scholarly journals Molecular Characterization and Genetic Diversity of Haplogroup E Human Lice in Guinea, West Africa

2021 ◽  
Vol 9 (2) ◽  
pp. 257
Author(s):  
Alissa Hammoud ◽  
Meriem Louni ◽  
Mamadou Cellou Baldé ◽  
Abdoul Habib Beavogui ◽  
Philippe Gautret ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Polymorphisms ◽  
Head Louse ◽  
Public Health Problem ◽  
Head Lice ◽  
Acinetobacter Species ◽  
Pediculus Humanus ◽  
Blood Sucking ◽  
Pathogenic Agents ◽  
First Time

Pediculus humanus capitis, the head louse, is an obligate blood-sucking ectoparasite that occurs in six divergent mitochondrial clades (A, D, B, F, C and E). Several studies reported the presence of different pathogenic agents in head lice specimens collected worldwide. These findings suggest that head louse could be a dangerous vector and a serious public health problem. Herein, we aimed to study the mitochondrial genetic diversity, the PHUM540560 gene polymorphisms profile of head lice collected in Guinea, as well as to screen for their associated pathogens. In 2018, a total of 155 head lice were collected from 49 individuals at the Medicals Centers of rural (Maférinyah village) and urban (Kindia city) areas, in Guinea. Specimens were subjected to a genetic analysis and pathogens screening using molecular tools. Results showed that all head lice belonged to eight haplotypes in the E haplogroup, with six newly identified for the first time. The study of the PHUM540560 gene polymorphisms of our clade E-head lice revealed that 82.5% exhibited the same polymorphism profile as the previously reported clade A-body lice. Screening for targeted pathogens revealed the presence of Acinetobacter spp., while sequencing highlighted the presence of several species, including Acinetobacter baumannii, Acinetobacter nosocomialis, Acinetobacter variabilis, Acinetobacter towneri and for the first time Acinetobacter haemolyticus. Our study is the first to report the existence of the Guinean haplogroup E, the PHUM540560 gene polymorphism profile as well as the presence of Acinetobacter species in head lice collected from Guinea.

scholarly journals Molecular Characterization and Genetic Diversity of Clade E-Human Head Lice from Guinea

2020 ◽  
Author(s):  
Alissa Hammoud ◽  
Meriem Louni ◽  
Mamadou Cellou Baldé ◽  
Abdoul habib Beavogui ◽  
Philippe Gautret ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Polymorphism ◽  
Gene Polymorphisms ◽  
Head Louse ◽  
Public Health Problem ◽  
Human Head ◽  
Head Lice ◽  
Acinetobacter Species ◽  
Pediculus Humanus ◽  
Blood Sucking

Pediculus humanus capitis, the head louse, is an obligate blood-sucking ectoparasite that occurs in six divergent mitochondrial haplogroups (A, D, B, F, C and E), each exhibiting a particular geographic distribution. A few years ago, several studies reported the presence of different pathogenic agents in head lice specimens from different clades collected worldwide. These findings suggest that head louse could be a vector for dangerous diseases and therefore a serious public health problem. Herein, we aimed to study the mitochondrial genetic diversity, the PHUM540560 gene polymorphisms profile of head lice collected in Guinea, as well as to screen for the pathogens present in these lice. In 2018, a total of 155 head lice were collected from 49 individuals at the Medicals Centers of rural (Maférinyah village) and urban (Kindia city) areas, in Guinea. All head lice were subjected to genetic analysis and screened for the presence of several pathogens using molecular tools. The results showed that all head lice belonged to the haplogroups C/E using the duplex qPCR which detects both clades. Standard PCR and sequencing revealed that all specimens belonged to the haplogroup E, including 8 haplotypes, whither 6 new identified for the first time in this study. The study of the PHUM540560 gene polymorphisms in our Guinean head lice revealed that 7/40 (17.5%) of our tested samples exhibit three different polymorphism profiles compared to the clade A-head lice PHUM540560 gene profile, while the remaining specimens 33/40 (82,5%) showed the same PHUM540560 gene polymorphism profile as the previously reported clade A-body lice. Molecular investigations of the targeted pathogens revealed only the presence of Acinetobacter species in 9% of our samples using real time PCR. Sequencing results identified highlighted the presence of several Acinetobacter species, including Acinetobacter baumannii (14.3%), Acinetobacter nosocomialis (14.3%), Acinetobacter variabilis (14.3%), Acinetobacter haemolyticus (7.2%), Acinetobacter towneri (7.2%). Furthermore, a candidate new species of Acinetobacter sp. (7.2%) was detected. Positive specimens were collected from 24,5% individuals in Maférinyah. We also investigated in our study the carbapenem’s-resistant profile of A. baumannii, none of our specimens were positive for the following resistance genes blaOXA-21, blaOXA-24 and blaOXA-58. To the best of our knowledge, our study is the first to report the existence of the Guinean haplogroup E, the PHUM540560 gene polymorphism profile as well as the presence of Acinetobacter species in head lice collected from Guinea.

scholarly journals Presence of the knockdown resistance (kdr) mutations in the head lice (Pediculus humanus capitis) collected from primary school children of Thailand

2020 ◽  
Vol 14 (12) ◽  
pp. e0008955
Author(s):  
Narisa Brownell ◽  
Sakone Sunantaraporn ◽  
Kobpat Phadungsaksawasdi ◽  
Nirin Seatamanoch ◽  
Switt Kongdachalert ◽  
...  
Keyword(s):  
Head Louse ◽  
Point Mutations ◽  
Human Head ◽  
Amino Acid Sequences ◽  
Primary School Children ◽  
Head Lice ◽  
Knockdown Resistance ◽  
Pediculosis Capitis ◽  
Α Subunit ◽  
Blood Sucking

Human head lice are blood-sucking insects causing an infestation in humans called pediculosis capitis. The infestation is more prevalent in the school-aged population. Scalp itching, a common presenting symptom, results in scratching and sleep disturbance. The condition can lead to social stigmatization which can lead to loss of self-esteem. Currently, the mainstay of treatment for pediculosis is chemical insecticides such as permethrin. The extended use of permethrin worldwide leads to growing pediculicide resistance. The aim of this study is to demonstrate the presence of the knockdown resistance (kdr) mutation in head lice populations from six different localities of Thailand. A total of 260 head lice samples in this study were collected from 15 provinces in the 6 regions of Thailand. Polymerase chain reaction (PCR) was used to amplify the α subunit of voltage-sensitive sodium channel (VSSC) gene, kdr mutation (C→T substitution). Restriction fragment length polymorphism (RFLP) patterns and sequencing were used to identify the kdr T917I mutation and demonstrated three genotypic forms including homozygous susceptible (SS), heterozygous genotype (RS), and homozygous resistant (RR). Of 260 samples from this study, 156 (60.00%) were SS, 58 (22.31%) were RS, and 46 (17.69%) were RR. The overall frequency of the kdr T917I mutation was 0.31. Genotypes frequencies determination using the exact test of Hardy-Weinberg equilibrium found that northern, central, northeastern, southern, and western region of Thailand differed from expectation. The five aforementioned localities had positive inbreeding coefficient value (Fis > 0) which indicated an excess of homozygotes. The nucleotide and amino acid sequences of RS and RR showed T917I and L920F point mutations. In conclusion, this is the first study detecting permethrin resistance among human head lice from Thailand. PCR-RFLP is an easy technique to demonstrate the kdr mutation in head louse. The data obtained from this study would increase awareness of increasing of the kdr mutation in head louse in Thailand.

Bacterial Symbiotes, Their Presence in Head Lice, and Potential Treatment Avenues

2006 ◽  
Vol 10 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Craig N. Burkhart ◽  
Craig G. Burkhart
Keyword(s):  
Head Louse ◽  
Human Head ◽  
Blood Feeding ◽  
Symbiotic Bacteria ◽  
Head Lice ◽  
Pediculus Humanus ◽  
Toxic Agents ◽  
Anatomic Localization

Background: Pediculus humanus capitis (head lice) belongs to the order Anoplura, which are blood-feeding ectoparasites that live on human hair. Within these insects reside symbiotic bacteria that enable the insect to flourish on dietary sources of limited nutritional value. These symbiotic bacteria are essential to the survival of the insect. Objective: To assess the feasibility of treating head lice by altering their symbiotic bacteria. Methods: In addition to a literature review of the expanded role of symbiotic bacteria in other organisms, the anatomic localization of their presence in human head lice and molecular characterization of the head louse symbiont were analyzed. Results: Anatomically, the bacterial symbiotes are localized to the midgut mycetome in males and the ovaries in females. The 16S ribosomal ribonucleic acid phylogenetic analysis was presented. Features of this bacterial symbiote may make this symbiont accessible as a target for pediculocidal and ovicidal therapy by altering its habitat and existence. Conclusions: An understanding of the nature of bacterial symbiotes of head lice might lead to alternative strategies for eradication or inhibition of these necessary bacteria, thereby controlling head lice with less toxic agents than conventional insecticides, to which the organism continues to increase its resistance.

Head Louse Feces: Chemical Analysis and Behavioral Activity

2019 ◽  
Author(s):  
F G Galassi ◽  
M I Picollo ◽  
P Gonzalez-Audino
Keyword(s):  
Acetic Acid ◽  
Head Louse ◽  
Skin Irritation ◽  
Human Head ◽  
Behavioral Activity ◽  
Volatile Components ◽  
Head Lice ◽  
Pediculus Humanus ◽  
Secondary Infections

Abstract Human head lice Pediculus humanus capitis (De Geer) (Phthiraptera: Pediculidae) are insect parasites closely associated with humans, feeding on the blood of their hosts and causing them skin irritation and probable secondary infections. Despite being a severe nuisance, very few studies have reported on intraspecific chemical communication in head lice. Here, we evaluated the attractive response of head lice to the volatile compounds and solvent extracts from their feces. We also chemically analyzed the main volatile components of these feces and those of the feces’ extracts. Head lice were attracted to the methanol extract of their feces but not to the hexane or dichloromethane extracts, suggesting the polar nature of bioactive chemicals present in head louse feces. Follow-up chemical identifications, in fact, showed the presence of hypoxanthine, uric acid, and another purine tentatively identified as either guanine or iso-guanine. Additionally, head lice were significantly attracted by volatiles emitted from samples containing feces. The volatiles emanated from feces alone contained 19 identified substances: 2-pentanone, hexanal, heptanal, 3-methyl-3-buten-1-ol, octanal, sulcatone, nonanal, acetic acid, 2-ethyl-1-hexanol, decanal, 1-octanol, butyric acid, 1-nonanol, hexanoic acid, octanoic acid, 2,6-dimethyl-7-octen-2-ol, 2-undecanone, geranylacetone, and hexadecane. The major compounds found were decanal, nonanal, hexanal, and acetic acid, together representing approximately 60% of the identified compounds. This work represents the first chemical evidence of intraspecies communication among head lice. The results support the existence of active substances present in the feces of P. humanus capitis that may be involved in its aggregation behavior.

Genetic Diversity of Pediculus humanus capitis (Phthiraptera: Pediculidae) in Peninsular Malaysia and Molecular Detection of Its Potential Associated Pathogens

2019 ◽  
Vol 57 (3) ◽  
pp. 915-926
Author(s):  
Aida Syafinaz Mokhtar ◽  
Yee Ling Lau ◽  
John-James Wilson ◽  
Noraishah Mydin Abdul-Aziz
Keyword(s):  
Genetic Diversity ◽  
Dna Barcoding ◽  
Pathogenic Bacteria ◽  
Peninsular Malaysia ◽  
Molecular Evidence ◽  
Head Lice ◽  
Pediculus Humanus Capitis ◽  
Accurate Identification ◽  
Pediculosis Capitis ◽  
Pediculus Humanus

Abstract Pediculosis capitis caused by Pediculus humanus capitis (De Geer) is endemic all over the world, and children are mostly affected, particularly those living in overcrowded institutions. Several studies have shown that P. h. capitis carried human pathogenic bacteria, suggesting the potential role of head lice in the transmission of pathogens to humans. In this study, we determined the genetic diversity of head lice collected from welfare homes sheltering underprivileged children by using DNA barcoding and demonstrated the presence of Acinetobacter spp., Serratia marcescens, and Staphylococcus aureus in head lice, which have never been investigated before in Malaysia. Cox1 DNA barcoding identified the head lice, P. h. capitis collected from welfare homes across two geographical areas of Peninsular Malaysia as belonging to clades A, B, and D. Acinetobacter bacteria: Acinetobacter guillouiae, Acinetobacter junii, Acinetobacter baumannii, and Acinetobacter nosocomialis were detected in head lice belonging to clades A and also D. In addition, DNA from S. marcescens and S. aureus were also detected in both clades A and D. To our knowledge, this is the first report on the genetic diversity of head lice in Malaysia through DNA barcoding, as well as the first to provide molecular evidence on the type of bacteria occurring in head lice in Malaysia. It is anticipated that the DNA barcoding technique used in this study will be able to provide rapid and accurate identification of arthropods, in particular, medically important ectoparasites.

Pyrethroid Pediculicide Resistance of Head Lice in Canada Evaluated by Serial Invasive Signal Amplification Reaction

2010 ◽  
Vol 14 (3) ◽  
pp. 115-118 ◽  
Author(s):  
Danielle Marcoux ◽  
Kathleen G. Palma ◽  
Nalini Kaul ◽  
Hilliary Hodgdon ◽  
Andrea Van Geest ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Signal Amplification ◽  
Head Louse ◽  
Human Head ◽  
The United States ◽  
Head Lice ◽  
Pediculus Humanus Capitis ◽  
Pediculus Humanus ◽  
S Allele ◽  
Amplification Reaction

Background: Most people in the United States and Canada with pediculosis will be treated with neurotoxic pediculicides containing pyrethrins or pyrethroids. Their widespread use led to significant resistance reported from various countries. Although treatment failures are frequently observed in Canada, the resistance frequency to pyrethroid pediculicide of human head lice (Pediculus humanus capitis) has not been determined. Objective: To determine the knockdown resistance ( kdr) allele frequency in human head louse populations in Canada. Methods: Patients infested with Pediculus humanus capitis, aged 4 to 65 years, residents of Ontario, Quebec, and British Columbia, were participants. Head lice were collected by combing and picking the enrolled subjects' hair. Lice were analyzed by serial invasive signal amplification reaction (SISAR) for genotyping the T917I mutation of lice indicating permethrin resistance. The permethrin-resistant kdr allele (R allele) frequency could then be evaluated in the head lice collected in Canada. Results: Of the head louse populations analyzed, 133 of 137 (97.1%) had a resistant (R) allele frequency, whereas only 4 of 137 (2.9%) had a susceptible (S) allele frequency. Conclusions: The 97.1% resistant (R) allele frequency in head lice from Canada could explain the treatment failures encountered with pyrethrin and pyrethroid pediculicide treatments in Canadian populations infested with Pediculus humanus capitis as the latter will not be eliminated by those pediculicides.

First Determination of Pyrethroid Knockdown Resistance Alleles in Human Head Lice (Phthiraptera: Pediculidae) From Chile

2019 ◽  
Vol 56 (6) ◽  
pp. 1698-1703 ◽  
Author(s):  
Gonzalo Roca-Acevedo ◽  
Carmen Paz del Solar Kupfer ◽  
Paulina Dressel Roa ◽  
Ariel Ceferino Toloza
Keyword(s):  
Binding Sites ◽  
Selective Pressure ◽  
Pyrethroid Resistance ◽  
Public Health Problem ◽  
Human Head ◽  
Head Lice ◽  
Pediculus Humanus Capitis ◽  
Over The Counter ◽  
Pediculus Humanus

AbstractThe infestation with the human ectoparasite, Pediculus humanus capitis (De Geer), is a common public health problem affecting schoolchildren worldwide. In Chile, the main active ingredients present in the over-the-counter pediculicides contain pyrethroids. Despite the extended use of these products, there is no evidence of the insecticide resistance status of the head lice geographically located in Chile. The most extended resistant mechanism of pyrethroids consists of the target site insensitivity (Kdr) determined by the presence of mutations linked to insecticide-binding sites in the voltage-sensitive sodium channel. T917I is recognized as the main mutation in head lice, and detection is considered to be a biomarker of resistance. The goal of the present study was to detect the presence and distribution of T917I mutation in five geographic locations of Chile. All five geographically selected louse populations had a frequency of pyrethroid resistance genes that ranged from 36 to 77%, and 94.9% of the collected head lice had one or two T917I mutant alleles. Moreover, the frequency of the aggregate resistant alleles was 50.5%. This is the first evidence that head lice in Chile had the mutations commonly associated with the resistance to pyrethroids. Moreover, the overrepresentation of heterozygotes in the studied populations suggests that head lice in Chile are currently under active selective pressure.

scholarly journals Formulation of Herbal Shampoo against Head Louse (Pediculus humanus capitis De Geer)

2020 ◽  
Vol 8 (1) ◽  
pp. 74-80
Author(s):  
. Deeksha ◽  
Rishabha Malviya ◽  
Pramod K. Sharma ◽  
Dharmendra Singh ◽  
Akanksha Sharma
Keyword(s):  
Surface Tension ◽  
Head Louse ◽  
Physical Appearance ◽  
Solid Content ◽  
Head Lice ◽  
Wetting Ability ◽  
Pediculus Humanus ◽  
Foaming Property ◽  
Soxhlet Apparatus ◽  
Ph Range

Background: Natural herbal shampoos are appealing to the consumers as they contain natural herbs without any harmful effects. The shampoo is used to remove dirt or other debris from hairs. Natural herbs are used in a herbal shampoo, which becomes more beneficial, safe, or efficacious than synthetic ones. Aim: The present study aims to formulate and evaluate a herbal shampoo containing various herbal extracts for anti-lice activity. Materials and Methods: Natural herbs such as neem, hibiscus, henna leaves, amla fruit and reetha epicarp are the components of the natural herbal shampoos used in this study. Soxhlet apparatus was used for water-based extraction of these natural herbs, whereas the maceration process was used for alcohol-based extraction. Nine formulations were prepared and evaluated by using different parameters like physical appearance, viscosity, surface tension, foam volume, pH, solid content, dirt dispersion and wetting time. Results: All nine shampoo formulations were successfully prepared at the pH range of 5.86-6.06. The physical appearance was observed to be between light brown to greenish-brown for F1 to F9 batches. The viscosity of the formulations was found to be between 1.05±0.011 to 0.96±0.011. Mortality of head lice (Lethal time (LT50)) for all the formulations was found in the range of 7.5 min- 52.5 min. Formulation F5 was found to be the best in the context of all the parameters. Formulation F5 showed good foaming property. The wetting ability was found to be good due to reduced surface tension (33.05±0.86); solid content was found to be 1.74% so that it would be easy to wash out from the hair. Conclusion: All the shampoo formulations showed good quality and could be used safely and effectively. These formulations also showed anti-lice activity so they can be used for the problem of head lice.

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

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Mohammad Bagher Ghavami ◽  
Maryam Ghanbari ◽  
Sanaz Panahi ◽  
Behrooz Taghiloo
Keyword(s):  
Head Louse ◽  
Vector Competence ◽  
Mitochondrial Genes ◽  
Effective Control ◽  
Head Lice ◽  
Pediculus Humanus ◽  
Clade B ◽  
Northwest Of Iran ◽  
Adult Head ◽  
Relative Prevalence

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.

Scanning Electron Microscopy of Adult Head Lice (Pediculus Humanus Capitis) with Focus on Clinical Implications

2000 ◽  
Vol 4 (4) ◽  
pp. 181-185 ◽  
Author(s):  
Craig N. Burkhart ◽  
Craig G. Burkhart ◽  
William T. Gunning
Keyword(s):  
Defense Mechanisms ◽  
Developmental Stages ◽  
Head Louse ◽  
Electron Microscopic Examination ◽  
Human Head ◽  
Head Lice ◽  
Electron Microscopic ◽  
Anatomic Structure ◽  
Pediculus Humanus ◽  
Scanning Electron

Background: The incidence of head lice infestations in North America is escalating with an estimated 12 million cases of head lice per year despite the existence of insecticidal therapies. Objective: To evaluate certain characteristics of the human head louse, including their chitinous structure, nymphal developmental stages, legs with claw adaptations, antennae with sensory perceptions, and spiracles by which oxygen exchange occurs, for assessment of possible means to control the spread and growth of this insect. Methods: Scanning electron-microscopic examination of head lice was performed. Results: Newer treatments of head lice must acknowledge defense mechanisms that are based on anatomic structure and physiologic characteristics, details of louse transmission, and the insects' ability to ‘resurrect’ after sham death. Conclusions: An understanding of lice entomology is essential in the pursuit of novel means to control the lice epidemic.

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