S.L.P. Souza

Prevalence of Toxoplasma gondii and Neospora caninum infections in sheep from Federal District, central region of Brazil

Serum samples from 1028 sheep were collected from 32 herds within Federal District, in the central region of Brazil. The samples were examined by indirect fluorescent antibody test (IFAT) using sera diluted 1:64 and 1:50 as cut-off values for the detection of antibodies against Toxoplasma gondii and Neospora caninum, respectively. The observed prevalence for T. gondii infection was 38.22% (26.81%<CI 0.95<49.62%), and the titers ranged from 64 to 65536. The observed prevalence for N. caninum infection was 8.81% (7.08%<CI 0.95<10.53%). The titers ranged from 50 to 51200. The reactant sera to both pathogens corresponded to 4.67% of the samples. The risk factors were not determined because of the absence of negative herds for T. gondii and the high proportion of positive herds for N. caninum (87.50%). The prevalence for T. gondii infection was significantly higher among males than in females. The present work is the first report on seroprevalence of T. gondii and N. caninum in sheep from Federal District and shows that infection by both parasites is widespread in the ovine population from this region.

Prevalence of antibodies to Neospora caninum in dogs from Amazon, Brazil

Neospora caninum is an important cause of abortion in dairy cattle worldwide. Dogs are important in the epidemiology of this parasite because they are the only hosts known to excrete N. caninum oocysts. Antibodies to N. caninum were assayed in serum samples from 157 dogs from Monte Negro, Rondônia, Amazon, Brazil using the indirect fluorescent antibody test. Antibodies to N. caninum were found in 13 (8.3%) of dogs in titers of 1:50 in 1, 1:100 in 2, 1:200 in 5, 1:800 in 1, 1:1600 in 2, and 1:3200 in 2 dogs. These data indicate that N. caninum infection is prevalent even in remote areas of the Amazon.

Prevalência de carrapatos em cães de áreas rurais da região norte do Estado do Paraná

During January and February, 2000, 133 dogs from 21 farms located in eight diferent counties at the northern region of Parana, Brazil, were examined for ticks. Ticks found on dogs were collected and identified. Information about dog rearing system was also obtained. Fifty-five ticks were collected on 19 dogs (14.3%) from 11 farms (52.4%). Four species were identified: Rhipicephalus sanguineus (20 ticks on nine dogs from seven farms), Boophilus microplus (15 ticks on five dogs from five farms), Amblyomma ovale (nine ticks on six dogs from four farms) and Amblyomma aureolatum (11 ticks on three dogs from one farm). The results are discussed considering the behavior of some dogs used to stroll into the woods and pasture areas whereas other dogs remained closer to the human facilities.

Molecular phylogenetic analysis in Hammondia-like organisms based on partial Hsp70 coding sequences

The 70 kDa heat-shock protein (Hsp70) sequences are considered one of the most conserved proteins in all domains of life from Archaea to eukaryotes. Hammondia heydorni, H. hammondi, Toxoplasma gondii, Neospora hughesi and N. caninum (Hammondia-like organisms) are closely related tissue cyst-forming coccidians that belong to the subfamily Toxoplasmatinae. The phylogenetic reconstruction using cytoplasmic Hsp70 coding genes of Hammondia-like organisms revealed the genetic sequences of T. gondii, Neospora spp. and H. heydorni to possess similar levels of evolutionary distance. In addition, at least 2 distinct genetic groups could be recognized among the H. heydorni isolates. Such results are in agreement with those obtained with internal transcribed spacer-1 rDNA (ITS-1) sequences. In order to compare the nucleotide diversity among different taxonomic levels within Apicomplexa, Hsp70 coding sequences of the following apicomplexan organisms were included in this study: Cryptosporidium, Theileria, Babesia, Plasmodium and Cyclospora. Such analysis revealed the Hammondia-like organism to be the lowest divergent group when compared to other groups within the phylum Apicomplexa. In conclusion, the Hsp70 coding sequences proved to be a valuable genetic marker for phylogenetic reconstruction and may constitute a good candidate to be used with other genes for species phylogeny within this group of organisms.

Genotyping of potentially zoonotic Giardia duodenalis from exotic and wild animals kept in captivity in Brazil

We have studied the variability of glutamate dehydrogenase (gdh) and small subunit ribosomal (SSU) rRNA coding genes of Giardia species in fecal samples isolated from wild and exotic animals in Brazil, and compared with homologous sequences of isolates from human and domestic animals characterized in previous studies. Cysts of Giardia duodenalis were obtained from feces of naturally infected monkeys (Alouatta fusca) (n=20), chinchillas (Chinchilla lanigera) (n=3), ostriches (Struthio camelus) (n=2) and jaguar (Panthera onca) (n=1). Assemblage AI was assigned to the unique isolate of jaguar. All the samples from monkeys, chinchillas, and ostriches were assigned to Assemblage B. There was little evolutionary divergence between the referred isolates and isolates described elsewhere. The Assemblage B isolates identified in this study were closely related to Assemblage BIV isolated from humans. The molecular identification of Assemblages A and B of G. duodenalis isolates from exotic and wild animals demonstrates that such hosts may be a potential reservoir for zoonotic transmission of G. duodenalis.

Seroprevalence of toxoplasmosis in a low-income community in the São Paulo municipality, SP, Brazil

Toxoplasmosis is one of the most common zoonoses worldwide. The seroprevalence for T. gondii in human population from Brazil might range from 40 to 80%. The aim of this paper was to study the seroprevalence of T. gondii infection in children from age one to 15 living in a low socioeconomic community, named community of Jardim São Remo in the year of 2002. The community is located in the West area of São Paulo municipality, São Paulo State, Brazil. Antibodies to T. gondii were found in 110 (32.4%, CI 95%: 27.5 - 37.7) of the 339 children tested with indirect immunofluorescent antibody test. The titration of the samples revealed 29 children with serum titer equal to 16, 14 children with 32, 18 children with 64, 21 children with 128, 20 children with 256 and eight children with serum titer > 512. The age dependence of the prevalence of T. gondii infection and the association between seroprevalence for T. gondii and seroprevalence for T. canis suggest that the infection is chiefly postnatal. Seroconversion in infant population of community Jardim São Remo occurs in children as young as two years old, earlier than in the children attended at health centers of São Paulo city. The seroprevalence of T. gondii in children from Jardim São Remo was compared to the prevalence in children from other urban centers of Brazil.

Determinação da contagem de ovos de nematódeos no período peri-parto em vacas

Dois experimentos foram conduzidos com o objetivo de se observar as alteracoes do numero de ovos de nematodeos por grama de fezes (OPG) eliminados por vacas no periodo do peri-parto. No primeiro foram utilizadas vacas de racas europeia (leiteiras) e zebuinas (de corte), da 6a semana pre-parto a 6a semana pos-parto. Observou-se diferenca significativa (p<0,05) com maior numero de animais leiteiros apresentando ovos de nematodeos nas fezes durante o peri-parto. Na categoria de animais leiteiros, houve um aumento significativo no OPG no momento do parto e na semana quatro pos-parto, em relacao ao pre-parto. Tambem nesta categoria, observou-se uma associacao negativa entre o numero de partos e a positividade em relacao ao OPG (p<0,05). Devido ao comportamento diferenciado dos animais leiteiros um segundo experimento foi feito para se comparar, nessa categoria animal, as alteracoes de OPG da quarta semana pre-parto a decima pos-parto, em vacas de primeira e segunda crias e tres ou mais crias. Observou-se diferenca significativa, com os animais de primeira e segunda crias apresentando maiores valores de OPG nas semanas dois, tres e quatro pos-parto (p<0,05). Os valores de OPG para os animais de primeira e segunda crias foram de 0 - 1800, enquanto nos animais mais velhos a variacao foi de 0 - 150 OPG. Os resultados de ambos os estudos sugerem que um esquema de controle contra nematodeos gastrintestinais deva ser implantado em vacas de primeira e segunda crias com o uso de anti-helminticos no pre-parto, ao redor da segunda semana antes dos nascimentos.

Sobre a etiologia de um surto de disenteria de inverno em vacas leiteiras no Brasil

Winter dysentery (WD) is a seasonal infectious disease described worldwide that causes a marked decrease in milk production in dairy cows. In the Northern hemisphere, where the disease is classically recognized, bovine coronavirus (BCoV) has been assigned as a major etiologic agent of the disease. Nonetheless, in the Southern hemisphere, an in-deep etiological survey on WD cases had not been carried out. This study aimed to survey for BCoV by nested-RT-PCR, rotavirus by polyacrylamide gel electrophoresis (PAGE) and ELISA, bacteria by classical bacteriological methods and PCR for virulence factors and parasites by sugar flotation test on fecal samples of 21 cows from a farm during an outbreak of WD in Sao Paulo state, Southeastern Brazil. BCoV was detected in all 21 samples, while rotavirus was detected in two symptomatic cows. Escherichia coli, Yersinia intermedia, Providencia rustigianii Proteus penneri, Klebsiella terrigena and Enterobacter aglomerans were detected in samples from both asymptomatic and healthy cows in different associations. The study of E. coli virulence factors revealed that the strains isolated were all apathogenic. Cysts of Eimeria sp. and eggs of Strongyloidea were detected at low numbers in four of the symptomatic cows, with one co-infestation. These results suggest BCoV as the main etiologic agent of the cases of WD in Brazil, a conclusion that, with the clinical and epidemiological patterns of the disease studied herein, match those already described elsewhere. These findings give basis to the development of preventive measures and contribute to the understanding of the etiology of WD.

Isolation of rotavirus from asymptomatic dogs in Brazil

is subdivided both serologically, based on the inner capsid VP6 protein, and electropherotypically, based on the arrangement of the 11 dsRNA segments, into seven groups (A to G). Groups A, B, and C are found in both humans and animals, whereas groups D, E, F, and G have been found only in animals to date. In most cases, the electrophoretic pattern of the genome of group A rotaviruses is composed of four high-molecular-weight dsRNA segments (numbered 1 to 4), two middle-sized segments (5 and 6), a distinctive triplet of segments (7 to 9), and two smaller segments (10 and 11) (Estes and Kapikian, 2007). Canine rotavirus most often causes mild enteritis, especially in pups younger than two weeks, but the virus is also found in health animals (Schwers et al., 1983; Mochizuki et al., 1986). To date, only 10 isolates of canine rotavirus have been reported, including three isolates from the USA, two from France, two from Japan, two from Italy, and one from Korea (England and Poston, 1980; Fulton et al., 1981; Hoshino et al., 1982; Hoyois et al., 1982; Mochizuki and Hsuan,

Avaliação da performance do teste de aglutinação modifica (MAT) para a detecção de anticorpos anti-Toxoplasma gondii em cães

Toxoplasmosis is a zoonosis that has been the subject of study in Brazil and worldwide. The dogs are sentinels for the infection and can carry Toxoplasma gondii in the environment. Seroepidemiological surveys of these animals are an important tool in the surveillance and control of the disease and inform decision-making in health programs. In this study the performance of the Modified Agglutination Test (MAT) in the serodiagnosis of canine toxoplasmosis is evaluated and compared to the indirect immunofluorescent-antibody test (IFAT). A sample of 157 dog sera from the county of Monte Negro, Rondonia, with 76.40% positive reactions for Toxoplasma gondii (IFAT =16) was analyzed using the MAT (=25), presenting sensitivity of 85.00% (Confidence Interval 95.00%: 79.4 - 90.60%) and specificity of 100.00%.