Amanzougaghene Nadia, Akiana Jean, Mongo Ndombe Géor, Davoust Bernard, Nsana Nardiouf Sjelin, Parra Henri-Joseph, Fenollar Florence, Raoult Didier, Mediannikov Oleg
Unité de Recherche sur les Maladies Infectieuses Tropicales Emergentes (URMITE), Aix-Marseille Université, Marseille, France.
Laboratoire national de santé publique, Brazzaville, République du Congo.
PLoS Negl Trop Dis. 2016 Dec 2;10(12):e0005142. doi: 10.1371/journal.pntd.0005142. eCollection 2016 Dec.
Head lice, Pediculus humanus capitis, occur in four divergent mitochondrial clades (A, B, C and D), each having particular geographical distributions. Recent studies suggest that head lice, as is the case of body lice, can act as a vector for louse-borne diseases. Therefore, understanding the genetic diversity of lice worldwide is of critical importance to our understanding of the risk of louse-borne diseases.
METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the results of the first molecular screening of pygmies' head lice in the Republic of Congo for seven pathogens and an analysis of lice mitochondrial clades. We developed two duplex clade-specific real-time PCRs and identified three major mitochondrial clades: A, C, and D indicating high diversity among the head lice studied. We identified the presence of a dangerous human pathogen, Borrelia recurrentis, the causative agent of relapsing fever, in ten clade A head lice, which was not reported in the Republic of Congo, and B. theileri in one head louse. The results also show widespread infection among head lice with several species of Acinetobacter. A. junii was the most prevalent, followed by A. ursingii, A. baumannii, A. johnsonii, A. schindleri, A. lwoffii, A. nosocomialis and A. towneri.
CONCLUSIONS/SIGNIFICANCE: Our study is the first to show the presence of B. recurrentis in African pygmies' head lice in the Republic of Congo. This study is also the first to report the presence of DNAs of B. theileri and several species of Acinetobacter in human head lice. Further studies are needed to determine whether the head lice can transmit these pathogenic bacteria from person to another.
头虱，即人头虱，存在于四个不同的线粒体分支（A、B、C和D）中，每个分支都有特定的地理分布。最近的研究表明，头虱与体虱一样，可作为虱媒疾病的传播媒介。因此，了解全球范围内虱子的遗传多样性对于我们理解虱媒疾病的风险至关重要。
方法/主要发现：在此，我们报告了对刚果共和国俾格米人头虱进行的首次针对七种病原体的分子筛查结果以及虱子线粒体分支分析。我们开发了两种双链分支特异性实时荧光定量PCR，并鉴定出三个主要的线粒体分支：A、C和D，这表明所研究的头虱具有高度多样性。我们在10只A分支头虱中发现了一种危险的人类病原体——回归热螺旋体，这是回归热的病原体，在刚果共和国尚未有相关报道，并且在一只头虱中发现了泰勒螺旋体。结果还显示头虱被多种不动杆菌广泛感染。琼氏不动杆菌最为普遍，其次是乌尔辛不动杆菌、鲍曼不动杆菌、约翰逊不动杆菌、辛德不动杆菌、鲁氏不动杆菌、医院不动杆菌和陶氏不动杆菌。
结论/意义：我们的研究首次表明刚果共和国非洲俾格米人的头虱中存在回归热螺旋体。这项研究也是首次报告人头虱中存在泰勒螺旋体和几种不动杆菌的DNA。需要进一步研究以确定头虱是否能将这些致病细菌从一个人传播给另一个人。
