scholarly journals Pyrethroid Acaricide Resistance Is Proportional to P-450 Cytochrome Oxidase Expression in the Cattle Tick Rhipicephalus microplus

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Raquel Cossío-Bayúgar ◽  
Francisco Martínez-Ibañez ◽  
Hugo Aguilar-Díaz ◽  
Estefan Miranda-Miranda
Keyword(s):  
Gene Expression ◽  
Pyrethroid Resistance ◽  
Linear Regression Analysis ◽  
Rhipicephalus Microplus ◽  
Cattle Tick ◽  
Synthetic Pyrethroids ◽  
Acaricide Resistance ◽  
Expression Levels ◽  
Field Isolates ◽  
Moderate Resistance

The goal of the present study was to assess the gene expression of xenobiotic metabolizing enzymes (XMEs) Cytochrome P-450 (CYP) and carboxylesterase (CE) related to detoxification of synthetic pyrethroids, plus acetylcholinesterase (AChE), in field isolates of acaricide-resistant Rhipicephalus microplus. The XMEs expression levels were assessed by mRNA measurement using quantitative reverse transcription PCR. The XME expression levels of field-isolated acaricide-resistant ticks were compared against acaricide-susceptible reference ticks used in this study as a gene expression baseline and represented as relative expression units (REU). Field isolates were subjected to toxicological bioassays and determined resistant to all the Pyr acaricides (Pyr), whereas most of them were found susceptible to organophosphorous acaricides (OP), with the exception of three isolates, which exhibited moderate resistance to Diazinon. Significantly higher levels of CYP were detected in pyrethroid-resistance ticks when compared to Su ticks (P<0.01). A linear regression analysis showed that pyrethroid acaricide resistance levels of R. microplus were proportional to the CYP expression levels (correlation coefficient (R):0.85; P<0.05). Analysis on CE expression levels showed only one isolate resistant to Pyr and OP with a statistically significant increase (P<0.01). AChE expression levels showed statistically significant (P<0.01) subexpression in all tick isolates when compared to the susceptible reference. Our results suggest that pyrethroid acaricide resistance in the cattle tick may be diagnosed by measuring the CYP expression levels using quantitative PCR.

scholarly journals Efficacy of two commercial synthetic pyrethroids (cypermethrin and deltamethrin) on Amblyomma variegatum and Rhipicephalus microplus strains of the south-western region of Burkina Faso

2021 ◽  
Vol 53 (3) ◽  
Author(s):  
Achille S. Ouedraogo ◽  
Olivier M. Zannou ◽  
Abel S. Biguezoton ◽  
Kouassi Yao Patrick ◽  
Adrien M. G. Belem ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Pyrethroid Resistance ◽  
Tick Control ◽  
Rhipicephalus Microplus ◽  
Amblyomma Variegatum ◽  
Synthetic Pyrethroid ◽  
Cattle Tick ◽  
Control Problems ◽  
Synthetic Pyrethroids ◽  
Western Region

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.

scholarly journals Physiological evidence that three known mutations in the para-sodium channel gene confer cypermethrin knockdown resistance in Rhipicephalus microplus

2020 ◽  
Author(s):  
Raquel Cossío-Bayúgar ◽  
Estefan Miranda-Miranda ◽  
Francisco Martínez Ibañez ◽  
Verónica Narváez Padilla ◽  
Enrique Reynaud
Keyword(s):  
Sodium Channel ◽  
Pyrethroid Resistance ◽  
Experimental System ◽  
Rhipicephalus Microplus ◽  
Susceptible Strain ◽  
Cattle Tick ◽  
Knockdown Resistance ◽  
Channel Gene ◽  
Sodium Channel Gene ◽  
Physiological Evidence

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.

scholarly journals Characterization of the pyrethroid resistance profile of Rhipicephalus (Boophilus)microplus populations from the states of Rio Grande do Sul and Mato Grosso do Sul, Brazil

2013 ◽  
Vol 22 (3) ◽  
pp. 379-384 ◽  
Author(s):  
Márcia Cristina Mendes ◽  
Fernanda Calvo Duarte ◽  
João Ricardo Martins ◽  
Guilherme Marcondes Klafke ◽  
Leonardo Costa Fiorini ◽  
...  
Keyword(s):  
Pyrethroid Resistance ◽  
Rio Grande ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Synthetic Pyrethroids ◽  
Rio Grande Do Sul ◽  
Mato Grosso ◽  
Cattle Ticks ◽  
Mato Grosso Do Sul

Cattle ticks Rhipicephalus(Boophilus) microplus are mainly controlled in Brazil by means of acaricide products, without any official policies in this regard. Acaricides continue to be sold indiscriminately, and this has contributed towards making the problem of resistance widespread, thus making diagnosis and monitoring of tick resistance essential. Here, bioassays (larval packet test) were performed on tick populations from the states of Rio Grande do Sul and Mato Grosso do Sul regarding their susceptibility to cypermethrin, deltamethrin and flumethrin. All the tick samples tested showed resistance to cypermethrin (10) (resistance factor (RF) ranging from 5.6 to 80.3) and deltamethrin (10) (RF ranging from 2.4 to 83.1). Six out of eight populations were resistant to flumethrin (RF ranging from 3.8 to 8.2). PCR molecular analyses did not show any T2134A mutations in the voltage-gated sodium channel gene, in any of the sampled populations. The results from this study highlight the critical status of resistance of the cattle tick to synthetic pyrethroids in the regions studied. Further studies are needed to identify the mechanisms responsible for the resistant phenotypes observed in the bioassays. This was the first detection of flumethrin resistance in Brazil.

scholarly journals Evaluation of the Efficacy of Acaricides Used to Control the Cattle Tick,Rhipicephalus microplus, in Dairy Herds Raised in the Brazilian Southwestern Amazon

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Luciana G. Brito ◽  
Fábio S. Barbieri ◽  
Rodrigo B. Rocha ◽  
Márcia C. S. Oliveira ◽  
Elisana Sales Ribeiro
Keyword(s):  
Similar Efficacy ◽  
Immersion Test ◽  
Amazon Region ◽  
Rhipicephalus Microplus ◽  
The State ◽  
Cattle Tick ◽  
Dairy Herds ◽  
Synthetic Pyrethroids ◽  
Macrocyclic Lactones

The adult immersion test (AIT) was used to evaluate the efficacy of acaricide molecules used for control ofRhipicephalus micropluson 106 populations collected in five municipalities in the state of Rondônia in the Brazilian South Occidental Amazon region. The analysis of the data showed that the acaricide formulations had different efficacies on the tick populations surveyed. The synthetic pyrethroids (SPs) acaricides were the least effective (48.35–76.84%), followed by SP + organophosphate (OP) associations (68.91–81.47%) and amidine (51.35–100%). For the macrocyclic lactones (MLs), the milbemycin (94.84–100%) was the most effective, followed by spinosad (93.21–100%) and the avermectins (81.34–100%). The phenylpyrazole (PZ) group had similar efficacy (99.90%) to the MLs. Therefore, SP acaricides, including associations with OP, and formulations based on amidine presented low in vitro efficacy to control theR. micropluspopulations surveyed.

scholarly journals Physiological evidence that three known mutations in the para-sodium channel gene confer cypermethrin knockdown resistance in Rhipicephalus microplus

2020 ◽  
Author(s):  
Raquel Cossío-Bayúgar ◽  
Estefan Miranda-Miranda ◽  
Francisco Martínez Ibañez ◽  
Verónica Narváez Padilla ◽  
Enrique Reynaud
Keyword(s):  
Sodium Channel ◽  
Pyrethroid Resistance ◽  
Experimental System ◽  
Rhipicephalus Microplus ◽  
Cattle Tick ◽  
Knockdown Resistance ◽  
Primary Resistance ◽  
Channel Gene ◽  
Sodium Channel Gene ◽  
Physiological Evidence

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 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, ovary contraction resistance to 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 from cypermethrin-susceptible ticks. We also show that ovaries from populations that carry the kdr associated SNPs still contract at cypermethrin concentrations that completely block susceptible ovary contraction. The configuration of the experimental system excludes a xenobiotic detoxification mechanism. Conclusions: This is the first report that presents physiological evidence that the G184C, the C190A, and the T2134A mutations in the para-sodium channel have a phenotype in R. microplus. These results confirm that these SNPs confer cypermethrin resistance in this organism by avoiding presynaptic blockage that in turn cause 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 rapidly detect kdr-like cypermethrin resistant tick strains.

Imprinted Non-Coding RNA Genes, H19 and ZNF215, Are Potential Markers For Two-Year Survival For Acute Myeloid Leukemia Patients With Normal and Abnormal Karyotypes

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2605-2605
Author(s):  
Ming-Yu Yang ◽  
Jan-Gowth Chang ◽  
I-Ya Chen ◽  
Pai-Mei Lin ◽  
Hui-Hua Hsiao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Large Scale ◽  
Conflicts Of Interest ◽  
Linear Regression Analysis ◽  
Altered Expression ◽  
Expression Levels ◽  
Confident Interval ◽  
Acute Myeloid

Abstract Studies in large-scale genome sequencing have shown that only 2% of the mammalian genome encodes mRNAs, but the most part is transcribed as long and short non-coding RNAs (ncRNAs). The ncRNAs with gene regulatory functions are starting to be seen as a common feature of mammalian gene regulation. Genomic imprinting is a form of epigenetic regulation and imprinted genes are silenced in a parental-specific manner. Although the exact mechanism how imprinted ncRNA regulates gene expression remains largely unknown, it is general accepted that imprinted ncRNAs binds to chromatin modifying complexes, such as PRC2, TRX, and G9a, and generates specific silencing of genomic loci both in cis and trans. Imprinting is associated with many human diseases or syndromes (e.g. Prader-Willi, Angelman, Beckwith-Wiedemann, Retts, and Silver-Russell syndromes) and various cancers (e.g. breast, prostate, and colorectal cancers), but its role in leukemogenesis remain elusive. In this present study, the expression of a panel of 24 human imprinted ncRNA genes (AMPD3, C15orf2, COPG2, CPA4, GABRB3, H19, IGF2, IMPACT, INPP5F, L3MBTL, NR3251, NR3252, PEG3-AS, PPP1R9A, PRIM2, RASGRF1, RTL1, SFMBT2, SLC22A3, SNURF, TCEB3C, TSPAN32, ZNF215, ZNF264) and a panel of 66 human histone modifying enzymes (HME) genes was investigated in 68 newly-diagnosed acute myeloid leukemia patients with chromosome normal (AML-CN), 115 AML patients with chromosome abnormal (AML-CA), and 85 healthy individuals using real-time quantitative RT-PCR. Altered expression of 9 imprinted ncRNA genes (C15orf2, COPG2, H19, IGF2, IMPACT, PEG3-AS, PRIM2, SLC22A3, ZNF215) and 16 HME genes were observed. In AML-CN, patients’ survival days are correlated with the expression levels of H19 (p < 0.01), IMPACT (p < 0.05), DNMT3L (p < 0.05) and AURORA (p < 0.01). In AML-CA, patients’ survival days are correlated with the expression levels of PGE3-AS (p < 0.01), PRIM2 (p < 0.01), SLC22A3 (p < 0.05), and ZNF215 (p < 0.01). Multiple linear regression analysis further revealed the expression level of H19 and ZNF215 can be used as predictors for 2-year survival for AML-CN patients (p = 0.002) and AML-CA patients (p = 0.040), respectively. Cox proportional hazard model was used to analyze the hazard ratio (HR) for H19 (HR=0.868, 95.0% Confident Interval: 0.797-0.945, p = 0.001) and ZNF215 (HR=0.904, 95.0% Confident Interval: 0.821-0.995, p =0.040). In addition to survival, analysis has also been performed to correlate patients’ clinical parameters and expression levels of these altered genes and to correlate the expression levels between imprinted ncRNA genes and HME genes (results will be presented at the meeting). From our preliminary results, it is reasonable to hypothesize that loss imprinting of imprinted ncRNA is critical for the leukemogenesis of AML and under CN or CA conditions different ncRNAs are activated and affect different imprinted gene expression and thus leading to different clinical outcomes. Based on our findings, we will further perform in vitro functional analysis to elucidate the functions and mechanisms of these imprinted ncRNAs in AML tumorigenesis. Updated results of these analyzes will be presented at the meeting. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Physiological evidence that three known mutations in the para-sodium channel gene confer cypermethrin knockdown resistance in Rhipicephalus microplus

2020 ◽  
Author(s):  
Raquel Cossío-Bayúgar ◽  
Estefan Miranda-Miranda ◽  
Francisco Martínez Ibañez ◽  
Verónica Narváez Padilla ◽  
Enrique Reynaud
Keyword(s):  
Sodium Channel ◽  
Pyrethroid Resistance ◽  
Experimental System ◽  
Rhipicephalus Microplus ◽  
Susceptible Strain ◽  
Cattle Tick ◽  
Knockdown Resistance ◽  
Channel Gene ◽  
Sodium Channel Gene ◽  
Physiological Evidence

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. Single Nucleotide Polymorphisms (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.

scholarly journals Analysis of Genetic Diversity in Indian Isolates of Rhipicephalus microplus Based on Bm86 Gene Sequence

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 194
Author(s):  
Balasamudram Chandrasekhar Parthasarathi ◽  
Binod Kumar ◽  
Gaurav Nagar ◽  
Haranahally Vasanthachar Manjunathachar ◽  
José de la Fuente ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Amino Acids ◽  
B Cell ◽  
Tick Control ◽  
Rhipicephalus Microplus ◽  
Cattle Tick ◽  
Acaricide Resistance ◽  
Indian States ◽  
B Cell Epitopes ◽  
Indian Isolates

The control of cattle tick, Rhipicephalus microplus, is focused on repeated use of acaricides. However, due to growing acaricide resistance and residues problem, immunization of animals along with limited use of effective acaricides is considered a suitable option for the control of tick infestations. To date, more than fifty vaccine candidates have been identified and tested worldwide, but two vaccines were developed using the extensively studied candidate, Bm86. The main reason for limited vaccine commercialization in other countries is genetic diversity in the Bm86 gene leading to considerable variation in vaccine efficacy. India, with 193.46 million cattle population distributed in 28 states and 9 union territories, is suffering from multiple tick infestation dominated by R. microplus. As R. microplus has developed multi-acaricide resistance, an efficacious vaccine may provide a sustainable intervention for tick control. Preliminary experiments revealed that the presently available commercial vaccine based on the BM86 gene is not efficacious against Indian strain. In concert with the principle of reverse vaccinology, genetic polymorphism of the Bm86 gene within Indian isolates of R. microplus was studied. A 578 bp conserved nucleotide sequences of Bm86 from 65 R. microplus isolates collected from 9 Indian states was sequenced and revealed 95.6–99.8% and 93.2–99.5% identity in nucleotides and amino acids sequences, respectively. The identities of nucleotides and deduced amino acids were 94.7–99.8% and 91.8–99.5%, respectively, between full-length sequence (orf) of the Bm86 gene of IVRI-I strain and published sequences of vaccine strains. Six nucleotides deletion were observed in Indian Bm86 sequences. Four B-cell epitopes (D519-K554, H563-Q587, C598-T606, T609-K623), which are present in the conserved region of the IVRI-I Bm86 sequence, were selected. The results confirm that the use of available commercial Bm86 vaccines is not a suitable option against Indian isolates of R. microplus. A country-specific multi-epitope Bm86 vaccine consisting of four specific B-cell epitopes along with candidate molecules, subolesin and tropomyosin in chimeric/co-immunization format may provide a sustainable option for implementation in an integrated tick management system.

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