Resistência anti-helmíntica de nematóides gastrintestinais em ovinos, Mato Grosso do Sul

Abstract

ABSTRACT.-Sczesny-Moraes E.A., Bianchin I., Silva K.F., Catto J. Among the methods of control of gastrointestinal worms in sheep, the use of chemicals is the most common. However, the continued, and indiscriminate, use of these products has selected populations of resistant helminths to anthelmintics, a phenomenon reported in the whole world. This study aimed to identify the species of gastrointestinal parasites and diagnose the status of anthelmintic resistance in sheep in the State of Mato Grosso do Sul Brazil. Feacal egg count reduction tests (FECRT) were performed in flocks of sixteen farms, and the seven formulations used contained the following pharmacological bases: Albendazole, Ivermectin, Levamizol, Trichlorfon, Moxidectin, Closantel and one containing the first three in association. The species identified at necropsy, in adult sheep, were: Haemonchus contortus, Trichostrongylus colubriformis, Cooperia curticei, C. punctata, C. pectinata and Oesophagostomum columbianum, in order of prevalence. The formulations containing Albendazole and Ivermectin did not show efficacy in reducing the EPG in the flocks tested, with average reductions of 0.7 and -19.6%, respectively. Closantel presented an average efficacy of 6.7%; Levamisolee, Moxidectin and Trichlorfon, 28.7, 26.8 and 65% respectively, the combination of three bases (Albendazole, Ivermectin and Levamizol), an average efficacy of 55.8 %. The average percentages of infective larvae recovered in the faecal cultures, pre and post treatment were similar, indicating that resistance to the bases tested is present in all species cited, to a greater or lesser degree. The two genera predominantly resistant are Haemonchus sp., with 86.9%, followed by Trichostrongylus sp., with an average of 47.5%, Strongyloides sp. 33.6%, Oesophagostomum sp.

Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control

“…With regard to the efficacy noted with the drugs administered individually or in combination, the results of this study corroborate those presented by Sczesny-Moraes et al (2010), but contradict those reported by Soccol et al (2004), Buzzulini et al (2007), Cezar et al (2010), and Holsback et al (2013), all of which found higher efficacies with the administration of drug combinations compared to those obtained with individual drugs.…”

“…The various mechanisms of resistance include modifying the action of the target molecule, increasing the number of targets receptors, increasing the rate of drug excretion, increasing the metabolism of the active ingredient, or simply, drug sequestration (KELLY & HALL 1979;TORRES-ACOSTA & HOSTE, 2008). A large variation in the degree of resistance of various nematode populations against anthelmintics have been widely reported the world over for several decades (JACKSON, 1993;MELO et al, 2003;COLES, 2005;BORGES et al, 2008;CONDI et al, 2009;SCZESNY-MORAES et al, 2010).…”

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

“…As can be seen in Table 2, this anthelmintic showed the highest effectiveness rate (stand-alone) in five studies involving sheep (CUNHA et al, 1998;THOMAZ-SOCCOL et al, 2004;CEZAR et al, 2010;LIMA et al, 2010b;SCZESNY-MORAES et al, 2010) and in three studies involving goats (AHID et al, 2007; RODRIGUES et al, 2007; LIMA et al, 2010b). Although its mechanism of action is similar to that of ivermectin, several authors around the world have observed the greater effectiveness of moxidectin in strains resistant to ivermectin (BARNES et al, 2001;VICKERS et al, 2001;LLOBERAS et al, 2013).…”

“…The state of Mato Grosso do Sul (MS) has one article published in the area, and shows a great potential for growth in the sheep industry, especially as it is located close to the large consumer market in the state of São Paulo. In this state, Sczesny-Moraes et al (2010) evaluated the effectiveness of albendazole, ivermectin, levamisole, trichloform, moxidectin, closantel, and a combination of the first three drugs. On 16 sheep farms.…”

Resistência À Verminose E Suplementação Proteica No Periparto: Efeito No Parasitismo E No Desempenho Reprodutivo De Ovelhas Do Grupamento Racial Pantaneiro

“…No Mato Grosso do Sul, a verminose também é percebida como a principal doença, agravada pela disseminação da resistência dos parasitas aos anti-helmínticos (3) .…”