The Prevalence of Aeromonas Species Isolated from Raw and Locally Fermented Cow Milk from Four Local Government Areas of Plateau State, Nigeria

Abstract

Aeromonas species are non sporulating gram negative bacteria that are ubiquitous to the aquatic environment. Species such as Aeromonas hydrophila are pathogenic both to humans and animals causing gastroenteritis, peritonitis, endocarditis and meningitis. Milk with its high nutritional composition and neutral pH is a haven for microbial growth especially if not properly processed. Eight hundred milk samples comprising of raw milk (400) and locally fermented cow milk (“nono”) (400) were collected from Jos, Bukuru, Vom, Miango and Lamingo located within four local government areas of Plateau state. Raw milk samples were obtained from the farms and retailers while the locally fermented cow milk (“nono”) was purchased only from retailers. Each milk sample was collected in sterile well corked plastic containers, to prevent contamination in the course of transportation. The samples were examined for the presence of Aeromonas species using standard procedures. The isolates were subjected to cultural, biochemical, serological and phenotypic tests for the identification of Aeromonas species. The influence of seasonal variation on the prevalence of Aeromonas species in the milk samples was determined. Out of the 800 milk samples examined, 78 (9.75%) were positive for Aeromonas species. Among the two milk types investigated, raw milk had higher percentage prevalence, 53 (6.62%) than “nono” 25 (3.25%). The result of the effect of season on the prevalence of Aeromonas species isolated from milk, showed that a higher percentage prevalence of 59 (1.48%) of Aeromonas spp. was recorded in the two forms of milk during the wet season than during the dry season 19 (0.47%). Statistical analysis revealed a significant difference (p<0.05) (p=0.002) in the prevalence of the organism in both the raw and the fermented milk samples.