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Limitation of adhesion and growth of Listeria monocytogenes on stainless steel surfaces by Staphylococcus sciuri biofilms

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JOURNAL OF APPLIED MICROBIOLOGY 2000年第4期88卷 594-605页

作者： Leriche, V Carpentier, B AFSSA Lerpac F-94709 Maisons Alfort France SODIAAL Union Paris France

The adhesion and subsequent development of Listeria monocytogenes on stainless steel was studied in the absence and in the presence of a Staphylococcus sciuri biofilm. In the three growth media studied, the percentage of adherent cells was reduced to nearly the same extent by the presence of 1-day biofilms of Staph. sciuri for the two strains of L. monocytogenes studied. One-day biofilms of Staph. sciuri exhibited the same exopolysaccharide content per square centimetre, although they colonized from 3.5 to 35% of the stainless steel depending on the growth media. This suggests that extracellular substances rather than cell-to-cell interactions were involved in the decreased adhesion. After 3 days of culture, Staphylococcus biofilms prevented the adherent L. monocytogenes population from increasing within the biofilm, leading to an average logarithmic cfu difference of 0.9-2.7 between the pure and mixed culture. A competition for nutrients by Staph. sciuri was observed in one of the three media. A role for extracellular polysaccharides produced by the Staphylococcus biofilm in preventing the adhesion of L. monocytogenes and in modifying the balance existing between its planktonic and biofilm phase is hypothesized. A higher proportion of L. monocytogenes cells was observed in the planktonic phase in mixed cultures, suggesting that the extracellular substances produced by Staph sciuri biofilms and involved in the decreased adhesion of L. monocytogenes could modify the balance existing between planktonic and biofilm populations. In addition, co-cultures of L. monocytogenes and Staph. sciuri in broth showed competition for nutrients for Staph. sciuri in one of the three media.

关键词：细菌黏附/生理学细菌蛋白质类/代谢生物膜/生长和发育共同培养技术单核细胞增生利斯特菌/生长和发育单核细胞增生利斯特菌/生理学聚合物多糖类细菌/代谢不锈钢葡萄球菌属/代谢

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The effect of culture growth phase on induction of the heat shock response in Yersinia enterocolitica and Listeria monocytogenes

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JOURNAL OF APPLIED MICROBIOLOGY 2000年第2期89卷 198-206页

作者： McMahon, CMM Byrne, CM Sheridan, JJ McDowell, DA Blair, IS Hegarty, T TEAGASC Natl Food Ctr Dublin 15 Ireland Univ Ulster Food Studies Res Unit Newtownabbey Co Antrim North Ireland TEAGASC Dept Stat Dublin 15 Ireland

The effect of culture growth phase on induction of the heat shock response in Yersinia enterocolitica and Listeria monocytogenes, was examined. Exponential or stationary preconditioned cultures were heat shocked and survivor numbers estimated using selective and overlay/resuscitation recovery techniques. The results indicate that prior heat shock induced increased heat resistance in both micro-organisms to higher heat treatments. Heat-shocked cells of each micro-organism were able to survive much longer than non-heat-shocked cells when heated at 55 degrees C. The size of the change in heat resistance between heat-shocked and non-heat-shocked cells was greatest for exponential cultures (X:X). Results indicate that the overall relative thermal resistance of each pathogen was dependent on cell growth phase. Stationary cultures (S:S) were significantly (P < 0.01) more thermotolerant than exponential cultures (X:X) under identical processing conditions. Under most conditions, the use of an overlay/resuscitation recovery medium resulted in higher D-values (P < 0.05) compared with a selective recovery medium.

关键词：集落计数微生物培养基热休克反应热温度单核细胞增生利斯特菌/生长和发育单核细胞增生利斯特菌/生理学小肠结肠炎耶尔森菌/生长和发育小肠结肠炎耶尔森菌/生理学

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A comparison of the Bioscreen method and microscopy for the determination of lag times of individual cells of Listeria monocytogenes

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LETTERS IN APPLIED MICROBIOLOGY 2000年第6期30卷 468-472页

作者： Wu, Y Griffiths, MW McKellar, RC Univ Guelph Dept Food Sci Guelph ON N1G 2W1 Canada Agr & Agri Food Canada Food Res Program Guelph ON Canada

Lag phase durations (t(Lag)) Of individual Listeria monocytogenes cells were analysed using the NightOwl Molecular Imaging System, and results were compared with mean individual cell lag times (t(L)) Obtained from the detection time (t(d)) method using Bioscreen. With Bioscreen, an average t(L) of 6 . 39 +/- 0 . 89 h was obtained from five separate experiments. With the NightOwl method, an average t(Lag) of 2 . 73 +/- 0 . 06 h was obtained from three experiments consisting of eight total replicates. Lag values from the NightOwl and Bioscreen are related by the equation: t(Lag) = t(L) + DT where DT is the doubling time. The equivalent t(Lag) mean value for the Bioscreen method was 7 . 11 +/- 0 . 84 h. Individual lag times measured by both methods were normally distributed (r(2) for Bioscreen and NightOwl ranged from 0 . 951 to 0 . 999 and from 0 . 884 to 0 . 982, respectively). The results suggest that the NightOwl method can provide accurate estimates of individual cell lag times, which will facilitate the development of combined discrete continuous models for bacterial growth.

关键词：生物传感技术细胞周期/生理学单核细胞增生利斯特菌/细胞学单核细胞增生利斯特菌/生长和发育单核细胞增生利斯特菌/生理学显微镜检查人类

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Physiological effects of high hydrostatic pressure treatments on Listeria monocytogenes and Salmonella typhimurium

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JOURNAL OF APPLIED MICROBIOLOGY 2000年第2期88卷 202-212页

作者： Tholozan, JL Ritz, M Jugiau, F Federighi, M Tissier, JP Inst Natl Rech Agron Lab Proc & Technol Alimentaire Villeneuve Dascq France Ecole Natl Vet Nantes Unite Associee INRA Hyg Alimentaire Nantes France

The effect of a high hydrostatic pressure treatment on the Gram-positive Listeria monocytogenes strain Scott A and the Gram-negative Salmonella typhimurium strain Mutton (ATCC13 311) has been determined in stationary phase cell suspensions. Pressure treatments were done at room temperature for 10 min in sodium citrate (pH 5.6) and sodium phosphate (pH 7.0) suspension buffers. Increasing pressure treatments resulted in an exponential decrease of cell counts. Salmonella typhimurium suspended at low pH was more sensitive to pressure treatments. Progressive morphological changes were evident with the pressure increase. Cell lysis only appeared with the highest pressure treatments. Cell volume was not affected by pressure treatment. A progressive decrease of delta pH (pH(in) - pH(out)), intracellular potassium and ATP contents was demonstrated with the pressure increase. A parallel lowering of membrane potentials was measured.

关键词：腺苷三磷酸/代谢集落计数微生物培养基氢离子浓度流体静力压单核细胞增生利斯特菌/代谢单核细胞增生利斯特菌/生理学单核细胞增生利斯特菌/超微结构膜电位显微镜检查电子扫描钾/代谢鼠伤寒沙门菌/代谢鼠伤寒沙门菌/生理学鼠伤寒沙门菌/超微结构

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Cellular morphology of rough forms of Listeria monocytogenes isolated from clinical and food samples

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LETTERS IN APPLIED MICROBIOLOGY 2000年第4期31卷 319-322页

作者： Rowan, NJ Anderson, JG Candlish, AAG Univ Strathclyde Dept Biosci & Biotechnol Glasgow G1 1XW Lanark Scotland

Transmission electron microscopy (TEM) studies revealed that rough cell-forms of L. monocytogenes (designated FR variants), isolated from clinical and food samples (and under conditions of sublethal heat stress), consist of either single or paired long-filaments. These FR variants markedly contrast in cell morphology from other previously described avirulent rough-mutants of L. monocytogenes that form long chains consisting of multiple cells of similar size (designated MCR variants). The identity of these Listeria isolates was determined using a commercially available, anti-Listeria polyclonal KPL antibody and by the API Listeria biochemical gallery. This study shows that filamentous rough-forms of L. monocytogenes may occur in clinical and food samples that are of undetermined pathogenicity.

关键词：酶联免疫吸附测定/方法食品微生物学单核细胞增生利斯特菌/细胞学单核细胞增生利斯特菌/分离和提纯单核细胞增生利斯特菌/致病力单核细胞增生利斯特菌/生理学李斯特菌病/微生物学显微镜检查电子人类

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Comparison of the attachment of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella typhimurium, and Pseudomonas fluorescens to lettuce leaves

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JOURNAL OF FOOD PROTECTION 2000年第10期63卷 1433-1437页

作者： Takeuchi, K Matute, CM Hassan, AN Frank, JF Univ Georgia Dept Food Sci & Technol Ctr Food Safety & Qual Enhancement Athens GA 30602 USA

Attachment of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Pseudomonas fluorescens on iceberg lettuce was evaluated by plate count and confocal scanning laser microscopy (CSLM). Attachment of each microorganism (similar to 10(8) CFU/ml) on the surface and the cut edge of lettuce leaves was determined. E. coli O157:H7 and L. monocytogenes attached preferentially to cut edges, while P. fluorescens attached preferentially to the intact surfaces. Differences in attachment at the two sites were greatest with L. monocytogenes. Salmonella Typhimurium attached equally to the two sites. At the surface, P. fluorescens attached in greatest number, followed by E. coli O157:H7, L. monocytogenes, and Salmonella Typhimurium. Attached microorganisms on lettuce were stained with fluorescein isothiocyanate and visualized by CSLM. Images at the surface and the cut edge of lettuce confirmed the plate count data. In addition, microcolony formation by P. fluorescens was observed on the lettuce surface. Some cells of each microorganism at the cut edge were located within the lettuce tissues, indicating that penetration occurred from the cut edge surface. The results of this study indicate that different species of microorganisms attach differently to lettuce structures, and CSLM can be successfully used to detect these differences.

关键词：细菌黏附/生理学细菌学技术集落计数微生物大肠杆菌O157/生理学莴苣/微生物学单核细胞增生利斯特菌/生理学显微镜检查共焦/方法荧光假单胞菌/生理学鼠伤寒沙门菌/生理学

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A role for α- and β-catenins in bacterial uptake

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PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2000年第18期97卷 10008-10013页

作者： Lecuit, M Hurme, R Pizarro-Cerdá, J Ohayon, H Geiger, B Cossart, P Inst Pasteur Unite Interact Bacteries Cellules F-75724 Paris 15 France Inst Pasteur Stn Cent Microscopie Elect F-75724 Paris France Weizmann Inst Sci Dept Mol Cell Biol IL-76100 Rehovot Israel

Interaction of internalin with E-cadherin promotes entry of Listeria monocytogenes into human epithelial cells. This process requires actin cytoskeleton rearrangements. Here we show, by using a series of stably transfected cell lines expressing E-cadherin variants, that the ectodomain of E-cadherin is sufficient for bacterial adherence and that the intracytoplasmic domain is required for entry. The critical cytoplasmic region was further mapped to the beta-catenin binding domain. Because beta-catenin is known to interact with alpha-catenin, which binds to actin, we generated a fusion molecule consisting of the ectodomain of E-cadherin and the actin binding site of alpha-catenin. Cells expressing this chimera were as permissive as E-cadherin-expressing cells. In agreement with these data, alpha- and beta-catenins as well as E-cadherin clustered and colocalized at the entry site, where F-actin then accumulated. Taken together, these results reveal that E-cadherin, via beta- and alpha-catenins, can trigger dynamic events of actin polymerization and membrane extensions culminating in bacterial uptake.

关键词：肌动蛋白类/代谢钙黏着糖蛋白类/生理学细胞系细胞支架蛋白质类/生理学利斯特菌属/生理学利斯特菌属/超微结构单核细胞增生利斯特菌/生理学重组融合蛋白质类/代谢序列缺失反式激活因子类转染肿瘤细胞培养的 α连环素 β连环素动物人类

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