Effects of sampling time on polysaccharides of Dendrobium catenatum under temperature-controlled condition / 中国中药杂志

In order to reveal the accumulation trend of polysaccharides in Dendrobium catenatum and determine the effect of sampling time on polysaccharides, D. Catenatum D21 clone was harvested from January to December after culturing for 2 to 5 months in the growth chamber with constant temperature. Polysaccharides were determined by phenol-sulfuric acid method and the monosaccharide compositions were analyzed by pre-column derivative-UPLC. The results showed that the content of polysaccharide and its key component mannose was positively correlated with the culture time, but the contents of polysaccharides in all kinds of culture peaked from 5 to 6 months, which were consistent with the trend of field planting. The results suggested that the trend of polysaccharide accumulation in the plant could be related to the life rhythm of the sensory seasons of D. catenatum, which was significantly affected by the harvesting season, even under the constant condition of the culture chamber.

Distribution of genotypes in ESBLs producing E. coli strains isolated from posthepatitic cirrhosis' patients with bloodstream infection / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the genotype distribution of extended-spectrum beta-lactamases (ESBLs) in ESBLs-producing Escherichia coli (E. coli) isolates from posthepatitic cirrhosis' patients with bloodstream infection.</p><p><b>METHODS</b>E. coli were isolated in bloodstream from patients with posthepatitic cirrhosis between January and December in 2011. The strains were identified by VITEK-II. The antibiol susceptibility tests were performed with K-B method. beta-lactamases genes were detected multi-PCR, PCR, sequence and blast.</p><p><b>RESULTS</b>A total of 79 non-duplicate clinical isolates of E coli were consecutively collected from liver cirrhosis' patients with bloodstream infection. There were 20 isolates produced TEM-1 type beta-lactamases and 1 isolate produced SHV-1 typebeta-lactamases. 40 clinical isolates were detected to produce CTX-M type ESBLs, there were 20 CTX-M-1 group and 26 CTX-M-9 group, including 6 stains habouring both CTX-M-1 and CTX-M-9 group. Eight CTX-M genotypes were confirmed by sequencing of the PCR products, including CTX-M-3, CTX-M-14, CTX-M-15, CTX-M-24, CTX-M-28, CTX-M-31, CTX-M-65 and CTX-M-79.</p><p><b>CONCLUSION</b>CTX-M genotype ESBLs was the most popular extended-spectrum beta-lactamases in E. coli isolated from liver cirrhosis' patients with bloodstream infection. The CTX-M-14 is the dominant epidemic type.</p>