1. Beta-lactam resistance in Campylobacter coli and Campylobacter jejuni chicken isolates and the association between blaOXA-61 gene expression and the action of β-lactamase inhibitors
- Author
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Settimio Di Gregorio, Patrizia Casagrande Proietti, Maria Pia Franciosini, Gabriella Guelfi, Sara Bellucci, Silvio De Luca, and Camillo Pieramati
- Subjects
bla ,OXA-61, expression ,Campylobacter coli, Campylobacter jejuni, chicken, β-lactam resistance ,β-lactamase inhibitors ,chicken ,Campylobacter coli ,medicine.disease_cause ,Microbiology ,Campylobacter jejuni ,03 medical and health sciences ,Ampicillin ,Clavulanic acid ,expression ,polycyclic compounds ,medicine ,Nitrocefin ,030304 developmental biology ,0303 health sciences ,β-lactam resistance ,General Veterinary ,biology ,030306 microbiology ,OXA-61 ,Campylobacter ,General Medicine ,Amoxicillin ,biology.organism_classification ,Ticarcillin ,medicine.drug - Abstract
The objectives of this work were to evaluate β-lactamase-mediated β-lactam resistance in Campylobacter coli and Campylobacter jejuni isolates obtained from broiler chickens, expression of the blaOXA-61 gene in relation to β-lactamase production, and the possible association between blaOXA-61 gene expression and the action of inhibitors when combined with β-lactams. All strains were tested by disk diffusion and nitrocefin methods to assess antibiotic susceptibility and β-lactamase production, respectively. PCR and qPCR amplification were performed to evaluate qualitative and quantitative blaOXA-61 expression. Campylobacter spp. showed a high level of resistance to the most of antimicrobials tested. C. coli strains were ampicillin resistant and blaOXA-61 positive, and 59 out of 60 isolates were positive in the nitrocefin test. Twenty C. jejuni isolates were positive for blaOXA-61 and the nitrocefin test, although two isolates were ampicillin sensitive. Amoxicillin/clavulanic acid and ticarcillin/clavulanic acid do not seem to be active against C. coli, as 73.3 %, and 88.3 % of isolates were resistant to amoxicillin/clavulanic acid and ticarcillin/clavulanic acid, respectively. C. jejuni was not susceptible to amoxicillin/clavulanic acid, with 90 % of the strains showing resistance, whereas ticarcillin associated with clavulanic acid was significantly more efficient than ticarcillin alone (P < 0.01), with 90 % of the strains found to be susceptible. An association between blaOXA-61 expression and amoxicillin/clavulanic acid and ticarcillin/clavulanic acid resistance (P = 0.0001) was seen in C. coli, as well as in C. jejuni for ampicillin/sulbactam (P = 0.0001). Our results suggest that the clavulanic acid only shows an inhibitory effect on C. jejuni when combined with ticarcillin and that the inhibitors action is lower if the blaOXA-61 gene is highly expressed. more...
- Published
- 2020
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