Genotyping and Antibiotic Resistance Traits in Campylobacter jejuni and coli From Pigs and Wild Boars in Italy

Abstract

The present study investigated the genomic constitution and antimicrobial resistance (AMR) of 238 Campylobacter from pigs and wild boars in Italy between 2012 and 2019. Campylobacter strains were genotyped using multilocus sequence typing (MLST) and whole genome MLST (wgMLST), screened for antimicrobial resistance genes, and tested for phenotypic susceptibility to six different antibiotics. C. coli was detected in 98.31% and 91.66% of pigs and wild boars, while C. jejuni was isolated in the remaining cases. MLST assigned 73 STs and 13 STs in pigs and wild boars, respectively, including 44 novel STs. The predominant ST in pigs was ST-854 (12.36%), followed by ST-9264 (6.18%). ST-1055 and ST-1417 were predominant in wild boars (30% and 13.33%, respectively). The minimum spanning tree using 1,121 global MLST profiles showed specific Italian clusters and a clear separation between pig and wild boar profiles. The wgMLST confirmed the MLST clustering and revealed a high genetic diversity within C. coli population in Italy. Minimum inhibitory concentrations (MIC) of six antibiotics revealed higher resistance in pigs to ciprofloxacin, nalidixic acid, streptomycin and tetracycline, compared to wild boar. In contrast, most strains were susceptible to gentamicin. Worrying levels of multidrug resistance (MDR) were observed mostly in pig isolates. Molecular screening of AMR mechanisms revealed the predominance of gyrA T86I substitution among fluoroquinoloneand quinolone-resistant isolates, and the 23S rRNA A2075G mutation among macrolide-resistant isolates. Other resistance determinants were observed: (i) tet (O) gene was present among tetracycline-resistant isolates; (ii) rpsL and aph(3')-III genes conferring resistance to aminoglycosides, were identified only in streptomycin or gentamicin-resistant pig isolates; (iii) cmeA, cmeB, cmeC, cmeR genes responsible of pump efflux mechanisms, were observed in almost all the strains; (iv) OXA-61, encoding b-lactamase, was found in the half of the strains. Genotypic and phenotypic AMR profiling was fairly correlated for quinolones/fluoroquinolones. Campylobacter infection is common also in wild boar populations in Italy, suggesting that wild boars could be a reservoir of resistant and multi-resistant Campylobacter species, which may be of public health

Whole Resistome Analysis in Campylobacter jejuni and C. coli Genomes Available in Public Repositories

“…Gene names are colored according to the corresponding antimicrobial family (blue: beta-lactams, orange: tetracyclines, red: aminoglycosides, purple: quinolones, and green: MLSP). and C. coli isolates were observed among isolates from pigs than from wild boars in Italy (Marotta et al, 2020), where an important amount of multidrug-resistant strains were isolated from pigs, being the over-use of antibiotics the main cause of the spread of multidrug resistance among pig isolates.…”

“…Moreover, tetracycline is broadly employed in the poultry industry worldwide ( Van Boeckel et al, 2015 ), which could be an important reservoir for resistant strains. Furthermore, higher levels of resistant C. jejuni and C. coli isolates were observed among isolates from pigs than from wild boars in Italy ( Marotta et al, 2020 ), where an important amount of multidrug-resistant strains were isolated from pigs, being the over-use of antibiotics the main cause of the spread of multidrug resistance among pig isolates.…”

Genomic Relatedness, Antibiotic Resistance and Virulence Traits of Campylobacter jejuni HS19 Isolates From Cattle in China Indicate Pathogenic Potential

“…Notably, 62.3% of cattle isolates were predicted to have point mutations in gyrA (T86I), but all of the cattle isolates showed high levels of resistance to CIP. The discrepancies found between the predicted AMR genes and the observed phenotype could be explained by the existence of the efflux pump mechanisms or other unknown resistance mechanisms ( Marotta et al, 2020 ). Moreover, half of the cattle isolates showed resistance to ERY, whereas two clinical isolates showed resistance to ERY.…”

Genetic resistance to Campylobacter coli and Campylobacter jejuni in wild boar (Sus scrofa L.)

“…Wildlife can act as a reservoir for different infections, among which is Campylobacter; together with wild birds, small rodents and insects, wild boar may play this role, being a possible source of Campylobacter for farmed animals and humans (Marotta et al 2020). The percentage of wild boars from which it was possible to isolate different species of Campylobacter in feces or organs and tissues was variable in different geographical areas and in different researches (Atanassova et al 2008;Díaz-Sánchez et al 2013;Carbonero et al 2014;Navarro-Gonzalez et al 2014;Stella et al 2018), but the results confirm the role played by this wild mammal as carrier of the pathogen.…”