title: First report of L1014F-kdr mutation in Culex pipiens complex from Morocco.
abstract: Mosquitoes of the Culex pipiens complex, competent vectors for West Nile virus (WNV) and Rift Valley fever virus (RVFV) are widely targeted by insecticide treatments. The intensive application of chemical insecticides led to the development of resistance in many insects including Culex pipiens mosquitoes. The absence of data on resistance mechanisms in Morocco allow us to assess the levels of lambda-cyhalothrin resistance and the frequency of the mutated gene L1014F kdr in different forms of Cx. pipiens complex from three regions of Morocco.
  
  
  
  Mosquito adults were reared from immature stages collected in three different regions in Morocco (Tangier, Casablanca and Marrakech). Standard WHO insecticide susceptibility tests were conducted on adults emerged from collected larvae. Specimens were identified as belonging to the Culex pipiens complex using a multiplex PCR assay with diagnostic primers designed from the flanking region of microsatellite CQ11. Identified mosquitoes were then tested for the presence of the L1014F kdr mutation using PCR assay.
  
  
  
  Our results showed that 21% of the tested population has a resistance to lambda-cyhalothrin. The molecular identification of survivors shows that 43% belonged to the Cx. pipiens pipiens and only 9.5% to the Cx. pipiens molestus form. On the other hand, 416 specimens were screened for the L1014F kdr mutation. L1014F mutation was detected in different forms of Cx. pipiens in different sites. The frequency of L1014F mutation was similar between the Cx. pipiens pipiens form and hybrid form, while it was lower in the Cx. pipiens molestus form. The presence of the L1014F kdr allele was significantly associated with resistance to lambda-cyhalothrin in Cx. pipiens pipiens (P < 0.0001) and hybrid form (P < 0.0001).
  
  
  
  Resistance to lambda-cyhalothrin of Cx. pipiens populations appears to be largely due to the L1014F kdr mutation. To our knowledge, the frequencies of L1014F kdr mutation are examined for the first time in natural populations of the Culex pipiens complex in Morocco. These findings will provide important information to propose more adapted vector control measures towards this mosquito species, potential vector of arboviruses.
authors.affiliation: Institut Pasteur du Maroc, Laboratoire des Maladies Vectorielles, Place Louis Pasteur, Casablanca, 20360, Morocco.|Faculté des Sciences et Techniques de Mohammedia, Laboratoire de Virologie Microbiologie & Qualité/Eco-toxicologie & Biodiversité, Université Hassan II de Casablanca, Casablanca, Morocco.
authors.forename: Meriem
authors.initials: M
authors.lastname: Bkhache
authors.affiliation: Institut Pasteur du Maroc, Laboratoire des Maladies Vectorielles, Place Louis Pasteur, Casablanca, 20360, Morocco.
authors.forename: Fatim-Zohra
authors.initials: FZ
authors.lastname: Tmimi
authors.affiliation: Faculté des Sciences et Techniques de Mohammedia, Laboratoire de Virologie Microbiologie & Qualité/Eco-toxicologie & Biodiversité, Université Hassan II de Casablanca, Casablanca, Morocco.
authors.forename: Omar
authors.initials: O
authors.lastname: Charafeddine
authors.affiliation: Institut National d'Hygiène, Laboratoire d'Entomologie Médicale, Rabat, Morocco.
authors.forename: Chafika
authors.initials: C
authors.lastname: Faraj
authors.affiliation: Institut Pasteur, Department of Virology, Arboviruses and Insect Vectors, 25-28 rue du Docteur Roux, Paris, 75724, France.
authors.forename: Anna-Bella
authors.initials: AB
authors.lastname: Failloux
authors.affiliation: Institut Pasteur du Maroc, Laboratoire des Maladies Vectorielles, Place Louis Pasteur, Casablanca, 20360, Morocco. mhammed.sarih@pasteur.ma.
authors.forename: M'hammed
authors.initials: M
authors.lastname: Sarih
mesh_terms: D000818:Animals; D003465:Culex / Q000235:genetics* / Q000821:virology; D017344:Genes, Insect; D007303:Insect Vectors / Q000235:genetics* / Q000821:virology; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides; D018895:Microsatellite Repeats; D009018:Morocco / Q000453:epidemiology; D009154:Mutation; D009570:Nitriles / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011722:Pyrethrins / Q000494:pharmacology; D012295:Rift Valley Fever / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission; D012296:Rift Valley fever virus / Q000302:isolation & purification; D061566:Voltage-Gated Sodium Channels / Q000235:genetics*; D014901:West Nile Fever / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission; D014902:West Nile virus / Q000302:isolation & purification
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; D061566:Voltage-Gated Sodium Channels; C037304:cyhalothrin
keywords: Culex pipiens; L1014F kdr; Lambda-cyhalothrin; Morocco; Resistance