scholarly journals Short-Term Pretreatment of Sub-Inhibitory Concentrations of Gentamycin Inhibits the Swarming Motility of Escherichia Coli by Down-Regulating the Succinate Dehydrogenase Gene

2016 ◽  
Vol 39 (4) ◽  
pp. 1307-1316 ◽  
Author(s):  
Yijing Zhuang ◽  
Weidong Chen ◽  
Fen Yao ◽  
Yuanchun Huang ◽  
Shuqin Zhou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Succinate Dehydrogenase ◽  
Infectious Agent ◽  
Short Term ◽  
Swarming Motility ◽  
Swimming Motility ◽  
E Coli ◽  
Solid Media ◽  
Antibiotic Effect ◽  
Semi Solid

Background/Aims: Motility is a feature of many pathogens that contributes to the migration and dispersion of the infectious agent. Whether gentamycin has a post-antibiotic effect (PAE) on the swarming and swimming motility of Escherichia coli (E. coli) remains unknown. In this study, we aimed to examine whether short-term pretreatment of sub-inhibitory concentrations of gentamycin alter motility of E. coli and the mechanisms involved therein. Methods: After exposure to sub-inhibitory concentrations (0.8 μg/ml) of gentamicin, the swarming and swimming motility of E. coli was tested in semi-solid media. Real-time PCR was used to detect the gene expression of succinate dehydrogenase (SDH). The production of SDH and fumarate by E. coli pretreated with or without gentamycin was measured. Fumarate was added to swarming agar to determine whether fumarate could restore the swarming motility of E. coli. Results: After pretreatment of E. coli with sub-inhibitory concentrations of gentamycin, swarming motility was repressed in the absence of growth inhibition. The expression of all four subunits of SDH was down-regulated, and the intracellular concentration of SDH and fumarate, produced by E. coli, were both decreased. Supplementary fumarate could restore the swarming motility inhibited by gentamycin. A selective inhibitor of SDH (propanedioic acid) could strongly repress the swarming motility. Conclusion: Sub-inhibitory concentrations of gentamycin inhibits the swarming motility of E. coli. This effect is mediated by a reduction in cellular fumarate caused by down-regulation of SDH. Gentamycin may be advantageous for treatment of E. coli infections.

Relationship of growth conditions to desiccation tolerance of Salmonella enterica, Escherichia coli, and Listeria monocytogenes

2021 ◽  
Author(s):  
Rachel K Streufert ◽  
Susanne E Keller ◽  
Joelle K Salazar
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Desiccation Tolerance ◽  
Salmonella Enterica ◽  
Growth Conditions ◽  
Initial Population ◽  
Desiccation Resistance ◽  
E Coli ◽  
Solid Media ◽  
Agar Media

Growth on solid media as sessile cells is believed to increase the desiccation tolerance of Salmonella enterica . However, the reasons behind increased resistance have not been well explored. In addition, the same effect has not been examined for other foodborne pathogens such as pathogenic Escherichia coli or Listeria monocytogenes . The purpose of this research was two-fold: first, to determine the role of oxygenation during growth on the desiccation resistance of S. enterica , E. coli , and L. monocytogenes , and second, to determine the effect of sessile versus planktonic growth on the desiccation resistance of these pathogens. Three different serotypes each of Salmonella , E. coli , and L. monocytogenes were cultured in trypticase soy broth with 0.6% yeast extract (TSBYE), with (aerobic) shaking or on TSBYE with agar (TSAYE) under either aerobic or anaerobic conditions and harvested in stationary phase. After adding cell suspensions to cellulose filter disks, pathogen survival was determined by enumeration at 0 and after drying for 24 h. Results showed statistical differences in harvested initial populations prior to drying (0 h). For Salmonella , a correlation was found between high initial population and greater survival on desiccation (p = 0.05). In addition, statistical differences (p ≤ 0.05) between survival based on growth type were identified. However, differences found were not the same for the three pathogens, or between their serotypes. In general, Salmonella and E. coli desiccation resistance followed the pattern of aerobic agar media ≥ liquid media ≥ anaerobic agar media. For L. monocytogenes serotypes, resistance to desiccation was not statistically different based on mode of growth. These results indicate growth on solid media under aerobic conditions is not always necessary for optimal desiccation survival but may be beneficial when the desiccation resistance of the test serotype is unknown.

Evaluation of Structurally Different Carotenoids inEscherichia coli Transformants as Protectants against UV-B Radiation

1998 ◽  
Vol 64 (5) ◽  
pp. 1972-1974 ◽  
Author(s):  
Gerhard Sandmann ◽  
Silvia Kuhn ◽  
Peter B�ger
Keyword(s):  
Escherichia Coli ◽  
Inescherichia Coli ◽  
Short Term ◽  
E Coli ◽  
Carotenogenic Genes ◽  
Β Carotene

ABSTRACT Escherichia coli cells transformed with several carotenogenic genes to mediate the formation of ζ-carotene, neurosporene, lycopene, β-carotene, and zeaxanthin were exposed to UV-B radiation. Short-term kinetics revealed that endogenous levels of neurosporene and β-carotene protected E. coli against irradiation with UV-B. Zeaxanthin protected against only the photosensitized UV-B treatment. All other carotenoids were ineffective.

scholarly journals Transcriptional Responses of Escherichia coli K-12 and O157:H7 Associated with Lettuce Leaves

2012 ◽  
Vol 78 (6) ◽  
pp. 1752-1764 ◽  
Author(s):  
Ryan C. Fink ◽  
Elaine P. Black ◽  
Zhe Hou ◽  
Masayuki Sugawara ◽  
Michael J. Sadowsky ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Leaf Surface ◽  
Short Term ◽  
Transcriptional Responses ◽  
Content Type ◽  
E Coli ◽  
Leaf Surfaces ◽  
K 12

ABSTRACTAn increasing number of outbreaks of gastroenteritis recently caused byEscherichia coliO157:H7 have been linked to the consumption of leafy green vegetables. Although it is known thatE. colisurvives and grows in the phyllosphere of lettuce plants, the molecular mechanisms by which this bacterium associates with plants are largely unknown. The goal of this study was to identifyE. coligenes relevant to its interaction, survival, or attachment to lettuce leaf surfaces, comparingE. coliK-12, a model system, andE. coliO157:H7, a pathogen associated with a large number of outbreaks. Using microarrays, we found that upon interaction with intact leaves, 10.1% and 8.7% of the 3,798 shared genes were differentially expressed in K-12 and O157:H7, respectively, whereas 3.1% changed transcript levels in both. The largest group of genes downregulated consisted of those involved in energy metabolism, includingtnaA(33-fold change), encoding a tryptophanase that converts tryptophan into indole. Genes involved in biofilm modulation (bhsAandybiM) and curli production (csgAandcsgB) were significantly upregulated inE. coliK-12 and O157:H7. BothcsgAandbhsA(ycfR) mutants were impaired in the long-term colonization of the leaf surface, but onlycsgAmutants had diminished ability in short-term attachment experiments. Our data suggested that the interaction ofE. coliK-12 and O157:H7 with undamaged lettuce leaves likely is initiated via attachment to the leaf surface using curli fibers, a downward shift in their metabolism, and the suppression of biofilm formation.

scholarly journals Neutralizationof Enteric Coronaviruses with Escherichia coli CellsExpressing Single-Chain Fv-AutotransporterFusions

2003 ◽  
Vol 77 (24) ◽  
pp. 13396-13398 ◽  
Author(s):  
Esteban Veiga ◽  
Víctor de Lorenzo ◽  
Luis Angel Fernández
Keyword(s):  
Escherichia Coli ◽  
Infectious Agent ◽  
Target Cells ◽  
Single Chain ◽  
E Coli ◽  
Single Chain Antibodies ◽  
Single Chain Fv ◽  
Transmissible Gastroenteritis ◽  
Iga Protease

ABSTRACT We report here that fusions of single-chain antibodies (scFvs) to the autotransporter β domain of the IgA protease of Neisseria gonorrhoeae are instrumental in locating virus-neutralizing activity on the cell surface of Escherichia coli. E. coli cells displaying scFvs against the transmissible gastroenteritis coronavirus on their surface blocked in vivo the access of the infectious agent to cultured epithelial cells. This result raises prospects for antiviral strategies aimed at hindering the entry into target cells by bacteria that naturally colonize the same intestinal niches.

scholarly journals RNase E Maintenance of Proper FtsZ/FtsA Ratio Required for Nonfilamentous Growth of Escherichia coli Cells but Not for Colony-Forming Ability

2006 ◽  
Vol 188 (14) ◽  
pp. 5145-5152 ◽  
Author(s):  
Masaru Tamura ◽  
Kangseok Lee ◽  
Christine A. Miller ◽  
Christopher J. Moore ◽  
Yukio Shirako ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Liquid Culture ◽  
Bacterial Cells ◽  
Rnase E ◽  
Null Mutant ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Solid Media ◽  
Rnase G

ABSTRACT Inactivation or deletion of the RNase E-encoding rne gene of Escherichia coli results in the growth of bacterial cells as filamentous chains in liquid culture (K. Goldblum and D. Apirion, J. Bacteriol. 146:128-132, 1981) and the loss of colony-forming ability (CFA) on solid media. RNase E dysfunction is also associated with abnormal processing of ftsQAZ transcripts (K. Cam, G. Rome, H. M. Krisch, and J.-P. Bouché, Nucleic Acids Res. 24:3065-3070, 1996), which encode proteins having a central role in septum formation during cell division. We show here that RNase E regulates the relative abundances of FtsZ and FtsA proteins and that RNase E depletion results in decreased FtsZ, increased FtsA, and consequently an altered FtsZ/FtsA ratio. However, while restoration of the level of FtsZ to normal in rne null mutant bacteria reverses the filamentation phenotype, it does not restore CFA. Conversely, overexpression of a related RNase, RNase G, in rne-deleted bacteria restores CFA, as previously reported, without affecting FtsZ abundance. Our results demonstrate that RNase E activity is required to maintain a proper cellular ratio of the FtsZ and FtsA proteins in E. coli but that FtsZ deficiency does not account for the nonviability of cells lacking RNase E.

scholarly journals Trans-Kingdom Conjugation Within Solid Media from Escherichia coli to Saccharomyces cerevisiae

2019 ◽  
Author(s):  
Maximillian P.M. Soltysiak ◽  
Rebecca S. Meaney ◽  
Samir Hamadache ◽  
Preetam Janakirama ◽  
David R. Edgell ◽  
...  
Keyword(s):  
Donor Cell ◽  
Dna Delivery ◽  
Dna Transfer ◽  
Liquid Media ◽  
E Coli ◽  
Solid Media ◽  
Wide Range ◽  
Semi Solid ◽  
Plasmid Size ◽  
Synthesis Protocol

Conjugation is a bacterial mechanism for DNA transfer from a donor cell to a wide range of recipients, including both prokaryotic and eukaryotic cells. In contrast to conventional DNA delivery techniques, such as electroporation and chemical transformation, conjugation eliminates the need for DNA extraction, thereby preventing DNA damage during isolation. While most established conjugation protocols allow for DNA transfer in liquid media or on a solid surface, we developed a procedure for conjugation within solid media. Such a protocol may expand conjugation as a tool for DNA transfer to species that require semi-solid or solid media for growth. Conjugation within solid media could also provide a more stable microenvironment in which the conjugative pilus can establish and maintain contact with recipient cells for the successful delivery of plasmid DNA. Furthermore, transfer in solid media may enhance the ability to transfer plasmids and chromosomes greater than 100 kbp. Using our optimized method, plasmids of varying sizes were tested for transfer from E. coli to S. cerevisiae. We demonstrated that there was no substantial decrease in conjugation frequency as plasmid size increased—up to 138.5 kbp in length. Finally, we established an efficient PCR-based synthesis protocol to generate custom conjugative plasmids

scholarly journals Trans-Kingdom Conjugation within Solid Media from Escherichia coli to Saccharomyces cerevisiae

2019 ◽  
Vol 20 (20) ◽  
pp. 5212 ◽  
Author(s):  
Maximillian P. M. Soltysiak ◽  
Rebecca S. Meaney ◽  
Samir Hamadache ◽  
Preetam Janakirama ◽  
David R. Edgell ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Donor Cell ◽  
Dna Delivery ◽  
Dna Transfer ◽  
Solid Media ◽  
Wide Range ◽  
Semi Solid ◽  
Plasmid Size ◽  
Synthesis Protocol

Conjugation is a bacterial mechanism for DNA transfer from a donor cell to a wide range of recipients, including both prokaryotic and eukaryotic cells. In contrast to conventional DNA delivery techniques, such as electroporation and chemical transformation, conjugation eliminates the need for DNA extraction, thereby preventing DNA damage during isolation. While most established conjugation protocols allow for DNA transfer in liquid media or on a solid surface, we developed a procedure for conjugation within solid media. Such a protocol may expand conjugation as a tool for DNA transfer to species that require semi-solid or solid media for growth. Conjugation within solid media could also provide a more stable microenvironment in which the conjugative pilus can establish and maintain contact with recipient cells for the successful delivery of plasmid DNA. Furthermore, transfer in solid media may enhance the ability to transfer plasmids and chromosomes greater than 100 kbp. Using our optimized method, plasmids of varying sizes were tested for transfer from Escherichia coli to Saccharomyces cerevisiae. We demonstrated that there was no significant change in conjugation frequency when plasmid size increased from 56.5 to 138.6 kbp in length. Finally, we established an efficient PCR-based synthesis protocol to generate custom conjugative plasmids.

scholarly journals Tumble Suppression Is a Conserved Feature of Swarming Motility

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Jonathan D. Partridge ◽  
Nguyen T. Q. Nhu ◽  
Yann S. Dufour ◽  
Rasika M. Harshey
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Behavioral Adaptation ◽  
Diverse Group ◽  
Swarming Motility ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Surfactant Secretion ◽  
Motility Parameters

ABSTRACT Many bacteria use flagellum-driven motility to swarm or move collectively over a surface terrain. Bacterial adaptations for swarming can include cell elongation, hyperflagellation, recruitment of special stator proteins, and surfactant secretion, among others. We recently demonstrated another swarming adaptation in Escherichia coli, wherein the chemotaxis pathway is remodeled to decrease tumble bias (increase run durations), with running speeds increased as well. We show here that the modification of motility parameters during swarming is not unique to E. coli but is shared by a diverse group of bacteria we examined—Proteus mirabilis, Serratia marcescens, Salmonella enterica, Bacillus subtilis, and Pseudomonas aeruginosa—suggesting that increasing run durations and speeds are a cornerstone of swarming. IMPORTANCE Bacteria within a swarm move characteristically in packs, displaying an intricate swirling motion in which hundreds of dynamic rafts continuously form and dissociate as the swarm colonizes an increasing expanse of territory. The demonstrated property of E. coli to reduce its tumble bias and hence increase its run duration during swarming is expected to maintain and promote side-by-side alignment and cohesion within the bacterial packs. In this study, we observed a similar low tumble bias in five different bacterial species, both Gram positive and Gram negative, each inhabiting a unique habitat and posing unique problems to our health. The unanimous display of an altered run-tumble bias in swarms of all species examined in this investigation suggests that this behavioral adaptation is crucial for swarming.

scholarly journals The biotyping ofEscherichia coliisolated from healthy farm animals

1982 ◽  
Vol 88 (3) ◽  
pp. 543-555 ◽  
Author(s):  
M. Hinton ◽  
Vivien Allen ◽  
A. H. Linton
Keyword(s):  
Escherichia Coli ◽  
Farm Animals ◽  
Drug Resistant ◽  
E Coli ◽  
Solid Media ◽  
Resistant Strains ◽  
Drug Resistant Strains

SummaryA total of 2973Escherichia coli, isolated from six different groups of animals, were examined for their ability to ferment adonitol, dulcitol, raffinose, rhamnose and sorbose in solid media. Twenty-nine fermentation patterns were recorded although 2443 (82%) of theE. colibelonged to seven of the 32 possible biotypes. Ninety-six O-serotypes were identified within the 2973E. coli.The number of O-serotypes represented in the 15 most common biotypes ranged from three to 15. Sero types O8 and O9 were found most commonly in the different groups of animals and several biotypes amongst these two O-serotypes were identified in two or more groups of the animals. The ability of theE. colito metabolize aesculin, ornithine, salicin and sucrose was also assessed. These tests proved less reproducible and were not included in the primary biotyping scheme although their use allowed the enumeration of additional biotypes. The application of biotyping to the study of the ecology of drug-resistant strains ofE. coliin five situations is briefly presented.

scholarly journals Escherichia coli robustly expresses ATP synthase at growth rate maximizing concentrations

2021 ◽  
Author(s):  
Iraes Rabbers ◽  
Frank J Bruggeman
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Protein Expression ◽  
Genetic Variants ◽  
Evolutionary Adaptation ◽  
Wild Type ◽  
Short Term ◽  
E Coli ◽  
Fitness Maximization

AbstractImproved protein expression is an important evolutionary adaptation of bacteria. A key question is whether evolution has led to optimal protein expression that maximizes immediate growth rate (short-term fitness) across conditions. Alternatively, fitter genetic variants could display suboptimal short-term fitness, because they cannot do better or because they strive for long-term fitness maximization by, for instance, anticipating future conditions. To answer this question, we focus on the ATP-producing enzyme F1F0 H+-ATPase, which is an abundant enzyme and ubiquitously expressed across conditions. We tested the optimality of H+-ATPase expression in Escherichia coli across 27 different nutrient conditions. In all tested conditions, wild-type E. coli expresses its H+- ATPase remarkably close to optimal concentrations that maximize immediate growth rate. This work indicates that bacteria can achieve robust optimal protein expression for immediate growth- rate.

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