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Lifschitz A, Nava S, Miró V, Canton C, Alvarez L, Lanusse C. Macrocyclic lactones and ectoparasites control in livestock: Efficacy, drug resistance and therapeutic challenges. Int J Parasitol Drugs Drug Resist 2024; 26:100559. [PMID: 39128184 DOI: 10.1016/j.ijpddr.2024.100559] [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: 05/28/2024] [Revised: 07/30/2024] [Accepted: 08/07/2024] [Indexed: 08/13/2024]
Abstract
Macrocyclic lactones (MLs) are the cornerstone of parasite control in livestock due to their broad-spectrum activity against endo (nematodes) and ecto (lice, ticks, mites) parasites. These molecules, introduced into the veterinary pharmaceutical market 40 years ago, have substantially improved animal welfare and productivity by offering extended high efficacy, reducing treatment frequency, and displaying a favorable safety profile. However, their widespread and intensive use has led to a significant challenge nowadays: the development of parasite resistance. This review focuses on the critical link between drug pharmacokinetics (variation in concentration profiles and exposure over time) and pharmacodynamics (drug efficacy) and the ability of both avermectin and milbemycin MLs families to control livestock ectoparasites. This review discusses the integrated assessment of drug behavior in the host, its diffusion into target parasites, and the impact of different pharmaceutical formulations on enhancing drug delivery to infection sites. These are considered critical research/development areas to optimize the use of MLs, preventing treatment failures and finally extending the lifespan of these essential pharmaceutical ingredients. Finally, the importance of the rational use of MLs, guided by parasite epidemiology and pharmacological knowledge, is emphasized as a key strategy to preserve the antiparasitic efficacy of these still very useful molecules.
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Affiliation(s)
- A Lifschitz
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina.
| | - S Nava
- Instituto de Investigación de la Cadena Láctea (IdICaL)(INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, INTA E.E.A, Rafaela, Santa Fe, Argentina
| | - V Miró
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - C Canton
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - L Alvarez
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
| | - C Lanusse
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Campus Universitario, Tandil, Buenos Aires, Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, Campus Universitario, Tandil, Buenos Aires, Argentina
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Klafke GM, Golo PS, Monteiro CMO, Costa-Júnior LM, Reck J. Brazil's battle against Rhipicephalus (Boophilus) microplus ticks: current strategies and future directions. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA = BRAZILIAN JOURNAL OF VETERINARY PARASITOLOGY : ORGAO OFICIAL DO COLEGIO BRASILEIRO DE PARASITOLOGIA VETERINARIA 2024; 33:e001423. [PMID: 38922203 PMCID: PMC11253825 DOI: 10.1590/s1984-29612024026] [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: 01/18/2024] [Accepted: 03/26/2024] [Indexed: 06/27/2024]
Abstract
Ticks are parasitic arthropods that cause significant economic losses to livestock production worldwide. Although Rhipicephalus (Boophilus) microplus, the cattle tick, occurs throughout the Brazilian territory, there is no official program to control this tick, which is the vector of tick fever pathogens. We address the situation of R. (B.) microplus resistance to synthetic acaricides in Brazil, including cattle tick management; the status of tick resistance per Brazilian state; the history of resistance occurrence of different acaricides; multiple resistance occurrence; and the main strategies for integrated tick management. Tick control in Brazil is characterized by management errors. Local laboratories affiliated with federal and state research institutions and universities employ the Adult Immersion Test as a primary diagnostic method to assess acaricide resistance to topically applied drugs. Only three states (Acre, Amapá, and Amazonas) have no reports on resistant populations. Misinformation on tick control strategies, misuse of available products for tick control, no adoption of Integrated Parasite Management (IPM) practices, low technical support to producers, and the high-speed emergence of acaricide-resistant tick populations are the main problems. We also propose a list of needs and priorities for cattle tick control regarding communication, research, and policies.
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Affiliation(s)
| | - Patrícia Silva Golo
- Universidade Federal Rural do Rio de Janeiro – UFRRJ, Seropédica, RJ, Brasil
| | | | | | - José Reck
- Instituto de Pesquisas Veterinárias Desidério Finamor – IPVDF, Eldorado do Sul, RS, Brasil
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Nava S, Rossner MV, Toffaletti JR, Da Luz M, Rossner MB, Signorini M, Morel N. Strategic control of the cattle tick Rhipicephlaus microplus applied to rotational and silvopastoral grazing systems in subtropical areas. Parasitol Res 2024; 123:232. [PMID: 38847882 DOI: 10.1007/s00436-024-08256-4] [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: 11/29/2023] [Accepted: 05/29/2024] [Indexed: 07/04/2024]
Abstract
This work evaluated if strategic control based on no more than three or four annual treatments is useful to control Rhipicephalus microplus infestations on cattle when it is applied to intensive rotational grazing and silvopastoral systems with high stocking rates in subtropical areas. In the intensive rotational grazing system, three annual treatments with chemical acaricides were applied on cattle in two different schemes: between spring and early summer and from late winter and late spring. Strategic control based on three treatments with chemical acaricides from late winter to late spring plus an additional fourth treatment in summer was tested in the silvopastoral system. In the intensive rotational grazing systems, the control schemes allow to reach a significant reduction in the tick load on cattle considering a time interval from spring to autumn. However, the efficacy levels were not high enough in some specific moments, namely, the tick counts of summer and autumn (there were not significant differences between treated and control groups). The scheme evaluated in the silvopastoral grazing system yielded better results than those tested for the intensive rotational system, because significant differences in tick load between treated and control groups were observed in all post-treatment counts and when the analysis was performed for the whole study period. However, values of efficacy in the count-by-count comparison were disparate, ranging from 64.1 to 99.7. Although the efficacy values obtained in the silvopastoral system were better than those of the rotational grazing systems, the total tick load on treated cattle in autumn was not low enough (mean abundance values 25.14 and 38.14). Ticks were more evenly distributed among hosts in late summer and autumn than in spring or early summer, where few hosts carry most of the ticks. Some management strategies as intensive rotational systems or silvopastoral structures can lead to a more efficient forage use, but they imply greater tick challenge than in extensive grazing systems. In these situations, the schemes of strategic control bases on three or four annual treatments should be complemented with additional tactical treatments in late summer or autumn.
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Affiliation(s)
- Santiago Nava
- IDICAL (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria (INTA) E.E.A. Rafaela, Ruta 34 Km 227, Rafaela, Santa Fe, Argentina.
| | - Maria V Rossner
- Instituto Nacional de Tecnología Agropecuaria (INTA) E.E.A. El Colonia Benítez, Colonia Benítez, Chaco, Argentina
| | - Jose R Toffaletti
- Instituto Nacional de Tecnología Agropecuaria (INTA) E.E.A. El Colorado, El Colorado, Formosa, Argentina
| | - Miguel Da Luz
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Cerro Azul, Misiones, Argentina
| | - M Belen Rossner
- Universidad del Salvador, Facultad de Ciencias Agrarias y Veterinarias, Delegación Corrientes, Gobernador Virasoro, Corrientes, Argentina
| | - Marcelo Signorini
- IDICAL (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria (INTA) E.E.A. Rafaela, Ruta 34 Km 227, Rafaela, Santa Fe, Argentina
| | - Nicolás Morel
- IDICAL (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria (INTA) E.E.A. Rafaela, Ruta 34 Km 227, Rafaela, Santa Fe, Argentina
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Morel N, Torrents J, Nava S. Comparative analysis of Rhipicephalus microplus (Canestrini, 1888) infestation in pure breed (Hereford) and cross breed (Braford) cattle herds subjected to the same chemical treatments. EXPERIMENTAL & APPLIED ACAROLOGY 2024; 93:71-79. [PMID: 38811383 DOI: 10.1007/s10493-024-00922-7] [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: 11/29/2023] [Accepted: 05/01/2024] [Indexed: 05/31/2024]
Abstract
The aim of this work was to analyze the R. microplus (Canestrini, 1888) infestation in two bovine herds with different degrees of natural resistance (i.e., Hereford and Braford) to ticks subjected to an identical chemical treatment scheme to ticks at the same farm, to demonstrate the impact on tick control of the incorporation of a more resistant bovine breed. Two groups of ten Hereford and Braford cows each were subjected to eleven chemical treatments between August 2022 and October 2023 (four fluazuron, two fipronil 1%, one ivermectin 3.15% and four immersion in a dipping vat with a combination of cypermethrin 10% and ethion 40%). Tick population was shown to be susceptible to ivermectin, fluazuron and the mix cypermethrin 10%-ethion 40% and resistant to fipronil according to in vitro tests. Tick infestation was significantly greater in the Hereford cows than in the Braford cows. Tick infestation in both Hereford and Braford breeds was similar when treatment with functional drugs was applied, but when a block of the treatments was done with drugs with decreased functionality due to resistance (i.e. fipronil), treatment failure was manifested more strongly in the most susceptible breed. The incorporation of cattle breeds with moderate or high resistance to R. microplus is instrumental to optimize the efficacy and sustainability of chemical control of ticks in a scenario where resistance to one or more chemical groups is almost ubiquitous, because it favors the biological control of this parasite.
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Affiliation(s)
- Nicolas Morel
- Instituto de Investigación de La Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CC 22, CP 2300, Rafaela, Santa Fe, Argentina
| | - Jorgelina Torrents
- Instituto de Investigación de La Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CC 22, CP 2300, Rafaela, Santa Fe, Argentina
- Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Esperanza, Santa Fe, Argentina
| | - Santiago Nava
- Instituto de Investigación de La Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CC 22, CP 2300, Rafaela, Santa Fe, Argentina.
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Larsen K, Ichinose P, Fernández-San Juan R, Lifschitz A, Virkel G. Effects of acaricides on the activities of monooxygenases in bovine liver microsomes. J Vet Pharmacol Ther 2023; 46:375-384. [PMID: 37231529 DOI: 10.1111/jvp.13395] [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: 12/30/2022] [Revised: 05/04/2023] [Accepted: 05/07/2023] [Indexed: 05/27/2023]
Abstract
Organophosphates (OPs), pyrethrins and fipronil, are acaricides commonly used in cattle, mainly as pour on formulations. Scant information is available on their potential interactions with hepatic xenobiotic metabolizing enzymes. This work aimed to evaluate in vitro the potential inhibitory effects of widely employed acaricides on catalytic activities mediated by hepatic cytochrome P450 (CYP) and flavin-monooxygenase (FMO) enzymes in cattle. Bovine (n = 4) liver microsomes were incubated in the absence (control assays) and in presence of different OPs (fenthion, chlorpyrifos, ethion, diazinon and dichlorvos), fipronil and cypermethrin at 0.1-100 μm. Five oxidative enzyme activities were assayed by spectrofluorimetric or HPLC methods: 7-ethoxyresorufin O-deethylase (for CYP1A1), methoxyresorufin O-demethylase (for CYP1A2), benzyloxyresorufin O-debenzylase (for CYP2B), testosterone 6-beta hydroxylase (for CYP3A) and benzydamine N-oxidase (for FMO). All acaricides, particularly phosphorothionate-containing OPs, inhibited to some extent more than one enzyme activity. The most frequent inhibitor was fenthion, which inhibited (p < .05) all enzyme activities tested (from 22% at 1 μm to 72% at 100 μm). However, low inhibitory potencies (IC50s higher than 7 μm) of all acaricides studied were observed against the catalytic activities assayed. Therefore, the risk of in vivo metabolic interactions due to inhibition of monooxygenases would be low under common husbandry conditions.
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Affiliation(s)
- Karen Larsen
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Buenos Aires, Argentina
| | - Paula Ichinose
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Buenos Aires, Argentina
| | - Rocío Fernández-San Juan
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Buenos Aires, Argentina
| | - Adrián Lifschitz
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Buenos Aires, Argentina
| | - Guillermo Virkel
- Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Buenos Aires, Argentina
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Sarli M, Torrents J, Toffaletti JR, Morel N, Nava S. Evaluation of the impact of successive acaricide treatments on resistance evolution in Rhipicephalus microplus populations: Monodrugs versus drug combinations. Res Vet Sci 2023; 164:105040. [PMID: 37804667 DOI: 10.1016/j.rvsc.2023.105040] [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: 07/12/2023] [Revised: 08/28/2023] [Accepted: 09/22/2023] [Indexed: 10/09/2023]
Abstract
The aim of this work was to comparatively evaluate the evolution of resistance in Rhipicephalus microplus tick populations exposed to successive treatments with monodrug-based formulations and combinations of them in the same commercial formulation. Thirty-six heifers, naturally infested with R. microplus, were divided into three groups (G) and subjected to three successive treatments, on days 0 (Nov-2021), 43 (Jan-2022) and 78 (Feb-2022), with the following formulations: I) ivermectin 3.15% (Ivomec Gold®) (GI), II) fipronil 1% (Ectoline®) (GII) and III) a combination of fipronil 2% and ivermectin 1% (Vaquero®) (GIII). From Nov-2021 to Dec-2022, counts of R. microplus were periodically performed to evaluate the tick infestation. Engorged females were collected at the beginning and end of the trial to determine the evolution of tick resistance to ivermectin and fipronil by in vitro bioassays. At the end of trial, GII and GIII had higher tick counts (39.18 ± 11.88 and 38.33 ± 14.31, respectively) than group I (5.11 ± 6.24) (P<0.05). The in vitro results shows that the resistance ratio (RR50) values after the treatments were higher for fipronil (5.584 and 5.649 for GII and GIII, respectively) than for ivermectin (1.165 and 1.088 for GI and GIII, respectively). In the group treated with the combination (GIII), the RR50 increased for both drugs simultaneously. These results suggest that the successive use of drug combinations could exacerbate the problem of multi-resistance of R. microplus to chemical acaricides.
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Affiliation(s)
- Macarena Sarli
- Instituto de Investigación de la Cadena Láctea (IdICaL) (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), Ruta 34 Km 227, CP 2300 Rafaela, Santa Fe, Argentina.
| | - Jorgelina Torrents
- Instituto de Investigación de la Cadena Láctea (IdICaL) (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), Ruta 34 Km 227, CP 2300 Rafaela, Santa Fe, Argentina; Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Esperanza, Santa Fe, Argentina
| | - José R Toffaletti
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria El Colorado, El Colorado, Formosa, Argentina
| | - Nicolás Morel
- Instituto de Investigación de la Cadena Láctea (IdICaL) (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), Ruta 34 Km 227, CP 2300 Rafaela, Santa Fe, Argentina
| | - Santiago Nava
- Instituto de Investigación de la Cadena Láctea (IdICaL) (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), Ruta 34 Km 227, CP 2300 Rafaela, Santa Fe, Argentina
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Nicaretta JE, de Melo Junior RD, Naves RB, de Morais IML, Salvador VF, Leal LLLL, Teixeira ALC, Ferreira LL, Klafke GM, Monteiro CMDO, Borges FDA, Costa Junior LM, Rodrigues DS, Lopes WDZ. Selective versus strategic control against Rhipicephalus microplus in cattle: A comparative analysis of efficacy, animal health, productivity, cost, and resistance management. Vet Parasitol 2023; 321:109999. [PMID: 37556962 DOI: 10.1016/j.vetpar.2023.109999] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/11/2023]
Abstract
This study compared selective control versus strategic control against Rhipicephalus (Boophilus) microplus, under conditions of a real dairy farm. Strategic control requires that all animals be treated with acaricide at regular pre-determined intervals. Selective control only requires treatment of infested animals and only when they are at or above a pre-determined threshold. Tick counts on animals and in pasture were performed and the susceptibility of tick populations to the different treatment methods was evaluated at the beginning and end of the study using the Larval Packet Test, Larval Immersion Test, and Adult Immersion Test. Over the four years of the study strategic control was more advantageous than the selective control as the group experienced lower tick burden on animals and in pasture, absence of skin lesions and myiases, lower operating costs, treatments concentrated in fewer months of the year and lower resistance pressure.
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Affiliation(s)
- João Eduardo Nicaretta
- Escola de Veterinária e Zootecnia, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | | | - Raphaela Barbosa Naves
- Escola de Veterinária e Zootecnia, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | | | | | | | | | - Lorena Lopes Ferreira
- Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Guilherme Marcondes Klafke
- Instituto de Pesquisas Veterinárias Desidério Finamor - Centro de Pesquisa em Saúde Animal, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural, Eldorado do Sul, RS, Brazil
| | - Caio Marcio de Oliveira Monteiro
- Escola de Veterinária e Zootecnia, Universidade Federal de Goiás, Goiânia, Goiás, Brazil; Departamento de Biociências e Tecnologia, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Fernando de Almeida Borges
- Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal do Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | | | - Daniel Sobreira Rodrigues
- Empresa de Pesquisa Agropecuária de Minas Gerais, Campo Experimental Santa Rita, Prudente de Morais, Minas Gerais, Brazil
| | - Welber Daniel Zanetti Lopes
- Escola de Veterinária e Zootecnia, Universidade Federal de Goiás, Goiânia, Goiás, Brazil; Departamento de Biociências e Tecnologia, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
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Coate R, Alonso-Díaz MÁ, Martínez-Velázquez M, Castro-Saines E, Hernández-Ortiz R, Lagunes-Quintanilla R. Testing Efficacy of a Conserved Polypeptide from the Bm86 Protein against Rhipicephalus microplus in the Mexican Tropics. Vaccines (Basel) 2023; 11:1267. [PMID: 37515082 PMCID: PMC10383145 DOI: 10.3390/vaccines11071267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/18/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Rhipicephalus microplus economically impacts cattle production in tropical and subtropical countries. Application of acaricides constitutes the major control method; however, inadequate use has increased resistant tick populations, resulting in environmental and cattle product contamination. Anti-tick vaccines based on the Bm86 antigen are an environmentally friendly, safe, and economically sustainable alternative for controlling R. microplus infestations. Nevertheless, variable efficacy has been experienced against different geographic tick strains. Herein, we evaluated the efficacy of a conserved polypeptide Bm86 derived from a Mexican R. microplus strain previously characterized. Twelve cows were assigned to three experimental groups and immunized with three doses of the polypeptide Bm86 (pBm86), adjuvant/saline alone, and Bm86 antigen (control +), respectively. Specific IgG antibody levels were measured by ELISA and confirmed by Western blot. In addition, the reproductive performance of naturally infested R. microplus was also determined. The more affected parameter was the adult female tick number, with a reduction of 44% by the pBm86 compared to the controls (p < 0.05), showing a vaccine efficacy of 58%. Anti-pBm86 IgG antibodies were immunogenic and capable of recognizing the native Bm86 protein in the eggs, larvae, and guts of R. microplus. The negative correlation between antibody levels and the reduction of naturally tick-infested cattle suggested that the effect of the polypeptide Bm86 was attributed to the antibody response in immunized cattle. In conclusion, the polypeptide Bm86 showed a specific immune response in cattle and conferred protection against R. microplus in a Mexican tropical region. These findings support further experiments with this antigen to demonstrate its effectiveness as a regional vaccine.
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Affiliation(s)
- Raymundo Coate
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Ciudad de México 04510, Mexico
| | - Miguel Ángel 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 93600, Mexico
| | - Moisés Martínez-Velázquez
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C, Avenida Normalistas 800, Col. Colinas de la Normal, Guadalajara 44270, Mexico
| | - Edgar Castro-Saines
- Centro Nacional de Investigación Disciplinaria en Salud Animal e Inocuidad-INIFAP, Carretera Federal Cuernavaca-Cuautla 8534, Col. Progreso, Jiutepec 62550, Mexico
| | - Rubén Hernández-Ortiz
- Centro Nacional de Investigación Disciplinaria en Salud Animal e Inocuidad-INIFAP, Carretera Federal Cuernavaca-Cuautla 8534, Col. Progreso, Jiutepec 62550, Mexico
| | - Rodolfo Lagunes-Quintanilla
- Centro Nacional de Investigación Disciplinaria en Salud Animal e Inocuidad-INIFAP, Carretera Federal Cuernavaca-Cuautla 8534, Col. Progreso, Jiutepec 62550, Mexico
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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: 4] [Impact Index Per Article: 4.0] [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.
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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
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10
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Ferreira LC, Lima EF, Silva ALP, Feitosa TF, Klafke GM, Vilela VLR. Effect of cyclosporin A on the toxicity of ivermectin, eprinomectin and moxidectin in populations of Rhipicephalus microplus. Ticks Tick Borne Dis 2023; 14:102113. [PMID: 36565601 DOI: 10.1016/j.ttbdis.2022.102113] [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: 03/26/2022] [Revised: 11/26/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Rhipicephalus microplus is mainly controlled by acaricides. However, reports of resistance to acaricides including macrocyclic lactones (MLs) have become frequent worldwide. Involvement of ABC transporters (ABCts) in populations resistant to ivermectin has been demonstrated. Thus, the aim of this study was to evaluate the efficacy of ivermectin, eprinomectin and moxidectin with and without use of synergistic cyclosporin A (CsA) in resistant populations of R. microplus using larval immersion tests (LITs). Engorged females were collected from four farms in the semiarid region of northeastern Brazil that had histories of continuous use of ivermectin. Questionnaires were applied to collect information about management aimed at controlling ticks on these farms. Resistance to MLs was observed on all of the farms. There was statistically significant synergism (p < 0.05) between CsA and ivermectin in all populations; between CsA and eprinomectin in only one population; and between CsA and moxidectin in two populations. It was concluded that, despite the involvement of ABCts in the mechanisms of resistance to ivermectin, metabolic detoxification does not seem to be the mechanism predominantly involved in resistance to eprinomectin and moxidectin in the populations of R. microplus evaluated.
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Affiliation(s)
- Larissa Claudino Ferreira
- Programa de Pós-Graduação em Ciência e Saúde Animal, Universidade Federal de Campina Grande (UFCG). Avenida Universitária s/n. Patos, Paraíba, Brazil
| | - Estefany Ferreira Lima
- Departamento de Medicina Veterinária, Instituto Federal da Paraíba (IFPB), Avenida Presidente Tancredo Neves s/n. Sousa, Paraíba, Brazil
| | - Ana Luzia Peixoto Silva
- Departamento de Medicina Veterinária, Instituto Federal da Paraíba (IFPB), Avenida Presidente Tancredo Neves s/n. Sousa, Paraíba, Brazil
| | - Thais Ferreira Feitosa
- Departamento de Medicina Veterinária, Instituto Federal da Paraíba (IFPB), Avenida Presidente Tancredo Neves s/n. Sousa, Paraíba, Brazil
| | - Guilherme Marcondes Klafke
- Centro de Pesquisa em Saúde Animal (IPVDF), Secretaria da Agricultura, Pecuária e Desenvolvimento Rural. Estrada do Conde, 6000. Eldorado do Sul, Rio Grande do Sul, Brazil
| | - Vinícius Longo Ribeiro Vilela
- Programa de Pós-Graduação em Ciência e Saúde Animal, Universidade Federal de Campina Grande (UFCG). Avenida Universitária s/n. Patos, Paraíba, Brazil; Departamento de Medicina Veterinária, Instituto Federal da Paraíba (IFPB), Avenida Presidente Tancredo Neves s/n. Sousa, Paraíba, Brazil.
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11
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A comparison of two in vitro bioassays to detect resistance of the cattle tick Rhipicephalus microplus to fipronil. Vet Parasitol Reg Stud Reports 2023; 37:100816. [PMID: 36623897 DOI: 10.1016/j.vprsr.2022.100816] [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: 07/26/2022] [Revised: 10/25/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
The aim of this work is to compare the sensitivity of two in vitro bioassays to detect resistant to fipronil in Argentinean populations of the cattle tick Rhipicephalus microplus. Two different larval bioassays prepared with technical grade (97%) fipronil were compared: larval immersion test (LIT) and larval packet test (LPT). Seven strains from different provinces were treated with both assays. Colonia Tabay, Colonia Benítez, Intiyaco and Quimili strains were considered resistant in both LIT and LPT bioassays. The 95% confidence intervals (IC95) for lethal concentration 50% (LC50) did not overlap with the susceptible reference strain (SRS) and all the values of RR50 obtained were higher than 2. Garabato and Federal strains were considered as susceptible for both techniques because the IC95 for the LC50 overlapped with those of the SRS and the RR50 values were lesser than 2. An ambiguous situation occurs with Reconquista strain. This strain was considered as susceptible with LPT and with incipient resistant after LIT trial. The analysis of the results indicates that both LIT and LPT trials have enough sensibility to differentiate resistant and susceptible strains, but LIT was more sensitive than LPT when the resistance is incipient.
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12
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Torrents J, Sarli M, Sarmiento NF, Rossner MV, Morel N, Guglielmone AA, Nava S. Resistance of the cattle tick Rhipicephalus (Boophilus) microplus to fluazuron in Argentina. EXPERIMENTAL & APPLIED ACAROLOGY 2022; 86:599-606. [PMID: 35503589 DOI: 10.1007/s10493-022-00713-y] [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: 01/19/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
The aim of this work is to report the presence of resistance to fluazuron in a population of Rhipicephalus microplus in Argentina. The evidence was obtained from field and in vitro trials. In the field trial, cattle infested with ticks was treated with two commercial formulations of fluazuron. The in vitro trial (adult immersion test, AIT) was performed by using technical grade fluazuron. In the field trial, there were no significant differences between the treated and control groups between days 2 and 34 post-treatment. The only exceptions (treated group I in day 14 post-treatment, treated group II in days 23 and 29 post-treatment) had a significantly lower tick load than the untreated group, but the efficacy was not higher than 70%. Viable engorged females were collected on both groups of treated bovines in all counts, and the production of viable larvae was not precluded with the application of the two commercial formulations of fluazuron evaluated in this study. The results obtained with the in vitro assay (AIT) also indicate that the R. microplus population tested in this work has a higher level of resistance to fluazuron than another susceptible field strain. The integrated analysis of the field and in vitro trials clearly reveals the emergence of resistance to fluazuron in a R. microplus population from Argentina. This diagnosis of resistance does not imply that the fluazuron has lost its functionality at a regional scale, but it highlights the need to establish control strategies that minimize the use of this drug in order to preserve its functionality as an acaricide.
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Affiliation(s)
- Jorgelina Torrents
- Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Kreder 2805, 3080, Esperanza, Santa Fe, Argentina
| | - Macarena Sarli
- Instituto de Investigación de la Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CC 22, 2300, Rafaela, Santa Fe, Argentina
| | - Nestor F Sarmiento
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Mercedes (INTA E.E.A. Mercedes), Mercedes, Corrientes, Argentina
| | - Maria V Rossner
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Colonia Benítez (INTA E.E.A. Colonia Benítez), Colonia Benítez, Chaco, Argentina
| | - Nicolas Morel
- Instituto de Investigación de la Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CC 22, 2300, Rafaela, Santa Fe, Argentina
| | - Alberto A Guglielmone
- Instituto de Investigación de la Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CC 22, 2300, Rafaela, Santa Fe, Argentina
| | - Santiago Nava
- Instituto de Investigación de la Cadena Láctea (IDICAL, INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), CC 22, 2300, Rafaela, Santa Fe, Argentina.
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13
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Current status of resistance to ivermectin in Rhipicephalus sanguineus sensu stricto infesting dogs in three provinces in Argentina. Vet Parasitol Reg Stud Reports 2021; 26:100624. [PMID: 34879936 DOI: 10.1016/j.vprsr.2021.100624] [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: 05/03/2021] [Revised: 08/20/2021] [Accepted: 08/24/2021] [Indexed: 11/24/2022]
Abstract
Intensive use of macrocyclic lactones for parasite control exerts strong selective pressure for arthropods such as ticks to become resistant to them. Rhipicephalus sanguineus sensu stricto is a tick and disease vector of significant public health and veterinary importance worldwide. We assessed the toxicological response to the macrocyclic lactone ivermectin (IVM) in R. sanguineus s.s. infesting dogs in Argentina. Samples of nine tick populations were obtained by inspecting dogs at veterinary clinics, hospitals, or rural areas in the provinces of San Luis, Rio Negro, and Buenos Aires. Pet owners were interviewed to gather data on the history of dog treatment with ectoparasiticides. The larval immersion test was used to assess the toxicological response of R. sanguineus s.s. to IVM. Dose-response mortality regressions, lethal concentrations (LC), and slope were calculated by probit analysis. The lowest LC concentrations were used to designate the reference susceptible population because a laboratory reference strain of R. sanguineus s.s. does not exist in Argentina. Compared with the most susceptible tick population in this study, six populations (66.66%) were classified as resistant to IVM. A clear interpopulation variation in the level of IVM resistance was present (resistance ratios at LC50% ranged from 1.0 to 18.33 and at LC99% ranged from 1.0 to 8.96). In San Luis Province, all tick populations were classified as resistant. The highest level of IVM resistance (resistance ratio at LC50%:18.83 and LC99%:8.96) was found in a population of R. sanguineus s.s. from a rural area in the province of Buenos Aires. It is concluded that populations of R. sanguineus s.s. from dogs in three provinces of Argentina were resistant to IVM. Clear interpopulation variation in the level of IVM resistance was present.
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14
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Sarli M, Miró MV, Rossner MV, Nava S, Lifschitz A. Successive treatments with ivermectin (3.15%) to control the tick Rhipicephalus (Boophilus) microplus in cattle: Pharmacokinetic and efficacy assessment. Ticks Tick Borne Dis 2021; 13:101848. [PMID: 34656045 DOI: 10.1016/j.ttbdis.2021.101848] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/24/2021] [Accepted: 09/11/2021] [Indexed: 10/20/2022]
Abstract
This study aimed to evaluate the pharmacokinetics, the potential accumulation in the body of treated animals and the efficacy of ivermectin long-acting formulation (3.15%) against the cattle tick Rhipicephalus (Boophilus) microplus in a scheme of three successive treatments. Fifteen 12-month-old heifers, naturally infested with R. microplus, were divided into two groups (G). Cattle from GI (n = 10) were subjected to three treatments with ivermectin 3.15% (IVOMEC GOLD®, Merial Argentina S.A.) at a rate of 1 mL/50 kg on days 0, 35, and 70. Cattle from GII (n = 5) were not treated. From day 1 to 202 post-treatment blood samples were taken to measure ivermectin concentrations by HPLC and female ticks (4.5-8 mm) were counted to evaluate the efficacy of the treatment. The level of tick resistance to ivermectin was evaluated before and after finishing the scheme of successive treatments by larval immersion test (LIT) bioassay from engorged females collected from GI. The area under the concentration vs. time curves (AUC0-35d) obtained post-second treatment was 1.51 ± 0.39-fold higher than those observed post-first treatment (P<0.05). The mean plasma concentrations of ivermectin 3.15% at 20 days after the first, second and third treatment were 17.0, 27.5 and 37.8 ng/mL, respectively (P<0.01). The elimination half-life of ivermectin post-third treatment was significantly longer than that was previously reported after a single dose (P<0.01). Values of therapeutic efficacy percentage reached 75.6% post-first treatment and between 95.9 and 100% after the second treatment. Ticks evaluated by LIT showed a significant increase in lethal concentrations after treatments. Although the efficacy level was high, the successive treatments with long-acting ivermectin formulation generate a significant accumulation of drug in plasma and could increase the levels of resistance to this drug in the tick population.
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Affiliation(s)
- Macarena Sarli
- Instituto de Investigación de la Cadena Láctea (IdICaL) (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), Ruta 34 Km 227, CP 2300, Rafaela, Santa Fe, Argentina.
| | - María Victoria Miró
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET-CICPBA, Facultad de Ciencias Veterinarias, UNCPBA, CP 7000, Tandil, Prov. de Buenos Aires, Argentina
| | - María Victoria Rossner
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Colonia Benítez (INTA E.E.A. Colonia Benítez), Colonia Benítez, Chaco, Argentina
| | - Santiago Nava
- Instituto de Investigación de la Cadena Láctea (IdICaL) (INTA-CONICET), Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela (INTA E.E.A. Rafaela), Ruta 34 Km 227, CP 2300, Rafaela, Santa Fe, Argentina
| | - Adrián Lifschitz
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET-CICPBA, Facultad de Ciencias Veterinarias, UNCPBA, CP 7000, Tandil, Prov. de Buenos Aires, Argentina
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15
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Alternative applications of the strategic control against the cattle tick Rhipicephalus (Boophilus) microplus in a subtropical area. Parasitol Res 2021; 120:3653-3661. [PMID: 34561751 DOI: 10.1007/s00436-021-07324-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
Although different evaluations on the efficacy of the strategic control against Rhipicephalus microplus have been performed, the effects of successive applications of these schemes on the abundance of cattle ticks have not been evaluated. The aim of this work was to analyse the long-term effect of strategic applications of chemical acaricides on the R. microplus infestation in cattle in a subtropical area. These schemes are based on the application of three annual treatments between late winter and late spring. Additionally, a trial to evaluate the efficacy of the strategic control by deferring the first treatment from late winter to spring and the third treatment from late spring to summer was also carried out. The efficacy of the strategic control applied on 3 consecutive years was significant. The tick infestation in the treated group always remained at low levels, because mean number of ticks was almost never higher than 20. Regarding the trial where the third application of acaricide was deferred from spring to summer, and the first one from late winter to spring, the differences between treated and control group were significant in all post-treatment counts. The results of this study add evidence that support the sustainability of the strategic control in subtropical areas where the population dynamics of R. microplus is characterized by a well-marked seasonal pattern. Three relevant aspects were determined: (i) the feasibility and efficacy of successive applications of the strategic control in consecutive years; (ii) the time window to start the sequence of treatments is from late winter to mid-spring; (iii) it is achievable deferring the last treatment from late spring to summer if the tick infestation levels on cattle are low enough to allow it.
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16
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Torrents J, Morel N, Rossner MV, Martínez NC, Toffaletti JR, Nava S. In vitro diagnosis of resistance of the cattle tick Rhipicephalus (Boophilus) microplus to fipronil in Argentina. EXPERIMENTAL & APPLIED ACAROLOGY 2020; 82:397-403. [PMID: 33000337 DOI: 10.1007/s10493-020-00554-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
The aim of this work was to adapt and apply the in vitro larval bioassay packet test (LPT) to diagnose resistance of Rhipicephalus microplus ticks to fipronil in Argentina. Ten serial dilutions of fipronil were included in the LPT bioassay. Seven populations of R. microplus from six Argentinean Provinces were evaluated. Samples from Colonia Benítez, Quimilí and Intiyaco were unambiguously classified in the category 'resistant'. In all these cases the 95% confidence intervals did not overlap with that of the susceptible reference strain and the slope values were lower than the slope value obtained for the susceptible reference strain. The resistance ratio (RR50) values of the populations from Colonia Benítez I and II, Quimilí and Intiyaco were 2.23, 3.49, 6.84 and 3.39, respectively. Populations from El Colorado I and II, Acambuco, Vera and Feliciano were classified as 'susceptible' because the 95% confidence intervals overlapped with that of the susceptible reference strain and the RR50 values never exceeded 1.32. The results of these LPT bioassays indicate the presence of fipronil resistant R. microplus populations in Argentina.
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Affiliation(s)
- Jorgelina Torrents
- Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Kreder 2805, CP 3080, Esperanza, Santa Fe, Argentina
| | - Nicolás Morel
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela, CC 22, CP 2300, Rafaela, Santa Fe, Argentina
| | - Maria V Rossner
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Colonia Benítez, Colonia Benítez, Chaco, Argentina
| | - Norberto C Martínez
- Instituto Nacional de Tecnología Agropecuaria, Agencia de Extensión Rural Garabato, Garabato, Santa Fe, Argentina
| | - José R Toffaletti
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria El Colorado, El Colorado, Formosa, Argentina
| | - Santiago Nava
- Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela, CC 22, CP 2300, Rafaela, Santa Fe, Argentina.
- Consejo Nacional de Investigaciones Científicas y Técnicas (Conicet), Buenos Aires, Argentina.
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