B. A. Omogbai

The consumption of bivalves, such as mussels, clams, and oysters, is widespread across the globe, particularly in Coastal regions. Due to the natural habitat of bivalves and feeding habitat, there is a high possibility of the meat being contaminated with microorganisms and toxic elements. Hence, this research investigated the prevalence of Listeria and Vibriospecies, and polycyclic aromatic hydrocarbons (PAHs) in bivalves (Ergeria radiata). A total of three hundred (300) edible bivalves (Ergeria radiata) were obtained during March 2023 to February 2024 from the Ekowe community Coastal waters and from wet markets (Swali
and Opolo) using sterile containers. Bacteria were enumerated using standard microbiological procedures. Isolates of Vibrio and Listeria were identified by the polymerase chain reaction (PCR) technique. Antibiotic susceptibility of the isolates was determinedusingKirby-Bauer disc diffusion method. Plasmid profiling and curing of Vibrio and Listeria isolates were determined by standard methods. Proximate analysis of Ergeriaradiata was determined using standard analytical chemical methods. Mineral and heavy metal compositions were determined by Atomic Absorption Spectroscopy (AAS), while Na and K were analyzed by flame photometry. Polycyclic aromatic hydrocarbons were analyzed by Gas Chromatography-Mass Spectrometry (GC/MS). Standard methods were used to determine the physicochemical properties of the Coastal water samples. The data obtained were statistically analyzed using one-way analysis of variance (ANOVA) using SPSS version 20.0. Duncan multiple range test was used to separate the means at p<0.05 significant differences. The results of this study revealed that higher bacterial counts were observed in thewet season compared to the dry season. The total heterotrophic bacterial counts for the wet season ranged from 20.48 ± 1.62x 10 5 cfu/g - 30.06 ± 1.63x 10 5 cfu/g, while for dry season it rangedfrom 10.88 ± 1.09 x 105 cfu/g – 18.18 ± 1.10 x10
5 cfu/g. The Vibrio counts for wet seasonranged from 16.82 ± 1.17 x 10 5 cfu/g - 19.90 ± 1.27 x 10 5 cfu/, while for dry season it rangedfrom 9.96 ± 0.95 x 10 5 cfu/g – 13.58 ± 1.12 x 10
5 cfu/g. Listeria counts for wet seasonranged from 8 .08 ± 0.50 x 10 5 cfu/g – 11.52 ± 0.76 x 10 5 cfu/g, while for dry seasonit
ranged from 6.12 ± 0.67 x10 5 cfu/g – 9.72 ± 0.8 x 10 5 cfu/g - 9.72 ± 0.81 x 10 5 cfu/g.TheVibrio species isolated were Vibrio parahaemolyticus, Vibrio cholerae, Vibrio vulnificus, and Vibrio fluvialis with the accession numbers PP832852, PP382853, PP832854 and PP832855, respectively. Listeria species isolated were Listeria innocua PP832856, Listeria monocytogenes PP832857, and Listeria ivanovii PP328560. The hlyA virulence gene was detected in all the Listeria species for both wet and dry season. The virulence gene ctxAwasnot detected in Vibrio parahaemolyticus for wet season, but was detected in dry season. Thepenicillin binding protein (pbp2b) resistant gene was detected in all Listeria species. Theaph(2")-If antimicrobial resistant gene was detected in Vibrio parahaemolyticus andVibrofluvialis for wet season, while in dry season, it was detected in all the Vibrio species. Therewas no seasonal variation in the values obtained for proximate composition, minerals. andheavy metal content. Protein ranged from 7.42 ± 0.72 % - 7.59 ± 0.6 %, fat (0.74 ±0.05%-0.77± 0.9%), K (510 ± 0.52 mg/kg - 520 ± 0.13 mg/kg), and Pb (0.03 ± 0.01 mg/kg –0.047±0.16 mg/kg). Polycyclic aromatic hydrocarbons (PAHs) concentration of Ergeria sradiatawas low for both wet and dry season, and was below the permissible limit of 200 ppmset byWorld Health Organization (WHO). The physicochemical properties of the Coastal watersforwet season exceeded the permissible limit set by WHO. Bivalve (Ergeria radiata), although nutritionally rich, harbors potentially pathogenic bacteria of public health concern, particularly when they are consumed raw or not properly cooked.

Allium fistulosum (Spring onions) also known as scallions or green onions are vegetables derived from various species of the genus Allium. The leaves and bulbs which are used as vegetables can either be eaten raw or cooked, chopped into other dishes and used as garnishes. These onions which require cultivation temperature ranging from 10o C to 22o C and irrigation during dry periods can be contaminated by various types of bacteria. This study therefore investigated the antibiotic resistance profile of some food-borne bacteria isolates from spring onions.Twenty-four (24) samples of spring onions were obtained from vendors across eight markets in Benin metropolis. Ten grams (10g) of spring onions was blended with a high speed homogenizer and the homogenate was serially diluted using peptone water. Standard microbiological methods were used to evaluate the bacteria load present in the samples. The bacteria were identified using both phenotypic and molecular techniques with the aid of polymerase chain reaction (PCR). Antibiotic sensitivity test was carried out using Kirby￾Bauer disk diffusion method on Mueller Hinton agar. The results were interpreted by measuring the zones of inhibition around each antibiotic disc in millimeters. Isolates that resisted one or more antibiotics from three or more distinct antibiotics classes were classified as multidrug resistant (MDR) isolates. The multidrug resistant (MDR) food-borne bacterial isolates were then subjected to plasmid profiling.The heterotrophic bacterial count showed that spring onions from Oba market had the highest
count (8.71 ±1.80× 106cfu/g) while Oluku had the lowest (5.71±1.50× 106cfu/g). The bacteria isolates were Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus cereus, Proteus vulgaris and Serratia marcescens. The percentage occurrence of isolates ranged from 25% to 100% with Bacillus cereus having the highest and Enterobacter aerogenes the lowest. Serratia marcescens was resistant to all antibiotics used while Enterobacter aerogenes was the least resistant. The multiple antibiotic resistance index (MAR I) ranged from 0.25 to 1.0 for all bacteria isolated. Two of the isolates (Klebsiella pneumoniae and Proteus vulgaris) had plasmids of size 1000 base pair (1.0 Kb). The presence of these food-borne bacterial isolates could be due to use of contaminated irrigation water, improper handling during harvesting and point of sales. The bacteria isolates which were multi-drug resistant and plasmid mediated pose a grave threat to publichealth. Spring onions should therefore be properly cooked prior to consumption

This research was undertaken in order to investigate the bacteria associated with locally processed juices and screen for their sensitivity to antibiotics and chitosan. Tigernut milk, zobo and ginger lemon juice samples were purchased from three (3) different shopping malls in Benin City and transported to the laboratory for bacteriological analysis using pour plate isolation method. Susceptibility of bacteria to antibiotics was carried out using disc diffusion method. Antimicrobial activity of chitosan against isolated organisms was carried out using agar well diffusion method. Total bacterial count on nutrient agar ranged from 13.5×10 3cfu/ml for zobo drink (ZN) to 114×10 3cfu/ml for tigernut milk (TNMFJ). On eosin methylene blue agar, total bacterial count ranged from 5×10 3cfu/ml for zobo drink (ZN) to 52×10 3cfu/ml for tigernut milk (TNMN). Organisms isolated include Lactobacillus fermentii, Staphylococcus spp and Salmonella spp. While Lactobacillus fermentii was the least prevalent (60%), Salmonella spp was the most prevalent (100%). The pH ranged from 3.56 in zobo drink (ZN) to 4.78 in tigernut milk (TNMFJ). Tigernut milk (TNMF) had the highest value of total dissolved solids (2.27mg/ml) while ginger lemon juice (GLN) had the least (0.10mg/ml). The titratable acidity of juice samples ranged from 0.02mg/L in zobo juice (ZN) and ginger lemon juice (GLN) to 0.48mg/L in tigernut milk (TNMFJ). The bacterial isolates showed various levels of sensitivity and resistance to a variety of ten (10) antibiotics. Antimicrobial effects of chitosan against Staphylococcus spp and Salmonella spp showed that Salmonella spp was more susceptible to chitosan at a concentration of 25mg/ml. The results indicate that locally processed juices were contaminated with bacterial isolates and should be subjected to good manufacturing practice (GMP). The inhibitory effect of chisotan show it as a potential preservative in food.