Background
Streptococcus suis infection in humans has received increasing worldwide recognition.Methods and Findings
A prospective study of S. suis infection in humans was conducted in Phayao Province in northern Thailand to determine the incidence and the risk behaviors of the disease in this region in 2010. Thirty-one cases were confirmed. The case fatality rate was 16.1%, and the estimated incidence rate was 6.2 per 100,000 in the general population. The peak incidence occurred in May. The median age of the patients was 53 years and 64.5% were men. Consumption of raw pork products was confirmed in 22 cases and the median incubation period (range) was 2 days (0–11) after consumption of raw pork products. Isolates from 31 patients were confirmed as serotype 2 in 23 patients (74.2%) and serotype 14 in eight patients (25.8%). The major sequence types (STs) were ST1 (n = 20) for serotype 2 and ST105 (n = 8) for serotype 14. The epidemiological analysis suggested three possible clusters, which included 17 cases. In the largest possible cluster of 10 cases in Chiang Kham and its neighboring districts in May, the source of infection in four cases was identified as a raw pork dish served at the same restaurant in this district. Microbiological analysis confirmed that three of four cases associated with consumption of raw pork at this restaurant were attributable to an identical strain of serotype 2 with ST1 and pulsotype A2.Conclusions
Our data suggest a high incidence rate of S. suis infection in the general population in Phayao Province in 2010 and confirm a cluster of three cases in 31 human cases. Food safety control should be strengthened especially for raw pork products in northern Thailand. 相似文献Purple or black rice (Oryza sativa L.) is a culturally important germplasm in Asia with a long history of cultivation in northern Thailand. Purple rice is identified by the color of the rice pericarp, which varies from purple to black with the accumulation of phenolic acids, flavonoids, and anthocyanins. In the present study, we assessed molecular variation within and between wetland purple rice landraces germplasm from northern and northeastern Thailand using 12 microsatellite loci. All purple rice varieties surveyed showed high levels of homozygosity within varieties and strong genetic differentiation among varieties, indicating the fixation of genetic differences among them. This pattern is consistent with purple rice farming practices in northern Thailand, where a small portion of harvested seed is selected and replanted based on farmers’ preferences. The reduced genetic diversity and high homozygosity observed for purple rice is also consistent with patterns expected for this inbreeding crop. Genetic differentiation among the varieties showed some degree of structuring based on their geographical origin. Taken together, these data highlight that the genetic diversity and structure of wetland purple rice landraces is shaped by farmer utilization and cultivation through local cultural practices, and that conservation should focus on ex situ conservation across its cultivation range, along with on-farm, in situ conservation based on farmers’ seed-saving practices. In situ conservation may prove especially valuable for preserving the genetic identity of local varieties and promote adaptation to local environments.
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