Anomalies in species identification of enterococci from veterinary sources using a commercial biochemical identification system.
OBJECTIVE
A commercial biochemical panel ID kit was used to identify presumptive enterococci isolates of veterinary or agricultural origin obtained during different steps of culture.


RESULTS
Fifty isolates identified as enterococci using a genus PCR assay were tested for genus and species identification using the BBL Crystal Identification Gram-Positive ID kit (Becton Dickinson, Sparks, MD, USA). Following sub-culture of the isolates three times, 59% agreement with the original panel ID was obtained. After four and six sub-cultures, percentage agreement increased to 61 and 64%, respectively. Nineteen of the 50 cultures were identified as both Enterococcus faecalis and E. faecium.


CONCLUSIONS
As a result of the variability between speciation of isolates following re-culture, additional methods for speciation are warranted.


CONCLUSIONS
This study suggests that the identification of the genus and species of non-human enterococcal isolates can vary greatly during successive passages when using this kit.
Hudson
C R
CR
Antimicrobial Resistance Research Unit, USDA-ARS, Russell Research Center, Athens, GA 30605, USA. chudson@saa.usda.gov
Fedorka-Cray
P J
PJ
Jackson-Hall
M C
MC
Hiott
L M
LM
D000818:Animals; D015373:Bacterial Typing Techniques / Q000379:methods*; D002417:Cattle; D002645:Chickens / Q000382:microbiology; D016983:Enterococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D013293:Enterococcus faecalis / Q000235:genetics / Q000302:isolation & purification; D016984:Enterococcus faecium / Q000235:genetics / Q000302:isolation & purification; D005516:Food Microbiology; D005638:Fruit / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D034421:Sus scrofa / Q000382:microbiology; D014675:Vegetables / Q000382:microbiology