Detection of Enterotoxin Production by Staphylococcus Species in Fresh Raw Milk Samples From Large Mechanized Dairy Farms and Small Holder Dairy Farms in Kaduna and Zaria.

Abstract Staphylococcus species are considered the primary and most lethal agents that cause mastitis; they are also an important pathogens of public health concern because of their production of enterotoxins which causes staphylococcal food poisoning. A total of 592 quarter milk samples, 30 bulk milk samples and 27 swab samples of milkers hands were examined from 12 farms (Both mechanized and small holder farms) in Kaduna as well as in Zaria. The prevalence of subclinical mastitis from postive California Mastitis Test (≥+) was 24.5%. The mean Staphylococcal count was 4.2 log10 cfu/ml. One hundred and three (103) Staphyloccocal isolates that were Gram positive and catalase positive were identified biochemically, out of which the identities of 51 was confirmed using the Microbact Microgen Kit, from this number, 25 selected isolates were tested for enterotoxin production using the Staphylococcal Enterotoxin Reverse Passive Latex Agglutination (SET-RPLA) kit. From the number tested, 60% were found to produce one or more Staphylococcal Enterotoxins (SEs). Eight (32%) of the isolates produced SEA, 3 (12%) produced SEB. None of the isolates produced SEC and SED but 1 (4%) produced SE (ABC). PCR analysis to detect the Enterotoxin genes showed that only 5 SEA genes were present out of the 8 SEA producers and 2 of SEB genes were detected in the 3 SEB producers tested. At the end, it was recommended that consumption of raw, unpasteurized cow milk should be avoided by the people in order to prevent the risk of Staphylococcal Enterotoxin food poisoning.