Morphological Alteration and Survival of Burkholderia pseudomallei in Soil Microcosms.
The resilience of Burkholderia pseudomallei, the causative agent of melioidosis, was evaluated in control soil microcosms and in soil microcosms containing NaCl or FeSO4 at 30°C. Iron (Fe(II)) promoted the growth of B. pseudomallei during the 30-day observation, contrary to the presence of 1.5% and 3% NaCl. Scanning electron micrographs of B. pseudomallei in soil revealed their morphological alteration from rod to coccoid and the formation of microcolonies. The smallest B. pseudomallei cells were found in soil with 100 μM FeSO4 compared with in the control soil or soil with 0.6% NaCl (P < 0.05). The colony count on Ashdown's agar and bacterial viability assay using the LIVE/DEAD(®) BacLight(™) stain combined with flow cytometry showed that B. pseudomallei remained culturable and viable in the control soil microcosms for at least 120 days. In contrast, soil with 1.5% NaCl affected their culturability at day 90 and their viability at day 120. Our results suggested that a low salinity and iron may influence the survival of B. pseudomallei and its ability to change from a rod-like to coccoid form. The morphological changes of B. pseudomallei cells may be advantageous for their persistence in the environment and may increase the risk of their transmission to humans.
Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Environmental Science, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand; Biofilm Research Group, Department of Oral Diagnosis, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand; Melioidosis Research Center, Khon Kaen University, Khon Kaen, Thailand.
Watcharaporn
W
Kamjumphol
Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Environmental Science, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand; Biofilm Research Group, Department of Oral Diagnosis, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand; Melioidosis Research Center, Khon Kaen University, Khon Kaen, Thailand.
Pisit
P
Chareonsudjai
Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Environmental Science, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand; Biofilm Research Group, Department of Oral Diagnosis, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand; Melioidosis Research Center, Khon Kaen University, Khon Kaen, Thailand.
Suwimol
S
Taweechaisupapong
Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Environmental Science, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand; Biofilm Research Group, Department of Oral Diagnosis, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand; Melioidosis Research Center, Khon Kaen University, Khon Kaen, Thailand sorujsr@kku.ac.th.
Sorujsiri
S
Chareonsudjai
D016957:Burkholderia pseudomallei / Q000254:growth & development* / Q000648:ultrastructure; D004777:Environment; D005290:Ferric Compounds / Q000032:analysis; D006801:Humans; D008554:Melioidosis / Q000382:microbiology*; D050296:Microbial Viability; D008855:Microscopy, Electron, Scanning; D054712:Salinity; D012965:Sodium Chloride / Q000032:analysis; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
D005290:Ferric Compounds; D012987:Soil; C024823:ferric sulfate; D012965:Sodium Chloride