Esterase and glutathione S-transferase levels associated with synthetic pyrethroid resistance in Hyalomma anatolicum and Rhipicephalus microplus ticks from Punjab, India

2015 ◽  
Vol 66 (1) ◽  
pp. 141-157 ◽  
Author(s):  
Abhijit Nandi ◽  
Jyoti ◽  
Harkirat Singh ◽  
Nirbhay Kumar Singh
2021 ◽  
Vol 53 (3) ◽  
Author(s):  
Achille S. Ouedraogo ◽  
Olivier M. Zannou ◽  
Abel S. Biguezoton ◽  
Kouassi Yao Patrick ◽  
Adrien M. G. Belem ◽  
...  

AbstractSince 2011, period of the livestock invasion by the cattle tick Rhipicephalus microplus in Burkina Faso (BF), tick-control problems were exacerbated. Based on farmer’s reports, most commonly used commercial acaricides were found to be ineffective in Western South part of the country. To investigate the occurrence and extent of such acaricidal ineffectiveness, we performed the standardized larval packet test (LPT) with commercial deltamethrin (vectocid) and cypermethrin (cypertop), on two cattle tick species, the native Amblyomma variegatum and the invasive R. microplus. The resistance ratios (RR) were computed with susceptible Hounde strain of Rhipicephalus geigyi as reference. The R. microplus population showed resistance to the two acaricides tested with the highest lethal concentration (LC) values, and different resistance ratios higher than 4 (deltamethrin: RR50 = 28.18 and RR90 = 32.41; cypermethrin: RR50 = 8.79 and RR90 = 23.15). In the contrary, A. variegatum population was found to be highly susceptible to acaricides tested with low lethal concentrations and resistance ratio values (deltamethrin: RR50 = 0.5 and RR90 = 0.48; cypermethrin: RR50 = 0.68 and RR90 = 0.79). These data demonstrate high synthetic pyrethroid resistance in R. microplus strain, leading to conclude that the acaricide ineffectiveness in tick populations control remains a concern in BF.


2019 ◽  
Vol 79 (2) ◽  
pp. 233-243 ◽  
Author(s):  
Jehan Zeb ◽  
Sándor Szekeres ◽  
Nóra Takács ◽  
Jenő Kontschán ◽  
Sumaira Shams ◽  
...  

Abstract The two most important tick species in Pakistan are Rhipicephalus microplus and Hyalomma anatolicum. When associated with cattle, these have one or three host life cycles, respectively, with potential implications for their population genetics and for their vector role in the transmission of pathogens. To compare the two tick species in this context with molecular-phylogenetic methods, during the present study 123 ticks were collected from cattle in northern Pakistan. Two mitochondrial markers of 36 ticks were molecularly analyzed. All 11 R. microplus specimens had identical cox1 haplotypes, whereas the 25 H. anatolicum specimens had nine cox1 haplotypes. The latter belonged to two distinct phylogenetic lineages with high support. However, in the 16S rRNA gene these differences were less evident. Among the 113 ticks molecularly analyzed for tick-borne protozoa, the sequence of Babesia occultans was successfully amplified from two specimens of H. anatolicum. Theileria annulata was present in both R. microplus (10.4%) and H. anatolicum (27.3%), with significantly higher prevalence rate in the latter species. Only one tick, a H. anatolicum female, was positive in the PCR detecting Trypanosoma spp. Sequencing revealed the presence of a new genotype, with the closest phylogenetic relationship to stercorarian trypanosomes (in particular, to a tick-associated Trypanosoma sp. from Japan). In conclusion, the above differences between R. microplus and H. anatolicum may be partly related to their life cycles involving one host or three hosts, respectively. Among the others, host switching (reducing chances of inbreeding) and shorter periods spent on-host (reducing gene flow between cattle herds) are supposed to be important drivers of cox1 gene diversification in case of H. anatolicum as a three host tick species. These results highlight the importance of studying differences in intraspecific genetic diversity and piroplasm burdens between one host and three host ticks in the local scale. In addition, a Trypanosoma sp. molecularly identified in H. anatolicum is reported here for the first time from South Asia, deserving further evaluation concerning its host and vector species.


Author(s):  
Clerison R Perini ◽  
Christine A Tabuloc ◽  
Joanna C Chiu ◽  
Frank G Zalom ◽  
Regis F Stacke ◽  
...  

Abstract Chrysodeixis includens (Walker, [1858]) is one of the most important defoliator of soybean in Brazil because of its extensive geographical distribution and high tolerance to insecticides compared with other species of caterpillars. Because of this, we conducted bioassays to evaluate the efficacy of pyrethroid λ-cyhalothrin on a C. includens resistant strain (MS) and a susceptible (LAB) laboratory strain. High throughput RNA sequencing (RNA-seq) of larval head and body tissues were performed to identify potential molecular mechanisms underlying pyrethroid resistance. Insecticide bioassays showed that MS larvae exhibit 28.9-fold resistance to pyrethroid λ-cyhalothrin relative to LAB larvae. RNA-seq identified evidence of metabolic resistance in the head and body tissues: 15 cytochrome P450 transcripts of Cyp6, Cyp9, Cyp4, Cyp304, Cyp307, Cyp337, Cyp321 families, 7 glutathione-S-transferase (Gst) genes, 7 α-esterase genes from intracellular and secreted catalytic classes, and 8 UDP-glucuronosyltransferase (Ugt) were overexpressed in MS as compared with LAB larvae. We also identified overexpression of GPCR genes (CiGPCR64-like and CiGPCRMth2) in the head tissue. To validate RNA-seq results, we performed RT-qPCR to assay selected metabolic genes and confirmed their expression profiles. Specifically, CiCYP9a101v1, CiCYP6ae149, CiCYP6ae106v2, CiGSTe13, CiCOE47, and CiUGT33F21 exhibited significant overexpression in resistant MS larvae. In summary, our findings detailed potential mechanisms of metabolic detoxification underlying pyrethroid resistance in C. includens.


2020 ◽  
Author(s):  
Raquel Cossío-Bayúgar ◽  
Estefan Miranda-Miranda ◽  
Francisco Martínez Ibañez ◽  
Verónica Narváez Padilla ◽  
Enrique Reynaud

Abstract Background: Acaricide resistance is a central problem for the control of the cattle tick Rhipicephalus microplus . Genetic changes that confer resistance get fixed in the population, however, the physiological effects and phenotypes of these mutations are not always well understood or characterized. SNPs in the para-sodium channel gene that confer cypermethrin knockdown resistance ( kdr ) were identified in several arthropods, and homologous mutations have been reported in R. microplus populations. To our knowledge, R. microplus populations that have these homologous SNPs have been associated and correlated with pyrethroid resistance but there is no direct physiological evidence that their presence does confer kdr in this organism. Methods: Resistance profiles from resistant and susceptible strains used in this work were obtained using the larval packet discriminating dose assay. The relevant genomic regions of the para-sodium channel of these strains were amplified using standard PCR; SNPs were detected by sequencing the corresponding amplicons. Ovary response to cypermethrin exposure/treatment was evaluated using videometrical analysis. Results: In this work we present historical evidence that the pyrethroid resistance trait is stable in a resistant reference strain after many years without selection, thus suggesting that the primary resistance mechanism is caused by mutations fixed in the population. In our experimental system, the mechanism that allows the maintenance of the contraction of the ovary after treatment with pyrethroids, is likely to be mediated by a change in the structure of the presynaptic para-sodium channel. We found that the resistant strain has the G184C, the C190A and the T2134A mutations in the para-sodium channel gene. SNPs G184C and T2134A have been reported to be genetically linked in resistant populations and are always found together. These mutations were confirmed to be absent in the susceptible strain used as control. Finally, using videometric analysis, we demonstrate that cypermethrin blocks ovary contraction in cypermethrin-susceptible ticks. We also show that ovaries from populations that carry the kdr associated SNPs still contract at cypermethrin concentrations that completely block ovary contraction in the susceptible strain. The configuration of the experimental system excludes a xenobiotic detoxification mechanism. Conclusions: This is the first report that presents physiological evidence that the presence of the G184C, the C190A, and the T2134A mutations in the para-sodium channel correlates with the ability of maintaining muscle contractility in R. microplus when exposed to cypermethrin. These results confirm that these SNPs may confer cypermethrin resistance in this organism by avoiding presynaptic blockage that in turn causes flaccid muscle paralysis that is characteristic of this acaricide. This work also demonstrates that the videometric assay that we previously validated can be used to detect more rapidly than other assays that involve larval mortality kdr -like cypermethrin resistant tick strains, because adult preengorged females can be directly assayed after they are collected on the field without waiting until eggs are laid and the larvae eclose.


2004 ◽  
Vol 39 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Steven M. Valles

A cross-resistant strain of German cockroach, Blattella germanica (L.), (Marietta) expressing multiple resistance mechanisms was subjected to selection pressure with cypermethrin. Resistance to cypermethrin increased incrementally from 3.6-fold in the parental strain to 35-fold after 4 rounds of selection. No significant changes were observed in cytochrome P450 content, aldrin epoxidase activity, α-naphthyl acetate hydrolysis (cytosolic fraction), or glutathione S-transferase (CDNB conjugation) activities. Although no significant differences were observed in cypermethrin metabolism, a trend toward greater detoxification among each successive generation was observed. Furthermore, methoxyresorufin O-demethylase activity (often associated with pyrethroid resistance) increased incrementally with each successive selection iteration. The average knockdown time increased incrementally from 37 min (parental strain) to 177 min, and there was a corresponding increase in the kdr allele frequency from 19% to 99% after 4 rounds of selection. The data indicated that kdr-type nerve insensitivity and enhanced metabolism by cytochromes P450 and hydrolases were the principle mechanisms of resistance after selection with cypermethrin.


2002 ◽  
Vol 362 (2) ◽  
pp. 329-337 ◽  
Author(s):  
John G. VONTAS ◽  
Graham J. SMALL ◽  
Dimitra C. NIKOU ◽  
Hilary RANSON ◽  
Janet HEMINGWAY

A novel glutathione S-transferase (GST)-based pyrethroid resistance mechanism was recently identified in Nilaparvata lugens [Vontas, Small and Hemingway (2001) Biochem. J. 357, 65–72]. To determine the nature of GSTs involved in conferring this resistance, the GSTs from resistant and susceptible strains of N. lugens were partially purified by anion exchange and affinity chromatography. The majority of peroxidase activity, previously correlated with resistance, was confined to the fraction that bound to the affinity column, which was considerably elevated in the resistant insects. A cDNA clone encoding a GST (nlgst1-1) —the first reported GST sequence from Hemiptera with up to 54% deduced amino-acid identity with other insect class I GSTs—was isolated from a pyrethroid-resistant strain. Northern analysis showed that nlgst1-1 was overexpressed in resistant insects. nlgst1-1 was expressed in Escherichia coli, purified and characterized. The ability of the recombinant protein to bind to the S-hexylglutathione affinity matrix, its substrate specificities and its immunological properties confirmed that this GST was one from the elevated subset of N. lugens GSTs. Peroxidase activity of the recombinant nlgst1-1 indicated that it had a role in resistance, through detoxification of lipid peroxidation products induced by pyrethroids. Southern analysis of genomic DNA from the resistant and susceptible strains indicated that GST-based insecticide resistance may be associated with gene amplification in N. lugens.


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