Fishes are world widely consumed by all categories of works of life because of their
richness in protein, readily available and affordable by all. The basic nutrient of protein in
fish that is so important in man’s diet also attracted microorganisms for their growth and
multiplication. Meanwhile, the association of microorganisms in fishes depend on the
environment of culture and their proliferation due to inadequate storage facilities. The aim
of this study was focused on the isolation and identification of microorganisms from four
frozen fish species sold in the Ado Ekiti metropolis. Frozen fish samples of Scomber
scombrus (Atlantic Mackerel), Clupea harengus (Atlantic herring), Urophycis tenuis
(White hake or mud hake) and Trachurus trachurus (Atlantic horse mackerel) from two
markets in Ado Ekiti were microbiologically analyzed for possible microbial
contamination. On the fish samples, the total heterotrophic count (THC) was 3.5×104
–
5.6×104 CFU/g, total coliform count (TCC) was 2.4×104
– 5.1×104 CFU/g, total
Salmonella/Shigella count (TSSC) was 1.3×104
– 3.5×104 CFU/g, total Vibrio count
(TVC) was 1.1×104
– 2.3×104 CFU/g and total fungal count (TFC) was 1.3×103
– 2.3×103
Spore/g were analyzed by cultural methods. There were variations in microbial loads
among the fish species in the surveyed markets. The microorganisms identified with their
percentage occurrence were Bacillus cereus (11.54%), Streptococcus faecium (13.46%),
Alcaligenes faecalis (5.77%), Salmonella enterica serovar Typhi (5.77%), Micrococcus
luteus (9.62%), Vibrio cholerae (7.69%), Aerococcus viridans (3.85%), Pseudomonas
aeruginosa (7.69%), Xanthomonas fragariae (7.69%), Staphylococcus aureus (11.54%),
Clostridium butyricum (7.68%), Escherichia coli (7.69%), Aspergillus fumigatus
(11.11%), Aspergillus flavus (24.44%), Aspergillus clavatus (8.89%), Aspergillus
fishcheri (6.69%), Aspergillus terreus (8.89%), Mucor mucedo (17.78%), Penicillium
digitatum (13.33%) and Aspergillus parasiticus (8.89%). The results emphasized the
microbial contamination of the fishes. The results obtained could serve as an awareness to
consumers that microbial infection is possible from frozen fishes and as data for future
reference in epidemiology or outbreak of disease from eating frozen fish.
