Isolation of Listeria monocytogenes from Raw Meat Sold in Nasarawa State

Listeriosis is an emerging infection with major public health concerns worldwide because of occurrence of associated food-borne outbreak and significant risk of mortality and morbidity. This study aimed to isolate Listeria monocytogenes in raw meat samples in selected markets in Nasarawa State, determine the level of contamination, as well as the antibiogram of the isolates. A total of 60 samples of raw meat were collected from different animals, including 4 samples of cow meat, 4 samples of goat meat and 4 samples of chicken meat, from each market. In all, 60 raw meat samples were collected and analyzed microbiologically using the method of the Clinical and Laboratory Standards Institute (CLSI, 2009). Out of the 60 samples analyzed Listeria monocytogenes was detected in 32 samples, giving an overall prevalence of 53.5%. Sixteen out of 20 (80%) of cow meat samples, 10 out of 20 (50%) of goat meat samples, and 6 out of 20 (30%) of chicken meat samples were infected with Listeria monocytogenes. All the isolates were further subjected to biochemical analysis for the confirmation of the isolates. The results revealed the presence of Listeria monocytogenes in over 50% of the raw meat samples analyzed. The 53.5% prevalence was considered high and indicated the hazard linked to the consumption of the raw meats sold in Nasarawa State if not properly cooked. The susceptibility tests were also conducted using disc diffusion method. The results revealed that most of the isolates were resistant to most of the commonly used antibiotics such as Septrin, Ampiclox, Erythromycin, Zithromycin, Amoxillin, and Pefloxacin. However, some of the isolates were relatively sensitive to Ciprofloxacin, Sreptomycin, Gentamycin, and Rifampicin. The results signal a chemotherapeutic problem in case of any outbreak of the infection.