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Anjos OO, Gomes MN, Tavares CP, Sousa DM, Mendonça CJS, Reck J, Maciel AP, Costa-Junior LM. Polymeric films of corn starch enhance the lethal effects of thymol and carvacrol terpenes upon Rhipicephalus microplus ticks. Vet Parasitol 2024; 327:110149. [PMID: 38412588 DOI: 10.1016/j.vetpar.2024.110149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/17/2024] [Accepted: 02/17/2024] [Indexed: 02/29/2024]
Abstract
The tick Rhipicephalus microplus is a parasite of great importance in cattle breeding. It is responsible for huge economic losses. The application of synthetic acaricides is used as a form of control. However, resistant strains have been selected over the years, making it necessary to search for new alternative formulations. The present study aimed to formulate biodegradable films impregnated with the terpenes carvacrol and thymol and evaluate their efficacy on larvae and adults of R. microplus through in vitro tests. The following formulations were prepared: Film 1 (starch based); Film 2 (based on starch and glycerol); Film 1 + Carvarcol or Thymol; Film 2 + Carvarcol or Thymol. Terpenes had a final concentration of 5.0 mg/mL. To evaluate the formulations on larvae, the immersion test was performed by dividing into six groups according to the concentration of terpenes: 5.0, 2.5, 1.25, 0.625, 0.313, 0.156 mg/mL and the control groups: 1% ethanol solution; 10% ethanol solution; Film 1; and Film 2. For the evaluations on adult ticks, ten experimental groups (n = 10) were used: 1) Carvacrol; 2) Film 1 + Carvacrol; 3) Film 2 + Carvacrol; 4) Thymol; 5) Film 1 + Thymol; 6) Film 2 + Thymol; 7) Distilled water; 8) 10% ethanol solution; 9) Film 1; and 10) Film 2. In experimental groups 1-6, carvacrol and thymol (free or incorporated in two different biodegradable film formulations) were evaluated at the same concentration (5.0 mg/mL). Each group of ticks was immersed in their respective solutions for five minutes. The results of the tests on larvae showed that the Film 1 + thymol and Film 2 + carvacrol formulations had the lowest lethal concentrations (0.076 and 0.255 mg/mL, respectively), values up to 9.0-fold lower than the monoterpenes tested outside the formulation. Carvacrol and thymol at the concentrations tested were effective in controlling engorged females with a percentage of 32.2% and 63.8%, respectively. When incorporated into biodegradable film formulations, these monoterpenes showed much greater efficacy. Film 1 + carvacrol and Film 2 + carvacrol with control percentages of 71.6% and 97.2%, respectively, while the formulations Film 1 + thymol and Film 2 + thymol showed values of 96.9% and 100.0%. The tick control activity of the biopolymer formulations with thymol and carvacrol was demonstrated through the high mortality rates of larvae and engorged females of the tick R. microplus. Therefore, the results obtained indicate that these formulations have great potential for tick control mainly because of the percentage of control up to 100% in engorged females in in vitro tests.
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Affiliation(s)
- Olga O Anjos
- Parasite Control Laboratory, Federal University of Maranhão - UFMA, São Luís, MA, Brazil; Fuel, Catalysis and Environmental Center, Federal University of Maranhão - UFMA, São Luís, MA, Brazil
| | - Matheus N Gomes
- Parasite Control Laboratory, Federal University of Maranhão - UFMA, São Luís, MA, Brazil
| | - Caio P Tavares
- Parasite Control Laboratory, Federal University of Maranhão - UFMA, São Luís, MA, Brazil
| | - Dauana M Sousa
- Parasite Control Laboratory, Federal University of Maranhão - UFMA, São Luís, MA, Brazil
| | | | - José Reck
- Instituto de Pesquisas Veterinárias Desidério Finamor (IPVDF), Eldorado do Sul, RS, Brazil
| | - Adeilton P Maciel
- Fuel, Catalysis and Environmental Center, Federal University of Maranhão - UFMA, São Luís, MA, Brazil
| | - Livio M Costa-Junior
- Parasite Control Laboratory, Federal University of Maranhão - UFMA, São Luís, MA, Brazil.
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Sales DP, Silva-Junior MHS, Tavares CP, Sousa IC, Sousa DM, Brito DRB, Camargo AM, Leite RC, Faccini JLH, Lopes WDZ, Labruna MB, Luz HR, Costa-Junior LM. Biology of the non-parasitic phase of the cattle tick Rhipicephalus (Boophilus) microplus in an area of Amazon influence. Parasit Vectors 2024; 17:129. [PMID: 38486221 PMCID: PMC10938741 DOI: 10.1186/s13071-024-06220-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 02/28/2024] [Indexed: 03/18/2024] Open
Abstract
BACKGROUND Rhipicephalus (Boophilus) microplus is the most important tick species affecting cattle in the world. Under field conditions, the non-parasitic phase of R. (B.) microplus is unknown in the Amazon biome, including Brazil. The present study aimed to evaluate the non-parasitic phase of R. (B.) microplus in field (grass plots) and laboratory conditions. METHODS The study was conducted from September 2020 to April 2022 in an Amazonian region (Maranhão State, Brazil). We evaluated the biological parameters of R. (B.) microplus under laboratory and field conditions. Engorged females were exposed to experimental conditions every 14 days, totaling 20 months of study. The following biological parameters were observed: pre-oviposition period, egg mass incubation period, and maximum larval survival period. RESULTS Abiotic data (e.g., temperature and humidity) varied little throughout the year. Precipitation was the factor that varied the most throughout the year (dry ~ 30 mm3 and rain 400 mm3), and the parameters of pre-oviposition and pre-hatching are longer during the rainy season. A possible negative effect of the dry season on the percentage of hatched eggs was observed. Larval longevity in the plots of both control and free females was short (mean ~ 50-60 days), below that recorded for larvae under controlled conditions (mean ~ 95 days). CONCLUSIONS Rhipicephalus (Boophilus) microplus was able to complete its non-parasitic phase by producing host-seeking larvae in the pasture during all months of the study. The results indicate that R. (B.) microplus can complete up to six generations per year in biome Amazon. To our knowledge, this is the highest number of annual generations for R. (B.) microplus in Latin America.
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Affiliation(s)
- Daniela P Sales
- Post-Graduation Program in Animal Health Defense, State University of Maranhão, Maranhão, Brazil
| | | | - Caio P Tavares
- Laboratory of Parasite Control, Federal University of Maranhão, São Luís, Maranhão, Brazil
| | - Isabella C Sousa
- Laboratory of Parasite Control, Federal University of Maranhão, São Luís, Maranhão, Brazil
| | - Dauana M Sousa
- Laboratory of Parasite Control, Federal University of Maranhão, São Luís, Maranhão, Brazil
| | - Danilo R B Brito
- Federal Institute of Education, Science and Technology of Maranhão, São Luís, Maranhão, Brazil
| | - André M Camargo
- Federal Institute of Education, Science and Technology of Maranhão, São Luís, Maranhão, Brazil
| | - Romário Cerqueira Leite
- Post-Graduation Program in Animal Health Defense, State University of Maranhão, Maranhão, Brazil
| | - J L H Faccini
- Post‑Graduation Program in Health Sciences, Center of Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil
| | - Welber D Z Lopes
- School of Veterinary and Zootechny of the Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Marcelo B Labruna
- Department of Preventive Veterinary Medicine and Animal Health, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Hermes R Luz
- Laboratory of Parasite Control, Federal University of Maranhão, São Luís, Maranhão, Brazil.
- Post‑Graduation Program in Northeast Biotechnology Network (RENORBIO), Biodiversity and Conservation, Center of Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil.
| | - Livio M Costa-Junior
- Laboratory of Parasite Control, Federal University of Maranhão, São Luís, Maranhão, Brazil
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Santos IS, Tavares CP, Klafke GM, Reck J, Monteiro CMO, Prata MCA, Golo PS, Silva AC, Costa-Junior LM. Automatic method based on deep learning to identify and account Rhipicephalus microplus larval hatching. Med Vet Entomol 2023; 37:665-674. [PMID: 37183718 DOI: 10.1111/mve.12664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 04/26/2023] [Indexed: 05/16/2023]
Abstract
Reports of Rhipicephalus microplus resistant populations worldwide have increased extensively, making it difficult to control this ectoparasite. The adult immersion test, commonly used to screen for acaricide resistance, produces the results only after 40 days of the tick collection because it needs the eggs to be laid and larvae to hatch. The present study aims to develop an automatic method, based on deep learning, to predict the hatching of R. microplus larva based on egg morphology. Initially, the time course of embryonic development of tick eggs was performed to discriminate between viable and non-viable eggs. Secondly, using artificial intelligence deep learning techniques, a method was developed to classify and count the eggs. The larval hatching rate of three populations of R. microplus was evaluated for the software validation process. Groups of three and six images of eggs with 12 days of embryonic development were submitted to the software to predict the larval hatching percent automatically. The results obtained by the software were compared with the prediction results of the hatching percentage performed manually by the specialist and with the results of the hatching percentage of larvae obtained in the biological assay. The group with three images of each population submitted to the software for automatic prediction of the larval hatching percent presented mean values of 96.35% ± 3.33 (Piracanjuba population), 95.98% ± 3.5 (Desterro population) and 0.0% ± 0.0 (Barbalha population). For groups with six images, the values were 94.41% ± 3.84 (Piracanjuba population), 95.93% ± 2.36 (Desterro population) and 0.0% ± 0.0 (Barbalha population). Biological assays showed the following hatching percentage values: 98% ± 1.73 (Piracanjuba population); 96% ± 2.1 (Desterro population); and 0.14% ± 0.25 (Barbalha population). There was no statistical difference between the evaluated methods. The automatic method for predicting the hatching percentage of R. microplus larvae was validated and proved to be effective, with considerable reduction in time to obtain results.
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Affiliation(s)
- Igor S Santos
- Applied Computing Core, Federal University of Maranhão - UFMA, São Luís, Brazil
| | - Caio P Tavares
- Parasite Control Laboratory, Federal University of Maranhão - UFMA, São Luís, Brazil
| | - Guilherme M Klafke
- Instituto de Pesquisas Veterinárias Desidério Finamor (IPVDF) - Centro de Pesquisa em Saúde Animal, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural, Eldorado do Sul, Brazil
| | - José Reck
- Instituto de Pesquisas Veterinárias Desidério Finamor (IPVDF) - Centro de Pesquisa em Saúde Animal, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural, Eldorado do Sul, Brazil
| | - Caio M O Monteiro
- Departamento de Biociências e Tecnologia do Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, Brazil
| | | | - Patrícia S Golo
- Departamento de Parasitologia Animal, Universidade Federal Rural do Rio de Janeiro, Seropédica, Brazil
| | - Aristófanes C Silva
- Applied Computing Core, Federal University of Maranhão - UFMA, São Luís, Brazil
| | - Livio M Costa-Junior
- Parasite Control Laboratory, Federal University of Maranhão - UFMA, São Luís, Brazil
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Tavares CP, Sabadin GA, Sousa IC, Gomes MN, Soares AM, Monteiro CM, Vaz IS, Costa-Junior LM. Effects of carvacrol and thymol on the antioxidant and detoxifying enzymes of Rhipicephalus microplus (Acari: Ixodidae). Ticks Tick Borne Dis 2022; 13:101929. [DOI: 10.1016/j.ttbdis.2022.101929] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 12/27/2022]
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