Antibiotic susceptibility of E. coli isolated from dry fish sold in local markets in Lusaka, Zambia.

Thumbnail Image
Nyimbili, Lillian
Journal Title
Journal ISSN
Volume Title
The University of Zambia
Escherichia coli has been known as one of the most common bacteria found in the intestinal tract of human and warm blooded animals. It is the major causative agent of serious infections and a mediator of drug resistance through the production of Extended Spectrum Beta-Lactamase enzymes(ESBL) that hydrolyse the beta-lactam ring on most of the beta lactam antibiotics including of penicillins, cephalosporins, and the monobactam aztreonam. These antimicrobial resistant strains have become a global public health challenge affecting both humans and domestic livestock. In Lusaka and worldwide Fish is considered as a universal protein source consumed by a larger population of people. Some people also favour consuming raw dry fish. The objective of this study was to determine the antibiotic susceptibility and presence of resistant genes of E. coli isolated from dry fish sold in open markets of Lusaka district. A total of 120 fish samples were collected between July 2018 and August 2018. The fish samples were subjected to bacteriological analysis. Of the 120 samples of fish analysed for E. Coli 69 percent were positive for E. coli and 31 percent were negative. The determination of E. coli as an ESBL producing organism was determined by growing the bacteria on MacConkey agar containing 2 mg/L of cefotaxime. Following culturing of E. coli on MacConkey agar containing 2 mg/L of cefotaxime 46 isolates 55.4 percent were detected as ESBL-producing. The E. coli isolates presumably identified to be ESBL producing following culture on MacCkonkey agar supplemented with cefotaxime were subjected to PCR. A total of 35 out of 46 isolates were tested for the presence of the blaCTXM gene and out of these 21 were positive for the blaCTXM gene. Of the samples subjected to antimicrobial sensitivity test suggested that ESBL producing E. coli isolates had conferred resistance to beta-lactum antibiotics and other common antimicrobial agents. The results obtained indicate the need for surveillance on the emergence of antimicrobial resistance in fish sold in open markets and improve the food safety and hygiene of this important source of protein.
Thesis of Master of Science One Health Food Safety