Head lice (Pediculus capitis) live on human hair and may be responsible for pruritus that may lead to high irritation and even wound infection [1]. They are transmitted through proximity with infested persons, or the sharing of combs and hair products [2]. Body lice (Pediculus humanus) live in clothes and may be responsible for the transmission of epidemic typhus, relapsing, and trench fever. Body lice are transmitted through shared clothing or physical contact with infested persons. Pubic lice (Pthirus pubis) are not investigated here, and sections relating to them should be removed [1].
lice are a global problem, whose prevalence remains high due to ineffective control strategies and resistance to common chemical treatments [3]. Resistance to anti-lice so far from several countries including the United States, United Kingdom, Argentina, Australia, Israel, France, and Iran has been reported [3-8]. Due to the sensitivity of the subject, the high prevalence of lice infestation in different parts of the world, spending a lot of money and energy to treat the infection, which has different effects, the study of insect symbiont microorganisms is a new approach in the world [9].
The genus of Wolbachia is a group of obligate and intracellular bacteria in the Anaplasmatacea family of the -Proteobacteria that are closely related to the Rickettsia species [10]. It is one of the most common parasiticmicrobes and is possibly the most common reproductive parasite in the biosphere [11]. Interactions of Wolbachia with its hosts are often complex, and in some cases have evolved to be mutualistic rather than parasitic [12]. Some host species cannot reproduce, or even survive, without Wolbachia colonization [13]. It was estimated infection at least 40-66% of arthropod species are infected with Wolbachia [2, 14-18]. Wolbachia is present in the reproductive tissues, testis, and ovaries, of a wide range of arthropods, and transmitted through the egg cytoplasm to the next generation [19]. It causes cytoplasmic incompatibility between strains and species, parthenogenesis induction, feminization, male-killing, and enhanced fecundity and fertility in their hosts [20]. It is suspected that Wolbachia would play a decisive role in causing reproductive manipulations by interacting with the host proteins [21].
The genus Wolbachia is genetically very diverse based on the sequencing of ftsz and 16S rDNA genes. While eight “subgroups” (A–H) have been identified to date [22-26], only subgroup F has been reported in lice [27]. The Wolbachia surface protein (wsp) is often used for detection and phylogenetic analysis of Wolbachia [28]. The wsp is an eight beta-barrel transmembrane protein that participates in host immune response, cell proliferation, pathogenicity, and controlled cell death program [29]. Wolbachia has been detected in the lice populations from Australia, Canada, USA, and Argentina using the wsp marker [27].
In the current study, Wolbachia has not been detected in lice samples, this could be due to mutations in the Wsp priming sites, hence additional primers should be tried before concluding that Wolbachia is absent. Interestingly, lice samples collected from the USA, Madagascar, and Russia was not infected with Wolbachia using the same marker [30].