Laboratory investigation of ecological factors influencing the environmental presence of Burkholderia pseudomallei.

Factors like temperature, pH value, water content in soil, and ultraviolet rays that might have influence on the survival of environmental Burkholderia pseudomallei strains were evaluated. Data showed that the optimal temperature and pH value for B. pseudomallei were 24 C to 32 C and 5 to 8, respectively. Water content in soil of less than 10% brought about the death of the bacteria within 70 days, while water content of more than 40% maintained bacteria life for 726 days. The bacteria were easily killed by ultraviolet rays at 465 mu W/cm2 for 7.75 min while other permanent soil bacteria were killed at 1,860 mu W/cm2 for 31 min. From these results, it could be concluded that proper temperature, enough water in soil, and suitable soil pH might be the three major ecological conditions governing the environmental presence of B. pseudomallei.