Molecular Characterisation of Bacteria Isolated from Various Part of Chicken (Gallus gallus domestica) Meat

Aims: To investigate the types of bacteria found in the different parts of Chicken meat using biochemical and molecular techniques.

Study Design: Poultry birds were bought and processed in the respective markets by the butchers. Four parts of the poultry meat were minced and placed in sterile bottles which were taken to the lab for analysis. The control was bought and processed in the laboratory.

Place and Duration of Study: The Mile three and Mile one markets which are amongst the major markets in Port Harcourt metropolis, Rivers State, Nigeria were the area under study. The study duration was for three months.

Methodology: Ten gram of four parts (intestine, gizzard, muscle and skin) each was weighed and transferred into test tubes containing 90ml sterile normal saline. Subsequent 10-fold serial dilution was carried out and aliquots of preferred dilutions were inoculated unto Nutrient and MacConkey agar (TM media, India) plates. Incubation for 24 hours at 37°C followed. Resulting colonies were enumerated and distinct colonies were subcultured to get pure isolates followed by biochemical tests to identify the isolates. The boiling method of extraction was used in extracting the DNA of the various isolates. rRNA genes of the isolates were amplified using the 27F and 1492R universal primers on a ABI 9700 Applied Biosystems thermal cycler at a final volume of 25 µl for 35 cycles.

Results: The total heterotrophic load of the skin ranged from 0.2×108 to 5.5×108 Cfu/g. the bacterial load of the muscle, intestine and gizzard ranged from 0.0×108 to 1.0×108 Cfu/g; 1.2×108 to 2.9×108 Cfu/g and 1.7×108 to 2.0×108 Cfu/g. The coliform load of the skin ranged from 0.2×105 to 2.2×105 Cfu/g, while the total coliform of the muscle, intestine and gizzard ranged from 0.1×105 to 1.9×105 Cfu/g, 1.1×105 to 1.5×105 Cfu/g and 0.2×105 to 2.0×105 Cfu/g respectively. Nine bacteria genera which include Salmonella, Shigella, Vibrio, Enterococcus, Staphylococcus, Chryseobacterium, Aeromonas, Acinetobacter and Escherichia species were isolated and identified.

Conclusion: The bacteria identified in this study could be pathogenic if foods are not properly prepared. Thus, chicken meats should be properly processed to avoid cross contamination.