Diversity of mitochondrial genes and predominance of Clade B in different head lice populations in the northwest of Iran

Abstract

Background The head louse, Pediculus humanus capitis, is the most important ectoparasite causing many health problems. Several linkages are presented for this parasite, each representing a particular geographical distribution, prevalence rate, vector competence, susceptibility to pediculicides, and infestation rate. Determining the genetic nature of these linkages is necessary to identify the population structure and also to develop and monitor control programmes against head lice. This study was designed to analyse cox1 and cytb genes and determine the mitochondrial clades in head lice populations in the northwest of Iran. Methods Adult head lice were collected from infested females of Ardabil, East and West Azerbaijan, and Zanjan Provinces from 2016 to 2018. Partial fragments of the mitochondrial genes cox1 and cytb were amplified by PCR and some of the amplicons were sequenced. All confirmed sequences were analysed, and the frequency of each mitochondrial clade was determined in the studied areas. Results A total of 6410 females were clinically examined, and 897 adult head lice were collected from 562 infested cases. Genomic DNA was extracted from 417 samples, and fragments of cox1 and cytb genes were amplified in 348 individuals. Analysis of the 116 sequences showed the 632-bp and 495-bp fragments for cox1 and cytb genes, respectively. The nucleotide and haplotype diversities of cytb and cox1 genes were 0.02261 and 0.589 and 0.01443 and 0.424, respectively. Sequence analysis indicated 6 haplotypes clustered in two clades, A and B. The relative prevalence of clade B was 73% for cytb and 82% for cox1 gene. Haplotypes of clade B were found in all the studied areas, while those of clade A were observed only in rural and suburban areas. Conclusions To our knowledge, this is the first study investigated deeply the field populations of Pediculus and documented two clades in the Middle East. The considerable prevalence of pediculosis in the studied areas requires authorities’ attention to establish effective control and preventive measures. Given the role of cytb in monitoring population groups, application of this marker is suggested for future epigenetic studies to evaluate the factors affecting the abundance of these clades.

Putative native South Amerindian origin of head lice clade F: evidence from head lice nits infesting human shrunken heads

“…Clade A is distributed worldwide; clade D has only been reported in the Democratic Republic of Congo (Congo- Kinshasa ) , the Republic of Congo (Congo-Brazzaville), Zimbabwe and Ethiopia 9 , 19 , 21 . Clade B is observed in America, Western Europe, Australia, north Algeria, South Africa, Saudi Arabia, and Iran 20 , 22 – 25 . Clade F appears to be specific to South America, as it has not been reported elsewhere 19 .…”

Investigation on prevalence, risk factors, and genetic diversity of Pediculus humanus capitis among primary school children

“…To consider more about P. humanus Capitis, evaluating genetic diversity could be helpful. Different researchers showed that Cox1 DNA sequencing, as a mitochondrial gene, could reveal the genetic diversity of head lice (36). The results of our study showed that the most common type of lice among Iraqi students is clade D (44.87%).…”

High levels of pyrethroid resistance and super-kdr mutations in the populations of tropical bed bug, Cimex hemipterus, in Iran

“…The gDNA of the samples was extracted as described before [ 48 , 49 ]. In brief, the samples were stored at −70 °C for 1 h. The frozen bed bugs were then placed individually in 1.5-ml tubes and homogenized in 400 µl of a lysing buffer (100 mM of Tris HCl [pH 8.0], 0.5 mM of NaCl, 10 mM of EDTA, and 1% W/V SDS) with glass beads by the aid of an electric homogenizer.…”