title: Competition between Burkholderia pseudomallei and B. thailandensis.
abstract: BACKGROUND
  Burkholderia pseudomallei is a Gram-negative bacterium that causes melioidosis, an often fatal disease in tropical countries. Burkholderia thailandensis is a non-virulent but closely related species. Both species are soil saprophytes but are almost never isolated together.
  
  
  RESULTS
  We identified two mechanisms by which B. pseudomallei affects the growth of B. thailandensis. First, we found that six different isolates of B. pseudomallei inhibited the growth of B. thailandensis on LB agar plates. Second, our results indicated that 55% of isolated strains of B. pseudomallei produced a secreted compound that inhibited the motility but not the viability of B. thailandensis. Analysis showed that the active compound was a pH-sensitive and heat-labile compound, likely a protein, which may affect flagella processing or facilitate their degradation. Analysis of bacterial sequence types (STs) demonstrated an association between this and motility inhibition. The active compound was produced from B. pseudomallei during the stationary growth phase.
  
  
  CONCLUSIONS
  Taken together, our results indicate that B. pseudomallei inhibits both the growth and motility of its close relative B. thailandensis. The latter phenomenon appears to occur via a previously unreported mechanism involving flagellar processing or degradation.
authors: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand. mulost@hotmail.com.
authors: Wikanda
authors: W
authors: Ngamdee
authors: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand. sarunporn.tan@mahidol.ac.th.|Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. sarunporn.tan@mahidol.ac.th.
authors: Sarunporn
authors: S
authors: Tandhavanant
authors: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. shaaed@gmail.com.
authors: Chanthiwa
authors: C
authors: Wikraiphat
authors: Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. onrapak.rea@mahidol.ac.th.
authors: Onrapak
authors: O
authors: Reamtong
authors: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. lek@tropmedres.ac.
authors: Vanaporn
authors: V
authors: Wuthiekanun
authors: Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. jeanne@tropmedres.ac.
authors: Jeanne
authors: J
authors: Salje
authors: Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, USA. david.low@lifesci.ucsb.edu.|Biomolecular Science and Engineering Program, University of California, Santa Barbara, CA, USA. david.low@lifesci.ucsb.edu.
authors: David A
authors: DA
authors: Low
authors: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand. sjp97@medschl.cam.ac.uk.|Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. sjp97@medschl.cam.ac.uk.|Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. sjp97@medschl.cam.ac.uk.
authors: Sharon J
authors: SJ
authors: Peacock
authors: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand. narisara@tropmedres.ac.|Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. narisara@tropmedres.ac.
authors: Narisara
authors: N
authors: Chantratita
mesh_terms: D000362:Agar; D000898:Antibiosis; D001426:Bacterial Proteins / Q000737:chemistry / Q000494:pharmacology*; D001685:Biological Factors / Q000737:chemistry / Q000494:pharmacology*; D019117:Burkholderia / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D016957:Burkholderia pseudomallei / Q000737:chemistry / Q000472:pathogenicity* / Q000502:physiology; D003470:Culture Media / Q000737:chemistry; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000494:pharmacology; D005407:Flagella / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D009068:Movement / Q000187:drug effects; D055550:Protein Stability; D059748:Proteolysis; D012988:Soil Microbiology; D013785:Thailand
chemical_list: D001426:Bacterial Proteins; D001685:Biological Factors; D003470:Culture Media; D017077:Culture Media, Conditioned; D000362:Agar