Risk Factors for Listeria monocytogenes Contamination in Nigerian Poultry Flock Environment

Abstract

Poultry production is rising in Nigeria with attendant health concerns to the farmers and the surrounding environments. Microbial contamination from the poultry environments presents with health risks to the poultry. The aim of this study was to identify potential risk factors for Listeria monocytogenes (L. monocytogenes) contamination in Nigerian poultry production environment. A total of 71 flocks of poultry farms randomly selected under different settings were investigated for the presence of L. monocytogenes contamination. Two hundred and eighty-four swab samples were taken from feed (n=71), water (n=71), dust (n=71) and workers’ boots (n=71) and cultured for L. monocytogenes isolation using Brilliance SelecTM tive Listeria Agar and microbial load count with Nutrient Agar. Further identification was done using microscopic and biochemical characterization. Bivariate and logistic regression models were used to assess the association between management practices and the risk of L. monocytogenes contamination of the flocks. The prevalence of L. monocytogenes-positive flocks was 100.0% with overall prevalence of 90.1% based on samples. The prevalence was highest in feed (95.8%) and least in dust swabs (84.5%). A significant association was observed between L. monocytogenes contamination and farm size (p=0.05), but not with feed type (p=0.34), management (p=0.54) and biosecurity type (p=0.74). We recommend stricter hygienic practices especially as farm size increases and when processing and handling poultry feed as feed contamination might be a critical point in the control of L. monocytogenes contamination of other materials and in poultry farms.