Singh Avishek, William McBride John Hannan, Govan Brenda, Pearson Mark
Cairns Clinical School, College of Medicine and Dentistry, James Cook University, Cairns, Australia.
College of Public Health, Medical and Vet Sciences, James Cook University, Townsville, Australia.
Int J Mycobacteriol. 2019 Jan-Mar;8(1):48-52. doi: 10.4103/ijmy.ijmy_168_18.
Buruli ulcer (BU), regionally known as the Daintree ulcer or Bairnsdale ulcer is caused by the environmental pathogen Mycobacterium ulcerans (MU). This disease is characterized by extensive and painless necrosis of skin and soft tissue with the formation of large ulcers and has been reported in >33 countries worldwide. This organism is geographically restricted and in Australia, the disease has been reported primarily in coastal Victoria and the Mossman-Daintree areas of northern Queensland. Australia is the only country where nonhuman cases of BU have been confirmed. The common ringtail possums and mountain brushtail possums have been suggested as potential animal reservoirs of MU in coastal Victoria, Australia. The exact mode of transmission of this disease remains unknown.
In this study, we surveyed local fauna from endemic areas of northern Queensland, Australia, for the presence of MU in scat samples. We collected 140 bandicoot, four white-tailed rats, and two possum scat samples from 56 overnight trapping sessions. Samples were examined for the presence of MU DNA by the polymerase chain reaction.
Two out of five samples did not contain a sufficient amount of DNA to detect IS2606 and the ketoreductase B (KR) domain of the mycolactone polyketide synthase gene, which is represented by higher cycle threshold (Ct) values for IS2404 shown in table below. Despite of having desired Ct values for IS2404, one IS2404 positive sample possibly contained DNA of closely related M. ulcerans subspecies with lower copy number of IS2606 that do not commonly cause disease in human. All three targets: IS2404, IS2606 and KR were detected from the remaining two scat samples.
We confirm the presence of M. ulcerans DNA in the scat samples collected from a Buruli ulcer endemic region of Northern Queensland, Australia.
布鲁里溃疡（BU），在当地被称为丹特里溃疡或拜恩斯代尔溃疡，由环境病原体溃疡分枝杆菌（MU）引起。这种疾病的特征是皮肤和软组织出现广泛且无痛的坏死，并形成大溃疡，全球已有超过33个国家报告过该疾病。这种病原体在地理上具有局限性，在澳大利亚，该疾病主要报告于维多利亚州沿海地区以及昆士兰州北部的莫斯曼 - 丹特里地区。澳大利亚是唯一确认有非人类布鲁里溃疡病例的国家。普通环尾袋貂和山地刷尾袋貂被认为是澳大利亚维多利亚州沿海地区MU的潜在动物宿主。该疾病的确切传播方式仍然未知。
在本研究中，我们对澳大利亚昆士兰州北部流行地区的当地动物粪便样本进行了调查，以检测其中是否存在MU。我们通过56次夜间诱捕收集了140份袋狸、4份白尾大鼠和2份负鼠的粪便样本。通过聚合酶链反应检测样本中MU DNA的存在情况。
五个样本中有两个样本所含DNA量不足以检测IS2606以及分枝杆菌内酯聚酮合酶基因的酮还原酶B（KR）结构域，如下表所示，其IS2404的循环阈值（Ct）值较高。尽管一个IS2404阳性样本的IS2404 Ct值符合要求，但可能含有与溃疡分枝杆菌密切相关的亚种DNA，其IS2606拷贝数较低，通常不会在人类中引起疾病。在其余两个粪便样本中检测到了所有三个目标：IS2404、IS2606和KR。
我们证实在从澳大利亚昆士兰州北部布鲁里溃疡流行地区收集的粪便样本中存在溃疡分枝杆菌DNA。
