1
|
Jiang N, Xie T, Li C, Ma R, Gao A, Liu M, Wang S, Zhou Q, Wei X, Li J, Hu W, Feng X. Molecular assessment of voltage-gated sodium channel (VGSC) gene mutations in Rhipicephalus microplus from Guangxi, China. Parasit Vectors 2024; 17:307. [PMID: 39014392 PMCID: PMC11253372 DOI: 10.1186/s13071-024-06383-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Accepted: 06/29/2024] [Indexed: 07/18/2024] Open
Abstract
BACKGROUND Pyrethroid chemicals are one of the main acaricides used against ticks. Resistance to these chemicals has been reported to be associated with mutations in the voltage-gated sodium channel (VGSC) gene of the Rhipicephalus microplus. This study investigates R. microplus resistance to pyrethroids in Guangxi region of China, marking one of the first research efforts in this area. The findings are intended to provide vital baseline for the effective implementation of localized tick control strategies. METHODS From March to July 2021, 447 R. microplus tick samples were collected from five prefecture-level cities in Guangxi. Allele-specific polymerase chain reaction (AS-PCR) was used to amplify segments C190A and G215T of the domain II S4-5 linker and T2134A of domain III S6 in the VGSC, to detect nucleotide mutations associated with resistance to pyrethroid acaricides. Subsequent analyses were conducted to ascertain the prevalence, types of mutations, and genotypic distributions within the sampled populations. RESULTS Mutations within VGSC gene were identified across all five studied populations of R. microplus, although the mutation rates remained generally low. Specifically, the most prevalent mutation was C190A, observed in 4.9% of the samples (22/447), followed by G215T at 4.0% (18/447), and T2134A at 1.3% (6/447). The distribution of mutations across three critical sites of the VGSC gene revealed four distinct mutation types: C190A, G215T, C190A + G215T, and T2134A. Notably, the single mutation C190A had the highest mutation frequency, accounting for 4.3%, and the C190A + G215T combination had the lowest, at only 0.7%. The analysis further identified seven genotypic combinations, with the wild-type combination C/C + G/G + T/T predominating at a frequency of 90.4%. Subsequently, the C/A + G/G + T/T combination was observed at a frequency of 4.3%, whereas the C/C + T/T + T/T combination exhibited the lowest frequency (0.2%). Additionally, no instances of simultaneous mutations at all three sites were detected. Geographical differences in mutation types were apparent. Both samples from Hechi to Chongzuo cities exhibited the same three mutation types; however, C190A was the most prevalent in Hechi, while G215T dominated in Chongzuo. In contrast, samples from Beihai to Guilin each exhibited only one mutation type: G215T occurred in 12.5% (4/32) of Beihai samples, and C190A in 7.5% (4/53) of Guilin samples. CONCLUSIONS These findings underscore the relatively low frequency of VGSC gene mutations in R. microplus associated with pyrethroid resistance in the Guangxi, China. Moreover, the variation in mutation types and genotypic distributions across different locales highlights the need for regionalized strategies in monitoring and managing pyrethroid resistance in tick populations. This molecular surveillance is crucial for informing targeted control measures and mitigating the risk of widespread resistance emergence.
Collapse
Affiliation(s)
- Na Jiang
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Ting Xie
- Hechi Animal Disease Prevention and Control Center, Hechi, Guangxi, China
| | - Chunfu Li
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Rui Ma
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Ai Gao
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Mengyun Liu
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Shurong Wang
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Qingan Zhou
- Guangxi Center for Animal Disease Control and Prevention, Nanning, Guangxi, China
| | - Xiankai Wei
- Guangxi Center for Animal Disease Control and Prevention, Nanning, Guangxi, China
| | - Jian Li
- College of Life Sciences, Inner Mongolia University, Hohhot, China.
- Basic Medical College, Guangxi University of Chinese Medicine, Nanning, Guangxi, China.
| | - Wei Hu
- College of Life Sciences, Inner Mongolia University, Hohhot, China.
- Department of Infectious Diseases, Huashan Hospital, State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China.
| | - Xinyu Feng
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- One Health Center, Shanghai Jiao Tong University-The University of Edinburgh, Shanghai, 20025, China.
| |
Collapse
|
2
|
Sankar M, Kumar B, Manjunathachar HV, Parthasarathi BC, Nandi A, Neethu CKS, Nagar G, Ghosh S. Genetic Diversity of Rhipicephalus (Boophilus) microplus for a Global Scenario: A Comprehensive Review. Pathogens 2024; 13:516. [PMID: 38921813 PMCID: PMC11206262 DOI: 10.3390/pathogens13060516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/27/2024] Open
Abstract
Rhipicephalus microplus poses a substantial threat to livestock health and agricultural economies worldwide. Its remarkable adaptability to diverse environments and hosts is a testament to its extensive genetic diversity. This review delves into the genetic diversity of R. microplus, employing three pivotal genetic markers: the cytochrome c oxidase I (COX1) gene, ribosomal genes, and microsatellites. The COX1 gene, a crucial tool for genetic characterization and phylogenetic clustering, provides insights into the adaptability of ticks. Ribosomal genes, such as internal transcribed spacer regions (ITS-1 and2) as well as 18S and 28S, are routinely utilized for species differentiation. However, their use is limited due to indels (insertions and deletions). Microsatellites and minisatellites, known for their high polymorphism, have been successfully employed to study populations and genetic diversity across various tick species. Despite their effectiveness, challenges such as null alleles and marker variations warrant careful consideration. Bm86, a well-studied vaccine candidate, exhibits substantial genetic diversity. This diversity directly influences vaccine efficacy, posing challenges for developing a universally effective Bm86-based vaccine. Moreover, the review emphasizes the prevalence of genes associated with synthetic pyrethroid resistance. Identifying single nucleotide polymorphisms in the acaricide-resistant genes of R. microplus has facilitated the development of molecular markers for detecting and monitoring resistance against synthetic pyrethroids. However, mutations in sodium channels, the target site for synthetic pyrethroid, correlate well with the resistance status of R. microplus, which is not the case with other acaricide target genes. This study underscores the importance of understanding genetic diversity in developing effective tick management strategies. The choice of genetic marker should be tailored based on the level of taxonomic resolution and the group of ticks under investigation. A holistic approach combining multiple markers and integrating additional molecular and morphological data may offer a more comprehensive understanding of tick diversity and relationships. This research has far-reaching implications in formulating breeding programs and the development of vaccine against ticks and tick-borne diseases (TTBDs) as well as strategies for the management of resistant ticks.
Collapse
Affiliation(s)
- Muthu Sankar
- Entomology Laboratory, Division of Parasitology, Indian Council of Agricultural Research-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, India; (M.S.); (C.K.S.N.); (G.N.)
| | - Binod Kumar
- Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Bihar Animal Sciences University, Kishanganj 855107, India;
| | - Haranahally Vasanthachar Manjunathachar
- Indian Council of Medical Research-National Institute of Traditional Medicine, Department of Health Research, Govt. of India, Nehru Nagar, Belagavi 590010, India;
| | | | - Abhijit Nandi
- Department of Veterinary Parasitology, West Bengal University of Animal and Fishery Sciences, Kolkata 700037, India;
| | - Chemmangat Kunnath Subramanian Neethu
- Entomology Laboratory, Division of Parasitology, Indian Council of Agricultural Research-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, India; (M.S.); (C.K.S.N.); (G.N.)
| | - Gaurav Nagar
- Entomology Laboratory, Division of Parasitology, Indian Council of Agricultural Research-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, India; (M.S.); (C.K.S.N.); (G.N.)
| | - Srikant Ghosh
- Entomology Laboratory, Division of Parasitology, Indian Council of Agricultural Research-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, India; (M.S.); (C.K.S.N.); (G.N.)
- Indian Veterinary Research Institute, Eastern Regional Station, 37, Belgachia Road, Kolkata 700037, India
| |
Collapse
|
3
|
Pérez-Otáñez X, Vanwambeke SO, Orozco-Alvarez G, Arciniegas-Ortega S, Ron-Garrido L, Rodríguez-Hidalgo R. Widespread acaricide resistance and multi-resistance in Rhipicephalus microplus in Ecuador and associated environmental and management risk factors. Ticks Tick Borne Dis 2024; 15:102274. [PMID: 37918285 DOI: 10.1016/j.ttbdis.2023.102274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/13/2023] [Accepted: 10/16/2023] [Indexed: 11/04/2023]
Abstract
Rhipicephalus microplus is a cattle tick widely distributed in tropical and subtropical areas. Various acaricides are used and applied to control the ticks, but resistance is common. The objectives of this study were to evaluate the spatial distribution of resistance to the most commonly applied acaricides (amitraz, ivermectin, and alpha-cypermethrin) in ticks and assess potential risk factors associated with tick resistance in a strip between ±0.5° latitude of the continental part of Ecuador. Larval package tests were used to evaluate the level of acaricide resistance in 96 cattle farms. The association between 11 farm management and 8 ecological variables and acaricide resistance and multi-resistance was evaluated. Dose-response models were used to study the level of resistance. 72 % (69/96), 70 % (67/96), and 64 % (61/96) of farms had ticks resistant to amitraz, ivermectin, and alpha-cypermethrin, respectively. Multi-resistance was also widespread. Larger herds and dairy farms had a significantly higher probability of resistance for three commonly used acaricides. Environmental factors related to rainfall were also associated with acaricidal resistance presence. Ivermectin resistance was associated with use of the acaricide (OR = 8.9909; 7.7519-10.2300), mean temperature (OR = 1.3205;1.0742-1.6799)), and inversely associated with paddock rotation (OR = 0.1753; 0.0294-0.7836), and precipitation of the wettest month (BIO13) (OR = 0.9903; 0.9839-0.9957); amitraz with use of the acaricide (OR = 4.3934; 3.3679-5.4188), precipitation seasonality (BIO15) (OR=0.9742; 0.9542-0.9925), and precipitation (OR = 0.9995; 0.9994-0.9999); and alpha-cypermethrin with precipitation (OR=0.9995; 0.9990-0.9999) and use of the acaricide (OR = 14.4597; 13.4343-15.4852). In conclusion, acaricide resistance was widespread in our study area. Better-integrated tick management and environmentally friendly control strategies are required to reduce the use of acaricides while limiting tick-associated damage in herds.
Collapse
Affiliation(s)
- Ximena Pérez-Otáñez
- Centre for Earth and Climate research, Earth & Life Institute, UCLouvain, Louvain-la-Neuve, Université catholique de Louvain, Belgium; Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador.
| | - Sophie O Vanwambeke
- Centre for Earth and Climate research, Earth & Life Institute, UCLouvain, Louvain-la-Neuve, Université catholique de Louvain, Belgium
| | - Geoconda Orozco-Alvarez
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| | | | - Lenin Ron-Garrido
- Instituto de Investigación en Zoonosis, Universidad Central del Ecuador, Quito, Ecuador; Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador; Facultad de Ciencias Agrícolas, Universidad Central del Ecuador, Quito, Ecuador
| | - Richar Rodríguez-Hidalgo
- Instituto de Investigación en Zoonosis, Universidad Central del Ecuador, Quito, Ecuador; Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| |
Collapse
|
4
|
van Dalen EMSP, Jansen van Rensburg C. Competitive displacement and acaricide resistance of two Rhipicephalus (Boophilus) species collected on commercial farms in South Africa. EXPERIMENTAL & APPLIED ACAROLOGY 2024; 92:135-149. [PMID: 38110760 PMCID: PMC10803472 DOI: 10.1007/s10493-023-00871-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023]
Abstract
Rhipicephalus (Boophilus) microplus, an invasive species to Africa, and the endemic R. (B.) decoloratus are of high economic importance in the cattle industry. Invasion of the alien species in South Africa has mostly been reported for traditional communal grazing areas where it seemed to be rapid and, in some cases, even replaced the native species. The alien species is also assumed to already be resistant to acaricides upon invasion. The presence of R. (B.) microplus on commercial farms was therefore investigated and resistance screening of both species to field concentrations of cypermethrin, amitraz, and chlorfenvinphos was determined by means of the larval immersion test. Results showed that only 3.7% (of 383) tick collections submitted were R. (B.) microplus populations. A further 1.6% (of 383) showed co-existence of the two species. Comparing the level of resistance to the acaricides between the two species indicated a mean phenotypic resistance of 66.2 and 26.5% of R. (B.) decoloratus populations to cypermethrin and amitraz, respectively. This was significantly lower for R. (B.) microplus, with 23.0 and 4.1% of its populations resistant to cypermethrin and amitraz, respectively. Closed commercial farming areas seemed to have a preventative advantage for the invasion of R. (B.) microplus and displacement of R. (B.) decoloratus by R. (B.) microplus. Regular monitoring of these two species may be of high importance to prevent unnecessary financial losses due to insufficient control and increased awareness of the threat of Asiatic babesiosis vectored by R. (B.) microplus.
Collapse
Affiliation(s)
- Ellie M S P van Dalen
- Department of Zoology & Entomology, University of the Free State, PO Box 339, Bloemfontein, Free State, South Africa.
| | - Candice Jansen van Rensburg
- Department of Zoology & Entomology, University of the Free State, PO Box 339, Bloemfontein, Free State, South Africa
| |
Collapse
|
5
|
Gutiérrez-Wong JR, Rosado-Aguilar JA, Rodríguez-Vivas RI. First report of acaricidal efficacy from plumbagin on larvae of Rhipicephalus microplus and Rhipicephalus sanguineus resistant to conventional acaricides. Exp Parasitol 2023; 255:108632. [PMID: 37832775 DOI: 10.1016/j.exppara.2023.108632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/15/2023]
Abstract
The problem of resistance to acaricides in ticks such as Rhipicephalus microplus and R. sanguineus has motivated the search for control alternatives, such as the use of extracts and secondary metabolites from plants. Plumbagin is a natural product present in plants such as Plumbago zeylanica L., Diospyros kaki, and D. anisandra, of which acaricidal activity has been reported. Therefore, the objective of this study was to evaluate in vitro the acaricidal efficacy of plumbagin on larvae of R. microplus and R. sanguineus resistant to conventional acaricides. Larvae from engorged female ticks, collected from naturally infested dairy cattle and domiciled dogs, in Yucatan, Mexico, were used. The larval packet test and the larval immersion test were performed to detect acaricide susceptibility. Both tick populations were detected as resistant to cypermethrin and amitraz. Then, the modified larval immersion test was used and plumbagin was evaluated at concentrations of 1%, 0.5%, 0.25%, and 0.125% (%w/v), obtaining a mortality of 100% in the four concentrations for both tick species. Subsequently, lower doses of plumbagin were evaluated at concentrations of 0.0625%, 0.03125%, 0.015625% and 0.0078125%, obtaining mortalities of 100 to 36.26% for R. microplus and 100%-5.33% for R. sanguineus. Using Probit analysis, lethal concentrations at 50% (LC50), 99% (LC99) and confidence intervals at 95% (CI95%) were calculated. R. microplus showed a LC50 of 0.011% (CI95%: 0.010-0.011) and LC99 of 0.019% (CI95%: 0.018-0.022). R. sanguineus presented a LC50 of 0.017% (CI95%: 0.015-0.018) and CL99 of 0.031% (CI95%: 0.027-0.036). It was concluded that plumbagin has high acaricidal efficacy against larvae of R. microplus and R. sanguineus resistant to amitraz and cypermethrin. R. microplus larvae were significantly more susceptible to LC50 and LC99 compared to R. sanguineus. This is the first report on the acaricidal efficacy of plumbagin on larvae of R. microplus and R. sanguineus resistant to conventional acaricides.
Collapse
Affiliation(s)
- J R Gutiérrez-Wong
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km15.5, Carretera Mérida-Xmatkuil, C.P. 97000, Mérida, Yucatán, Mexico
| | - J A Rosado-Aguilar
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km15.5, Carretera Mérida-Xmatkuil, C.P. 97000, Mérida, Yucatán, Mexico.
| | - R I Rodríguez-Vivas
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km15.5, Carretera Mérida-Xmatkuil, C.P. 97000, Mérida, Yucatán, Mexico
| |
Collapse
|
6
|
van Dalen EMSP, van Rensburg CJ. Evolution of acaricide resistance of Rhipicephalus decoloratus on commercial farms in South Africa. EXPERIMENTAL & APPLIED ACAROLOGY 2023; 90:339-355. [PMID: 37421565 PMCID: PMC10406697 DOI: 10.1007/s10493-023-00820-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 06/28/2023] [Indexed: 07/10/2023]
Abstract
The development of tick resistance to chemical control plays a major role in the increasing global economic impact of ticks on cattle farming. Reports on acaricide resistance of Rhipicephalus decoloratus, endemic to Africa and South Africa, are relatively few compared to the closely related and globally distributed Rhipicephalus microplus. In South Africa, ectoparasite control became the sole responsibility of each commercial producer when compulsory dipping was phased out from 1984. Different acaricidal management strategies resulted in the simultaneous development of resistance to various acaricide groups. The establishment of a Pesticide Resistance Testing Facility provided the opportunity to test Rhipicephalus (Boophilus) populations, submitted from all over South Africa, for resistance where failure of chemical control was experienced. The number of populations resistant to cypermethrin (CM) was significantly higher than those tested as resistant to amitraz (AM), or chlorfenvinphos (CFVP). No significant difference was found between the number of populations resistant to AM and CFVP. The evolution of R. decoloratus resistance at the end of a 12 year period indicated a stable but high prevalence of 90% overall resistance to CM. The same trend was seen for AM-resistant R. decoloratus populations but at a lower level of just over 40%. In contrast, CFVP resistant R. decoloratus populations showed a decreasing trend with near-total reversion to susceptibility. Multi-resistance was present in more than 50% of populations tested with the highest incidence in the Eastern Cape, KwaZulu-Natal, and Western Cape provinces.
Collapse
Affiliation(s)
- Ellie M S P van Dalen
- Department of Zoology & Entomology, University of the Free State, PO Box 339, Free State, Bloemfontein, South Africa.
| | - Candice Jansen van Rensburg
- Department of Zoology & Entomology, University of the Free State, PO Box 339, Free State, Bloemfontein, South Africa
| |
Collapse
|
7
|
Paucar-Quishpe V, Pérez-Otáñez X, Rodríguez-Hidalgo R, Cepeda-Bastidas D, Pérez-Escalante C, Grijalva-Olmedo J, Enríquez S, Arciniegas-Ortega S, Sandoval-Trávez L, Benavides-Erazo B, Vanwambeke SO, Saegerman C, Ron-Garrido L. An economic evaluation of cattle tick acaricide-resistances and the financial losses in subtropical dairy farms of Ecuador: A farm system approach. PLoS One 2023; 18:e0287104. [PMID: 37384770 PMCID: PMC10309988 DOI: 10.1371/journal.pone.0287104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 05/23/2023] [Indexed: 07/01/2023] Open
Abstract
Estimates of economic losses in cattle due to tick infestations in subtropical areas are limited, such as in Ecuador. Ticks affect animal production and health, but those direct effects are difficult to estimate since financial exercises carried out in farms consider both costs of the inputs and revenues. This study aims to quantify the costs of inputs involved in milk production and to know the role of acaricide treatment in the production costs on dairy farms in subtropical zones using a farming system approach. Regression and classification trees were used to study the relationship between tick control, acaricide resistance and the presence of high level of tick infestation in the farm system. Even though there was no significant direct association between high levels of tick infestation and the presence of acaricide resistance in ticks, a more complex structure for resistances operates in the manifestation of high tick infestation involving levels of farm technology and no acaricide resistance. Farms with higher levels of technology allocate a lower percentage of sanitary expenses to control ticks (13.41%) in comparison to semi-technified (23.97%) and non-technified farms (32.49%). Likewise, more technified and bigger herds have a lower annual expenditure on acaricide treatment (1.30% of the production budget equivalent to 8.46 USD per animal) compared to non-technified farms where it can represent more than 2.74% of the production budget and where the absence of cypermethrin resistance increases the treatment cost to 19.50 USS per animal annually. These results can motivate the development of information campaigns and control programmes targeted to the reality of small and medium farms that are the most affected in terms of the money they invest in controlling ticks.
Collapse
Affiliation(s)
- Valeria Paucar-Quishpe
- Instituto de Investigación en Zoonosis (CIZ), Universidad Central del Ecuador, Quito, Ecuador
- Research Unit of Epidemiology and Risk Analysis applied to Veterinary Science (UREAR-ULg)/Fundamental and Applied Research for Animals & Health (FARAH) Center/Faculty of Veterinary Medicine, University of Liege, Liège, Belgium
| | - Ximena Pérez-Otáñez
- Instituto de Investigación en Zoonosis (CIZ), Universidad Central del Ecuador, Quito, Ecuador
- Georges Lemaitre Centre for Earth and Climate Research, Earth & Life Institute, UCLouvain, Louvain-la-Neuve, Belgium
| | - Richar Rodríguez-Hidalgo
- Instituto de Investigación en Zoonosis (CIZ), Universidad Central del Ecuador, Quito, Ecuador
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| | | | - Cecilia Pérez-Escalante
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| | - Jorge Grijalva-Olmedo
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| | - Sandra Enríquez
- Instituto de Investigación en Zoonosis (CIZ), Universidad Central del Ecuador, Quito, Ecuador
| | | | - Luis Sandoval-Trávez
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| | | | - Sophie O. Vanwambeke
- Georges Lemaitre Centre for Earth and Climate Research, Earth & Life Institute, UCLouvain, Louvain-la-Neuve, Belgium
| | - Claude Saegerman
- Research Unit of Epidemiology and Risk Analysis applied to Veterinary Science (UREAR-ULg)/Fundamental and Applied Research for Animals & Health (FARAH) Center/Faculty of Veterinary Medicine, University of Liege, Liège, Belgium
| | - Lenin Ron-Garrido
- Instituto de Investigación en Zoonosis (CIZ), Universidad Central del Ecuador, Quito, Ecuador
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| |
Collapse
|
8
|
García-Ponce R, Hernández-Escareño JJ, Cruz-Valdez JC, Galindo-Rodríguez SA, Heya MS, Villarreal-Villarreal JP. Ixodicidal effect of extracts from Cordia boissieri, Artemisia ludoviciana and Litchi chinensis on Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). BRAZ J BIOL 2023; 84:e264425. [PMID: 36722676 DOI: 10.1590/1519-6984.264425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 12/14/2022] [Indexed: 02/02/2023] Open
Abstract
The ixodicidal activity of the methanolic extracts of Artemisia ludoviciana (Astereceae), Cordia boissieri (Boraginaceae) and Litchi chinensis (Sapindaceae) against two field populations of Rhipicephalus (Boophilus) microplus from the state of Nuevo Leon (NL) and Veracruz (VER) was evaluated. The extract of L. chinensis in the concentration of 150 mg/ml showed efficacies of 100% and 99% against engorged females and mortalities of 98% and 99% against larvae. C. boissieri in the same concentration showed efficacies of 71% and 37% against engorged adults and mortalities of 33.04% and 10.33% against larvae and A. ludoviciana had efficacies of 94% and 83% in adults and mortalities of 89.39% and 89.21% against larvae in both populations respectively. The enzymatic activity of Acetylcholinesterase (AChE), Carboxylesterase (CaE), Glutathione-S-Transferase (GST) and Alkaline Phosphatase (ALP) was measured in both populations of ticks. As a result, a significant difference between both populations was shown, being the VER population the one that exhibited a higher enzymatic activity (p ≤ 0.05). It can be concluded that the methanolic extract of the seed of L. chinensis shows potential ixodicidal activity and can be used as an alternative source of tick control, however, prior characterization, toxicity and formulation studies are necessary.
Collapse
Affiliation(s)
- R García-Ponce
- Universidad Autónoma de Nuevo León - UANL, School of Veterinary Medicine and Zootechnics, Department of Microbiology and Parasitology, Laboratory of Microbiology and Parasitology, Cd. General Escobedo, Nuevo León, México
| | - J J Hernández-Escareño
- Universidad Autónoma de Nuevo León - UANL, School of Veterinary Medicine and Zootechnics, Department of Microbiology and Parasitology, Laboratory of Microbiology and Parasitology, Cd. General Escobedo, Nuevo León, México
| | - J C Cruz-Valdez
- Universidad Autónoma de Nuevo León - UANL, School of Veterinary Medicine and Zootechnics, Department of Microbiology and Parasitology, Laboratory of Microbiology and Parasitology, Cd. General Escobedo, Nuevo León, México
| | - S A Galindo-Rodríguez
- Universidad Autónoma of Nuevo León-UANL, School of Biological Sciences, Department of Chemistry, Laboratory of Analytical Chemistry, San Nicolás de los Garza, Nuevo León, México
| | - M S Heya
- Universidad Autónoma of Nuevo León-UANL, School of Biological Sciences, Department of Chemistry, Laboratory of Analytical Chemistry, San Nicolás de los Garza, Nuevo León, México
| | - J P Villarreal-Villarreal
- Universidad Autónoma de Nuevo León - UANL, School of Veterinary Medicine and Zootechnics, Department of Microbiology and Parasitology, Laboratory of Microbiology and Parasitology, Cd. General Escobedo, Nuevo León, México
| |
Collapse
|
9
|
Ruiling Z, Wenjuan L, Kexin Z, Xuejun W, Zhong Z. Developmental transcriptomics throughout the embryonic developmental process of Rhipicephalus turanicus reveals stage-specific gene expression profiles. Parasit Vectors 2022; 15:89. [PMID: 35292089 PMCID: PMC8922761 DOI: 10.1186/s13071-022-05214-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/20/2022] [Indexed: 11/10/2022] Open
Abstract
Background Ticks are important vectors and transmit diverse pathogens, including protozoa, viruses, and bacteria. Tick-borne diseases can cause damage to both human health and the livestock industries. The control and prevention of ticks and tick-borne diseases has relied heavily on acaricides. Methods In the present study, using a high-throughput RNA sequencing (RNA-Seq) technique, we performed a comprehensive time-series transcriptomic analysis throughout the embryogenesis period of Rhipicephalus turanicus. Results Altogether, 127,157 unigenes were assembled and clustered. Gene expression differences among the embryonic stages demonstrated that the most differentially expressed genes (DEGs) were observed in the comparisons of early embryonic stages (RTE5 vs. RTE10, 9726 genes), and there were far fewer DEGs in later stages (RTE25 vs. RTE30, 2751 genes). Furthermore, 16 distinct gene modules were identified according to weighted gene co-expression network analysis (WGCNA), and genes in different modules displayed stage-specific characteristics. Gene Ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment suggested that some genes involved in organ and tissue formation were significantly upregulated in the early embryonic developmental stages, whereas metabolism-related pathways were more enriched in the later embryonic developmental stages. Conclusions These transcriptome studies revealed gene expression profiles at different stages of embryonic development, which would be useful for interrupting the embryonic development of ticks and disrupting the transmission of tick-borne diseases. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05214-w.
Collapse
Affiliation(s)
- Zhang Ruiling
- Collaborative Innovation Center for the Origin and Control of Emerging Infectious Diseases, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China. .,School of Basic Medical Sciences, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China.
| | - Liu Wenjuan
- Collaborative Innovation Center for the Origin and Control of Emerging Infectious Diseases, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China.,School of Basic Medical Sciences, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China
| | - Zhang Kexin
- Collaborative Innovation Center for the Origin and Control of Emerging Infectious Diseases, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China.,School of Basic Medical Sciences, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China
| | - Wang Xuejun
- Collaborative Innovation Center for the Origin and Control of Emerging Infectious Diseases, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China. .,Shandong Provincial Center for Disease Control and Prevention, Jinan, China.
| | - Zhang Zhong
- Collaborative Innovation Center for the Origin and Control of Emerging Infectious Diseases, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China. .,School of Basic Medical Sciences, Shandong First Medical University (Shandong Academy of Medical Sciences), Tai'an, China.
| |
Collapse
|
10
|
Dzemo WD, Thekisoe O, Vudriko P. Development of acaricide resistance in tick populations of cattle: A systematic review and meta-analysis. Heliyon 2022; 8:e08718. [PMID: 35059516 PMCID: PMC8760414 DOI: 10.1016/j.heliyon.2022.e08718] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/25/2021] [Accepted: 01/04/2022] [Indexed: 12/27/2022] Open
Abstract
The development of acaricide resistance in ticks infesting cattle is a major problem in the livestock industry in tropical and subtropical regions worldwide. To determine the current global trends and prevalence of acaricide resistance development (ARD) in tick populations of cattle, a systematic review and meta-analysis with an emphasis on Rhipicephalus (Boophilus) microplus was conducted. Data searches from five English electronic databases yielded 88 journal articles published between 1992 and 2020. In total, 218 in - vitro bioassays were used to investigate 3939 tick populations of cattle; of these, the 57.6% that exhibited ARD were largely limited to South America (Brazil), Central America (Mexico), and Asia (India). A total of 3391 of these tick populations were R. (B.) microplus, of which 2013 exhibited ARD. Random effects meta-analyses indicated that the exhibition of ARD was higher in R. (B.) microplus (66.2%) than in other tick species. Global prevalence estimates of ARD in R. (B.) microplus vary as a function of geography, detection methods, and acaricide compounds. In general, high heterogeneity was noted among the studies. However, homogeneity was observed among studies from India, suggesting the establishment of acaricide resistance in Indian R. (B.) microplus populations. Current tick control interventions are urgently required to limit the evolution and implications of resistance development.
Collapse
Affiliation(s)
- William Diymba Dzemo
- Department of Biological and Environmental Sciences, Faculty of Natural Sciences, Walter Sisulu University, Private Bag X1, Mthatha 5117, South Africa.,Unit for Environmental Sciences and Management, North West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa
| | - Oriel Thekisoe
- Unit for Environmental Sciences and Management, North West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa
| | - Patrick Vudriko
- Research Center for Tropical Diseases and Vector Control, Department of Veterinary Pharmacy, Clinics and Comparative Medicine, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O Box 7062, Kampala, Uganda
| |
Collapse
|
11
|
Rodriguez-Vivas RI, España ER, Blanco IL, Ojeda-Chi MM, Trinidad-Martinez I, Islas JAT, Bhushan C. Monitoring the resistance of Rhipicephalus microplus to amitraz, flumethrin, coumaphos, and ivermectin on cattle farms in Mexico. Vet Parasitol Reg Stud Reports 2021; 26:100644. [PMID: 34879955 DOI: 10.1016/j.vprsr.2021.100644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 09/06/2021] [Accepted: 09/17/2021] [Indexed: 11/24/2022]
Abstract
The prevalence, resistance ratios and factor associated with Rhipicephalu microplus populations resistant to amitraz, flumethrin, coumaphos, and ivermectina (IVM) in Mexico were studied. Field tick populations were collected from 54 farms in 15 different states of Mexico. The dose-response bioassays were carried out using the larval immersion test (amitraz and IVM) and the modified larval packet test (flumethrin and coumaphos) against R. microplus. Mortality data were subjected to probit analysis to calculate lethal concentrations at 50%. A logistic regression model was used to evaluate the relation between resistance and possible associated factors. The phenotype was defined as high resistant (HR), low resistant (LR) or susceptible (S). The overall prevalence of cattle farms with R. microplus resistant to coumaphos, amitraz, flumethrin and IVM were 25.9, 46.2, 31.5 and 68.5%, respectively. For coumaphos, 74.1, 22.2, and 3.7% were classified as S, LR, and HR, respectively, whereas, for amitraz, 53.7, 24.1, and 22.2% of phenotypes were S, LR, and HR, respectively, for flumethrin 68.5, 14.8, and 16.7% were S, LR and HR respectively, and for IVM, 31.5, 46.3, and 22.2% were S, LR, and HR, respectively. We identified that cattle farms without acaricide rotation program (OR: 7.66, CL95%: 1.70-34.47, P: 0.008) had a higher probability of developing R. microplus resistant to amitraz. We concluded that amitraz and IVM resistance in R. microplus is frequent, but mainly at a low level in cattle farms of Mexico. Cattle farms without acaricide rotation program had higher probability of developing R. microplus resistant to amitraz.
Collapse
Affiliation(s)
- Roger I Rodriguez-Vivas
- Facultad de Medicina Veterinaria y Zootecnia, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, km. 15.5 Carretera Mérida-Xmatkuil, Código 97000, Mérida, Mexico.
| | - Eduardo Ramirez España
- Elanco Salud Animal SA de CV, Boulevard Puerta de Hierro 5153, piso 18, Col. Puerta de Hierro CP, 45116 Zapopan, Jalisco, Mexico
| | - Ivan Lozano Blanco
- Elanco Salud Animal SA de CV, Boulevard Puerta de Hierro 5153, piso 18, Col. Puerta de Hierro CP, 45116 Zapopan, Jalisco, Mexico
| | - Melina M Ojeda-Chi
- Facultad de Medicina Veterinaria y Zootecnia, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, km. 15.5 Carretera Mérida-Xmatkuil, Código 97000, Mérida, Mexico
| | - Iris Trinidad-Martinez
- Facultad de Medicina Veterinaria y Zootecnia, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, km. 15.5 Carretera Mérida-Xmatkuil, Código 97000, Mérida, Mexico
| | - Juan Agustin Torres Islas
- Elanco Salud Animal SA de CV, Boulevard Puerta de Hierro 5153, piso 18, Col. Puerta de Hierro CP, 45116 Zapopan, Jalisco, Mexico
| | - Chandra Bhushan
- Elanco Animal Health, Alfred-Nobel Str. 50, 40789 Monheim, Germany
| |
Collapse
|
12
|
Synthesis, LC-MS/MS analysis, and biological evaluation of two vaccine candidates against ticks based on the antigenic P0 peptide from R. sanguineus linked to the p64K carrier protein from Neisseria meningitidis. Anal Bioanal Chem 2021; 413:5885-5900. [PMID: 34341841 PMCID: PMC8328535 DOI: 10.1007/s00216-021-03569-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 07/12/2021] [Accepted: 07/20/2021] [Indexed: 11/24/2022]
Abstract
A peptide from the P0 acidic ribosomal protein (pP0) of ticks conjugated to keyhole limpet hemocyanin from Megathura crenulata has shown to be effective against different tick species when used in host vaccination. Turning this peptide into a commercial anti-tick vaccine will depend on finding the appropriate, technically and economically feasible way to present it to the host immune system. Two conjugates (p64K-Cys1pP0 and p64K-βAla1pP0) were synthesized using the p64K carrier protein from Neisseria meningitidis produced in Escherichia coli, the same cross-linking reagent, and two analogues of pP0. The SDS-PAGE analysis of p64K-Cys1pP0 showed a heterogeneous conjugate compared to p64K-βAla1pP0 that was detected as a protein band at 91kDa. The pP0/p64K ratio determined by MALDI-MS for p64K-Cys1pP0 ranged from 1 to 8, being 3-5 the predominant ratio, while in the case of p64K-βAla1pP0 this ratio was 5-7. Cys1pP0 was partially linked to 35 out of 39 Lys residues and the N-terminal end, while βAla1pP0 was mostly linked to the six free cysteine residues, to the N-terminal end, and, in a lesser extent, to Lys residues. The assignment of the conjugation sites and side reactions were based on the identification of type 2 peptides. Rabbit immunizations showed the best anti-pP0 titers and the highest efficacy against Rhipicephalus sanguineus ticks when the p64K-Cys1pP0 was used as vaccine antigen. The presence of high molecular mass aggregates observed in the SDS-PAGE analysis of p64K-Cys1pP0 could be responsible for a better immune response against pP0 and consequently for its better efficacy as an anti-tick vaccine. Graphical abstract ![]()
Collapse
|
13
|
Monteiro C, Lage TCDA, Marchesini P, Vale L, Perinotto WMDS, Lopes WDZ, Fernandes SA, Bittencourt VREP, Furlong J, Prata MCDA. Combination of entomopathogenic nematodes with acaricides or essential oil of Lippia triplinervis against Rhipicephalus microplus (Acari: Ixodidae). VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2021; 23:100526. [PMID: 33678380 DOI: 10.1016/j.vprsr.2020.100526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 11/18/2022]
Abstract
This study aimed to evaluate the combination effect of Heterorhabditis bacteriophora HP88 and H. indica LPP1, with the acaricides deltamethrin, amitraz and chlorfenvinphos, and the essential oil (EO) of Lippia triplinervis, against engorged females of Rhipicephalus microplus. In order to verify the effect of acaricides and EO, the adult immersion test was used, and in the groups treated only with entomopathogenic nematodes (EPNs), 150 infective juveniles were used per female. In the treatments with nematodes in combination with the acaricides or EO, the females were immersed in the solutions (acaricide or EO) and then transferred to Petri dishes for application of the nematodes. The treatment with acaricides resulted in a control percentage lower than 70%, except in the group treated with chlorfenvinphos in the second experiment (84.3%). The control percentage was 73% for L. triplinervis EO, and greater than 90% in all the groups treated with nematodes. For treatments with EPNs combined with the acaricides or EO, the efficacy was greater than 95% (except for deltamethrin + HP88), and reached 100% in the treatment with LPP1 + amitraz. It can be concluded that the EPNs at the concentrations tested were compatible with the acaricides deltamethrin, amitraz and chlorfenvinphos, and with the EO of L. triplinervis. These combinations enhance the effect of these control agents.
Collapse
Affiliation(s)
- Caio Monteiro
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Rua 235, s/n, Setor Universitário, Goiânia, Goiás CEP: 74605-050, Brazil; Programa de Pós-graduação em Ciências Animal, Universidade Federal de Goiás, Avenida Esperança, s/n, Campus Samambaia, Goiânia, Goiás CEP: 74.690-900, Brazil
| | - Tiago Coelho de Assis Lage
- Grupo de Química Supramolecular e Biomimética (GQSB), Departamento de Química, Universidade Federal de Viçosa (UFV), Campus Universitário, Avenida P.H. Rolfs, s/n, Viçosa, Minas Gerais CEP: 36570-900, Brazil
| | - Paula Marchesini
- Programa de Pós-graduação em Ciências Veterinárias, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Rodovia BR 465, Seropédica, Rio de Janeiro CEP: 23890-000, Brazil
| | - Letícia Vale
- Programa de Pós-graduação em Ciências Animal, Universidade Federal de Goiás, Avenida Esperança, s/n, Campus Samambaia, Goiânia, Goiás CEP: 74.690-900, Brazil
| | - Wendell Marcelo de Souza Perinotto
- Centro de Ciências Agrárias, Ambientais e Biológica, Universidade Federal do Recôncavo da Bahia, Rua Rui Barbosa, 710, Cruz das Almas, Bahia CEP: 44380-000, Brazil.
| | - Welber Daniel Zanetti Lopes
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Rua 235, s/n, Setor Universitário, Goiânia, Goiás CEP: 74605-050, Brazil; Programa de Pós-graduação em Ciências Animal, Universidade Federal de Goiás, Avenida Esperança, s/n, Campus Samambaia, Goiânia, Goiás CEP: 74.690-900, Brazil
| | - Sergio Antônio Fernandes
- Grupo de Química Supramolecular e Biomimética (GQSB), Departamento de Química, Universidade Federal de Viçosa (UFV), Campus Universitário, Avenida P.H. Rolfs, s/n, Viçosa, Minas Gerais CEP: 36570-900, Brazil
| | - Vânia Rita Elias Pinheiro Bittencourt
- Programa de Pós-graduação em Ciências Veterinárias, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Rodovia BR 465, Seropédica, Rio de Janeiro CEP: 23890-000, Brazil
| | - John Furlong
- Laboratório de Parasitologia da Embrapa Gado de Leite (Embrapa CNPGL), Rua Eugênio do Nascimento, 610, Bairro Dom Bosco, Juiz de Fora, Minas Gerais CEP: 36038-330, Brazil
| | - Márcia Cristina de Azevedo Prata
- Laboratório de Parasitologia da Embrapa Gado de Leite (Embrapa CNPGL), Rua Eugênio do Nascimento, 610, Bairro Dom Bosco, Juiz de Fora, Minas Gerais CEP: 36038-330, Brazil
| |
Collapse
|
14
|
Agwunobi DO, Yu Z, Liu J. A retrospective review on ixodid tick resistance against synthetic acaricides: implications and perspectives for future resistance prevention and mitigation. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 173:104776. [PMID: 33771255 DOI: 10.1016/j.pestbp.2021.104776] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/19/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
The ending of the nineteenth-century was characterized by an escalation of ticks and tick-borne diseases that resulted in the death of many cattle. This necessitated the search for an effective means of tick control. Arsenicals were introduced in Australia in 1895, and arsenic-based dipping vats went on to be used for about 40 years until resistance was found in ticks and more effective alternatives - chemical acaricides - were developed after World War II. However, the development of resistance by ticks, environmental persistence, and mammalian toxicity militated against the sustained use of subsequent chemical acaricides. Furthermore, the development of resistance is a phenomenon that would always evolve, and the multiple mechanisms underlying the synthetic acaricides resistance are of great importance for future integrated control of ticks and tick-borne diseases. Hence, this study retrospectively reviewed the development of synthetic acaricides and the underlying mechanisms of tick resistance against synthetic acaricides in the hope of providing the implications and perspectives for resistance prevention and mitigation for future tick control.
Collapse
Affiliation(s)
- Desmond O Agwunobi
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Zhijun Yu
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
| | - Jingze Liu
- Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
| |
Collapse
|
15
|
Reis AC, Konig IFM, Rezende DADCS, Gonçalves RRP, Lunguinho ADS, Ribeiro JCS, Cardoso MDG, Remedio RN. Cytotoxic effects of Satureja montana L. essential oil on oocytes of engorged Rhipicephalus microplus female ticks (Acari: Ixodidae). Microsc Res Tech 2021; 84:1375-1388. [PMID: 33405270 DOI: 10.1002/jemt.23693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/16/2020] [Accepted: 12/21/2020] [Indexed: 11/09/2022]
Abstract
In addition to pesticidal activity, the capacity of natural compounds to inhibit the reproduction of parasites emerge as an important alternative tick control method. In this context, Satureja spp. stand out due to their recognized pesticidal properties. Among parasites of veterinary importance, the cattle tick, Rhipicephalus microplus, is responsible for great economic losses in livestock and transmission of relevant pathogens. Thus, the aim of this study was to evaluate the effects of different concentrations of the essential oil of Satureja montana L. on the ovary morphology of R. microplus engorged females through histological and histochemical techniques. The most remarkable morphological changes found were: cytoplasmic vacuolation of germ cells, irregular and thicker chorion, irregular oocyte shape, ring-shaped nucleolus, decrease in protein and carbohydrate content in oocytes, in addition to cellular changes in the oviduct and pedicel. All morphological changes were assessed using a semiquantitative method already established in the literature. Ticks exposed to 5.0 μl/ml of essential oil showed the most significant changes when compared to control groups. Thus, the essential oil of S. montana L. damaged the reproductive system of R. microplus, which may impair ticks' offspring production and promote a long-term control of this species. HIGHLIGHTS: The essential oil of Satureja montana L. affects the ovary morphology of the cattle tick. The main morphological alterations found were cytoplasmic vacuolation, irregular and thicker chorion and irregular oocyte shape. These alterations may impair the development of eggs.
Collapse
Affiliation(s)
- Aline Chaves Reis
- Department of Health Sciences, Federal University of Lavras (UFLA), Lavras, Minas Gerais, Brazil
| | | | | | | | | | | | | | - Rafael Neodini Remedio
- Department of Health Sciences, Federal University of Lavras (UFLA), Lavras, Minas Gerais, Brazil
| |
Collapse
|
16
|
Esteve-Gasent MD, Rodríguez-Vivas RI, Medina RF, Ellis D, Schwartz A, Cortés Garcia B, Hunt C, Tietjen M, Bonilla D, Thomas D, Logan LL, Hasel H, Alvarez Martínez JA, Hernández-Escareño JJ, Mosqueda Gualito J, Alonso Díaz MA, Rosario-Cruz R, Soberanes Céspedes N, Merino Charrez O, Howard T, Chávez Niño VM, Pérez de León AA. Research on Integrated Management for Cattle Fever Ticks and Bovine Babesiosis in the United States and Mexico: Current Status and Opportunities for Binational Coordination. Pathogens 2020; 9:pathogens9110871. [PMID: 33114005 PMCID: PMC7690670 DOI: 10.3390/pathogens9110871] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 12/23/2022] Open
Abstract
Bovine babesiosis is a reportable transboundary animal disease caused by Babesia bovis and Babesiabigemina in the Americas where these apicomplexan protozoa are transmitted by the invasive cattle fever ticks Rhipicephalus (Boophilus) microplus and Rhipicephalus(Boophilus) annulatus. In countries like Mexico where cattle fever ticks remain endemic, bovine babesiosis is detrimental to cattle health and results in a significant economic cost to the livestock industry. These cattle disease vectors continue to threaten the U.S. cattle industry despite their elimination through efforts of the Cattle Fever Tick Eradication Program. Mexico and the U.S. share a common interest in managing cattle fever ticks through their economically important binational cattle trade. Here, we report the outcomes of a meeting where stakeholders from Mexico and the U.S. representing the livestock and pharmaceutical industry, regulatory agencies, and research institutions gathered to discuss research and knowledge gaps requiring attention to advance progressive management strategies for bovine babesiosis and cattle fever ticks. Research recommendations and other actionable activities reflect commitment among meeting participants to seize opportunities for collaborative efforts. Addressing these research gaps is expected to yield scientific knowledge benefitting the interdependent livestock industries of Mexico and the U.S. through its translation into enhanced biosecurity against the economic and animal health impacts of bovine babesiosis and cattle fever ticks.
Collapse
Affiliation(s)
- Maria D. Esteve-Gasent
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA;
| | - Roger I. Rodríguez-Vivas
- Campus de Ciencias Biológicas y Agropecuarias, FMVZ, Universidad Autónoma de Yucatán, km. 15.5 Carretera Mérida-Xmatkuil, Mérida, Yucatán 97000, Mexico
- Correspondence:
| | - Raúl F. Medina
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA;
| | - Dee Ellis
- Institute for Infectious Animal Diseases, Texas A&M AgriLife Research, College Station, TX 77843, USA; (D.E.); (C.H.)
| | - Andy Schwartz
- Texas Animal Health Commission, Austin, TX 78758, USA;
| | - Baltazar Cortés Garcia
- Departamento de Rabia Paralítica y Garrapata, Dirección de Campañas Zoosanitarias, Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA), Avenida Insurgentes Sur N° 489 Piso 9, Colonia Hipódromo, Alcaldía Cuauhtémoc, Ciudad de Mexico 06100, Mexico;
| | - Carrie Hunt
- Institute for Infectious Animal Diseases, Texas A&M AgriLife Research, College Station, TX 77843, USA; (D.E.); (C.H.)
| | - Mackenzie Tietjen
- United States Department of Agriculture, Agricultural Research Service (USDA–ARS), Knipling–Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, Kerrville, TX 78028, USA; (M.T.); (A.A.P.d.L.)
| | - Denise Bonilla
- Veterinary Services, Animal and Plant Health Inspection Service International Services, United States Department of Agriculture (USDA-APHIS), Fort Collins, CO 80526, USA;
| | - Don Thomas
- United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Cattel Fever Tick Research Laboratory, Moore Air Base, Edinburg, TX 78541, USA;
| | - Linda L. Logan
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA;
| | - Hallie Hasel
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, (USDA-APHIS-VS), Austin, TX 78701, USA;
| | - Jesús A. Alvarez Martínez
- CENID-SAI, Instituto Nacional de Investigaciones Forestales Agricolas y Pecuarias, Carr. Fed. Cuernavaca-Cuautla No. 8534, Col. Progreso. Jiutepec, Morelos 62390, Mexico;
| | - Jesús J. Hernández-Escareño
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Nuevo León, General Francisco Villa S/N, Hacienda del Canada, Ciudad General Escobedo, Nuevo León 66054, Mexico;
| | - Juan Mosqueda Gualito
- Immunology and Vaccines Laboratory, C. A. Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro Queretaro 76140, Mexico;
| | - Miguel A. Alonso Díaz
- Centro de Enseñanza, Investigación y Extensión en Ganadería Tropical, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Km. 5.5 Carretera Federal Tlapacoyan-Martínez de la Torre, Martínez de la Torre, Veracruz 93600, Mexico;
| | - Rodrigo Rosario-Cruz
- BioSA Research Lab., Natural Sciences College, Campus el ‘Shalako’ Las Petaquillas, Autonomous Guerrero State University, Chilpancingo, Guerrero 62105, Mexico;
| | - Noé Soberanes Céspedes
- Lapisa S.A. de C.V. Carretera La Piedad-Guadalajara Km 5.5, Col. Camelinas, La Piedad, Michoacán 59375, Mexico;
| | - Octavio Merino Charrez
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Tamaulipas, Km. 5 Carretera Victoria-Mante, Ciudad Victoria, Tamaulipas 87000, Mexico;
| | - Tami Howard
- United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, (USDA-APHIS-VS), Field Operations, Southern Border Ports, Albuquerque, NM 87109, USA;
| | - Victoria M. Chávez Niño
- United States Department of Agriculture, Animal and Plant Health Inspection Service, International Services, (USDA-APHIS-IS), Mexico, Sierra Nevada 115, Col. Lomas de Chapultepec, Mexico City 11000, Mexico;
| | - Adalberto A. Pérez de León
- United States Department of Agriculture, Agricultural Research Service (USDA–ARS), Knipling–Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, Kerrville, TX 78028, USA; (M.T.); (A.A.P.d.L.)
| |
Collapse
|
17
|
Jyoti, Singh NK, Singh H, Singh NK, Rath SS. Genotyping amitraz resistance profiles in Rhipicephalus microplus Canestrini (Acari: Ixodidae) ticks from Punjab, India. Ticks Tick Borne Dis 2020; 12:101578. [PMID: 33074150 DOI: 10.1016/j.ttbdis.2020.101578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/29/2020] [Accepted: 09/11/2020] [Indexed: 01/01/2023]
Abstract
Acaricide resistance is one of the greatest threats to sustainable and effective control of vector ticks worldwide. The amitraz resistance status in cattle tick, Rhipicephalus microplus populations collected from 18 districts of Punjab in north-western India were characterized using bioassay and molecular assays. The modified larval packet test was used and the resistance factors (RF) against amitraz for the field populations were in the range of 0.36-4.85, indicating level I resistance status in ten populations. Characterization of a partial segment of the octopamine/tyramine (OCT/Tyr) receptor gene of R. microplus field populations from Punjab revealed a total of 18 nucleotide substitutions in the coding region out of which 5 were non-synonymous substitutions. Three of these non-synonymous substitutions (T8P, V15I and A20 T) were earlier reported in American and South African populations of R. microplus. Among the two single nucleotide polymorphisms (A22C-T8P; T65C-L22S) potentially linked to amitraz resistance in American, South African and Zimbabwean resistant populations, only the T8P substitution was recorded from the Barnala population. The PCR-RFLP assay using EciI restriction enzyme was used for genotyping of the larvae as homozygous resistant (RR), homozygous susceptible (SS) and heterozygous (SR). Genotyping of 514 larval DNA samples from 18 field populations revealed 92.8 % larval population as SR and the remaining 7.2 % as RR genotypes. The percentage of resistant alleles in the tick populations was 53.6 (range 50.0-57.2) indicating its moderate distribution in the region. The present study is the pioneer report establishing the hypothesis that amitraz-resistance is recessively inherited and heterozygous individuals show phenotypic susceptibility to the drug in the Indian tick populations.
Collapse
Affiliation(s)
- Jyoti
- Department of Veterinary Parasitology, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, 141004, India
| | - Nirbhay Kumar Singh
- Department of Veterinary Parasitology, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, 141004, India.
| | - Harkirat Singh
- Department of Veterinary Parasitology, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, 141004, India
| | - Niraj Kumar Singh
- College of Animal Biotechnology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, 141004, India
| | - Shitanshu S Rath
- Department of Veterinary Parasitology, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, 141004, India
| |
Collapse
|
18
|
Use of Metarhizum aniopliae s.l. to control soil-dwelling longhorned tick, Haemaphysalis longicornis. J Invertebr Pathol 2019; 166:107230. [PMID: 31419401 DOI: 10.1016/j.jip.2019.107230] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/06/2019] [Accepted: 08/10/2019] [Indexed: 11/24/2022]
Abstract
The longhorned tick (bush tick),Haemaphysalis longicornis (Ixodida: Ixodidae), is a serious pest; it transmits the severe fever with thrombocytopenia syndrome (SFTS) virus to humans and has a wide distribution. The use of chemical control is not favored for environmental and health reasons, so more environmentally sound management methods need to be developed. Herein, we describe the use of an entomopathogenic fungal library to develop a fungus-mediated tick management system. Field-collected nymphs were assayed for their susceptibility to entomopathogenic fungi belonging to genera Beauveria, Metarhizium, Cordyceps, and Akanthomyces. Three M. anisopliae s.l. isolates, JEF-214, -279, and -290 showed high virulence in a dose-dependent manner. One Cordyceps isolate was pathogenic but virulence was much lower than the M. anisopliae isolates. Beauveria isolates were not pathogenic to the tick. Because the longhorned tick dwells on the soil surface except for blood-feeding periods, the soil surface was sprayed with conidial suspensions of the isolates after the release of longhorned ticks. The treatments resulted in 60-90% mortality after 30 days. M. anisopliae s.l. isolates were highly virulent against longhorned tick, and the application of fungus-based biopesticides on the soil surface could be an effective control strategy to reduce the tick population for long-term tick management.
Collapse
|
19
|
Waltero C, de Abreu LA, Alonso T, Nunes-da-Fonseca R, da Silva Vaz I, Logullo C. TOR as a Regulatory Target in Rhipicephalus microplus Embryogenesis. Front Physiol 2019; 10:965. [PMID: 31417424 PMCID: PMC6684781 DOI: 10.3389/fphys.2019.00965] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/11/2019] [Indexed: 12/11/2022] Open
Abstract
Embryogenesis is a metabolically intensive process carried out under tightly controlled conditions. The insulin signaling pathway regulates glucose homeostasis and is essential for reproduction in metazoan model species. Three key targets are part of this signaling pathway: protein kinase B (PKB, or AKT), glycogen synthase kinase 3 (GSK-3), and target of rapamycin (TOR). While the role of AKT and GSK-3 has been investigated during tick embryonic development, the role of TOR remains unknown. In this study, TOR and two other downstream effectors, namely S6 kinase (S6K) and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), were investigated in in vitro studies using the tick embryonic cell line BME26. First, we show that exogenous insulin can stimulate TOR transcription. Second, TOR chemical inhibition led to a decrease in BME26 cell viability, loss of membrane integrity, and downregulation of S6K and 4E-BP1 transcription. Conversely, treating BME26 cells with chemical inhibitors of AKT or GSK-3 did not affect S6K and 4E-BP1 transcription, showing that TOR is specifically required to activate its downstream targets. To address the role of TOR in tick reproduction, in vivo studies were performed. Analysis of relative transcription during different stages of tick embryonic development showed different levels of transcription for TOR, and a maternal deposition of S6K and 4E-BP1 transcripts. Injection of TOR double-stranded RNA (dsRNA) into partially fed females led to a slight delay in oviposition, an atypical egg external morphology, decreased vitellin content in eggs, and decreased larval hatching. Taken together, our data show that the TOR signaling pathway is important for tick reproduction, that TOR acts as a regulatory target in Rhipicephalus microplus embryogenesis and represents a promising target for the development of compounds for tick control.
Collapse
Affiliation(s)
- Camila Waltero
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Ciências Morfofuncionais, Instituto de Biodiversidade e Sustentabilidade NUPEM, Universidade Federal do Rio de Janeiro, Macaé, Brazil
| | - Leonardo Araujo de Abreu
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Ciências Morfofuncionais, Instituto de Biodiversidade e Sustentabilidade NUPEM, Universidade Federal do Rio de Janeiro, Macaé, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| | - Thayná Alonso
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Ciências Morfofuncionais, Instituto de Biodiversidade e Sustentabilidade NUPEM, Universidade Federal do Rio de Janeiro, Macaé, Brazil
| | - Rodrigo Nunes-da-Fonseca
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Ciências Morfofuncionais, Instituto de Biodiversidade e Sustentabilidade NUPEM, Universidade Federal do Rio de Janeiro, Macaé, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| | - Itabajara da Silva Vaz
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
- Centro de Biotecnologia, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlos Logullo
- Laboratório Integrado de Bioquímica Hatisaburo Masuda and Laboratório Integrado de Ciências Morfofuncionais, Instituto de Biodiversidade e Sustentabilidade NUPEM, Universidade Federal do Rio de Janeiro, Macaé, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| |
Collapse
|
20
|
Kumar R. Molecular markers and their application in the monitoring of acaricide resistance in Rhipicephalus microplus. EXPERIMENTAL & APPLIED ACAROLOGY 2019; 78:149-172. [PMID: 31190248 DOI: 10.1007/s10493-019-00394-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 06/03/2019] [Indexed: 06/09/2023]
Abstract
Monitoring acaricide resistance and understanding the underlying mechanisms are critically important in developing strategies for resistance management and tick control. Identification of single nucleotide polymorphisms in the acaricide-resistant associated gene of Rhipicephalus microplus has enabled the development of molecular markers for detection and monitoring of resistance against different types of acaricide. There are many molecular markers developed for resistance monitoring, including mutations on target genes such as sodium channel, acetylcholinesterase, carboxylesterase, β-adrenergic octopamine receptor, octopamine-tyramine etc. Molecular genotyping through molecular markers can detect the presence of resistance-associated genes in a tick population before it reaches high frequency. This review aims to provide an update on the various molecular markers discovered to date from different regions of the world.
Collapse
Affiliation(s)
- Rinesh Kumar
- College of Veterinary Science and Animal Husbandry, Rewa, Madhya Pradesh, India.
| |
Collapse
|
21
|
Toaleb NI, Gabr HSM, Abd El-Shafy S, Abdel-Rahman EH. Evaluation of vaccine candidates purified from the adult ticks of Ornithodoros savignyi (Acari: Argasidae) and Hyalomma dromedarii (Acari: Ixodidae) against tick infestations. J Parasit Dis 2019; 43:246-255. [PMID: 31263330 PMCID: PMC6570741 DOI: 10.1007/s12639-018-01082-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 12/31/2018] [Indexed: 12/15/2022] Open
Abstract
Ticks cause anemia, toxicosis, growth delay, and transmit infectious diseases in animals and humans. The current study aimed to evaluate the immunoprophylactic properties of two vaccine candidates to develop vaccine against tick infestations. These two vaccine candidates were specific fraction from the adults of the soft tick Ornithodoros savignyi and cross-reactive fraction from the adults of the hard tick Hyalomma dromedarii. Both specific and cross-reactive fractions were isolated by Cyanogen Bromide-activated Sepharose-4B affinity column chromatography. Both candidates proved their cross-reactivity by enzyme linked immunosorbent assay and Western blot. Characterization of the two vaccines by SDS-PAGE showed that the O. savignyi specific fraction consists of four bands; 97, 85, 66 and 11.5 kDa compared with nine bands associated with its crude antigen (196-11.5 kDa). The H. dromedarii cross-reactive vaccine candidate consists of three bands; 97, 66 and 45 kDa compared to eight bands of its crude antigen (196-21 kDa). Two common bands of 97 and 66 kDa between two candidates showed immunogenic cross-reactivity with the developed antisera of both infestations by Western blot. Immunization of rabbits intramuscularly with two doses of the fractions separately (40 µg/kg) led to immunological and parasitological changes. Immunologically; the level of immunoglobulins in vaccinated rabbits increased significantly compared with control infested non-vaccinated rabbits. These immunoglobulins are probably responsible for the protective effect of both candidates. Parasitologically, immunized rabbits showed protection against infestation by adult ticks as proved by significant feeding rejection percentage and significant reduction in egg and engorgement weights of H. dromedarii. While insignificant protection was observed against O. savignyi ticks infestation in feeding rejection and reduction in engorgement weight. In conclusion, this study suggests promising immunoprophylactic potentials of the purified fractions against tick infestations in rabbits through induction of IgG responses. The protective effect of both vaccine candidates deserves further evaluation in other hosts and against other tick infestations.
Collapse
Affiliation(s)
- Nagwa I. Toaleb
- Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Centre, Dokki, Giza, Egypt
| | - Hanan S. M. Gabr
- Department of Zoology and Agricultural Nematology, Faculty of Agriculture, Cairo University, Giza, Egypt
| | - Sobhy Abd El-Shafy
- Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Centre, Dokki, Giza, Egypt
| | - Eman H. Abdel-Rahman
- Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Centre, Dokki, Giza, Egypt
| |
Collapse
|
22
|
Lima ADS, Landulfo GA, Costa-Junior LM. Repellent Effects of Encapsulated Carvacrol on the Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:881-885. [PMID: 30805609 DOI: 10.1093/jme/tjy240] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Indexed: 06/09/2023]
Abstract
Rhipicephalus (Boophilus) microplus (Canestrini) is a problem for livestock production systems, and its control has become challenging due to the selection of tick populations resistant to synthetic chemical acaricides. The use of repellent compounds prevents contact between the arthropod parasite and the host and can, thus, contribute to increases in the efficacy of these acaricides. Carvacrol monoterpenic phenol is a possible alternative method for controlling R. (B.) microplus; however, this compound is highly volatile, and its volatilization can be decreased through microencapsulation, which results in the timed release of the compound. The cell wall of Saccharomyces cerevisiae can be utilized for the protection of volatile molecules. The aim of this study was to evaluate the in vitro repellent effect of yeast cell wall-encapsulated carvacrol on susceptible R. (B.) microplus larvae. Specifically, the vertical filter paper bioassay was employed to analyze the repellent activity of encapsulated carvacrol, nonencapsulated carvacrol, and N,N-diethyl-meta-toluamide at concentrations ranging from 0.75 to 0.001 mg/cm2, and the repellent activities were evaluated. Both carvacrol and encapsulated carvacrol exhibited repellent effects on R. (B.) microplus larvae, and the encapsulated compound showed the highest repellent activities at the lowest concentrations. Carvacrol encapsulated exhibited a low repellent concentration in all times (≤0.05 mg/cm2), whereas the carvacrol nonencapsulated ranged CR50 from 0.13 to 0.27 mg/cm2 at 1- to 6-h posttreatment. The present paper provides the first description of the use of a microencapsulation technique for achieving the highest repellent effect of carvacrol and indicates that this technique might be used to obtain new delivery systems for volatile and hydrophobic compounds.
Collapse
Affiliation(s)
| | | | - Livio M Costa-Junior
- Departamento de Patologia, Universidade Federal do Maranhão - UFMA, Maranhão, Brazil
| |
Collapse
|
23
|
A countrywide molecular survey leads to a seminal identification of the invasive cattle tick Rhipicephalus (Boophilus) microplus in Cameroon, a decade after it was reported in Cote d'Ivoire. Ticks Tick Borne Dis 2019; 10:585-593. [PMID: 30765191 PMCID: PMC6446184 DOI: 10.1016/j.ttbdis.2019.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 12/17/2018] [Accepted: 02/04/2019] [Indexed: 12/02/2022]
Abstract
The cattle tick Rhipicephalus microplus is the most important arthropod vector of livestock diseases globally. Since its introduction in West Africa a decade ago, it has been reported in Ivory Coast, Benin, Togo, Mali, Burkina Faso and Nigeria with potentially far-reaching adverse impacts on the livestock sector in the region. Cameroon is located on a major route for transboundary cattle trade between Central and West Africa and it is therefore at risk from R. microplus invasion. This study investigated the occurrence of R. microplus in Cameroon, the genetic polymorphism of the tick and population structure of isolates from different regions of the country to provide data that underpin the design of future vector control programs. A cross-sectional survey was conducted in which ticks were collected from cattle at 54 sites across the five Agroecological zones (AEZs) within Cameroon. Tick identity (sex and species) was assigned using taxonomic keys. Species identity was confirmed through amplification and sequencing of the mitochondrial COI and 16S rRNA genes. A total of 7091 ticks were collected out of which 1112 (15.6%) were morphologically identified as R. microplus. The presence of R. microplus was confirmed in 4 out of 5 agroecological zones. Only two haplotypes were identified by both COI and 16S rRNA genes, indicating a very low divergence in the genetic structure of the R. microplus population in Cameroon. 16S rRNA sequence analysis revealed a new haplotype specific to Cameroon. Phylogenetic trees revealed that all isolates of R. microplus from Cameroon were grouped into the previously described Africa/Americas clade. Application of a niche modelling algorithm to R. microplus distribution in Cameroon predicted that suitable habitat for the tick extended into southern Nigeria. This study demonstrated for the first time the presence of R. microplus in Cameroon. Genetic diversity tests indicate that the tick has not evolved significantly since the initial introduction to West Africa. We suggest further longitudinal studies to better define the spatial and temporal expansion of the range of the tick and the drivers of this spread.
Collapse
|
24
|
The genetic relationship between R. microplus and R. decoloratus ticks in South Africa and their population structure. Mol Phylogenet Evol 2018; 129:60-69. [PMID: 30102976 DOI: 10.1016/j.ympev.2018.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 07/10/2018] [Accepted: 08/03/2018] [Indexed: 11/22/2022]
Abstract
Rhipicephalus microplus and R. decoloratus are one-host ticks that preferentially feed on cattle. They are capable of transmitting various tick-borne pathogens which may be detrimental to the agricultural and livestock industry in South Africa. Previous studies have shown that R. microplus forms five lineages in the R. microplus complex, segregating into different geographical areas based on mitochondrial markers. This study examined the phylogenetic relationship within and between R. microplus and R. decoloratus using the nuclear internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome oxidase subunit I (COI) genes. The results showed that the nuclear ITS2 marker is informative for interspecific variation but lacks the resolution for intraspecific variation. Analysis of the mitochondrial COI gene revealed that R. microplus ticks from South Africa grouped into a clade comprised of ticks from Asia and South America. The population structure of these two tick species was also investigated using novel microsatellite markers. Population structure analyses revealed that both the R. microplus and R. decoloratus populations presented with two genetic clusters. Rhipicephalus microplus ticks from the Kwa-Zulu Natal (KZN) province belonged to cluster 1, and those from the Eastern Cape (EC) province predominantly grouped into cluster 2. No observable population structure was noted for R. decoloratus. The overlap of genetic clusters in both species could be attributed to inbreeding between the regions by unrestricted movement of cattle across provinces. Such movement promotes tick mobility, gene flow and the homogenisation of tick populations.
Collapse
|
25
|
Robbertse L, Richards SA, Clift SJ, Barnard AC, Leisewitz A, Crafford JE, Maritz-Olivier C. Comparison of the differential regulation of T and B-lymphocyte subsets in the skin and lymph nodes amongst three cattle breeds as potential mediators of immune-resistance to Rhipicephalus microplus. Ticks Tick Borne Dis 2018; 9:976-987. [PMID: 29622516 DOI: 10.1016/j.ttbdis.2018.03.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/02/2018] [Accepted: 03/30/2018] [Indexed: 12/20/2022]
Abstract
Although varying natural resistance to ticks between highly resistant Brahman (Bos taurus indicus), resistant Bonsmara (5/8 B. t. indicus x 3/8 B. t. taurus) and susceptible Holstein-Friesian (B. t. taurus) breeds is documented in skin and blood, little information is available describing draining lymph nodes. To elucidate the cellular dynamics during Rhipicephalus microplus induced immune responses, this study analysed immune factors from these cattle breeds using histology, immunohistochemistry and flow cytometry. Following the collection of skin and lymph node samples before artificial tick infestation, cattle were infested with R. microplus larvae. Subsequent sampling coincided with the tick larvae and adult developmental stages. A significant influx of CD20+ B-lymphocytes in the dermis all cattle breeds was observed while CD3+ T-lymphocytes were significantly increased for more tick resistant breeds. Eosinophil infiltration in germinal centres of lymph nodes was significant for all cattle breeds while tingible body macrophages were significantly increased for adult infested Brahman animals. A negligible fluctuation in CD20+ and CD79α+ B-lymphocyte numbers was present in the lymph node of more resistant cattle breeds, while susceptible animals showed a decrease in B-lymphocytes after infestation, followed by an increase between larvae to adult infested time points. Increased variability of γd T-lymphocyte populations in lymph nodes was correlated with tick susceptibility. In addition, a more stable T helper lymphocyte population was identified in the lymph nodes for the Brahman cattle breed. Results suggest the association of tick susceptibility with differential B-lymphocyte regulation in lymph node tissues, increased variability of WC1+ γδ T-lymphocyte populations in the lymph node as well as a decrease in T helper lymphocytes in the lymph node.
Collapse
Affiliation(s)
- Luïse Robbertse
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of Pretoria, South Africa
| | - Sabine Annette Richards
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of Pretoria, South Africa
| | - Sarah Jane Clift
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - Annette-Christi Barnard
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of Pretoria, South Africa
| | - Andrew Leisewitz
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - Jan Ernst Crafford
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - Christine Maritz-Olivier
- Department of Genetics, Faculty of Natural and Agricultural Sciences, University of Pretoria, South Africa.
| |
Collapse
|
26
|
Rodriguez-Vivas RI, Jonsson NN, Bhushan C. Strategies for the control of Rhipicephalus microplus ticks in a world of conventional acaricide and macrocyclic lactone resistance. Parasitol Res 2018; 117:3-29. [PMID: 29152691 PMCID: PMC5748392 DOI: 10.1007/s00436-017-5677-6] [Citation(s) in RCA: 153] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/06/2017] [Indexed: 12/11/2022]
Abstract
Infestations with the cattle tick, Rhipicephalus microplus, constitute the most important ectoparasite problem for cattle production in tropical and subtropical regions worldwide, resulting in major economic losses. The control of R. microplus is mostly based on the use of conventional acaricides and macrocyclic lactones. However, the intensive use of such compounds has resulted in tick populations that exhibit resistance to all major acaricide chemical classes. Consequently, there is a need for the development of alternative approaches, possibly including the use of animal husbandry practices, synergized pesticides, rotation of acaricides, pesticide mixture formulations, manual removal of ticks, selection for host resistance, nutritional management, release of sterile male hybrids, environmental management, plant species that are unfavourable to ticks, pasture management, plant extracts, essential oils and vaccination. Integrated tick management consists of the systematic combination of at least two control technologies aiming to reduce selection pressure in favour of acaricide-resistant individuals, while maintaining adequate levels of animal production. The purpose of this paper is to present a current review on conventional acaricide and macrocyclic lactone resistance for better understanding and control of resistant ticks with particular emphasis on R. microplus on cattle.
Collapse
Affiliation(s)
- Roger I Rodriguez-Vivas
- Facultad de Medicina Veterinaria y Zootecnia, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, km. 15.5 Carretera Mérida-Xmatkuil, 97000, Mérida, Yucatán, Mexico.
| | - Nicholas N Jonsson
- College of Medical, Veterinary and Life Sciences, University of Glasgow, G61 1QH, Glasgow, UK
| | - Chandra Bhushan
- Bayer Animal Health GmbH, Kaiser-Wilhelm-Alee 10, 51368, Leverkusen, Germany
| |
Collapse
|
27
|
Rosado-Aguilar JA, Rodríguez-Vivas RI, Borges-Argaez R, Arjona-Cambranes KA. Acaricidal activity of Havardia albicans and Caesalpinia gaumeri methanolic leaf extracts on Rhipicephalus microplus and its toxicity to laboratory animals. EXPERIMENTAL & APPLIED ACAROLOGY 2017; 71:345-354. [PMID: 28497304 DOI: 10.1007/s10493-017-0130-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 04/23/2017] [Indexed: 06/07/2023]
Abstract
The acaricidal activity of methanolic extracts from the leaves of Havardia albicans (Kunth Britton and Rose) and Caesalpinia gaumeri (Greenm) were tested on the larvae and adults of the cattle tick Rhipicephalus microplus Canestrini using the larval immersion test and the adult immersion test, respectively. The toxicity of these extracts was also evaluated on laboratory animals using toxicity bioassays at different concentrations: skin irritability (500 mg/ml), acute oral toxicity (5000 mg/kg), ocular irritability (1000 mg/ml) and dermal toxicity (5000 mg/kg). The acaricidal activity of the H. albicans extracts on R. microplus larvae showed a LC50 of 7.0% (4.3-11.4) and a LC99 of 25.5% (14.26-201.5). The acaricidal activity of the C. gaumeri extracts on larvae showed a LC50 of 7.8% (5.74-10.65) and a LC99 of 38.32% (22.22-146.48). The H. albicans extracts showed moderate acaricidal activity in the inhibition of egg laying (54.4 ± 12.4) and the inhibition of larval hatching (48.7 ± 6.8) in R. microplus adults. The C. gaumeri extracts also showed moderate acaricidal activity in the inhibition of egg laying (51.0 ± 11.2). However, none of the evaluated extracts showed significant toxicity on laboratory rodents. These plants show the potential to control R. microplus and could be administered topically or orally in animals. Further studies are needed to identify the active compound(s) and to evaluate the effects of these plants on R. microplus in vivo.
Collapse
Affiliation(s)
- José A Rosado-Aguilar
- Laboratorio de Parasitología. Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km. 15.5 carretera Mérida-Xmatkuil, CP 97100, Mérida, Yucatán, Mexico.
| | - Roger I Rodríguez-Vivas
- Laboratorio de Parasitología. Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km. 15.5 carretera Mérida-Xmatkuil, CP 97100, Mérida, Yucatán, Mexico
| | - Rocío Borges-Argaez
- Centro de Investigación Científica de Yucatán, Calle 43 No 130 Colonia Chuburná de Hidalgo, CP 97200, Mérida, Yucatán, Mexico
| | - Karen A Arjona-Cambranes
- Laboratorio de Parasitología. Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km. 15.5 carretera Mérida-Xmatkuil, CP 97100, Mérida, Yucatán, Mexico
| |
Collapse
|
28
|
MANJUNATHACHAR HV, SARAVANAN BC, KUMAR BINOD, TAMILMAHAN P, SHARMA ANILKUMAR, SHINDE SANTHOSH, NANDI ABHIJIT, NAGAR GAURAV, CHIGURE GAJANAN, MOHMAD AQUIL, FULAR ASHUTOSH, KUMAR SACHIN, GHOSH SRIKANT. Expression and determination of immunization dose of recombinant tropomyosin protein of Hyalomma anatolicum for the development of anti-tick vaccine. THE INDIAN JOURNAL OF ANIMAL SCIENCES 2017. [DOI: 10.56093/ijans.v87i3.68841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Present investigation was carried out to standardize the immunization dose of one recombinant antigen in rat model before conducting large animal experimentation. Tropomyosin (TPM), a muscle associated and highly conserved protein found in all species of invertebrates, was cloned, expressed in prokaryotic system and the downstream process was standardized. SDS-PAGE analysis showed a distinct band of approximately 51 kDa Western blot analysis using specific sera gave a strong reaction of approximately the same size as that of SDSPAGE. For standardization of immunization dose, the rTPM at three different dosages viz., 150, 300, 450 μg was used to immunize wister rats and the antibody response was titrated by ELISA. Applying ANOVA, highly significantdifference in anti-rTPM titre was recorded between the animals injected with 300 μg total dose (TD) and other dosages selected for the study. The significantly high antibody tire at 1:25600 dilution observed in animals immunized with 300 μg TD was selected for further study on in vivo immunization of calves and experimental challenge by the tick stages.
Collapse
|
29
|
Ferritin 1 silencing effect in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) during experimental infection with Ehrlichia canis. Ticks Tick Borne Dis 2017; 8:174-184. [DOI: 10.1016/j.ttbdis.2016.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 10/24/2016] [Accepted: 10/27/2016] [Indexed: 11/24/2022]
|
30
|
Arceo-Medina GN, Rosado-Aguilar JA, Rodríguez-Vivas RI, Borges-Argaez R. Synergistic action of fatty acids, sulphides and stilbene against acaricide-resistant Rhipicephalus microplus ticks. Vet Parasitol 2016; 228:121-125. [PMID: 27692312 DOI: 10.1016/j.vetpar.2016.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/29/2016] [Accepted: 08/31/2016] [Indexed: 10/21/2022]
Abstract
Six compounds in a methanolic extract of Petiveria alliacea stem (cis-stilbene; benzyl disulphide; benzyl trisulphide; and methyl esters of hexadecanoic acid, octadecadienoic acid and octadecenoic acid) are known to exercise acaricide activity against cattle tick Rhipicephalus microplus larvae and adults. The synergistic effect of 57 combinations of these six compounds on acaricide activity against R. microplus was evaluated. Larvae immersion tests produced the lethal concentrations needed to kill 50% (LC50) and 99% (LC99) of the population. Adult immersion tests produced rates (%) for mortality, oviposition inhibition and eclosion inhibition. Individually, none of the compounds (1% concentration) exhibited acaricide activity (mortality ≤2.3%). When combined, however, nine mixtures exhibited a synergistic increase in activity, with high mortality rates (≥92%) in larvae. Values for LC50 ranged from 0.07 to 0.51% and those for LC99 from 0.66 to 5.16%. Thirty six compound mixtures had no significant activity (mortality ≤30%) against larvae. Two mixtures exhibited synergism against adults, with high rates (≥92%) of oviposition inhibition. The mixtures based on the benzyl disulphide+benzyl trisulphide pairing produced a synergistic effect against acaricide-resistant R. microplus larva and adults, and are therefore the most promising combination for controlling this ubiquitous ectoparasite.
Collapse
Affiliation(s)
- G N Arceo-Medina
- Laboratorio de Parasitología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Carretera Mérida-Xmatkuil Km. 15.5, 97100 Mérida, Yucatán, Mexico
| | - J A Rosado-Aguilar
- Laboratorio de Parasitología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Carretera Mérida-Xmatkuil Km. 15.5, 97100 Mérida, Yucatán, Mexico.
| | - R I Rodríguez-Vivas
- Laboratorio de Parasitología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Carretera Mérida-Xmatkuil Km. 15.5, 97100 Mérida, Yucatán, Mexico
| | - R Borges-Argaez
- Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Col. Chuburná de Hidalgo, 97200 Mérida, Yucatán, Mexico
| |
Collapse
|
31
|
Genetic diversity, acaricide resistance status and evolutionary potential of a Rhipicephalus microplus population from a disease-controlled cattle farming area in South Africa. Ticks Tick Borne Dis 2016; 7:595-603. [DOI: 10.1016/j.ttbdis.2016.02.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 02/02/2016] [Accepted: 02/24/2016] [Indexed: 11/22/2022]
|
32
|
Survey of cattle tick, Riphicephalus (Boophilus) microplus, resistance to amitraz and deltamethrin in New Caledonia. Vet Parasitol 2016; 217:64-70. [DOI: 10.1016/j.vetpar.2015.12.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 12/01/2015] [Accepted: 12/12/2015] [Indexed: 11/19/2022]
|
33
|
Wyk RDV, Baron S, Maritz-Olivier C. An integrative approach to understanding pyrethroid resistance in Rhipicephalus microplus and R. decoloratus ticks. Ticks Tick Borne Dis 2016; 7:586-94. [PMID: 26851840 DOI: 10.1016/j.ttbdis.2016.01.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 01/08/2016] [Accepted: 01/15/2016] [Indexed: 11/18/2022]
Abstract
Rhipicephalus microplus and Rhipicephalus decoloratus species occur in regions with savannah and temperate climates, typically in grassland and wooded areas used as cattle pasture. Both species are associated with the transmission of Anaplasma and Babesia spp., impacting livestock health and quality of livestock-associated products. In Africa, tick control is predominantly mediated with the use of acaricides, such as synthetic pyrethroids. After several years on the market, reports of resistance to synthetic pyrethroids escalated but limited field data and validation studies have been conducted to determine the extent of acaricide resistance in Africa. Without this data, knowledge-based tick control will remain problematic and selection pressure will remain high increasing the rate of resistance acquisition. To date, several pyrethroid resistance associated single nucleotide polymorphisms (SNPs) have been reported for arthropods within the voltage-gated sodium channel. Three SNPs have been identified within this channel in pyrethroid resistant R. microplus ticks, but none has been reported for R. decoloratus. This study is the first to report the presence of a shared SNP within the voltage-gated sodium channel in both R. microplus and R. decoloratus, which is directly linked to pyrethroid resistance in R. microplus. As the mode of action by which these SNPs mediate pyrethroid resistance remains unknown, this study aims to set hypotheses by means of predictive structural modelling. This not only paves the way forward to elucidating the underlying biological mechanisms involved in pyrethroid resistance, but also improvement of existing acaricides and ultimately sustainable tick control management.
Collapse
Affiliation(s)
- Roelof Dj van Wyk
- Department of Biochemistry, University of Pretoria, Pretoria, South Africa
| | - Samantha Baron
- Department of Genetics, University of Pretoria, Pretoria, South Africa
| | | |
Collapse
|
34
|
Uys AC, Horak IG, Harrison A. Questing ixodid ticks on the vegetation of sable antelope and multi-herbivore enclosures in Thabazimbi. J S Afr Vet Assoc 2015; 86:1243. [PMID: 26244584 PMCID: PMC6138072 DOI: 10.4102/jsava.v86i1.1243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 04/17/2015] [Accepted: 05/11/2015] [Indexed: 11/11/2022] Open
Abstract
This survey of ixodid ticks was the first to compare the species composition and population dynamics of free-living ticks in intensive, sable antelope breeding enclosures, now commonplace in commercial wildlife ranching in South Africa, with those of multi-herbivore enclosures. The species composition, abundance and seasonal abundance of questing ixodid ticks on the vegetation in intensive breeding enclosures for sable antelope (Hippotragus niger), on which strategic tick control is practised, were compared with those of ticks in a multi-species herbivore enclosure surrounding the breeding enclosures in which no tick control is practised. A total of eight ixodid tick species were collected by drag-sampling the woodland and grassland habitats in each enclosure type monthly from July 2011 to July 2013. Rhipicephalus decoloratus, a potential vector of fatal tick-borne disease in sable antelopes, was the most abundant, accounting for 65.4% of the total number of ticks collected in the sable enclosures, whilst representing only 25.4% of number of ticks collected in the multi-species herbivore enclosure. Rhipicephalus decoloratus and R. evertsi evertsi were more abundant than R. appendiculatus (both p < 0.05) and Amblyomma hebraeum (p < 0.001 and p < 0.01, respectively). Rhipicephalus decoloratus larvae were collected throughout the year, with peak collections in November 2012 and October to December 2013 in the sable enclosures; and in April/May 2012 and February/April 2013 in the multi-species herbivore enclosure. More R. decoloratus were recovered in the second year than in the first year in the grassland habitat of the sable enclosures (V = 7.0, p < 0.05) possibly as a result of acaricide resistance. The apparent temporal over-abundance of R. decoloratus in sable antelope breeding enclosures, in the face of strategic tick control, is of concern and requires further investigation.
Collapse
|
35
|
Lu S, Soares TS, Vaz Junior IS, Lovato DV, Tanaka AS. Rmcystatin3, a cysteine protease inhibitor from Rhipicephalus microplus hemocytes involved in immune response. Biochimie 2014; 106:17-23. [DOI: 10.1016/j.biochi.2014.07.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
|
36
|
Stone NE, Olafson PU, Davey RB, Buckmeier G, Bodine D, Sidak-Loftis LC, Giles JR, Duhaime R, Miller RJ, Mosqueda J, Scoles GA, Wagner DM, Busch JD. Multiple mutations in the para-sodium channel gene are associated with pyrethroid resistance in Rhipicephalus microplus from the United States and Mexico. Parasit Vectors 2014; 7:456. [PMID: 25266983 PMCID: PMC4189684 DOI: 10.1186/s13071-014-0456-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 09/20/2014] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Acaricide resistant Rhipicephalus microplus populations have become a major problem for many cattle producing areas of the world. Pyrethroid resistance in arthropods is typically associated with mutations in domains I, II, III, and IV of voltage-gated sodium channel genes. In R. microplus, known resistance mutations include a domain II change (C190A) in populations from Australia, Africa, and South America and a domain III mutation (T2134A) that only occurs in Mexico and the U.S. METHODS We investigated pyrethroid resistance in cattle fever ticks from Texas and Mexico by estimating resistance levels in field-collected ticks using larval packet discriminating dose (DD) assays and identifying single nucleotide polymorphisms (SNPs) in the para-sodium channel gene that associated with resistance. We then developed qPCR assays for three SNPs and screened a larger set of 1,488 R. microplus ticks, representing 77 field collections and four laboratory strains, for SNP frequency. RESULTS We detected resistance SNPs in 21 of 68 U.S. field collections and six of nine Mexico field collections. We expected to identify the domain III SNP (T2134A) at a high frequency; however, we only found it in three U.S. collections. A much more common SNP in the U.S. (detected in 19 of 21 field collections) was the C190A domain II mutation, which has never before been reported from North America. We also discovered a novel domain II SNP (T170C) in ten U.S. and two Mexico field collections. The T170C transition mutation has previously been associated with extreme levels of resistance (super-knockdown resistance) in insects. We found a significant correlation (r = 0.81) between the proportion of individuals in field collections that carried any two resistance SNPs and the percent survivorship of F1 larvae from these collections in DD assays. This relationship is accurately predicted by a simple linear regression model (R2 = 0.6635). CONCLUSIONS These findings demonstrate that multiple mutations in the para-sodium channel gene independently associate with pyrethroid resistance in R. microplus ticks, which is likely a consequence of human-induced selection.
Collapse
Affiliation(s)
- Nathan E Stone
- />Center for Microbial Genetics and Genomics, Northern Arizona University, 1298 S Knoles Drive, Flagstaff, AZ 86011-4073 USA
| | - Pia U Olafson
- />USDA, ARS, Knipling-Bushland United States Livestock Insects Research Laboratory, 2700 Fredericksburg Rd, Kerrville, TX 78028 USA
| | - Ronald B Davey
- />USDA, ARS, SPA, Cattle Fever Tick Research Laboratory, Moore Air Base, Building 6419, 22675 N. Moorefield Road, Edinburg, TX 78541 USA
| | - Greta Buckmeier
- />USDA, ARS, Knipling-Bushland United States Livestock Insects Research Laboratory, 2700 Fredericksburg Rd, Kerrville, TX 78028 USA
| | - Deanna Bodine
- />USDA, ARS, Knipling-Bushland United States Livestock Insects Research Laboratory, 2700 Fredericksburg Rd, Kerrville, TX 78028 USA
| | - Lindsay C Sidak-Loftis
- />Center for Microbial Genetics and Genomics, Northern Arizona University, 1298 S Knoles Drive, Flagstaff, AZ 86011-4073 USA
| | - John R Giles
- />Environmental Futures Research Institute, Griffith University, Brisbane, 4111 Australia
| | - Roberta Duhaime
- />USDA-APHIS, Veterinary Services, 903 San Jacinto Blvd., Room 220, Austin, TX 78701 USA
| | - Robert J Miller
- />USDA, ARS, SPA, Cattle Fever Tick Research Laboratory, Moore Air Base, Building 6419, 22675 N. Moorefield Road, Edinburg, TX 78541 USA
| | - Juan Mosqueda
- />Universidad Autónoma de Querétaro, Av. de las Ciencias S/N, Juriquilla, Queretaro, C.P 76230 Mexico
| | - Glen A Scoles
- />USDA, ARS, Animal Disease Research Unit, 3003 ADBF, Washington State University, Pullman, WA 99164 USA
| | - David M Wagner
- />Center for Microbial Genetics and Genomics, Northern Arizona University, 1298 S Knoles Drive, Flagstaff, AZ 86011-4073 USA
| | - Joseph D Busch
- />Center for Microbial Genetics and Genomics, Northern Arizona University, 1298 S Knoles Drive, Flagstaff, AZ 86011-4073 USA
| |
Collapse
|
37
|
Kabi F, Masembe C, Muwanika V, Kirunda H, Negrini R. Geographic distribution of non-clinical Theileria parva infection among indigenous cattle populations in contrasting agro-ecological zones of Uganda: implications for control strategies. Parasit Vectors 2014; 7:414. [PMID: 25175844 PMCID: PMC4261563 DOI: 10.1186/1756-3305-7-414] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 08/26/2014] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Non-clinical Theileria parva infection among indigenous cattle occurs upon recovery from primary disease during the first year of life. Continuous exposure to infection through contaminated tick infestations with absence of clinical disease gives rise to endemic stability. Endemic stable populations may become sources of infection if contaminated tick vectors are shared with susceptible exotic cattle. This study aimed at establishing a nationwide distribution of non-clinical T. parva infection among indigenous cattle populations to inform novel control strategies. METHODS The occurrence of non-clinical T. parva infection among apparently healthy 925 indigenous cattle from 209 herds spread out in 10 agro-ecological zones (AEZs) was determined using a nested PCR assay. The influence of AEZ, breed, sex, age and farmers' ranking of ECF importance were interrogated for influence of non-clinical parasite occurrence. RESULTS The overall prevalence of non-clinical T. parva infection was 30% (278/925). A gradual increase of non-clinical T. parva infection was observed ranging from 17% (95% CI: 0.03-0.23) to 43% (95% CI: 0.3-0.55) in the North Eastern Savannah Grasslands (NESG) to the Western Highland Ranges (WHR) respectively. A similarly associated 18% (95% CI: 0.07-0.28) and 35% (95% CI: 0.3-0.39) non-clinical parasite prevalence was observed among the East African shorthorn Zebu (EASZ) and Ankole cattle respectively. Average herd level non-clinical T. parva prevalence was 28%, ranging from zero to 100%. The likelihood of non-clinical T. parva infection was 35.5% greater in the western highlands compared to the northeastern semi-arid AEZs. CONCLUSIONS Non-clinical T. parva occurs countrywide, structured along patterns of AEZ and breed gradients. These findings may guide policy formulation, deployment of integrated control strategies and local cattle improvement programs.
Collapse
Affiliation(s)
- Fredrick Kabi
- Department of Environmental Management, Molecular Genetics Laboratory, College of Agricultural and Environmental Sciences, Makerere University, P,O, Box 7062/7298 Kampala, Uganda.
| | | | | | | | | |
Collapse
|
38
|
Abbas RZ, Zaman MA, Colwell DD, Gilleard J, Iqbal Z. Acaricide resistance in cattle ticks and approaches to its management: The state of play. Vet Parasitol 2014; 203:6-20. [DOI: 10.1016/j.vetpar.2014.03.006] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 03/02/2014] [Accepted: 03/04/2014] [Indexed: 10/25/2022]
|
39
|
Duscher GG, Galindo RC, Tichy A, Hummel K, Kocan KM, de la Fuente J. Glutathione S-transferase affects permethrin detoxification in the brown dog tick, Rhipicephalus sanguineus. Ticks Tick Borne Dis 2014; 5:225-33. [PMID: 24548526 DOI: 10.1016/j.ttbdis.2013.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 10/22/2013] [Accepted: 11/03/2013] [Indexed: 10/25/2022]
Abstract
Control of ticks on dogs is often done by application of repellents that contain permethrin as the active ingredient. In this research, we studied the role of a glutathione S-transferase (GST) gene in detoxification of permethrin by ticks using a gene silencing method RNA interference (RNAi). The brown dog tick, Rhipicephalus sanguineus, used in these studies, has a notable host preference for dogs, but also infests other mammals. In this research, R. sanguineus females were injected with gst double-stranded RNA (dsRNA) to effect gene silencing by RNAi and then exposed to sublethal doses of permethrin. Sixty hours after injection, the females were allowed to feed on sheep. The female ticks subjected to RNAi proved to be more susceptible to permethrin than the untreated controls. The effect of gene silencing was most notable in the highest dose group (50.3 ppm) in which all ticks died, while in the corresponding controls that were not subjected to RNAi this dose was not lethal. The acaricide treatment of the ticks resulted in a change in tick attachment behavior. Acaricide-treated ticks attached in a scattered pattern in contrast to the control ticks that attached and fed tightly clustered together. The time required for repletion for both the injected and non-injected females exposed to the higher permethrin level was shorter than that observed in the lower-dose groups and unexposed controls, and this more rapid attachment and feeding would likely favor more rapid transmission of pathogens. However, engorgement and egg mass weights were not significantly different among the experimental groups. This research demonstrated that the silencing of the gst gene increased the tick's susceptibility to permethrin. Overall, these results have contributed to our understanding of the detoxification mechanism of ticks and provide new considerations for the formulation of treatment strategies.
Collapse
Affiliation(s)
- Georg Gerhard Duscher
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Vienna, Austria.
| | - Ruth Cecilia Galindo
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, USA; Institute for Population Genetics, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Austria
| | - Alexander Tichy
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ciudad Real, Spain
| | - Karin Hummel
- VetCore Facility for Research, University of Veterinary Medicine Vienna, Austria
| | - Katherine M Kocan
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, USA
| | - José de la Fuente
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, USA; Institute for Population Genetics, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Austria
| |
Collapse
|
40
|
Acaricide and ivermectin resistance in a field population of Rhipicephalus microplus (Acari: Ixodidae) collected from red deer (Cervus elaphus) in the Mexican tropics. Vet Parasitol 2013; 200:179-88. [PMID: 24365245 DOI: 10.1016/j.vetpar.2013.11.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/06/2013] [Accepted: 11/26/2013] [Indexed: 12/31/2022]
Abstract
In the Neotropics the control of tick infestations in red deer (Cervus elaphus) is achieved primarily through the use of acaricides and macrocyclic lactones. In Mexico, resistance to one or multiple classes of acaricides has been reported in Rhipicephalus microplus infesting cattle, but information on acaricide susceptibility in R. microplus infesting red deer is lacking. In this study we report the level of resistance to different classes of acaricides and ivermectin in R. microplus collected from red deer in the Mexican tropics. Engorged R. microplus females were collected from a red deer farm in Yucatan, Mexico. The larval packet test was used to detect resistance to the organophosphates (OPs) chlorpyrifos and coumaphos, synthetic pyrethroids (SPs) cypermethrin and permethrin, and the phenylpyrazol, fipronil. Resistance to the formamidine amitraz (Am), and ivermectin was ascertained using the larval immersion test. Data were subjected to probit analysis to determine lethal concentrations and resistance ratios to kill 50% (RR50) and 99% (RR99) of the tick population under evaluation in relation to susceptible reference strains. Additionally, allele specific polymerase chain reaction was used to detect the sodium channel F1550I mutation associated with SP resistance in R. microplus. The R. microplus population from red deer in Yucatan showed very high resistance to the two SPs evaluated (RRs>72.2 for cypermethrin; RR for permethrin resistance was so high a dose-response curve was not possible). All individual larvae tested to detect the sodium channel F1550I mutation associated with SP resistance in R. microplus were homozygous. The same tick population showed different levels of resistance to OPs (chlorpyrifos: RR50=1.55, RR99=0.63; coumaphos: RR50=6.8, RR99=5.9), fipronil (RR50=1.8, RR99=0.9), and amitraz (RR50=2.3, RR99=4.4). Resistance to ivermectin was regarded as moderate (RR50=7.1, RR99=5.0). This is the first report of R. microplus ticks collected from red deer in Mexico with different levels of resistance to four acaricide groups and ivermectin.
Collapse
|
41
|
Rodriguez-Vivas RI, Li AY, Ojeda-Chi MM, Trinidad-Martinez I, Rosado-Aguilar JA, Miller RJ, Pérez de León AA. In vitro and in vivo evaluation of cypermethrin, amitraz, and piperonyl butoxide mixtures for the control of resistant Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) in the Mexican tropics. Vet Parasitol 2013; 197:288-96. [PMID: 23948559 DOI: 10.1016/j.vetpar.2013.07.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 07/08/2013] [Accepted: 07/11/2013] [Indexed: 11/17/2022]
Abstract
A study was conducted to evaluate the efficacy of cypermethrin, amitraz, and piperonyl butoxide (PBO) mixtures, through in vitro laboratory bioassays and in vivo on-animal efficacy trials, for the control of resistant Rhipicephalus (Boophilus) microplus on cattle in the Mexican tropics. Also, to examine mechanisms of resistance to cypermethrin in this tick population, the frequency of a mutated sodium channel gene (F1550I) was determined using a PCR assay. Results of laboratory bioassays using modified larval packet tests revealed that cypermethrin toxicity was synergized by PBO (from 46.6-57.0% to 83.7-85.0% larval mortality; P<0.05). The cypermethrin and amitraz mixture showed an additive effect (from 46.6-57.0% to 56.0-74.3% larval mortality). Strong synergism was observed with the mixture of cypermethrin+amitraz+PBO and this mixture was the most effective killing resistant tick larvae in vitro (96.7-100% of larval mortality). Tick larvae surviving exposure to cypermethrin or mixtures either with amitraz and PBO in vitro showed 2.9-49.6 higher probability to present the mutated allele than those killed by acaricide treatment (P<0.05). In the in vivo trial, the mixtures containing cypermethrin+PBO (80.6-97.3%), and cypermethrin+amitraz (87.0-89.7%) were more efficacious than cypermethrin alone (76.3-80.5%). The highest level of efficacy was obtained with the mixture of cypermethrin+amitraz+PBO, which yielded >95% control that persisted for 28 days post-treatment against R. microplus infesting cattle when tested under field conditions in the Mexican tropics. Although this mixture is a potentially useful tool to combat pyrethroid resistance, a product based on an acaricide mixture like the one tested in this study has to be used rationally.
Collapse
Affiliation(s)
- R I Rodriguez-Vivas
- Cuerpo Académico de Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km. 15.5 carretera Mérida-Xmatkuil, CP. 97100, Mérida, Yucatán, Mexico.
| | | | | | | | | | | | | |
Collapse
|
42
|
Silva Filho M, Silva L, Fernandes R, Lopes G. Efeito do extrato aquoso e etanólico do angico preto sobre larvas de Rhipicephalus (Boophilus) microplus. ARQ BRAS MED VET ZOO 2013. [DOI: 10.1590/s0102-09352013000300003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rhipicephalus (Boophilus) microplus representa um grande problema na bovinocultura e o uso de acaricidas é a medida de controle profilático e terapêutico mais comum contra esses ectoparasitos. Os principais problemas relacionados com essa prática dizem respeito ao desenvolvimento de linhagens resistentes de carrapatos. Assim, objetivou-se determinar o efeito de extratos da casca de Anadenanthera macrocarpa sobre as larvas de R. (B.) microplus, obtidas de um pool de ovos, acondicionadas em tubo de polietileno. De acordo com os resultados, o extrato aquoso na concentração de 8,26mg.mL-1 causou 85% de mortalidade nas primeiras 12 horas. Quanto ao extrato etanólico, observou-se maior mortalidade nas concentrações 12,5; 6,25 e 1,56mg.mL-1, em torno de 84%, percentuais semelhantes ao amitraz. Os controles negativos não apresentaram mortalidade durante o experimento. Assim, tanto o extrato aquoso como o extrato etanólico apresentaram efeito larvicida, embora o extrato etanólico tenha sido mais eficiente para a espécie, podendo ser uma alternativa no controle desse ectoparasito.
Collapse
|
43
|
Immune Response of Bos indicus Cattle against the Anti-Tick Antigen Bm91 Derived from Local Rhipicephalus (Boophilus) microplus Ticks and Its Effect on Tick Reproduction under Natural Infestation. J Parasitol Res 2012; 2012:907607. [PMID: 23213489 PMCID: PMC3507137 DOI: 10.1155/2012/907607] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 10/16/2012] [Accepted: 10/19/2012] [Indexed: 11/22/2022] Open
Abstract
Antigens of anti-tick vaccines are more efficacious for homologous challenge with local tick strains. cDNA clones encoding for Bm91 from local Rhipicephalus (Boophilus) microplus strains were developed to immunize Bos indicus cattle under field conditions. Three groups of six animals each were injected with the antigen Bm91, saline, and adjuvant, respectively. Animals were immunized three times at 3-week intervals and a fourth time after six months. The anti-Bm91 antibody level, measured by ELISA, was monitored for 7 months and the reproductive performance of naturally infested R. (B.) microplus was determined. Bm91-immunized animals developed a strong immune response expressed by high anti-Bm91 levels remaining on high levels until the end of the study. Western blot analysis confirmed that Bm91 is immunogenic. Compared to control animals, the reproductive efficiency index and the egg viability were 6% and 8%, respectively, lower in the Bm91 group (P < 0.05). In conclusion, it was demonstrated that Bm91 induced a long-lasting immune response. However, the effect on the tick reproduction was not sufficient for an efficient tick control. Further studies under field conditions are warranted to enhance the effect on the tick reproduction by optimizing the immunization regimen, alone or in combination with other vaccine candidate antigens.
Collapse
|
44
|
Parizi LF, Githaka NW, Logullo C, Konnai S, Masuda A, Ohashi K, da Silva Vaz I. The quest for a universal vaccine against ticks: Cross-immunity insights. Vet J 2012; 194:158-65. [DOI: 10.1016/j.tvjl.2012.05.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 03/19/2012] [Accepted: 05/23/2012] [Indexed: 10/28/2022]
|
45
|
The prevalence of pyrethroid resistance phenotype and genotype in Rhipicephalus (Boophilus) microplus in Yucatan, Mexico. Vet Parasitol 2011; 184:221-9. [PMID: 21978740 DOI: 10.1016/j.vetpar.2011.09.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Revised: 08/30/2011] [Accepted: 09/08/2011] [Indexed: 11/20/2022]
Abstract
A field survey was conducted to evaluate susceptibility of Rhipicephalus (Boophilus) microplus to cypermethrin on 49 farms in three areas of Yucatan, Mexico. The modified larval packet test was used to evaluate larval mortality at different cypermethrin concentrations. Dose-mortality regressions, lethal concentrations (LC(50)-LC(99)), confidence intervals and slope were estimated by probit analysis. Phenotype was defined as susceptible, tolerant or resistant when the resistance factor (RF) derived from both LC(50) and LC(99) determinations were <3, 3-5 or >5, respectively. An allele specific PCR (AS-PCR) was used to determine the frequency of a sodium channel mutation (F1550I, Phe→Ile) associated with pyrethroid resistance. Overall, 26.5%, 40.8% and 32.6% of tick populations were susceptible, tolerant and resistant to cypermethrin, respectively. A substantial inter-population variation in the level of cypermethrin response was evident (resistance factors ranged from 0.3 to 2599 and from 0.7 to >5000 when were indicated by the LC(50) and LC(99), respectively). The F1550I mutation (R allele) in R. microplus was present in all studied areas. The increasing presence of the R allele correlated well with increased levels of response indicated by both the LC(50) (r(2)=0.659, p=0.001) and LC(99) (r(2)=0.688, p=0.001) to cypermethrin. These results indicated that the F1550I mutation is a major common mechanism responsible for pyrethroid resistance in field populations of R. microplus ticks in the Mexican tropics. Both bioassay and AS-PCR showed that the prevalence of cypermethrin-resistant/tolerant R. microplus is high in Yucatan, Mexico and the relationship between the RF and the frequency of the R allele supports the role of F1550I as one of the most important mechanisms conferring pyrethroid resistance in these R. microplus populations.
Collapse
|