African Journal of Fisheries Science ISSN 2375-0715 Vol. 8 (9), pp. 001-005, September, 2020. © International Scholars Journals

Full Length Research Paper

Isolation and identification of pathogenic bacteria associated with frozen mackerel fish (Scomber scombrus) in a humid tropical environment

Eze, E. I.1, Echezona, B. C.1* and Uzodinma, E. C.2

1Department of Crop Science, University of Nigeria, Nsukka, Nigeria.

2Department of Science Laboratory Technology, University of Nigeria, Nsukka, Nigeria.

Accepted 18 July, 2020

Abstract

Aquaculture products can harbour pathogenic bacteria which are part of the natural micro-flora of the environment. An in-vitro assay was carried out to ascertain and identify major bacterial contaminants of frozen fish, which hitherto had constituted an important dietary intake of the people of Nsukka, Nigeria. Fish samples collected were identified and bacterial load of the samples determined using agar plate method. Differentiations and characterizations of various isolates were based on biochemical reactions and gram-staining technique. Frozen mackerel fish (Scomber scombrus) was used for the study. In-vitro assay result revealed that the samples were predominantly contaminated by three bacteria species viz: Staphylococcus aureus, Escherichia coli and Lactobacillus plantarum. Incidences of the various isolates in the culture were found to be 60, 20 and 15%, respectively. The mean bacteria load of the isolates was 1.135 x 106 CFU g-1. This value was found to be markedly higher than the recommended public health and safety standard value of between 5.0 x 105 CFU g-1, approved by Nigerian National Agency for Drug Administration and Control (NAFDAC).

Key words: Isolation, identification, pathogenic bacteria, Scomber scombrus.