RESUMO
BACKGROUND: The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown. OBJECTIVES: In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH). The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated. METHODS: The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE) assays. Minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces. FINDINGS: ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5) and a thermometer (n = 1) used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR). Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of vancomycin induced biofilm formation by an ORSH strain on polystyrene. MAIN CONCLUSIONS: Sphygmomanometers and thermometers are fomites for the transmission of ORSH. A sub-lethal dose of vancomycin may favor biofilm formation by ORSH on fomites and catheter surfaces.
Assuntos
Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Fômites/microbiologia , Esfigmomanômetros/microbiologia , Staphylococcus haemolyticus/fisiologia , Termômetros/microbiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Humanos , Testes de Sensibilidade Microbiana , Oxacilina/farmacologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/transmissão , Staphylococcus haemolyticus/efeitos dos fármacos , Staphylococcus haemolyticus/isolamento & purificação , Vancomicina/farmacologiaRESUMO
Oxacillin-resistant Staphylococcus haemolyticus (ORSH) was found as the most prevalent (77.5%) species of coagulase-negative staphylococci associated with bacteremia in neonates making use of intravenous catheters in an intensive care unit of a Brazilian teaching hospital. Thirty-one blood isolates were confirmed as S. haemolyticus by sequencing of the 16S and clustered in 6 pulsed-field gel electrophoresis types (with 58% of the strains belonging to 2 predominant types B and D). S. haemolyticus was mostly oxacillin-resistant (90.3%) displaying multiresistance profiles (70.4%). However, the mecA gene was undetected in 22.6% strains. ORSH exhibited slime production on Congo-Red agar (67.7%), adherence to polystyrene (96.7%), and glass (87%) surfaces. Interestingly, ica-operon was detected in 58% strains, mostly belonging to the B, D, and F genotypes, which is a significantly higher percentage when compared to other studies conducted at different parts of the globe. Data indicated that ica operon and biofilm-forming ORSH are endemic in Brazilian nosocomial environment.
Assuntos
Bacteriemia/epidemiologia , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana Múltipla , Infecções Estafilocócicas/epidemiologia , Staphylococcus haemolyticus/isolamento & purificação , Bacteriemia/microbiologia , Aderência Bacteriana , Brasil/epidemiologia , Análise por Conglomerados , Infecção Hospitalar/microbiologia , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Genótipo , Hospitais de Ensino , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Dados de Sequência Molecular , Polissacarídeos Bacterianos/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Infecções Estafilocócicas/microbiologia , Staphylococcus haemolyticus/classificação , Staphylococcus haemolyticus/genética , Staphylococcus haemolyticus/fisiologiaRESUMO
BACKGROUND The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown. OBJECTIVES In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH). The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated. METHODS The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE) assays. Minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces. FINDINGS ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5) and a thermometer (n = 1) used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR). Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of vancomycin induced biofilm formation by an ORSH strain on polystyrene. MAIN CONCLUSIONS Sphygmomanometers and thermometers are fomites for the transmission of ORSH. A sub-lethal dose of vancomycin may favor biofilm formation by ORSH on fomites and catheter surfaces.
Assuntos
Humanos , Oxacilina/farmacologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/transmissão , Termômetros/microbiologia , Vancomicina/farmacologia , Infecção Hospitalar/microbiologia , Biofilmes/crescimento & desenvolvimento , Esfigmomanômetros/microbiologia , Staphylococcus haemolyticus/isolamento & purificação , Staphylococcus haemolyticus/efeitos dos fármacos , Staphylococcus haemolyticus/fisiologia , Antibacterianos/farmacologia , Resistência a Medicamentos , Testes de Sensibilidade Microbiana , Infecção Hospitalar/transmissão , Eletroforese em Gel de Campo Pulsado , EletroforeseRESUMO
Nas últimas décadas, os Staphylococcus coagulase-negativo, têm sido considerados como patógenos verdadeiros, sendo um dos principais grupos bacterianos responsáveis pelas infecções relacionadas a assistência a saúde (IRAS). O presente estudo teve como objetivo geral: avaliação da relação entre a resistência a oxacilina e a produção de biofilme de amostras Staphylococcus coagulase-negativo de origem comunitária e hospitalar. Neste sentido, foram desenvolvidos os seguintes objetivos específico: identificar ao nível de espécie os Staphylococcus coagulase-negativo; analisar por técnica fenotípica (Ágar vermelho do Congo) a produção de slime; avaliar quantitativamente, a produção de biofilme; correlacionar a produção de polissacarídeos extracelulares (slime) com a produção de biofilme; avaliar a relação da resistência a oxacilina como indicador da presença do gene mecA; avaliar a relação entre a concentração inibitória mínima e a concentração bactericida mínima para oxacilina; pesquisar a presença dos genes mecA, icaAD e atlE, pela técnica de PCR. Foi estudado um total de 150 amostras, sendo 50 isoladas de fômites, 50 isoladas de sangue e 50 isoladas de comunidade. Independente da origem, foram identificadas 14 espécies de Staphylococcus coagulase-negativo, sendo mais frequentes S. epidermidis 42,6%, S. haemolyticus 13,3% e S. cohnii cohnii 10,7%. A análise geral da expressão fenotípica de slime mostrou que 64% das amostras avaliadas eram produtoras de slime. Das 150 amostras testadas neste estudo, 95,3% foram produtoras de biofilme. Ao considerarmos a análise da quantificação do biofilme em relação às origens das amostras estudadas não encontramos diferenças significativas e a maioria das amostras foi considerada moderadamente produtora de biofilme. O gene mecA foi detectado em 6 amostras comunitárias, 34 amostras de fômites e 34 amostras de sangue. Não houve diferença significativa entre as amostras de fômites e sangue...
In recent decades, coagulase-negative Stapphylococci have been considered as true pathogen, one of the major bacterial groups responsible for hospital infection. The present study aimed to: assess the relationship between oxacillin resistance and biofilm production samples coagulase-negative Stapphylococci of community and hospital. In this sense, we have developed the following specific objectives: to identify to species level coagulase-negative Staphylococci; analyze by phenotypic test (Congo red Agar) slime production, evaluate quantitatively the biofilm production; correlate the production of extracellular polysaccharides (slime) with biofilm production; evaluate the relationship of resistance to oxacillin as an indicator of the presence of the mecA gene; evaluate the relationship between minimal inhibitory concentration and minimum bactericidal concentration for oxacillin; investigate the presence of the mecA gene, atlE and icaAD, by PCR. We studied a total of 150 samples, 50 were isolated from fomites, 50 from community and 50 isolated from blood. Regardless of origin, 14 species of coagulase-negative Stapphylococci were identified , being more frequent 42.6% S.epidermidis, 13.3% S. haemolyticus and 10.7% S. cohnii cohnii. A general analysis of the phenotypic expression of slime showed that 64% of the samples were slime producers...
Assuntos
Humanos , Adolescente , Biofilmes/crescimento & desenvolvimento , Coagulase/sangue , Oxacilina/farmacologia , Resistência Microbiana a Medicamentos , Staphylococcus/patogenicidade , Fômites/microbiologia , Polissacarídeos/provisão & distribuição , Sangue/microbiologiaRESUMO
Os computadores hospitalares são fômites novos e desconhecidos e sua introdução nos quartos dos pacientes já é uma realidade em alguns hospitais modernos. Cinqüenta amostras de teclados de computadores desktop hospitalares foram examinadas no período de agosto a outubro de 2005. Microrganismos mesófilos aeróbios foram detectados em 82 por cento (41/50) dos teclados examinados; fungos em 84 por cento (42/50); enterococos em 24 por cento (12/50) e estafilococos em 28 por cento (14/50) dos teclados. O nível de contaminação nos teclados foi compatível com o encontrado em diversas superfícies. Porém, Staphylococcus sp. coagulase-positivos (8 por cento) e Enterococcus sp. (25 por cento), com perfis de resistência monitorados pelos sistemas internacionais de vigilância, foram encontrados, caracterizando-os como fontes potenciais na disseminação de patógenos hospitalares. O uso de uma cobertura protetora, a desinfecção periódica e uma política de uso que dificulte a disseminação de patógenos são recomendados.