特定底物技术快速检测水中大肠菌群相关指标

大肠菌群(Coliforms)、耐热大肠菌群(thermotolerant coliforms)和埃希氏大肠杆菌(E.Coli)都是判断水体是否存在粪便污染的重要微生物指标。文中介绍了一种特定底物技术可在 24h之内同时检测大肠菌群和埃希氏大肠杆菌数量,如果提高培养温度至44.5±0.2℃,则可检测耐热大肠菌群数量。     

新的《生活饮用水卫生标准》（GB5749-2006）与GB5749-1985相比主要变化

（1）水质指标由GB5749-1985的35项增加至106项，增加了71项；修订了8项；其中： （a）微生物指标由2项增至6项。增加了大肠埃希氏菌、耐热大肠菌、贾第鞭毛虫和隐孢子虫；修订了总大肠菌群；     

酶底物法在食品中大肠埃希氏菌MPN计数的应用研究

目的：探讨酶底物法在食品中大肠埃希氏菌MPN计数的应用,并对市售的2种酶底物试剂EC-MUG和科立得（Colilert）MMO-MUG进行比较。方法分别用两种酶底物试剂检测菌悬液和对6类食品大肠埃希氏菌MPN计数,同时用参考方法GB 4789.38—2012大肠埃希氏菌MPN计数检测,用McNemar’s检验对结果进行分析。结果 EC-MUG和科立得MMO-MUG酶底物检测菌悬液和6类食品的大肠埃希氏菌MPN计数,与参考方法比较,无统计学差异（χ2=0.01,P﹥0.05）。EC-MUG 和科立得 MMO-MUG 酶底物检测无统计学差异（χ2=0.01,P﹥0.05）;科立得 MMO-MUG酶底物检测结果易判断。结论酶底物法检测食品中大肠埃希氏菌MPN计数方便、快捷,有良好的应用前景。     

酶底物光谱法与酶底物法检测水中大肠菌群的比较分析

采用新型酶底物光谱法和酶底物法对不同类型水样中总大肠菌群、大肠埃希氏菌及粪大肠菌群指标进行同步检测。两种方法各有优势,采用SPSS软件对检测结果处理后进行配对t检验,结果显示：两组总大肠菌群的数据P=0.057,相关系数r=0.904;两组大肠埃希氏菌的数据P=0.593,相关系数r=0.972;两组粪大肠菌群的数据P=0.136,相关系数r=0.986,表明两种检测方法具有相关性,且没有统计学意义上的显著性差异。采用酶底物光谱法检测有证质控样品,总大肠菌群、大肠埃希氏菌、粪大肠菌群的检测结果均在质控样真值范围内,证明该方法检测准确度符合要求。酶底物光谱法与酶底物法相比,反应原理类似,操作更加简便,具有仪器自动化和智能化快速检测、判读、存储、联网传输数据等优点,可满足实验室常规检测需求,在应急突发事件现场检测方面有较强的运用前景和优势。     

污泥中粪大肠菌群菌值检测方法的改进

对污泥中粪大肠菌群菌值目前通用的多管发酵法进行优化。将污泥接种到乳糖胆盐发酵管,(44.5±0.5)℃培养24 h,阳性发酵管转种到EC培养液,(44.5±0.5)℃培养24 h,查MPN检索表,求倒数算出粪大肠菌群菌值,并与优化前的国标方法进行比对。结果表明,改进后的方法比国标方法减少了平板分离和染色镜检过程,缩短了检测时间,提高了检测结果的重现性,但两者在结果上无统计学意义上的差异。改进后的多管发酵法可以用于污泥中粪大肠菌群菌值的检测。     

受污染缢蛏大肠埃希氏菌的净化研究

本研究探讨了受污染缢蛏在海水理化特性:水温:22℃,pH:7.9,盐度:31.2 ppt,溶解氧:7.02 mg/L,颜色及透明度:无色透明;实验室室温:25℃,湿度:65%的条件下充气放养几天才能使大肠埃希氏菌完全净化。试验结果表明该缢蛏样品经过海水的暂养和净化,可以降低其大肠埃希氏菌和菌落总数的数量,而且暂养的时间越长,样品中大肠埃希氏菌和菌落总数的数量越少。     

大肠埃希菌和肺炎克雷伯菌临床分离株的耐药性分析

目的分析临床分离的大肠埃希菌和肺炎克雷伯菌的分布情况及耐药性。方法收集吉林大学中日联谊医院临床标本中分离的221株大肠埃希菌和152株肺炎克雷伯菌,采用纸片扩散法检测抗菌素的敏感性;双纸片协同试验和纸片表型确证试验筛选并确证产超广谱β-内酰胺酶的菌株;按照美国国家临床实验室标准化委员会(NCCLS)2005年版的标准判断结果。结果大肠埃希菌和肺炎克雷伯菌对亚胺培南和美罗培南的敏感性最高,均达100%;对头孢他啶、哌拉西林/他唑巴坦和头孢西丁的敏感性也较高,均大于70%,而对氨苄西林的耐药性均大于90%。共检出产超广谱β-内酰胺酶的大肠埃希菌118株,检出率为53.4%;肺炎克雷伯菌21株,检出率为13.8%;产超广谱β-内酰胺酶的两种菌株与非产超广谱β-内酰胺酶的同种菌株相比,对抗菌素的耐药性均明显增加。结论大肠埃希菌和肺炎克雷伯菌仍是产超广谱的β-内酰胺酶的主要菌株,且对常用抗菌素产生了较高的耐药性。     

益生菌对大肠埃希菌O157:H7的抑制作用

以11%脱脂牛奶和MRS肉汤作为培养基,在适宜大肠埃希菌O157:H7生长的条件(37℃,有氧)下,考察益生菌混合物对大肠埃希菌O157:H7生存生长的影响。前期实验获得了5株益生菌和大肠埃希菌O157:H7各自的生长曲线,确认了酸性条件(培养基pH值为3.8)对大肠埃希菌O157:H7的抑制作用。经过对酸性环境的适应并不能提高大肠埃希菌O157:H7菌株对益生菌的抵抗能力。大肠埃希菌O157:H7(37℃,有氧状态培养8 h)不能在经过益生菌有氧状态下培养后的培养基澄清液中存活,但将该澄清液的pH值调到6.5(新鲜MRS肉汤培养基的pH值),大肠埃希菌O157:H7又可以在其中生长。结果表明,高浓度的益生菌对大肠埃希菌O157:H7菌株有抑制作用,这一方面是由于益生菌降低了培养环境的pH值,另一方面也是由于益生菌本身在有氧状态下产生了抑制大肠埃希菌O157:H7的代谢产物。     

4种眼影微生物检验方法挑战性试验研究

目的:建立4种类型眼影微生物检验方法。方法:参照《化妆品安全技术规范》2015年版微生物检验方法和美国化妆品微生物测试USP51和USP61+62,对4种眼影(NOVO键盘指尖酷潮眼影星辰11#、希貝单色钻石眼影41#、希貝单色钻石眼影14#和希貝单色钻石眼影18#)进行菌落总数、霉菌和酵母菌以及金黄色葡萄球菌、铜绿假单胞菌和耐热大肠菌群进行挑战性试验。结果:计数方法中细菌总数采用1:20,1:100供试溶液1ml注皿,霉菌和酵母菌总数采用1:20供试溶液1ml注皿;控制菌(金黄色葡萄球菌、铜绿假单胞菌和耐热大肠菌群)均采用常规方法。结论:通过微生物挑战性试验,建立4种眼影微生物检验方法。     

食品能力验证中大肠埃希氏菌O157:H7的分离鉴定及质量控制

目的:从能力验证样品中分离、鉴定大肠埃希氏菌O157:H7,提高食源性致病菌的检测能力。方法:本文参照GB4789.36-2016《食品微生物学检验大肠埃希氏菌O157:H7/NM检验》对2份样品进行检测,对符合VITEK 2 Compact生化鉴定结果的进行血清学鉴定,同时使用荧光定量PCR方法进行联合检验分析。结果:2份能力验证样品均检出大肠埃希氏菌O157:H7,结果均为满意。结论:国标法与荧光定量PCR方法结合进行检测,相互验证,结果可靠性更高,准确性更强。同时在检验过程中应注意培养基、试剂的质量控制,灵活应用目标菌特异性提高检出率等。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。