ISOLATION OF Vibrio AND Pseudomonas species FROM CRABS

ABSTRACT

Crabs are some of the most sought after food. Crab meat is rich in protein and low in fat. The aim of this study was to isolate and identify species of Vibrio and Pseudomonas and other bacteria from crabs and evaluate the activity of chitosan against the bacteria isolated. The crabs used for this study was purchased from Yanga market, Benin city of Edo state. Serial dilutions were carried out using the dilution factor of 10-4 and 10-2 respectively. The bacterial enumeration and isolation were carried out on Nutrient agar, Thiosulfate-CitrateBile Salts-Sucrose (TCBS) agar and Pseudomonas Cetrimide (PCA) agar using the Pour Plate method. Cultural, Morphological and Biochemical characterization were employed for the identification of bacterial isolates. Antibiotics Susceptibility profile of bacteria isolated was carried out using disc diffusion method. The activity of chitosan against the bacteria isolated was determined using the agar well diffusion assay. The total heterotrophic bacterial count of the crab samples ranged from 2.70±0.14 - 5.30±0.42 x 105 cfu/g. The total vibrio counts ranged from 3.20±0.24 - 5.00±0.85 x 103 cfu/g. The total pseudomonas counts ranged from 0.24±0.57 - 3.3±0.42 x 103 cfu /g. The bacteria isolated were species of Vibrio, Pseudomonas, Klebsiella, Bacillus, Enterococcus and Staphylococcus epidermidis. The antimicrobial susceptibility results showed that most isolates demonstrated resistance to the antibiotics used, suggesting the presence of multidrug resistant strains. The diameter of inhibitory zone of chitosan against isolates ranged from 2.00mm - 28.00mm. The bacteriology assessments revealed a notable presence of Vibrio and Pseudomonas species, raising concerns about potential foodborne illnesses risks. Additionally, the detected antibiotic resistance in these bacteria highlights the need for more effective antibiotic use in the seafood industry to safeguard both public health and the environment. However, proper cooking of crabs thoroughly is encouraged before consumption to reduce the outbreak of diseases.