Tick and tick borne diseases cause many problems to the cattle industry worldwide. The prevalence of resistant strains of Rhipicephalus microplus to different acaricides on cattle farms in the tropical region of Tecpan of Galeana, Guerrero, Mexico, and risk factors related to prevalence of resistant strains of R. microplus. Sixty one ranches infested were sampled; in each ranch were collected 30-50 fully-engorged female R. microplus ticks, of 10 cattle randomly selected, and evaluated in their progeny resistance to acaricides, using the larval packet test. The prevalence of resistant strains was total pyrethroids and amitraz. In organophosphorus 31.1, 48.3 and 82.2% of strains were resistant to clorpyriphos, coumaphos and diazinon, respectively. Risk factors favored (P<0.05) the development of resistant strains of acaricides. We concluded that the resistance of R. microplus to acaricides used to control a problem, and risk factors (livestock management) have accelerated the development of resistance

J. Olivares-Pérez*, S. Rojas-Hernández, M.T. Valencia-Almazan, I. Gutiérrez-Segura and E.J. Míreles-Martínez

Directory of Open Access Journals

366  Pakistan Veterinary Journal ISSN: 0253-8318 (PRINT), 2074-7764 (ONLINE) Accessible at: www.pvj.com.pk    Prevalence of Resistant Strains of Rhipicephalus microplus to Acaricides in Cattle Ranch in the Tropical Region of Tecpan of Galeana, Guerrero, Mexico  J. Olivares-Pérez*, S. Rojas-Hernández, M.T. Valencia-Almazan, I. Gutiérrez-Segura and E.J. Míreles-Martínez  Faculty of Veterinary Medicine, University Autonomous of Guerrero, km. 3.0 carr. Nal. Altam.-Iguala.  Cd. Altamirano, Gro., Mexico CP 40660. Tel/fax: 767 67 23494. *Corresponding author: olivaares@hotmail.com   ARTICLE HISTORY     ABSTRACT  Received: Revised: Accepted: March 18, 2011 April 18, 2011  April 20, 2011  Key words:  Acaricides Resistance Rhipicephalus microplus    Tick and tick borne diseases cause many problems to the cattle industry worldwide. The prevalence of resistant strains of Rhipicephalus microplus to different acaricides on cattle farms in the tropical region of Tecpan of Galeana, Guerrero, Mexico, and risk factors related to prevalence of resistant strains of R. microplus. Sixty one ranches infested were sampled; in each ranch were collected 30-50 fully-engorged female R. microplus ticks, of 10 cattle randomly selected, and evaluated in their progeny resistance to acaricides, using the larval packet test. The prevalence of resistant strains was total pyrethroids and amitraz. In organophosphorus 31.1, 48.3 and 82.2% of strains were resistant to clorpyriphos, coumaphos and diazinon, respectively. Risk factors favored (P<0.05) the development of resistant strains of acaricides. We concluded that the resistance of R. microplus to acaricides used to control a problem, and risk factors (livestock management) have accelerated the development of resistance.  ©2011 PVJ. All rights reserved To Cite This Article: Olivares-Pérez J, S Rojas-Hernández, MT Valencia-Almazan, I Gutiérrez-Segura and EJ Míreles-Martínez,  2011. Prevalence of resistant strains of Rhipicephalus microplus to acaricides in cattle ranch in the tropical region of tecpan of galeana, Guerrero, Mexico. Pak Vet J, 31(4): 366-368.  INTRODUCTION  There are approximately 899 known species of ticks (Barker and Murrell, 2004). About 10% of these species are established in Mexico. Of the identified 77 species of ticks, five genera of the Family Argasidae and seven in the Ixodidae have great importance for cattle (Akhtar et al., 2011). In Mexico and other tropical and subtropical regions, the most economically important ticks in cattle are R. microplus and R. annulatus, which are vector of Babesia bigemina and Babesia bovis (Rosario-Cruz et al., 2009). In areas with incidence of Rhipicephalus spp. actions are taken to control through strategic and selective treatments, depending on the time of the year, the parasite load per animal (infestation) and the percentage of animals infested by the ectoparasites (Irshad et al., 2010). The use of chemical control has exerted pressure in recent years for the selection of strains of R. microplus resistant (Rosario-Cruz  et al., 2009). The objective of the study was to determine the prevalence of resistant strains of R. microplus to pyrethroids, amidines and organophosphorus in cattle ranches, using the larval packet technique and risk factors associated with the development of resistance in the tropical region of Tecpan of Galeana, Guerrero, Mexico. MATERIALS AND METHODS  The municipality of Tecpan of Galeana is located 120 meters above the sea level, southwest of Chilpancingo, between parallels 17° 07' and 17° 42' north latitude and 100° 28' and 101° 06' west on Greenwich Meridian. Bordered on the north Coyuca Catalan and Ajuchitlán Progress on the east by Atoyac of Alvarez and Benito Juarez, on the south by the Pacific Ocean and west Petatlán. The samples were obtained from the total population of cattle ranch (n=60) affiliated with the local livestock association Tecpan of Galeana, Guerrero, Mexico. Collection of 3-5 full-engorged females of R. microplus were made from 10 randomly selected cattle (Cabrera-Jimenez et al., 2008). These were placed in small bottles drilled in the top to allow air circulation and provided a humid environment (cotton swab moistened with water). The samples were transported to the Parasitology Laboratory of the National Center for Animal Health Verification (CENAPA) in Jiutepec, Mor. Mexico; where acaricides resistance work (samples in triplicate) by the larval packet test (LPT) developed by Stone and Haydock (1962) was performed. Engorged ticks were placed in petri dishes and incubated in obscurity at a temperature of SHORT COMMUNICATION Pak Vet J, 2011, 31(4): 366-368.  36727±2°C and relative humidity (RH) of 80-90% to allow for oviposition. The eggs were placed in glass vials plugged with cotton under the same conditions of temperature and humidity to which the full ticks were to allow the eclosion of larvae. The diagnosis of resistance was established by discriminating dose reference susceptible strains, which were to pyrethroids: cypermethrin (0.05%), deltamethrin (0.09%), flumethrin (0.01%); amidines: amitraz (0.0002%) (Stone and Haydock, 1962) and organophos- phorus: clorpyriphos (0.02%), coumaphos (0.02%), diazinon (0.08%) (Shaw, 1966). Readings were taken at 24 h after treatment and was seen as discriminating dose twice the concentration of acaricide that kills 99.9% of the population of susceptible ticks (Cabrera-Jimenez et al., 2008; Villarroel-Alvarez et al., 2006). Mortality percentage of larvae was calculated as:  Larval mortality (%) = Dead larvae/total larvae (100)  To relate the risk factors for ticks resistant, a survey of livestock farmer’s included data on the frequency of dips for tick control, frequency of rotation chemical products, type and/or manner and/or dosage of the product, which produces cattle breeds and types of grasslands that are at his ranch. The prevalence was calculated using the following formula (Villarroel-Alvarez et al., 2006):  Prevalence % = No. of ranches with acaricides resistant ticks/No. total ranches sampled (100)   The significant influence of risk factors (independent variables) such as the rotation frequency of chemical formula used for tick control, product application form, the breed as a genetic factor and type of existing pastures on ranch about the prevalence of resistant ticks was analyzed by Chi square 2x2 contingency tables and the genetic factor of 3x2, with an alpha of P<0.05 (SAS, 2002).  RESULTS AND DISCUSSION  Total resistance was observed in ticks R. microplus, to amidines (amitraz, with larval mortality between 13.4-82.7%) and pyrethroids (flumethrin, deltamethrin and cypermethrin with larval mortality between 0-89.6, 7.8-91.8 and 11.5-91.3%, respectively). In organophosphorus, resistance was observed with 31.1, 48.3 and 82.2% to clorpyriphos, coumaphos and diazinon, with larval mortality   between  36.7-100,  25.3-100  and  18.6-100%,  respectively (Table 1). There are many records about the ability of parasites to develop resistance to   chemicals products used for its control in ruminants (Alonso-Diaz et al., 2006). Rodriguez-Vivas et al. (2005) and Rosario-Cruz et al. (2009) reported resistant strains R. microplus to acaricides in Mexico. Table 2 showed that on ranch that took between 3 and 4 years in rotating the acaricide used to control R. microplus, favored the highest prevalence (P=0.008) of resistant strains (49.1%), the practice of not rotate more frequently the product is due to the failure of technical assistance to livestock farmers, this favored the flourishing of resistant ticks (Rodriguez-Vivas et al., 2005). Alonso-Diaz et al. (2006) reported that the product rotation delays the development of resistance. Livestock farmers who rotated the product between 3 and 4 years showed that the change of the product is due to the inefficiency observed for tick control. Villarroel-Alvarez et al. (2006) and George et al. (2004) reported that when the product fails to change, or can increase the concentration and frequency of the baths, practices that favoring the development of resistance in ticks.  On ranches acaricide products were tested by two ways of applying, i.e., the spray (52.5%) and pour-on (47.5%), of these, spray application favored (P=0.007) higher prevalence of strains of R. microplus resistant (Table 2). This could be due to that livestock farmers in preparing the solution presumptively dosed and used an average of 2 liters of solution prepared by spraying adult animal, an amount which according to George et al. (2004) does not guarantee deep moisturizing body surface of the animal as 4-8 liters are required solution per adult animal. It has been observed that genetic composition of herds significantly (P<0.038) influenced the prevalence of resistant strains of R. microplus; as these were high in Holstein cattle ranches (37.7%) followed in Swiss cattle ranches and Swiss-Zebu hybrid ranches (Table 2). This indicates that European breeds are more susceptible to infestations by ectoparasites, which increases frequency of application of chemicals to control and therefore the selection pressure tick strains resistant to the formula (Rodriguez-Vivas et al., 2005; Alonso-Diaz et al., 2006). We conclude that the resistance of R. microplus to acaricides is a problem that placed the chemical control method at a disadvantage to the evolution of ectoparasite; also risk factors related to the management & application of chemicals product and breeds that produced, has favored the development of resistance in ticks.  Table 1: Larval mortality and prevalence of strains of R. microplus resistance to acaricides used as chemical control in cattle ranches Tecpan of Galeana, Gro. Mexico. Larval mortality  Ranches ranges   Positives  Negatives*  Acaricide group  Active substance (%) No.  %  No.  % Clorpyriphos  36.7-100  19  31.1 42 68.8 Coumaphos  25.3-100  29  48.3 31 55.6 Organophosphorus Diazinon  18.6-100  51  82.2 11 17.7 Flumethrin   0-89.6 61  100  0  0 Deltamethrin   7.8-91.8 61  100  0  0 Pyrethroids Cypermethrin   11.5-91.3 61  100  0  0 Amidines Amitraz  13.4-82.7 61  100  0  0 * Samples of ranches with 100% larval mortality, larval packet tests. Pak Vet J, 2011, 31(4): 366-368.  368Table 2: Risk factors and R. microplus resistance to acaricides in cattle ranches in the municipality of Tecpan of Galeana, Gro. Mexico Risk factors  Positive ranches Product rotation time*  No.  %  P value 1 to 2 years  25  40.9  0.008 3 to 4 years  30  49.1   Application form       Sprayed   29  47.5  0.007 Pour-on 18  29.5   Breed      Swiss-Zebu 12  19.6  0.038 Swiss 17  27.8   Holstein 23  37.7   Grassland type       Temporal 14  22.9  0.741 Temporal and irrigation  35  57.3   *Consecutive years of using the same product for tick control  REFERENCES  Akhtar M, F Muhammad, LA Lodhi, I Hussain and MI Anwar, 2011. Immunity against ticks-A review. Pak Vet J, 31: 9-16. Alonso-Díaz MA, RI Rodríguez-Vivas, H Fragoso-Sánchez and R Rosario-Cruz, 2006. Ixodicide resistance of the the Boophilus microplus tick to ixodicides. Arch Med Vet, 38: 105-114. Barker SC and A Murrell, 2004. Systemactics and evolution of ticks with a list of valid genus and species names. Parasitology, 129: S15-36. Cabrera-Jiménez D, RI Rodríguez-Vivas and JA Rosado-Aguilar, 2008. Evaluation of cypermethrin resistance in Boophilus microplus strains from cattle farms in the state of Yucatán, Mexico. Tec Pecu Méx, 46: 439-448. George JE, JM Pound and RB Davey, 2004. Chemical control of ticks on cattle and the resistance of these parasites to acaricides. Parasitology, 129: S353–366. Irshad N, M Qayyum, M Hussain and MQ Khan, 2010. Prevalence of tick infestation and theileriosis in sheep and goats. Pak Vet J, 30: 178-180. Rodríguez-Vivas RI, MA Alonso-Díaz, F Rodríguez-Arévalo, H Fragoso-Sánchez, VM Santamaría and R Rosario-Cruz, 2005. Prevalence and potential risk factors for organophosphates and pyrethroids resistance in Boophilus microplus ticks in cattle ranches from the State of Yucatan, Mexico. Vet Parasitol, 136: 335-342. Rosario-Cruz R, FD Guerrero, RJ Miller, RI Rodríguez-Vivas, M Tijerina, DI Domínguez-García, R Hernández-Ortiz, AJ Cornel, RD McAbee and MA Alonso-Díaz, 2009. Molecular survey of pyrethroid resistance mechanisms in Mexican field populations of  Rhipicephalus ( Boophilus)  microplus. Parasitol Res, 105: 1145–1153. Shaw RD, 1966. Culture and organophosphorus resistant strain of B. microplus (Can.) and an assessment of its resistance spectrum. Bull Entomol Res, 56: 389-405. Statistical Analysis System (SAS). 2002. SAS/STAT. In: Guide for Personal Computers Version Ver 9.0. Institute Inc. Cary, NC, USA; pp: 956. Stone BF and P Haydock, 1968. A method for measuring the acaricide susceptibility of de cattle Boophilus microplus. Bull Entomol Res, 53: 563-578. Villarroel-Alvarez M, RI Rodríguez-Vivas, F Villegas-Anze, H Fragoso-Sánchez, A Ortiz-Nájera and S Neri-Orantes, 2006. Prevalence and potential risk factors for pyrethroids resistance in Boophilus microplus ticks on milk farms in Santa Cruz Department, Bolivia. Tec Pec Méx, 44: 155-167.  

Prevalence of Resistant Strains of Rhipicephalus microplus to Acaricides in Cattle Ranch in the Tropical Region of Tecpan of Galeana, Guerrero, Mexico

Abstract

Similar works

Full text

Available Versions

Directory of Open Access Journals