Microbial Contamination of Chicken Litter Manure and Antimicrobial Resistance Threat in an Urban Area Setting in Cameroon

Abstract

We conducted a pilot study to assess microbiological safety of chicken litter, an affordable organic and main fertilizer used in Cameroon and worldwide. A convenience sampling of 26 farms was done and a questionnaire was administered. Samples of litter were aseptically collected. <i>E. coli</i> and <i>Salmonella</i> spp. were isolated using CLSI standards. Antibiotic susceptibility testing was performed using the disc diffusion method and a micro broth dilution method for colistin. In broiler farms, 90% of participating farmers gave antibiotic prophylaxis. The prevalence of <i>E. coli</i> and <i>Salmonella</i> spp. was 59.1% and 15.5%, respectively. All <i>E. coli</i> isolates were multidrug resistant as well as 36.4% for <i>Salmonella</i> spp. No resistance was found against cefepime and imipenem. All <i>Salmonella</i> spp. tested were found sensitive to colistin while 26.7% of <i>E. coli</i> spp. were colistin resistant. Contamination of chicken litter may be an underestimated source of antimicrobial resistance (AMR) transmission towards animals, humans and the environment with multidrug resistant <i>E. coli</i> and <i>Salmonella</i> spp. This shows the need and opportunity for a One Health approach in AMR surveillance and control in Cameroon. Continued surveillance in chicken litter would enable monitoring of AMR risks and trends.