Preliminary findings and molecular characterization of thin-walled Sarcocystis species in hearts of cattle and buffaloes in Thailand, Lao PDR, and Cambodia.

Cattle and buffaloes, popular protein sources worldwide, are intermediate hosts for several Sarcocystis species. These coccidian protozoans cause sarcocystosis resulting in subclinical and chronic infections in striated muscles by forming macrocysts or microcysts. In Thailand, Lao People's Democratic Republic, and Cambodia, Sarcocystis species have been reported, but molecular identification has been lacking. This study investigates the prevalence of infection, histo-morphology, and molecular identification of Sarcocystis species in hearts of cattle and buffalo sold in local markets. A phylogenetic tree inferred from a portion of the 18S ribosomal (r) RNA gene was used to identify the genus and species of Sarcocystis. The mitochondrial cytochrome c oxidase subunit 1 (cox-1 gene) was sequenced to confirm the species of host tissue. In Thailand, Sarcocystis was detected in 66.7% (14/21) of samples. In Lao People's Democratic Republic, 90% (9/10) of samples were infected and in Cambodia 100% (8/8). For the first time from these countries, we report Sarcocystis cruzi, Sarcocystis heydorni, and Sarcocystis levinei found in taurine cattle (Bos taurus) and water buffalo (Bubalus bubalis). Zoonotic protozoan transmission needs to be controlled by inspection activities by local health inspectors, and appropriate action is required at all points in the food chain by competent authorities to protect consumer health and prevent sarcocystosis in cattle and water buffaloes.

Molecular identification of microsporidian species in patients with epithelial keratitis.

Introduction. Ocular microsporidiosis is a significant emerging infectious disease reported in immunocompromised patients and immunocompetent persons throughout the world.Aim. To identify the pathogens responsible for human keratitis, via corneal scrapings.Methodology. Thirty-three hospitalized patients with epithelial keratitis were examined using staining and DNA sequencing. DNA was extracted from corneal samples and the small-subunit ribosomal RNA gene was amplified by polymerase chain reaction (PCR) and sequenced.Results. Twenty-one samples were positive by staining while PCR generated amplicons in 18 cases. Of the 18 sequences, 16 were identical with, or very similar to, those of Vittaforma corneae (99-100 % similarity) and the remaining two sequences were similar to that of unidentified Microsporidium species deposited in the GenBank.Conclusion. This study has reconfirmed that V. corneae causes epithelial keratitis in humans and that a newly detected Microsporidium species is also involved in microsporidial keratitis as one of the emerging pathogens in Thailand. Ophthalomologists should be aware of microsporidial keratitis in people from Thailand and those from neighbouring countries.

Altered Expression of Oxidative Metabolism Related Genes in Cholangiocarcinomas.

Cholangiocarcinoma (CCA) is a rare but highly fatal cancer for which the molecular mechanisms and diagnostic markers are obscure. We therefore investigated the kinetic expression of isocitrate dehydrogenase-1 (IDH1), isocitrate dehydrogenase-2 (IDH2) and homogentisate 1,2-dioxygenase (HGD) during the tumorigenesis of O. viverrini infection-associated CCA in an animal model, and confirmed down-regulation of expression in human cases of opisthorchiasis-associated CCA through real time PCR. Kinetic expression of HGD, IDH1 and IDH2 in the animal model of O. viverrini infection-induced CCA was correlated with human CCA cases. In the animal model, expression of HGD was decreased at all time points (p<0.01) and expression of both IDH1 and IDH2 was decreased in the CCA group. In human cases, expression of HGD, IDH1 and IDH2 was decreased more than 2 fold in 55 cases (70.5%), 25 cases (32.1%) and 24 cases (30.8%) respectively. The present study suggests that reduction of HGD, IDH1 and IDH2 may be involve in cholangiocarcinoma genesis and may be useful for molecular diagnosis.