Detection of the mecA and femA genes, molecular markers of methicillin resistance, in Staphylococcus spp. isolated from patients admitted to a neonatal intensive care unit.

• Autor(a) principal: Moussallem, Bruno Campolino
• Data de Publicação: 2007
• Outros Autores: Kury, Charbell Miguel Haddad, Medina-Acosta, Enrique
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Revista Científica da Faculdade de Medicina de Campos
• Texto Completo: https://www.fmc.br/ojs/index.php/RCFMC/article/view/151
• topic: Diagnóstico; Reação em Cadeia da Polimerase; Resistência a meticilina; Staphylococcus coagulase negativo; Diagnosis; Polymerase chain reaction; methicillin resistance; coagulase negative Staphylococcus

The mechanism of resistance to beta-lactamic antibiotics in Staphylococcus spp. is, in part, associated to the expression of the penicillin- binding protein PBP2a, which main characteristic is the altered low-affinity for penicillins. The beta-lactamics bind to PBPs, membrane integral transpeptidases that participate in the initial phase of cell wall synthesis, changing their conformation and inducing a process, not clear yet, that leads to death of the bacteria. PBP2a substitutes PBPs that exhibit normal penicillin-binding activities, conferring an efficient defense against these drugs. PBP2a is the product of the mecA gene that is absent in methicillin susceptible strains. The level of methicillin resistance is influenced by a cytoplasmic protein, the product of the femA (fem, Factor Essential for methicillin resistance) gene, that is also involved in the biosynthesis of cell wall. The objective of the present study was the detection of the mecA and femA genes by the polymerase chain reaction, PCR, in Staphylococcus spp. strains obtained form newborns admitted to Neonatal Intensive Care Unit of the Hospital dos Plantadores de Cana in the of city Campos dos Goytacazes, Rio de Janeiro, Brazil. The frequency of infections with coagulase negative Staphylococcus was 88.6%. The frequency of oxacillin resistance was 79.5%. The frequency of the mecA+ genotype was 56.8% (62.8% of the resistant strains were mecA+ and 40% were mecA+/femA+). These data demonstrate a high prevalence of infections with methicillin resistant coagulase negative Staphylococcus in the patients admitted to the Neonatal Intensive Care Unit.