Identification of corynebacteria isolated from body fluids and evaluation of their antibiotic susceptibilities

ABSTRACT Ph. D. Thesis IDENTIFICATION OF CORYNEBACTERIA ISOLATED FROM BODY FLUIDS AND EVALUATION OF THEIR ANTIBIOTIC SUSCEPTIBILITIES Fahriye EKŞİ, M.D. Gaziantep University Graduate School of Health Sciences Department of Microbiology Supervisor: Iclal BALCI, M. D., Professor January 2003 The aim of this study was to identify Corynebacteria other than C. diphtheriae and to perform their antibiotic susceptibilities which isolated from routine cultures of body fluids arrived from various clinics to the laboratory of the Microbiology and Clinical Microbiology Department at the Medical Faculty Hospital of the Gaziantep University. From February 2000 through June 2001, 254 ( 2.8 %) coryneform bacteria were grown on 9079 clinical specimens of which 202 (79.5 %) were from urine, 21(8.2 %) from blood cultures, 20 (7.9 %) from tracheal aspirates, 7 (2.8 %) from semen or urethral discharges and 4 (1.6 %) from cerebrospinal fluids. Strains were classified to species with both classical methods and the API Coryne system 2.0 (Bio Merieux, France) and some additional biochemical tests were also performed. Of the clinical specimens, 56 (22.0 %) C. amycolatum, 46 (18.1 %) C. minutissimum, 46 (18.1 %) C. striatum, 26 (10.2 %) C.jeikeium, 19 (7.4 %) C. group G, 9 (3.5 %) C. afermentans/coyleae, 8 (3.1 %) C. glucuronolyticum-seminale, 7 (2.8 %) C. urealyticum, 4 (1.5 %) Brevibacterium spp., 3 (1.1 %) C. argentoratense, 3 (1.1 %) C. propinquum, 3 (1.1%) C. accolens, 2 (0.8 %) Cellulomonas spp./Microbacterium viiispp., 2 (0.8 %) Arîrobacter spp., 1 (0.3 %) C. group Fl, 1 (0.3 %) C. auris/ Turicella otitidis, 1 (0.3 %) C. macginleyi isolates were identified. Seventeen strains could not be differentiated. Corynebacterium amycolatum (25.7 %), C. minutissimum (21.8 %) and C. striatum (11.9 %) were mostly obtained from urine, C. jeikeium (52.3 %) mostly from blood and C. striatum (95 %) mostly from tracheal aspirates. Antibiotic susceptibilities of the identified strains were done with ATB STAPH 5 (susceptibility test for staphylococci) kit of the API System (Bio Merieux, France). For susceptibility tests, antibiotics such as penicillin, oxacillin, cephalothin, ampicillin-sulbactam, gentamicin, netilmicin, erythromycin, clindamycin, pefloxacin, ciprofloxacin, tetracycline, co-trimoxazol, nitrofurantoin, rifampicin, vancomycin, teikoplanin were used. Strains of C. jeikeium, C. urealyticum, C. amycolatum and C. striatum were found to have multiple resistance against used antibiotics, but all isolates were susceptible to vancomycin and teicoplanin. Although coryneform bacteria are members of the human body flora, they tend to cause serious opportunistic infections. Therefore these organisms should be classified to species regarding the host factors when they are isolated and their antibiotic susceptibility tests should be performed properly. Key words: Coryneform bacteria, identification, antibiotic susceptibility, Corynebacterium spp. IX