The transcriptome of Cryptosporidium oocysts and intracellular stages.

Human cryptosporidiosis is caused primarily by two species of apicomplexan parasites, Cryptosporidium parvum and C. hominis. Although infection of cell monolayers with sporozoites does not support the complete parasite life cycle, the in vitro system is used to study the asexual phase of multiplication, which consists of two generations of merogony. To better understand host-parasite interaction and to gain insight into gene regulatory processes driving the complex life cycle of Cryptosporidium parasites, we analyzed the transcriptome of C. parvum in oocysts, sporozoites and infected cell monolayers 2-48 h post-infection. Analysis of RNA-Seq data from replicate oocyst, sporozoite and intracellular samples revealed significant differences between transcriptomes expressed outside and inside the host cell. Compared to the transcriptome found in the host cell, the oocyst transcriptome is less diverse. Biological processes significantly over-represented intracellularly relate to biosynthetic processes. Genes significantly overexpressed in oocysts show evidence of specialized functions not found in other Apicomplexa. A more comprehensive view of gene regulation during the Cryptosporidium life cycle will require the analysis of later time points during the infection, particularly of the poorly studied sexual phase of the life cycle.

Circulation of canine parvovirus among dogs living in human-wildlife interface in the Atlantic forest biome, Brazil.

Despite of the role of domestic dogs as reservoirs for threatening viral diseases for wild carnivores, few studies have focused to identify circulation of viruses among dogs living in human/wildlife interfaces. To identify canine parvovirus (CPV) types circulating in dogs living in an Atlantic forest biome, faecal samples (n = 100) were collected at the same period (one week) corresponding to each of four areas, during 2014 to 2016 and corresponded to 100 different individuals. CPV was isolated in cell culture from 67 out 100 (67%) samples from healthy dogs. Cytopathic effects were characterized by total or partial cell culture lysis. Genome sequences of CPV-2a (10%), CPV-2b (7%) and CPV-2c (50%) were concomitantly detected by PCR and nucleotide sequencing. The current study addresses the importance of monitoring CPV circulation among dogs presenting potential contact with wildlife species.

First Molecular Characterization of Cryptosporidium spp. Infecting Buffalo Calves in Brazil.

With the aim of determining the occurrence of Cryptosporidium spp., 222 fecal samples were collected from Murrah buffalo calves aged up to 6 mo. Fecal DNA was genotyped with a nested polymerase chain reaction targeting the 18S rRNA gene and sequencing of the amplified fragment. Nested 18S PCR was positive for 48.2% of the samples. Sequence analysis showed that the most frequent species in these animals was Cryptosporidium ryanae, which was present in buffalo calves as young as 5 d. The zoonotic species Cryptosporidium parvum was detected in one animal. An uncommon Cryptosporidium 18S genotype was found in buffaloes.

Experimental infection of pregnant queens with two major Brazilian clonal lineages of Toxoplasma gondii.

Toxoplasma gondii isolates from Brazil are biologically and genetically different from European and North America isolates. Recently, four genotypes were considered the common clonal lineages in Brazil and were designated as types BrI, BrII, BrIII, and BrIV. The pathogenicity of two major Brazilian lineages was investigated after oral inoculation of queens in the middle third of their pregnancies with T. gondii cysts. Twelve pregnant queens without T. gondii antibodies were distributed in group A (infected with a type BrI isolate); group 2 (infected with type BrIII isolate), and group 3 (non-infected control). Infection with type BrI isolate caused toxoplasmosis manifestations and abortion from one litter. Toxoplasmosis manifestations besides premature stillbirth of one litter were observed in queens infected with type BrIII isolate. Indirect fluorescence antibody test showed T. gondii antibodies in all eight infected queens at 30 days after inoculation. In two 10-day-old kittens of the same litter (group 1), titers of 16 and 64 were detected. At the same time, titers of 16, 32, and 32 were detected in three kittens from the same litter (group 2). Experimental infection with tissue cysts from a type BrI and type BrIII isolates of T. gondii developed similar reproductive disturbance in primary infected pregnant queens.

[Comparison between coproparasitological techniques for the diagnosis of helminth eggs or protozoa oocysts in dogs]. / Comparação entre técnicas coproparasitológicas no diagnóstico de ovos de helmintos e oocistos de protozoários em cães.

In this study we evaluated the frequency of enteroparasites in pet dogs and their association with age, sex and breed, as well as the efficiency of the Willis-Mollay, Faust, Sedimentation and Direct exam methods. By these methods we processed 401 fecal samples. The samples were positive in the following percentages: Ancylostoma spp. (53.1%), Toxocara canis (20.7%), Cystoisospora ohioensis (15.7%), Trichuris vulpis (3.7%), Dipylidium caninum (2.5%) and Taenia spp. (1.0%). Toxocara canis (67.3%) and C. ohioensis (47.3%) showed higher positivity in the puppies. The Willis-Mollay technique was more efficient in the diagnosis of Ancylostoma spp. and T. canis eggs. The Direct method was the least efficient. It was found that the majority of the cases of D. caninum were diagnosed by the Sedimentation method (8=2.0%), while for T. vulpis Willis-Mollay (12=3.0%) and Sedimentation (13=3.2%) were more efficient. In view of these results, we can recommend the association of Willis-Mollay and Sedimentation methods for the diagnosis of gastrointestinal helminths. Due to the elevated occurrence of Ancylostoma spp. and T. canis, which are involved in zoonotic diseases, it becomes necessary to apply more efficient prophylaxis of canine intestinal parasitosis at the City of Araçatuba, state of São Paulo.