Institute for Combinatorial Advance Research and Education (KDU-CARE), General Sir John Kotelawala Defence University, Ratmalana, Sri Lanka.
Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
PLoS Negl Trop Dis. 2021 Dec 1;15(12):e0009917. doi: 10.1371/journal.pntd.0009917. eCollection 2021 Dec.
Melioidosis is a potentially fatal infectious disease caused by Burkholderia pseudomallei and the disease is endemic in Southeast Asia and Northern Australia. It has been confirmed as endemic in Sri Lanka. Genomic epidemiology of B. pseudomallei in Sri Lanka is largely unexplored. This study aims to determine the biogeography and genetic diversity of clinical isolates of B. pseudomallei and the phylogenetic and evolutionary relationship of Sri Lankan sequence types (STs) to those found in other endemic regions of Southeast Asia and Oceania.
The distribution of variably present genetic markers [Burkholderia intracellular motility A (bimA) gene variants bimABP/bimABM, filamentous hemagglutinin 3 (fhaB3), Yersinia-like fimbrial (YLF) and B. thailandensis-like flagellum and chemotaxis (BTFC) gene clusters and lipopolysaccharide O-antigen type A (LPS type A)] was examined among 310 strains. Multilocus sequence typing (MLST) was done for 84 clinical isolates. The phylogenetic and evolutionary relationship of Sri Lankan STs within Sri Lanka and in relation to those found in other endemic regions of Southeast Asia and Oceania were studied using e BURST, PHYLOViZ and minimum evolutionary analysis.
The Sri Lankan B. pseudomallei population contained a large proportion of the rare BTFC clade (14.5%) and bimABM allele variant (18.5%) with differential geographic distribution. Genotypes fhaB3 and LPSA were found in 80% and 86% respectively. This study reported 43 STs (including 22 novel). e-BURST analysis which include all Sri Lankan STs (71) resulted in four groups, with a large clonal group (group 1) having 46 STs, and 17 singletons. ST1137 was the commonest ST. Several STs were shared with India, Bangladesh and Cambodia.
This study demonstrates the usefulness of high-resolution molecular typing to locate isolates within the broad geographical boundaries of B. pseudomallei at a global level and reveals that Sri Lankan isolates are intermediate between Southeast Asia and Oceania.
类鼻疽是一种由伯克霍尔德氏菌引起的潜在致命传染病，该病在东南亚和澳大利亚北部流行。现已证实斯里兰卡也存在该病流行。对斯里兰卡伯克霍尔德氏菌的基因组流行病学研究仍在探索中。本研究旨在确定临床分离株的生物地理学和遗传多样性，以及斯里兰卡序列型（ST）与东南亚和大洋洲其他流行地区发现的序列型的系统发育和进化关系。
检测了 310 株菌中可变存在的遗传标记[伯克霍尔德氏菌内动力 A（bimA）基因变体 bimABP/bimABM、丝状血凝素 3（fhaB3）、类耶尔森氏菌菌毛（YLF）和 B. 泰国菌样鞭毛和趋化性（BTFC）基因簇和脂多糖 O-抗原型 A（LPS 型 A）]的分布。对 84 株临床分离株进行多位点序列分型（MLST）。使用 eBURST、PHYLOViZ 和最小进化分析研究了斯里兰卡 ST 在内的斯里兰卡和与东南亚和大洋洲其他流行地区发现的 ST 的系统发育和进化关系。
斯里兰卡伯氏菌种群包含很大比例的罕见 BTFC 分支（14.5%）和 bimABM 等位基因变体（18.5%），具有不同的地理分布。fhaB3 和 LPSA 基因型分别发现于 80%和 86%的菌株中。本研究报告了 43 个 ST（包括 22 个新 ST）。包括所有斯里兰卡 ST（71 个）的 eBURST 分析产生了 4 个组，其中一个大的克隆群（群 1）有 46 个 ST，17 个单型。ST1137 是最常见的 ST。一些 ST 与印度、孟加拉国和柬埔寨共有。
本研究证明了高分辨率分子分型在全球范围内定位伯氏菌广泛地理范围内的分离株的有用性，并表明斯里兰卡分离株介于东南亚和大洋洲之间。
