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.

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.

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.

Molecular Monitoring of Knockdown Resistance in Head Louse (Phthiraptera: Pediculidae) Populations in Iran

2021 ◽  
Author(s):  
Fereshteh Ghahvechi Khaligh ◽  
Navid Dinparast Djadid ◽  
Mostafa Farmani ◽  
Zahra Asadi Saatlou ◽  
Samira Frooziyan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Head Louse ◽  
Molecular Techniques ◽  
Common Mechanism ◽  
Amino Acid Substitutions ◽  
Head Lice ◽  
Knockdown Resistance ◽  
Resistance Mutations ◽  
Accurate Detection ◽  
Genotype Frequencies

Abstract Knockdown resistance (kdr) is a common mechanism of insecticide resistance in head lice to the conventionally used pyrethroid pediculosis and can be the result of various amino acid substitutions within the voltage-sensitive sodium channel (VSSC). In this study, 54 sequences from varied specimens were investigated to monitor well-known resistance mutations and probable new mutations. The Pediculus humanus capitis de Geer specimens were collected from 13 provinces in Iran. The specimens were stored in 70% ethanol until DNA extraction and PCR amplification of ~900-bp fragment of VSSC. The sequences were analyzed using different bioinformatics software for the detection of well-known kdr substitutions and additional mutations potentially associated with kdr resistance in head lice. There were six new and an old (haplotype I) kdr haplotypes within the Iranian head louse population. K794E, F815I, and N818D amino acid substitutions were reported for the first time. The P813H mutation was the most prevalent amino acid substitution in eight provinces. Among 53 sequences, 26 (49%) were homozygous susceptible, and 27 (51%) were heterozygotes. Thus, 51% of the head lice collected in Iran harbored only the P813H allele. The exact test for the Hardy–Weinberg (H–W) equilibrium showed that genotype frequencies differed significantly from the expectation in East-Azerbaijan and Tehran provinces. Moreover, these populations had an inbreeding coefficient (Fis) <0, indicating the excess of heterozygotes. This observation suggests that the populations of head lice from Iran are currently under active selective pressure. For the rest of the populations, H–W equilibrium and the expectations were significantly in harmony. The results of the current study highlight molecular techniques in the accurate detection of resistance genotypes before their establishment within the head louse population. Accurate detection of resistant genotypes seems to be helpful in decision-making on lice control programs and resistance monitoring and management.

A Rare Case of Coexisting Pediculosis Capitis and Tinea Capitis in a Healthy Adult Female

2021 ◽  
pp. 1-3
Author(s):  
Ahmed H. Nouh ◽  
Mahmoud A. Rageh
Keyword(s):  
Adult Female ◽  
Lupus Erythematosus ◽  
Tinea Capitis ◽  
Healthy Adult ◽  
Head Louse ◽  
Cutaneous Lupus Erythematosus ◽  
Human Head ◽  
Pediculosis Capitis ◽  
Clinical Appearance ◽  
Lichen Planopilaris

Pediculosis capitis is a common condition caused by infestation with the human head louse, <i>Pediculus humanus capitis</i>, and primarily affects children in the age-group of 6–12 years. The most prominent symptom is intense scalp itching, yet moving lice or nonmoving nits may be seen on the scalp and hair. Tinea capitis, also known as scalp ringworm, is a superficial fungal infection caused by keratinophilic fungi termed dermatophytes. Tinea capitis is rare in adults, and its symptoms include hair loss, dry scaly areas, redness, and itching. We here report a case of a rare coexistence between pediculosis capitis and tinea capitis in an otherwise healthy adult female, motivating the search for a possible cause of this rare coexistence and alarming dermatologists to be aware of the modified clinical appearance of this coexistence which could be mistaken with other conditions such as cutaneous lupus erythematosus or lichen planopilaris.

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.

scholarly journals Expansion of the Knockdown Resistance Frequency Map for Human Head Lice (Phthiraptera: Pediculidae) in the United States Using Quantitative Sequencing

2016 ◽  
Vol 53 (3) ◽  
pp. 653-659 ◽  
Author(s):  
Kyle J. Gellatly ◽  
Sarah Krim ◽  
Daniel J. Palenchar ◽  
Katie Shepherd ◽  
Kyong Sup Yoon ◽  
...  
Keyword(s):  
United States ◽  
Human Head ◽  
The United States ◽  
Head Lice ◽  
Knockdown Resistance ◽  
Frequency Map

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.

scholarly journals Prevalence of Pediculosis and Its Predictors among Urban Primary School Children in Kuantan, Pahang

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Muhammad Rusyaidi Azali ◽  
Nor Faiza Mohd Tohit ◽  
Razman Mohd Rus
Keyword(s):  
Rural Communities ◽  
Primary School ◽  
School Children ◽  
Demographic Data ◽  
Female Gender ◽  
Primary School Children ◽  
Head Lice ◽  
Pediculosis Capitis ◽  
Cross Sectional ◽  
Validated Questionnaire

Introduction: Pediculosis capitis among primary school children is always known as the problem of the lower socio-economic class and rural communities. It carries significant consequences to the school children and caregivers. Limited studies have been conducted among the urban populations. Thus, this study aims to investigate the prevalence and predictors of Pediculosis capitis among Urban primary school children in Kuantan. Materials and method: An analytical cross-sectional study using cluster random sampling was carried out in Kuantan, Pahang, Malaysia. A selfadministered validated questionnaire was issued to the participants with purpose to collect socio-demographic data related to age, gender and factors that associated with head lice infestations among primary school children from standard one to six. It was then followed by hair and scalp examination by a well-trained examiners to check the infestation status. The results were analyzed using the chi-squared test and logistic regression analysis. Results: A total of 1347 students from 5 schools  were included in this study. Majority of them were males (53.6%), Malays (61.0%), household income between RM1000-RM2999 (32.1%). The overall prevalence was 9.1% (n=122). Multivariate analysis showed that predictors for pediculosis capitis were female gender (OR= 6.02, 95% CI= 2.97-12.21), Indian ethnicity (OR= 5.55 , 95% CI=3.26-9.45), sibling of more than 5 (OR= 2.72 , 95% CI=1.04-7.12) and contact with infested person (OR=2.42, 95% CI=1.58-3.71). Conclusion: The prevalence of Pediculosis capitis among urban primary school children in Kuantan, Pahang is endemic (9.1%) and predictors are female genders, Indian ethnicity, having siblings of more than 5 and contact with infested person. Hence, preventive measures are necessary to reduce the transmission of head lice among school children.

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