Short mucin 6 alleles are associated with H pylori infection

AIM： To investigate the relationship between mucin 6 （MUC6） VNTR length and Hpylori infection. METHODS： Blood samples were collected from patients visiting the Can Tho General Hospital for upper gastrointestinal endoscopy. DNA was isolated from whole blood, the repeated section was cut out using a restriction enzyme （Pvu 11） and the length of the allele fragments was determined by Southern blotting. Hpylori infection was diagnosed by ^14C urea breath test. For analysis, MUC6 allele fragment length was dichotomized as being either long （〉 13.5 kbp） or short （≤ 13.5 kbp） and patients were classified according to genotype [long- long （LL）, long-short （LS）, short-short （SS）]. RESULTS： 160 patients were studied （mean age 43 years, 36% were males, 58% H pylori positive）. MUC6 PvuⅡ-restricted allele fragment lengths ranged from 7 to 19 kbp. Of the patients with the LL, LS, SS MUC6 genotype, 43% （24/56）, 57% （25/58） and 76% （11/46） were infected with Hpylori, respectively （P = 0.003）. CONCLUSION： Short MUC6 alleles are associated with H pylori infection.

生防绿针假单胞菌HT66中脂肽的鉴定与功能

【目的】脂肽(Lipopeptide,LP)是微生物合成的一类重要的生物表面活性剂,不仅影响细菌的生物学功能,还对多种植物和人类病原菌具有广谱的拮抗作用。然而至今未见绿针假单胞菌(Pseudomonas chlororaphis)中脂肽产物的报道。【方法】通过生物信息学手段预测绿针假单胞菌HT66中脂肽的氨基酸组成及顺序,构建脂肽合成基因缺失突变株HT66Δclp,根据突变株缺失代谢产物的UPLC/QTOF-MS信息验证预测结果,并研究了脂肽对该菌株的生长、吩嗪-1-甲酰胺(PCN)合成、生物膜形成和群集运动性的影响。【结果】预测菌株HT66的脂肽氨基酸顺序为L-Leu–D-Glu–D-allo-Thr–D-Val–L-Leu–D-Ser–L-Leu–D-Ser–L-Ile,通过比对野生型和突变株代谢产物的质谱信息确定该产物为黏液菌素(Viscosin);脂肽合成基因缺失后,菌株HT66的生长无明显变化,但其PCN合成、生物膜形成和群集运动性均有不同程度地下降。【结论】菌株HT66的脂肽产物为黏液菌素,对菌株的代谢、生物膜形成和运动性等生物学功能具有重要的调控作用。研究报道了绿针假单胞菌中一种脂肽分子的结构与功能,为研究其合成和调控机制及开发和应用奠定了基础。