Transcriptomic analysis of insecticide resistance in the lymphatic filariasis vector Culex quinquefasciatus

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.

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Analisis Spasial Kejadian Filariasi di Kabupaten Demak Jawa Tengah

JURNAL KESEHATAN LINGKUNGAN INDONESIA ◽

10.14710/jkli.17.1.46-51 ◽

2018 ◽

Vol 17 (1) ◽

pp. 46

Author(s):

Nurjazuli Nurjazuli ◽

Hanan Lanang Dangiran ◽

Asty Awiyatul Bari'ah

Keyword(s):

Spatial Analysis ◽

Lymphatic Filariasis ◽

Water Flow ◽

Culex Quinquefasciatus ◽

Index Case ◽

Neglected Tropical Diseases ◽

Observational Research ◽

Positioning System ◽

Tropical Diseases ◽

Cross Sectional

Latar Belakang: Filariasis merupakan salah satu penyakit tular vektor yang kurang mendapatkan perhatian, termasuk kelompok Neglected Tropical Diseases (NTDs). Kabupaten Demak merupakan salah satu wilayah di Propinsi Jawa Tengah yang merupakan daerah endemis filarisis (mf rate>1%). Kejadian filarisis di daerah ini diduga berkaitan dengan kondisi lingkungan fisik dan biologis (nyamuk) yang mempunyai peran penting dalam penyebaran penyakit filarisis. Penelitian ini bertujuan untuk menemukan adanya penderita baru, mengidentifikasi kondisi lingkungan fisik dan biologi yang berkaitan dengan sebaran filarisis di Kabupaten Demak.Matede: Penelitian ini merupakan penelitian observasional dengan rancangan cross-sectional. Sebanyak 30 kasus filariasis dijadikan indek kasus yang selanjutnya dipilih secara purposif sebanyak 140 yang tinggal di sekitar 30 kasus tersebut untuk dilakukan pengamblan darah jari. Observasi lingkungan dilakukan untuk mengidentifikasi kondisi lingkungan (breeding places dan resting places) dari yang diduga sebagai nyamuk vektor filariasis. Penangkapan nyamuk dilakukan di sekitar rumah penderita filariasis. Pengukuran koordinat kasus filariais dilakukan dengan pesawat Geographic Positioning System (GPS). Pemeriksaan darah jadi jari dilakukan di Laboratorium Kesehatan Daerah (LABKESDA) Propinsi Jawa Tengah. Sedang bedah nyamuk dilakukan di Balai Penelitian Vektor Penyakit Banjarnegara. Analisis data dlakukan secara deskriptif, analisis spasial dilakukan dengan software ArcGis 9.3.Hasil: Penelitian ini tidak menemukan penderita baru filarisis (mf rate=0%). Sebanyak 129 ekor nyamuk telah dilakukan pembedahan dengan hasil semuanya negatip cacing filaria. Hasil identifikasi nyamuk menemukan spesies nyamuk Culex quinquefasciatus merupakan nyamuk yang dominan (72,86%) di lokasi penelitian.Terdapat breeding places (40%) berupa genangan air terbuka (SPAL) dan resting places (83,3%) berupa semak-semak di sekitar rumah penderita. Analisis spasial menunjukkan bahwa kasus filariasi hampir menyebar di seluruh wilayah Kaputaen Demak. Daerah cekungan aliran air nampaknya merupakan kondisi dimana kasus filariasis banyak terjadi. Simpulan: Kasus filariasis hampir menyebar di seluruh wilayah Kabupaten Demak dengan konsentrasi lebih banyak pada daerah cekungan aliran air Semarang-Demak. ABSTRACTTitle: Spatial Analysis of Lymphatic Filariasis in Demak Dictric, Central JavaBackground: Lymphatic filariasis (LF) is one of vector related diseaseswhich less attention from goverment, It was classified as Neglected Tropical Diseases (NTDs). Demak District is one of area in Central Jawa which was endemic of LF (mf rate>1%). It may be related to the physical and biologycal environment condition which have important role in the spreading of LF. This research aimed to identify new cases, find mosquitoe vector , and asses the condition of physical and biologycal environment related to the distribuion of LF cases in Demak District. Methods: It was an observational research using cross-sectional design. As more as 30 LF cases defined as index case and then 140 persons living around index case were selected for blood testing of microfilaria. Observation was conducted to assess the presence of breeding and resting places for mosquitoes development. Mosquito collection was conducted around the houses the LF cases early in the morning. Site of LF cases were measured using Geographic Positioning System (GPS) Apparatus. Blood test for identifying microfilaria was performed at Province Health Labotatory of Centra Java. Mosquotoes dissection was performed at Research Institule of Disease Vector Banjarnegara. Data would be analyzed descriptively and spatial analysis was performed using ArcGis 9.3.Results: This research did’t find new cases of filariasis (mf rate=0%). As more as 129 mosquitoes had been dissected and all of them indicated negative of filarial worm. This research showed that Culex quinquefasciatus as dominant mosquitoe species with the proportion of 72,86%. Water puddle (40%) and small three (83,3%) were found as a good habitats located around the house of filariasis cases. Spatial analysis indicated that filariasis cases spread in all over area of Demak Distirct, and It concentated in the area of undergroud water flow of Semarang-DemakConclusion: Lymphatif Filariasis cases were nearly distributed all over area of Demak Distict and It was concentrated in area with underground water flow Semarang-Demak.

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Organophosphorus insecticide resistance in a new strain of Culex quinquefasciatus (Diptera: Culicidae) from Tanga, Tanzania

Bulletin of Entomological Research ◽

10.1017/s0007485300041791 ◽

1993 ◽

Vol 83 (1) ◽

pp. 67-74 ◽

Cited By ~ 3

Author(s):

A. Khayrandish ◽

R.J. Wood

Keyword(s):

Insecticide Resistance ◽

Culex Quinquefasciatus ◽

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Laboratory Culture ◽

Fourth Instar ◽

Resistance Allele ◽

Susceptible Control ◽

The Mean

AbstractFourth instar larvae of a new strain of Culex quinquefasciatus Say from Tanzania (TANGA) were tested for insecticide resistance. Initially, the resistance ratio (RR) to chlorpyrifos was 41.8, to temephos 30.8, to propoxur 3.7. After 2–3 years of laboratory culture, resistance to chlorpyrifos and propoxur had declined (chlorpyrifos 5.7, 3.8; propoxur 1.9, permethrin 1.9). Significant synergism was found between s, s, s-tributyl trithiophosphate (DEF) and chlorphyrifos, reducing the RR from 8.0 to 2.5. Synergism between piperonyl butoxide and permethrin was less than in a susceptible control strain. Twelve esterase isozymes of different relative mobilities (Rm) on polyacrylamide gel electrophoresis were identified, ten of which remained when the strain was reinvestigated two years (approximately 32 generations) later. Null activity for all but one of these bands was observed in some larvae. Four esterase bands (Rm 0.25, 0.27, 0.31, 0.34, designated A2, A3, B2, B3) showed polymorphism in activity, with very intense bands in some larvae. The mean frequency of bands with activity greater than standard, declined as organophosphorus (OP) resistance declined, but resistance was unconnected with the frequency of nulls at these positions. In mass larval assays of in vitro sensitivity of acetylcholinesterase (AChE) to propoxur, the I50 exceeded 10x10−4M, compared with 0.1x10−4M in a reverted resistant strain (RANGOON). Single larvel assays revealed heterogeneity, which was interpreted on the basis of an AChE resistance allele (AceR) with a frequency of 0.23.

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Bioecology, Insecticide Susceptibility and Management of Culex quinquefasciatus Say, 1823: A Major Vector of Lymphatic Filariasis in India

Lymphatic Filariasis ◽

10.1007/978-981-13-1391-2_16 ◽

2018 ◽

pp. 199-210 ◽

Cited By ~ 1

Author(s):

Reji Gopalakrishnan ◽

Vijay Veer

Keyword(s):

Lymphatic Filariasis ◽

Culex Quinquefasciatus ◽

Insecticide Susceptibility

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Transcriptomic analysis of insecticide resistance in the lymphatic filariasis vectorCulex quinquefasciatus

10.1101/589028 ◽

2019 ◽

Author(s):

Walter Fabricio Silva Martins ◽

Craig Stephen Wilding ◽

Alison Taylor Isaacs ◽

Emily Joy Rippon ◽

Karine Megy ◽

...

Keyword(s):

Insecticide Resistance ◽

Lymphatic Filariasis ◽

Fold Increase ◽

Target Site ◽

Detoxification Enzymes ◽

Site Mutation ◽

Public Health Importance ◽

Metabolic Resistance ◽

Vector Borne Diseases ◽

Bendiocarb Resistance

ABSTRACTCulex quinquefasciatusplays an important role in transmission of vector-borne diseases of public health importance, including lymphatic filariasis (LF), as well as many arboviral diseases. Currently, efforts to tackleC. quinquefasciatusvectored diseases are based on either mass drug administration (MDA) for LF, or insecticide-based interventions. Widespread and intensive insecticide usage has resulted in increased resistance in mosquito vectors, includingC. quinquefasciatus. Herein, the transcriptome profile of Ugandan bendiocarb-resistantC. quinquefasciatuswas explored to identify candidate genes associated with insecticide resistance. Resistance to bendiocarb in exposed mosquitoes was marked, with 2.04% mortality following 1h exposure and 58.02% after 4h. Genotyping of the G119SAce-1target site mutation detected a highly significant association (p<0.0001; OR=25) between resistance andAce1-119S. However, synergist assays using the P450 inhibitor PBO or the esterase inhibitor TPP resulted in markedly increased mortality (to ≈80%), suggesting a role of metabolic resistance in the resistance phenotype. Using a novel, custom 60K whole-transcriptome microarray 16 genes significantly overexpressed in resistant mosquitoes were detected, with the P450Cyp6z18showing the highest differential gene expression (>8-fold increase vs unexposed controls). These results provide evidence that bendiocarb-resistance in UgandanC. quinquefasciatusis mediated by both target-site mechanisms and over-expression of detoxification enzymes.

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