Occurrence of Campylobacter jejuni and Campylobacter coli biotypes and antimicrobial susceptibility in healthy dogs in Southern Chile
Fernández, HeribertoOval, Andrés
Background: The thermotolerant species of Campylobacter, mainly C. jejuni and C. coli, are as important agents of human gastroenteritis worldwide, being a serious public health problem. They are widely distributed in the environment and the animal kingdom having as reservoirs a wide variety of animals, including dogs, which in turn can act as a source of infection for humans. The Campylobacter isolation rates found in dogs are heterogeneous with few available data in Latin American countries. However Campylobacter diarrhea in humans is a self-limited clinical process being antimicrobial treatment not always necessary, it is necessary to know their antimicrobial susceptibility/resistance profiles in clinical and reservoirs isolates, especially in C. jejuni and C. coli strains isolated from animals close to man as dogs are. The aims of this work were to determine the isolation frequency of C. jejuni and C. coli and their biotypes in healthy dogs and the susceptibility/resistance profiles of the isolated strains to six antimicrobial drugs. Materials, Methods & Results: Fecal samples from 141 healthy dogs were obtained, seeded into the TEC transport medium. In the laboratory, each sample was plated out on modified Skirrow medium and incubated at 42°C for 48 h under microaerobic conditions. The isolated strains were identified to species and biotype levels through their phenotypic characteristics using the API Campy® procedure (bioMérieux, Marcy/Etoile, France) and the method described by Lior, respectively. The antimicrobial susceptibility patterns to ampicillin, ciprofloxacin, chloramphenicol, erythromycin, gentamicin and tetracycline were determined by means of the E-test method, considering as the minimal inhibitory concentrations (MICs) the lowest antibiotic concentrations yielding no growth. Ampicillin resistant strains were tested for ß-lactamase production with the chromogenic cephalosporin test and the disc diffusion susceptibility test for ampicillin-sulbactam. The recovery rate of Campylobacter was 31.2% (C. jejuni 22.7%, C. coli 8.5%). Three of the four biotypes described for C. jejuni and the two described for C. coli were found being C. jejuni biotype I the most frequent one (53.1%). None of the strains showed resistance to chloramphenicol, erythromycin, gentamicin and tetracycline. Resistant strains were found for ciprofloxacin (6 strains, 13.9%) and ampicillin (4 strains, 9.1%). All the ampicillin resistant strains were found to be ß-lactamase producers. Discussion: The Campylobacter isolation rate (31.2%) found is not negligible. It may provide an epidemiological insight about the risk of zoonotic infection for individuals maintaining contact with dogs, especially for children. Direct contact with pets is a risk factor for acquiring campylobacteriosis, which was also observed in Latin-American countries. Ampicillin resistance is related to ß-lactamase production and was reported in different countries, including Chile. Campylobacter resistance to quinolones has been increasingly reported in strains of human and animal origin, especially from animals related to husbandry. The ciprofloxacin resistant strains found in this study probably could be a reflection of their spread to human pets. Because dogs have been identified as a potential source of human Campylobacter infections, exposure to animals carrying fluoroquinolone-resistant microorganisms could be a risk factor for acquiring this kind of strains.
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