Development and validation of TaqMan real-time PCR for the detection of Burkholderia pseudomallei isolates from Malaysia

Rapid detection of Burkholderia pseudomallei, the etiologic agent of melioidosis, allows for timely initiation of appropriate treatment and better clinical outcomes. In the current gold standard, the culture method is time consuming and suffers from low sensitivity. Meanwhile, previously reported molecular assays are fast and sensitive, but their performance on isolates from Malaysia, an endemic region of melioidosis is under reported. This study designed oligonucleotides targeting orf2 of Type III secretion system (TTSS) genes cluster for the detection of Malaysian B. pseudomallei isolates and evaluated the assay on 95 local B. pseudomallei strains, 58 other microorganisms and 71 clinical specimens from patients. The developed assay exclusively detected all tested B. pseudomallei isolates with a detection limit of 20 fg per reaction (equivalent to ~2.5 copies). Subsequent testing on clinical samples showed that the assay detected all confirmed specimens with the growth of B. pseudomallei (n = 10/10). None of the negative specimens had a detectable signal of our TTSS-orf2 assay (n = 0/61). In conclusion, the present study provides crucial preliminary data for a subsequent study and should be considered as a potential alternative to current time-consuming culture method for the detection of B. pseudomallei.

Familial antithrombin III deficiency in a Malay patient with massive thrombosis

Patients with low antithrombin III (AT III) has increased risk for arteriovenous thromboembolic (TE) disease. We report a 28-year-old Malay lady who presented with spontaneous right calf pain and swelling of one week duration. She was on oral contraceptive pills and had a history of travelling for a long distance prior to the presentation. Her brother who was diagnosed with AT III deficiency had arterial thrombosis at a young age. She was diagnosed as having right popliteal vein thrombosis by ultrasound and treated with subcutaneous fondaparinux. While on treatment, she developed massive bilateral pulmonary embolism (PE). Thrombophilia study showed reduced AT III activity (38μl/dl) and normal results for protein C, protein S, activated protein C resistance and lupus anticoagulant assays. This patient has heterozygous AT III deficiency added with significant acquired factors responsible for the TE events. Those with AT III deficiency may have resistance to heparin therapy and require higher doses of heparin.