Development of pulsed field gel electrophoresis and application for characterization and identification of Lactobacillus and Streptococcus thermophilus / 中华预防医学杂志

<p><b>OBJECTIVE</b>To develop a pulsed field gel electrophoresis (PFGE) method for molecular typing of Lactobacillus and Streptococcus thermophilus (S. thermophilus) and to apply it in identification and characterization of both bacteria isolated from yoghurt collected from Beijing supermarket.</p><p><b>METHODS</b>The five most useful restriction enzymes including Apa I, Not I, Sfi I, Xba I and Sma I were chosen to cut DNA of 52 strains of Lactobacillus, S. thermophilus as well as associated standard bacteria strains. The endonucleases and electrophoresis conditions for PFGE analysis were optimized and applied in molecular typing of Lactobacillus and S.thermophilus isolates. Cluster analysis based on the PFGE data was conducted. The identification results of PFGE were compared with those obtained in biochemical and 16s ribosomal RNA PCR identification tests.</p><p><b>RESULTS</b>Not I was suitable for L. bulgaricus, L. fermentum and L. delbrueckii digestion. While Apa I was an appropriate endonuclease for S. thermophilus, L. acidophilus and L. casei digestion. The results of molecular typing indicated that 24 strains of L.bulgaricus and 15 strains of S. thermophilus were grouped into 8 types by PFGE method, respectively. While 7 strains of L.acidophilus were grouped into 3 types and 2 strains of L. delbrueckii were grouped into 2 different PFGE types.</p><p><b>CONCLUSION</b>The results of PFGE analysis are in compliance with those of 16s rRNA PCR and biochemical identification. The PFGE method developed in this study is suitable for molecular characterization of both Lactobacillus and S. thermophilus.</p>

Natural occurrence of masked deoxynivalenol and multi-mycotoxins in cereals from China harvested in 2007 and 2008 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To elucidate the natural occurrence of masked deoxynivalenol (DON-3-G) and other multi-mycotoxins in cereals from parts of China.</p><p><b>METHODS</b>A total of 446 corn and wheat samples harvested in 2007 and 2008 collected from Henan, Hebei, Guangxi, Anhui, Sichuan, Chongqing and Jiangsu provinces were analyzed for DON-3-G and other multi-mycotoxins (including deoxynivalenol (DON), zearalenone (ZEN), nivalenol (NIV), et al) by UPLC-MS/MS.</p><p><b>RESULTS</b>Corn and wheat samples were mainly contaminated by DON and its derivatives as well as ZEN.88% (169/192) of wheat samples were positive for DON (range: 1.5 - 590.7 µg/kg; median: 30.8 µg/kg); 22.9% (44/192) of wheat samples were contaminated with ZEN (range: 1.7 - 3425.0 µg/kg; median: 8.0 µg/kg) and six samples contained ZEN concentration higher than the ZEN tolerance limit of 60 µg/kg. DON was detected in 50.5% (103/204) corn samples (range: 1.6 - 4374.4 µg/kg; median: 94.9 µg/kg); Seven samples contained DON exceeding the tolerance limit of 1000 µg/kg for DON. Additionally, ZEN was found in 41.7% (85/204) corn samples with the concentration between 1.6 µg/kg and 4808.7 µg/kg (median: 48.5 µg/kg) and there were 37 corn samples with ZEN level in the excess of tolerance limit for ZEN (60 µg/kg). DON-3-G was detected in corn and wheat samples for the first time in China with the median level of 21.4 µg/kg and 34.6 µg/kg for wheat and corn, respectively. Wheat was more heavily contaminated with DON-3-G than both 3-acetyl-DON (3-A-DON, median: 4.1 µg/kg) and 15-acetyl-DON (15-A-DON, median: 3.1 µg/kg) (t values were 5.111 and 5.966, respectively, both P values < 0.01). While, the level of 15-A-DON (median: 48.6 µg/kg) in corn was higher than 3-A-DON (median: 6.8 µg/kg) (t = -3.579, P < 0.01). The concentration of DON, DON-3-G, 3-A-DON, 15-A-DON and ZEN in corn were higher than that in wheat (Z values were -3.492, -1.960, -2.467, -8.711 and -6.272, respectively, all P values < 0.05). Wheat (median: 29.0 µg/kg) contained higher NIV in comparison with corn (median: 18.2 µg/kg, Z = -2.086, P < 0.05).</p><p><b>CONCLUSION</b>Wheat and corn samples from parts of China were contaminated with multi-mycotoxins and DON was the predominant;in comparison of wheat, corn was more heavily contaminated with DON, DON-3-G, 3-A-DON, 15-A-DON and ZEN.</p>

Efficacy and safety of arbidol in treatment of naturally acquired influenza / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of Arbidol in the treatment of naturally acquired influenza.</p><p><b>METHODS</b>A randomized, double-blinded, placebo controlled trial was conducted. Subjects were enrolled. The inclusion criteria included: aged 18 to 65 years, presented within 36 hours of onset of influenza symptoms; and had documented temperature of 37.8 degrees C or higher during an influenza outbreak in the community. Individuals were randomly divided Arbidol group (200 mg three times daily for 5 days) or placebo group.</p><p><b>RESULTS</b>Totally 232 individuals were recruited and received medication and follow-up. All of them were qualified to be analyzed for safety as intent-to-treat population (ITT) (113 Arbidol, 109 placebo). Twenty-two (9.48%) were during follow-up or refused to continue the trial, and 210 completed as schecule and identified as PP population (102 Arbidol, 108 placebo). Totally 125 individuals were identified as influenza-infected through laboratory test, which was defined as PPi population (59 Arbidol, 66 placebo). In PPi population, the cumulative alleviation proportion of Arbidol group was significantly higher than that of placebo group. The median duration of illness was 72.0 hours (95% confident interval (CI) 66.00-78.00 hours) in Arbidol group and 96.0 hours (95% CI 87.46-104.54 hours) in placebo group. The median area under the curve (AUC) of decreased total score were significantly higher in Arbidol group than in placebo group, which were 780.00 and 684.00 score-hours respectively. For PP population, similar results were seen. Adverse events reported were similar in Arbidol group and in placebo group. The main adverse events were gastrointestial symptoms and increased transaminase.</p><p><b>CONCLUSION</b>Arbidol was effective and well tolerated in the treatment of early naturally acquired influenza.</p>