biofilm potential, antimicrobial resistance, and adhesion genes. METHODS: A total of 1,156 central venous catheters (CVC) were evaluated to screen for pathogens. Antimicrobial sensitivity, biofilm formation potential, and molecular analysis of MRSA were examined following standard guidelines. RESULTS: Of the 1,156 samples, 882 (76%) were colonized by bacteria or candida. Among the infected patients, 69% were male and 36% were female with median age of 32 years. Staphylococcus aureus infected 39% (344/882) of CVCs in patients. Of the 59% (208/344) of patients with MRSA, 57% had community acquired MRSA and 43% had hospital acquired MRSA. Linezolid and vancomycin killed 100% of MRSA; resistance levels to fusidic acid, doxycycline, clindamycin, azithromycin, amikacin, trimethoprim-sulfamethoxazole, gentamycin, tobramycin, and ofloxacin were 21%, 42%, 66%, 68%, 72%, 85%, 95%, 97%, and 98% respectively. Strong biofilm was produced by 23% of samples, moderate by 27%, and weak by 50% of MRSA. The presence of adhesion genes, sdrC and sdrD (90%), eno (87%), fnbA (80%), clfA and sdrE (67%), fnbB, sdrD (61%), and cna (51%), in most MRSA samples suggested that the adhesion genes are associated with biofilm synthesis. CONCLUSIONS: The superbug MRSA is a major cause of CVC-related infection. Antibiotic resistance to major classes of antibiotics and biofilm formation potential enhanced superbug MRSA virulence, leading to complicated infection. MRSA causes infection in hospitals, communities, and livestock.

Is community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) an emerging pathogen among children in Brazil?

ABSTRACT Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is spreading worldwide, but little is known about the epidemiology of this pathogen in Brazil. Objective: To evaluate clinical and microbiological features of children with S. aureus infections admitted to a university hospital. Methods: This was a cross-sectional study evaluating the potential risk factors for CA-MRSA, and a retrospective cohort evaluating in-hospital clinical outcomes. To include patients with both community and hospital-associated infections, we screened the results of the microbiological laboratory tests from January 1, 2012, to December 31, 2016. According to the phenotype, we classified the isolates in Methicillin-Susceptible S. aureus (MSSA), Hospital-Associated Methicillin-Resistant S. aureus (HA-MRSA), and CA-MRSA. Clinical data were collected from the patients' medical records. Results: We identified 279 cases of S. aureus infections (MSSA = 163, CA-MRSA = 69, HA-MRSA = 41). Overall, the incidence density of CA-MRSA and MSSA infections increased while the HA-MRSA incidence density decreased over the study period. CA-MRSA infected patients were more likely to present with skin and soft tissue infections (OR: 2.83, 95%CI: 1.54-5.33, p < 0.001) and osteomyelitis (OR: 4.76; 95%CI: 1.16-22.71, p = 0.014) when compared to MSSA and HA-MRSA infections. Unadjusted case fatality rates were similar between MSSA-infected patients (3.14%, 5/159) and CA-MRSA infected patients (3.80%, 3/79, p = 0.792), while HA-MRSA infected patients were more likely to die in the hospital (12.20%, 5/41, p = 0.013). Conclusions: CA-MRSA is an emergent pediatric pathogen in Brazil. Our results highlight the relevance of choosing an appropriate initial antimicrobial drug for treating children with severe S. aureus infections.

Tipos de spa no reportados en nuestro país en Staphylococcus aureus de pacientes adultos de un hospital escuela, Santa Fe, Argentina / Non reported spa types in our country in Staphylococcus aureus from adult patients of a school hospital, Santa Fe- Argentina

Staphylococcus aureus es un patógeno responsable de diversos cuadros clínicos. Los marcadores moleculares son útiles para el estudio de la epidemiología microbiana. Se estudiaron 22 aislamientos de S. aureus resistentes a meticilina (SARM) y 23 sensibles a meticilina (SASM) mediante mecA, cassette SCCmec, leucocidina de Panton Valentine (LPV) y polimorfismo spa; se analizaron datos de los pacientes. SASM predominó en muestras distintas de piel y partes blandas de internados, mientras SARM en partes blandas. Predominó el SCCmec tipo IV seguido del I. Se encontró baja presencia de LPV. En SARM hubo 11 tipos de spa diferentes, t019 fue el más frecuente y en pacientes ambulatorios. En SASM se hallaron 17 tipos con prevalencia del t189. El spa t002 estuvo presente en SASM y SARM. Se hallaron 11 tipos de spa no reportados en nuestro país.

Staphylococcus aureus is a pathogen associated a different kind of infection. Molecular markers are useful tools to study microbial epidemiology. Twenty two methicillin-resistant S. aureus (MRSA) and 23 methicillin-susceptible S. aureus (MSSA) were studied by mecA gene, SCCmec cassette, Panton Valentine leucocidin (PVL) and spa polymorphism. The clinical data patients were analyzed. MSSA was prevalent in samples different from skin and soft tissue (SST) and in hospitalized patients, whereas MRSA in SST. SCCmec type IV was predominant, followed spa; by type I. Low presence of PVL was found. In MRSA 11 different types of spa were detected, SCCmec; t019 was the most frequent and associated with outpatient, 17 types were found in MSSA and Panton Valentine t189 was prevalent. spa t002 was present in MSSA and MRSA. We found 11 types of spa not leucocidin reported in our country.

High frequency of methicillin-susceptible and methicillin-resistant Staphylococcus aureus in children under 1 year old with skin and soft tissue infections / Alta frequência de S. aureus (MSSA-MRSA) em crianças com menos de um ano deidade com infecções de pele e do tecido mole

Abstract Objective: Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. Method: A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with methicillin-resistant S. aureus and a representative sample of patients infected with methicillin-susceptible S. aureus were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. Results: A total of 182 patients, 65 with methicillin-susceptible S. aureus infections and 117 with methicillin-resistant S. aureus infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with methicillin-resistant S. aureus infections (p ≤ 0.05). Sixteen clonal complexes were identified and methicillin-susceptible S. aureus strains were more diverse. The most common cassette was staphylococcal cassette chromosomemec IVc (70.8%), which was linked to Panton-Valentine leukocidin (pvl). Conclusions: In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level.

Resumo Objetivo: O Staphylococcus aureus é responsável por um grande número de infecções na população pediátrica; contudo, as informações sobre o comportamento dessas infecções nessa população são limitadas. O objetivo do estudo foi descrever as características clínicas, epidemiológicas e moleculares de infecções causadas por Staphylococcus aureus suscetíveis e resistentes à meticilina (MSSA-MSRA) em uma população pediátrica. Método: Um estudo transversal descritivo foi realizado em pacientes entre 0 e 14 anos de idade de três instituições de alta complexidade (2008-2010). Todos os pacientes infectados com S. aureus resistentes à meticilina e uma amostra representativa de pacientes infectados com S. aureus suscetíveis à meticilina foram incluídos. As informações clínicas e epidemiológicas foram obtidas de prontuários médicos, e a caracterização molecular incluiu tipagem spa, Eletroforese em Gel de Campo Pulsado (PFGE) e Tipagem de sequências multilocus (MLST). Além disso, o Cassete Cromossômico Estafilocócico mec (SCCmec) e genes de fatores de virulência foram detectados. Resultados: 182 pacientes, 65 com infecções por S. aureus suscetíveis à meticilina e 117 com infecções por S. aureus resistentes à meticilina, foram incluídos no estudo; 41,4% dos pacientes com menos de um ano de idade. As infecções mais frequentes foram da pele e dos tecidos moles. Os históricos como internações em centros de atendimento e o uso prévio de antibióticos foram mais comuns em pacientes com infecções por S. aureus resistentes à meticilina (p ≤ 0,05). Dezesseis complexos clonais foram identificados, e as cepas de S. aureus suscetíveis à meticilina foram mais diversificadas. O cassete mais comum foi o Cassete Cromossômico Estafilocócicomec IVc (70,8%), relacionado à leucocidina de panton-valentine (pvl). Conclusões: Em comparação a outros locais, observamos uma prevalência de infecções em crianças com menos de um ano de idade na cidade; o que enfatiza a importância de conhecer a epidemiologia em nível local.