title: Current status of antibiograms of Listeria ivanovii and Enterobacter cloacae isolated from ready-to-eat foods in Alice, South Africa.
abstract: This study assessed the antimicrobial susceptibility of 51 Listeria ivanovii and 33 Enterobacter cloacae strains isolated from various ready-to-eat foods sold in Alice, South Africa. Isolates were identified using standard microbiological tests and further confirmed using API 20E and API Listeria kits. The disc diffusion technique was used to screen for antimicrobial susceptibility against 15 antimicrobials; minimum inhibitory concentration of five antibiotics was determined by the broth dilution method. All the strains of E. cloacae (100%) and 96% of L. ivanovii isolates were resistant to at least four or more of the antibiotics; nineteen antibiotypes were obtained based on the antibiotics used in the study. Antibiotype A5: AR PGR VAR ER APR was predominant in both L. ivanovii (23.5%) and E. cloacae (57.5%) isolates. Marked susceptibility of Listeria ivanovii was observed against chloramphenicol, ciprofloxacin, streptomycin and trimethoprim/sulfamethoxazole (100%) each while E. cloacae registered 100% susceptibility to ciprofloxacin only. Various percentages of susceptibility was reported to chloramphenicol and gentamicin (91%) each, nalidixic acid (97%) and streptomycin (94%). The MIC(90 )ranged from 0.004-7.5 µg/mL( )with E. cloacae being the most susceptible organism. The study demonstrated the presence of multi-resistant strains of bacteria in ready-to-eat-foods and speculates that these foods could serve as important vehicles transmitting multi-resistant bacteria to humans.
authors.affiliation: Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, PMB X1314, Alice 5700, South Africa. nyenjem@yahoo.com
authors.forename: Mirriam E
authors.initials: ME
authors.lastname: Nyenje
authors.forename: Nicoline F
authors.initials: NF
authors.lastname: Tanih
authors.forename: Ezekiel
authors.initials: E
authors.lastname: Green
authors.forename: Roland N
authors.initials: RN
authors.lastname: Ndip
mesh_terms: D001431:Bacteriological Techniques; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D016972:Enterobacter cloacae / Q000187:drug effects* / Q000302:isolation & purification; D057140:Fast Foods / Q000382:microbiology*; D005516:Food Microbiology; D008087:Listeria / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D013019:South Africa