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.

Abstract 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.</jats:p

Genetic characterization of blaNDM-harboring plasmids in carbapenem-resistant Escherichia coli from Myanmar.

The bacterial enzyme New Delhi metallo-β-lactamase hydrolyzes almost all β-lactam antibiotics, including carbapenems, which are drugs of last resort for severe bacterial infections. The spread of carbapenem-resistant Enterobacteriaceae that carry the New Delhi metallo-β-lactamase gene, blaNDM, poses a serious threat to public health. In this study, we genetically characterized eight carbapenem-resistant Escherichia coli isolates from a tertiary care hospital in Yangon, Myanmar. The eight isolates belonged to five multilocus-sequence types and harbored multiple antimicrobial-resistance genes, resulting in resistance against nearly all of the antimicrobial agents tested, except colistin and fosfomycin. Nine plasmids harboring blaNDM genes were identified from these isolates. Multiple blaNDM genes were found in the distinct Inc-replicon types of the following plasmids: an IncA/C2 plasmid harboring blaNDM-1 (n = 1), IncX3 plasmids harboring blaNDM-4 (n = 2) or blaNDM-7 (n = 1), IncFII plasmids harboring blaNDM-4 (n = 1) or blaNDM-5 (n = 3), and a multireplicon F plasmid harboring blaNDM-5 (n = 1). Comparative analysis highlighted the diversity of the blaNDM-harboring plasmids and their distinct characteristics, which depended on plasmid replicon types. The results indicate circulation of phylogenetically distinct strains of carbapenem-resistant E. coli with various plasmids harboring blaNDM genes in the hospital

Melioidosis in Myanmar

Sporadic cases of melioidosis have been diagnosed in Myanmar since the disease was first described in Yangon in 1911. Published and unpublished cases are summarized here, along with results from environmental and serosurveys. A total of 298 cases have been reported from seven states or regions between 1911 and 2018, with the majority of these occurring before 1949. Findings from soil surveys confirm the presence of Burkholderia pseudomallei in the environment in all three regions examined. The true epidemiology of the disease in Myanmar is unknown. Important factors contributing to the current gaps in knowledge are lack of awareness among clinicians and insufficient laboratory diagnostic capacity in many parts of the country. This is likely to have led to substantial under-reporting

Circular map of plasmid pM105_mF.

<p>The outermost circle indicates size in bp. The next circle indicates composite transposons (dark gray) and regions homologous to the <i>bla</i>_NDM-5 region in pM214_FII (yellow) and pV228-a (dark green). The third and fourth circles show coding sequences transcribed clockwise and anti-clockwise, respectively. Genes are indicated in colors as defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184720#pone.0184720.g002" target="_blank">Fig 2</a>, except that genes involved in plasmid replication and maintenance are illustrated in green. R-M, R-S, and R-R denote restriction-modification genes (M, methylase; S, specificity; and R, restriction). The innermost circle shows GC content.</p

IncFII plasmids harboring <i>bla</i>_NDM.

<p>(A) Comparison of IncFII plasmids harboring <i>bla</i>_NDM in Myanmar isolates. Homologous regions are shaded gray, with the percent identity shaded according to the color bar. The arrowhead indicates a deletion in pM107_FII that encompasses several genes involved in conjugal transfer. The arrow indicates a deletion of a gene cluster carrying <i>bla</i>_NDM-5 in pM105_FII. Genes are indicated in colors as defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184720#pone.0184720.g002" target="_blank">Fig 2</a>, except that genes involved in conjugal transfer and toxin-antitoxin modules are illustrated in green and black, respectively. (B) Schematic representation of the genetic context of <i>bla</i>_NDM. Identical regions are shaded gray, whereas arrows denote gene-cluster insertions. (C) Maximum-likelihood tree of IncFII plasmids harboring <i>bla</i>_NDM. Encoded NDM variants are shown in parentheses along with geographical origin. IncFII plasmids lacking <i>bla</i>_NDM and found in Myanmar isolates were also included and are indicated in italics. Bootstrap support values based on 1000 replications are indicated at the branching points. All the plasmids, except for pCC1409-1 and pCC1410-1, which were identified in <i>K</i>. <i>pneumoniae</i> isolates, were isolated from <i>E</i>. <i>coli</i>.</p

IncX3 plasmids harboring <i>bla</i>_NDM.

<p>(A) Schematic representation of the <i>bla</i>_NDM-4 plasmid pM216_X3 and comparison of the genetic context of <i>bla</i>_NDM in IncX3 plasmids. Genes are indicated in colors as defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184720#pone.0184720.g002" target="_blank">Fig 2</a>, except that genes involved in conjugal transfer are depicted in green. A 92-bp deletion that is found in pM110_X3, pM213_X3, pM216_X3, pKpN01-NDM7, and pOM26-1 is indicated by the arrow. (B) Evolutionary relationship of fully sequenced IncX3 plasmids harboring <i>bla</i>_NDM as inferred from genetic variances. Encoded NDM variants are shown in parentheses along with geographical origin. The plasmids identified in this study are boxed. pJEG027, pNDM-MGR194, and pKpN01-NDM7 were isolated from <i>K</i>. <i>pneumoniae</i> isolates and are shaded gray. pOM26-1 was isolated from an <i>E</i>. <i>coli</i> isolate. SNS, single nucleotide substitution.</p

IncA/C₂ plasmids harboring <i>bla</i>_NDM-1.

<p>(A) Comparison of IncA/C₂ plasmids isolated in this study with similar and/or putative backbone plasmids pNDM-1_Dok01 and pR148. Homologous regions are shaded dark gray. Genes are indicated in colors as follows: <i>bla</i>_NDM-1, red; other β-lactamases, purple; other antimicrobial-resistance genes, orange; IS<i>26</i>, blue; other mobile genetic elements, cyan; other accessory genes, light gray. The origins of the indicated plasmids are shown in parentheses. pM214_ A/C₂ and pNDM-1_Dok01 harbor the class C β-lactamase gene, <i>bla</i>_CMY-4. (B) Schematic representation of the genetic context of <i>bla</i>_NDM-1 in pM214_ A/C₂ and in other plasmids.</p

MICs of antimicrobial agents for <i>E</i>. <i>coli</i> clinical isolates from Myanmar.

<p>MICs of antimicrobial agents for <i>E</i>. <i>coli</i> clinical isolates from Myanmar.</p

Phylogeny of carbapenem-resistant <i>E</i>. <i>coli</i> isolated in Myanmar and features of their <i>bla</i>_NDM-harboring plasmids.

<p>(A) Phylogenetic tree of carbapenem-resistant <i>E</i>. <i>coli</i> isolates based on WGS. Reference genomes and several other available genomes were included for comparison. Phylogroups of the reference strains are indicated in boxes. (B) Multilocus-sequence types, NDM types, plasmid-replicon types, and antimicrobial-resistance profiles determined by database search. In strain M214, NDM types are indicated by numbers on black-shaded boxes.</p