A Decade of Chronic Norovirus Infection Surveillance at the NIH Clinical Research Center: Clinical Characteristics, Molecular Epidemiology, and Replication.

Background: Noroviruses are an important viral cause of chronic diarrhea in immunocompromised individuals.

Method: We collected norovirus-positive stool samples (n=448) from immunocompromised patients (n=88) at the National Institutes of Health Clinical Research Center, U.S.

Host cell invasion and oral infection by Trypanosoma cruzi strains of genetic groups TcI and TcIV from chagasic patients.

Background: Outbreaks of acute Chagas disease by oral infection have been reported frequently over the last ten years, with higher incidence in northern South America, where Trypanosoma cruzi lineage TcI predominates, being responsible for the major cause of resurgent human disease, and a small percentage is identified as TcIV. Mechanisms of oral infection and host-cell invasion by these parasites are poorly understood. To address that question, we analyzed T.

Fibronectin-degrading activity of Trypanosoma cruzi cysteine proteinase plays a role in host cell invasion.

Trypanosoma cruzi, the agent of Chagas disease, binds to diverse extracellular matrix proteins. Such an ability prevails in the parasite forms that circulate in the bloodstream and contributes to host cell invasion. Whether this also applies to the insect-stage metacyclic trypomastigotes, the developmental forms that initiate infection in the mammalian host, is not clear.

Mammalian cell invasion by closely related Trypanosoma species T. dionisii and T. cruzi.

Protozoan parasites of the genus Trypanosoma can infect virtually all mammalian species. Within this genus, Trypanosoma dionisii from bats and Trypanosoma cruzi that causes Chagas' disease, belonging to the subgenus Schizotrypanum, can invade mammalian cells. The mechanisms of cell invasion by T.

Characterization of the infective properties of a new genetic group of Trypanosoma cruzi associated with bats.

A new genotype of Trypanosoma cruzi, associated with bats from anthropic areas, was recently described. Here we characterized a T. cruzi strain from this new genetic group, which could be a potential source of infection to humans.

Unique behavior of Trypanosoma dionisii interacting with mammalian cells: invasion, intracellular growth, and nuclear localization.

The phylogenetic proximity between Trypanosoma cruzi and Trypanosoma (Schizotrypanum) dionisii suggests that these parasites might explore similar strategies to complete their life cycles. T. cruzi is the etiological agent of the life-threatening Chagas' disease, whereas T.