Cyathostomin nematode: evaluation of the development of eggs at low temperatures and the effect of plant extracts on the pre-parasitic

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2020-07-28T17:51:57Z No. of bitstreams: 1 2011 - Luciene Soares de Souza.pdf: 1626887 bytes, checksum: 60cd70513d5290267cf2ef8c4ba9ba27 (MD5) Made available in DSpace on 2020-07-28T17:51:58Z (GMT). No. of bitstreams: 1 2011 - Luciene Soares de Souza.pdf: 1626887 bytes, checksum: 60cd70513d5290267cf2ef8c4ba9ba27 (MD5) Previous issue date: 2011-02-24 Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil. The cyathostomin (Cyathostominae) are the most abundant nematodes in the large intestine of horses. Due to problems with increasing parasite resistance to anthelmintics has been growing concern about the effect of medicinal plants in order to find new and alternative methods to control the prevalence and severity of infections cyathostomin. The effect of temperature on egg development of cyathostomin and storage time of the stool are poorly studied, and this is the first study performed in vitro under storage conditions at low temperatures. The aim of this study was evaluated the development of eggs recovered from faeces, kept under different temperatures and test the effect of plant extracts on the eggs, first stage larvae (L1) and infective larvae (L3) cyathostomin, divided into two chapters. The first chapter deals with the evaluation of the influence of low temperatures on egg development until the first larval stage (L1) and third larval stage (L3), divided into four experiments with changes in the methodology. For the execution of experiments, feces were collected directly from horses not dewormed. Later they were made to count eggs per gram (EPG) to estimate the parasite load of each donor animal and stool cultures for identification of L3. The total mass was homogenized and samples were kept undisclosed stored under different temperatures: refrigeration (?10?C) and congelation (-4?C) during the duration of each experiment. Weekly or fortnightly, depending on the methodology used in the experiment, eggs (?300) were recovered and kept in petri dishes at room temperature (?25?C) and observed under an optical microscope (40x) after 24 hours to count the different stages of development of the egg to L1. The L3 were retrieved via coproculture. But the chapter 2 evaluates the effect of aqueous extract of two plants, Solanum lycocarpum and Curatella americana both from Three Marias- MG, on cyathostomin eggs, L1 and L3. Eggs (?400) were recovered from fresh fecal mass, the L1 (?400) after 24 hours of developing eggs, and L3 using the coproculture. The experiments were conducted separately to assess the percentual of inhibition development eggs (% IDO) and the percentual of reduction larval motility (%RML) by the action of extracts in the concentrations of 5, 2,5 and 1% during 24h. This was the first study performed with assessment and observation of developing eggs cyathostomin at low temperatures during the seasons. The studies presented in chapter I observed variation in egg development until the L3 stage in different seasons, in samples kept under ?10?C and -4?C. In Chapter II, it was observed that the aqueous extracts of the plants showed better evaluated larvicidal effect on L1 and had no effect on the eggs ovicidal cyathostomin. It follows that the congelation temperature of the eggs not killed; faecal masses can be stored for a period of 30 days for diagnosis and further studies must be performed in vitro with aqueous extracts of Solanum lycocarpum and Curatella american to verify the potential anthelmintic in other concentrations. Os ciatostom?neos (Cyathostominae) s?o os nemat?ides mais abundantes no intestino grosso dos equinos. Devido aos problemas com o aumento da resist?ncia parasit?ria aos antihelm?nticos, tem crescido o interesse sobre o efeito medicinal das plantas no sentido de encontrar novas alternativas e m?todos para controle da preval?ncia e severidade das infec??es por ciatostom?neos. O efeito da temperatura sobre o desenvolvimento de ovos dos ciatostom?neos e o tempo de armazenamento das fezes s?o pouco estudados, sendo este o primeiro trabalho realizado in vitro sob condi??es de estoque em baixas temperaturas. Este trabalho objetivou avaliar o desenvolvimento de ovos de ciatostom?neos recuperados de fezes mantidas sob diferentes temperaturas e testar o efeito de extratos de plantas sobre as fases pr?paras?ticas desse parasito, sendo dividido em dois cap?tulos. O cap?tulo I trata da avalia??o da influ?ncia de baixas temperaturas sobre o desenvolvimento dos ovos at? o primeiro est?gio larval (L1) e terceiro est?gio larval (L3), sendo dividido em quatro etapas com modifica??es na metodologia. Para a execu??o dos experimentos, fezes foram coletadas diretamente de equinos n?o vermifugados. Posteriormente, foram realizados a contagem de ovos por grama de fezes (OPG) para estimativa da carga parasit?ria de cada animal doador e coproculturas para identifica??o das L3. A massa total foi homogeneizada e as amostras reservadas foram mantidas armazenadas sob diferentes temperaturas: refrigera??o (?10?C) e congelamento (-4?C), durante o per?odo de execu??o de cada experimento. Semanalmente ou quinzenalmente, conforme a metodologia adotada no experimento, ovos (?300) foram recuperados e mantidos em placas de petri ? temperatura ambiente (?25?C), sendo observados ao microsc?pio ?ptico (40x) ap?s 24h para contagem das diferentes fases de desenvolvimento do ovo at? L1. As L3 foram recuperadas por meio de coproculturas. O cap?tulo II tratou da avalia??o do efeito do extrato aquoso de duas plantas, Solanum lycocarpum e Curatella americana, sobre ovos, L1 e L3 de ciatostom?neos. Ovos foram recuperados (?400) de massa fecal fresca, as L1 (?400) ap?s 24h, e as L3 atrav?s da t?cnica de coprocultura. Os experimentos foram conduzidos separadamente, a fim de avaliar o percentural de inibi??o do desenvolvimento dos ovos (%IDO) e o percentual de efic?cia na mortalidade larval (%LM) pela a??o dos extratos em tr?s diferentes concentra??es (5, 2,5 e 1%) durante 24h. Esse foi o primeiro trabalho realizado com avalia??o e observa??o do desenvolvimento de ovos de ciatostomineos em baixas temperaturas, durante as esta??es. Atrav?s dos estudos apresentados no capitulo I observou-se varia??o no desenvolvimento dos ovos at? o est?gio de L3 nas diferentes esta??es, em amostras mantidas sob ?10?C e -4?C. No capitulo II, observou-se que os extratos aquosos das plantas avaliadas apresentaram melhor efeito larvicida sobre as L1 e n?o apresentaram efeito ovicida sobre os ovos de ciatostom?neos. Conclui-se que a temperatura de congelamento n?o matou os ovos; as massas fecais podem ser estocadas por um per?odo de 30 dias para diagn?sticos e mais estudos precisam ser realizados in vitro com extratos aquosos da Solanum lycocarpum e Curatella americana, a fim de verificar o potencial anti-helm?ntico em outras concentra??es.