Plasmid Profile and Antibiotic Resistance Pattern of Bacteria from Abattoirs in Port Harcourt City, Nigeria

Several activities occur in abattoirs including receiving, slaughtering and sale of cattle for meat protein. In rearing of these animals, antibiotics and vaccines are incorporated as part of their meals as well as in the treatment of their infections. The regular use of antibiotics leading to the increased occurrence of antibiotic resistant organisms worldwide and also from abattoir samples, has prompted the determination of plasmid profile in these microorganisms as the plasmids act as a faster means of transmission of resistance genes. This study was thus aimed at determining the plasmid profile of multi-resistant microorganisms isolated from abattoirs. Several samples including swabs from the tables, cow blood, faecal matter and service water were collected from the Iwofe, Rumuodumaya and Trans-Amadi abattoirs located within Port Harcourt City. Antibiotics including Gentamicin (10 µg), Ofloxacin (5 µg), Augmentin (30 µg), Ceftazidime (30 µg), Cefuroxime (30 µg), Nitrofurantoin (300 µg), Cefixime (5 µg) and Ciprofloxacin (5 µg) were used to determine the sensitivity pattern of the isolated microorganims.The plasmid profile of the multiple antibiotic resistant microorganisms was determined using standard microbiological procedures. From the results, gram-positive isolates of the genera Bacillus and Staphylococcus exhibited 100% resistance to Cefuroxime, Ceftazidime and Augmentin while they exhibited 100% susceptibility to Ofloxacin. The gram negative isolates including those of the genus Escherichia, Pseudomonas and Proteus exhibited 100% resistance to Cefuroxime as well as 100% susceptibility to Ofloxacin. Strains of Escherichia coli, Bacillus amyloliquefaciens, Bacillus flexus and Klebsiella pneumoniae lacked plasmids while strains of Pseudomonas, Klebsiella, Escherichia, Staphylococcus aureus and Proteus mirabilis had at least one plasmid each. The absence of plasmids in some of these isolates, indicate that their resistance may be chromosome-mediated and not plasmid-mediated. The occurrence of plasmids in multi-resistant microorganisms, poses a serious public health threat as other susceptible organisms may become resistant to the regularly used antibiotics over time.