C57BL/6 mice that are highly susceptible to infection with mouse hepatitis virus type 3 were protected against intraperitoneal viral infection by simultaneous intraperitoneal injection of Corynebacterium parvum. No protection was observed when C. parvum was given intravenously or when it was injected intraperitoneally 3 days before viral infection. Protective effects were, however, consistently...

background : cryptosporidium is an intracellular apicomplexan parasite that infects a wide range of vertebrates including humans. cryptosporidiosis is a major cause of diarrhea in children with and without human immunodeficiency virus (hiv) infection in developing countries. more recently, the molecular methods for identification of morphologically indistin­guishable species have been developed...

We have studied the interaction of Corynebacterium parvum and a variety of cell cycle-specific and cell cycle-nonspecific chemotherapeutic agents on granulocyte-macrophage progenitor cells [colony-forming units culture (CFU-c)] in C57BL/6 mice. In vitro tritiated thymidine suicide studies showed an increased rate of proliferation of bone marrow CFU-c 24 hr after C. parvum injection. In vivo tox...

A rapid detection method that is both quantitative and specific for the water-borne human parasite Cryptosporidium parvum is reported. Real-time polymerase chain reaction (PCR) combined with fluorescent TaqMan technology was used to develop this sensitive and accurate assay. The selected primer-probe set identified a 138-bp section specific to a C. parvum genomic DNA sequence. The method was op...

Host exploitation induces host defence responses and competition between parasites, resulting in individual parasites facing highly variable environments. Alternative life strategies may thus be expressed in context-dependent ways, depending on which host species is used and intra-host competition between parasites. Coitocaecum parvum (Trematode) can use facultative progenesis in amphipod inter...

The genotyping of numerous isolates of Cryptosporidium parasites has led to the definition of new species and a better understanding of the epidemiology of cryptosporidiosis. A single-locus genotyping method based on the partial sequence of a polymorphic sporozoite surface glycoprotein gene (GP60) has been favored by many for surveying Cryptosporidium parvum and C. hominis populations. Since ge...

A total of 477 faecal samples from pre-weaned sheep from 5 different farms in the south west of Western Australia were screened for the presence of Cryptosporidium and Giardia using PCR. There were substantial differences in prevalence between the farms and overall prevalence was 24.5% and 11.1%, respectively for Cryptosporidium and Giardia. At the 18S locus, 66 Cryptosporidium positives were i...

background : cryptosporidium parvum is a ubiquitous protozoan, which develops within the microvillous membrane of enterocytes in a wide variety of vertebrates, including man. cryptosporidiosis is an important parasite causing severe diseases in the immunodeficient people especially aids patients. cryptosporidiosis has been also reported as a com-mon serious primary cause of outbreaks of diarrhe...

To clear a Cryptosporidium parvum infection, mice need CD4+ T cells, major histocompatibility complex class II, and an intact CD40-CD154 signaling pathway. CD40 is constitutively expressed on marrow-derived cells such as dendritic cells and B lymphocytes and is induced by gamma interferon (IFN-gamma) on most somatic cells. To determine whether the CD40 needed to clear a C. parvum infection has ...

To assess the genetic diversity in Cryptosporidium parvum, we have sequenced the small subunit (SSU) rRNA gene of seven Cryptosporidium spp., various isolates of C. parvum from eight hosts, and a Cryptosporidium isolate from a desert monitor. Phylogenetic analysis of the SSU rRNA sequences confirmed the multispecies nature of the genus Cryptosporidium, with at least four distinct species (C. pa...