Phenotypic and Genotypic Methods used for Detection of Extended Spectrum ?-Lactamase Production in Sorbitol and Non-Sorbitol Fermenting E. coli Isolates Jointly Resistant to Cefotaxime and Ceftazidime from Vegetables Purchased from Keffi Main Market

Investigations were carried out on phenotypic and genotypic methods used for detection of extended spectrum -lactamase production sorbitol and non-sorbitol fermenting E. coli isolates jointly resistant to cefotaxime and ceftazidime. Vegetable samples were purchased from Keffi main market making a total of hundred (100). Twenty (20) each from pumpkin leaves (Telfaria occidentalis), lettuce (Lactuca sativa), spinach (Amaranthus hybridus), cabbage (Brassica oleracea) and carrot (Daucus carota)). Samples were packaged in sterile separate polythene bags and were immediately transported to Nasarawa state University Microbiology Laboratory for analyses. Sorbitol and non-sorbitol fermenting E. coli were isolated and identified from the samples using standard microbiological and biochemical methods. Antibiotic susceptibility test using disc diffusion methods as described by Clinical and Laboratory Standards Institute (CLSI) and the confirmatory test for extended spectrum -lactamase (ESBL) production in NSFE and SFE isolates jointly resistance to both cefotaxime and ceftazidime from vegetables were carried out using double disks synergy method. The molecular detection of ESBL genes such as TEM, SHV and CTX-M in NSFE and SFE isolates jointly resistant to both cefotaxime and ceftazidime were carried out using polymerase chain reaction (PCR) method. The detection of ESBL producing NSFE and SFE isolates jointly resistant to both cefotaxime and ceftazidime was 100.0 %. The order of occurrence of ESBL genes in NSFE were, SHV (100.0 %), TEM (12.5 %) and CTX-M (37.5 %). Sorbitol fermenting E. coli percentage occurrence of ESBL genes were, SHV (91.7 %), TEM (33.3 %) and CTX-M (33.3 %) respectively. The detection rate of E. coli was high in vegetables and most of the isolates were ESBL producers and the most common ESBL gene was SHV gene. Treatment of vegetables for eradication of pathogenic organisms before consumption is vital, so as to prevent infections arising from ingestion of pathogenic organisms.