One of the most important routes of transmission for Toxoplasma gondii infection is the ingestion of foods contaminated with cat feces containing sporulated oocysts. The diagnosis of T. gondii infection by fecal microscopy is complicated, as other similar coccidian oocysts are often present in the same fecal specimen. This study aimed to identify T. gondii oocysts in cat feces using a novel PCR technique. Feline fecal specimens (n = 254) were screened for coccidian oocysts by light microscopy using the Sheather's flotation method. PCR analysis performed on the same specimens targeted a 529 bp repeat element and internal transcribed spacer-1 (ITS-1) regions were used to confirm the presence of Toxoplasma oocysts. By light microscopy, 49/254 (19.3%) of specimens contained coccidian oocysts. PCR analysis demonstrated 2/254 (0.8%) and 17/254 (6.7%) positive results using Tox and ITS-1 primers, respectively. However, coccidian oocysts were not identified on microscopic examination of specimens that were PCR-positive by Tox primers. Coccidian oocysts were identified on microscopic examination of 6/17 (35.3%) of the PCR-positive fecal specimens using ITS-1 primers. The BLAST results of 16 ITS-1 sequences were identified as T. gondii (n = 12; 4.7%) and Hammondia hammondi (n = 4; 1.6%). There was slight agreement between the 529 bp and ITS-1 PCR results (κ = 0.148). This is the first report of the detection of Toxoplasma oocysts using PCR analysis on feline fecal specimens from Southern Thailand. The ITS-1 region has potential as an alternative marker to identify T. gondii oocysts in feline fecal specimens.
During 2009 to 2010, a total of 408 blood samples collected from malaria patients in Ranong (149) and Yala (259) Provinces, Thailand were investigated for Plasmodium spp using microscopic examination. There are no statistical differences in the prevalence of P. falciparum and P. vivax in samples collected from Ranong and Yala (46% vs 52%, and 54% vs 45%, respectively). Single nucleotide polymorphism of codon 86 in pfmdr1 (encoding P. falciparum multidrug resistance protein 1) was investigated among 75 samples of P. falciparum and 2 samples of P. knowlesi. A pfmdr1 N86Y mutation was detected in 1 out of 29 samples and 45 out of 46 samples obtained from Ranong and Yala Provinces, respectively. It is interesting that pfmdr1 was detected in two P. knowlesi DNA samples obtained previously from Ranong Province which was 99% homologous to pfmdr1 obtained from falciparum parasites in the same area but the mutation was not observed. The difference in multidrug resistance protein in Plasmodium obtained from those two border areas of Thailand will be of use in monitoring drug resistance in these border regions of the country.
Toxoplasmosis is one of the most common opportunistic parasitic diseases in patients living with HIV/AIDS. This study aimed to determine the seroprevalence of Toxoplasma infection in HIV-infected patients and to identify associated risk factors in Toxoplasma seropositive patients. This study was conducted at a regional public hospital in Hat Yai, southern Thailand during October 2009 to June 2010. Blood samples were collected from 300 HIV-infected patients. Each subject also answered a socio-demographic and risk factors associated with Toxoplasma infection. The prevalence of anti-Toxoplasma IgG antibodies in HIV-infected patients was 109 (36.3%), of which 83 (76.2%) had past infection and 26 (23.9%) had recently acquired Toxoplasma infection as indicated by their IgG avidity. Multivariate analysis using logistic regression showed that gender difference (adjusted OR = 1.69, 95% CI = 1.05-2.72) was the only factor associated with Toxoplasma infection. From the results obtained, these HIV-infected patients could be at high risk of developing clinical evidence of severe toxoplasmosis. Therefore, it is necessary to introduce primary behavioral practices to prevent Toxoplasma infection among HIV-infected patients.