title: Genetic diversity and antimicrobial resistance pattern of Salmonella enterica serovar Enteritidis clinical isolates in Thailand.
abstract: OBJECTIVE
  To trace the history of antimicrobial resistance in Salmonella enterica serovar Enteritidis (S. Enteritidis, SE) circulating in Thailand, we characterised clinical isolates obtained during 2004-2007.
  
  
  METHODS
  Antimicrobial resistance profiles, multi-locus variable number tandem repeat analysis (MLVA) types and 3 representative virulence determinants (spvA, sodCI and sopE) were established from SE isolates (n = 192) collected from stool and blood of patients throughout Thailand during the period 2004-2007.
  
  
  RESULTS
  Resistance was found in SE against 10 out of 11 antimicrobials studied. The highest resistance ratios were observed for nalidixic acid (83.2%), ciprofloxacin (51.1%) and ampicillin (50.5%), and 25.5% were multidrug resistant. Based on five polymorphic tandem repeat loci analysis, MLVA identified 20 distinct types with three closely related predominant types. A significant increase of AMP resistance from 2004 to 2006 was strongly correlated with that of a MLVA type, 5-5-11-7-3.
  
  
  CONCLUSIONS
  The usage of antimicrobials in human medicine or farm settings might act as selective pressures and cause the spread of resistant strains. Hence, a strict policy on antimicrobial usage needs to be implemented to achieve the control of resistant SE in Thailand.
authors: Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
authors: Fuangfa
authors: F
authors: Utrarachkij
authors: Division of Bioresources Hokkaido University, Research Center for Zoonosis Control, Sapporo, Japan; Hokkaido University, The Global Station for Zoonosis Control, Sapporo, Japan.
authors: Chie
authors: C
authors: Nakajima
authors: Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
authors: Kanokrat
authors: K
authors: Siripanichgon
authors: Division of Bioresources Hokkaido University, Research Center for Zoonosis Control, Sapporo, Japan.
authors: Kanjana
authors: K
authors: Changkaew
authors: Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
authors: Yuwanda
authors: Y
authors: Thongpanich
authors: National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi, Thailand.
authors: Srirat
authors: S
authors: Pornraungwong
authors: Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok, Thailand. Electronic address: orasa.sut@mahidol.ac.th.
authors: Orasa
authors: O
authors: Suthienkul
authors: Division of Bioresources Hokkaido University, Research Center for Zoonosis Control, Sapporo, Japan; Hokkaido University, The Global Station for Zoonosis Control, Sapporo, Japan. Electronic address: suzuki@czc.hokudai.ac.jp.
authors: Yasuhiko
authors: Y
authors: Suzuki
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial; D024881:Drug Resistance, Bacterial; D005798:Genes, Bacterial; D014644:Genetic Variation; D006801:Humans; D008826:Microbial Sensitivity Tests; D018598:Minisatellite Repeats; D012189:Retrospective Studies; D012480:Salmonella Infections / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013785:Thailand; D037521:Virulence Factors
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D037521:Virulence Factors
keywords: Antimicrobial resistance; MLVA typing; Salmonella Enteritidis