Baker Anthony L, Warner Jeffrey M
Environmental and Public Health Microbiology Research Group, School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland, Australia.
Tasmanian Institute of Agriculture (TIA), University of Tasmania, Hobart, Tasmania, Australia.
Folia Microbiol (Praha). 2016 Jul;61(4):301-5. doi: 10.1007/s12223-015-0438-3. Epub 2015 Nov 30.
Burkholderia pseudomallei is the environmental bacterium that causes the serious disease melioidosis. Recently, a high prevalence of viable B. pseudomallei was reported from natural groundwater seeps around Castle Hill, a clinical focus of melioidosis in Townsville, Australia. This study sought to expand previous findings to determine the extent of B. pseudomallei in more diverse natural groundwater seeps in northern Queensland to ascertain if the presence of the organism in groundwater on Castle Hill was an isolated occurrence. Analysis of water samples (n = 26) obtained from natural groundwater seeps following an intensive rainfall event in the Townsville region determined the presence of B. pseudomallei DNA in duplicates of 18 samples (69.2 % [95 % CI, 51.5 to 87.0]). From 26 water samples, a single isolate of B. pseudomallei was recovered despite plating of both pre-enriched samples and original water samples onto selective media, indicating that the sensitivity of these molecular techniques far exceeds culture-based methods. Furthermore, the identification of new environments endemic for melioidosis may be more effectively determined by analysing surface groundwater seeps than by the analysis of random soil samples. This study suggests that a higher incidence of melioidosis following monsoonal rains may be partially the result of exposure to groundwater sources carrying B. pseudomallei, and that modifications to public health messages in endemic regions may be warranted. Moreover, these findings have implications for predictive models of melioidosis, effective models requiring consideration of topographical and surface hydrological data.
类鼻疽伯克霍尔德菌是一种可引发严重疾病类鼻疽的环境细菌。最近，在澳大利亚汤斯维尔市类鼻疽的一个临床重点区域——城堡山周围的天然地下水渗出点，报告了高比例的存活类鼻疽伯克霍尔德菌。本研究旨在扩展先前的发现，以确定昆士兰州北部更多样化的天然地下水渗出点中类鼻疽伯克霍尔德菌的分布范围，从而确定城堡山地下水中该菌的存在是否为孤立事件。对汤斯维尔地区一场强降雨后从天然地下水渗出点采集的水样（n = 26）进行分析，结果显示18个样本的复制品中存在类鼻疽伯克霍尔德菌DNA（69.2% [95%置信区间，51.5至87.0]）。从26个水样中，尽管将预富集样本和原始水样都接种到了选择性培养基上，但仅分离出了一株类鼻疽伯克霍尔德菌，这表明这些分子技术的灵敏度远远超过基于培养的方法。此外，通过分析地表地下水渗出点来确定类鼻疽新的地方流行环境，可能比分析随机土壤样本更有效。本研究表明，季风降雨后类鼻疽发病率较高可能部分是由于接触携带类鼻疽伯克霍尔德菌的地下水源所致，因此可能有必要修改地方流行地区的公共卫生信息。此外，这些发现对类鼻疽的预测模型有影响，有效的模型需要考虑地形和地表水文学数据。
