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swarming motility

Anne E Mattingly, Nachiket Kamatkar, Bradley R Borlee, Joshua D Shrout
Pseudomonas aeruginosa exhibits flagellar-mediated swimming in liquid and swarming on hydrated surfaces under diverse nutrient conditions. Prior studies have implicated a phosphodiesterase, DipA, in regulating these flagella-mediated motilities, but collectively, the necessity for DipA was unclear. In this study, we find that the media composition conditionally constrains the influence of DipA on flagellar motility. We show that DipA exhibits more influence on minimal media supplemented with glutamate or glucose where flagellar motility was negated for the dipA mutant...
February 2, 2018: Applied and Environmental Microbiology
Chelsie E Armbruster, Harry L T Mobley, Melanie M Pearson
Proteus mirabilis , a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTIs) that are often polymicrobial. These infections may be accompanied by urolithiasis, the development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae...
February 2018: EcoSal Plus
Tingting Li, Dangfeng Wang, Nan Liu, Yan Ma, Ting Ding, Yongchao Mei, Jianrong Li
Pseudomonas fluorescens, an important food spoiling bacteria, uses quorum sensing to control biofilm formation and motility. To date, only a few compounds targeting the LuxR-based quorum sensing system of P. fluorescens have been identified. In the present study, the quorum sensing inhibitory effect of cinnamaldehyde at sublethal concentrations was investigated in terms of inhibition of the extracellular protease, biofilm formation, and swimming and swarming motility. The total volatile basic nitrogen value was also measured to evaluate the effect of cinnamaldehyde on quality preservation of turbot fillets stored at 4 ± 1 °C for 15 days...
February 1, 2018: International Journal of Food Microbiology
Felix LewisOscar, Chari Nithya, Sulaiman Ali Alharbi, Naiyf S Alharbi, Nooruddin Thajuddin
Biofilm forming pathogenic bacteria showing resistance towards antimicrobial agents has increased the urge to find an alternative treatment strategy. Among the biofilm forming pathogenic bacteria, Pseudomonas aeruginosa is a well-recognised Gram negative biofilm former causing nosocomial infection and other disease among immunocompromised patients. The aim of the current study is to evaluate the antipathogenic potentials of S. platensis against P. aeruginosa. S. platensis methanolic extract (SME) inhibited the biofilm (89%), extracellular polymeric substances (EPS), cell surface hydrophobicity (CSH) (44%), pyocyanin, pyoveridin and swarming motility of P...
January 31, 2018: Microbial Pathogenesis
Jakia Jannat Keya, Ryuhei Suzuki, Arif Md Rashedul Kabir, Daisuke Inoue, Hiroyuki Asanuma, Kazuki Sada, Henry Hess, Akinori Kuzuya, Akira Kakugo
In nature, swarming behavior has evolved repeatedly among motile organisms because it confers a variety of beneficial emergent properties. These include improved information gathering, protection from predators, and resource utilization. Some organisms, e.g., locusts, switch between solitary and swarm behavior in response to external stimuli. Aspects of swarming behavior have been demonstrated for motile supramolecular systems composed of biomolecular motors and cytoskeletal filaments, where cross-linkers induce large scale organization...
January 31, 2018: Nature Communications
Yimin Hu, Quanxin Cai, Shen Tian, Yong Ge, Zhiming Yuan, Xiaomin Hu
DegS and DegU make up a two component system belonging to a class of signal transduction systems that play important roles in a broad range of bacterial responses to the environment. However, little study has been done to explore the physiological functions of DegS-DegU in mosquitocidal Lysinibacillus sphaericus. In this study, it was found that deletion of degU or degS-degU inhibited the swarming motility, biofilm formation, sporulation and binary toxin production through regulating the related genes, and phosphorylation was necessary for the functions of DegU...
January 25, 2018: Research in Microbiology
Cibelle B Dallagassa, Monica Surek, Bruno S Vizzotto, Karoline C Prediger, Bárbara Moriel, Suélen Wolf, Vinícius Weiss, Leonardo M Cruz, Flávia E A Assis, Katia S Paludo, Fabiane G M Rego, Sônia M S S Farah, Geraldo Picheth, Emanuel M Souza, Fábio O Pedrosa, Leda S Chubatsu, Cyntia M T Fadel-Picheth
Aeromonas are ubiquitous in aquatic habitats. However some species can cause infections in humans, but rarely meningitis. Here we describe the isolation and characterization of an Aeromonas strain from cerebrospinal fluid of a meningitis patient. The isolate, identified as A. trota by biochemical and molecular methods, was susceptible to ampicillin but resistant to cephalothin and cefazolin. Genome sequencing revealed virulence factor genes such as type VI secretion system, aerolysin and lateral flagella. The isolate exhibited swarming motility, hemolytic activity and adhesion and cytotoxicity on HeLa cells...
January 16, 2018: Microbial Pathogenesis
Mingfa Lv, Yufan Chen, Lisheng Liao, Zhibin Liang, Zurong Shi, Yingxin Tang, Sixuan Ye, Jianuan Zhou, Lianhui Zhang
Dickeya zeae is the causal agent of rice foot rot disease, which has recently become a great threat to rice planting countries and regions. The pathogen produces a family of phytotoxins named zeamines that is critical for bacterial virulence, but little is known about the signaling pathways and regulatory mechanisms that govern zeamine production. In this study, we showed that a conserved transcriptional regulator Fis is involved in the regulation of zeamine production in D. zeae strain EC1. Deletion mutants were markedly attenuated in the virulence against rice seed germination...
January 10, 2018: Scientific Reports
Anna C Hughes, Sundharraman Subramanian, Charles E Dann, Daniel B Kearns
SwrA is the master activator of flagellar biosynthesis in Bacillus subtilis and SwrA activity is restricted by regulatory proteolysis in liquid environments. SwrA is proteolyzed by the LonA protease but requires a proteolytic adaptor protein, SmiA. Here we show that SwrA and SmiA interact directly. To better understand SwrA activity, SwrA was randomly mutagenized and loss-of-function and gain-of-function mutants were localized primarily to the predicted unstructured C-terminal region. Loss-of-function mutations impaired swarming motility and activation from the Pfla-che promoter...
January 8, 2018: Journal of Bacteriology
Nicholas A Stella, Kimberly M Brothers, Jake D Callaghan, Angelina M Passerini, Cihad Sigindere, Preston J Hill, Xinyu Liu, Daniel J Wozniak, Robert M Q Shanks
Secondary metabolites are an important source of pharmaceuticals and key modulators of microbe-microbe interactions. The bacterium Serratia marcescens is part of the Enterobacteriaceae family of eubacteria and produces a number of biologically active secondary metabolites. In this study, we screened for novel regulators of secondary metabolites synthesized by a clinical isolate of S. marcescens and found mutations in a gene for an uncharacterized UmoB/IgaA family member here named gumB Mutation of gumB conferred a severe loss of secondary metabolites prodigiosin and serratamolide...
January 5, 2018: Applied and Environmental Microbiology
Ramanathan Srinivasan, Ramar Mohankumar, Arunachalam Kannappan, Veeramani Karthick Raja, Govindaraju Archunan, Shunmugiah Karutha Pandian, Kandasamy Ruckmani, Arumugam Veera Ravi
Quorum Sensing (QS) mechanism, a bacterial density-dependent gene expression system, governs the Serratia marcescens pathogenesis through the production of virulence factors and biofilm formation. The present study demonstrates the anti-quorum sensing (anti-QS), antibiofilm potential and in vivo protective effect of phytol, a diterpene alcohol broadly utilized as food additive and in therapeutics fields. In vitro treatment of phytol (5 and 10 μg/ml) showed decreasing level of biofilm formation, lipase and hemolysin production in S...
2017: Frontiers in Cellular and Infection Microbiology
Jing Shi, Yiwei Liu, Yueying Zhang, Yongxin Jin, Fang Bai, Zhihui Cheng, Shouguang Jin, Weihui Wu
Pseudomonas aeruginosa causes various acute and chronic infections in human. Treatment with azithromycin (AZM) has been shown to benefit patients with chronic P. aeruginosa infections. By binding to the exit tunnel of 50S ribosome, AZM causes ribosome stalling and depletion of intracellular tRNA pool. It has been shown that AZM is able to kill stationary-phase P. aeruginosa cells and repress quorum sensing regulated virulence factors as well as swarming motility. In P. aeruginosa, PA5470 encodes a putative peptide chain release factor, whose expression is highly induced by macrolide antibiotics...
December 4, 2017: Antimicrobial Agents and Chemotherapy
Felix LewisOscar, Chari Nithya, Sulaiman Ali Alharbi, Naiyf S Alharbi, Nooruddin Thajuddin
Pseudomonas aeruginosa is a Gram negative, opportunistic biofilm forming pathogenic bacterium which is developing as a serious problem worldwide. The pathogenicity of P. aeruginosa mainly depends upon biofilm and quorum sensing (QS) mechanism. Targeting biofilm and QS regulated factor will automatically reduce the pathogenicity of P. aeruginosa. Therefore it is compulsory to identify naturally derived biofilm and QS inhibitors against P. aeruginosa. In the present study Oscillatoria subuliformis, a marine cyanobacterium was used against the biofilm and QS of P...
November 27, 2017: Microbial Pathogenesis
Ashley L Nord, Emilie Gachon, Ruben Perez-Carrasco, Jasmine A Nirody, Alessandro Barducci, Richard M Berry, Francesco Pedaci
The bacterial flagellar motor (BFM) is the rotary motor that rotates each bacterial flagellum, powering the swimming and swarming of many motile bacteria. The torque is provided by stator units, ion motive force-powered ion channels known to assemble and disassemble dynamically in the BFM. This turnover is mechanosensitive, with the number of engaged units dependent on the viscous load experienced by the motor through the flagellum. However, the molecular mechanism driving BFM mechanosensitivity is unknown...
November 28, 2017: Proceedings of the National Academy of Sciences of the United States of America
Ismaël Duchesne, Tigran Galstian, Simon Rainville
Flagellated bacteria often proliferate in inhomogeneous environments, such as biofilms, swarms and soil. In such media, bacteria are observed to move efficiently only if they can get out of "dead ends" by changing drastically their swimming direction, and even to completely reverse it. Even though these reorientations are ubiquitous, we have only recently begun to describe and understand how they happen. In the present work, we visualized the flagella of bacteria swimming in a soft agar solution. The surprising observation that the filaments do not rotate while being flipped from one side of the cell to the other suggests that reversals are driven directly by the motor rather than by the thrust created by the rotating filament...
November 27, 2017: Scientific Reports
Jin-Cheng Ma, Yun-Qi Wu, Dan Cao, Wen-Bin Zhang, Hai-Hong Wang
The genome of Pseudomonas aeruginosa contains three open reading frames, PA2966, PA1869, and PA3334, which encode putative acyl carrier proteins, AcpP1, AcpP2, and AcpP3, respectively. In this study, we found that, although these apo-ACPs were successfully phosphopantetheinylated by P. aeruginosa phosphopantetheinyl transferase (PcpS) and all holo-forms of these proteins could be acylated by Vibrio harveyi acyl-ACP synthetase (AasS), only AcpP1 could be used as a substrate for the synthesis of fatty acids, catalyzed by P...
2017: Frontiers in Microbiology
S Cardinale, G Cambray
BACKGROUND: The pursuit of standardization and reliability in synthetic biology has achieved, in recent years, a number of advances in the design of more predictable genetic parts for biological circuits. However, even with the development of high-throughput screening methods and whole-cell models, it is still not possible to predict reliably how a synthetic genetic construct interacts with all cellular endogenous systems. This study presents a genome-wide analysis of how the expression of synthetic genes is affected by systematic perturbations of cellular functions...
November 23, 2017: BMC Systems Biology
Jin-Hyung Lee, Yong-Guy Kim, Sang Hee Shim, Jintae Lee
BACKGROUND: Bacterial biofilms exhibit reduced sensitivity to conventional antibiotics and host defence systems and contribute to the persistence of chronic bacterial infections. HYPOTHESIS: The antibiofilm approach using plant alkaloids provides an alternative to antibiotic strategies. STUDY DESIGN: In this study, the antibiofilm activities of various plant alkaloids were investigated against enterohemorrhagic Escherichia coli O157:H7 and Pseudomonas aeruginosa...
December 1, 2017: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Shuanghu Cai, Haiyan Cheng, Huanying Pang, Yishan Lu, Jichan Jian
A mutant strain of Vibiro alginolyticus with an in-frame deletion of the toxR gene was constructed to reveal the role of ToxR in the physiology and virulence of V. alginolyticus. The statistical analysis showed no significant difference in the growth ability, swarming motility, activity of extracellular protease and the virulence by injection (the value of LD50) between the wild-type and the toxR mutant. However, the deletion of toxR could decrease the level of biofilm formation. The comparative proteomic analysis demonstrated the deletion mutation of toxR could up-regulate the expression of glutamine synthetase and levansucrase, and down-regulate the expression of 10 proteins such as OmpU, DnaK, etc...
December 2017: Indian Journal of Microbiology
Ibtissem Chakroun, Abdelkarim Mahdhi, Patricia Morcillo, Hector Cordero, Alberto Cuesta, Amina Bakhrouf, Kacem Mahdouani, M Ángeles Esteban
Disease outbreaks related to waterborne pathogen contamination throughout the world as well as challenges that lie ahead for addressing persistent infection are of renewed interest. In this research, we studied the effects of prolonged exposure of Salmonella enterica serovar Typhimurium to the cues encountered in the extracellular environment particularly in seawater microcosm on bacterial virulence and subsequent infection in Caco-2 cells. Our data show a significant difference in biofilm formation, swimming and swarming motilities between normal and stressed cells of S...
November 13, 2017: Microbial Pathogenesis
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