Microbiology -Scholarly Publications

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Browsing Microbiology -Scholarly Publications by Subject "Abattoir effluent"

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    Open Access
    HISTOPATHOLOGICAL CHANGES IN THE LIVER OF MICE CHALLENGED WITH Listeria monocytogenes IN SIX ZONES OF NIGERIA
    (Journal of Experimental Biology and Agricultural Sciences, 2013-11-15) Enurah, L. U.; Aboaba, O. O.; Nwachukwu, S.C.U.; Nwosuh, C. I.
    Fifty four strains of Listeria monocytogenes were isolated from fresh raw milk and abattoir effluent. Uniform distribution pattern of the isolates in the six zones of Nigeria viz Southwest, Southeast, Southsouth, Norhwest, Northeast and Northcentral is evidence that food contamination with this organism may be a source of foodborne outbreaks in Nigeria. Present study investigated the pathogenic nature of the strains. The pathogenic strains were isolated by culturing on 7% Sheep Blood Agar for evidence of haemolysis and were used to challenge three out of four groups of laboratory bred mice for pathogenicity test. The Group 1 mice were given 1ml of sterile distilled water orally and served as control, groups 2, 3 and 4 with 1.6 x 105cfu/ml orally, subcutaneously and intraperitoneally respectively. Experimental animals were successfully observed up to six days for clinical signs and possible mortality. All the infected mice that died were subjected to post-mortem examination which showed change with liver abscess with congested gall bladder containing purulent bile. Histopathology sections of the liver showed hepatocyte necrosis with infiltration of degenerative neutrophils, lymphocytes and few plasma cells compared to control. The study confirmed the presence of pathogenic strains of L. monocytogenes in all zones of Nigeria and their presence in the food may pose serious health hazards.