Study of surface carbohydrates in Galba truncatula tissues before and after infection with Fasciola hepatica

The presence and distribution of surface carbohydrates in the tissues of Galba truncatula snails uninfected or after infection with Fasciola hepatica as well as on the surface of the snail-pathogenic larval stages of the parasite were studied by lectin labelling assay. This is an attempt to find similarities that indicate possible mimicry, utilised by the parasite as an evasion strategy in this snail-trematode system. Different binding patterns were identified on head-foot-mantle, hepatopancreas, genital glands, renopericardial complex of the host as well as of the snail-pathogenic larval stages of F. hepatica. The infection with F. hepatica leads to changes of labelling with Glycine max in the head-mantle cells and Arachis hypogaea in the tubular epithelium of the hepatopancreas. The lectin binding on the other snail tissues is not changed by the development of the larvae. Our data clearly demonstrated the similarity in labelling of G. truncatula tissues and the surface of the snail-pathogenic larval stages of F. hepatica. The role of glycosylation of the contact surfaces of both organisms in relation to the host-parasite interactions is also discussed.

Risk factors associated with the occurrence of Cryptosporidium parvum infection in calves / Fatores de risco associados à ocorrência de infecção por Cryptosporidium parvum em bezerros

Cryptosporidium parvum oocysts were detected in feces of dairy calves raised in Rio de Janeiro State and the risk factors involved in the infection were determined. A hundred calves aging up to 12-month-old from 13 dairy farms were sampled. Polymerase chain reaction was used to detect the presence of oocysts. The zoonotic C. parvum species was detected in 45 percent animals. Statistical risk factors analyses revealed an association between infection and animals raised in technical systems such as the use of milking equipment, milking cooler, and water trough(P<0.05).

Detectaram-se oocistos de Cryptosporidium parvum em fezes de bezerros leiteiros no estado do Rio de Janeiro e analisaram-se os fatores de risco envolvidos na infecção dos animais. Cem bezerros com idades de 0 a 12 meses, provenientes de 13 propriedades rurais, foram amostrados, e suas fezes examinadas pela reação em cadeia da polimerase para a detecção dos oocistos. A espécie zoonótica C. parvum foi detectada em 45 por cento dos animais. As análises estatísticas dos fatores de risco revelaram haver associação entre infecção e animais criados em propriedades tecnificadas, que usam ordenha mecanizada, resfriamento de leite e fazendas que continham reservatórios de água à disposição dos animais (P<0,05).

Pleomorfismo de oocistos de Cystoisospora felis (Wenyon, 1923) Frenkel, 1977 (Apicomplexa: Cystoisosporinae) induzido por differentes fontes de infecção / Pleomorfism of Cystoisospora felis (Wenyon, 1923) Frenkel, 1977 (Apicomplexa: Cystoisosporinae) oocysts induced by different sources of infection

Com o objetivo de avaliar as diferenças morfométricas dos oocistos esporulados de Cystoisospora felis oriundos de diferentesfontes de infecção: natural em gatos peri-domiciliados, experimental induzida por oocistos esporulados e experimental induzidapor hipnozoítas em vísceras de camundongos pré-inoculados por via oral com 106 oocistos esporulados de C. felis, foramutilizados 40 gatos, sendo 28 oriundos de áreas peridomiciliares do município de Seropédica, estado do Rio de Janeiro, dosquais foram obtidos oocistos de C. felis por infecção natural e 12 livres de coccídios, nascidos em laboratório. Estes últimosforam divididos em dois grupos com seis animais cada, que receberam por via oral inóculo contendo 106 oocistos esporuladose vísceras de camundongos inoculados previamente com C. felis, respectivamente. Os oocistos provenientes das três fontesde infecção foram diferentes entre si quando se consideraram os diâmetros polar e equatorial. No entanto, em relação aoíndice morfométrico, não houve variação. Os oocistos provenientes de infecção por vísceras foram pouco homogêneos emrelação aos oocistos oriundos de infecção experimental com oocistos esporulados e de infecção natural.

The present work aimed at to evaluate morphological differences that can be observed on Cystoisospora felis oocysts fromnatural, oocyst-borne experimental infection and mice viscera-borne experimental infection. For this reason, forty cats wereused in this experiment. Twenty-eight cats were taken in the municipality of Seropédica, State of Rio de Janeiro, which werecorresponded to natural infection and twelve coccidia-free kittens which were borne inside laboratory facilities. These coccidia-free cats were divided into two groups with six animals each: the first group was inoculated with 106 sporulated oocysts and thesecond one with mice visceras previously inoculated with 106 sporulated oocysts. Oocysts shed by these kittens submitted tothree sources of infection were different from each other, when were considered the length and width, although there was notvariation on the shape index of them. Oocysts proceeding from kittens fed on mice visceras showed lower homogeneity incomparison to oocysts that came from oocyst-to-oocyst experimental and natural infections.

Evaluation of QIAamp DNA mini kit for removing of inhibitors in detection of Cryptosporidium parvum oocysts in water samples by a nested- PCR assay

In recent years, there has been a dramatic increase in the occurrence of waterborne disease outbreaks caused by the Cryptosporidium parvum, and presence of this protozoan parasite in drinking water is a significant health problem faced by the water industry. A new strategy for detection of Cryptosporidium oocysts in water samples is PCR' based techniques. In this study a nested' PCR assay was designed for the specific amplification of a 199 bp DNA fragment of the gene encoding the heat shock protein [hsp70] of Cryptosporidium parvum oocysts. In order to prevent the inhibition of PCR amplification by substances contained in water samples, three DNA purification methods including QIAamp DNA mini kit, InstaGene Matrix, MagExtractor ' Genome were compared in concentrates of tap water samples spiked with the oocysts. After it was found that the QIAamp is only efficient purification technique, the efficiency of QIAamp and immunomagnetic separation for nested'PCR assay of various water samples was compared. The results show that QIAamp provide a useful and rapid tool for removing of PCR inhibitors. It seems that QIAamp purification- nested PCR assay is a sensitive, rapid and cost effective method for detection of Cryptosporidium parvum oocysts in clean water samples with turbidity < 2 nephelometric turbidity unit [NTU]

Effect of some stool preservatives on the detection of cryptosporidium parvum oocysts using direct immunofluorescent assay

Cryptosporidium have been documented to be one of the main causative organisms in waterborne gastroenteritis in children. In the present study, a polyspecific anti- Cryptosporidium oocyst antibodies have been raised in pathogen rabbit and used to detect C. parvum oocysts in stool using direct immunofluorescent assay [DIFA]. The effect of different common laboratory preservatives on the stability of C. parvum oocysts was studied. A total number of 316 stool specimens have been collected from diarrheic children ranging in age from one month to 12 years attending the Suez Canal University Hospital. The stability of oocysts stored for one month at room temperature and at 4°C in 10% formalin, 2.5% potassium dichromate, polyvinyl alcohol [PVA], sodium-acetate-formalin [SAF] and merthiolate-iodine-formaldehyde [MIF] was tested against the developed antibodies using DIFA at different time intervals [1, 3, 7, 14 and 30 days]. The percentage of infection was 6% and it was common in infants [less than 2 years] than in children [above 2 years]. The results revealed that the most effective preservative was 10% formalin at both temperatures if the samples were used within two weeks of preservation. 2.5% potassium dichromate seemed to be the second efficient preservative, if the samples were preserved at 4°C, and used within the first week of preservation. Unpreserved [control] and preserved samples in PVA and SAF could be used if DIFA was done on the first day of preservation. On the other hand, MIF failed to keep C. parvum oocysts suitable for detection by DIFA even in the first day of preservation. From the above mentioned results, it was concluded that DIFA was more practical than the ordinary staining procedures, and DIFA of stool samples preserved in 10% formalin was the best laboratory diagnostic technique particularly for field and survey studies