东亚飞蝗虫病原褪色沙雷氏菌的鉴定与检验北大核心CSCD

病原褪色沙雷氏菌的有效分离与鉴定对控制由褪色沙雷氏菌引起的养殖东亚飞蝗感染病均具有一定的参考与应用价值,同时将为对蝗灾的生物防治研究提供借鉴。对从发病死亡的养殖东亚飞蝗中分离的10株细菌,进行了表观分类学指征、16S r RNA基因序列与系统发育、人工感染的致病作用等方面的检验与分析。结果表明为沙雷氏菌属的褪色沙雷氏菌,对供试养殖东亚飞蝗显示强致病性。褪色沙雷氏菌对东亚飞蝗有强致病性,是蝗虫养殖的重要致病菌。     

东亚飞蝗虫病原褪色沙雷氏菌的鉴定与检验

病原褪色沙雷氏菌的有效分离与鉴定对控制由褪色沙雷氏菌引起的养殖东亚飞蝗感染病均具有一定的参考与应用价值,同时将为对蝗灾的生物防治研究提供借鉴。对从发病死亡的养殖东亚飞蝗中分离的10株细菌,进行了表观分类学指征、16S r RNA基因序列与系统发育、人工感染的致病作用等方面的检验与分析。结果表明为沙雷氏菌属的褪色沙雷氏菌,对供试养殖东亚飞蝗显示强致病性。褪色沙雷氏菌对东亚飞蝗有强致病性,是蝗虫养殖的重要致病菌。     

一株高产PLC的CW-W-90-3菌的鉴定

198 9年 ,筛选了 1株高产 phospholipaseC(PLC)的CW W 90 3菌株[1,2 ] ,据其形态特征、生理生化反应 ,初步将其归于弧菌科气单胞菌属[3 ] ,由于该菌株的许多生理生化特性与粘质沙雷氏菌相同。但其极生单鞭毛和无色素及少许生理生化特性与粘质沙雷氏菌相异。后经AutomatedBacteriaIdentificationSystem BiologMicroStationSystem检测 96种C源和N源的利用及其个体群体发育 ,说明其与粘质沙雷氏菌 (Serratiamarcescens)相符 ;并在基因组水平上研究该菌株的系统发育 ,从分子水平上对该菌株进行 16SrRNA序列分析煌同源性比较。根据CW W 90 3菌株 16SrRNA与GeneBank数据库中Serratiamarcescens的 16SrRNA的序列具有 99%的同源性 ,终将CW W 90 3菌株鉴定为粘质沙雷氏菌武汉株 (SerratiamarcescensWuhanstrain)。     

非OI群霍乱弧菌血清学分型系统的建立及初步应用

本文报道了非OI群霍乱弧菌血清学分型系统的建立。应用这一分型系统对我国广东、福建及河南三省分离的549株菌进行血清学定型。蓖株可分为55型。其中的优势型为VBO2、,及9。菌型的分布与分离地区有关。并发现有19个菌型是日本及美国分型系统所未包括的新菌型。血清的分型率为83．79％。对患者分离的菌株有较高的分型率。     

栖北散白蚁致病菌的分离鉴定与特性研究

[目的]了解散白蚁头部发红且死亡的原因,探究致病菌特性.[方法]从头部发红的散白蚁中分离菌株、培养并纯化,通过显微形态、革兰氏染色及16S rRNA基因序列分析鉴定菌株种类.进一步探究菌株产生红色素的条件并通过液相色谱和质谱联用等方法鉴定发酵产物.[结果]散白蚁鉴定为栖北散白蚁Reticulitermes speratus.从该白蚁头部分离得到一株产红色素的革兰氏阴性细菌RS.16S rDNA序列分析表明RS菌株为黏质沙雷氏菌Serratiamarcescens.RS菌株不同于其它大多黏质沙雷氏菌,在37℃仍然产生红色素.HPLC检测分析红色素为灵菌红素.[结论]本文首次报道从栖北散白蚁分离纯化一株产生灵菌红素的黏质沙雷氏RS菌,研究结果为灵菌红素的生产及散白蚁生物防治技术的研发提供了新的思路.     

空肠弯曲菌生物学分型的研究

用马尿酸水解,28℃中生长及10种试剂抗性试验,研究了空肠弯曲菌的生物学分型,每株菌按3种方法,4组实验进行计数,我们对86株弯曲菌进行了生物学分型,其中空肠弯曲菌79株,分为17种类型,结肠弯曲菌5株为5种类型,海鸥弯曲菌2株为2种类型。这对菌株在流行病学上分析有一定意义。     

东亚飞蝗肠道细菌的研究

目的从微生态学角度研究东亚飞蝗的营养生理活动。方法从东亚飞蝗自然种群的雌、雄成虫肠道环境中分离、纯化、培养,获得细菌16个属的菌株,对菌体形态、染色反应、培养性状、生理生化反应进行系统研究。结果上述16个细菌菌株分别属于沙雷菌属(Serratia)、短状杆菌属(Brachybacterium)、预研菌属(Yokenella)、肠杆菌属(Penterobacter)、微杆菌属(Microbacterium)、柠檬酸杆菌属(Citrobacter)、类芽胞杆菌属(Paenibacillus)、沙门菌属(Salmonella)、棍状杆菌属(Clavibacter)、放线杆菌属(Actinobacillus)、米勒菌属(Moelleralla)、不动杆菌属(Acinetobacter)、埃希菌属(Escherichia)、葡萄球菌属(Staphylococcus)、克吕沃尔菌属(Kluyvera)、克雷伯菌属(Kleb-siella)。结论东亚飞蝗雌性成虫肠道环境细菌种类为12个,雄性为10个,其中6个菌株相同;数量之间存在明显差异。     

金黄色葡萄球菌荚膜分型血清研制及初步应用

为了解中国金葡菌荚膜流行型,用5型和8型国际标准菌株的菌悬液免疫家兔,吸收除去交叉凝集素研制出金葡菌5型和8型荚膜分型血清,并应用于333株临床菌株荚膜分型。该血清效价为1：1280和1：640,与本菌及其它同型菌株玻片凝集反应呈强凝集,与其它型菌株不凝集,且与美国标准血清同时对333株临床分离菌株进行分型比较的符合率为100％。333株金葡地方菌株荚膜分型结果显示,8型菌株占绝对优势,所占百分率为70．9％;5型占6．3％,5型和8型菌株共占77．2％。这与国外金葡菌荚膜5型和8型占70％-80％的报道相似。试验为金葡菌疫苗株选择提供了流行病学依据。     

47株空肠弯曲菌湖北禽源株的多位点序列分型

【目的】为了解湖北地区家禽空肠弯曲菌的流行状况及其分子特征,应用多位点序列分型方法对2013–2014年的47株禽源空肠弯曲菌湖北分离株进行分子分型研究。【方法】以空肠弯曲菌的7个管家基因aspA、glnA、gltA、glyA、pgm、tkt和uncA为目的基因,提取样本基因组后PCR扩增,测序和分析。将测序结果上传数据库进行比对,制作成多位点序列分型(Multilocus sequence typing,MLST)遗传进化树。【结果】分离株共有38个ST型,10个克隆群,其中最多的克隆群为ST-353CC和ST-464CC,发现2个新的等位基因编号和25个新的ST型。遗传进化树显示,不同家禽宿主中空肠弯曲菌序列型存在一定的差异,不同地区和来源的空肠弯曲菌呈现出遗传多样性。【结论】本研究对湖北分离的47株禽源空肠弯曲菌进行了MLST分析,其结果显示菌株多样性较为丰富,将为我国家禽空肠弯曲菌的流行病学调查提供科学的数据。     

一起沙门菌引起的食源性疾病爆发的溯源分析

目的:对一起沙门菌引起的食源性疾病爆发进行溯源分析。方法:采用GB4789法对采集的样品进行分离及鉴定,采用16S r RNA基因分型方法及PFGE分型方法对分离的菌株进行分子生物学分析,并对爆发进行溯源分析。结果:生化及血清学结果表明,该起爆发分离的菌型为伦敦沙门氏菌。16S r RNA基因分型表明爆发所分离的菌株均为肠道沙门菌肠道亚种,菌株12 sam与其他4个菌株分子发育距离较远,均为16S r RNA基因分型的TYPE1-11型;PFGE分型结果表明菌株10 sam、16 sam、27 sam及29sam的PFGE带型相似度为100%,菌株12sam跟其他菌株相似率为96%。结论:GB4789法结果表明该起爆发是由伦敦沙门氏菌引起的,16S r RNA基因分型及PFGE分型方法的结果均表明该起食源性疾病来源一致。     

Effects of Serratia marcescens on the F1 generation of laboratory-reared Heliothis virescens (Lepidoptera: Noctuidae)

The effects of the bacterium Serratia marcescens (Bizio) was investigated on the F1 generation of laboratory-reared Heliothis virescens (F.). There was no difference in adult male or female longevity (i.e., parental generation) for individuals inoculated with S. marcescens as larvae (Serratia treatment) and those that were free of the bacterium (control treatment). However, the number of eggs laid and the prevalence of eclosion of eggs from Serratia treatment adults were reduced relative to control treatment adults. A very low number of F1 Serratia treatment eggs exhibited signs of infection, but a higher prevalence of mortality was observed for F1 larvae (n = 2,888) for the Serratia (3.5-4.6%) than for the control (1.1-1.5%) treatment. No S. marcescens was isolated from dead control larvae; whereas, 48 -54% of dead F1 larvae for the Serratia treatment were positive for the bacterium. However, there was no significant difference in larval weights between treatments. There were also no differences in either mortality or weight of F1 male pupae between treatments, but F1 female pupae were significantly smaller and prevalence of mortality was higher for the Serratia treatment. Serratia marcescens was not isolated from any of the control F1 pupae, but 6% of pupal cadavers for the Serratia treatment were positive for the bacterium. No S. marcescens was recovered from the meconia of any of the F1 adults (n = 2,600) regardless of treatment, and there were no differences in adult weights between treatments. Although sublethal effects of S. marcescens were detected, the impact and prevalence of the bacterium were tremendously reduced over the F1 generation in the absence of all but the most basic management strategies.     

Bacteriophage Typing of Clinically Isolated Serratia marcescens

A bacteriophage-typing scheme for the differentiation and classification of clinically isolated strains of Serratia marcescens was developed. Thirty-four Serratia bacteriophages were isolated from sewage and used to type 185 of 204 isolates (90.6%) of S. marcescens into 23 bacteriophage groups representing 71 types. Different bacteriophage types occurred at different intervals, suggesting that particular strains of S. marcescens are found at certain times. A correlation was found between inositol fermentation and bacteriophage type and between susceptibility to carbenicillin and bacteriophage type. However, there was no relationship between source of isolate and bacteriophage type. Bacteriophage typing of S. marcescens should provide a system which will aid in determining the origin of nosocomial Serratia infections.     

A note: gut bacteria produce components of a locust cohesion pheromone

AIMS: Faecal pellets from germ-free locusts were used as culture media to determine the ability of locust gut bacteria to synthesize phenolic components of the locust cohesion pheromone. METHODS AND RESULTS: Inoculation of germ-free faecal pellets with Pantoea agglomerans, a species commonly isolated from locusts, resulted in the release of large amounts of guaiacol and small amounts of phenol, both of which are components of the locust cohesion pheromone. Two other locust-derived species, Klebsiella pneumoniae pneumoniae and Enterobacter cloacae, also produced guaiacol from germ-free faecal pellets, but the opportunistic locust pathogen, Serratia marcescens, did not. The most likely precursor for guaiacol is the plant-derived vanillic acid, which is present in large amounts in the faeces of both conventional and germ-free locusts. CONCLUSIONS: These observations are consistent with previous ones, that locust gut bacteria are responsible for the production of components of the locust cohesion pheromone. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings illustrate how an insect can adapt to make use of a common bacterial metabolite produced by one or more of its indigenous gut bacterial species. This observation has implications for our appreciation of insect gut microbiota interactions.     

Diverse responses to UV-B radiation and repair mechanisms of bacteria isolated from high-altitude aquatic environments

Acinetobacter johnsonii A2 isolated from the natural community of Laguna Azul (Andean Mountains at 4,560 m above sea level), Serratia marcescens MF42, Pseudomonas sp. strain MF8 isolated from the planktonic community, and Cytophaga sp. strain MF7 isolated from the benthic community from Laguna Pozuelos (Andean Puna at 3,600 m above sea level) were subjected to UV-B (3,931 J m-2) irradiation. In addition, a marine Pseudomonas putida strain, 2IDINH, and a second Acinetobacter johnsonii strain, ATCC 17909, were used as external controls. Resistance to UV-B and kinetic rates of light-dependent (UV-A [315 to 400 nm] and cool white light [400 to 700 nm]) and -independent reactivation following exposure were determined by measuring the survival (expressed as CFU) and accumulation of cyclobutane pyrimidine dimers (CPD). Significant differences in survival after UV-B irradiation were observed: Acinetobacter johnsonii A2, 48%; Acinetobacter johnsonii ATCC 17909, 20%; Pseudomonas sp. strain MF8, 40%; marine Pseudomonas putida strain 2IDINH, 12%; Cytophaga sp. strain MF7, 20%; and Serratia marcescens, 21%. Most bacteria exhibited little DNA damage (between 40 and 80 CPD/Mb), except for the benthic isolate Cytophaga sp. strain MF7 (400 CPD/Mb) and Acinetobacter johnsonii ATCC 17909 (160 CPD/Mb). The recovery strategies through dark and light repair were different in all strains. The most efficient in recovering were both Acinetobacter johnsonii A2 and Cytophaga sp. strain MF7; Serratia marcescens MF42 showed intermediate recovery, and in both Pseudomonas strains, recovery was essentially zero. The UV-B responses and recovery abilities of the different bacteria were consistent with the irradiation levels in their native environment.     

粘质沙雷菌裂解性噬菌体ФSM9-3Y的分离和鉴定

目的从医院污水中分离粘质沙雷菌噬菌体,并分析其生物学特性,为进一步研究针对耐药性粘质沙雷菌的噬菌体制剂提供依据。方法采用双层琼脂平板法分离纯化针对粘质沙雷菌的裂解性噬菌体,观察噬菌体对宿主菌的裂解特异性,通过负染法电镜观察噬菌体的形态结构,提取噬菌体核酸进行酶切电泳,测定噬菌体的最佳感染复数和一步生长曲线,SDS-PAGE电泳初步分析噬菌体的结构蛋白和非结构蛋白。结果从医院污水分离出7株可裂解粘质沙雷菌的噬菌体,对其中一株噬菌体(命名为ФSM9-3Y)的生物学特征进行了初步研究。电镜显示噬菌体呈蝌蚪状,头部为20面体立体对称、直径约70 nm;尾部长约50 nm。ФSM9-3Y的最佳感染复数为1。一步生长曲线表明;ФSM9-3Y的潜伏期约30 min,暴发时间70 min,暴发量为629 PFU/cell。凝胶电泳显示噬菌体基因组为双链DNA、大小约54 kb。SDS-PAGE呈现至少包括13种蛋白,相对分子质量范围在25～130 kD,其中主要蛋白的相对分子质量约为48 kD。结论此次分离的噬菌体ФSM9-3Y为裂解性噬菌体,根据形态和结构特征,粘质沙雷菌噬菌体ФSM9-3Y属于有尾病毒目,肌尾噬菌体科。     

Premature Death in Parasitized Listronotus bonariensis Adults Can be Caused by Bacteria Transmitted by the Parasitoid Microctonus hyperodae

During experiments to determine the impact of the introduced parasitoid Microctonus hyperodae Loan (Hymenoptera: Braconidae) on the Argentine stem weevil Listronotus bonariensis (Kuschel) (Col.: Curculionidae), it was discovered that weevils frequently died prior to development of the parasitoid. It was postulated that this premature mortality could be caused by an ingress of pathogens in the puncture wounds created during parasitoid oviposition. This hypothesis was tested using the pathogenic bacterium Serratia marcescens Bizio as a model indicator of bacterial transmission by the parasitoid. When the bacteria were injected with a pin, simulating parasitoid attack, 92% of weevils died. Weevils exposed to parasitoids contaminated with bacteria suffered significantly higher mortality than those exposed to parasitoids untreated with bacteria. W hen parasitoids and weevils were confined in Petri dishes on filter paper contaminated with S. marcescens , there was significantly higher weevil mortality than in dishes without bacteria. The treatment of weevils, using the pin injection method, with bacteria isolated from weevils and soil ( Serratia spp., Bacillus spp. and Pseudomonas fluorescens (Trevisan)), produced similar levels of weevil mortality to the test strain. These results strongly suggest that parasitoid-mediated transmission of bacteria causing rapid death of the host can act as a significant mortality factor in biological control programmes, and should be considered in their interpretation.     

Clinical relevance and virulence factors of pigmented Serratia marcescens

Pigmented Serratia marcescens isolated in a Brazilian hospital were studied with respect to frequency of isolation, serotyping, antibiotic resistance and virulence factors. The serotype most frequent was O6:K14 (53%) and all isolates were resistant to ampicillin, cephalothin and tetracycline. The majority of the isolates (92%) were resistant to the action of human serum and all produced cytotoxins on Vero, CHO, HEp-2 and HeLa cells. These isolates were virulent for mice (LD(50)=10(7) bacteria ml(-1)) and showed virulence factors, but were isolated with low frequency (3. 4%) and caused infection in only 31% of cases. Analysis of serotyping, phage typing and chromosomal DNA revealed at least 13 unrelated strains among pigmented S. marcescens. In conclusion, this work describes a low frequency of isolation of pigmented S. marcescens from clinical specimens, indicating that non-pigmented strains are clinically more significant.     

改治结合,根除蝗害的关键因子是“水”!

改治结合,根除蝗害的关键因子是“水”。其主要原因为:(1)水灾是为东亚飞蝗创造发生地和转移到临近地区危害的关键因子;(2)东亚飞蝗产卵的适宜的土壤含水量为10%～20%(沙土为10%～12%,壤土为15%～18%,粘土为18%～20%);(3)先涝后旱,飞蝗成片;(4)黄(河)患是东亚飞蝗蝗害发生的源泉。南水北调东线工程的实施,有利于滨湖(库)蝗区东亚飞蝗的持续控制。     

Isolation of Serratia marcescens in the midgut of Rhodnius prolixus: impact on the establishment of the parasite Trypanosoma cruzi in the vector

The effects of resident bacteria in the stomach of 5th-instar larvae of Rhodnius prolixus on the erythrocyte lysis and Trypanosoma cruzi infection were studied. The bacteria population increased approximately 10,000-fold after feeding. Hemolysis rose to approximately 28% within 24h postfeeding and then linearly grew until day 4 attaining almost 100%. The number of surviving Y strain of T. cruzi in the stomach declined drastically, while the infection with Dm28c clone was maintained stable. Five days after feeding, few different types of bacterial colonies were obtained when stomach content suspensions were spread onto BHI agar plates. The hemolytic bacteria were isolated and identified as Serratia marcescens biotype A1a (referenced as RPH), which produces the pigment prodigiosin. In vitro experiments, comparing incubations of RPH with S. marcescens SM365, a prodigiosin pigment producer, and S. marcescens DB11, a nonpigment variant, as a control, with erythrocytes and T. cruzi demonstrated that: (i) at 30 degrees C, SM365 and RPH diminished the populations of Y strain, but not DM28c clone, and DB11 was unable to lyse both T. cruzi strains; (ii) at 0 degrees C, SM263 and RPH killed the flagellates, but DB11 did not; and (iii) all three strains of S. marcescens were able to lyse erythrocytes. These results suggest that S. marcescens trypanolytic activity from the SM365 and RPH strains is distinct from the hemolytic activity and that prodigiosin is an important factor for the trypanolytic action of the bacteria.     

西藏飞蝗蝗蝻群集迁移特性及其群集效应

西藏飞蝗Locusta migratoria tibetnsis Chen暴发成灾的重要原因之一是蝗蝻具有群集迁移危害习性。为阐明西藏飞蝗灾变的行为机制,为西藏飞蝗的监测预警和防治提供科学依据,利用视频跟踪技术测定了自然环境中西藏飞蝗蝗蝻群集迁移的运动速度、方向,建立自推进粒子模型模拟蝗蝻群集迁移行为,分析群集迁移效应。结果表明,①不同自然环境中的西藏飞蝗蝗蝻在群集迁移过程中,群体内个体的运动表现出定向集体运动,群集迁移速度为0.1256 m/s,0.2 m以内的个体蝗蝻方向趋向一致。沙滩、翻耕农田和草地蝗蝻群运动一致性参数均较高,分别为0.8502、0.7870和0.6987。②西藏飞蝗蝗蝻群由分散运动转变为群集迁移存在临界密度,密度较低时群体内个体分散运动,当蝗蝻密度达到12-15头/m²时,蝗蝻群体由分散运动转变为高度一致的群集迁移运动。③蝗蝻群通过群集迁移可以显著增加迁移距离,随机运动蝗蝻1 d扩展只有70-80 m,而群集迁移1 d最大距离可达2.5 km。蝗蝻群集迁移可以提高发现特别是远距离食物等资源的概率,使群体中更多的个体受益。④尽管未发现室外蝗蝻群存在先验个体,但模拟发现在群集迁移群体中,只需要少数先验个体（3%-5%）即可引导整个蝗蝻群运动。