Detection of a knockdown resistance mutation associated with permethrin resistance in the body louse Pediculus humanus corporis by use of melting curve analysis genotyping
Authors: Idir Bitam
Rezak Drali
Jean Marc Rolain
Philippe Brouqui
Samir Benkouiten
Sékéné Badiaga
Journal: Journal of Clinical Microbiology (2012)
Discipline: MICROBIOLOGY
Keywords: Louse-borne diseases; homeless population; genotyping method; permethrin resistance; Pediculus humanus corporis
Affiliations: Aix-Marseille Université, URMITE CNRS-IRD, UMR 6236/198 IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Marseille, France.

Abstract:  Louse-borne diseases are prevalent in the homeless, and body louse eradication has thus far been unsuccessful in this population. We aim to develop a rapid and robust genotyping method usable in large field-based clinical studies to monitor permethrin resistance in the human body louse Pediculus humanus corporis. We assessed a melting curve analysis genotyping method based on real-time PCR using hybridization probes to detect the M815I-T917I-L920F knockdown resistance (kdr) mutation in the paraorthologous voltage-sensitive sodium channel (VSSC) α subunit gene, which is associated with permethrin resistance. The 908-bp DNA fragment of the VSSC gene, encoding the α subunit of the sodium channel and encompassing the three mutation sites, was PCR sequenced from 65 lice collected from a homeless population. We noted a high prevalence of the 3 indicated mutations in the body lice collected from homeless people (100% for the M815I and L920F mutations and 56.73% for the T917I mutation). These results were confirmed by melting curve analysis genotyping, which had a calculated sensitivity of 100% for the M815I and T917I mutations and of 98% for the L920F mutation. The specificity was 100% for M815I and L920F and 96% for T917I. Melting curve analysis genotyping is a fast, sensitive, and specific tool that is fully compatible with the analysis of a large number of samples in epidemiological surveys, allowing the simultaneous genotyping of 96 samples in just over an hour (75 min). Thus, it is perfectly suited for the epidemiological monitoring of permethrin resistance in human body lice in large-scale clinical studies. 

Retracted: No

PubPeer comments:
 In this study, lice were collected from homeless persons in Marseille for genotyping. I have a question about the IRB approval for this study, since homeless persons might be considered to be a  vulnerable population (i.e., vulnerable to coercion), similar to veterans or prisoners in the US, although IRB rules might differ per country. Surprisingly, the IRB approval number listed in this paper (2010-A01406-33) is used for at least 17 studies, including this one. Although all of them involve homeless persons recruited from Marseille shelters, the studies themselves vary in terms of study protocols and treatment sample collection. The studies vary from collecting lice, treating subjects with drug-impregnated underwear, filling out questionnaires, medical exams, to nasal and pharyngeal sampling, skin swabbing, blood draw, rectal samples, sputum collection, and chest X rays. Moreover, the studies were performed from 2011 to 2020, spanning almost 10 years. Would the authors be willing to share the original 2010 ethical approval application here? Did they get approval for all these different studies spanning 10 years, in one single application? There is also confusion about which institution or ethical board approved the study. Some papers state that the study was approved by  our institutional review board , suggesting that this was a number referring to IRB approval by the Aix-Marseille Universitu00e9 and or Institut Hospitalo-Universitaire Mu00e9diterranu00e9e Infection, both listed as author affiliations. But in other papers, the IRB approval number appears to be an ANSM RCB authorization ID, as per  Informed consent was obtained from these subjects, and the study was approved by the u2018u2018Comitu00e9 de Protection des Personnes Sud Mediterranu00e9eu2019u2019 on January, 12, 2011 (ID RCB: 2010-A01406-33) , e.g. as mentioned in PLoS ONE 8(2): e58088. Either way, it would be of interest to take away any concern whether studies on this vulnerable populations were all performed within the original IRB approval scope. Here is the list of 17 papers that all appear to share the same ethical approval number: * Rezak Drali et al. - Journal of Clinical Microbiology (2012) p. 2229u20132233 - DOI: 10.1128 JCM.00808-12 * Rezak Drali et al. - PLoS ONE 8(2): e58088 (2013) - DOI: 10.1371 journal.pone.0058088 * Samir Benkouiten et al. - JAMA Dermatol. 2014;150(3):273-279 (2014) - DOI: 10.1001 jamadermatol.2013.6398 * Rezak Drali et al - Infection, Genetics and Evolution 39 (2016) 225u2013231 - DOI: 10.1016 j.meegid.2016.02.008 * Tran Duc Anh Ly et al. - Emerging Infectious Diseases (2017) - DOI: 10.3201 eid2311.170516 * Tran Duc Anh Ly et al. - Clinical Microbiology and Infection 25 (2019) 249.e1e249.e6 - DOI: 10.1016 j.cmi.2018.04.032 * Tran Duc Anh Ly et al. - Front. Cell. Infect. Microbiol. 9:86 (2019) - DOI: 10.3389 fcimb.2019.00086 * Tran Duc Anh Ly et al. - Journal of Epidemiology and Global Health (2019) - DOI: 10.2991 jegh.k.190510.001 * Tran Duc Anh Ly et al. - Infection and Drug Resistance 2019:12 1139u20131151 - DOI: 10.2147 IDR.S202048 * Nadia Amanzougaghene et al. - Parasites Vectors (2020) 13:177 - DOI: 10.1186 s13071-020-04036-y * Tran Duc Anh Ly et al. - European Journal of Clinical Microbiology Infectious Diseases (2020) - DOI: 10.1007 s10096-020-03889-6 * Tran Duc Anh Ly et al. - Travel Medicine and Infectious Disease 36 (2020) 101768 - DOI: 10.1016 j.tmaid.2020.101768 * Tran Duc Anh Ly et al. - Vector-Borne and Zoonotic Diseases (2020) - DOI: 10.1089 vbz.2019.2603 * Tran Duc Anh Ly et al. - Acta Microbiologica et Immunologica Hungarica (2021) - DOI: 10.1556 030.2021.01346 * Tran Duc Anh Ly et al. - Journal of Epidemiology and Global Health (2021) - DOI: 10.2991 jegh.k.201009.001 * Tran Duc Anh Ly et al. - Journal of Infection Volume 82, Issue 1, January 2021, Pages 60-66 - DOI: 10.1016 j.jinf.2020.11.026 * Tran Duc Anh Ly et al. - European Journal of Clinical Microbiology Infectious Diseases (2021) - DOI: 10.1007 s10096-020-04127-9 ,