New Characterization of Multi-Drug Resistance of Streptococcus suis and Biofilm Formation from Swine in Heilongjiang Province of China.

The aim of this study was to investigate the antimicrobial resistance profiles and genotypes of in Heilongjiang Province, China. A total of 29 were isolated from 332 samples collected from 6 pig farms. The results showed that serotypes 2, 4 and 9 were prevalent, and all the clinical isolates were resistant to at least two antibacterial drugs. The most resisted drugs were macrolides, and the least resisted drugs were fluoroquinolones. Resistant genes and were highly distributed among the isolates, with the detection rates of 79.31% and 75.86%. The formation of biofilm could be observed in all the isolated , among which D-1, LL-1 and LL-3 strains formed stronger biofilm structure than other strains. The results indicate that in Heilongjiang Province presents a multi-drug resistance to commonly used antimicrobial drugs, which was caused by the same target gene, the dissemination of drug resistance genes, and bacterial biofilm.