Molecular characterization of antimicrobial resistance in Klebsiella pneumoniae isolated from Brazilian dairy herds

Author(s)

Nobrega, Diego Borin ^{[1, 2]} ; Calarga, Aline Parolin ^[2] ; Nascimento, Leandro Costa ^[3] ; Chande Vasconcelos, Carla Gasparotto ^[4] ; de Lima, Eliane Martins ^[4] ; Langoni, Helio ^[5] ; Brocchi, Marcelo ^[2]

Affiliation

^[1] Univ Guelph, Ontario Vet Coll, Dept Populat Med, Guelph, ON N1G 2W1 - Canada

^[2] Univ Estadual Campinas, Inst Biol, Dept Genet Evolut Microbiol & Immunol, UNICAMP, BR-13083650 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, Cent Lab High Performance Technol LaCTAD, UNICAMP, BR-13083886 Campinas, SP - Brazil

^[4] VidaVet Vet Anal Lab, BR-18602060 Botucatu, SP - Brazil

^[5] Sao Paulo State Univ UNESP, Dept Vet Hyg & Publ Hlth, BR-16618681 Botucatu, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF DAIRY SCIENCE; v. 104, n. 6, p. 7210-7224, JUN 2021.
• Web of Science Citations: 0

Abstract

In this observational study, phenotypic and genotypic patterns of antimicrobial resistance (AMR) in Klebsiella pneumoniae isolated from intramammary infections, clinical mastitis, fresh feces, rectal swabs, animal hindlimbs, and bulk tank milk samples from Brazilian dairy herds were investigated. In addition, we identified specific genetic variants present among extended-spectrum beta-lactamase (ESBL) producers. We obtained 169 isolates of K. pneumoniae from 2009 to 2011 on 24 Brazilian dairy farms located in 4 Brazilian states. The AMR profile of all isolates was determined using disk-diffusion assays. The antimicrobial panel included drugs commonly used as mastitis treatment in Brazilian dairy herds (gentamicin, cephalosporins, sulfamethoxazole-trimethoprim, tetracycline) as well as antimicrobials of critical importance for human health (meropenem, ceftazidime, fluoroquinolones). The K. pneumoniae isolates resistant to tetracycline, fluoroquinolones, sulfamethoxazole-trimethoprim, or chloramphenicol were screened for presence of drug-specific AMR genes {[}tet, qnr, aac(6')-Ib, floR, catA2, cm1A, dfr, sul] using PCR. In addition, we identified ESBL genes present among ESBL-producers by using whole genome sequencing. Genomes were assembled and annotated, and patterns of AMR genes were investigated. Resistance was commonly detected against tetracycline (22.5% of all isolates), streptomycin (20.7%), and sulfamethoxazole-trimethoprim (9.5%). Antimicrobial resistance rates were higher in K. pneumoniae isolated from intramammary infections in comparison with isolates from feces (19.2 and 0% of multidrug resistance in intramammary and fecal isolates, respectively). In contrast, no difference in AMR rates was observed when contrasting hind limbs and isolates from intramammary infections. The genes tetA, sul2, and floR were the most frequently observed AMR genes in K. pneumoniae resistant to tetracycline, sulfamethoxazole-trimethoprim, and chloramphenicol, respectively. The tetA gene was present exclusively in isolates from milk. The genes bla(CTX-M8) and bla(SHV-108) were present in 3 ESBL-producing K. pneumoniae, including an isolate from bulk tank milk. The 3 isolates were of sequence type 281 and had similar mobile genetic elements and virulence genes. Our study reinforced the epidemiological importance and dissemination of bla(CTX-M-8) pST114 plasmid in food-producing animals in Brazil. (AU)

• FAPESP's process: 13/11880-1 - Antimicrobial resistance profile in Salmonella enterica isolated from poultry and detection of invA gene in serovars Senftenberg and Saint Paul
• Grantee: Aline Parolin Calarga
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 12/10608-3 - Phenotypic and genotypic profile of antimicrobial resistance in Klebsiella pneumoniae, Salmonella enterica and coagulase-negative Staphylococcus
• Grantee: Diego Borin Nobrega
• Support Opportunities: Scholarships in Brazil - Doctorate