03157nas a2200313 4500008004100000022001400041245016900055210006900224260001600293300000900309490000700318520211500325653002802440653001102468653001102479653001302490653002002503653001602523653002602539653003702565100002102602700002002623700001902643700003002662700002202692700002202714700003502736856007202771 2022 eng d a2405-673100aPyrethroid-linked resistance allelic mutations by molecular analysis in wild human head louse (Phthiraptera: Pediculidae) populations from schoolgirls of South Iran0 aPyrethroidlinked resistance allelic mutations by molecular analy cAug-01-2022 a7 pp0 v183 a

Background: Human head louse, Pediculus humanus capitis De Geer, 1767 (Anoplura: Pediculidae), is one of the most frequent ectoparasites infesting Homo sapiens worldwide. Reduced sensitivity to treatment due to genetic mutations, in particular knockdown resistance (kdr) (or target site insensitivity) allele, has led to this infestation prevalence. Molecular characterization of this resistance has a crucial impact on selecting appropriate treatment protocol. The aim of this study was to investigate kdr gene mutations on voltage-sensitive sodium channel (VSSC) among wild head lice samples from Fars province, southern Iran.

Methods: Head lice were collected using plastic detection combs on girls enrolled in public schools from 10 counties in Fars province. The specimens were screened in 10 pools (each pool per county containing 35 specimens), with three pools (30%) being positive. Following species identification with valid entomological keys, 350 (68%) out of 514 randomly collected adult head lice were analyzed after their somatic genomic DNA extraction using Sinaclon kit. Samples were investigated by polymerase chain reactions (PCR), and the amplicon was subsequently sequenced.

Results: Sequence analysis showed that the sodium channel genes in the pooled ectoparasites had two intron and three exon regions. Single (L840F), double (I836L, E837K), and triple novel point mutations (V875L, Q876P, S879V); the last involving two concomitant allelic substitutions; were discovered in the second and third exon regions of head louse DNA on chromosome II from three (30%) counties. Other exon or intron regions remained non-mutated from the remaining seven counties.

Conclusions: The detection of six amino acid substitutions from 30% of examined head lice among infested schoolgirls reveal that mutants are minutely developing. These findings provide further incentive to recapitulate the legitimacy of current control measures and resolve dynamics of resistance in human head louse populations.

10aAmino acid substitution10agenome10ainsect10aKdr gene10aNode of Ranvier10aPediculosis10aPermethrin Resistance10aVoltage-sensitive sodium channel1 aMohammadi, Jalal1 aAlipour, Hamzeh1 aAzizi, Kourosh1 aShahriari-Namadi, Marzieh1 aKalantari, Mohsen1 aEbrahimi, Saeedeh1 aMoemenbellah-Fard, Mohammad, D uhttps://www.sciencedirect.com/science/article/pii/S240567312200016205529nas a2200301 4500008004100000022001400041245010600055210006900161260001600230300001000246490000700256520458500263653001104848653001204859653001704871653001404888653001404902653001204916100002104928700001904949700002004968700002204988700002205010700003005032700002205062700003505084856010805119 2021 eng d a1776-104200aFrequency of pyrethroid resistance in human head louse treatment: systematic review and meta-analysis0 aFrequency of pyrethroid resistance in human head louse treatment cJan-01-2021 a10 pp0 v283 a

Head lice (Pediculus humanus capitis) are one of the most common insects causing infestations in humans worldwide, and infestation is associated with adverse socio-economic and public health effects. The development of genetic insensitivity (e.g., target site insensitivity = knockdown resistance or kdr) to topical insecticides has impaired effective treatment. Therefore, this study was undertaken to review and meta-analyze the frequency of pyrethroid resistance in treated head louse populations from the beginning of 2000 to the end of June 2021 worldwide. In order to accomplish this, all English language articles published over this period were extracted and reviewed. Statistical analyses of data were performed using fixed and random effect model tests in meta-analysis, Cochrane, meta-regression and I2 index. A total of 24 articles from an initial sample size of 5033 were accepted into this systematic review. The mean frequency of pyrethroid resistance was estimated to be 76.9%. In collected resistant lice, 64.4% were homozygote and 30.3% were heterozygote resistant. Globally, four countries (Australia, England, Israel, and Turkey) have 100% kdr gene frequencies, likely resulting in the ineffectiveness of pyrethrin- and pyrethroid-based pediculicides. The highest resistance recorded in these studies was against permethrin. This study shows that pyrethroid resistance is found at relatively high frequencies in many countries. As a result, treatment with current insecticides may not be effective and is likely the cause of increased levels of infestations. It is recommended that resistance status be evaluated prior to insecticide treatment, to increase efficacy.

Résumé

Les poux de tête (Pediculus humanus capitis) sont l’un des insectes les plus courants à l’origine d’infestations chez l’homme dans le monde, et l’infestation est associée à des effets socio-économiques et de santé publique néfastes. Le développement d’une insensibilité génétique (par exemple, l’insensibilité au site cible = résistance knockdown ou kdr) aux insecticides topiques a altéré l’efficacité de leur traitement. Par conséquent, cette étude a été entreprise pour examiner et méta-analyser la fréquence de la résistance aux pyréthroïdes dans les populations de poux de tête étudiées du début 2000 à la fin juin 2021 dans le monde. Pour ce faire, tous les articles en anglais publiés au cours de cette période ont été extraits et examinés. Les analyses statistiques des données ont été effectuées à l’aide de tests de modèles à effets fixes et aléatoires dans la méta-analyse, Cochrane, méta-régression et indice I2. Un total de 24 articles provenant d’un échantillon initial de 5033 ont été acceptés dans cette revue systématique. La fréquence moyenne de la résistance aux pyréthroïdes a été estimée à 76,9 %. Chez les poux résistants collectés, 64,4 % étaient homozygotes résistants et 30,3 % étaient hétérozygotes résistants. À l’échelle mondiale, quatre pays (Australie, Angleterre, Israël et Turquie) ont des fréquences de gène kdr de 100 %, ce qui entraîne probablement une inefficacité des pédiculicides à base de pyréthrine et de pyréthrinoïde. La résistance la plus élevée enregistrée dans ces études était celle contre la perméthrine. Cette étude montre que la résistance aux pyréthroïdes est trouvée à des fréquences relativement élevées dans de nombreux pays. En conséquence, le traitement avec les insecticides actuels peut ne pas être efficace et est probablement la cause d’une augmentation des niveaux d’infestation. Il est recommandé d’évaluer le statut de résistance avant le traitement insecticide, pour augmenter son efficacité.

10aAllele10aControl10aectoparasite10aKdr genes10aPyrethrum10atherapy1 aMohammadi, Jalal1 aAzizi, Kourosh1 aAlipour, Hamzeh1 aKalantari, Mohsen1 aBagheri, Masoumeh1 aShahriari-Namadi, Marzieh1 aEbrahimi, Saeedeh1 aMoemenbellah-Fard, Mohammad, D uhttps://www.parasite-journal.org/articles/parasite/full_html/2021/01/parasite210144/parasite210144.html02662nas a2200229 4500008004100000245016600041210006900207260001300276300001200289490000600301520187400307653001602181653000902197653001502206653003702221100002202258700003002280700001902310700003502329700002002364856004802384 2022 eng d00aPermethrin-associated kdr Mutations through Molecular Analysis of Human Head Lice (Phthiraptera: Pediculidae) Populations in School Children in the South of Iran0 aPermethrinassociated kdr Mutations through Molecular Analysis of cOct 2021 a257-2640 v93 a

Abstract

Background:Human head lice is one of the most invincible neglected skin diseases. The use of pyrethroid insecticides is a standard method of treating the disease, which leads to lice population resistance in the long run. The main aim of the current survey was to screen the biomarkers of permethrin-associated kdr (knockdown resistance) point mutations through molecular analysis of the human head lice populations in primary school children in the south of Iran.
 
Methods: In an experimental study, Field-collected head lice from infested students were fixed in ethanol, identified using valid taxonomic keys, and processed by PCR for kdr mutant studies. Sequencing partial voltage-sensitive sodium channel gene in different head lice populations was subsequently implemented and compared with the permethrin-resistant diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) as the gold standard.
 
Results:Human head lice appeared to reflect kdr point mutations in specimens from the city of Shiraz. At least three amino acid mutations at designated sites of D820E, L840F, and N874G, corresponding to replacements of aspartic acid to glutamic acid, leucine to phenylalanine, and asparagine to glycine, are clear in this representative population, respectively. At the same time, only L840F is reported as a new mutant in this survey.

Conclusion: The ongoing treatment of head lice infested in school children harboring kdr-mutated or permethrin-resistant mutants in Shiraz is risky, illogical, and contrary to the One Health initiative of the World Health Organization. Health executives should thus immediately take the indispensable steps to prohibit further procurement of permethrin

10ainsecticide10aIran10aPermethrin10aVoltage-sensitive sodium channel1 aEbrahimi, Saeedeh1 aShahriari-Namadi, Marzieh1 aShahabi, Saeed1 aMoemenbellah-Fard, Mohammad, D1 aAlipour, Hamzeh uhttps://jhsss.sums.ac.ir/article_47895.html