Determinants of Antimicrobial Use, and Their Resistance Patterns of Selected Enterobacteriaceae Isolated From Commercial Poultry Production Systems in Kiambu County, Kenya

Abstract

Commercial poultry production is an important farming enterprise in most parts of Kenya. The treatment of enteric infections in animals has been complicated through development of antimicrobial-resistant microbes. Occurrence of Multiple forms of drug resistance patterns has rendered chemotherapy drugs less effective in management of microbial infection. Multidrugresistant Extended-Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae places great threat towards public health by raising morbidity and mortality particularly in developing countries. Accurate statistics on the frequency and mechanism of antibiotic resistance development in enteric micro-organisms isolated from poultry and persons in Kenya is scarce. This current study determined the extent of antimicrobial use, and resistance patterns in selected Enterobacteriaceae isolated from commercial poultry production systems in Kiambu County, Kenya. A descriptive cross-sectional study was conducted on commercial poultry production systems of Kiambu County to ascertain the knowledge level, attitudes, and practices on antibiotics use in addition to their resistant patterns on selected Enterobacteraceae species. One hundred and fifty six commercial poultry farmers were purposively selected from the following subcounties; Ruiru (n=33), Juja (n=20), Gatundu North (n=20), Gatundu South (n=19), Thika (n=27) and Kikuyu (n=37) respectively. One hundred and fifty-six (n=156) semi-structured questionnaires imprinted in a mobile Open data kit were administered to capture the knowledge level, attitudes, and practices on antimicrobial usage in commercial poultry production systems of Kiambu County. A total of 437 fecal samples (cloacal swabs (n=365), and Human stool (n=72)) were collected, followed by bacterial isolation, confirmation, antibiotics susceptibility tests, and molecular detection of ESBLs genes and Quinolones resistance (QNRs) were detected using Polymerase chain reaction (PCR) methods. Out of 156 commercial poultry farmers who participated in this study, females accounted for (64%) with 51% of them keeping layers between 50-500 birds as medium-scale farmers. Sixty-one percent (61%) of the farmers were 45 years and above, and they had obtained a secondary level of education (34%). Sixty seven percent (67%) of the farmers obtain antibiotics through self-prescription/personal experience from the drug shops. Farmers identified lack of enough veterinary officers (77%) and consultation services (72%) as key challenges in poultry production system. Sixty three percent (63%) of the respondents, indicated tetracycline as the most commonly used antibiotic in their farms, with oxytetracyclines subtype (85%) being the most preferred. Also amoxicillin (63%) was equally preferred by farmers with amoxi (88%) sub-types being the most preferred, xxi respectively. Nearness to veterinary services significantly (P<0.05) contributed to the use of antibiotics agents. Additionally, the area of residence, type of production, number of years in farming, and average number of birds kept also significantly (P<0.05) influenced the level of knowledge and practice on antimicrobial usage. Out of 437 fecal and stool samples collected, 591 (Cloacal isolates=544; human isolates= 47) isolates were recovered, with E.coli (48.9%) being the most frequently identified, followed by Shigella spp. (18.8%), Salmonella spp. (18.3%), and Klebsiella spp. (14.0%).There was a great occurrence of multiple resistance among isolates especially towards sulfamethoxazole (79%), trimethoprim (71%), and tetracyclines (59%), respectively. Additionally, the isolates showed the highest rate of susceptibility against cefuroxime (94%), gentamicin (93%), ceftriaxone (91%), cefepime (89%), cefotaxime (85%), ceftazidime (84%), and chloramphenicol (77%), respectively. Out of the isolates (n=78) collected with potential ESBLs production, only 66 (84%) tested positive for the target genes with the utmost detected ESBL genetic factor from the isolates being blaOXA (n=20; 26%), followed by blaTEM (n=16, 21%), with the majority of them detected in Escherichia coli. In all the four enteric's bacteria-type isolates tested, the blaCTXM gene was detected. Three (n=3) Salmonella, and E.coli spp respectively harbored all the five tested antimicrobial resistance (AMR) gene types. The blaTEM, blaOXA, blaSHV, and QnrS genes were not detected from Klebsiella and Shigella spps. Additionally, most of the AMR gene co-carriage was detected in both E.coli and Salmonella spps as follows blaTEM+blaOXA (n=4); blaTEM+QnrS (n=3); blaTEM+blaOXA+Qnrs (n=3), concurrently. It was concluded that both fecal and stool materials from commercial poultry and humans can be a reservoir of multi-drug resistance enterics. This is a potential route of spreading out resistance genes amongst livestock and Humans, which pose a great danger to public health of Kiambu County residence. There is also need to strengthen antimicrobial surveillance and monitoring strategies at County level. It was recommended that the results of the current study be used in formulating strategies and informed decisions in combating antibiotic resistance and irrational usage of antibiotics in commercial poultry production in Kiambu County and other areas with similar poultry production systems in Kenya.