Distribution of Melioidosis Cases and Viable Burkholderia pseudomallei in Soil: Evidence for Emerging Melioidosis in Taiwan

Abstract

A survey for the prevalence if Burkholderia pseudomallei in soil in Taiwan found that its incidence is comparable to that in other regions of the world where melioidosis is endemic. The presence of identical genetic patterns among the clinical and environmental isolates evaluated suggested a link between the pathogens present in contaminated soil and the emergence of indigenous melioidosis.

Alteration of the Phenotypic and Pathogenic Patterns of Burkholderia pseudomallei that Persist in a Soil Environment

“…Burkholderia pseudomallei vgh19 and B. pseudomallei CD were obtained from melioidosis patients or from soil environments. 19 From information on both strains, refer to the MLST (multilocus sequence typing) database (http://bpseudomallei.mlst.net/). 20 Mouse-derived B. pseudomallei strains NK19_mouse and NKcd_mouse were generated from the parent strains vgh19 and CD, respectively, by repeated intravenous injection into BALB/c mice.…”

Randomized Soil Survey of the Distribution of Burkholderia pseudomallei in Rice Fields in Laos

“…Melioidosis is an infectious disease caused by Burkholderia pseudomallei, a Gram-negative saprophytic soil bacterium (2,3,4,25,26,30). The majority of patients are reported in southeast Asia and northern Australia (3,4,25,26).…”

PCR-based Methodologies Used to Detect and Differentiate theBurkholderia pseudomalleicomplex:B. pseudomallei,B. mallei, andB. thailandensis

“…Chen et al recommends the fliC method with the possible addition of another PCR method (Dharakul et al, 1999) for detection of B. pseudomallei in soil samples. In fact, two epidemiological studies used Wajanarogana et al's and Dharakul et al's assays and reported that PCR was usually inferior to serology, but superior to culture in detecting B. pseudomallei in soil samples (Su et al, 2007;Chen et al, 2010). Chen et al's epidemiological study revealed 53 soil samples that were confirmed positive by Wajanarogana et al's and Dharakul et al's tests, but were negative by culture, indicating PCR sensitivity beyond culture (Chen et al, 2010 .…”

“…In fact, two epidemiological studies used Wajanarogana et al's and Dharakul et al's assays and reported that PCR was usually inferior to serology, but superior to culture in detecting B. pseudomallei in soil samples (Su et al, 2007;Chen et al, 2010). Chen et al's epidemiological study revealed 53 soil samples that were confirmed positive by Wajanarogana et al's and Dharakul et al's tests, but were negative by culture, indicating PCR sensitivity beyond culture (Chen et al, 2010 . Overall, 122018 produced a sensitivity of 100% and a specificity of 98.4%, due to six false positives detected by the B. pseudomallei specific probe.…”

“…Melioidosis had a 39% mortality rate in Singapore in 1996 , a 19% mortality rate in Australia in 2000 (Currie et al, 2000), a 50% mortality rate in northern Thailand in 2003 (White, 2003), and by 2006, mortality rates were about 40% in northern Thailand (Limmathurotsakul et al, 2010). While melioidosis is beginning to be recognized as an infectious threat (hence a lower mortality rate in recent years), cases of melioidosis are still increasing in number in populated areas such as southern China, Taiwan, Hong Kong, southern India, and Brazil (John et al, 1996;Yang, 2000;Currie et al, 2008;Chen et al, 2010;Brilhante et al, 2012). Eighty percent of children in northern Thailand have developed antibodies against this microbe by the age of four (Kanaphun et al, 1993), however due to the intracellular nature of the infection, antibodies are ineffective.…”