Antibiogram and Extended Spectrum Beta-Lactamase (ESBL) Profile of E. coli Species Isolated from Houseflies in Abakaliki Metropolis, Nigeria

This study determined the antibiogram and extended spectrum beta-lactamase (ESBL) production potentials of E. coli species isolated from houseflies from hospital, restaurant and fruit market environments in Abakaliki metropolis. A total of 150 samples (50 from each sample site) were analyzed using Standard Microbiological Methods. Antibiotic susceptibility profile of the isolates was determined using disc diffusion method. ESBL production was screened using Double Disc Synergy Test (DDST). A total of 12 isolates of E. coli were obtained. Of the 12 isolates, 6(50 %) were obtained from hospital while 3(25 %) each were respectively isolated from fruit market and restaurant environments. The antibiotic susceptibility and resistance patterns of E. coli isolated from the three environments (hospital, fruit market and restaurant) to different antibiotics showed that meropenem (100 %) had the highest activity while 100% resistance to ceftriaxone, ampicillin-sulbactam and cefoxitin were recorded. Resistance of the isolates from hospital to gentamicin up to 83.33 % was also recorded. Their susceptibility to other antibiotics used including nalixidic acid, ciprofloxacin, cefoxitin, ceftaxidime, gentamicin, ceftriaxone, sulfamethoxazoletrimetoprim, cefotaxime and ampicillin-sulbactam ranged from 16.67 % to 66.67 %. The extended spectrum beta-lactamase screening showed that none of the isolates tested positive. In conclusion, the study revealed that houseflies from hospital, fruit market and restaurant environments harbor multidrug resistant E. coli and that the multidrug resistance were not ESBL mediated.