title: Comparative genomics study of multi-drug-resistance mechanisms in the antibiotic-resistant Streptococcus suis R61 strain.
abstract: BACKGROUND
  Streptococcus suis infections are a serious problem for both humans and pigs worldwide. The emergence and increasing prevalence of antibiotic-resistant S. suis strains pose significant clinical and societal challenges.
  
  
  RESULTS
  In our study, we sequenced one multi-drug-resistant S. suis strain, R61, and one S. suis strain, A7, which is fully sensitive to all tested antibiotics. Comparative genomic analysis revealed that the R61 strain is phylogenetically distinct from other S. suis strains, and the genome of R61 exhibits extreme levels of evolutionary plasticity with high levels of gene gain and loss. Our results indicate that the multi-drug-resistant strain R61 has evolved three main categories of resistance.
  
  
  CONCLUSIONS
  Comparative genomic analysis of S. suis strains with diverse drug-resistant phenotypes provided evidence that horizontal gene transfer is an important evolutionary force in shaping the genome of multi-drug-resistant strain R61. In this study, we discovered novel and previously unexamined mutations that are strong candidates for conferring drug resistance. We believe that these mutations will provide crucial clues for designing new drugs against this pathogen. In addition, our work provides a clear demonstration that the use of drugs has driven the emergence of the multi-drug-resistant strain R61.
authors.affiliation: Division of Animal Infectious Disease in the State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, People's Republic of China.
authors.forename: Pan
authors.initials: P
authors.lastname: Hu
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Anding
authors.initials: A
authors.lastname: Zhang
authors.forename: Jiayan
authors.initials: J
authors.lastname: Wu
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Hua
authors.forename: Jun
authors.initials: J
authors.lastname: Yu
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
authors.forename: Jingfa
authors.initials: J
authors.lastname: Xiao
authors.forename: Meilin
authors.initials: M
authors.lastname: Jin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002681:China; D024881:Drug Resistance, Bacterial; D018432:Drug Resistance, Multiple / Q000235:genetics*; D014644:Genetic Variation; D016680:Genome, Bacterial; D023281:Genomics; D006801:Humans; D008826:Microbial Sensitivity Tests; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D017011:Streptococcus suis / Q000235:genetics / Q000378:metabolism*; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents