RESUMEN
In this study, we report the characterization of a strain of Enterococcus faecium vanA, which grows only in the presence of vancomycin (VDEfm-UEL). The bacterium was isolated from the feces of a female patient who had undergone surgical treatment of Reinke’s edema and was receiving intravenous vancomycin therapy for infection with methicillin/oxacillin-resistant Staphylococcus aureus, a postoperative complication. Antimicrobial dependence was further confirmed by the vancomycin E-test. VDEfm-UEL was also shown to be resistant to ampicillin, ciprofloxacin, chloramphenicol, erythromycin, levofloxacin, penicillin, rifampicin, and teicoplanin. The putative virulence genes efaA, gelE and esp were detected by PCR. The ddl gene from VDEfm-UEL was cloned and sequenced. Vancomycin dependence seems to be associated with the insertion of a nucleotide in that sequence, which results in a frame-shift mutation, introducing a premature stop codon. This is the first report of vancomycin-dependent E. faecium isolation in a university hospital in Brazil.
Asunto(s)
Anciano , Femenino , Humanos , Antibacterianos/farmacología , Enterococcus faecium/efectos de los fármacos , Resistencia a la Vancomicina/genética , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Enterococcus faecium/genética , Enterococcus faecium/aislamiento & purificación , Heces/microbiología , Mutación del Sistema de Lectura/genética , Hospitales Universitarios , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Reacción en Cadena de la PolimerasaRESUMEN
Escherichia coli strains isolated from 100 urine samples taken from patients with urinary tract infections (UTI) and from 20 normal fecal (NF) samples were examined for serum resistance, mannose-resistant hemagglutination of human erythrocytes (MRHA) and for production of aerobactin, hemolysis and colicin. Among the UTI E. coli strains, 79% produced aerobactin, 69% showed serum resistance, 44% produced MRHA, 32% were beta-hemolytic and 22% were colicinogenic. A greater proportion of UTI E. coli strains produced aerobactin, colicin V, beta-hemolysis and MRHA when compared to NF strains. Production of MR hemagglutins was significant correlated with that of aerobactin and hemolysin. These results suggest that the presence of aerobactin may be a significant etiological factor in UTI, and that the production of MR adhesins and of hemolysin also might contribute to the virulence of these strains