RESUMEN
INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) can be difficult to detect at the clinical practice. METHODS: We analyzed 140 MRSA isolates from inpatients to correlate the antimicrobial susceptibility with the SCCmec types. RESULTS: Type III (n = 63) isolates were more resistant to ciprofloxacin, clindamycin, cloramphenicol, erythromycin, gentamicin, and rifampin than type IV (n = 65) ones (p < 0.05). Moreover, type IV isolates were susceptible to tetracycline (100%) and trimethoprim/sulfamethoxazole (98%), while type III isolates presented resistance to them. CONCLUSIONS: In regions where these SCCmec types are prevalent, the detection of specific resistant phenotypes could help to predict them, mainly when there are no technical conditions to SCCmec typing.
Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Staphylococcus aureus Resistente a Meticilina/genética , Tetraciclina/farmacología , Combinación Trimetoprim y Sulfametoxazol/farmacología , Cromosomas Bacterianos/genética , ADN Bacteriano/genética , Genotipo , Humanos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana/métodos , FenotipoRESUMEN
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infections have changed since certain non-multiresistant MRSA lineages have emerged in hospitals. In this study, 99 MRSA isolates, 77 from a public and 22 from a private hospital, were characterized. METHODS: Isolates were tested for antimicrobial susceptibility, whereas staphylococcal chromosomal cassette mec (SCCmec) typing and Panton-Valentine leukocidin genes were assessed by polymerase chain reaction. Pulsed-field gel electrophoresis and multilocus sequence typing analyses were carried out to determine the MRSA lineages. RESULTS: High rates of resistance were found to erythromycin (96%), ciprofloxacin (93%), and clindamycin (90%). The SCCmec types found were as follows: type II (14.2%), III (62.6%), and IV (23.2%). Approximately 85% of type III isolates was related to the Brazilian epidemic clone in both hospitals. For type IV isolates, 94.4% were related to both USA400/ sequence type (ST) 1 and USA800/ST5 lineages in the public hospital, whereas the USA400/ST1, USA800/ST5, USA1100/ST30, and EMRSA (Epidemic MRSA)-15/ST22 lineages were detected in the private hospital. Among the SCCmec II isolates, approximately 85% were related to the USA100/ST5 lineage. Three MRSA isolates were positive to Panton-Valentine leukocidin genes. CONCLUSION: The study showed that there was an emergence of USA400/ST1, USA800/ST5 SCCmec IV, and USA100/ST5 SCCmec II MRSA lineages in both hospitals. There was a dissemination of them in the public hospital and a polyclonal presence of the MRSA isolates in the private hospital. The spread of these lineages can be facilitated by the characteristics of the health institution.
Asunto(s)
Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Tipificación Molecular , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Antibacterianos/farmacología , Toxinas Bacterianas/genética , Brasil/epidemiología , ADN Bacteriano/genética , Exotoxinas/genética , Variación Genética , Genotipo , Hospitales , Humanos , Leucocidinas/genética , Staphylococcus aureus Resistente a Meticilina/genética , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Reacción en Cadena de la Polimerasa , Factores de Virulencia/genéticaRESUMEN
INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) can be difficult to detect at the clinical practice. METHODS: We analyzed 140 MRSA isolates from inpatients to correlate the antimicrobial susceptibility with the SCCmec types. RESULTS: Type III (n = 63) isolates were more resistant to ciprofloxacin, clindamycin, cloramphenicol, erythromycin, gentamicin, and rifampin than type IV (n = 65) ones (p < 0.05). Moreover, type IV isolates were susceptible to tetracycline (100%) and trimethoprim/sulfamethoxazole (98%), while type III isolates presented resistance to them. CONCLUSIONS: In regions where these SCCmec types are prevalent, the detection of specific resistant phenotypes could help to predict them, mainly when there are no technical conditions to SCCmec typing.