Phenotypic characteristics and pathogenic ability across distinct morphotypes of Burkholderia pseudomallei DT.

Burkholderia pseudomallei DT is unusual as it exhibits six distinct colony morphotypes. Types III and V show stronger motility, whereas type VI exhibits the highest levels of bacterial association with peritoneal exudate cells. Although the bacterial loads in the organs are not significantly different for infections by the six distinct morphotypes, higher mortality (100% and 89%, respectively) and larger areas of abnormal liver debris (20.6% and 22.4%, respectively) are found with types I- and III-infected mice compared to the others. These morphotypes sometimes undergo switching to a mucoid type in the body of mice, but the reverse has never been observed.