An initial survey of 150 horses from Thailand for anti-Pythium insidiosum antibodies.

INTRODUCTION: Pythium insidiosum causes a life-threatening infection termed pythiosis in humans and other animals. The organism has been identified in tropical and subtropical environments worldwide. Since 1985, human pythiosis has been increasingly reported from Thailand. Seroprevalence studies estimated that 32,000 Thai people had been exposed to the pathogen. In 2018, the first animal pythiosis case in Thailand was diagnosed in a horse. Here, we investigated the seroprevalence of anti-P. insidiosum antibodies in the Thai equine population. MATERIALS AND METHODS: We surveyed serum anti-P. insidiosum antibodies in 150 horses distributed across Thailand, using three established serological tests: enzyme-linked immunosorbent assay (ELISA), immunochromatographic test (ICT), and Western blot analysis. RESULTS: ELISA detected the anti-P. insidiosum antibodies in three horses. ICT and Western blot confirmed the presence of the antibodies in one of the ELISA-positive horses. Based on one positive out of 150 horses tested, the seroprevalence of anti-P. insidiosum antibodies in the Thai equine population was 0.7%, which is markedly higher than that in the Thai human population (0.07%), but much lower than that in the Brazilian equine population (11.1%). CONCLUSION: The seroprevalence of the anti-P. insidiosum antibodies in the equine population suggests a higher incidence of pythiosis in horses than in humans. The antibody surveillance reported by our group was undertaken to promote a better understanding of the epidemiology and host susceptibility of pythiosis in Thailand.

Molecular analysis of the iduronate-2-sulfatase gene in Thai patients with Hunter syndrome.

Molecular defects in the gene encoding the enzyme iduronate-2-sulfatase (IDS) result in Hunter disease (mucopolysaccharidosis type II, MPS II). To determine the molecular basis of MPS II in Thailand, the IDS gene was analysed in 20 Thai patients with Hunter syndrome from 18 unrelated families. A total of 19 different mutations, including 9 missense mutations, 3 nonsense mutations, 3 splice site alterations, 1 deletion, 2 indels, and 1 rearrangement were identified, 8 of which were novel (p.R101C, p.D148V, p.G224A, p.K227E, p.E254X, p.W337X, c.440_442delinsTT and c.720_731delinsTTTCAGATGTTCTCCCCAG). Evaluation of the IDS activity of two hemizygous variants identified in the same patient, p.R101C and p.R468Q, by expression of IDS with the individual mutations in COS 7 cells indicated that only the p.R468Q mutation affected IDS protein activity. Two exonic mutations, c.257C>T (p.P86L) and c.418G>A, were found to activate multiple cryptic splice sites, resulting in aberrantly spliced transcripts. Thus, MPS II in Thailand is caused by a diverse set of defects affecting both IDS protein production and activity.

Dietary intake of phytate, zinc and calcium of self-selected diets of Ubon Ratchathani and Bangkok subjects, Thailand.

The dietaty intakes of phytate, zinc and calcium of volunteers in Ubon Ratchathani (northeast Thailand) and Bangkok metropolitan were studied. The selected subjects were 10 men and 10 women from each area. The daily diets were collected for 5 consecutive days using duplicate portion technique. The diets were blended, aliquoted, mixed, freeze-dried and homogenized. Phytate was analysed by using ion exchange coupled with colorimetric method. Zinc and calcium were analysed by atomic absorption spectrophotometer. The total intakes of phytate were 1104.8 +/- 965.2 and 1139.3 +/- 481.1 mg/day for males and females in Ubon Ratchathani, 1304.7 +/- 956.2 and 997.1 +/- 435.1 mg/day for males and females in Bangkok. The zinc intakes were 20.0 +/- 8.8, 12.7 +/- 4.6, 7.7 +/- 1.8 and 6.1 +/- 1.2 mg/day for males and females in Ubon Ratchathani and for males and females in Bangkok, respectively. The calcium intakes were 524.6 +/- 259.9, 379.9 +/- 111.4 for males and females in Ubon Ratchathani and 366.5 +/- 150.5, 286.7 +/- 68.7 mg/day for males and females in Bangkok. The calculated phytate/zinc molar ratios were 7.5, 3.9 for males and females in Ubon Ratchathani and 16.2 and 17.5 for males and females in Bangkok. This study indicated that subjects from Bangkok have a phytate/zinc ratio higher than those in Ubon Ratchathani and higher than 12. This may effect the availability of some micronutrients such as zinc, calcium and iron. The daily intakes of zinc and calcium in these two groups were low compared to Thai RDA.