Genetic diversity of human head lice and molecular detection of associated bacterial pathogens in Democratic Republic of Congo

Abstract

Background Head louse, Pediculus humanus capitis , is an obligatory blood-sucking ectoparasite, distributed worldwide. Phylogenetically, it occurs in five divergent mitochondrial clades (A–E); each exhibiting a particular geographical distribution. Recent studies suggest that, as in the case of body louse, head louse could be a disease vector. We aimed to study the genetic diversity of head lice collected in the Democratic Republic of the Congo (DR Congo) and to screen for louse-borne pathogens in these lice. Methods A total of 181 head lice were collected from 27 individuals at the Monkole Hospital Center located in Kinshasa. All head lice were genotyped and screened for the presence of louse-borne bacteria using molecular methods. We searched for Bartonella quintana , Borrelia recurrentis , Rickettsia prowazekii , Anaplasma spp., Yersinia pestis , Coxiella burnetii and Acinetobacter spp. Results Among these head lice, 67.4% (122/181) belonged to clade A and 24.3% (44/181) belonged to clade D. Additionally, for the first time in this area, we found clade E in 8.3% (15/181) of tested lice, from two infested individuals. Dual infestation with clades A and D was observed for 44.4% individuals. Thirty-three of the 181 head lice were infected only by different bacterial species of the genus Acinetobacter . Overall, 16 out of 27 individuals were infested (59.3%). Six Acinetobacter species were detected including Acinetobacter baumannii (8.3%), Acinetobacter johnsonii (1.7%), Acinetobacter soli (1.7%), Acinetobacter pittii (1.7%), Acinetobacter guillouiae (1.1%), as well as a new potential species named “ Candidatus Acinetobacter pediculi”. Conclusions To our knowledge, this study reports for the first time, the presence of clade E head lice in DR Congo. This study is also the first to report the presence of Acinetobacter species DNAs in human head lice in DR Congo. Electronic supplementary material The online version of this article (10.1186/s13071-019-3540-6) contains supplementary material, which is available to authorized users.

Molecular identification of head lice collected in Franceville (Gabon) and their associated bacteria

“…This individual could have been in close contact with a person returning from Mali and infested with head lice. Clade E had been recently described in head lice of women from DR Congo [15], but it is frequently identified in West African countries (Mali and Senegal) [17].…”

“…Studies have shown that these species have a low prevalence rate and are less resistant and virulent than A. baumannii [41]. Finally, several species of the genus Acinetobacter have been reported in head lice collected worldwide, particularly in Africa [15,22,28].…”

“…Lice clades were initially determined by qPCR using the A-D and B-C/E duplex primers (Additional file 1: Table S1) [15,17]. For each qPCR run, the final volume of 20 μl was composed of 10 μl of the Roche master mix (Roche Applied Science, Mannheim, Germany), 3 μl of water, 0.5 μl of each primer and probe, 0.5 μl of UDG (uracil DNA glycosylase) and 5 μl lice genomic DNA.…”

“…and C. burnetii. The DNA was screened using qPCRs as previously described [15]. We created a DNA pool with 10 samples of 10 µl each.…”

“…Clade D was found in the Democratic Republic of the Congo (DR Congo), the Republic of the Congo (Congo-Brazzaville), Ethiopia and Zimbabwe [6,7,12,13]. Clade E has been described in Senegal, Mali, DR Congo and found among Nigerian refugees in Algeria and migrant communities living in Bobigny, France [14][15][16][17].…”