Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Private Bag 20, Hatfield 0028, South Africa.
Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Private Bag 20, Hatfield 0028, South Africa; South African Research Chair of Mammal Behavioural Ecology and Physiology, Department of Zoology and Entomology, University of Pretoria, Private Bag 20, Hatfield 0028, South Africa.
Infect Genet Evol. 2021 Apr;89:104739. doi: 10.1016/j.meegid.2021.104739. Epub 2021 Jan 31.
The importance of haemotropic Mycoplasma (haemoplasma) infections to animal and human health is increasingly recognised. Although wild rodents are known to host these bacteria, haemoplasma prevalence and diversity in small mammals is under-documented, globally. This is due to the reliance on molecular approaches to detect these unculturable, obligate bacteria and to a paucity of assays targeting informative gene regions. We attempted to address these challenges by evaluating the performance of three 16S rRNA PCR assays for detecting Mycoplasma in four African mole-rat species of the family Bathyergidae. This was achieved by screening DNA samples prepared from lung and liver samples of 260 bathyergids, sampled from natural and urban landscapes in the Western Cape Province with one published and two novel conventional PCR assays. Sequence-confirmed Mycoplasma presence guided calculations of the relative sensitivity and specificity of the assays and revealed that 26.5% of the rodents were haemoplasma-positive. Bathyergus suillus sampled near an informal human settlement had a significantly higher infection rate (42%) than the three bathyergid species sampled from natural settings, for which PCR-positivity ranged from 0% to 36%. The 16S rRNA gene phylogeny identified the presence of six Mycoplasma strains in bathyergids that form a novel monophyletic lineage belonging to the haemofelis group, with 16S rRNA and Rnase P gene phylogenies indicating that the bathyergid-associated haemoplasmas were novel and closely related to Mycoplasma coccoides. Assay sensitivity ranged from 60.3% to 76.8% and specificity from 94.8% to 100% and both were highest for the novel assay targeting a ~ 300 bp region of the 16S rRNA gene. Results confirm the presence of novel haemoplasma strains in bathyergid species from South Africa and emphasise the need for expanded studies on haemoplama prevalence, diversity, and transmission routes in other small mammal species from this biodiverse region.
嗜血性支原体（haemoplasma）感染对动物和人类健康的重要性日益得到认识。虽然已知野生啮齿动物是这些细菌的宿主，但全球范围内小型哺乳动物中的嗜血性支原体的流行率和多样性仍未得到充分记录。这是由于依赖分子方法来检测这些不可培养的专性细菌，以及缺乏针对信息丰富的基因区域的检测方法。我们试图通过评估三种 16S rRNA PCR 检测方法在南非西部省自然和城市景观中采样的四种非洲鼹鼠科 Bathyergidae 物种中检测 Mycoplasma 的性能来解决这些挑战。这是通过筛选从 260 只 Bathyergidae 的肺和肝组织样本制备的 DNA 样本来实现的，这些样本使用一种已发表的和两种新的常规 PCR 检测方法进行了检测。序列确认的 Mycoplasma 存在指导了检测方法的相对灵敏度和特异性的计算，并显示出 26.5%的啮齿动物为嗜血性支原体阳性。在一个非正规人类住区附近采样的 Bathyergus suillus 的感染率（42%）明显高于从自然环境中采样的三种鼹鼠科物种，其 PCR 阳性率范围为 0%至 36%。16S rRNA 基因系统发育分析鉴定出在 Bathyergidae 中存在六种 Mycoplasma 菌株，这些菌株形成了一个新的单系谱系，属于 haemofelis 组，16S rRNA 和 Rnase P 基因系统发育表明，与 Bathyergidae 相关的嗜血性支原体是新的，与 Mycoplasma coccoides 密切相关。检测方法的灵敏度范围为 60.3%至 76.8%，特异性范围为 94.8%至 100%，而针对 16S rRNA 基因约 300bp 区域的新检测方法的灵敏度和特异性均最高。结果证实南非 Bathyergidae 物种中存在新型嗜血性支原体菌株，并强调需要在该生物多样性区域的其他小型哺乳动物物种中扩大对嗜血性支原体流行率、多样性和传播途径的研究。
