First Report of aac(6')-Ib and aac(6')-Ib-cr Variant Genes Associated with Mutations in gyrA Encoded Fluoroquinolone Resistance in Avian Campylobacter coli Strains Collected in Tunisia

Manel Gharbi; Mohammed Abdo Saghir Abbas; Safa Hamrouni; Abderrazak Maaroufi

doi:10.3390/ijms242216116

First Report of aac(6')-Ib and aac(6')-Ib-cr Variant Genes Associated with Mutations in gyrA Encoded Fluoroquinolone Resistance in Avian Campylobacter coli Strains Collected in Tunisia

Int J Mol Sci. 2023 Nov 9;24(22):16116. doi: 10.3390/ijms242216116.

Authors

Manel Gharbi¹, Mohammed Abdo Saghir Abbas^{2

3}, Safa Hamrouni¹, Abderrazak Maaroufi¹

Affiliations

¹ Group of Bacteriology and Biotechnology Development, Laboratory of Epidemiology and Veterinary Microbiology, Institut Pasteur de Tunis, University of Tunis El Manar (UTM), Tunis 1002, Tunisia.
² Unit of Vector Ecology, Pasteur Institute of Tunis, Tunis 1002, Tunisia.
³ University of Tunis El Manar (UTM), Tunis 1002, Tunisia.

Abstract

The aac(6')-Ib gene is the most widespread gene encoding aminoglycoside-modifying enzyme and conferring resistance to tobramycin, streptomycin and kanamycin. The variant aac(6')-Ib-cr gene confers resistance to both aminoglycosides and fluoroquinolones (FQ). A total of 132 Campylobacter isolates, including 91 C. jejuni and 41 C. coli, were selected from broiler hens isolates. The aac(6')-Ib gene was amplified using PCR and was subsequently digested with the BtsCI restriction enzyme to identify aac(6')-Ib-cr. Among these isolates, 31 out of 41 C. coli (75.6%) and 1 (0.98%) C. jejuni were positive for the aac(6')-Ib gene, which was identified as the aac(6')-Ib-cr variant in 10 (32.25%) C. coli isolates. This variant was correlated with mutations in gyrA (Thr-86-Ile), as well as resistance to FQs. This study is the first report in Tunisia on Campylobacter coli strains harboring both the aac(6')-Ib and aac(6')-Ib-cr variants. These genes were present in Campylobacter isolates exhibiting resistance to multiple antibiotics, which restricts the range of available treatments.

Keywords: Campylobacter; aac(6′)-Ib-cr; fluoroquinolone-resistance; phylogeny; poultry.

MeSH terms

Aminoglycosides / pharmacology
Animals
Anti-Bacterial Agents / pharmacology
Campylobacter coli* / genetics
Chickens
Drug Resistance, Bacterial / genetics
Escherichia coli / genetics
Female
Fluoroquinolones* / pharmacology
Microbial Sensitivity Tests
Mutation
Tunisia

Substances

Fluoroquinolones
Anti-Bacterial Agents
Aminoglycosides

Grants and funding

This work was financed by funding provided to the Laboratory of Epidemiology and Veterinary Microbiology (LR16IPT03) by the Tunisian Ministry of Higher Education and Scientific Research.