Antimicrobial resistance genotypes and phenotypes of Campylobacter jejuni isolated in Italy from humans, birds from wild and urban habitats, and poultry

• Published in: PloS one Vol. 14; no. 10; p. e0223804
• Main Authors: Marotta, Francesca, Garofolo, Giuliano, di Marcantonio, Lisa, Di Serafino, Gabriella, Neri, Diana, Romantini, Romina, Sacchini, Lorena, Alessiani, Alessandra, Di Donato, Guido, Nuvoloni, Roberta, Janowicz, Anna, Di Giannatale, Elisabetta
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 11-10-2019; Public Library of Science (PLoS)
• Subjects: Amides; Animal husbandry; Animals; Animals, Wild - microbiology; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotic resistance; Antibiotics; Antiinfectives and antibacterials; Antimicrobial agents; Antimicrobial resistance; Bacterial genetics; Bacterial Proteins - genetics; beta-Lactamases - genetics; Biology and Life Sciences; Birds; Birds - microbiology; Breakpoints; Campylobacter; Campylobacter jejuni; Campylobacter jejuni - drug effects; Campylobacter jejuni - genetics; Campylobacter jejuni - isolation & purification; Campylobacteriosis; Chickens; Chromosomes; Ciprofloxacin; Ciprofloxacin - pharmacology; Correlation; Diagnosis; Diarrhea; Drug resistance; Drug Resistance, Bacterial; Fluoroquinolones; Food production; Food products; Gastroenteritis; Gene mutation; Genes; Genetic polymorphisms; Genotypes; Habitats; Human populations; Humans; Husbandry; Infections; Italy; Laboratories; Medicine and Health Sciences; Microbial drug resistance; Mutation; Nalidixic acid; Nalidixic Acid - pharmacology; Nucleotides; Pathogens; Phenotypes; Poultry; Poultry - microbiology; Poultry farming; Risk factors; Single nucleotide polymorphisms; Single-nucleotide polymorphism; Species Specificity; Streptomycin; Tetracycline - pharmacology; Tetracyclines; Urban areas; Urban Renewal; Zoonoses; β-Lactam antibiotics; Italy
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0223804

Campylobacter jejuni, a common foodborne zoonotic pathogen, causes gastroenteritis worldwide and is increasingly resistant to antibiotics. We aimed to investigate the antimicrobial resistance (AMR) genotypes of C. jejuni isolated from humans, poultry and birds from wild and urban Italian habitats to identify correlations between phenotypic and genotypic AMR in the isolates. Altogether, 644 C. jejuni isolates from humans (51), poultry (526) and wild- and urban-habitat birds (67) were analysed. The resistance phenotypes of the isolates were determined using the microdilution method with EUCAST breakpoints, and AMR-associated genes and single nucleotide polymorphisms were obtained from a publicly available database. Antimicrobial susceptibility testing showed that C. jejuni isolates from poultry and humans were highly resistant to ciprofloxacin (85.55% and 76.47%, respectively), nalidixic acid (75.48% and 74.51%, respectively) and tetracycline (67.87% and 49.02%, respectively). Fewer isolates from the wild- and urban-habitat birds were resistant to tetracycline (19.40%), fluoroquinolones (13.43%), and quinolone and streptomycin (10.45%). We retrieved seven AMR genes (tet (O), cmeA, cmeB, cmeC, cmeR, blaOXA-61 and blaOXA-184) and gyrA-associated point mutations. Two major B-lactam genes called blaOXA-61 and blaOXA-184 were prevalent at 62.93% and 82.08% in the poultry and the other bird groups, respectively. Strong correlations between genotypic and phenotypic resistance were found for fluoroquinolones and tetracycline. Compared with the farmed chickens, the incidence of AMR in the C. jejuni isolates from the other bird groups was low, confirming that the food-production birds are much more exposed to antimicrobials. The improper and overuse of antibiotics in the human population and in animal husbandry has resulted in an increase in antibiotic-resistant infections, particularly fluoroquinolone resistant ones. Better understanding of the AMR mechanisms in C. jejuni is necessary to develop new strategies for improving AMR programs and provide the most appropriate therapies to human and veterinary populations.