Woman's Wound Infection Caused By Burkholderia thailandensis

Jay E. Gee, PhD

A recent report has described a case of wound infection with the bacterium Burkholderia thailandensis in a woman in Arkansas.

Jay E. Gee, PhD, from the US Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, and colleagues published the report in the November 2018 issue of Emerging Infectious Diseases, the monthly peer-reviewed public health journal of the CDC.

Burkholderia thailandensis is closely related to the bacterium B pseudomallei, which causes melioidosis. Both organisms are commonly found in the environment, particularly in tropical and subtropical climates. Although usually considered nonpathogenic, rare cases of infection with B thailandensis have been reported in humans. These infections often result from injuries that expose a wound to soil.

In the United States, the first reported case occurred in Louisiana in 1997, in a 76-year-old man with a pleural wound; and the second occurred in Texas in 2003, in a previously healthy 2-year-old boy who aspirated water from a ditch after a car accident.

Dr. Gee and colleagues describe a recent case in a 29-year-old woman in Arkansas who suffered an open forearm fracture after crashing while driving an all-terrain vehicle. She underwent surgery and a metal plate was used to stabilize the fracture. The patient returned to the hospital 3 months later because of swelling of her forearm, and received antimicrobial treatment consisting of piperacillin/tazobactam, vancomycin, and cefazolin.

Doctors also collected tissue from deep in the forearm at the surgical site, and submitted this sample for microbial culture.

Because of the similarities between B thailandensis and B pseudomallei, they can be difficult to differentiate. Indeed, in this case, the laboratory initially reported growth of B pseudomallei and a diagnosis of melioidosis was made. However, the Arkansas Department of Health then ruled out the presence of B pseudomallei in the tissue specimen by using biochemical and PCR testing, and instead identified it as B thailandensis. They then forwarded the isolate to CDC for confirmation. The woman was discharged and treated with ceftazidime intravenously for 6 weeks, and was reported to be completely healed as of December 2017.

“B thailandensis can be misidentified as its close relative B. pseudomallei, a tier 1 select agent which causes the potentially fatal disease melioidosis,” Dr. Gee, told Contagion®.

“But, unlike B pseudomallei, our work suggests that B thailandensis may be endemic in the continental United States, so the ability to correctly and quickly identify and differentiate these bacteria is vital for appropriate patient treatment and public health responses," he emphasized.

The authors conclude that further study of B thailandensis is needed to improve understanding of its geographic range and ability to cause infections.