Objective The olfactory system plays an important role in mosquito behaviors such as blood sucking and oviposition site selection. This study compared the expression level of odorant receptor 10 gene ( OR10) in Aedes albopictus before and after blood sucking. Methods Reverse transcription-polymerase chain reaction (RT-PCR) was performed to amplify the OR10 gene, and quantitative real-time PCR was used to determine the expression levels of OR10 gene in male Ae. albopictus, and female Ae. albopictus before and after blood sucking. Results The open reading frame of the OR10 gene in Ae. albopictus obtained by amplification was 1 128 bp in length, encoding 376 amino acids. The amino acid sequence had an identity of 86.13% and 69.69%, respectively, with that in Ae. aegypti and Anopheles gambiae. The results of quantitative real-time PCR showed that male Ae. albopictus had the lowest expression level of OR10 gene of 1; female Ae. albopictus had a higher expression level (1.535±0.274) than male Ae. albopictus; female Ae. albopictus had the highest expression level of OR10 gene (2.284±0.203) after blood sucking; the expression level of OR10 gene in female Ae. albopictus changed significantly before and after blood sucking ( F=32.067, P=0.001). Conclusion The expression level of OR10 in Ae. albopictus changes significantly before and after blood sucking, which further proves that OR10 may be involved in the mosquito behavior of oviposition site selection after blood sucking.

Objective This paper was intended to analyze the spatiotemporal patterns of the Japanese encephalitis (JE) in Henan province from 2006 to 2010, and explore the connection between JE incidence and the geographical environmental driving factors. Methods The JE incidence from 2006 to 2010 in Henan was analyzed with epidemiological research, spatial autocorrelation, and correlation method. The multiple linear regression model was also built to identify the impact of meteorological, surficial and socio-economic factors on JE. Results The total number of JE case is 2 729 with yearly incidence of 0.547 4 per 100 thousand people and the overall death case was 119 with mortality rate of 4.36%. The incidence outbreak from July to September, accounting for 97.08% of the whole year cases and the annual incidence declined in 2008 and then fluctuated until 2010. JE cases were mainly concentrated in the southwest area, and "hot spots" agglomeration was significant in Luoyang, Nanyang, and northern Xinyang city. In terms of the meteorological driving factors, rainfall, the number of rainy days, >80% humidity days and >25℃ cumulated temperature promoted the outbreak of JE, while >30℃ cumulated days and the maximum above 30℃ cumulated temperature would reduce the incidence. For the surficial factors, watershed density and cultivated area illustrated the significant correlation with incidence of 99% confidence. With the increase of income per capita in farmers and total number of health technical staff, the possibility of an outbreak of JE also decreased. The overall predicted R² of regression model was 0.643 with the adjusted R² of 0.414. Conclusion The southwest area in Henan province is the key area for JE management. Research on the geographical driving factors of JE disease, will have a significant effect on the prevention and control of JE incidence.

Objective To determine expression and DNA-binding activity of the recombinant CRP (cyclic AMP receptor protein) in Yersinia pestis, Vibrio parahaemolyticus and Klebsiella pneumoniae for the study of transcriptional interregulation. Methods The coding region of the crp gene of Y. pestis, V. parahaemolyticus and K. pneumoniae was amplified by PCR, and cloned into the BamHⅠ and Hind Ⅲ sites of a pET28a vector. The recombinant plasmid pET28a-crp was inducted into BL21λDE3. Over-expression of His-CRP in the LB medium was induced by adding 1 mmol/L IPTG (isopropyl-b-D-thiogalactoside). The over-expressed protein was purified under native conditions with nickel loaded HiTrap Chelating Sepharose columns (Amersham). Electrophoretic mobility shift assay (EMSA) and DNase I footprinting experiments were carried out to analyze the DNA-binding activity of the three CRP proteins in vitro. Results All three purified His-CRP proteins were able to bind to the upstream DNA regions of Y. pestis (psaA), V. parahaemolyticus (toxR), and K. pneumoniae (kfuA). Conclusion Recombinant CRP proteins of Y. pestis, V. parahaemolyticus and K. pneumoniae were expressed and purified, suggesting their inter-regulatory effect on the transcription of key virulence genes of the three pathogens.

This study presents an overview of the current situation of the natural foci of plague in China and the research progress of genotyping of Yersinia pestis, as well as the impact on plague epidemiology  by the present socio?economic development and changes in the ecological environment in China. Corresponding prevention and control measures are proposed.

【Abstract】 Objective To discuss the influence factors of mice?to?mice plague in Yanchi county of Ningxia. Methods The density of field mouse was investigated by stratified sampling method. The mice were dissected and the viscera were taken out to do etiology examination by pressing culture method. The fleas collected were separated randomly into groups to do bacteriological analysis. Results During 2002-2006, the monitoring areas of Meriones unguiculatus plague accounted for 15.93% of total foci areas in Yanchi county. The average density of M.unguiculatus was 11.02/ hm2, and the infection rate of flea and the flea index were 34.17% and 0.85, respectively. Three indexes mentioned above were the highest in 2005 and 2006. There were 4633 field mice captured during 5 years, which belonged to 8 species 6 genus 4 family.  Sixty eight strains of Yersinia pestis were isolated including 57 strains from 3523 mice and 11 strains from 2393 fleas (about 380 groups). Conclusion M.unguiculatus and M.meridianus are the dominant species. Dipus sagitta, D.sibirica, Cricetulus barabensis and Phoodopus roborovskii are common species, and Cricetulus migratorius and Spermophilus dauricus are the rare species. The outbreak of mice plague has the positive correlation with mice density, infection rate of flea to mice and flea index. The projects about returning farmland to forests and pastures and forbidding grazing periodically increase the outbreak frequency and risk of mice?to?mice plague in the short time in Yanchi county.