Expansion of Identification Panel of Enterococci by Conventional Methods

Abstract Background Enterococcus species (spp) represent part of the normal flora of the human gastrointestinal tract. However, recently they have gained greater interest due to their ability to emerge as one of the most important nosocomial pathogens worldwide. The conventional method for Enterococcal identification can be made reliable via involvement of multiple biochemical reactions to reach definitive diagnosis in case of resource constraint labs where automated methods may not be affordable. This study aimed to expand the conventional biochemical panel involved in identification of Enterococcus spp which made it on equal footing with the automated identification. Methods This study included 308 samples sent for routine culture and sensitivity at microbiology lab. Samples were collected from different departments at Ain Shams University Hospitals. 50 isolates were selected randomly to perform automated identification through Vitek 2 Compact system as well as perform further conventional biochemical testing as PYR test and Modified salt broth test. Results Our study showed frequency of isolation of E.faecalis, E.faecium and E.gallinarum are 70%, 26% and 4% respectively among the studied isolates. Pyrrolidonyl arylamidase (PYR) test was rapid and easy for interpretation. Modified salt broth together with PYR showed high accuracy. As regard antimicrobial susceptibility test, Penicillin showed the highest resistance among enterococcal species. Conclusion the conventional biochemical panel: PYR and modified salt broth involved in identification of Enterococcus spp can be on equal footing with the automated identification.