Dissemination and characterization of Stenotrophomonas maltophilia isolates from Dairy Cows in Northeast China.

This work investigated the genetic relationship among strains in fecal samples from dairy cows in northeast China and identified the dominant β-lactamase genotype. One hundred and six samples were collected from two randomly selected cow farms in northeast China, and the isolates were identified with MALDI-TOF/MS. Whole-genome sequencing was conducted using Illumina HiSeq 4000-PE150 platform (Illumina, Inc., USA). The antimicrobial resistance genes were detected using CGE services. The phylogenetic analysis of strains was performed by Roary and MEGA X. In total, 24 isolates were isolated. The results of resistome analysis showed all strains carrying gene, which was the only β-lactamase genotype. In addition, the aminoglycoside resistance genes and were found. The phylogenetic tree indicated the clonal diversity of in these two regions and the clonal relatedness of the strains from these regions. This study first investigated the dissemination and characterization of isolates from dairy cows in northeast China and provided evidence of the potential transmission between two provinces. Furthermore, it indicated was the most prevalent genotype of β-lactamase in these regions.