Myanmar Burkholderia pseudomallei strains are genetically diverse and originate from Asia with phylogenetic evidence of reintroductions from neighbouring countries

Melioidosis was first identified in Myanmar in 1911 but for the last century it has remained largely unreported there. Burkholderia pseudomallei was first isolated from the environment of Myanmar in 2016, confirming continuing endemicity. Recent genomic studies showed that B. pseudomallei originated in Australia and spread to Asia, with phylogenetic evidence of repeated reintroduction of B. pseudomallei across countries bordered by the Mekong River and the Malay Peninsula. We present the first whole-genome sequences of B. pseudomallei isolates from Myanmar: nine clinical and seven environmental isolates. We used large-scale comparative genomics to assess the genetic diversity, phylogeography and potential origins of B. pseudomallei in Myanmar. Global phylogenetics demonstrated that Myanmar isolates group in two distantly related clades that reside in a more ancestral Asian clade with high amounts of genetic diversity. The diversity of B. pseudomallei from Myanmar and divergence within our global phylogeny suggest that the original introduction of B. pseudomallei to Myanmar was not a recent event. Our study provides new insights into global patterns of B. pseudomallei dissemination, most notably the dynamic nature of movement of B. pseudomallei within densely populated Southeast Asia. The role of anthropogenic influences in both ancient and more recent dissemination of B. pseudomallei to Myanmar and elsewhere in Southeast Asia and globally requires further study

Enhanced melioidosis surveillance in patients attending four tertiary hospitals in Yangon, Myanmar

To investigate the current epidemiology of melioidosis in Yangon, Myanmar, between June 2017 and May 2019 we conducted enhanced surveillance for melioidosis in four tertiary hospitals in Yangon, where the disease was first discovered in 1911. Oxidase-positive Gram-negative rods were obtained from the microbiology laboratories and further analysed at the Department of Medical Research. Analysis included culture on Ashdown agar, the three disc sensitivity test (gentamicin, colistin and co-amoxiclav), latex agglutination, API 20 NE, antibiotic susceptibility testing, and a subset underwent molecular confirmation with a Burkholderia pseudomallei specific assay. Twenty one of 364 isolates (5.7%) were confirmed as B. pseudomallei and were mostly susceptible to the antibiotics used in standard therapy for melioidosis. Ten patients were from Yangon Region, nine were from Ayeyarwaddy region, and one each was from Kayin and Rakhine States. A history of soil contact was given by seven patients, five had diabetes mellitus and one had renal insufficiency. The patients presented with septicaemia (12 cases), pneumonia (three cases), urinary tract infection (two cases) and wound infection (four cases). Eighteen patients survived to hospital discharge. This study highlights the likelihood that melioidosis may be far more common, but underdiagnosed, in more rural parts of Myanmar as in other countries in SE Asia