Burkholderia pseudomallei: Challenges for the Clinical Microbiology Laboratory

Abstract

bMelioidosis is a potentially fatal infection caused by the bacterium Burkholderia pseudomallei. Clinical diagnosis of melioidosis can be challenging since there is no pathognomonic clinical syndrome, and the organism is often misidentified by methods used routinely in clinical laboratories. Although the disease is more prevalent in Thailand and northern Australia, sporadic cases may be encountered in areas where it is not endemic, including the United States. Since the organism is considered a tier 1 select agent according to the Centers for Disease Control and Prevention and the U.S. Department of Agriculture Animal and Plant Health Inspection Service, clinical laboratories must be proficient at rapidly recognizing isolates suspicious for B. pseudomallei, be able to safely perform necessary rule-out tests, and to refer suspect isolates to Laboratory Response Network reference laboratories. In this minireview, we report a case of melioidosis encountered at our institution and discuss the laboratory challenges encountered when dealing with clinical isolates suspicious for B. pseudomallei or clinical specimens from suspected melioidosis cases. CASEA 67-year-old Filipino woman with a previous history of treated tuberculosis, hypertension, type 2 diabetes, coronary artery disease, and complete heart block requiring a pacemaker and drug-eluting stent that was placed 4 months earlier presented to an outside hospital with 2 weeks of progressive left lower quadrant abdominal pain, chills, and subjective fever. She was evaluated in different emergency departments for similar complaints on two occasions in the preceding week, but was discharged home. She was admitted to an outside hospital on this visit and computed tomography (CT) of the abdomen and pelvis with intravenous contrast revealed an 8 by 8 by 8 mm suprarenal saccular aneurysm arising from the posterior aortic wall with surrounding inflammation. Blood cultures drawn in the emergency department grew a Gram-negative rod, which was identified by the Vitek 2 (bioMérieux, Durham NC) as Burkholderia pseudomallei. This identification was confirmed several weeks later by the Centers for Disease Control and Prevention (CDC). Transthoracic echocardiography showed no vegetation. The patient was treated with meropenem 1 g intravenously (i.v.) every 8 hours (q8h). Follow-up CT scans performed 9 days after presentation showed that the mycotic aneurysm had enlarged to 13 by 24 by 20 mm and revealed a second aneurysm of the lateral wall of the aorta measuring 4 by 4 mm.The patient was transferred to our institution for surgical evaluation. On arrival, two sets of blood cultures (BD Bactec FX system; Becton, Dickinson and Company, NJ) were collected. Within 48 h of transfer, the patient underwent surgical excision of the mycotic aneurysm and reconstruction of her aorta using bioprosthetic homografts. During the procedure, the aneurysm was found to have ruptured, with the resulting pseudoaneurysm encased in inflammatory material and purulent fluid. Intraoperative samples from t...

The Brief Case: A Traveler’s Tale—Burkholderia pseudomallei Infection in a Cystic Fibrosis Patient

“…Melioidosis is caused by the Gram-negative bacterium Burkholderia pseudomallei, which is classically found in regions of endemicity of Southeast Asia and Northern Australia (4,5). Infection is acquired through direct inoculation, inhalation, or ingestion of contaminated soil or water with an incubation period of 1 to 21 days (4-10).…”

“…Infection is acquired through direct inoculation, inhalation, or ingestion of contaminated soil or water with an incubation period of 1 to 21 days (4-10). The typical presentation with melioidosis in adults is pneumonia, which ranges from mild disease to subacute pulmonary disease mimicking tuberculosis to fulminant septic shock (4)(5)(6)(7)(8)(9)(10). Extrapulmonary presentations such as cutaneous infections, septic arthritis, genitourinary infections, and encephalitis have been reported (4)(5)(6)(7)(8)(9)(10).…”

Isolasi Dan Identifikasi Bakteri Tanah Burkholderia Pseudomalllei Penyebab Melioidosis Di Kota Makassar

“…5 Burkholderia pseudomallei merupakan agen penyebab penyakit melioidosis dan telah banyak dilaporkan di beberapa negara seperti Amerika, Australia, dan beberapa negara di Asia Tenggara, namun jarang dilaporkan di Indonesia. 6,7 Sebuah studi pemodelan terbaru memperkirakan bahwa sebanyak 20.000 kasus melioidosis pada manusia per tahun di Indonesia, dengan sekitar 10.000 kematian potensial setiap tahunnya. Meski demikian, melioidosis di Indonesia masih belum diketahui.…”

Burkholderia pseudomallei clinical isolates are highly susceptible in vitro to cefiderocol, a novel siderophore cephalosporin

“…B. pseudomallei is endemic to tropical and sub-tropical regions, including south-east Asia and northern Australia and suspected for Africa and South America 15–17 . The bacteria is known to cause melioidosis, where pneumonia, sepsis, neurological disease and visceral abscesses are commonly described clinical presentations 15,18 . Treatment for B. pseudomallei infections require an “intensive” 2-8-week intravenous treatment with an antimicrobial such as a carbapenem or cephalosporin, then followed by and orally administered “eradication” treatment for 3-6 months with an antimicrobial such as trimethoprim-sulfamethoxazole 19 .…”