Molecular surveillance of resistance to pyrethroids insecticides in Colombian Aedes aegypti populations

Introduction In Colombia, organochloride, organophosphate, carbamate, and pyrethroid insecticides are broadly used to control Aedes aegypti populations. However, Colombian mosquito populations have shown variability in their susceptibility profiles to these insecticides, with some expressing high resistance levels. Materials and methods In this study, we analyzed the susceptibility status of ten Colombian field populations of Ae. aegypti to two pyrethroids; permethrin (type-I pyrethroid) and lambda-cyhalothrin (type-II pyrethroid). In addition, we evaluated if mosquitoes pressured with increasing lambda-cyhalothrin concentrations during some filial generations exhibited altered allelic frequency of these kdr mutations and the activity levels of some metabolic enzymes. Results Mosquitoes from all field populations showed resistance to lambda-cyhalothrin and permethrin. We found that resistance profiles could only be partially explained by kdr mutations and altered enzymatic activities such as esterases and mixed-function oxidases, indicating that other yet unknown mechanisms could be involved. The molecular and biochemical analyses of the most pyrethroid-resistant mosquito population (Acacías) indicated that kdr mutations and altered metabolic enzyme activity are involved in the resistance phenotype expression. Conclusions In this context, we propose genetic surveillance of the mosquito populations to monitor the emergence of resistance as an excellent initiative to improve mosquito-borne disease control measures.

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The Midgut Microbiota of Colombian Aedes aegypti Populations with Different Levels of Resistance to the Insecticide Lambda-cyhalothrin

Insects ◽

10.3390/insects11090584 ◽

2020 ◽

Vol 11 (9) ◽

pp. 584 ◽

Cited By ~ 1

Author(s):

Andrea Arévalo-Cortés ◽

Ana M. Mejia-Jaramillo ◽

Yurany Granada ◽

Heather Coatsworth ◽

Carl Lowenberger ◽

...

Keyword(s):

Aedes Aegypti ◽

Allelic Frequency ◽

Important Change ◽

Pyrethroid Insecticides ◽

Development Of Resistance ◽

Resistant Phenotype ◽

Lambda Cyhalothrin ◽

Insect Symbionts ◽

Dengue Prevention ◽

Different Levels

Insecticide resistance in Aedes aegypti populations is a problem that hinders vector control and dengue prevention programs. In this study, we determined the susceptibility of Ae. aegypti populations from six Colombian regions to the pyrethroid lambda-cyhalothrin and evaluated the presence of the V1016I mutation in the sodium channel gene, which has been broadly involved in the resistance to this insecticide. The diversity of the gut microbiota of these mosquito populations was also analyzed. Only mosquitoes from Bello were susceptible to lambda-cyhalothrin and presented a lower allelic frequency of the V1016I mutation. Remarkably, there was not an important change in allelic frequencies among populations with different resistance ratios, indicating that other factors or mechanisms contributed to the resistant phenotype. Treatment of mosquitoes with antibiotics led us to hypothesize that the intestinal microbiota could contribute to the resistance to lambda-cyhalothrin. Beta diversity analysis showed significant differences in the species of bacteria present between susceptible and resistant populations. We identified 14 OTUs of bacteria that were unique in resistant mosquitoes. We propose that kdr mutations are important in the development of resistance to lambda-cyhalothrin at low insecticide concentrations but insect symbionts could play an essential role in the metabolization of pyrethroid insecticides at higher concentrations, contributing to the resistant phenotype in Ae. aegypti.

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Mechanisms associated with pyrethroid resistance in populations of Aedes aegypti (Diptera: Culicidae) from the Caribbean coast of Colombia

10.1101/2020.01.23.916577 ◽

2020 ◽

Author(s):

Paula X. Pareja-Loaiza ◽

Liliana Santacoloma Varon ◽

Gabriela Rey Vega ◽

Doris Gómez-Camargo ◽

Ronald Maestre-Serrano ◽

...

Keyword(s):

Aedes Aegypti ◽

Selection Pressure ◽

Pyrethroid Resistance ◽

Control Strategies ◽

Activity Levels ◽

Public Health Importance ◽

Caribbean Coast ◽

Pyrethroid Insecticides ◽

The Caribbean ◽

Great Public Health

AbstractAedes aegypti is the main vector of dengue, chikungunya, and Zika viruses, which are of great public health importance in Colombia. Aedes control strategies in Colombia rely heavily on the use of organophosphate and pyrethroid insecticides, providing constant selection pressure and the emergence of resistant populations. In recent years, insecticide use has increased due to the increased incidence of dengue and recent introductions of chikungunya and Zika. In the present study, pyrethroid resistance was studied across six populations of A. aegypti from the Caribbean coast of Colombia. Susceptibility to λ-cyhalothrin, deltamethrin, and permethrin was assessed, and resistance intensity was determined. Activity levels of enzymes associated with resistance were measured, and the frequencies of three kdr alleles (V1016I, F1534C, V410L) were calculated. Results showed variations in pyrethroid susceptibility across A. aegypti populations and altered enzyme activity levels were detected. The kdr alleles were detected in all populations, with high variations in frequencies: V1016I (frequency ranging from 0.15–0.70), F1534C (range 0.94–1.00), and V410L (range 0.05–0.72). In assays of phenotyped individuals, associations were observed between the presence of V1016I, F1534C, and V410L alleles and resistance to the evaluated pyrethroids, as well as between the VI1016/CC1534/VL410 tri-locus genotype and λ-cyhalothrin and permethrin resistance. The results of the present study contribute to the knowledge of the mechanisms underlying the resistance to key pyrethroids used to control A. aegypti along the Caribbean coast of Colombia.

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Chloride channels in apical membrane patches of stellate cells of Malpighian tubules of Aedes aegypti

Journal of Experimental Biology ◽

10.1242/jeb.204.2.367 ◽

2001 ◽

Vol 204 (2) ◽

pp. 367-378 ◽

Cited By ~ 9

Author(s):

K.R. O'Connor ◽

K.W. Beyenbach

Keyword(s):

Aedes Aegypti ◽

Apical Membrane ◽

Stellate Cells ◽

Malpighian Tubules ◽

Type I ◽

Open Probability ◽

Cl Secretion ◽

Cl Channel ◽

Open Time ◽

Channel Type

Stellate cells of Aedes aegypti Malpighian tubules were investigated using patch-clamp methods to probe the route of transepithelial Cl(−) secretion. Two types of Cl(−) channel were identified in excised, inside-out apical membrane patches. The first Cl(−) channel, type I, had a conductance of 24 pS, an open probability of 0.816+/−0.067, an open time of 867+/−114 ms (mean +/− s.e.m., four patches) and the selectivity sequence I(−)>Cl(−)(much greater than) isethionate>gluconate. The I(−)/Cl(−)>>isethionate>gluconate. The I(−)Cl(−) permeability ratio was 1.48, corresponding to Eisenman sequence I. The type I Cl(−) channel was blocked by 2,2′-iminodibenzoic acid (DPC) and niflumic acid (2-[3-(trifluoromethyl)anilo]nicotinic acid). The removal of Ca(2+) from the Ringer's solution on the cytoplasmic side had no effect on channel activity. The second Cl(−) channel, type II, had a conductance of 8 pS, an open probability of 0.066+/−0.021 and an open time of 7.53+/−1.46 ms (mean +/− s.e.m., four patches). The high density and halide selectivity sequence of the type I Cl(−) channel is consistent with a role in transepithelial Cl(−) secretion under control conditions, but it remains to be determined whether these Cl(−) channels also mediate transepithelial Cl(−) secretion under diuretic conditions in the presence of leucokinin.

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Current Status of Pyrethroids Resistance in Aedes aegypti (Culicidae: Diptera) in Lahore District, Pakistan: A Novel Mechanistic Insight

Journal of Medical Entomology ◽

10.1093/jme/tjab137 ◽

2021 ◽

Author(s):

Saira Nawaz ◽

Hafiz Muhammad Tahir ◽

Muhammad Asif Mahmood ◽

Muhammad Summer ◽

Shaukat Ali ◽

...

Keyword(s):

Aedes Aegypti ◽

Enzyme Level ◽

Laboratory Strain ◽

Current Status ◽

Glutathione S Transferase ◽

Development Of Resistance ◽

Biochemical Assays ◽

Dengue Transmission ◽

Lambda Cyhalothrin ◽

Glutathione S Transferases

Abstract Aedes aegypti (Linnaeus, 1762) is a major vector responsible for dengue transmission. Insecticides are being used as the most effective tool to control vector populations in Lahore, Pakistan. Control of Ae. aegypti is threatened by the development of resistance against insecticides. The current status of insecticide resistance was evaluated against pyrethroids (deltamethrin, cypermethrin, and lambda-cyhalothrin) in different populations of Lahore (Model Town, Mishri Shah, Sadar Cantt, Walton, and Valencia). The susceptibility of the larval and adult populations was tested following the standard WHO guidelines. Moderate to high levels of resistance were found against pyrethroids in the larval (RR50: 3.6–27.2 and RR90: 5–90) and adult populations (percentage mortality < 98%). Biochemical assays revealed a statistically significant increase in the enzyme level in all field populations compared to the laboratory strain. The value of esterase was one-fold higher, monooxygenase was 3.9- to 4.7-fold higher, and glutathione S-transferases was 1.9- to 2.6-fold higher in field populations compared to the laboratory strain. These results depict the presence of resistance against deltamethrin, cypermethrin, and lambda-cyhalothrin in field populations of Lahore mediated by metabolic enzymes i.e. esterases, monooxygenases, and glutathione S-transferase.

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Evaluation of the efficacy of neonicotinoid and pyrethroid insecticides in Diaphorina citri Kuwayama (Hemiptera: Liviidae) populations in Colombia

Revista Colombiana de Ciencias Hortícolas ◽

10.17584/rcch.2018v12i2.8093 ◽

2018 ◽

Vol 12 (2) ◽

pp. 358-368

Author(s):

Augusto Ramírez-Godoy ◽

Gina Puentes-Pérez ◽

Hermann Restrepo-Díaz

Keyword(s):

Tropical Dry Forest ◽

Dry Forest ◽

Asian Citrus Psyllid ◽

Insect Vector ◽

Diaphorina Citri ◽

Pyrethroid Insecticides ◽

Lambda Cyhalothrin ◽

The Mean ◽

Number Of Individuals ◽

Forest Conditions

The Asian citrus psyllid Diaphorina citri is the insect vector of the disease known as huanglongbing (HLB), which is the most devastating disease of citrus crops in the world. The Asian citrus psyllid was officially reported in Colombia in 2007, and a national phytosanitary emergency was declared because of the presence of HLB in 2015. Two different experiments were carried out in two locations (Apulo and Jerusalén, Department of Cundinamarca) in Colombia to evaluate the effectiveness of neonicotinoid (clothianidin, imidacloprid and thiamethoxan) and pyrethroid applications (bifenthrin, deltamethrin and lambda cyhalothrin) on the control of D. citri populations (adults, nymphs and eggs) in ‘Tahiti’ lime trees established under tropical dry forest conditions. In the first experiment, trees were foliarly treated as follows: (1) untreated trees; (2) trees treated with 100 g ha-1 of imidacloprid; (3) trees treated with 60 g ha-1 of bifenthrin; (4) trees treated with 12.5 g ha-1 of deltamethrin and (5) trees treated with a co-formulation of 70 g ha-1 of a neonicotinoid (thiametoxan) and 53 g ha-1 of a pyrethroid (lambda cyhalothrin). In the second experiment, trees were treated with 100 g ha-1 of clothianidin. Foliar insecticide applications were carried out at 0 and 4 weeks after the initiation of treatments (WAT). In the first trial, the control presented a mean number of individuals per flush of ≈1.14, whereas the trees treated with neoinicotinoids and pyrethroids showed 50% fewer individuals (0.53-0.61). For the population of immatures, the number of nymphs was 2.25 nymphs per flush in the control, as compared to 0.82-1.22 individuals observed in the treatments with insecticides. The mean number of eggs was also between 80-100% higher in the control trees (2.37 individuals), as compared to the treated trees (1.14-1.78). In the second trial, the use of clothianidin showed a higher control of eggs. The results suggest that the rotation of neonicotinoids with pyrethroids can be a tool to reduce populations and delay resistance processes in D. citri in citrus trees established under tropical dry forest conditions in Colombia.

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A Trifecta of New Insights into Ovine Footrot for Infection Drivers, Immune Response and Host Pathogen Interactions.

Infection and Immunity ◽

10.1128/iai.00270-21 ◽

2021 ◽

Author(s):

Adam M. Blanchard ◽

Ceri E. Staley ◽

Laurence Shaw ◽

Sean R Wattegedera ◽

Christina-Marie Baumbach ◽

...

Keyword(s):

Immune Response ◽

Type I Collagen ◽

Global Analysis ◽

Bacterial Species ◽

Skin Barrier ◽

Control Measures ◽

Skin Barrier Function ◽

Type I ◽

Bacterial Populations

Footrot is a polymicrobial infectious disease in sheep causing severe lameness, leading to one of the industry’s biggest welfare problems. The complex aetiology of footrot makes in-situ or in-vitro investigations difficult. Computational methods offer a solution to understanding the bacteria involved, how they may interact with the host and ultimately providing a way to identify targets for future hypotheses driven investigative work. Here we present the first combined global analysis of the bacterial community transcripts together with the host immune response in healthy and diseased ovine feet during a natural polymicrobial infection state using metatranscriptomics. The intra tissue and surface bacterial populations and the most abundant bacterial transcriptome were analysed, demonstrating footrot affected skin has a reduced diversity and increased abundances of, not only the causative bacteria Dichelobacter nodosus , but other species such as Mycoplasma fermentans and Porphyromonas asaccharolytica . Host transcriptomics reveals a suppression of biological processes relating to skin barrier function, vascular functions, and immunosurveillance in unhealthy interdigital skin, supported by histological findings that type I collagen (associated with scar tissue formation) is significantly increased in footrot affected interdigital skin comparted to outwardly healthy skin. Finally, we provide some interesting indications of host and pathogen interactions associated with virulence genes and the host spliceosome which could lead to the identification of future therapeutic targets. Impact Statement Lameness in sheep is a global welfare and economic concern and footrot is the leading cause of lameness, affecting up to 70% of flocks in the U.K. Current methods for control of this disease are labour intensive and account for approximately 65% of antibiotic use in sheep farming, whilst preventative vaccines suffer from poor efficacy due to antigen competition. Our limited understanding of cofounders, such as strain variation and polymicrobial nature of infection mean new efficacious, affordable and scalable control measures are not receiving much attention. Here we examine the surface and intracellular bacterial populations and propose potential interactions with the host. Identification of these key bacterial species involved in the initiation and progression of disease and the host immune mechanisms could help form the basis of new therapies.

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The Molecular Interactions of ZIKV and DENV with the Type-I IFN Response

Vaccines ◽

10.3390/vaccines8030530 ◽

2020 ◽

Vol 8 (3) ◽

pp. 530

Author(s):

Rosa C. Coldbeck-Shackley ◽

Nicholas S. Eyre ◽

Michael R. Beard

Keyword(s):

Immune Responses ◽

Molecular Interactions ◽

Molecular Mechanisms ◽

Type I Interferon ◽

Control Measures ◽

Type I ◽

Type I Ifn ◽

Adaptive Immune ◽

Vaccination Strategies ◽

Significant Disease

Zika Virus (ZIKV) and Dengue Virus (DENV) are related viruses of the Flavivirus genus that cause significant disease in humans. Existing control measures have been ineffective at curbing the increasing global incidence of infection for both viruses and they are therefore prime targets for new vaccination strategies. Type-I interferon (IFN) responses are important in clearing viral infection and for generating efficient adaptive immune responses towards infection and vaccination. However, ZIKV and DENV have evolved multiple molecular mechanisms to evade type-I IFN production. This review covers the molecular interactions, from detection to evasion, of these viruses with the type-I IFN response. Additionally, we discuss how this knowledge can be exploited to improve the design of new vaccine strategies.

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Attenuated lymphocyte activation leads to the development of immunotolerance in bovine fetuses persistently infected with bovine viral diarrhea virus†

Biology of Reproduction ◽

10.1093/biolre/ioaa088 ◽

2020 ◽

Vol 103 (3) ◽

pp. 560-571 ◽

Cited By ~ 3

Author(s):

Hanah M Georges ◽

Katie J Knapek ◽

Helle Bielefeldt-Ohmann ◽

Hana Van Campen ◽

Thomas R Hansen

Keyword(s):

Immune System ◽

Bovine Viral Diarrhea Virus ◽

Lymphocyte Activation ◽

Control Measures ◽

Bovine Viral Diarrhea ◽

Type I ◽

Persistently Infected ◽

Diarrhea Virus ◽

Viral Diarrhea ◽

Viral Diarrhea Virus

Abstract Bovine viral diarrhea virus continues to cost the cattle industry millions of dollars each year despite control measures. The primary reservoirs for bovine viral diarrhea virus are persistently infected animals, which are infected in utero and shed the virus throughout their lifetime. The difficulty in controlling the virus stems from a limited understanding of transplacental transmission and fetal development of immunotolerance. In this study, pregnant bovine viral diarrhea virus naïve heifers were inoculated with bovine viral diarrhea virus on day 75 of gestation and fetal spleens were collected on gestational days 82, 97, 190, and 245. Microarray analysis on splenic RNA from days 82 and 97 revealed an increase in signaling for the innate immune system and antigen presentation to T cells in day 97 persistently infected fetuses compared to controls. Reverse transcription quantitative polymerase chain reaction on select targets validated the microarray revealing a downregulation of type I interferons and lymphocyte markers in day 190 persistently infected fetuses compared to controls. Protein was visualized using western blot and tissue sections were analyzed with hematoxylin and eosin staining and immunohistochemistry. Data collected indicate that fetal immunotolerance to bovine viral diarrhea virus developed between days 97 and 190, with mass attenuation of the immune system on day 190 of gestation. Furthermore, lymphocyte transcripts were initially unchanged then downregulated, suggesting that immunotolerance to the virus stems from a blockage in lymphocyte activation and hence an inability to clear the virus. The identification of lymphocyte derived immunotolerance will aid in the development of preventative and viral control measures to implement before or during pregnancy.

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Metabolic responses of muscle to exercise

BSAP Occasional Publication ◽

10.1017/s0263967x00041185 ◽

2004 ◽

Vol 32 ◽

pp. 1-9

Author(s):

B Essén–Gustavsson

Keyword(s):

Treadmill Exercise ◽

Metabolic Response ◽

Capillary Density ◽

Oxidative Capacity ◽

Metabolic Responses ◽

Type I ◽

Cross Sectional ◽

Fibre Type Composition ◽

Metabolic Properties ◽

Biochemical Analyses

AbstractMuscle is a tissue with a great plasticity due to the fact that it is composed of fibres having different contractile and metabolic properties. In horses, muscle metabolic responses to exercise are studied by taking biopsies from the gluteus medius muscle. Histochemical stains are used to identify slow contracting type I fibres and fast contracting type IIA and type IIB fibres and to evaluate fibre areas, capillary supply, oxidative capacity, glycogen and lipid content in a muscle. Biochemical analyses of substrates, metabolites and enzyme activities are performed either on a whole piece of muscle, on pools of fibres or on single fibres of identified type.All fibres contain glycogen whereas lipid is mainly found in type I and type IIA fibres that have smaller cross–sectional areas and a higher oxidative capacity than type IIB fibres. Large variations can be seen in metabolic profile between and within fibre types. The most common muscular adaptation to training is an increase in oxidative capacity, capillary density and an increase in the type IIA/IIB ratio. The order of recruitment of fibres during most types of exercise is from type I to type IIA and type IIB.The higher the intensity of exercise, the faster is the breakdown of glycogen. After racing (1640-2640m), and after high intense treadmill exercise, concentrations of lactate and inosine monophosphate (IMP) are increased in the muscle and concentrations of glycogen, adenosine triphosphate (ATP) and creatine phosphate (CP) decreased. Extremely low ATP and high IMP concentrations especially in some type II fibres are observed after racing.After exercise of low intensity and long duration glycogen and triglyceride stores in muscle are utilised, amino acid metabolism is enhanced and protein degradation may occur. After submaximal treadmill exercise to fatigue and after endurance rides glycogen is degraded and depletion occurs mainly in type I and type IIA fibres.Fibre type composition, substrate sources and differences in metabolic properties among fibres and the extent to which fibres are recruited are all factors that influence the metabolic responses of muscle to exercise. Biochemical analyses on whole muscle must be interpreted with caution since large variations in metabolic response to exercise occur among different fibres.

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224 A GROWTH OF HUMAN BG-1 CANCER CELLS EXPRESSING ESTROGEN RECEPTORS WAS ENHANCED BY SYNTHETIC PYRETHROIDS, LAMBDA-CYHALOTHRIN AND CYPERMETHRIN, VIA AN ESTROGEN RECEPTOR-DEPENDENT SIGNALING PATHWAY

Reproduction Fertility and Development ◽

10.1071/rdv27n1ab224 ◽

2015 ◽

Vol 27 (1) ◽

pp. 201 ◽

Cited By ~ 1

Author(s):

C.-W. Kim ◽

R.-E. Go ◽

K.-C. Choi

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Mtt Assay ◽

Ovarian Cancer Cells ◽

Transcriptional Level ◽

Synthetic Pyrethroids ◽

Dependent Manner ◽

Rt Pcr ◽

Pyrethroid Insecticides ◽

Lambda Cyhalothrin

Synthetic pyrethroids (SP) are the most common pesticides in recent use, which are used as indoor pest control. The widespread use of SPs has resulted in extensive exposure to wildlife and human. Recently some SPs are suspected as endocrine disrupting chemicals (EDC) and have been assessed for their potential estrogenicity by various assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LCT) and cypermethrin (CP), the most commonly used pyrethroid insecticides in Korea, using BG-1 ovarian cancer cells expressing oestrogen receptors (ER). To evaluate the estrogenic activities of two SPs, LCT and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT–PCR). In MTT assay, LCT (10–6 M) and CP (10–5 M) significantly induced the growth of BG-1 cancer cells, 1.61 ± 0.1 and 1.45 ± 0.06 times, respectively, as 17β-oestradiol (E2, 10–9 M, 2.73 ± 0.25 times) did. LCT or CP-induced cell growth was reversed to a control level (DMSO) by addition of ICI 182 720 (10–8 M), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT–PCR results showed that transcriptional level of ERα expression was significantly down-regulated by LCT and CP as in case of E2. Taken together, these results indicate that LCT and CP may possess estrogenic potentials to stimulate ovarian cancer cells expressing ERs via an ER-dependent manner, and these collective results confirm the carcinogenicity of these SP, LCT and CP, in ER-positive cells or tissues.

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