title: A novel multi-locus sequence typing (MLST) protocol for Leuconostoc lactis isolates from traditional dairy products in China and Mongolia.
abstract: BACKGROUND
  Economically, Leuconostoc lactis is one of the most important species in the genus Leuconostoc. It plays an important role in the food industry including the production of dextrans and bacteriocins. Currently, traditional molecular typing approaches for characterisation of this species at the isolate level are either unavailable or are not sufficiently reliable for practical use. Multilocus sequence typing (MLST) is a robust and reliable method for characterising bacterial and fungal species at the molecular level. In this study, a novel MLST protocol was developed for 50 L. lactis isolates from Mongolia and China.
  
  
  RESULTS
  Sequences from eight targeted genes (groEL, carB, recA, pheS, murC, pyrG, rpoB and uvrC) were obtained. Sequence analysis indicated 20 different sequence types (STs), with 13 of them being represented by a single isolate. Phylogenetic analysis based on the sequences of eight MLST loci indicated that the isolates belonged to two major groups, A (34 isolates) and B (16 isolates). Linkage disequilibrium analyses indicated that recombination occurred at a low frequency in L. lactis, indicating a clonal population structure. Split-decomposition analysis indicated that intraspecies recombination played a role in generating genotypic diversity amongst isolates.
  
  
  CONCLUSIONS
  Our results indicated that MLST is a valuable tool for typing L. lactis isolates that can be used for further monitoring of evolutionary changes and population genetics.
authors.forename: Tong
authors.initials: T
authors.lastname: Dan
authors.forename: Wenjun
authors.initials: W
authors.lastname: Liu
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Sun
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lv
authors.forename: Haiyan
authors.initials: H
authors.lastname: Xu
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Song
authors.affiliation: Key Laboratory of Dairy Biotechnology and Engineering, Education Ministry of P, R, China, Department of Food Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, P, R, China. hepingdd@vip.sina.com.
authors.forename: Heping
authors.initials: H
authors.lastname: Zhang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D002681:China; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003611:Dairy Products / Q000382:microbiology*; D007934:Leuconostoc / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D008986:Mongolia; D058885:Multilocus Sequence Typing / Q000379:methods*; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial