Bovine carriers of Anaplasma marginale and Anaplasma bovis in South India

Carriers of bovine anaplasmosis in Northern Kerala, South India were detected using conventional microscopical and molecular techniques. PCR-RFLP and nested PCR techniques were used for detection of Anaplasma marginale and Anaplasma bovis respectively and the PCR products were confirmed by sequencing. Out of 150 samples tested, 25 were detected positive for A. marginale and five for A. bovis based on molecular tests. The inclusion bodies of A. marginale could be detected by microscopy in two blood smears after staining by giemsa while acridine orange staining detected three smears positive. The data clearly suggest the higher sensitivity of molecular techniques for diagnosis of these diseases.

IgG - Indirect fluorescent antibody technique to detect seroprevalence of Toxoplasma gondii in immunocompetent and immunodeficient patients in southern districts of Tamil Nadu.

Purpose: The purpose of the study was to determine the prevalence of Toxoplasma antibodies in selected immunocompetent and immunodeficient patients in and around Tirunelveli District of Tamil Nadu. Materials and Methods: This study was carried out from May 2006 to October 2007 in 175 immunodeficient and 175 immunocompetent patients. Serum samples were subjected into in-house IgG assay using indirect fluorescent antibody test (IFAT). Results: Out of 350 patients tested by IgG IFAT, 41 (11.71%) had antibodies for Toxoplasma gondii with a mean IFA titre of 43.42 ± 58.7 and the titre ranging from 1 : 16 to 1 : 256. Among the immunocompetent and immunodeficient groups, 19 patients (10.86%) and 22 patients (12.57%), respectively, had antibodies to T. gondii. Various risk factors associated within the study group was analysed and results were interpreted. Conclusions: The study has highlighted an overall seroprevalence of 11.71% with 12.57% in immunocompromised and 10.86% in immunocompetent patients respectively in a southern district, Tamil Nadu, which underlines the importance of screening of this parasite especially in the immunocompromised patients.

Usefulness of rabbits and mice as experimental laboratory models for Ehrlichia bovis.

Attempts were made to infect mice and immunosuppressed rabbits with Ehrlichia bovis. While evidence of infection could be noticed in rabbits, their identity as E. bovis needs confirmation. Mice appeared to be infected and showed clear inclusions in both blood monocytes and peritoneal macrophages. While symptoms of disease were not observable in rabbits, alopecia, dullness and death were noticed among infected mice. It is concluded that mice are better laboratory models for E. bovis infection; also that infection in mice could be enhanced by immunosuppression.