Antimicrobial resistance genotypes and phenotypes of Campylobacter coli isolated from different sources over a 16-year period in Brazil

Abstract

ABSTRACT: Objectives: This study aimed to identify antimicrobial resistance genotypes in 63 Campylobacter coli strains isolated from humans (12), animals (21), the environment (20), and food (10) in Brazil using whole genome sequencing (WGS) tools, comparing them with results obtained by antimicrobial susceptibility testing (AST) against some important antimicrobials in clinical use. Methods: Phenotypic resistance profiles were determined by minimal inhibitory concentrations and the disk diffusion technique. The prediction of the resistance genes was performed using ABRicate v.0.8 and the Resistance Gene Identifier software of the CARD. Results: The percentage of C. coli strains phenotypically resistant to antimicrobials were: ampicillin, 44.4%; doxycycline, 20.6%; tetracycline, 20.6%; ciprofloxacin, 12.7%; nalidixic acid, 12.7%; streptomycin, 6.3%; erythromycin, 4.8%; and gentamicin, 1.6%. The genes blaOXA-605 / blaOXA-61, tet(O), cmeB, aadE-Cc, aph (3 ') – IIIa, sat4 and aad9 were detected in 54%, 22.2%, 9.5%,6.3%, 1.6%, 1.6%, and 1.6% strains, respectively. Mutations T86I in the QRDR region of gyrA were detected in 8 (12.7%) strains. The agreement between AST and WGS was 100%, 92.9%, 82.4%, and 80% for quinolones, tetracycline, β-lactam, and aminoglycoside classes, respectively. Conclusions: The rates of C. coli strains resistant to β- lactams and quinolones may represent a public health concern. The partial agreement between AST and WGS shows that improvement in antibiotic resistance databases may be required to minimize this discrepancy observed in some antimicrobial classes and to become an acceptable tool to both clinical microbiologists and regulatory agencies.

Keywords

• Campylobacter coli
• Antimicrobial resistance profiles
• Whole genome sequencing
• Antimicrobial susceptibility testing