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Visceral leishmaniasis is an important parasitic disease that affects humans and animals. The response against the protozoan involves the interaction of both innate and adaptive branches of the immune system, and an important immune sensor is represented by the toll-like receptor (TLR) family. Here, we investigated the pattern of TLR-2, TLR-4 and TLR-9 gene expression in different compartments (brain, choroid plexus, spleen and lymph node) of dogs naturally infected with Leishmania infantum. Gene expression of the TLRs varied according to the compartment evaluated. In the brain, there was only an upregulation of TLR-2, whereas in the choroid plexus, TLR-2 and TLR-9 were both upregulated. Further, the peripheral lymphoid organs (spleen and lymph nodes) showed increased TLR-2 and TLR-4 expression. This study provides the first insight about TLR expression in the central nervous system of infected dogs, and gives additional evidence of the compartmentalization of the immune response during visceral leishmaniasis.

Due to the scarcity of information related to the epidemiology of Cryptosporidium infection in passerine birds, this study aimed to determine the periodicity of fecal shedding of Cryptosporidium spp. oocysts, after natural infection, and its clinical signs, mortality, and molecular characterization. Four hundred eighty fecal samples were collected from 40 birds, including 372 samples from 31 adult birds and 108 samples from nine young birds (up to 12 months old), housed in five aviaries, monthly from September 2007 to September 2008, with the exception of April. The birds originated from aviaries in which the following species were raised: great-billed seed-finch (Oryzoborus maximiliani), lesser seed-finch (Oryzoborus angolensis), ultramarine grosbeak (Cyanocompsa brissonii), and rusty-collared seedeater (Sporophila collaris). The samples were preserved in 2.5% potassium dichromate at 4 degrees C until processing. The oocysts were purified by centrifugal flotation in Sheather's solution, followed by genomic DNA extraction and molecular characterization of oocysts using the nested polymerase chain reaction for amplification of fragments of the 18S subunit of rRNA gene. Intermittent shedding of oocysts was observed by positive amplification for Cryptosporidium spp. in 91 (24.5%) samples of adult birds and 14 (13%) of young birds. The sequencing of the amplified fragments enabled the identification of Cryptosporidium galli. Although all the aviaries had birds positive for C. galli, morbidity or mortality was observed in only one aviary and was associated with concomitant infection with Escherichia coli and Isospora sp.

Cryptosporidium parvum infection is very important with respect to public health, owing to foodborne and waterborne outbreaks and gastrointestinal illness in immunocompetent and immunocompromised persons. In cattle, infection with this species manifests either as a subclinical disease or with diarrheal illness, which occurs more often in the presence of other infectious agents than when alone. The aim of this study was to develop a real-time polymerase chain reaction (PCR) assay for the detection of C. parvum in calf fecal samples and to compare the results of this assay with those of the method routinely used for the diagnosis of Cryptosporidium spp., nested PCR targeting the 18S rRNA gene. Two hundred and nine fecal samples from calves ranging in age from 1 day to 6 months were examined using real-time PCR specific for the actin gene of C. parvum and by a nested PCR targeting the 18S rRNA gene of Cryptosporidium spp. Using real-time PCR detection, 73.2% (153 out of 209) of the samples were positive for C. parvum, while 56.5% (118 out of 209) of the samples were positive for Cryptosporidium spp. when the nested PCR amplification method was used for the detection. The analytical sensitivity of the real-time PCR was approximately one C. parvum oocyst. There was no significant nonspecific DNA amplification of any of the following species and genotype: Cryptosporidium andersoni, Cryptosporidium baileyi, Cryptosporidium bovis, Cryptosporidium canis, Cryptosporidium galli, Cryptosporidium ryanae, Cryptosporidium serpentis, or avian genotype II. Thus, we conclude that real-time PCR targeting the actin gene is a sensitive and specific method for the detection of C. parvum in calf fecal samples.

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O presente estudo teve como objetivo comparar as técnicas de imunofluorescência direta (IFD) e a microscopia de contraste de fase em solução de Sheather (MCF), para detecção de oocistos de Cryptosporidium spp. em amostras fecais de bezerros. A determinação dos limiares detecção da IFD e da MCF foi realizada utilizando cinco alíquotas de uma amostra fecal de bezerro, comprovadamente negativa para Cryptosporidium spp., adicionadas com diferentes quantidades de oocistos de Cryptosporidium parvum. Ao exame das 5 alíquotas, a IFD e a MCF apresentaram, respectivamente, limiares de detecção de 3,3x104 (duas alíquotas positivas) e 3,3x105 oocistos (1 alíquota positiva) por grama de fezes. Foram também realizadas a comparação entre a positividade obtida e uma análise semiquantitativa do número de oocistos observados por campo de microscopia, em ambos os métodos, em 300 amostras fecais de bezerros. Entre as 300 amostras, 19,7% (59/300) foram positivas pela IFD, com diferença estatisticamente significante (P=0,0098) quando comparada com a positividade obtida pela MCF, que foi de 11,7% (35/300). As amostras positivas foram submetidas à reação em cadeia da polimerase para amplificação de fragmentos da subunidade 18S do rRNA, com posterior sequenciamento dos fragmentos amplificados, o que permitiu a identificação de Cryptosporidium andersoni em 11,9% (7/59) e de C.parvum em 88,1% (52/59) das amostras. Os resultados observados comprovam que a IFD foi mais eficiente que a MCF para detecção de oocistos de Cryptosporidium spp. em amostras fecais de bezerros.

 RESUMOA infecção por algumas espécies ou genótipos de Cryptosporidium representa um risco em potencial para a saúde pública, principalmente por causa de morbidade e mortalidade em crianças de zero a cinco anos de idade e em pacientes imunodeprimidos. Embora existam alguns relatos de infecção por Cryptosporidium em animais de companhia, sua participação na epidemiologia da criptosporidiose humana é incerta, e a literatura sobre esse tema ainda é bastante escassa. O objetivo deste estudo foi determinar a ocorrência e realizar a classificação molecular de Cryptosporidium spp. em amostras fecais de animais exóticos criados como animais de estimação no Brasil. Um total de 386 amostras de seis espécies de animais foi colhido e armazenado em solução de dicromato de potássio 5% a 4°C. Os oocistos foram purificados por centrífugo-sedimentação em água/éter, seguindo-se a extração de DNA genômico e a realização da nested PCR para amplificação de fragmento parcial do gene da subunidade 18S do rRNA. Positividade para Cryptosporidium spp. foi observada em 11,40% (44/386) das amostras. O sequenciamento de fragmentos amplificados permitiu a identificação de Cryptosporidium tyzzeri em camundongos, Cryptosporidium muris em camundongos, hamster e chinchila, Cryptosporidium parvum em chinchila, Cryptosporidium genótipo hamster em hamster e Cryptosporidium sp. em porquinho-daíndia. Os resultados deste estudo mostram que há uma variedade de espécies de Cryptosporidium presentes em animais exóticos de companhia no Brasil. Os dados sugerem que esses animais podem participar da epidemiologia da criptosporidiose humana, particularmente por seu estreito convívio. Palavras-chave: PCR, saúde pública, zoonoses ABSTRACT Infection by some species or genotypes of Cryptosporidium represents a potential risk to public health, mainly because of the morbidity and mortality in children from zero to five years of age and in immunocompromised patients. Although there are some reports of Cryptosporidium infection in animals raised as pets, their participation in the epidemiology of human cryptosporidiosis is uncertain and studies on this topic are still scarce. The aim of this study was to determine the occurrence, as well as to perform the molecular classification of Cryptosporidium spp. in faecal samples of exotic animals raised as pets in

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