Host-parasite Relations in Mouse Typhoid

Conversion of RpoS− Attenuated Salmonella enterica Serovar Typhi Vaccine Strains to RpoS+ Improves Their Resistance to Host Defense Barriers

The vast majority of live attenuated typhoid vaccines are constructed from the Salmonella enterica serovar Typhi strain Ty2, which is devoid of a functioning alternative sigma factor, RpoS, due to the presence of a frameshift mutation. RpoS is a specialized sigma factor that plays an important role in the general stress response of a number of Gram-negative organisms, including Salmonella. Prev...

A mouse model for the human pathogen Salmonella typhi.

Salmonella enterica serovar Typhi (S. Typhi) causes typhoid fever, a life-threatening human disease. The lack of animal models due to S. Typhi's strict human host specificity has hindered its study and vaccine development. We find that immunodeficient Rag2(-/-) γc(-/-) mice engrafted with human fetal liver hematopoietic stem and progenitor cells are able to support S. Typhi replication and pers...

Actinomyces bovis a possible cause for calcification of the parasite in the host tissue

Tracer Techniques for the Study of Host-parasite Relations

TRACER TECHNIQUES FOR THE STUDY OF HOST-PARASITE RELATIONS. Autoradiographic techniques have been used to study the interaction of many facultative and obligate parasites, including viruses. After feeding the host plant with labelled substrates, labelled material accumulates in the infected cells and seems to penetrate into structures of the parasite. After labelling the parasite, its influence...

Arginase Activity and Its Effects on Pathogenesis of Leishmania

  Leishmaniasis is a tropical parasitic disease that has become a major health challenge in many countries of the world. Not only has not been found any effective vaccine or treatment for the disease eradication, but also the advent of drug resistance is also increasing. Therefore, it is vital to take a precise attention to the physiochemical cycles of the Leishmania parasite and to identify i...