Phenotypes and genotypes of vancomycin-resistant enterococci isolated during long-term follow-up in a patient with recurrent bacteremia and colonization
Yeh, K.-M.; Lu, J.-J.; Siu, L.-K.; Peng, M.-Y.; Chang, F.-Y.
Journal of Microbiology Immunology and Infection 35(4): 243-248
2002
ISSN/ISBN: 1684-1182 PMID: 12542250 Document Number: 546790
Twenty-seven isolates of vancomycin-resistant enterococci were obtained at monthly intervals from a bed-ridden man with hypoxic encephalopathy. During the 28-month period of the patient's hospitalization, 3 episodes of bacteremia and one episode of catheter-related infection caused by vancomycin-resistant enterococci occurred. Rectal swabs showed colonization of vancomycin-resistant enterococci for more than 2 years. Three months after termination of antimicrobial therapy, the rectal colonization for vancomycin-resistant enterococci was eradicated. Four species (Enterococcus faecium, Enterococcus gallinarum, Enterococcus faecalis, and Enterococcus casseliflavus) were identified among the 27 vancomycin-resistant enterococcus isolates. Three non-clonal related patterns were found among 17 strains of E. faecium by pulsed-field gel electrophoresis. All of the 3 E. faecalis isolates were of the VanB phenotype, but of the vanA genotype. Linezolid had the most potent in vitro activity against these vancomycin-resistant enterococcus isolates, with minimum inhibitory concentrations >2 microg/mL. Eighty-five percent of these vancomycin-resistant enterococcus isolates were susceptible to tetracycline and 66% were susceptible to quinupristin-dalfopristin. Although a high genetic correlation of E. faecium was identified in the patient with prolonged hospitalization, the isolation of 3 genetically unrelated colonized isolates suggested a lack of correlation between infection and colonization. Precautions against resistant organisms, adapted antibiotic policies, and elimination of patient carriage are useful for controlling the spread of vancomycin-resistant enterococci.