title: [Molecular typing of Listeria monocytogenes isolated from foodstuff in Guangdong province by pulsed-field gel electrophoresis].
abstract: OBJECTIVE
  To establish molecular typing of Listeria monocytogenes isolates by pulsed-field gel electrophoresis (PFGE) for studying the epidemiologic characteristics of Listeria monocytogenes isolated from foodstuff in Guangdong province and to build up PFGE typing database of Listeria monocytogenes isolates for identifying the infectious resource of the outbreaks and other epidemiologic investigation.
  
  
  METHODS
  "Standardized Protocol for Molecular Subtyping of Listeria monocytogenes by PFGE" was followed. BioNumerics software was applied on image analysis, database establishment, comparative and corresponding analysis.
  
  
  RESULTS
  107 Listeria monocytogenes isolates were typed by PFGE, 41 PFGE types were observed among the isolates. The PFGE types were dispersive among these isolates. Listeria monocytogenes isolates were most frequently isolated in raw chicken while the most PFGE types were found in this type of food. The positive rate was relatively high in cold and iced foods. Only 1-2 DNA fragment difference occurred in 26 Listeria monocytogenes isolates by PFGE, so high degree of relatedness remained among these isolates. There were unique PFGE patterns in the regions of Shaoguan and Huizhou. From time to time, a number of isolates remained close relationship.
  
  
  CONCLUSIONS
  PFGE typing of the 107 Guangdong Listeria monocytogenes isolates demonstrated relative genetic diversity but a number of the isolates showed close relatedness.
authors.affiliation: Institute of Microbiology, Guangdong Province Center for Disease Control and Prevention, Guangzhou 510300, China.
authors.forename: Dong-mei
authors.initials: DM
authors.lastname: He
authors.forename: Feng
authors.initials: F
authors.lastname: Deng
authors.forename: Hong-min
authors.initials: HM
authors.lastname: Wang
authors.forename: Chang-wen
authors.initials: CW
authors.lastname: Ke
authors.forename: Ji-wen
authors.initials: JW
authors.lastname: Yan
authors.forename: Hai-ming
authors.initials: HM
authors.lastname: Zhu
authors.forename: Wei-dong
authors.initials: WD
authors.lastname: Lai
authors.forename: Man-dan
authors.initials: MD
authors.lastname: Song
authors.forename: Bing
authors.initials: B
authors.lastname: Yang
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Ma
authors.initials: M
authors.lastname: Cong
authors.forename: Bi-xia
authors.initials: BX
authors.lastname: Ke
authors.forename: Xiao-ling
authors.initials: XL
authors.lastname: Deng
authors.forename: Han-zhong
authors.initials: HZ
authors.lastname: Ni
mesh_terms: D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D005516:Food Microbiology; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D008089:Listeria monocytogenes / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D010802:Phylogeny