Distribution of Enterococci in Hong Kong

Objectives: To study the distribution of hospital isolates of enterococci from urines, bile, blood and body fluids and to evaluate different methods for the identification of enterococci.Methods: Enterococci isolated from urine, bile, blood and body fluids collected during 1997 and 1998 were identified by polymerase chain reaction (PCR), API 20 Strep and conventional biochemical tests.Results: A total of 498 non-duplicate enterococci were studied: 398 and 43 isolates from urine and bile, respectively, 49 from blood, two from cerebrospinal fluid and six from body fluids. Both API 20 Strep and PCR gave the same identification results for 240 Enterococcus faecalis isolates, 45 E. faecium isolates and one isolate each of E. gallinarum and E. Casseliflavus. These isolates were re-defined by conventional biochemical tests. PCR could correctly identify 303 (98%) isolates while API 20 Strep could only correctly identify 287 (93%) isolates (99% of E. faecalis and 57–87% of the other Enterococcus sp.). Thus, PCR was used in the identification of the remaining isolates and the identity of isolates other than E. faecalis was subsequently confirmed by biochemical tests.Conclusions: The majority of enterococci isolated wasE. faecalis (81%) while only 15% were E. faecium and 4% the other enterococcal species. PCR could correctly identify E. faecalis while the identity of other enterococcal species had to be confirmed by biochemical tests.