Multilocus sequence types of clinical Burkholderia pseudomallei isolates from peninsular Malaysia and their associations with disease outcomes.

BACKGROUND: Previous studies on the Burkholderia pseudomallei genetic diversity among clinical isolates from melioidosis-endemic areas have identified genetic factors contributing to differential virulence. Although it has been ruled out in Australian and Thai B. pseudomallei populations, it remains unclear whether B. pseudomallei sequence types (STs) correlate with disease in Malaysian patients with melioidosis. METHODS: In this study, multi-locus sequence typing (MLST) was performed on clinical B. pseudomallei isolates collected from Kelantan state of Malaysia, patients' clinical data were reviewed and then genotype-risk correlations were investigated. RESULTS: Genotyping of 83 B. pseudomallei isolates revealed 32 different STs, of which 13(40%) were novel. The frequencies of the STs among the 83 isolates ranged from 1 to 12 observations, and ST54, ST371 and ST289 were predominant. All non-novel STs reported in this study have also been identified in other Asian countries. Based on the MLST data analysis, the phylogenetic tree showed clustering of the STs with each other, as well as with the STs from Southeast Asia and China. No evidence for associations between any of B. pseudomallei STs and clinical melioidosis presentation was detected. In addition, the bacterial genotype clusters in relation with each clinical outcome were statistically insignificant, and no risk estimate was reported. This study has expanded the data for B. pseudomallei on MLST database map and provided insights into the molecular epidemiology of melioidosis in Peninsular Malaysia. CONCLUSION: This study concurs with previous reports concluding that infecting strain type plays no role in determining disease presentation.

The epidemiology and clinical spectrum of melioidosis in a teaching hospital in a North-Eastern state of Malaysia: a fifteen-year review.

BACKGROUND: Over the last two decades, many epidemiological studies were performed to describe risks and clinical presentations of melioidosis in endemic countries. METHODS: We performed a retrospective analysis of 158 confirmed cases of melioidosis collected from medical records from 2001 to 2015 in Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia, in order to update the current status of melioidosis clinical epidemiology in this putatively high risk region of the country. RESULTS: Principal presentations in patients were lung infection in 65 (41.1 %), skin infection in 44 (27.8 %), septic arthritis/osteomyelitis in 20 (12.7 %) and liver infection in 19 (12.0 %). Bacteremic melioidosis was seen in most of patients (n = 121, 76.6 %). Focal melioidosis was seen in 124 (78.5 %) of patients and multi-focal melioidosis was reported in 45 (28.5 %) cases. Melioidosis with no evident focus was in 34 (21.5 %) patients. Fifty-four (34.2 %) patients developed septic shock. Internal organ abscesses and secondary foci in lungs and/or soft tissue were common. A total of 67 (41 %) cases presented during the monsoonal wet season. Death due to melioidosis was reported in 52 (32.9 %) patients, while relapses were occurred in 11 (7.0 %). Twelve fatal melioidosis cases seen in this study were directly attributed to the absence of prompt acute-phase treatment. Predisposing risk factors were reported in most of patients (n = 133, 84.2 %) and included diabetes (74.7 %), immune disturbances (9.5 %), cancer (4.4 %) and chronic kidney disease (11.4 %). On multivariate analysis, the only independent predictors of mortality were the presence of at least one co-morbid factor (OR 3.0; 95 % CI 1.1-8.4), the happening of septic shock (OR 16.5; 95 % CI 6.1-44.9) and age > 40 years (OR 6.47; 95 % CI 1.7-23.8). CONCLUSIONS: Melioidosis should be recognized as an opportunistic nonfatal infection for healthy person. Prompt early diagnosis and appropriate antibiotics administration and critical care help in improved management and minimizing risks for death.

Osteoarticular and soft-tissue melioidosis in Malaysia: clinical characteristics and molecular typing of the causative agent.

INTRODUCTION: Melioidosis involving bone, joints, and soft tissue is rare and reported usually following dissemination of disease from infection elsewhere in the body; to a lesser degree, it can also be reported as the primary manifestation of melioidosis. METHODOLOGY: The orthopedic registry at Hospital University Sains Malaysia from 2008 until 2014 was retrospectively reviewed and was followed by molecular typing of Burkholderia pseudomallei. RESULTS: Out of 20 cases identified, 19 patients were confirmed to have osteoarticular and/or soft-tissue melioidosis. The majority of the patients were males (84%), and 16 patients had underlying diabetes mellitus with no significant estimated risk with the disease outcomes. Bacterial genotype was not associated with the disease as a risk. Death was a significant outcome in patients with bacteremic infections (p = 0.044). CONCLUSION: Patients with lung or skin melioidosis require careful treatment follow-up to minimize the chance for secondary osteoarticular infection. Human risk factors remain the leading predisposing factors for melioidosis. Early laboratory and clinical diagnosis and acute-phase treatment can decrease morbidity and mortality.