title: Direct detection of Burkholderia pseudomallei and biological factors in soil.
abstract: BACKGROUND
  Burkholderia pseudomallei, a Gram-negative saprophytic bacillus, is a severe infectious agent that causes melioidosis and soil is the most important reservoir.
  
  
  METHODS
  One hundred and forty soil samples were tested for pH, moisture content and total C and N measurements and used for DNA extraction and culture for B. pseudomallei. The quantitative real-time PCR (qPCR) targeting wcbG, a putative capsular polysaccharide biosynthesis protein gene of B. pseudomallei, was developed to detect the bacterium, and random amplified polymorphic DNA (RAPD) was used to detect the microbial diversity in soil.
  
  
  RESULTS
  The acidic pH was correlated with the presence of the bacterium. Forty-four soil sites (44/140, 31.4%) were positive for B. pseudomallei by qPCR, of which 21 were positive by culture. The limit of detection is 32 fg of DNA (about 4 genomes). The RAPD method could classify the soil samples into low diversity (LD) and high diversity (HD) sites. The trend of LD was found with B. pseudomallei positive soil sites.
  
  
  CONCLUSIONS
  The acidity of the soil or metabolites from organisms in the sites may contribute to the presence of the bacterium. Further investigation of microbes by a more robust method should elucidate biological factors that promote the presence of B. pseudomallei and may be used for controlling the bacterium in the environment.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kean University, 123 Mitraparp Rd, Khon Kaen 40002, Thailand Melioidosis Research Center, Faculty of Medicine, Khon Kean University, Khon Kaen, Thailand rasana@kku.ac.th.
authors.forename: Rasana W
authors.initials: RW
authors.lastname: Sermswan
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kean University, 123 Mitraparp Rd, Khon Kaen 40002, Thailand Melioidosis Research Center, Faculty of Medicine, Khon Kean University, Khon Kaen, Thailand.
authors.forename: Phairat
authors.initials: P
authors.lastname: Royros
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kean University, 123 Mitraparp Rd, Khon Kaen 40002, Thailand Melioidosis Research Center, Faculty of Medicine, Khon Kean University, Khon Kaen, Thailand.
authors.forename: Nittaya
authors.initials: N
authors.lastname: Khakhum
authors.affiliation: Melioidosis Research Center, Faculty of Medicine, Khon Kean University, Khon Kaen, Thailand Department of Microbiology, Faculty of Medicine, Khon Kean University, Khon Kaen, Thailand.
authors.forename: Surasakdi
authors.initials: S
authors.lastname: Wongratanacheewin
authors.affiliation: Department of Infectious Diseases and Pathology, University of Florida, Gainesville, Florida, USA.
authors.forename: Apichai
authors.initials: A
authors.lastname: Tuanyok
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D016957:Burkholderia pseudomallei / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000235:genetics; D057230:Limit of Detection; D011135:Polysaccharides, Bacterial / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial
keywords: Burkholderia pseudomallei; Diversity; Quantitative real-time PCR; Random amplified polymorphic DNA; Soil