Two groups of rabbits, 10 animals each, were experimentally infected with varying doses of sporulated intestinal coccidia oocysts. The infectious material was composed of several rabbit intestinal coccidia oocyst species: Eimeria flavescens (7%), E. matsubayashi (9%), E. magna (12%), E. neoleporis (19%), E. perforans (21%) and E. media (32%). The third group of rabbits served as a control. Following the experimental infection, a subclinical form of the disease was induced in the rabbits while only 3 animals developed a full-blown disease with diarrhea. Shortly before and then on day 4, 7 and 10 after the infection, levels of the following blood enzymes were determined: creatin kinase, gamma glutamil transferase, amylase and alkaline phosphatase. A decrease in the activity of creatin kinase and a rise in the activity of amylase and alkaline phosphatase were registered. The activity of gamma glutamil transferase was within normal limits.
Cryptosporidium parvum and Isospora belli are coccidian protozoa responsible for significant gastrointestinal disease in patients infected with human immunodeficiency virus. The present study was designed to determine the prevalence of cryptosporidiosis and isosporosis in AIDS patients with chronic diarrhea in Thailand. Ninety-one patients from Siriraj Hospital and Bamrasnaradura Infectious Diseases Hospital were enrolled in this study. Of the 23 cases (25.3%) of cryptosporidiosis, 22 were diagnosed by modified acid-fast stain, whereas in another patient the diagnosis was made by histopathology. Isospora belli was found in 8 patients (8.8%) by simple smear and modified acid-fast techniques. With transmission electron microscopy, Cryptosporidium oocysts in fecal specimens were also identified.
The major surface antigen (P30) of the Toxoplasma gondii was expressed by an insect cell culture system infected with recombinant baculovirus. About 750μｇ of purified P30 (95％ purity) was obtained from a culture of 10 8 insect Sf21 cells. The recombinant P30 was used to immunize mice to induce immune response. Mice injected with the recombinant protein produced specific humoral and cellular immune responses. Immunization with P30 also prolonged the period of survival of mice infected by Toxoplasma parasites.
Trypanosoma evansi is morphologically indistinguishable from T. brucei. Close relationship between T. evansi and T. brucei was further documented by Gibson, Wilson and Moloo (1983), Masiga and Gibson (1990) and Stevens et al. (1992), suggesting that T. evansi is derived from T. brucei. However, T. evansi has been distinguished from T. brucei by their lack of maxicircle DNA, minicircle DNA homogeneity and lack of developmental stages in its insect vectors (Stuart 1983). Although several features of the minicircle DNA sequence have been reported to be specific for T. evansi (Masiga et al. 1990; Artama, Agey and Donelson 1992), we report here that two strains of T. brucei (T. b. gambiense Welcome and T. b. rhodesiense IL1501) also possess “the T. evansi specific” minicircle DNA sequence. Furthermore, Artama et al. (1992) have reported a similarity of PCR amplification patterns of the procyclic acidic repetitive protein (PARP), which is known to be a major surface protein of procyclic forms of T. brucei (Mowatt and Clayton 1987; Richardson et al. 1988), between T. evansi and T. brucei. In this study, we confirmed the existence of the similarity and suggested the use of the PARP primer as a diagnostic tool for the T. evansi infection. Although the PCR detection using this primer will not still distinguish the T. evansi infection from the T. brucei infection, it will be specially useful outside of the tsetse belt in where both the kinetoplastic and akinetoplastic strains of T. evansi are widely prevalent but not T. brucei. Moreover, the PARP A-α gene of T. evansi was sequenced, and the expression of the PARP gene in T. evansi was, for the first time, demonstrated by means of RT-PCR, although T. evansi is lacking the procyclic stage in its life cycle.