Rapid Identification of Bacterial Species Associated with Bronchiectasis via Metagenomic Approach / 生物医学与环境科学（英文）

Bronchiectasis is a chronic lung disorder and a number of bacterial pathogens are involved. However, 30%-40% of sputum and purulent samples in good quality failed to grow any pathogenic bacteria, making it difficult to confirm the pathogen. In this study, we collected bronchoalveolar lavage fluid from a bronchiectasis patient undergoing acute exacerbation, and sent for 16S rDNA pyrosequencing by a 454 GS Junior machine. Metagenomic analysis showed the composition of bacterial community in sample was complex. More than a half of reads (51.3%) were from Pseudomonas aeruginosa. This result was corresponding with the culture result but came out 2 d earlier, which is meaningful for early diagnosis and treatment. The detection with 16S rDNA pyrosequencing technology is more sensitive and rapid than routine culture, and can detect the co-infection or symbiosis in airway, giving us a novel and convenient approach to perform rapid diagnosis.

Structural variation of the superintegron in the toxigenic Vibrio cholerae O1 El Tor / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To understand the genetic structures and variations of the superintegron (SI) in Vibrio cholerae isolated in the seventh cholera pandemic.</p><p><b>METHODS</b>Polymerase chain reaction scanning and fragment sequencing were used. Sixty toxigenic V. cholerae O1 El Tor strains isolated between 1961 and 2008 were analyzed.</p><p><b>RESULTS</b>Some variations were found, including insertions, replacements, and deletions. Most of the deletions were probably the result of recombination between V. cholerae repeat sequences. The majority of the variations clustered together. The SIs of the strains isolated in the 1960s and 1970s showed more diversity, whereas SI cassette variations in strains isolated in the 1990s and after were lower, with ∼24 kb signature sequence deletion. This indicates the predominant SI in the host during the epidemic in the 1990s and after. The insertion cassettes suggested the mobilization from the SIs of other V. cholerae serogroups and Vibrio mimicus.</p><p><b>CONCLUSION</b>The study revealed that structural variations of SIs were obvious in the strains isolated in epidemics in different decades, whereas the divergence was based on syntenic structure of SIs in these El Tor strains. Also, the continuing cassette flows in the SIs of the host strains during the seventh cholera pandemics were displayed.</p>

Influence regarding micro-ecological environment of Snail habitats in Lake area on the distribution of Snails / 中华流行病学杂志

Objective To explore the relationships between micro-ecological environmental factors and the density of Snails so as to provide information for the elimination of Snails and control of Schistosomiasis disease,under ecological methods.Methods A bottomland close to Junshan Park in Yueyang city,Hunan province was selected as the field for survey during 10,2007-10,2008,and a systematic sampling method was applied to determine the specific sites of Snail investigation.All the Snails in each frames were collected and the soil surface temperature and vegetation coverage in several frames were measured.30 g soil sample in each selected frames were also collected simultaneously.The number of live Snails in each frame was counted by dissection,and soil measured pH value and soil moisture were tested in the laboratory.The distribution of Snails and microecological environmental factors,fitted general additive model for the relationship of these factors and the Snail density were described.Results 104 frames were surveyed,with pH value as between 4.70-7.92,vegetation coverage as in 1% to 96%,soil surface temperature as in 14.5-32.7℃,the soil moisture as in 0.07-2.00.Under General additive model,data showed that there was no significant difference for vegetation coverage.However,other factors were all significantly different(P＜0.001).It was found that a nonlinear relationship was existing between these factors and the Snail density.Conclusion Smoothing function relationship was noticed between the Snail density and micro-ecological environmental factors.It's suggested to fit general additive model to study the relationship between the distribution of Snails and its influencing factors,so as to adopt appropriate measures to change the related ecology to control the diffusion and reproduction of Snails.

Metagenesis of intermediate host to Schistosoma japonicum Oncomelania snail in mountainous areas / 中华流行病学杂志

Objective To anderstand the metagenesis of Oncomelania snails in the mountainous regions so as to control the spread of snails and the epidemics of schistosomiasis.Methods Observation spot was established at a typical snail habitat close to Puge county,Sichuan province from February 2008 to July 2009.Random sampling was applied to determine the place of each frame during the observation.All the snails in each frame were collected and numbers counted in the laboratory,with the number of mating pairs in each frame also observed.Snails being collected were measured for the body indices and the dissection was carried out to identify gender composition.survival status and the number of live snails in each frame counted.Line graphs of the body indices.mating pairs in each observed months,bar graphs of the snail density,proportions of gender together with the maturity of the snails in each month were drawn.Results The number of live snail existed the whole year and its density fluctuated.All the three kinds of body indices showed the same time trend and a dynamic circulation.The young snail existed all year around and arose constantly in proportion from May,becoming the dominant snailin October to replace the adult snails.The young and adult snails also showed a dynamic alternative.The gender composition showed no significant difference during each month.The number of the mating pairs was more on April.May and June annually,when were the snail's main multiplying stage.Conclusion In mountain area.the young snails existed through all the year while adult snails appeared to be dominantin each month except for October.Oncomelania snail showed a circular process of metagenesis which started in May and finished in October.The snail population presented a dynamic equilibrium.It was concluded that ecological studies on Oncomelania snail were extremely relevant,either to optimally apply the existing control measures or to develop alternative measures for snail control,ecologically or biologically.

Simple sequence repeat variation and small-scale spatial autocorrelatian analysis on smooth-shell populations of Oncomelania hupensis in Sichuan province / 中华流行病学杂志

Objective To analysis the spatial autocorrelation on the small-scale distribution of the genetic variation in the population of Oncomelania hupensis in Puge county, Sichuan province, using simple sequence repeat (SSR) marker. Methods 5 pairs of SSR primer were used to amplify the genomic DNA of Oncomelania hupensis, and the alleles with frequency ranging from 15% to 85% were used to calculate Moran' s I spatial autocorrelation coefficients in 14 distance band based on equal numbers of paired samples. Results A total of 274 alleles were scored by 5 pairs of SSR primer, the average polymorphic information content of the 274 alleles were 0.965 which indicated a high level of genetic diversity. 39 alleles showed different patterns of positive spatial autocorrelation of genetic variation, which was non-random spatial structure. When the distance band increased, the spatial auto-correlativity decreased based on the average Moran' s I value at 14 distance band. The alleles which showed a negative spatial autocorrelation were not found in any distance band. Conclusion The spatial distribution of the genetic variation of SSR showed positive spatial autocorrelation in the population of Oncomelania hupensis, and the spatial auto-correlativity decreased with the increase of distance band.

Spatial distribution and elimination of Schistosome japonicum intermediate hosts Oncomelania hupensis in mountainous regions / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the spatial distribution and elimination of Oncomelania hupensis in mountainous regions.</p><p><b>METHODS</b>Puge County in Tezi township was selected as the study site and the quadratus were placed randomly to investigate snail. The two sods with water were selected as the sites of snail elimination. One sod with area of 1000 m2 and mean density of 9.88 snails/0.11 m2 was selected as the trial group with 'heaping' method, and the other with area of 1000 m2 and mean density of 9.80 snails/0.11 m2 as the control group with sprinkling method. The molluscacidal effect of the two methods was compared by systematic sampling (5 m x 5 m). The sample size was 40 quadratus.</p><p><b>RESULTS</b>The snail distributed mainly in the sods with water, canals and farmlands. Among the three snail habitats, the area with snail was the most in the farmlands with relatively lower density of living snail; the next was the sods with water, with relatively higher density of living snail. Before killing snails, the rate of quadratus with snails was 87.50% in the trial site, and 82.50% in the control site. The mortality of snails was 3.89% in the trial site, and 4.16% in the control site. After three months, no living snails were found in the trial site, while in the control site, the rate of quadratus with snails (chi2 = 0.31, P > 0.05) and the mortality of snails (chi2 = 3.12, P > 0.05) did not decrease significantly, and the density of living snails only reduced by 8.88%.</p><p><b>CONCLUSION</b>The 'heaping' method is an efficacious measure for snail control.</p>