ABSTRACT
Objective To investigate the genotype distribution of CTX-M-type extended-spectrum β-1actamase(ESBLs) by denaturing high-performance liquid chromatography(DHPLC) in Hunan Province and the accuracy of DHPLC assay. Methods The blaCTX-M genes of standard strains and clinical ESBLs-producing Enterobacteriaceae were amplified by multiplex PCR followed by DHPLC and genotype determination. 25 isolates randomly selected were sequenced to assess the accuracy of DHPLC method. Results Among 142 ESBLs-producing isolates, 109 isolates carried blaCTX-M gene (76. 8% ). Four different CTX-M genotypes were detected by DHPLC, including CTX-M-3 (33 isolates), CTX-M-15 (19 isolates), CTX-M-14 (52 isolates) and CTX-M-9 (5 isolates). The DHPLC typing of 25 isolates suggested that 24 isolates were verified uniformly by the sequencing, but one CTX-M-15 isolate typed by DHPLC was shown to be CTX-M-82 by sequencing. Conclusion DHPLC is a powerful tool for genotyping of the resistance gene and is worth being applied in the clinical and scientific research with accurate, rapid and economic advantages.
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Objective To understand the health effects and indoor air pollution caused by house decoration in Shizuichan city, Ningxia province. Methods 67 households which were newly decorated were chosen in the different districts of the city. 15days, one month, two months, three months, five months, six months after the decoration finished, formaldehyde, ammonia, benzene, radon in the indoor air were monitored and the questionnaire investigation was conducted. Results After two months, ammonia concentration reached the national standard limit. After 15 days, one month, two months, the rates of exceed limit of formaldehyde were 74.62%, 65.15% and 65.67% respectively, after 3 months ( in June), it was 90.62% and after 6 months, it was 71.21%. After 6 months, benzene concentration decreased slowly. The prevalence rates of throat, eye stimulation, fatigue and so on increased as the pollutants level increased. Conclusion In the investigated city, 6 months after the decoration finished, the indoor air pollution was still serious, which indicates it is not safe to move into those newly decorated rooms, even if after 6 months.
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15 mg/m3, 9.1% at CO concentration of
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Objective To study the safe drinking duration of purified drinking water of water dispensers, the relationship between the sanitary quality of purified drinking water and the structure of the water dispensers. Methods 30 drinking water dispensers were collected from the market and divided into 3 groups based on the structural types. A following-up experimental observation for the changes of the microbiological indexes of the water samples from the taps of water dispensers with different structures during the different prolongating operating period was carried out. Results The safe drinking duration was ≤ 4 days for the purified drinking water sampled from the taps of the water dispensers with common type at the normal atmospheric temperature and ≤ 14 day for water dispensers with bacterial inhibition type. The sanitary quality of the purified drinking water sampled from the taps of water dispensers was associated with the structural type of water dispensers, but not the brands of water dispensers. Conclusion The experimental results of the water samples collected from the taps of water dispensers with bacterial inbibition type at normal atmospheric temperature was better in quality than those of common type. The water dispensers with bacterial inhibition type provided with hygienic licence should be better recommended to choice.