Antibiogram studies and extended spectrum beta-lactamase activity profile of Salmonella-like species isolated from poultry soil of the University of Uyo, Nigeria

ABSTRACT

Aims: The contribution of beta-lactamase activity of various bacterial species to the increased antimicrobial resistance being experienced worldwide is very scanty in the literature. This study was undertaken to investigate the antibiotic resistance pattern (antibiogram) of Salmonella-like bacterial species against some antibiotics, and the role beta-lactamase assumably produced by the Salmonella-like species, played in producing resistance. Methodology and Results: The antimicrobial sensitivity test and the beta-lactamase test of the Salmonella-like species were carried out using the methods of Kirby Bauer sensitivity test and the Double Disk Synergy test respectively, following isolation and identification of the organisms from poultry soil. Results revealed that Salmonella-like species were most highly resistant to Nalidixic acid (20, 66.66%), followed by Tetracycline (19, 63.33%), Cotrimoxazole, Amoxicillin and Augmentin (18, 60%), while the least was Ofloxacin (8, 26.66%). Multiple resistance of 4 or more antibiotics among the isolates from the soil outside the broilers enclosure was observed, while there was a significant difference (P <0.05) between poultry soil and control soil. This implied that the antibiotics with the highest resistance were most often applied to the birds, the droppings of which contaminated the soil. The resistant pattern of the isolates from the control soil is lower than that from the poultry soil. Extended Spectrum Beta-lactamase activity was expressed by all the isolates against Cefotazime, while the least resistance was against mostly Cefotazime. Conclusion, significance and impact of study It is concluded that there is a widespread Beta-lactamase activity causing antibiotic resistance by many species of bacteria as well as poultry Salmonella, thus exacerbating the global problem of antibiotic resistance and a serious health related implication for antibiotic use in poultry.