Diversity of Ochrobactrum species in food animals, antibiotic resistance phenotypes and polymorphisms in the bla(OCH) gene

作者：Andrea Alonso Carla; Kwabugge Yakubu A; Anyanwu Madubuike U; Torres Carmen; Chah Kennedy F^*

来源：FEMS Microbiology Letters, 2017, 364(17): fnx178.

DOI：10.1093/femsle/fnx178

• non-fermenters
• Ochrobactrum species
• ampC
• bla(OCH)
• polymorphism
• food animals

Twenty-six lactose non-fermenting, oxidase, urease and citrate-positive Gram-negative rods, isolated from broiler chickens, pigs and cattle at slaughter, were subjected to the matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and 16S rDNA sequencing for identification. Susceptibility to 14 antimicrobials was determined by the disc diffusion method. Ochrobactrum isolates resistant to third-generation cephalosporins were PCR-screened for the presence of the Ochrobactrum anthropi ampC gene (bla(OCH)). A 547-bp internal segment of bla(OCH) in the Ochrobactrum spp isolates was amplified with a newly designed primer set, and a phylogenetic reconstruction based on the complete amino acid sequence of bla(OCH) obtained from nine Ochrobactrum strains in our collection and 20 O. anthropi available in the GenBank was undertaken. All the Ochrobactrum isolates were resistant to the expanded-spectrum beta-lactams and streptomycin. None of the isolates was resistant to imipenem while 41.7% to 50.0% of them were resistant to fluoroquinolones. The bla(OCH) gene was detected in 16 (66.7%) and 20 (83.3%) of the 24 Ochrobactrum isolates (O. intermedium/O. tritici species), using primers designed for O. anthropi and the newly designed primer set, respectively. Six bla(OCH) variants grouped into two divergent clusters were identified. This is the first report of the complete nucleotide sequence of the bla(OCH) gene in non-antropi Ochrobactrum species.

• 出版日期2017-9