对肿瘤有抑制作用的假单胞菌新种——济南假单胞菌

1973年自山东省无影山表土中分离出一株革兰氏阴性杆菌(编号161)。它对小鼠的宫颈癌、肝癌和黑色素瘤有明显抑制作用;对金黄色葡萄球菌、枯草芽孢杆菌和微球菌也有拮抗作用。     

济南假单胞菌新种的抗生作用

从济南土壤中分离、筛选到Ps 161菌株。该菌株为革兰氏阴性需氧短杆菌,具有激活非蒋异性细胞免疫和特异性体液免疫的功能,能使机体获得免疫应答和免疫反应性。其菌苗对小鼠精原细胞、鼠类移植瘤有显著抑制作用,并增强吡喹酮治疗小鼠血吸虫童虫的作用。能提高人体白细胞和体液免疫功能,对人体癌性胸水和表浅转移癌实体瘤有明显的消除与抑制效果。该菌株的代谢产物对革兰氏阳性细菌有显著抑制作用。 经中国科学院徽生物研究所鉴定,该菌株为一新种,命名为济南假单胞菌(Pseudomonas tnanenses sp. Nov.)。     

钌化合物对铜绿假单胞菌的光动力杀伤作用

【摘 要】 目的 探讨光动力疗法（PDT）对体外培养的铜绿假单胞杆菌的杀伤效应。方法 以多重耐药铜绿假单胞杆菌（P. aeruginosa）为对象,用457 nm和532 nm的激光作为光源,对不同浓度钌化合物孵育的细菌悬液进行光照,用菌落计数法观测PDT对铜绿假单胞杆菌的杀伤作用;同时观察了铜绿假单胞菌临床耐药菌与标准菌株对相同PDT作用的敏感性差异。结果 PDT处理组具有剂量－效应关系,在光照剂量相同的情况下,457 nm激光作为光源有更好的PDT杀伤效果;对多重耐药的铜绿假单胞菌,光动力同样有效,其作用甚至强于标准株。结论 钌化合物介导的光动力作用对体外培养的铜绿假单胞杆菌具有很强的杀伤作用,其效果和剂量关系密切。     

假单胞基因工程菌的开发应用现状与展望

假单胞菌 (Pseudomonas)是一群革兰阴性的杆菌或球杆菌 ,需氧生长 ,多数有鞭毛有动力。按照《伯杰氏系统细菌学手册》第二版 ,假单胞菌科包括 2 9个属 ,数百个种和亚种。假单胞菌广泛存在于自然界 ,是土壤和水体微生态系统的重要组成部分 ,也是自然界的碳、氮循环的重要组成部分[1] 。尽管其中的某些种如铜绿假单胞菌可引起人和动物的机会感染、个别种如丁香假单胞菌可某些农作物致病 ,但大多数种是无害的 ,某些假单胞菌和荧光假单胞菌还是植物生长的有益菌。更重要的是 ,假单胞菌拥有极为复杂的酶系统 ,具有非凡的降解能力 ,在环保方面意…     

铜绿假单胞菌感染的临床流行病学研究

目的研究铜绿假单胞菌(PA)在临床感染中的分布、耐药性变化、血清学分型及相关疾病特点,以配合院内感染监控工作的开展,指导临床合理用药,减少耐药菌株产生与传播,保护易感人群.方法回顾分析荆州市第二人民医院1995～2002年感染菌的实验室与临床病历资料.结果临床分离2 050株感染菌中,革兰阴性杆菌占首位为65.5%,其中非发酵革兰阴性杆菌为35.0%.PA位居第1位,分别占全部革兰阴性杆菌的15.8%和非发酵革兰阴性杆菌的45.1%.PA主要来自呼吸道(53.0%)与尿道(22.0%),以ICU病房多见(36.8%).在临床分离的感染菌中,PA检出率为0.35%,排列于大肠埃希菌、金黄色葡萄球菌和克雷伯菌属之后,位居第4位.PA对抗菌药耐药率呈上升趋势,常用广谱抗生素耐药已升高至19.0%～42.9%,敏感率较高的抗菌药依次为亚胺培南(81.0%)、阿米卡星(78.6%)、头孢他啶(77.4%)、哌拉西林(77.4%)、妥布霉素(76.2%)、头孢哌酮(75.0%)与环丙沙星(72.6%).PA血清型以1、3、6型为主,11型次之.感染者多有原发病及诱发因素,入侵途径以呼吸道与创伤为主,临床表现与预后随入侵途径与基础疾病不同而有异.结论 PA是医院感染主要致病菌,耐药率呈上升趋势,加强耐药性监测,合理使用抗生素,重视医疗器械消毒与医院环境卫生,控制易感人群感染,是预防PA感染、延缓菌株耐药的重要措施.     

重症监护病房鲍曼不动杆菌和铜绿假单胞菌的分布及耐药性监测

目的探讨医院重症监护病房(ICU)鲍曼不动杆菌及铜绿假单胞菌临床分离株的分布及耐药性特点。方法回顾性调查2006年7月至2010年6月ICU患者中分离出的鲍曼不动杆菌和铜绿假单胞菌的临床感染情况,对111株鲍曼不动杆菌和73株铜绿假单胞菌的药敏结果进行统计分析,所有数据采用WHONET 5.5软件进行分析。结果鲍曼不动杆菌及铜绿假单胞菌在呼吸道标本中检出率最高(76.1%),其次是CVP导管尖端(8.7%),鲍曼不动杆菌对临床常用抗菌药物耐药率85%的有8种,对亚胺培南的耐药率也达70.3%,耐药率最低的仅有头孢哌酮/舒巴坦(17.1%);铜绿假单胞菌对替卡西林、亚胺培南有较高的耐药率,分别为45.2%、41.1%,对其他抗菌药物耐药率均25%。结论下呼吸道是ICU患者鲍曼不动杆菌和铜绿假单胞菌感染的主要部位;ICU患者感染以鲍曼不动杆菌和铜绿假单胞菌为主,鲍曼不动杆菌较铜绿假单胞菌耐药及多重耐药性严重。     

铜绿假单胞菌体外抑菌活性研究

目的 观察铜绿假单胞菌抗菌物质对鲍曼不动杆菌等细菌的体外抑菌效果.方法 用交叉条带实验方法检测了铜绿假单胞菌对鲍曼不动杆菌、耐甲氧西林表皮葡萄球菌和粪肠球菌的体外抑制活性.结果 铜绿假单胞菌对鲍曼不动杆菌、耐甲氧西林表皮葡萄球菌和粪肠球菌体外抑菌活性良好,10株铜绿假单胞菌中,有8株对鲍曼不动杆菌的抑制率均达到了100％.另外有8株对耐甲氧西林表皮葡萄球菌的抑菌率均为100％;有6株对粪肠球菌的抑菌率为100％.结论 铜绿假单胞菌对上述3种致病菌具有较强的抗菌活性,具有开发前景.     

假单胞菌属的一个新种

从桔汁矿化水饮料中分离到一株编号为9191的革兰氏阴性短杆菌,其形态、生理生化特性与假单胞菌属已报道的种均不相同.该菌株具极生单鞭毛,氧化酶和触酶均阳性;O-F葡萄糖为非发酵型,不产生荧光色素,不产生脓菌素,不产生类胡萝卜色素,对葡萄糖呈碱反应.经类脂粒染色后细胞内可见PHB颗粒积聚.脲酶阳性,硝酸盐还原阳性,反硝化阴性;不水解淀粉和明胶,精氨酸双水解酶阴性;41℃下不生长,在麦康凯和SS平板上不生长.在0.85%CaCl_2的牛肉汤中不生长;利用β-羟基丁酸作为唯一碳源;DNA中G+C含量为65.15mol%.因此定为假单胞菌属中的一个新种.根据其对生理盐水敏感的特性,命名为盐敏假单胞菌(Pseudomonas halosensibilis Zou ＆ Cai nov.sp.).     

泡囊假单胞菌的分离及鉴定

从一例心包积液患者的心包液中,分离到一株氧化代谢、氧化酶阳性,具单极毛运动的革兰氏阴性杆菌。经形态、生理生化特性鉴定,DNA的G+C mol％测定和Biolog自动系列的验证,确认为泡囊假单胞菌(Pseudomonas vesieularis)。指出该菌可使免疫力低下患者发生感染。对该菌分类地位的变迁进行了讨论。     

铜绿假单胞菌必需基因的研究进展

铜绿假单胞菌为专性需氧非发酵革兰氏阴性杆菌,是医院感染的常见条件致病菌之一,可引起呼吸道、泌尿道、烧伤创面和菌血症等严重感染。铜绿假单胞菌耐药形势日益严峻,给临床治疗带来困难。必需基因是生长过程中必不可少的看家基因,对铜绿假单胞菌必需基因进行深入研究,不仅有助于了解细菌的生长、毒力等基本特性,也有助于筛选新的抗菌药物靶标。本文针对铜绿假单胞菌及其必需基因进行综述,首先介绍了铜绿假单胞菌的基本生理特性及目前耐药趋势,又归纳了必需基因的研究方法,最后对铜绿假单胞菌必需基因的研究进展进行总结。     

嗜热菌的耐热L—乳酸脱氢酶的研究

About 200 strains of extreme thermophilic bacteria were isolated from hot springs in Guandong province. A strain, HG25, was found to produce thermostable intracellular L-lactate dehydrogenase (EC. 1.1.1.27). It has the characteristic of Thermus sp. The cells were gram-negative, non-sporulating, nonmotile, aerobic rods containing yellow pigment. The optimum temperature for growth was between 65 degrees C to 75 degrees C, the maximum 85 degrees C, and minimum 40 degrees C. The generation time at the optimum was about 80 min. Starch was not hydrolyzed. Acid was not produced from glucose. The G+C content in DNA was 62-65 mol% (Tm). As the properties of strain HG25 is similar to those of Thermus aquaticus and T. thermophilus HB 8 belonging to the genus Thermus. The thermostable L-lactate dehydrogenase was partially purified by ammonium sulfate fractionation and DEAE-cellulose column chromatography. For pyruvate reduction, the optimum temperature of the enzyme was 60 degrees C and pH 8.0. After incubation in 0.1 mol/L phosphate buffer pH 7.4 at 70 degrees C for 10 min, the enzyme retained about 85% of its original activity. The half-live time (t1/2) at 85 degrees C was 10 min.     

Isolation and growth of a Pseudomonas species that utilizes cyanide as a source of nitrogen

A simple method of isolating bacteria that utilize cyanide as a source of nitrogen for growth has been developed. This involved supplying hydrogen cyanide as a vapour to glucose-containing minimal-salts agar plates. The bacteria isolated were Gram-negative, oxidase-positive rods producing a fluorescent green pigment and were tentatively identified as strains of Pseudomonas fluorescens. Three organisms were studied further and shown to be P. fluorescens biotype II. One of these (NCIB 11764) was grown in a glucose-containing fed-batch culture with either NH4Cl or KCN as the limiting nutrient. Cyanide-grown bacteria produced stoichiometric amounts of ammonia from cyanide when pulsed with cyanide under aerobic conditions. Stimulation of oxygen uptake was seen on addition of cyanide to suspensions of cyanide-grown but not ammonia-grown bacteria.     

Microbial diversity of soil from two hot springs in Uttaranchal Himalaya

Soil samples collected from two hot springs, Soldhar and Ringigad, both located in the Garhwal region of Uttaranchal Himalaya were analysed for their physical, chemical and microbial components. The alkaline pH, total absence of carbon and nitrogen, and high temperature were features common to soil samples from both sites. The Soldhar samples contained higher amounts of Cu, Fe and Mn. Ringigad soil was devoid of Cu, but had much higher phosphate. While the optimum incubation temperature for isolating the maximum microbial counts from soil samples from the two sites was 50 degrees C, microbial growth in broth was also observed when incubated at 80 degrees C. Microscopic examination revealed three types of microbial populations, i.e., bacteria, yeast and filamentous organisms. The soil samples were found to be dominated by spore forming rods. Out of 58 aerobic isolates, 53 were gram positive bacilli. Gram positive anaerobic oval rods were also observed up to 60 degrees C. Soil dilution plates revealed the presence of antagonistic and phosphate solubilizing populations.     

Cyanide production by Pseudomonas fluorescens and Pseudomonas aeruginosa

Of 200 water isolates screened, five strains of Pseudomonas fluorescens and one strain of Pseudomonas aeruginosa were cyanogenic. Maximum cyanogenesis by two strains of P. fluorescens in a defined growth medium occurred at 25 to 30 degrees C over a pH range of 6.6 to 8.9. Cyanide production per cell was optimum at 300 mM phosphate. A linear relationship was observed between cyanogenesis and the log of iron concentration over a range of 3 to 300 microM. The maximum rate of cyanide production occurred during the transition from exponential to stationary growth phase. Radioactive tracer experiments with [1-14C]glycine and [2-14C]glycine demonstrated that the cyanide carbon originates from the number 2 carbon of glycine for both P. fluorescens and P. aeruginosa. Cyanide production was not observed in raw industrial wastewater or in sterile wastewater inoculated with pure cultures of cyanogenic Pseudomonas strains. Cyanide was produced when wastewater was amended by the addition of components of the defined growth medium.     

Cyanide production by Pseudomonas fluorescens and Pseudomonas aeruginosa.

Of 200 water isolates screened, five strains of Pseudomonas fluorescens and one strain of Pseudomonas aeruginosa were cyanogenic. Maximum cyanogenesis by two strains of P. fluorescens in a defined growth medium occurred at 25 to 30 degrees C over a pH range of 6.6 to 8.9. Cyanide production per cell was optimum at 300 mM phosphate. A linear relationship was observed between cyanogenesis and the log of iron concentration over a range of 3 to 300 microM. The maximum rate of cyanide production occurred during the transition from exponential to stationary growth phase. Radioactive tracer experiments with [1-14C]glycine and [2-14C]glycine demonstrated that the cyanide carbon originates from the number 2 carbon of glycine for both P. fluorescens and P. aeruginosa. Cyanide production was not observed in raw industrial wastewater or in sterile wastewater inoculated with pure cultures of cyanogenic Pseudomonas strains. Cyanide was produced when wastewater was amended by the addition of components of the defined growth medium.     

Isolation and characterization of Pseudomonas brassicacearum J12 as an antagonist against Ralstonia solanacearum and identification of its antimicrobial components

A bacterial strain, J12, isolated from the rhizosphere soil of tomato plants strongly inhibited the growth of phytopathogenic bacteria Ralstonia solanacearum. Strain J12 was identified as Pseudomonas brassicacearum based on its 16S rRNA gene sequence. J12 could produce 2,4-diacetylphloroglucinol (2,4-DAPG), hydrogen cyanide (HCN), siderophore(s) and protease. The maximum growth and antagonistic activity were recorded at 30°C and pH 8. Glucose and tryptone were used as the most suitable carbon and nitrogen sources, respectively. Strain J12 significantly suppressed tomato bacteria wilt by 45.5% in the greenhouse experiment. The main antimicrobial compound of J12 was identified as 2,4-diacetylphloroglucinol (2,4-DAPG) by HPLC-ESI-MS analysis. The gene cluster phlACBD, which is responsible for 2,4-DAPG production, was identified and expressed in the bacterial strain Escherichia coli DH5α.     

Factors affecting antagonism of the growth of Phanerochaete chrysosporium by bacteria isolated from soils

Bacteria from polluted and agricultural soils antagonize the growth of Phanerochaete chrysosporium on solid media. The antagonistic bacteria in a soil contaminated with trinitrotoluene included fluorescent pseudomonads. Antagonism by fluorescent pseudomonads was variable according to the pH, and carbon and nitrogen sources used in the growth medium. A fluorescent siderophore produced by a Pseudomonas putida strain did not inhibit the growth of Phanerochaete chrysosporium but pseudomonad isolates capable of producing phenazine derivatives were strongly inhibitory.Utah Agricultural Experiment Station paper no. 4416     

Biological control of apple blue mold with Pseudomonas fluorescens

Pseudomonas fluorescens isolate 1100-6 was evaluated as a potential biological control agent for apple blue mold caused by Penicillium expansum or Penicillium solitum. Both the wild-type isolate 1100-6 and a genetically modified derivative labeled with the gene encoding the green fluorescent protein (GFP) were compared. The P. fluorescens isolates with or without GFP equally reduced the growth of Penicillium spp. and produced large zones of inhibition in dual culture plate assays. Cell-free metabolites produced by the bacterial antagonists reduced the colony area of Penicillium isolates by 17.3% to 78.5%. The effect of iron chelate on the antagonistic potential of P. fluorescens was also studied. The use of iron chelate did not have a major effect on the antagonistic activity of P. fluorescens. With or without GFP, P. fluorescens significantly reduced the severity and incidence of apple decay by 2 P. expansum isolates after 11 d at 20 degrees C and by P. expansum and P. solitum after 25 d at 5 degrees C when the biocontrol agents were applied in wounds 24 or 48 h before challenging with Penicillium spp. Populations of P. fluorescens labeled with the GFP were determined 1, 9, 14, and 20 d after inoculation at 5 degrees C. The log CFU/mL per wound increased from 6.95 at the time of inoculation to 9.12 CFU/mL (P < 0.05) 25 d after inoculation at 5 degrees C. The GFP strain did not appear to penetrate deeply into wounds based on digital photographs taken with an inverted fluorescence microscope. These results indicate that P. fluorescens isolate 1100-6 could be an important new biological control for apple blue mold.     

Temperature-induced alanine oxidation in a psychrotrophic Pseudomonas.

A psychrotrophic pseudomonad isolated from iced fish oxidized alanine at temperatures close to 0 degrees C and grew over the range 0 degrees C-35 degrees C. The rate of oxidation of alanine, measured manometrically, by cells grown at 2 degrees C was lower than that of cells grown at 22 degrees C. However, the consumption of oxygen after heat treatment at 35 degrees for 35 min was reduced considerably by 2 degrees C grown cells. Alanine oxidase activity was tested in an extract from cells grown at 2 degrees C and 22 degrees C with alanine as the sole carbon, nitrogen, and energy source. Cells grown at 2 degrees C produced an alanine oxidase with a temperature optimum of 35 degrees C and pH optimum of 8, which lost about 80% activity by heat treatment at 40 degrees C for 30 min. There was no change in activity after dialysis at pH 7, 8, or 9. Extracts from cells grown at 22 degrees C contained an alanine oxidase system with an optimum temperature of 45 degrees C, a pH optimum above 8, and only about 30% reduction of activity after heat treatment. This enzyme activity was concentrated in the 0.5 M elution fraction from a Sephadex column, and dialysis reduced the activity at pH 7 and 8. Mesophilic enzyme synthesis apparently started around a growth temperature of 10 degrees C. The crude alanine oxidase systems of Pseudomonas aeruginosa derived from cells grown at 13 degrees C and 37 degrees C had a common optimum temperature of 45 degrees C. These data suggest that one mechanism of psychrophilic growth by psychrotrophic bacteria may be the induction of enzymes with low optimum temperatures in response to low temperature conditions.     

孔雀石绿脱色菌恶臭假单胞菌菌株M6的分离、鉴定及其生长特性研究

从养殖池污泥中分离了6株对孔雀石绿具有脱色能力的菌株, 经过进一步在孔雀石绿营养肉汤中富集培养及其脱色率的比较, 筛选出对孔雀石绿具有较强脱色能力的优良菌株M6。菌株M6在30°C、150 r/min条件下对孔雀石绿的脱色率为97.14％, 通过革兰氏染色、电镜对其形态进行了观察, 用ATB细菌鉴定仪对其进行了生理生化鉴定; 通过对其16S rDNA序列进行PCR扩增和测序, 与NCBI中收录的与其同源性较高的菌株进行了聚类分析并构建了系统发育树。此外, 对其生长特性也进行了研究。实验结果表明, 菌株M6革兰氏染色阴性, 杆形, 端生一根鞭毛, 大小约为0.45 mm×0.84 mm, 在孔雀石绿营养琼脂平板上形成的菌落特征为圆形、浅蓝色、粘稠、不易挑取; 菌株M6的16S rDNA序列与GenBank基因库中假单胞菌属的细菌菌株的16S rDNA序列有98％~99％的高度同源性, 菌株M6与恶臭假单胞菌OW-16(登录号：DQ112328.1)的亲缘关系最近。结合传统的形态与生理生化特性鉴定以及16S rDNA序列分析鉴定的结果, 判定菌株M6为恶臭假单胞菌(Pseudomonas putida)(登录号：EU348741.1)。此外, 菌株M6在30°C、150 r/min条件下摇床振荡培养的生长曲线为：0 h~4 h为生长延迟期, 4 h~64 h为对数生长期, 64 h~80 h为稳定期, 80 h以后为衰亡期; 其最适生长pH值为7, 最适生长温度为30°C, 在转速为50 r/min~250 r/min条件下, 其浓度随转速的增加而增大。