Isolation, characterization and antibiogram of bacteria associated with the mouth of pet dogs in Port Harcourt Metropolis

Abstract

This study aimed to isolate and determine the antibiogram of bacteria associated with the mouths of pet dogs in the Port Harcourt Metropolis. A total of five (5) swab samples were aseptically collected from the mouths of pet dogs across different locations in Port Harcourt and cultured on appropriate agar media using standard microbiological techniques. Bacterial isolation and enumeration were conducted using the spread plate method, while antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. The results showed that total heterotrophic bacterial counts ranged from 1.7 × 10⁵ to 5.9 × 10⁵ CFU/ml. Total coliform counts ranged from 1.0 × 10³ to 11.5 × 10³ CFU/ml, while total staphylococcal counts ranged from 1.5 × 10⁴ to 3.2 × 10⁴ CFU/ml. A total of twenty-seven (27) bacterial isolates belonging to six (6) genera were identified: Staphylococcus spp. (30%), Bacillus sp. (22%), Micrococcus sp. (4%), Pseudomonas sp. (11%), Klebsiella sp. (7%), and Escherichia coli (19%). Antibiotic susceptibility testing revealed that, among Gram-positive bacteria, Bacillus sp. exhibited 50% resistance to ceftazidime and 33% resistance to rifampicin, azithromycin, and ciprofloxacin but was susceptible to cefuroxime (66.7%), levofloxacin (100%), and gentamicin (100%). Staphylococcus spp. showed 66.7% resistance to ceftazidime but were susceptible to gentamicin (77.8%), rifampicin (88.9%), and levofloxacin (100%). For Gram-negative bacteria, E. coli exhibited 100% resistance to cefuroxime but showed 20% resistance to gentamicin and ciprofloxacin. Pseudomonas sp. was 100% resistant to cefuroxime but demonstrated 100% susceptibility to ofloxacin and ciprofloxacin. Given the observed cases of multidrug resistance in this study, it is recommended that pet dog owners administer antibiotics to their pets only under the prescription of a veterinary professional to prevent potential public health outbreaks.

Keywords: Antibiogram, characterization, bacteria, pet dogs, public health.