植物狮子尾的化学成分

研究了药用植物狮子尾(Ehaphidophora hongkongensis)的化学成分。利用各种色谱技术进行分离纯化。从狮子尾全草分离得到了6个化合物:β-谷甾醇(1)、β-胡萝卜甙(2)、对羟基苯甲酸(3)、羽扇豆醇(4)、豆甾醇(5)、正十八酸(6)。     

香港巨牡蛎北方人工育苗技术的研

为使在南方进行适于在高温、低盐海区生长的香港巨牡蛎的育苗摆脱受气候影响和技术、设施条件限制造成出苗量极低的困境,研究并推出了在北方夏季进行香港巨牡蛎人工育苗技术。该技术通过强化亲贝营养和25℃以上高温促熟培育,来满足在北方进行香港巨牡蛎人工育苗的条件,并在不同盐度（15‰、20‰、25‰、30‰）和温度（18～21℃、25～28℃）下观察香港巨牡蛎性腺发育;通过合理控制幼虫密度（前期8～10个/ml,后期4～5个/ml）,严把饵料质量关（投喂新鲜无污染的单胞藻）,科学换水与充气,及时分级筛选幼虫等,克服了香港巨牡蛎南方育苗成功率低的技术难题,使育苗生产顺利进行。开展了牡蛎壳和栉孔扇贝壳两种附着基的采苗试验,选出了比较理想的采苗方法——牡蛎壳采苗,该方法提高了稚贝的附着变态率,其附着变态率达50%以上,促进了稚贝的生长和成活。育出了5mm以上的稚贝,单位水体出苗量在15×104粒/m3以上。     

浙江省369份淡、海水鱼香港海鸥型菌污染状况研究

目的 掌握浙江省淡、海水鱼中香港海鸥型菌污染状况，为防止食源性香港海鸥型菌痛的发生和流行提供科学依据。方法 用改良头孢哌酮麦康凯琼脂分离，API20NE鉴定香港海鸥型菌。K-B纸片扩散法作耐药性测定。通用引物扩增16S rDNA并与香港海鸥型菌HKU1株开展同源性比较。结果 369份样品检出香港海鸥型菌18株。阳性率为4．88％，其中，鲤鱼检出率为25．00％，草鱼的阳性率为10．26％，海水鱼以及鲫鱼、鲢鱼、扁鱼等淡水鱼中未分离出。分离的香港海鸥型菌16SrDNA序列与HKU1株仅相差1～2个碱基，同源性在99．6％～100．0％之间；18株菌对头孢拉定、万古霉素、甲硝唑、克林霉素、头孢哌酮完全耐药，对红霉素、亚胺培南、克拉霉素、氨曲南、庆大霉素、丁胺卡那霉素、三甲氧苄氨嘧啶、四环素、氯霉素、多粘菌素B、环丙沙星完全敏感，对头孢噻吩、胺苄西林、头孢曲松的耐药性分别为83．33％、61．11％和5，56％。结论浙江省存在香港海鸥型菌污染源，建议相关监督部门应加大这类产品的管理力度。防止香港海鸥型菌病在我省的发生和传播。     

不同养殖区香港牡蛎的化学组成及特征气味成分分析

目的：研究沿海地区不同养殖区香港牡蛎的化学组成及其特征气味成分,为香港牡蛎的加工与高值化利用提供依据。方法：测定广西钦州、广东阳江、广东湛江、广东汕头4 个养殖区香港牡蛎的一般营养成分、氨基酸、甜菜碱、重金属元素及微量元素、三磷酸腺苷及其关联化合物以及与气味相关的挥发性化合物的组成及含量。结果：钦州大蚝灰分、蛋白质和牛磺酸的含量最高,程村蚝糖原含量最高,湛江蚝水分、甜菜碱含量最高,汕头蚝脂肪和总糖含量最高;氨基酸总量最高的是钦州大蚝;5’-肌苷酸对牡蛎滋味影响最大;汕头蚝微量元素中铁、锌、铜含量最高;(E,Z)-2,6-壬二烯醛可显著影响程村蚝、钦州大蚝和湛江蚝气味,1-辛烯-3-酮可显著影响汕头蚝气味。结论：不同养殖区香港牡蛎呈味物质和挥发性成分各有特色,且营养成分、氨基酸、元素等含量有显著差异。     

香港海鸥型菌(Laribacter hongkongensis)的鉴定方法研究现状

香港海鸥型菌是从香港肝硬化病人体内分离得到的新细菌菌属，被认为是致腹泻病原菌。为给相关的研究提供参考，介绍香港海鸥型菌选择性培养基的筛选，生物学特征检测方法，基因序列分析检测方法中的16s rRNA寡核苷酸序列分析定性鉴定核糖分型(ribotyping)与脉冲电场电泳，自动化细菌鉴定系统。     

Identification and characterization of integron-associated antibiotic resistant Laribacter hongkongensis isolated from aquatic products in China

Laribacter hongkongensis is a recently discovered bacterium associated with gastroenteritis. In this study, a total of 199 isolates of this species obtained from aquatic products (n = 462) in Guangzhou City, China, were examined for their susceptibility to 19 antimicrobial agents and the presence of antimicrobial resistance integrons. The genetic relatedness of the isolates with integrons was also evaluated. A PCR-based method was used to screen integrons and found that 13 (6.5%) of the isolates harbored class 1 integrons. The antimicrobial resistance rates of integron-positive isolates were significantly higher than integron-negative ones for cefepime, ciprofloxacin, gentamicin, tetracycline, trimethoprim-sulfamethoxazole and rifampicin. Genetic sequence analysis revealed that these integrons contained various antimicrobial-resistance genes (dfrA1, dfrA14, dfrA17, dfrA32, aadA1, aadA2, aadA5, cmlA5, arr2, ereA and orfC) organized into different gene cassettes arrangements including a novel array of dfrA14-arr2-cmlA5. Pulsed-field gel electrophoresis (PFGE) yielded 13 different patterns among 13 integron-positive isolates, which could be grouped into four clusters. These indicate the dispersal of multi-resistant integrons among different molecular types. To the best of our knowledge, this is the first report showing distribution and characterization of class 1 integrons among L. hongkongensis isolates.     

2005年中国5个沿海省份鱼类产品中香港海鸥菌的污染调查

为初步了解中国鱼类产品中香港海鸥菌(Laribacter hongkongensisgen.nov.,sp.nov.)的污染情况,2005年8～10月对广西、广东、福建、浙江和河北5个沿海省份的水产品批发市场、零售市场和饭店采集的鱼类产品进行了香港海鸥菌的监测。在5省1097份鱼类样本中,草鱼247份、鲤鱼248份、其他淡水鱼431份和海水鱼171份。草鱼的检出率为7.69%(19/247),鲤鱼为0.81%(2/248),其他淡水鱼为0.23%(1/431),海水鱼中未检出(0/171)。我国沿海省份淡水鱼类产品中存在香港海鸥菌的污染,应加强对香港海鸥菌的监测。     

The prevalence, antimicrobial resistance and PFGE profiles of Laribacter hongkongensis in retail freshwater fish and edible frogs of southern China

Laribacter hongkongensis is a novel emerging pathogen associated with human gastroenteritis. We aimed to investigate the prevalence, antimicrobial resistance and genotypic relationship of 199 L. hongkongensis isolates from 690 intestinal samples of fish and frogs. These samples were collected from retail markets in the city of Guangzhou in southern China from October 2008 to September 2009. L. hongkongensis was detected in from 80 (16.3%) out of 490 freshwater fish, and this number included 76 (32.3%) out of 235 grass carp and 4 (14.8%) out of 27 bighead carp. A higher isolation rate of 59.5% (119 out of 200) was observed in edible frogs. The isolation rate was highest in the spring in comparison with other seasons. Notably, 63.8% of the isolates were resistant to at least one class of antimicrobial agents. Analysis by pulsed-field gel electrophoresis (PFGE) revealed that the isolates could be grouped into three clusters. Isolates from fish intestines were grouped into two clusters: cluster I and II. Isolates of frog-origin and several fish-origin isolates were grouped into cluster III. Two patient-derived strains could be classed into cluster III. Extensive genetic heterogeneity among the isolates was observed. The results indicate that L. hongkongensis isolates exhibits host tropism, extensive resistance to widely used antimicrobials and diverse biological evolution in an aquatic environment. The frog is more likely than the freshwater fish to be the potential source for human infection with L. hongkongensis.     

广西香港海鸥菌分离菌株脉冲场凝胶电泳分子分型研究

目的 探讨香港海鸥菌分子分型方法,了解广西水产品监测所分离的香港海鸥菌的相关性.方法 以NotⅠ限制性内切酶对2005年分离的香港海鸥菌酶切后进行脉冲电泳,用BioNumerics 5.1聚类分析获得电泳图谱.结果 7株香港海鸥菌分为6个分子型,其中从南宁分离的与从河池分离的2株香港海鸥菌高度同源,相似度达100％.结论 PFGE可应用于香港海鸥菌分子分型,有助于发现香港海鸥菌流行规律和传播途径,水鸟可能是香港海鸥菌传播环节的一种重要媒介.