No abstract

Brazil is one of the regions with the highest prevalences of Toxoplasma gondii in humans and animals. Because free-range chickens become infected by feeding from ground contaminated with oocysts, the prevalence of T. gondii in this host has been widely used as an indicator of the strains prevalent in the environment. The genetic variability among T. gondii isolates from different healthy and sick hosts all over the world has been recently studied. Three clonal genetic lineages (Types I, II and III) were initially recognised as predominant in Western Europe and the United States. T. gondii strains are genetically diverse in South America. In Brazil, recombination plays an important role in strain diversification. The objective of this study was to genetically characterise T. gondii isolates from free-range chickens from Espírito Santo state, Southeast region, Brazil, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A total of 44 isolates among 47 previously described isolates (TgCkBr234-281) from free-range chickens were included in this study. Strain typing was performed using 12 PCR-RFLP markers: SAG1, SAG2, alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3. Eleven genotypes were identified. Ten isolates (23%) were grouped into four novel genotypes. Four isolates, distributed in four counties, corresponded to the Type BrI lineage, the genotype found most frequently in Brazil. No clonal Types I, II or III lineages were found. Two novel genotypes were represented by single isolates. Unique alleles were identified for the markers SAG1, c22-8 and CS3, and for the first time, a unique allele was found for the marker SAG3. Although a large number of T. gondii genotypes have already been identified from a variety of animal hosts in Brazil, new genotypes are continuously identified from different animal species. This study confirmed the diversity of T. gondii in Brazil and demonstrates clonal Type I, II and III lineages are rare in this country.

Human toxocariasis may be acquired by eating raw chicken liver. However, there are no reports on the prevalence of natural infection of chickens with Toxocara. The aim of this study was to evaluate the presence of anti-Toxocara antibodies as indicators of natural infection with Toxocara, in free-range chickens from Espírito Santo State, Brazil. An ELISA test with secretory and excretory Toxocara canis antigens was used. Negative controls were 20 industrial chickens reared in a high hygiene standard environment. Positive control serum was from a chicken infected with embryonated eggs of T. canis. Sera were adsorbed with Ascaridia galli extract to reduce cross-reactivity. Cut-off was the mean plus four times the standard deviation of optical density (OD) in negative group. One hundred and fifty-seven sera from free-range chicken were investigated. Results showed 58.5% of the chickens were positive with ELISA test; 12.7% had OD over the positive control and may be considered as true infected chickens. The results between the cut-off and the positive control may include infections with low titers of antibodies or may represent serum scar of past infection or may be the result of cross-reaction with other nematodes rather than A. galli which is used for the adsorption of sera. In conclusion, high prevalence of Toxocara sp. antibodies demonstrates natural infection of free-range chickens from Espírito Santo State which may represent a risk of infection with this nematode in people who have the habit of eating raw or undercooked chicken meat or viscera. The results also suggest that chickens may be useful as sentinels to detect soil contaminated with Toxocara eggs.

ResumoA toxoplasmose tem como agente etiológico Toxoplasma gondii, possui distribuição mundial sendo de extrema importância médico-veterinária, uma vez que pode causar aborto e doenças congênitas em várias espécies de hospedeiros intermediários, além de ser considerada uma importante zoonose. O objetivo deste estudo foi pesquisar a soroprevalência de anticorpos antiToxoplasma gondii em ovinos da raça Santa Inês, criados em diferentes regiões dos municípios da Grande Vitória no estado do Espírito Santo (ES). Foram coletadas amostras de sangue de 236 ovinos criados em seis propriedades rurais dos municípios de Vila Velha, Guarapari, Serra e Cariacica. Os soros foram submetidos à reação de Hemaglutinação Indireta (HAI) para a detecção de anticorpos anti-T.gondii da classe IgG. A prevalência encontrada de soroconversão foi de 38,5%. Em relação à faixa etária, foram encontrados 5,4% positivos nos animais jovens e 33,0% nos adultos. A presença de gato, animais silvestres, o trânsito de animais e as condições de higiene das instalações influenciam diretamente na ocorrência da toxoplasmose em ovinos. Palavras-chave:Toxoplasma gondii, toxoplasmose, ovinos, soroprevalência. AbstractToxoplasma gondii, toxoplasmosis agent, possessing a cosmopolitan distribution is extremely important veterinary medication because it can cause miscarriages and congenital diseases in various species of intermediate hosts in addition to being considered one of the major zoonoses. The aim of this study was to investigate the seroprevalence of antibodies to Toxoplasma gondii in sheep of Santa Ines, created in different regions of the cities of Vitória in Espírito Santo (ES). Were collected blood samples from 236 sheep reared on six farms in the municipalities of Vila Velha, Guarapari, Sierra and Cariacica. Sera were submitted to the reaction of indirect hemagglutination (IHA) for detection of anti-T gondii IgG. The prevalence of seroconversion was 38.5%. In terms of age group 5.4% were found positive in young animals and 33.0% in adults. The presence of cats, wild animals, the transit of animals and the hygiene conditions of premises directly influence the incidence of toxoplasmosis in sheep.