Research of bacterial pathogens found in dogs with external otitis and its susceptibility profiles to several antimicrobial in Toledo city

Abstract

Chronic and overuse of antibiotics can lead to bacterial resistance, as a matter of extreme importance because its purpose is to help the clinic to identify the causative agent and appropriately treat the cases of external otitis diagnosed during the clinical routine. The aims of this study included the identification of the main microorganisms present in external otitis in dogs of Toledo-PR and its susceptibility to various antibiotics. Earwax samples were collected with sterile swabs from the external ear of 50 dogs treated at the Veterinary Hospital of PUCPR, campus Toledo, between August 2014 and May 2015. The microorganisms were cultured and identified according to the methods described in this paper, and the susceptibility to antimicrobial was assessed by the diffusion method on modified Kirby-Bauer disk. The antibiotics tested were as follows: gentamicin, neomycin, tobramycin, enrofloxacin, ciprofloxacin and norfloxacin. Regarding the microorganisms isolated from the 18 dogs whose samples showed bacterial growth, the most frequent was Staphylococcus pseudintermedius (55.5%), Staphylococcus epidermidis (16.6%), Pseudomonas aeruginosa (11.1%), Escherichia coli (11 1%) and Shigella sonnei (5.5%). Different resistance percentages were observed for each of the five bacteria found subjected to six antimicrobials. However, gentamicin and neomycin had high efficiency for all bacteria found. It can be concluded that the most frequently isolated causative agent was Staphylococcus pseudintermedius and the most effective antimicrobial against this were gentamicin, ciprofloxacin and norfloxacin. Canine otitis is an important disease in veterinary practice, thus, it is very important to know the agents associated and their susceptibility profiles in order to establish a targeted and effective treatment and prevent the spread of multi-resistant bacteria.