Microbial releases : viruses, bacteria, fungi最新文献

Isolation of a Rhizobium galegae strain-specific DNA probe. 一种galegae根瘤菌DNA探针的分离。

Microbial releases : viruses, bacteria, fungi Pub Date : 1994-07-01

E Tas, S Kaijalainen, A Saano, K Lindström

引用次数: 0

Survival and respiratory activity of genetically engineered Pseudomonas spp. exposed to antimicrobial agents in broth and soil. 暴露于肉汤和土壤中抗菌剂的基因工程假单胞菌的存活和呼吸活性。

Microbial releases : viruses, bacteria, fungi Pub Date : 1994-07-01

S C Weir, H Lee, J T Trevors

{"title":"Survival and respiratory activity of genetically engineered Pseudomonas spp. exposed to antimicrobial agents in broth and soil.","authors":"S C Weir, H Lee, J T Trevors","doi":"","DOIUrl":"","url":null,"abstract":"The effectiveness of seven chemical disinfectants were tested against genetically engineered Pseudomonas spp. under optimal growth conditions. Each chemical was tested to determine how quickly 10(8) cells/ml Pseudomonas fluorescens C5t (containing Bacillus thuringiensis endotoxin gene) were killed in King's B broth at 30 degrees C. The minimal bactericidal concentrations (MBC) for calcium hypochlorite, benzalkonium chloride, Germiphene and Spectrum Clear Bath were 0.06% (w/v), 0.01% (w/v), 0.08% (v/v) and 0.044 (v/v), respectively. Virocidin X and CanLab Neutral did not kill P. fluorescens C5t at concentrations up to 20% (v/v). Baxter Bacdown was ineffective as a killing agent at concentrations up to 10% (v/v). These agents were also tested on P. aureofaciens RNL11 (lacZY), P. putida strains PaW8 and PaW340 (containing the plasmid pLV1013 encoding the xylE gene) and P. aeruginosa UG2L (lacZY and luxAB). All strains were killed by similar disinfectant concentrations with the exception of P. aeruginosa UG2L. The MBCs for this strain were double the MBCs for P. fluorescens C5t with all disinfectants used except for Spectrum Clear Bath, which was similar. Oxygen consumption and carbon dioxide evolution were used to assess the activity of P. fluorescens C5t inoculated in non-sterile soil in the presence of antimicrobial agents. Concentrations chosen were 0.1 and 1.0% (w/v) calcium hypochlorite, 0.01 and 0.1% (w/v) benzalkonium chloride, 0.1 and 1.0% (v/v) Germiphene and 0.1 and 1.0% (v/v) Spectrum Clear Bath. Over a 15-day period, the antimicrobial agents did not reduce respiratory activity of P. fluorescens C5t and indigenous soil micro-organisms.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":77262,"journal":{"name":"Microbial releases : viruses, bacteria, fungi","volume":"2 4","pages":"239-45"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18917174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of gene transfer in vitro and in the digestive tract of gnotobiotic mice from Lactococcus lactis strains to various strains belonging to human intestinal flora. 乳酸乳球菌基因在体外和无菌小鼠消化道内向人类肠道菌群中不同菌株转移的研究。

Microbial releases : viruses, bacteria, fungi Pub Date : 1994-07-01

M Gruzza, M Fons, M F Ouriet, Y Duval-Iflah, R Ducluzeau

{"title":"Study of gene transfer in vitro and in the digestive tract of gnotobiotic mice from Lactococcus lactis strains to various strains belonging to human intestinal flora.","authors":"M Gruzza, M Fons, M F Ouriet, Y Duval-Iflah, R Ducluzeau","doi":"","DOIUrl":"","url":null,"abstract":"The use of genetically modified organisms (GMO) in dairy products requires evaluation of the DNA transfer capacity from such organisms among the human intestinal microflora. Thus, both in vitro and in vivo [in the digestive tract (DT) of mice] transfer from Lactococcus lactis donor strains of the conjugative plasmid pIL205 (CmR) and the non-conjugative plasmid pIL253 (EmR) to: (1) recipient strains isolated from human faecal flora Bacteroides sp., Bifidobacterium sp., Peptostreptococcus sp. (strictly anaerobic bacterial strains) and Enterococcus faecalis, (2) a whole human faecal flora, was studied. In both cases, no gene transfer was observed to strictly anaerobic bacterial strains. DNA transfer was only observed to the E. faecalis strain: in vivo CmR E. faecalis transconjugants were isolated from sequentially multi-associated mice and when the recipient strains associated with the mice, they were a defined mixture of Bacteroides sp., Bifidobacterium sp., Peptostreptococcus sp. and E. faecalis strains. When mice were associated with the whole human faecal flora, the plasmid pIL205 was transferred into some facultative anaerobic streptococci. It was also shown that DNA transfer occurred even when the lactococcal donor strain was transient in the DT of the gnotobiotic host animals.","PeriodicalId":77262,"journal":{"name":"Microbial releases : viruses, bacteria, fungi","volume":"2 4","pages":"183-9"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18917171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pseudomonas aureofaciens in soil: survival and recovery efficiency. 金黄色假单胞菌在土壤中的生存和恢复效率。

Microbial releases : viruses, bacteria, fungi Pub Date : 1994-07-01

J S Angle, M A Levin, J V Gagliardi, M S McIntosh, J G Glew

{"title":"Pseudomonas aureofaciens in soil: survival and recovery efficiency.","authors":"J S Angle, M A Levin, J V Gagliardi, M S McIntosh, J G Glew","doi":"","DOIUrl":"","url":null,"abstract":"Efficient methods for the recovery of genetically engineered organisms (GEM) added to soil are critical if the safety of potential releases is to be evaluated and the actual release is to be monitored. Pseudomonas aureofaciens strain 3732 RN-L11 (lacZY) was added to 10 g sieved soil microcosms and incubated for 5 and 28 days. Various diluents, shaking methods, and settling of soil were examined to determine the optimum method for recovery of the GEM from the soil. Of the diluents examined, 0.1% agar gave significantly lower numbers than distilled water, 1.0% sodium metaphosphate, 1% peptone, and phosphate-buffered water. After 5 days of incubation, shaking for 10 min with glass beads and shaking for 30 min without glass beads resulted in the highest recovery of the GEM from soil, while sonification resulted in the lowest recovery. After 28 days of incubation, sonification produced significantly lower numbers than any of the other treatments. The addition of 1% CaCl2 to enhance settling significantly increased recovery efficiency. Although the use of CaCl2 in distilled water and shaking for 10 min was an effective method for recovering P. aureofaciens from a Maryland soil, when the same extraction procedure was compared with a standard technique (dd H2O, shaking for 10 min) for eight divergent soils, neither extraction method was consistently better than the other. Statistical analysis of the data showed the need for log transformation of the raw data. Four microcosm and two plate replicates for each dilution provided the greatest ability to detect differences between treatment means while maximizing experimental efficiency.","PeriodicalId":77262,"journal":{"name":"Microbial releases : viruses, bacteria, fungi","volume":"2 4","pages":"247-54"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18917176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Metabolic deprivation: a lead to containment in bacterial releases. 代谢剥夺:导致控制细菌释放。

Microbial releases : viruses, bacteria, fungi Pub Date : 1994-07-01

W Klingmüller

{"title":"Metabolic deprivation: a lead to containment in bacterial releases.","authors":"W Klingmüller","doi":"","DOIUrl":"","url":null,"abstract":"Experiments were carried out in non-sterile soil, with or without several substrates (sucrose, citrate, lactose) as energy source, and with or without bacterial inoculates able or unable to utilize these substrates. The bacteria were Enterobacter agglomerans, Escherichia coli, Pseudomonas aeruginosa or Pseudomonas aureofaciens; they either did or did not contain plasmid RP4. It was found that sucrose is degraded by the indigenous microflora and/or free soil enzymes to give extracellular glucose and fructose, to support growth and plasmid transfer of all inoculated bacteria, e.g. sucrose-positive and sucrose-negative bacteria. In contrast, the growth and plasmid transfer of inoculates which do not degrade citrate is reduced in soil containing that substrate when compared to such inoculates which do degrade citrate. The growth and plasmid transfer of inoculates which do not degrade lactose is reduced strongly in soil containing that substrate, when compared to such inoculates which do degrade lactose. Lactose is degraded slowly in soil by the indigenous microflora, without giving rise to extracellular glucose. These findings indicate a possible way to achieve biological containment, via genetic defects in metabolic pathways.","PeriodicalId":77262,"journal":{"name":"Microbial releases : viruses, bacteria, fungi","volume":"2 4","pages":"289-92"},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18917011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gene transfer from engineered Lactococcus lactis strains to Enterococcus faecalis in the digestive tract of gnotobiotic mice. 转基因乳酸乳球菌向粪肠球菌的基因转移。

Microbial releases : viruses, bacteria, fungi Pub Date : 1993-12-01

M Gruzza, P Langella, Y Duval-Iflah, R Ducluzeau

引用次数: 0

Mineralization of p-methyl-14C-benzoate in soils by Pseudomonas putida (pWW0). 腐殖假单胞菌(pWW0)对土壤中对甲基- 14c -苯甲酸盐的矿化作用

Microbial releases : viruses, bacteria, fungi Pub Date : 1993-12-01

E Duque, S Marqués, J L Ramos

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Effects of pili rigidity and energy availability on conjugative plasmid transfer in aquatic environments. 毛刚性和能量有效性对水生环境中共轭质粒转移的影响。

Microbial releases : viruses, bacteria, fungi Pub Date : 1993-12-01

P Lebaron, V Roux, M C Lett, B Baleux

引用次数: 0

Transfer of plasmid RP4 from Escherichia coli K-12 to indigenous bacteria of seawater. 大肠杆菌K-12质粒RP4向海水原生细菌的转移。

Microbial releases : viruses, bacteria, fungi Pub Date : 1993-12-01

S J Sørensen

{"title":"Transfer of plasmid RP4 from Escherichia coli K-12 to indigenous bacteria of seawater.","authors":"S J Sørensen","doi":"","DOIUrl":"","url":null,"abstract":"Transfer of plasmid RP4 from Escherichia coli K-12 donor strain to bacteria isolated from seawater was shown to occur on filters and in sterile seawater incubated at 24 degrees C. Ten of 12 seawater isolates tested were recipient active for RP4 when the plasmid transfers were assessed by filter matings. When matings were performed in sterile seawater, seven of the 12 isolates received RP4. In sterile seawater, the transfer of RP4 from E. coli to pseudomonads was more efficient than transfer between E. coli strains. Transfer of RP4 to indigenous seawater bacteria was shown to take place both on filters and in seawater amended with Luria Bertani broth. No transconjugants were found in experiments with unamended seawater, but in experiments with amended seawater 10(-7)-10(-6) transconjugants per recipient were found. In filter matings with a 100-fold-concentrated total population of indigenous seawater bacteria, the transfer efficiency of RP4 was 4 x 10(-5) per recipient. The majority of the isolated transconjugant seawater bacteria consisted of fluorescent pseudomonads, but transconjugant strains of Aeromonas hydrophila, Pseudomonas cepacia, and Enterobacter cloacae were also found. Using an auxotrophic donor strain, selection of transconjugants on selective minimal media was shown to be an efficient strategy for detection of gene transfer to indigenous bacteria of seawater.","PeriodicalId":77262,"journal":{"name":"Microbial releases : viruses, bacteria, fungi","volume":"2 3","pages":"135-41"},"PeriodicalIF":0.0,"publicationDate":"1993-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19103850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of temperature on survival of Legionella pneumophila in the aquatic environment. 温度对嗜肺军团菌在水生环境中存活的影响。

Microbial releases : viruses, bacteria, fungi Pub Date : 1993-09-01

C Paszko-Kolva, M Shahamat, R R Colwell

{"title":"Effect of temperature on survival of Legionella pneumophila in the aquatic environment.","authors":"C Paszko-Kolva, M Shahamat, R R Colwell","doi":"","DOIUrl":"","url":null,"abstract":"Although Legionella spp. are often isolated from natural aquatic habitats, outbreaks of legionellosis are rarely traced to these sources. To determine the fate of Legionella pneumophila in the environment, filtered and unfiltered river water and seawater microcosms, incubated at 4 degrees C and 26 degrees C, were inoculated with [3H]thymidine-labeled L. pneumophila cells. Survival in these microcosms was monitored using [3H]thymidine labeling and culture on buffered-charcoal yeast extract agar amended with alpha-ketoglutarate (BCYE alpha). Immunofluorescent microscopy, direct fluorescent antibody staining, and acridine orange direct counts were also employed. To assess effects of grazing on Legionella, a duplicate set of samples was filtered through 2.0-microns Nuclepore filters to trap large protozoa. Over the test period, in the microcosms incubated at 4 degrees C, the culturable counts decreased ca. 1 log on BCYE alpha agar, with no substantial decline in thymidine count. Autoclaved seawater and river water controls held at 15 degrees C also showed no change in thymidine count. At 26 degrees C, a 3-log decline was observed in culturable counts, with ca. 1-log decline in thymidine counts. These results indicate that, although culturability declined by one to three orders of magnitude, when L. pneumophila microcosms were incubated at 4 degrees C and 26 degrees C, the cells remained metabolically active for extended periods, especially at 4 degrees C.","PeriodicalId":77262,"journal":{"name":"Microbial releases : viruses, bacteria, fungi","volume":"2 2","pages":"73-9"},"PeriodicalIF":0.0,"publicationDate":"1993-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19248649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0