Gastrointestinal Parasites in Sheep from the Brazilian Pampa Biome: Prevalence and Associated Factors.

Parasitic infections are common in sheep farming worldwide. A cross-sectional study was carried out to determine the prevalence and associated risk factors among gastrointestinal parasites and sheep herds from the Brazilian Pampa biome, Rio Grande do Sul state, Brazil. Twenty-one farms were visited, where rectal faecal samples were individually collected from 309 animals. The sheep industry on the studied farms was characterised by small farms with a low level of technification, an extensive grazing system and meat production. Of all samples analysed, strongyle nematodes had the highest prevalence (77.02%), followed by Eimeria spp. (70.55%), Moniezia expansa (20.39%) and Strongyloides papillosus (17.48%). Mixed infection, between helminths and protozoans, was detected in 68.61% of samples. All herds were positive for strongyle and Eimeria spp. A predominance of Haemonchus spp. and Trichostrongylus spp. nematodes was observed in the herds. Younger animals were significantly more affected by Eimeria and M. expansa. In the semi-intensive and intensive systems, a higher frequency of Eimeria and strongyle infections was observed. Parasite infection was significantly reduced at low animal densities. The Brazilian Pampa region presents a high prevalence of gastrointestinal parasites among sheep; age, breeding system and stocking density were factors associated with parasite infection.

As infecções parasitárias são comuns na criação de ovinos em todo o mundo. Um estudo transversal foi realizado para determinar a prevalência e fatores de risco associados entre parasitoses gastrintestinais e rebanhos ovinos do bioma Pampa brasileiro, estado do Rio Grande do Sul, Brasil. Vinte e uma fazendas foram visitadas, onde foram coletadas amostras de fezes individuais da ampola retal de 309 animais. A produção ovina era caracterizada por pequenas propriedades com baixo nível de tecnificação, os animais eram criados em sistema extensivo e para produção de carne. De todas as amostras analisadas, os estrongilídeos (Nematoda: Strongylida) foram mais prevalentes (77,02%), seguido por Eimeria spp. (70,55%), Moniezia expansa (20,39%) e Strongyloides papillosus (17,48%). Infecção mista, entre helmintos e protozoários, foi detectada em 68,61% das amostras. Todos os rebanhos foram positivos para estrongilídeos e Eimeria spp. Foi observada predominância dos nematódeos Haemonchus spp. e Trichostrongylus nos rebanhos. Animais mais jovens foram significativamente mais afetados por Eimeria e M. expansa. Nos sistemas semi-intensivo e intensivo, observou-se maior frequência de infecções por Eimeria e estrongilídeos. A infecção parasitária foi significativamente menor em fazendas com baixa densidade animal. A região do Pampa brasileiro apresenta alta prevalência de parasitos gastrintestinais em ovinos; idade, sistema reprodutivo e densidade animal foram fatores associados à infecção parasitária.

Cryptosporidium spp. in Columba livia Gmelin, 1789 (Columbiformes: Columbidae) free-living pigeons from urban areas in Pelotas, Rio Grande do Sul, Brazil.

Cryptosporidium spp. are parasites with zoonotic potential that cause intestinal diseases, generally intense diarrheal, on their hosts, which tend to be immunocompromised. Large populations of pigeons in urban environments can lead to greater human exposure to Cryptosporidium spp., as this bird is considered a potential reservoir and is able to transmit several pathogens. This study aimed in determining the occurrence of Cryptosporidium spp. oocysts in feces of free-living pigeons (Columba livia) found in urban areas in the city of Pelotas, Rio Grande do Sul, south of Brazil. Fecal samples (n = 50) were collected from young and adult pigeons captured in different locations in the urban area and the parasitological diagnosis was performed through Ritchie's modified technique and Kinyoun's technique. Among the 50 samples, 18% (IC95% 9.7-30.8) were positive for Cryptosporidium spp. with a low number of oocysts being detected on fecal smears. Our results confirmed the occurrence of Cryptosporidium spp. oocysts in feces of free-living pigeons from the urban area of the city of Pelotas. This is the first report of Cryptosporidium spp. oocysts in feces of pigeons in south Brazil. This data has epidemiological significance because the oocysts could be from zoonotic species, which consequently shows that humans might be exposed to infection.

Purpureocillium lilacinum and Trichoderma virens for biological control of trichostrongylid parasites of sheep: an in vitro evaluation.

The study evaluated the ovicidal activity of enzymatic extracts of Purpureocillium lilacinum and Trichoderma virens against trichostrongylid eggs from sheep. Filtered extract (FE) and macerated crude extract (MCE) were prepared from fungal cultures in minimal broth. In the experiment, 100 trichostrongylid eggs, obtained from the feces of naturally infected sheep, were exposed to fungal extracts for 24 and 48 hours/25°C. In the control group, eggs were incubated in minimal broth. The number of L1 larvae was ascertained. Each treatment consisted of four repetitions and the experiment was repeated five times. It was observed that the effect of FE and MCE of P. lilacinum and T. virens on egg hatchability differed from that of the control group. MCE of T. virens and P. lilacinum showed higher ovicidal activity than FE over both periods and at 48 hours of exposure, respectively. From the percentage reductions in hatchability of the eggs, MCE was shown to be superior to FE for both fungi. This study demonstrated the ovicidal potential of these fungi against trichostrongylid eggs. However, further studies are needed in order to identify the molecules responsible for the ovicidal effects, and to evaluate the behavior of fungal extracts in biotic and abiotic interactions.

Exposure of Toxocara canis eggs to Purpureocillium lilacinum as a biocontrol strategy: an experimental model evaluation.

Purpureocillium lilacinum is a nematophagous fungus used in biological control against some parasites, including Toxocara canis. This study researched the infectivity of embryonated T. canis eggs after exposure to the fungus P. lilacinum. T. canis eggs were exposed to P. lilacinum for 15 or 30 days and subsequently administered to Swiss mice (n=20). Control group consisted of mice who received T. canis embryonated eggs without fungal exposure. Forty-eight hours after infection, heart, lung, and liver from animals of each group were collected to assess larval recovery. The organs of mice that received embryonated eggs exposed to the fungus showed a lower average larval recovery (P<0.05) suggesting that exposure of T. canis eggs to P. lilacinum was able to reduce experimental infection. Under the evaluated conditions, the interaction time between the fungus and the parasite eggs was not a significant factor in larvae recovery. P. lilacinum may be considered a promising T. canis biological control agent. However, further studies are needed to determine a protocol for the use of this fungus as a biological control agent.

Exposure of Toxocara canis eggs to Purpureocillium lilacinum as a biocontrol strategy: an experimental model evaluation / Exposição de ovos de Toxocara canis a Purpureocillium lilacinum como estratégia de biocontrole: uma avaliação em modelo experimental

Abstract Purpureocillium lilacinum is a nematophagous fungus used in biological control against some parasites, including Toxocara canis. This study researched the infectivity of embryonated T. canis eggs after exposure to the fungus P. lilacinum. T. canis eggs were exposed to P. lilacinum for 15 or 30 days and subsequently administered to Swiss mice (n=20). Control group consisted of mice who received T. canis embryonated eggs without fungal exposure. Forty-eight hours after infection, heart, lung, and liver from animals of each group were collected to assess larval recovery. The organs of mice that received embryonated eggs exposed to the fungus showed a lower average larval recovery (P<0.05) suggesting that exposure of T. canis eggs to P. lilacinum was able to reduce experimental infection. Under the evaluated conditions, the interaction time between the fungus and the parasite eggs was not a significant factor in larvae recovery. P. lilacinum may be considered a promising T. canis biological control agent. However, further studies are needed to determine a protocol for the use of this fungus as a biological control agent.

Resumo Purpureocillium lilacinum é um fungo nematófago com potencial para uso no controle biológico de parasitos, incluindo Toxocara canis. Este estudo pesquisou a infectividade de ovos de T. canis embrionados após exposição ao fungo P. lilacinum . Ovos de T. canis foram expostos ao fungo por 15 ou 30 dias e subsequentemente administrados a camundongos Swiss (n=20). O grupo controle consistiu de camundongos que receberam ovos embrionados do parasita sem exposição ao fungo. Quarenta e oito horas após a infecção, coração, pulmão e fígado dos camundongos foram coletados para avaliar a recuperação larval. Os órgãos dos animais que receberam ovos embrionados expostos ao fungo apresentaram menor média de recuperação larval (P<0,05) do que os infectados com ovos sem exposição ao fungo, sugerindo que a exposição dos ovos de T. canis a P. lilacinum foi capaz de reduzir a infecção experimental. Nas condições avaliadas, o tempo de interação entre o fungo e os ovos do parasito não foi um fator significativo na recuperação das larvas. P. lilacinum pode ser considerado um promissor agente de controle biológico de T. canis, no entanto, mais estudos são necessários para avaliar o emprego deste fungo como um agente de controle biológico.

Risk factors and infection due to Cryptosporidium spp. in dogs and cats in southern Rio Grande do Sul.

This study investigated the frequency of oocysts of Cryptosporidium spp. in feces from dogs and cats in five municipalities in the southern region of the state of Rio Grande do Sul. The risk factors associated with infection were also investigated. Feces samples from 110 dogs and 18 cats were stained using the auramine method. At the time of feces sampling, a questionnaire with semi-open-ended questions was applied to the animal guardians and all data obtained underwent statistical analysis. The real frequency of oocysts of Cryptosporidium spp. was 24.63% (27 dogs and two cats). Only four samples of dog feces were diarrheic and no presence of oocysts was observed in any of them. Variables that represented risk factors for infection were: homemade food, untreated water, circulation of animals on grassy terrain and living in the same environment as other animals (cattle). The results made it possible to inferring that within the population studied, the frequency of parasitism due to Cryptosporidium spp. in dogs was relevant and emphasize the asymptomatic nature of this infection. The adopting control measures are highlighted, particularly in relation to variables that represent risk factors for this infection.

Risk factors and infection due to Cryptosporidium spp. in dogs and cats in southern Rio Grande do Sul / Fatores de risco e infecção por Cryptosporidium spp. em cães e gatos no sul do Rio Grande do Sul

Abstract This study investigated the frequency of oocysts of Cryptosporidium spp. in feces from dogs and cats in five municipalities in the southern region of the state of Rio Grande do Sul. The risk factors associated with infection were also investigated. Feces samples from 110 dogs and 18 cats were stained using the auramine method. At the time of feces sampling, a questionnaire with semi-open-ended questions was applied to the animal guardians and all data obtained underwent statistical analysis. The real frequency of oocysts of Cryptosporidium spp. was 24.63% (27 dogs and two cats). Only four samples of dog feces were diarrheic and no presence of oocysts was observed in any of them. Variables that represented risk factors for infection were: homemade food, untreated water, circulation of animals on grassy terrain and living in the same environment as other animals (cattle). The results made it possible to inferring that within the population studied, the frequency of parasitism due to Cryptosporidium spp. in dogs was relevant and emphasize the asymptomatic nature of this infection. The adopting control measures are highlighted, particularly in relation to variables that represent risk factors for this infection.

Resumo Este estudo verificou a frequência de oocistos de Cryptosporidium spp. em fezes de cães e gatos em cinco municípios da região sul do Rio Grande do Sul e fatores de risco associados à infecção. Amostras de fezes de 110 cães e 18 gatos foram coradas pelo método de auramina. No momento da coleta de fezes aplicou-se um questionário aos tutores dos animais com questões semiabertas e os dados foram submetidos à análise estatística. A frequência verdadeira de oocistos de Cryptosporidium spp. foi de 24,63% (27 cães e 2 gatos). Apenas quatro amostras de fezes caninas eram diarreicas e todas sem oocistos. As variáveis que representaram fatores de risco para a infecção foram: alimentos de preparo caseiro, água não tratada, circulação dos animais em terreno gramíneo e convivência com outros animais, principalmente bovinos. Os resultados sugerem que a frequência de cães parasitados por Cryptosporidium spp. é relevante, reforçando o caráter assintomático da infeção. Destaca-se a importância da adoção de medidas de controle, particularmente das variáveis que representaram fatores de risco à infecção.