饮用天然矿泉水微生物的检测及评述

对饮用天然矿泉水标准中的微生物指标的修订、发展趋势、意义及检验方法进行综述,并对梅州市附近10处饮用天然矿泉水水源采样进行了微生物指标检测及评述.按《饮用天然矿泉水检验方法》(GB/T8538-2008)对水样中的大肠菌群、粪链球菌、铜绿假单胞菌、产气荚膜梭菌四个指标进行检验,并按《饮用天然矿泉水》(GB8537-2008)进行评价.结果表明,所测水样中大肠菌群严重超标,粪链球菌、铜绿假单胞菌、产气荚膜梭菌均有1处超标,其它微生物指标达标.为了确保饮用天然矿泉水的质量,应加强水源的卫生监督管理.     

西藏发酵制品中拮抗酵母对水晶梨青霉病的防治效果研究

目的：从西藏发酵制品中分离筛选出对水晶梨采后青霉病具有较好防治效果的拮抗酵母,并对其作用机理进行研究。
　　创新点：首次从西藏发酵制品中筛选得到一株对水晶梨采后青霉病具有较好防治效果的拮抗酵母Rhodotorula mucilaginosa,并对其作用机理进行了初步研究。
　　方法：采用水晶梨果实体内筛选的方法,经过初筛与复筛,确定具有较好生防效果的拮抗酵母;通过对筛选所得拮抗酵母不同浓度、不同处理液的生防效果,果实伤口处生长动态,以及对梨果实采后品质影响的研究,初步探讨西藏发酵制品中拮抗酵母的生防作用机理。
　　结论：从西藏发酵制品中筛选得到一株拮抗酵母 R. mucilaginosa,其对水晶梨采后青霉病具有较好的生物防治效果。研究结果发现其主要作用机理为在果实伤口处与病原菌的营养与空间竞争。通过进一步研究,可开发为梨果实采后病害防治的新型生物保鲜剂。     

猪链球菌分离株的病原学特性

从病死猪体内分离到3株链球菌，并进行了病原学鉴定。细菌在形态上呈链球菌的特征，β或α溶血，分离株的生化试验结果相似，且都不与A～G链球菌群特异性血清发生凝集。经PCR鉴定。结果表明，3株均为猪链球菌2型。动物试验结果表明，3分离株对小鼠的毒力较低，但能在接种细菌12～15d后使小鼠发病致死。     

临床分离猪链球菌对常用抗菌药的敏感性

以金黄色葡萄球菌ATCC25923作为质控菌,用微量稀释法测定了7种药物对临床分离猪链球菌的体外最小抑菌浓度(MIC),以临床检验标准委员会(CLSI)的临界浓度作为判断标准,判定了猪链球菌对7种药物的耐药性;并分别在外排泵抑制剂氰氯苯腙(CCCP)、利血平存在的情况下,测定红霉素、泰乐菌素对分离菌MIC的影响.微量稀释法测定的MIC结果显示:临床分离的菌株以耐药菌为主,耐药谱型达11种;对磺胺间甲氧嘧啶(100%)耐药性最为严重,对红霉素(39.5%)、泰乐菌素(31.6%)、恩诺沙星(28.9%)、环丙沙星(28.9%)耐药性次之,而氟苯尼考和氨苄西林对所选菌株均敏感.在外排泵抑制剂存在时,抗菌药物对部分分离的耐药菌MIC下降,提示猪链球菌存在与抗菌药物耐药相关的主动外排机制.以上结果提示,国内分离的猪链球菌对临床常用的药物产生一定的耐药性,在临床选用药物进行治疗时,应充分考虑菌株的耐药性问题,以免延误病情造成治疗失败.     

产细菌素米氏链球菌S3的筛选及其细菌素生物学特征研究

从大连地区泡菜中分离到32株乳酸细菌,通过牛津杯法,从中筛选出1株有明显抑菌活性代谢产物的米氏链球菌S3.排除酸、过氧化氢等干扰因素后,离心发酵液对指示菌Micrococcus flavs ATCC28001仍有抑菌作用,用胰蛋白酶对其透析液处理后活性丧失,说明它们产生的抑菌物质是细菌素.以S,菌株为试材,对其细菌素类物质的产生及细菌素粗提物进一步研究,发现在对数末期其抑菌活性最高,对热相对稳定(100℃20 min),易被胰蛋白酶、蛋白酶K和胃蛋白酶失活,显示活性的pH值范围为4.0～5.5,粗提液表现为不仅抗藤黄微球菌属、枯草芽孢杆菌属、金黄色葡萄球菌属等革兰氏阳性菌,而且对大肠杆菌(E.coli)等革兰氏阴性菌也有一定抑制作用.说明S3菌株产生的是一类具有广谱抗菌作用的细菌素.     

Soil bacterial and fungal community successions under the stress of chlorpyrifos application and molecular characterization of chlorpyrifos-degrading isolates using ERIC-PCR

研究目的：评价毒死蜱施用后对土壤细菌和真菌群落结构的影响,并对降解功能菌株进行分析。创新要点：通过聚合酶链式反应–变性梯度凝胶电泳（PCR-DGGE）方法,揭示了毒死蜱施用后土壤细菌和真菌群落结构动态变化,并对试验土壤中的降解菌群进行分子鉴定。研究方法：将农田土壤用终质量分数5 mg/kg和20 mg/kg毒死蜱处理,同时以不施用毒死蜱为对照,定期采集土样进行毒死蜱残留测定并提取土壤DNA。将提取的土壤总DNA作为PCR反应模板,细菌群落结构分析采用对大多数细菌16S rRNA基因V3区具有特异性的引物GC-341F和517R,真菌群落结构分析采用ITS区特异引物对GC-ITS1f和ITS2f。DGGE图谱经Quantity One软件进行数字化分析,各泳道中的条带经标准化处理之后,条带的相对光密度构成一个矩阵,用Matlab软件进行主成分分析（PCA）,用Dice法计算相似性指数CS,用MEGA 4.1软件构建系统发育树,进行聚类分析。之后,采用LB、察氏和高氏三种培养基结合的纯培养分离方法,从毒死蜱处理土样中分离具有降解功能的菌株。分别提取纯培养物的染色体DNA,利用ERIC-PCR对分离到的降解菌进行基因组指纹图谱分析,将典型肠杆菌基因间的重复共有序列–聚合酶链式反应（ERIC-PCR）指纹图谱类型的代表菌株进行16S rRNA基因（细菌和放线菌）或ITS区（真菌）扩增并测序,测序结果提交GenBank基因库,并进行BLAST比对,初步确定降解菌株的分子地位。重要结论：本实验条件下,毒死蜱降解符合一级动力学,5 mg/kg和20 mg/kg毒死蜱浓度下的降解方程分别为y=5.252e-0.09x和y=19.41e-0.08x。DGGE指纹图谱显示,毒死蜱施用后土壤真菌群落结构与对照相比发生很大改变,且毒死蜱处理样品真菌群落结构保持基本稳定,多样性指数明显提高（见图2b）;主成分分析显示,毒死蜱处理样品与对照明显分在2个不同的区域,充分表明毒死蜱对土壤真菌群落结构影响迅速且持久（见图3b）。毒死蜱处理样品细菌群落结构只在试验前30天与对照相比明显不同,60天时已经恢复对照水平（见图2a）,同时主成分分析图上,毒死蜱处理样品与对照也越来越靠近,最后聚在一起（见图3a）,说明毒死蜱对土壤细菌群落结构影响短暂。最后,获得了9个典型的ERIC型毒死蜱降解菌株。     

A case of chylothorax treated curatively with Sapylin, a streptococcus preparation

Chylothorax is an uncommon disease where fatty fluid accumulates within the chest cavity. Conservative management, including repeated thoracentesis or pleurodesis, seems to be suitable to most cases. Herein, we present a case of efficacious pleurodesis by intrapleural injection of Sapylin, a streptococcus preparation, for the treatment of chylothorax. A 52-year-old non-smoking female farmer was diagnosed as idiopathic chylothorax after we ruled out possible causes including chest trauma, lymphoma, lung cancer, filariasis, tuberculosis, and etc. Two-time intra-thoracic injection of 3 Klinische Einheit （KE） Sapylin achieved rapid and effective control of chylothorax with no severe side effects. Sapylin may facilitate pleurodesis by producing a strong inflammatory response.     

Case Report:A case of chylothorax treated curatively with Sapylin, a streptococcus preparation

Chylothorax is an uncommon disease where fatty fluid accumulates within the chest cavity. Conservative manage- ment, including repeated thoracentesis or pleurodesis, seems to be suitable to most cases. Herein, we present a case of efficacious pleurodesis by intrapleural injection of Sapylin, a streptococcus preparation, for the treatment of chylothorax. A 52-year-old non-smoking female farmer was diagnosed as idiopathic chylothorax after we ruled out possible causes including chest trauma, lymphoma, lung cancer, filariasis, tuberculosis, and etc. Two-time intra-thoracic injection of 3 Klinische Einheit (KE) Sapylin achieved rapid and effective control of chylothorax with no severe side effects. Sapylin may facilitate pleurodesis by producing a strong inflammatory response.     

Academic alignment to reduce the presence of ‘social loafers’ and ‘diligent isolates’ in student teams

The acquisition of effective teamwork skills is crucial in all disciplines. Using an interpretive approach, this study investigates collaboration and co-operation in teams of software engineering students. Teams whose members were both homogeneous and heterogeneous in terms of their members' academic abilities, skills and goals were identified and compared. We describe the occurrence of ‘social loafing’, a well-reported phenomenon, in these teams. We also observed a phenomenon which we termed ‘diligent isolation’. Our assumption was that both of these can cause team dysfunction. Additional causes which became apparent during the research are listed. The article includes suggestions for improving team functionality.