OCCURRENCE OF LISTERIA SPECIES AND DETECTION OF LEAD AND CADMIUM IN FROZEN, SMOKED AND CANNED FISH IN KADUNA NORTH LOCAL GOVERNMENT, NIGERIA

OCCURRENCE OF LISTERIA SPECIES AND DETECTION OF LEAD AND CADMIUM IN FROZEN, SMOKED AND CANNED FISH IN KADUNA NORTH LOCAL GOVERNMENT, NIGERIA

Abstract

The Occurrence of Listeria species and detection of Lead and Cadmium metals in frozen, smoked and canned fish was investigated in Kaduna North Local Government Area of Nigeria. A total number of 180 fish samples comprising of 60 frozen, 60 smoked and 60 canned, were purchased from the fish vendors at the three major markets in Kaduna North L.G.A (Kawo Market, Abubakar Gumi market and Unguwar Rimi market). Sampling was done once weekly. Listeria species were isolated using pre-enrichment, selective medium and were identified by conventional biochemical tests and confirmed with Microbact ID-System. Heavy metal analysis was done using wet digestion method. Levels of lead and cadmium in digested fish samples were determined using Atomic Absorption Spectrophotometer (AAS). Results show that from the 180 samples, 24 (13.3%) were found to be contaminated with Listeria spp. Out of the 24 isolates, Microbact 12L –ID system showed that 9(37.5%) were L.grayi and 15(62.5%) L. ivanovii isolates respectively. Distribution of the occurrence of Listeria spp by sample type showed that smoked fish had the highest occurrence of 19 (31.7%) when compared with frozen fish which had 5 (8.3%) whereas canned fish had 0 (0%). Distribution of Listeria isolates by location showed that Unguwar Rimi market had the highest 15(25.0%) followed by Kawo market 5(8.3%) and the least contaminated was Abubakar Gumi market 4(6.6%). Antibiotic susceptibility testing showed thatListeria sppisolates were susceptible to gentamicin (the first choice antibiotic) used in the treatment of listeriosis. The sensitivity regimens were 24(100%) for Gentamicin as the most effective, followed by 22(92%) for Chloramphenicol, 21(88.0%) for Amoxicillin and 19(79%) for Oxacillin. Antimicrobial resistance pattern Erythromycin (ER) occurred in 5 of the 24Listeria species isolates. The distribution of maximum residue limit of the metals were cadmium 35(58.3%) in smoked fish, 23(38.3%) in frozen and 20(33.3%) in canned fish. Lead (Pb) had 47(78.3%) in smoked fish, 36(60%) in frozen fish and 42 (70%) in canned vii fish were above safe limit. There wasan association between occurrence of Listeria species and Lead and Cadmium levels in the fish sampled at p ≤ 0.05. The findings of this work showed a potential threat to health and safety of the public. It is therefore recommended that good hygienic practices be implemented during fish processing and handling. Additionally, use of antibiotics in both human and veterinary medicine should be appropriately monitored

OCCURRENCE OF LISTERIA SPECIES AND DETECTION OF LEAD AND CADMIUM IN FROZEN, SMOKED AND CANNED FISH IN KADUNA NORTH LOCAL GOVERNMENT, NIGERIA

Sharing is caring!