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Lou F, Wang K, Hou Y, Shang X, Tang F. Inhibitory effect of resveratrol on swimming motility and adhesion ability against Salmonella enterica serovar Typhimurium infection. Microb Pathog 2023; 184:106323. [PMID: 37633505 DOI: 10.1016/j.micpath.2023.106323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
Salmonella enterica serovar Typhimurium (S. typhimurium) is a common Gram-negative foodborne pathogen that threatens public health and hinders the development of livestock industry. Resveratrol, an important component in grape fruits and seeds, has been shown to possess multiple biological activities, but its potential effects on S. typhimurium-mediated virulence have been rarely reported. In this study, we investigated the effect of resveratrol on S. typhimurium flagella -mediated virulence. The results showed that resveratrol significantly reduced the transcription of flagella genes and swimming motility of S. typhimurium, and also inhibited the transcription of T3SS-related virulence genes with varying degrees inhibiting bacterial growth. Simultaneously, resveratrol significantly reduced the adhesion of S. typhimurium to HeLa cells. Unfortunately, resveratrol does not improve the survival rate of S. typhimurium-infected mice, but it reduces the bacterial load in the liver and spleen of infected mice, and it also has a certain degree of anti-inflammatory activity. In summary, these results indicated that resveratrol has the potential to be developed as an alternative drug or antibacterial agent to prevent Salmonella infection.
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Affiliation(s)
- Fei Lou
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou, 450046, China
| | - Kunli Wang
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou, 450046, China
| | - Yunfeng Hou
- Shandong Jinzhuji Pharmaceuticals Co. Ltd., Jinan, 271100, Shandong, China
| | - Xiaolei Shang
- Shandong Jinzhuji Pharmaceuticals Co. Ltd., Jinan, 271100, Shandong, China
| | - Fayin Tang
- College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou, 450046, China.
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2
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Shelud'ko A, Volokhina I, Mokeev D, Telesheva E, Yevstigneeva S, Burov A, Tugarova A, Shirokov A, Burigin G, Matora L, Petrova L. Chromosomal gene of hybrid multisensor histidine kinase is involved in motility regulation in the rhizobacterium Azospirillum baldaniorum Sp245 under mechanical and water stress. World J Microbiol Biotechnol 2023; 39:336. [PMID: 37814195 DOI: 10.1007/s11274-023-03785-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/29/2023] [Indexed: 10/11/2023]
Abstract
Azospirillum alphaproteobacteria, which live in the rhizosphere of many crops, are used widely as biofertilizers. Two-component signal transduction systems (TCSs) mediate the bacterial perception of signals and the corresponding adjustment of behavior facilitating the adaptation of bacteria to their habitats. In this study, we obtained the A. baldaniorum Sp245 mutant for the AZOBR_150176 gene, which encodes the TCS of the hybrid histidine kinase/response sensory regulator (HSHK-RR). Inactivation of this gene affected bacterial morphology and motility. In mutant Sp245-HSHKΔRR-Km, the cells were still able to synthesize a functioning polar flagellum (Fla), were shorter than those of strain Sp245, and were impaired in aerotaxis, elaboration of inducible lateral flagella (Laf), and motility in semiliquid media. The mutant showed decreased transcription of the genes encoding the proteins of the secretion apparatus, which ensures the assembly of Laf, Laf flagellin, and the repressor protein of translation of the Laf flagellin's mRNA. The study examined the effects of polyethylene glycol 6000 (PEG 6000), an agent used to simulate osmotic stress and drought conditions. Under osmotic stress, the mutant was no longer able to use collective motility in semiliquid media but formed more biofilm biomass than did strain Sp245. Introduction into mutant cells of the AZOBR_150176 gene as part of an expression vector led to recovery of the lost traits, including those mediating bacterial motility under mechanical stress induced by increased medium density. The results suggest that the HSHK-RR under study modulates the response of A. baldaniorum Sp245 to mechanical and osmotic/water stress.
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Affiliation(s)
- Andrei Shelud'ko
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia.
| | - Irina Volokhina
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Dmitry Mokeev
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Elizaveta Telesheva
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Stella Yevstigneeva
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Andrei Burov
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Anna Tugarova
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Alexander Shirokov
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Gennady Burigin
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Larisa Matora
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
| | - Lilia Petrova
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, 410049, Russia
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3
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Piskovsky V, Oliveira NM. Bacterial motility can govern the dynamics of antibiotic resistance evolution. Nat Commun 2023; 14:5584. [PMID: 37696800 PMCID: PMC10495427 DOI: 10.1038/s41467-023-41196-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 08/24/2023] [Indexed: 09/13/2023] Open
Abstract
Spatial heterogeneity in antibiotic concentrations is thought to accelerate the evolution of antibiotic resistance, but current theory and experiments have overlooked the effect of cell motility on bacterial adaptation. Here, we study bacterial evolution in antibiotic landscapes with a quantitative model where bacteria evolve under the stochastic processes of proliferation, death, mutation and migration. Numerical and analytical results show that cell motility can both accelerate and decelerate bacterial adaptation by affecting the degree of genotypic mixing and ecological competition. Moreover, we find that for sufficiently high rates, cell motility can limit bacterial survival, and we derive conditions for all these regimes. Similar patterns are observed in more complex scenarios, namely where bacteria can bias their motion in chemical gradients (chemotaxis) or switch between motility phenotypes either stochastically or in a density-dependent manner. Overall, our work reveals limits to bacterial adaptation in antibiotic landscapes that are set by cell motility.
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Affiliation(s)
- Vit Piskovsky
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, UK
- Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK
| | - Nuno M Oliveira
- Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA, UK.
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
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4
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Masuku M, Mozirandi W, Mukanganyama S. Evaluation of the Antibacterial and Antibiofilm Effects of Ethyl Acetate Root Extracts from Vernonia adoensis (Asteraceae) against Pseudomonas aeruginosa. ScientificWorldJournal 2023; 2023:5782656. [PMID: 37324654 PMCID: PMC10264714 DOI: 10.1155/2023/5782656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/28/2023] [Accepted: 05/31/2023] [Indexed: 06/17/2023] Open
Abstract
There is an increase in mortality and morbidity in the health facilities due to nosocomial infections caused by multidrug-resistant nosocomial bacteria; hence, there is a need for new antibacterial agents. Vernonia adoensis has been found to possess medicinal value. Plant phytochemicals may have antimicrobial activity against some resistant pathogens. The antibacterial efficacy of root extracts against Staphylococcus aureus and Pseudomonas aeruginosa was investigated using the microbroth dilution method. All extracts from the roots had an inhibitory effect on the growth of both bacteria, with the most susceptible being P. aeruginosa. The most potent extract was the ethyl acetate extract which caused a percentage inhibition of 86% against P. aeruginosa. The toxicity of the extract was determined on sheep erythrocytes, and its effect on membrane integrity was determined by quantifying the amount of protein and nucleic acid leakage from the bacteria. The lowest concentration of extract used, which was 100 µg/ml, did not cause haemolysis of the erythrocytes, while at 1 mg/ml of the extract, 21% haemolysis was observed. The ethyl acetate extract caused membrane impairment of P. aeruginosa, leading to protein leakage. The effect of the extract on the biofilms of P. aeruginosa was determined in 96-microwell plates using crystal violet. In the concentration range of 0-100 µg/ml, the extract inhibited the formation of biofilms and decreased the attachment efficiency. The phytochemical constituents of the extract were determined using gas chromatography-mass spectrometry. Results of analysis showed the presence of 3-methylene-15-methoxy pentadecanol, 2-acetyl-6-(t-butyl)-4-methylphenol, 2-(2,2,3,3-tetrafluoropropanoyl) cyclohexane-1,4-dione, E,E,Z-1,3,12-nonadecatriene-5,14-diol, and stigmasta-5,22-dien-3-ol. Fractionation and purification will elucidate the potential antimicrobial compounds which are present in the roots of V. adoensis.
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Affiliation(s)
- Mercy Masuku
- Department of Biotechnology and Biochemistry, University of Zimbabwe, Mt. Pleasant, Harare, Zimbabwe
| | - Winnie Mozirandi
- Department of Biotechnology and Biochemistry, University of Zimbabwe, Mt. Pleasant, Harare, Zimbabwe
| | - Stanley Mukanganyama
- Department of Biotechnology and Biochemistry, University of Zimbabwe, Mt. Pleasant, Harare, Zimbabwe
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5
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Alonso-Vásquez T, Fondi M, Perrin E. Understanding Antimicrobial Resistance Using Genome-Scale Metabolic Modeling. Antibiotics (Basel) 2023; 12:antibiotics12050896. [PMID: 37237798 DOI: 10.3390/antibiotics12050896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/28/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
The urgent necessity to fight antimicrobial resistance is universally recognized. In the search of new targets and strategies to face this global challenge, a promising approach resides in the study of the cellular response to antimicrobial exposure and on the impact of global cellular reprogramming on antimicrobial drugs' efficacy. The metabolic state of microbial cells has been shown to undergo several antimicrobial-induced modifications and, at the same time, to be a good predictor of the outcome of an antimicrobial treatment. Metabolism is a promising reservoir of potential drug targets/adjuvants that has not been fully exploited to date. One of the main problems in unraveling the metabolic response of cells to the environment resides in the complexity of such metabolic networks. To solve this problem, modeling approaches have been developed, and they are progressively gaining in popularity due to the huge availability of genomic information and the ease at which a genome sequence can be converted into models to run basic phenotype predictions. Here, we review the use of computational modeling to study the relationship between microbial metabolism and antimicrobials and the recent advances in the application of genome-scale metabolic modeling to the study of microbial responses to antimicrobial exposure.
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Affiliation(s)
- Tania Alonso-Vásquez
- Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto F.no, 50019 Florence, Italy
| | - Marco Fondi
- Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto F.no, 50019 Florence, Italy
| | - Elena Perrin
- Department of Biology, University of Florence, Via Madonna del Piano 6, Sesto F.no, 50019 Florence, Italy
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6
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Bhattacharyya S, Bhattacharyya M, Pfannenstiel DM, Nandi AK, Hwang Y, Ho K, Harshey RM. Efflux-linked accelerated evolution of antibiotic resistance at a population edge. Mol Cell 2022; 82:4368-4385.e6. [PMID: 36400010 PMCID: PMC9699456 DOI: 10.1016/j.molcel.2022.10.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/22/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022]
Abstract
Efflux is a common mechanism of resistance to antibiotics. We show that efflux itself promotes accumulation of antibiotic-resistance mutations (ARMs). This phenomenon was initially discovered in a bacterial swarm where the linked phenotypes of high efflux and high mutation frequencies spatially segregated to the edge, driven there by motility. We have uncovered and validated a global regulatory network connecting high efflux to downregulation of specific DNA-repair pathways even in non-swarming states. The efflux-DNA repair link was corroborated in a clinical "resistome" database: genomes with mutations that increase efflux exhibit a significant increase in ARMs. Accordingly, efflux inhibitors decreased evolvability to antibiotic resistance. Swarms also revealed how bacterial populations serve as a reservoir of ARMs even in the absence of antibiotic selection pressure. High efflux at the edge births mutants that, despite compromised fitness, survive there because of reduced competition. This finding is relevant to biofilms where efflux activity is high.
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Affiliation(s)
- Souvik Bhattacharyya
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA.
| | | | - Dylan M Pfannenstiel
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Anjan K Nandi
- Department of Physical Sciences, Indian Institute of Science Education & Research, Kolkata, India
| | - YuneSahng Hwang
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Khang Ho
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA
| | - Rasika M Harshey
- Department of Molecular Biosciences and LaMontagne Center for Infectious Diseases, University of Texas at Austin, Austin, TX 78712, USA.
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7
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Abbas MA, Lee EB, Boby N, Biruhanu BT, Park SC. A pharmacodynamic investigation to assess the synergism of orbifloxacin and propyl gallate against Escherichia coli. Front Pharmacol 2022; 13:989395. [PMID: 36188537 PMCID: PMC9521280 DOI: 10.3389/fphar.2022.989395] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/24/2022] [Indexed: 11/26/2022] Open
Abstract
Escherichia coli (E. coli) infections are becoming increasingly difficult to treat, as antibiotic-resistant variants proliferate. Studies on novel methods to combat the spread of resistance and improve the performance of current antibiotics are vital. We aimed to boost the efficacy of the antibiotic orbifloxacin (ORB) against E. coli by combining it with a phenolic component, propyl gallate (PG). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ORB against the E. coli KVCC 1423 resistant strain were 128 μg/ml and 256 μg/ml, respectively. However, the MIC of ORB for the remaining E. coli strains was 0.5 μg/ml–2 μg/ml. For the combination of PG and ORB, the lowest fractional inhibitory concentration (FIC) index was less than 0.5, and the combination decreased the MIC of both drugs by 74%. The time-kill assay revealed the killing properties of both the drugs and the pharmacodynamic model (PD model) confirmed the strong killing properties of the combination as compared to the individual activities of the drugs. The ratio between MIC and mutant prevention concentration of ORB against E. coli 1400306 and 1,423 were 1:32 and 1:8, respectively. The combination of ORB and PG showed strong biofilm eradication and inhibited the motility of bacteria. The cell viability of the combination was > 80%. Therefore, we believe that ORB and PG in combination could be a possible antibacterial candidate that could minimize resistance and improve antibiotic potential.
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Affiliation(s)
- Muhammad Aleem Abbas
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, Cardiovascular Institute, College of Veterinary Medicine, Kyungpook National University, Daegu, Gyeongsangbuk-do, South Korea
| | - Eon-Bee Lee
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, Cardiovascular Institute, College of Veterinary Medicine, Kyungpook National University, Daegu, Gyeongsangbuk-do, South Korea
| | - Naila Boby
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, Cardiovascular Institute, College of Veterinary Medicine, Kyungpook National University, Daegu, Gyeongsangbuk-do, South Korea
| | - Biruk Tesfaye Biruhanu
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, Cardiovascular Institute, College of Veterinary Medicine, Kyungpook National University, Daegu, Gyeongsangbuk-do, South Korea
- *Correspondence: Biruk Tesfaye Biruhanu, ; Seung-Chun Park,
| | - Seung-Chun Park
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, Cardiovascular Institute, College of Veterinary Medicine, Kyungpook National University, Daegu, Gyeongsangbuk-do, South Korea
- Cardiovascular Research Institute, Kyungpook National University School of Medicine, Daegu, Gyeongsangbuk-do, South Korea
- *Correspondence: Biruk Tesfaye Biruhanu, ; Seung-Chun Park,
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8
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Formation of unique T-shape budding and differential impacts of low surface water on Bacillus mycoides rhizoidal colony. Arch Microbiol 2022; 204:528. [PMID: 35896814 DOI: 10.1007/s00203-022-03141-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/24/2022] [Accepted: 07/13/2022] [Indexed: 11/02/2022]
Abstract
Bacillus mycoides Ko01 strain grows rapidly and forms extensive rhizoidal colonies on hard agar despite limited surface water availability. The agar concentrations affect the handedness of the colonies as well as other colony architectures. In this study, we found that the local curvature of cell chains in the developing colonies did not vary based on the agar concentration, while concentration does affect the handedness of chirality at the macroscale. This result suggests independence between the microscale filament curvature and macroscale colony chirality. In addition, we discovered a novel microscopic property of cells that has not been observed before: T-shaped budding under extremely low surface water availability conditions. We propose that this feature gives rise to chaotic colony morphology. Together with bundling of chains, cells form a unique set of spatial arrangements under different surface water availability. These properties appear to impact the structural features of thick tendrils, and thereby the overall morphology of colonies. Our study provides additional insights as to how bacteria proliferate, spread, and develop macroscale colony architecture under water-limited conditions.
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Guard J. Through the Looking Glass: Genome, Phenome, and Interactome of Salmonella enterica. Pathogens 2022; 11:pathogens11050581. [PMID: 35631102 PMCID: PMC9144603 DOI: 10.3390/pathogens11050581] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 11/16/2022] Open
Abstract
This review revisits previous concepts on biological phenomenon contributing to the success of the Salmonella enterica subspecies I as a pathogen and expands upon them to include progress in epidemiology based on whole genome sequencing (WGS). Discussion goes beyond epidemiological uses of WGS to consider how phenotype, which is the biological character of an organism, can be correlated with its genotype to develop a knowledge of the interactome. Deciphering genome interactions with proteins, the impact of metabolic flux, epigenetic modifications, and other complex biochemical processes will lead to new therapeutics, control measures, environmental remediations, and improved design of vaccines.
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Affiliation(s)
- Jean Guard
- U. S. Department of Agriculture, Agricultural Research Service, U. S. National Poultry Research Center, 950 College Station Road, Athens, GA 30605, USA
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10
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N-acyl-homoserine lactone produced by Rahnella inusitata isolated from the gut of Galleria mellonella influences Salmonella phenotypes. Braz J Microbiol 2022; 53:819-829. [PMID: 35048318 PMCID: PMC9151966 DOI: 10.1007/s42770-022-00681-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 01/10/2022] [Indexed: 02/01/2023] Open
Abstract
The most studied mechanism of quorum sensing in Gram-negative bacteria is mediated by autoinducer 1 (AI-1), namely, acyl-homoserine lactone (AHL). This system allows communication among different bacterial species and regulates the expression of virulence genes in many pathogens. Although AHL-producing bacteria have been detected in the intestines of humans and other animals, no report was found about AHL-producing bacteria in the insect gut and the possible effects of these autoinducers on enteropathogenic bacteria. Therefore, this study aimed to identify AHL-producing bacteria in the gut of larvae of Galleria mellonella and to evaluate the influence of this quorum sensing signal on the regulation of adhesion and motility phenotypes in the intestinal pathogen Salmonella. Sequencing of the 16S rRNA gene, 16S rRNA gene-based phylogenetic analyses, and phenotypic characterization of gut isolates was performed. The profile of AHLs produced by the isolates was determined using thin-layer chromatography (TLC) and revealed with the biosensor strain Chromobacterium violaceum CV026. Sequencing, phylogenetic analyses and phenotypic characterization of gut isolates showed that the three AHL-producing strains belong to the species Rahnella inusitata, named GM34, GM56, and GM60. The TLC showed that R. inusitata produces a six-carbon AHL. In the presence of cell-free extract of R. inusitata containing AHL and under anaerobic conditions, Salmonella enterica increased the adhesion to stainless steel coupons and presented swarming motility. Extracts from the culture medium of R. inusitata isolates containing AHL increased the adhesion on stainless steel coupons and swarming motility of Salmonella enterica serovar Enteritidis PT4 under anaerobic conditions. The results suggest the possibility of communication between members of the G. mellonella intestinal microbiota with pathogens such as Salmonella.
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Culture dependent and independent detection of multiple extended beta-lactamase producing and biofilm forming Salmonella species from leafy vegetables. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.102202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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12
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Gazel D, Zer Y, Büyüktaş Manay A, Akdoğan H. Inhibition of swarming motility using in vitro hyperthermia. J Therm Biol 2021; 100:102955. [PMID: 34503816 DOI: 10.1016/j.jtherbio.2021.102955] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/03/2021] [Accepted: 04/03/2021] [Indexed: 11/16/2022]
Abstract
Hyperthermia is a therapeutic technique in which body tissue is exposed to temperatures in the region of 40-45 °C to induce a physiological or biological effect. Swarming motility is an important virulence factor for Proteus mirabilis and Pseudomonas aeruginosa and swarming phenomenon is a coordinated multicellular movement of differentiated bacterial population over semi-solid surfaces. In this study, we aimed to investigate the inhibitory effect of hyperthermia on bacterial swarming motility using a modified thermobiogram method and show the potential of this thermal method to treat bacterial infections. Ten P. mirabilis and 10 P. aeruginosa clinical isolates were included in the study. Sheep blood agar (SBA) plates were prepared and inoculated with bacterial suspensions of clinical isolates. Inoculated SBA plates were incubated inside 2 different incubators; at 37 °C and 45 °C for 20 h. The diameter of bacterial growing zones (swarming diameters) were measured every 2 h and noted. Finally, Gram stains of the isolates were prepared for microscopic examination. Wilcoxon signed-rank test was used to compare the swarming inhibition rates of the isolates incubated at 37 °C and 45 °C. Regarding P. mirabilis species, a significant difference was found between two different temperatures (P = 0.0078). So, a temperature at the level of hyperthermia significantly inhibited the swarming motility of P. mirabilis isolates. In addition, transformation to coccus form was observed at 45 °C. We speculate that these findings might be useful for employing thermal therapies including hyperthermia method to treat infectious diseases caused by swarming bacterial pathogens in the future.
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Affiliation(s)
- Deniz Gazel
- Department of Medical Microbiology, Gaziantep University, Faculty of Medicine, Gaziantep, Turkey.
| | - Yasemin Zer
- Department of Medical Microbiology, Gaziantep University, Faculty of Medicine, Gaziantep, Turkey.
| | - Ayşe Büyüktaş Manay
- Department of Medical Microbiology, Gaziantep University, Faculty of Medicine, Gaziantep, Turkey.
| | - Hüseyin Akdoğan
- Department of Medical Microbiology, Gaziantep University, Faculty of Medicine, Gaziantep, Turkey.
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Gazel D, Demirbakan H, Erinmez M. In vitro activity of hyperthermia on swarming motility and antimicrobial susceptibility profiles of Proteus mirabilis isolates. Int J Hyperthermia 2021; 38:1002-1012. [PMID: 34180748 DOI: 10.1080/02656736.2021.1943546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
AIM Swarming motility is a virulence factor for Proteus mirabilis and is a coordinated multicellular movement of bacteria. In this study, we investigated the inhibitory effect of hyperthermia on bacterial swarming motility and antimicrobial resistance. METHODS Thirty-one P. mirabilis isolates were included in the study. Seven inoculated agar plates were incubated inside incubators with increasing temperature levels: at 36 °C (control) and 40-45 °C. On the next day, inhibition of swarming was evaluated and minimum paralyzing temperature (MPT) values were determined. An antimicrobial susceptibility test (antibiogram) is performed by exposing bacteria to increasing concentrations of antibiotics, in vitro. Thus, we used the Kirby-Bauer disk diffusion test as a screening method to analyze the antibiogram profiles of the isolates at 36 °C and 42 °C. Finally, a time-kill assay was performed to analyze the killing effect of hyperthermia (42 °C) on planktonic bacteria, in combination with the antibiotic meropenem at the first and third hours. A Wilcoxon signed-rank test was used to compare the killing effects of meropenem, hyperthermia and their combinations. RESULTS The median MPT value was determined as 44 °C. In the disk diffusion assay, susceptibility development was observed in 94% of isolates for at least one antibiotic. In the time-kill assay, we observed a significant killing effect of hyperthermia in combination with meropenem. Under the microscope, we observed the formation of spherical cells by the effect of heat. CONCLUSION We conclude that these findings might be useful when employing the hyperthermia method to treat infectious diseases caused by P. mirabilis in the future.
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Affiliation(s)
- Deniz Gazel
- Faculty of Medicine, Department of Medical Microbiology, Gaziantep University, Gaziantep, Turkey
| | - Hadiye Demirbakan
- Faculty of Medicine, Department of Medical Microbiology, Sanko University, Gaziantep, Turkey
| | - Mehmet Erinmez
- Faculty of Medicine, Department of Medical Microbiology, Gaziantep University, Gaziantep, Turkey
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The Nutrient and Energy Pathway Requirements for Surface Motility of Nonpathogenic and Uropathogenic Escherichia coli. J Bacteriol 2021; 203:JB.00467-20. [PMID: 33782053 PMCID: PMC8117529 DOI: 10.1128/jb.00467-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Uropathogenic E. coli (UPEC) is the causative pathogen for most uncomplicated urinary tract infections. Motility is likely to contribute to these infections, and E. coli possesses flagella-dependent swimming motility, flagella-dependent surface motility (often called swarming), and the recently observed pili-dependent surface motility. Surface motility has not been extensively studied, but for the strains that have been tested nonpathogenic E. coli (NPEC) lab strains use pili, NPEC hypermotile derivatives of these lab strains use flagella, and UPEC strains use flagella. Using a representative of these three types of strains, we showed differences in the nutritional and pathway requirements for surface motility with respect to the glucose concentration, the glycolytic pathway utilized, acetogenesis, and the TCA cycle. In addition, glucose controlled flagella synthesis for the NPEC strain, but not for the hypermotile NPEC variant or the UPEC strain. The requirements for surface motility are likely to reflect major metabolic differences between strains for the pathways and regulation of energy metabolism.IMPORTANCEUrinary tract infections (UTIs) are one of the most common bacterial infections and are an increasing burden on the healthcare system because of recurrence and antibiotic resistance (1, 2). The most common uropathogen is E. coli (3, 4), which is responsible for about 80-90% of community acquired UTIs and 40-50% of nosocomial acquired UTIs (2). Virulence requires both pili and flagella, and either appendage can contribute to surface motility, although surface motility of uropathogenic E. coli has not been examined. We found different appendage, nutrient and pathway requirements for surface motility of a nonpathogenic E. coli lab strain and a uropathogenic E. coli We propose that these differences are the result of differences in the pathways and regulation of energy metabolism.
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Ganusova EE, Vo LT, Mukherjee T, Alexandre G. Multiple CheY Proteins Control Surface-Associated Lifestyles of Azospirillum brasilense. Front Microbiol 2021; 12:664826. [PMID: 33968002 PMCID: PMC8100600 DOI: 10.3389/fmicb.2021.664826] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 03/29/2021] [Indexed: 12/18/2022] Open
Abstract
Bacterial chemotaxis is the directed movement of motile bacteria in gradients of chemoeffectors. This behavior is mediated by dedicated signal transduction pathways that couple environment sensing with changes in the direction of rotation of flagellar motors to ultimately affect the motility pattern. Azospirillum brasilense uses two distinct chemotaxis pathways, named Che1 and Che4, and four different response regulators (CheY1, CheY4, CheY6, and CheY7) to control the swimming pattern during chemotaxis. Each of the CheY homologs was shown to differentially affect the rotational bias of the polar flagellum and chemotaxis. The role, if any, of these CheY homologs in swarming, which depends on a distinct lateral flagella system or in attachment is not known. Here, we characterize CheY homologs’ roles in swimming, swarming, and attachment to abiotic and biotic (wheat roots) surfaces and biofilm formation. We show that while strains lacking CheY1 and CheY6 are still able to navigate air gradients, strains lacking CheY4 and CheY7 are chemotaxis null. Expansion of swarming colonies in the presence of gradients requires chemotaxis. The induction of swarming depends on CheY4 and CheY7, but the cells’ organization as dense clusters in productive swarms appear to depend on functional CheYs but not chemotaxis per se. Similarly, functional CheY homologs but not chemotaxis, contribute to attachment to both abiotic and root surfaces as well as to biofilm formation, although these effects are likely dependent on additional cell surface properties such as adhesiveness. Collectively, our data highlight distinct roles for multiple CheY homologs and for chemotaxis on swarming and attachment to surfaces.
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Affiliation(s)
- Elena E Ganusova
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, United States
| | - Lam T Vo
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, United States
| | - Tanmoy Mukherjee
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, United States
| | - Gladys Alexandre
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, United States
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Synergism of the Combination of Traditional Antibiotics and Novel Phenolic Compounds against Escherichia coli. Pathogens 2020; 9:pathogens9100811. [PMID: 33023003 PMCID: PMC7600547 DOI: 10.3390/pathogens9100811] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 12/12/2022] Open
Abstract
Pathogenic Escherichia coli (E. coli)-associated infections are becoming difficult to treat because of the rapid emergence of antibiotic-resistant strains. Novel approaches are required to prevent the progression of resistance and to extend the lifespan of existing antibiotics. This study was designed to improve the effectiveness of traditional antibiotics against E. coli using a combination of the gallic acid (GA), hamamelitannin, epicatechin gallate, epigallocatechin, and epicatechin. The fractional inhibitory concentration index (FICI) of each of the phenolic compound-antibiotic combinations against E. coli was ascertained. Considering the clinical significance and FICI, two combinations (hamamelitannin-erythromycin and GA-ampicillin) were evaluated for their impact on certain virulence factors of E. coli. Finally, the effects of hamamelitannin and GA on Rattus norvegicus (IEC-6) cell viability were investigated. The FICIs of the antibacterial combinations against E. coli were 0.281-1.008. The GA-ampicillin and hamamelitannin-erythromycin combinations more effectively prohibited the growth, biofilm viability, and swim and swarm motilities of E. coli than individual antibiotics. The concentration of hamamelitannin and GA required to reduce viability by 50% (IC50) in IEC-6 cells was 988.54 μM and 564.55 μM, correspondingly. GA-ampicillin and hamamelitannin-erythromycin may be potent combinations and promising candidates for eradicating pathogenic E. coli in humans and animals.
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Limsuwan S, Jarukitsakul S, Issuriya A, Chusri S, Joycharat N, Jaisamut P, Saising J, Jetwanna KWN, Voravuthikunchai SP. Thai herbal formulation 'Ya-Pit-Samut-Noi': Its antibacterial activities, effects on bacterial virulence factors and in vivo acute toxicity. JOURNAL OF ETHNOPHARMACOLOGY 2020; 259:112975. [PMID: 32417424 DOI: 10.1016/j.jep.2020.112975] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/29/2020] [Accepted: 05/10/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE A Thai herbal formulation 'Ya-Pit-Samut-Noi' containing Nigella sativa (seed), Piper retrofractum (fruit), Punica granatum (pericarp), and Quercus infectoria (nutgall) has long been traditionally used to treat diarrhea or bloody mucous diarrhea. Scientific information is very important to support its therapeutic effects and traditional drug development. AIM OF THE STUDY This study aimed to evaluate the antibacterial activities of Ya-Pit-Samut-Noi against diarrhea-causing bacteria and determine its effects on bacterial virulence factors and in vivo acute toxicity. MATERIALS AND METHODS Ethanol and water extracts of Ya-Pit-Samut-Noi and its plant components were prepared. The agar diffusion method was used for preliminary screening of antibacterial activity of the extracts against diarrhea-causing bacteria including Staphylococcus aureus, Vibrio cholerae, and Vibrio parahaemolyticus. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were assessed using broth microdilution method. The effects on bactericidal activity, bacterial cell wall, and cell membrane were examined by time-kill, lysis, and leakage assays, respectively. The effects on bacterial virulence factors including quorum-sensing system, biofilm production, and swarming motility were determined. Phytochemical screening was carried out to identify the group of chemical compounds present in the formulation extracts. Acute toxicity study was conducted by a single oral dose of 2000 mg/kg body weight in Wistar albino rats. RESULTS Ethanol and water extracts of Ya-Pit-Samut-Noi and Quercus infectoria demonstrated antibacterial efficacy against all bacterial strains as revealed by zones of inhibition ranging from 7.0 to 24.5 mm. The ethanol and water extracts of Ya-Pit-Samut-Noi and Quercus infectoria produced strong bacteriostatic activity against V. parahaemolyticus (n = 11) with an MIC range of 7.81-250 μg/ml. Only the ethanol extract of Ya-Pit-Samut-Noi produced MBC values less than or equal to 1000 μg/ml against all V. parahaemolyticus. Based on time-kill study, no surviving V. parahaemolyticus (ATCC 17802 and 5268) cells were detected within 6-12 h after treatment with the ethanol extract of Ya-Pit-Samut-Noi at MBC-4MBC concentrations. Vibrioparahaemolyticus ATCC 17802 cells treated with the ethanol extract of Ya-Pit-Samut-Noi demonstrated no lysis or leakage through the bacterial membrane was not observed. At low concentrations (0.125-0.25 μg/ml) the ethanol extract of Ya-Pit-Samut-Noi inhibited violacein production by Chromobacterium violaceum DMST 21761 without affecting the bacterial growth. The ethanol (31.25-62.5 μg/ml) and water (31.25-250 μg/ml) extracts of Ya-Pit-Samut-Noi inhibited biofilm production by S. aureus. The ethanol and water extracts of Ya-Pit-Samut-Noi at 1000 μg/ml reduced the swarming motility of Escherichia coli O157: H7 by 74.98% and 52.65%, respectively. Tannins and terpenoids were detected in both the ethanol and water extracts. Flavonoids were present only in the ethanol extract. Alkaloids and antraquinones were not noticed in either extract. In the acute toxicity study, there were no significant changes in hematological and biochemical parameters nor were adverse effects on mortality, general behaviors, body weight, or organ weights detected. CONCLUSIONS The scientific evidence from this study supported the therapeutic effects and safety of the traditional Thai herbal formulation 'Ya-Pit-Samut-Noi' which has been used as an alternative treatment for gastrointestinal infections in Thailand.
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Affiliation(s)
- Surasak Limsuwan
- Faculty of Traditional Thai Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand; Excellence Research Laboratory on Natural Products, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
| | - Siriporn Jarukitsakul
- Faculty of Traditional Thai Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Acharaporn Issuriya
- Department of Physiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Sasitorn Chusri
- Faculty of Traditional Thai Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand; Excellence Research Laboratory on Natural Products, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Nantiya Joycharat
- Faculty of Traditional Thai Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand; Excellence Research Laboratory on Natural Products, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Patcharawalai Jaisamut
- Faculty of Traditional Thai Medicine, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Jongkon Saising
- School of Health Science, Mae Fah Luang University, Muang, Chiang Rai, 57100, Thailand
| | - Korakot Wichitsa-Nguan Jetwanna
- Department of Mathematics and Statistics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Supayang Piyawan Voravuthikunchai
- Excellence Research Laboratory on Natural Products, Faculty of Science and Natural Product Research Center of Excellence, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand; Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
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Bhattacharyya S, Walker DM, Harshey RM. Dead cells release a 'necrosignal' that activates antibiotic survival pathways in bacterial swarms. Nat Commun 2020; 11:4157. [PMID: 32814767 PMCID: PMC7438516 DOI: 10.1038/s41467-020-17709-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 07/14/2020] [Indexed: 01/06/2023] Open
Abstract
Swarming is a form of collective bacterial motion enabled by flagella on the surface of semi-solid media. Swarming populations exhibit non-genetic or adaptive resistance to antibiotics, despite sustaining considerable cell death. Here, we show that antibiotic-induced death of a sub-population benefits the swarm by enhancing adaptive resistance in the surviving cells. Killed cells release a resistance-enhancing factor that we identify as AcrA, a periplasmic component of RND efflux pumps. The released AcrA interacts on the surface of live cells with an outer membrane component of the efflux pump, TolC, stimulating drug efflux and inducing expression of other efflux pumps. This phenomenon, which we call 'necrosignaling', exists in other Gram-negative and Gram-positive bacteria and displays species-specificity. Given that adaptive resistance is a known incubator for evolving genetic resistance, our findings might be clinically relevant to the rise of multidrug resistance.
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Affiliation(s)
- Souvik Bhattacharyya
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - David M Walker
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Rasika M Harshey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
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19
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Vishwakarma J, V.L S. Unraveling the anti-biofilm potential of green algal sulfated polysaccharides against Salmonella enterica and Vibrio harveyi. Appl Microbiol Biotechnol 2020; 104:6299-6314. [DOI: 10.1007/s00253-020-10653-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 04/08/2020] [Accepted: 04/29/2020] [Indexed: 01/06/2023]
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20
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Hossain MA, Park HC, Lee KJ, Park SW, Park SC, Kang J. In vitro synergistic potentials of novel antibacterial combination therapies against Salmonella enterica serovar Typhimurium. BMC Microbiol 2020; 20:118. [PMID: 32410630 PMCID: PMC7227263 DOI: 10.1186/s12866-020-01810-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 05/03/2020] [Indexed: 01/08/2023] Open
Abstract
Background The antibiotics generally used in farm animals are rapidly losing their effectiveness all over the world as bacteria develop antibiotic resistance. Like some other pathogenic bacteria multidrug-resistant strains of Salmonella enterica serovar Typhimurium (S. Typhimurium) are also frequently found in animals and humans which poses a major public health concern. New strategies are needed to block the development of resistance and to prolong the life of traditional antibiotics. Thus, this study aimed to increase the efficacy of existing antibiotics against S. Typhimurium by combining them with opportunistic phenolic compounds gallic acid (GA), epicatechin, epicatechin gallate, epigallocatechin and hamamelitannin. Fractional inhibitory concentration indexes (FICI) of phenolic compound-antibiotic combinations against S. Typhimurium were determined. Based on the FICI and clinical importance, 1 combination (GA and ceftiofur) was selected for evaluating its effects on the virulence factors of this bacterium. Viability of Rattus norvegicus (IEC-6) cell in presence of this antibacterial combination was evaluated. Results Minimum inhibitory concentrations (MICs) of GA, epigallocatechin and hamamelitannin found against different strains of S. Typhimurium were 256, (512–1024), and (512–1024) μg/mL, respectively. Synergistic antibacterial effect was obtained from the combination of erythromycin-epicatechin gallate (FICI: 0.50) against S. Typhimurium. Moreover, additive effects (FICI: 0.502–0.750) were obtained from 16 combinations against this bacterium. The time-kill assay and ultrastructural morphology showed that GA-ceftiofur combination more efficiently inhibited the growth of S. Typhimurium compared to individual antimicrobials. Biofilm viability, and swimming and swarming motilities of S. Typhimurium in presence of GA-ceftiofur combination were more competently inhibited than individual antimicrobials. Viabilities of IEC-6 cells were more significantly enhanced by GA-ceftiofur combinations than these antibacterials alone. Conclusions This study suggests that GA-ceftiofur combination can be potential medication to treat S. Typhimurium-associated diarrhea and prevent S. Typhimurium-associated blood-stream infections (e.g.: fever) in farm animals, and ultimately its transmission from animal to human. Further in vivo study to confirm these effects and safety profiles in farm animal should be undertaken for establishing these combinations as medications.
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Affiliation(s)
- Md Akil Hossain
- Veterinary Drugs & Biologics Division, Animal and Plant Quarantine Agency, Gimcheon-si, 39660, Republic of Korea
| | - Hae-Chul Park
- Veterinary Drugs & Biologics Division, Animal and Plant Quarantine Agency, Gimcheon-si, 39660, Republic of Korea
| | - Kwang-Jick Lee
- Veterinary Drugs & Biologics Division, Animal and Plant Quarantine Agency, Gimcheon-si, 39660, Republic of Korea
| | - Sung-Won Park
- Veterinary Drugs & Biologics Division, Animal and Plant Quarantine Agency, Gimcheon-si, 39660, Republic of Korea
| | - Seung-Chun Park
- Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Bukgu, Daegu, 41566, Republic of Korea
| | - JeongWoo Kang
- Veterinary Drugs & Biologics Division, Animal and Plant Quarantine Agency, Gimcheon-si, 39660, Republic of Korea.
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21
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Dynamic motility selection drives population segregation in a bacterial swarm. Proc Natl Acad Sci U S A 2020; 117:4693-4700. [PMID: 32060120 DOI: 10.1073/pnas.1917789117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Population expansion in space, or range expansion, is widespread in nature and in clinical settings. Space competition among heterogeneous subpopulations during range expansion is essential to population ecology, and it may involve the interplay of multiple factors, primarily growth and motility of individuals. Structured microbial communities provide model systems to study space competition during range expansion. Here we use bacterial swarms to investigate how single-cell motility contributes to space competition among heterogeneous bacterial populations during range expansion. Our results revealed that motility heterogeneity can promote the spatial segregation of subpopulations via a dynamic motility selection process. The dynamic motility selection is enabled by speed-dependent persistence time bias of single-cell motion, which presumably arises from physical interaction between cells in a densely packed swarm. We further showed that the dynamic motility selection may contribute to collective drug tolerance of swarming colonies by segregating subpopulations with transient drug tolerance to the colony edge. Our results illustrate that motility heterogeneity, or "motility fitness," can play a greater role than growth rate fitness in determining the short-term spatial structure of expanding populations.
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22
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Dávila-Aviña J, Gil-Solís C, Merino-Mascorro J, García S, Heredia N. Phenolics with Bactericidal Activity Alter Motility and Biofilm Formation in Enterotoxigenic, Enteropathogenic, and Enterohemorrhagic Escherichia coli. Foodborne Pathog Dis 2020; 17:568-575. [PMID: 32043899 DOI: 10.1089/fpd.2019.2766] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Most Escherichia coli strains are innocuous to human beings; however, some strains can cause diarrhea and are grouped into pathotypes. Since current trends promote the use of natural-origin compounds to control bacteria, in this study, the effects of the phenolic compounds (PCs) tannic acid (TA), gallic acid (GA), methyl gallate (MG), and epigallocatechin gallate (EG) on the growth, swarming motility, biofilm formation, and expression of selected virulence genes of three E. coli pathotypes (enteropathogenic Escherichia coli [EPEC], enterohemorrhagic Escherichia coli [EHEC], and enterotoxigenic Escherichia coli [ETEC]) were evaluated. Minimum bactericidal concentrations (MBCs) were determined by using microtiter plates, and the effects of sublethal PC concentrations on swarming motility were evaluated on Luria-Bertani agar. Biofilm formation was assessed in microtiter plates via crystal violet staining, and the expression levels of genes involved in biofilm formation (flhC, fliA, fliC, and csgA) and swarming motility (csgD and cyaA) were evaluated via quantitative PCR. All PC were bactericidal with minimal bactericidal concentrations ranging from 0.07 to 2.1 mg/mL. At concentrations lower than the MBC, PCs decreased swarming motility (14.8-100%). GA reduced biofilm formation in all of the tested strains; however, TA, MG, and EG induced biofilm formation in some strains at specific concentrations. TA induced the overexpression of csgA, csgD, and cyaA, whereas the other PCs did not have any effects or reduced their expression levels. The PCs tested in this study showed potential to control E. coli strains belonging to the EHEC, ETEC, and EPEC pathotypes by affecting their growth, swarming motility, and virulence gene expression; however, proper concentrations must be used to avoid the induction of undesirable virulence factor genes.
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Affiliation(s)
- Jorge Dávila-Aviña
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Carolina Gil-Solís
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Jose Merino-Mascorro
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Santos García
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
| | - Norma Heredia
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, México
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PQS Produced by the Pseudomonas aeruginosa Stress Response Repels Swarms Away from Bacteriophage and Antibiotics. J Bacteriol 2019; 201:JB.00383-19. [PMID: 31451543 DOI: 10.1128/jb.00383-19] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 08/21/2019] [Indexed: 11/20/2022] Open
Abstract
We investigate the effect of bacteriophage infection and antibiotic treatment on the coordination of swarming, a collective form of flagellum- and pilus-mediated motility in bacteria. We show that phage infection of the opportunistic bacterial pathogen Pseudomonas aeruginosa abolishes swarming motility in the infected subpopulation and induces the release of the Pseudomonas quinolone signaling molecule PQS, which repulses uninfected subpopulations from approaching the infected area. These mechanisms have the overall effect of limiting the infection to a subpopulation, which promotes the survival of the overall population. Antibiotic treatment of P. aeruginosa elicits the same response, abolishing swarming motility and repulsing approaching swarms away from the antibiotic-treated area through a PQS-dependent mechanism. Swarms are entirely repelled from the zone of antibiotic-treated P. aeruginosa, consistent with a form of antibiotic evasion, and are not repelled by antibiotics alone. PQS has multiple functions, including serving as a quorum-sensing molecule, activating an oxidative stress response, and regulating the release of virulence and host-modifying factors. We show that PQS serves additionally as a stress warning signal that causes the greater population to physically avoid cell stress. The stress response at the collective level observed here in P. aeruginosa is consistent with a mechanism that promotes the survival of bacterial populations.IMPORTANCE We uncover a phage- and antibiotic-induced stress response in the clinically important opportunistic pathogen Pseudomonas aeruginosa Phage-infected P. aeruginosa subpopulations are isolated from uninfected subpopulations by the production of a stress-induced signal. Activation of the stress response by antibiotics causes P. aeruginosa to physically be repelled from the area containing antibiotics altogether, consistent with a mechanism of antibiotic evasion. The stress response observed here could increase P. aeruginosa resilience against antibiotic treatment and phage therapy in health care settings, as well as provide a simple evolutionary strategy to avoid areas containing stress.
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Bacterial Swarming Reduces Proteus mirabilis and Vibrio parahaemolyticus Cell Stiffness and Increases β-Lactam Susceptibility. mBio 2019; 10:mBio.00210-19. [PMID: 31594808 PMCID: PMC6786863 DOI: 10.1128/mbio.00210-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteus mirabilis and Vibrio parahaemolyticus are bacteria that infect humans. To adapt to environmental changes, these bacteria alter their cell morphology and move collectively to access new sources of nutrients in a process referred to as “swarming.” We found that changes in the composition and thickness of the peptidoglycan layer of the cell wall make swarmer cells of P. mirabilis and V. parahaemolyticus more flexible (i.e., reduce cell stiffness) and that they become more sensitive to osmotic pressure and cell wall-targeting antibiotics (e.g., β-lactams). These results highlight the importance of assessing the extracellular environment in determining antibiotic doses and the use of β-lactam antibiotics for treating infections caused by swarmer cells of P. mirabilis and V. parahaemolyticus. Swarmer cells of the Gram-negative uropathogenic bacteria Proteus mirabilis and Vibrio parahaemolyticus become long (>10 to 100 μm) and multinucleate during their growth and motility on polymer surfaces. We demonstrated that the increasing cell length is accompanied by a large increase in flexibility. Using a microfluidic assay to measure single-cell mechanics, we identified large differences in the swarmer cell stiffness (bending rigidity) of P. mirabilis (5.5 × 10−22 N m2) and V. parahaemolyticus (1.0 × 10−22 N m2) compared to vegetative cells (1.4 × 10−20 N m2 and 2.2 × 10−22 N m2, respectively). The reduction in bending rigidity (∼2-fold to ∼26-fold) was accompanied by a decrease in the average polysaccharide strand length of the peptidoglycan layer of the cell wall from 28 to 30 disaccharides to 19 to 22 disaccharides. Atomic force microscopy revealed a reduction in P. mirabilis peptidoglycan thickness from 1.5 nm (vegetative cells) to 1.0 nm (swarmer cells), and electron cryotomography indicated changes in swarmer cell wall morphology. P. mirabilis and V. parahaemolyticus swarmer cells became increasingly sensitive to osmotic pressure and susceptible to cell wall-modifying antibiotics (compared to vegetative cells)—they were ∼30% more likely to die after 3 h of treatment with MICs of the β-lactams cephalexin and penicillin G. The adaptive cost of “swarming” was offset by the increase in cell susceptibility to physical and chemical changes in their environment, thereby suggesting the development of new chemotherapies for bacteria that leverage swarming for the colonization of hosts and for survival.
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25
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Ligowska-Marzęta M, Hancock V, Ingmer H, M Aarestrup F. Comparison of Gene Expression Profiles of Uropathogenic Escherichia Coli CFT073 after Prolonged Exposure to Subinhibitory Concentrations of Different Biocides. Antibiotics (Basel) 2019; 8:antibiotics8040167. [PMID: 31569631 PMCID: PMC6963283 DOI: 10.3390/antibiotics8040167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/19/2019] [Accepted: 09/23/2019] [Indexed: 01/24/2023] Open
Abstract
Biocides are chemical compounds widely used for sterilization and disinfection. The aim of this study was to examine whether exposure to subinhibitory biocide concentrations influenced transcriptional expression of genes that could improve a pathogen’s drug resistance or fitness. We used DNA microarrays to investigate the transcriptome of the uropathogenic Escherichia coli strain CFT073 in response to prolonged exposure to subinhibitory concentrations of four biocides: benzalkonium chloride, chlorhexidine, hydrogen peroxide and triclosan. Transcription of a gene involved in polymyxin resistance, arnT, was increased after treatment with benzalkonium chloride. However, pretreatment of the bacteria with this biocide did not result in cross-resistance to polymyxin in vitro. Genes encoding products related to transport formed the functional group that was most affected by biocides, as 110 out of 884 genes in this category displayed altered transcription. Transcripts of genes involved in cysteine uptake, sulfate assimilation, dipeptide transport, as well as cryptic phage genes were also more abundant in response to several biocides. Additionally, we identified groups of genes with transcription changes unique to single biocides that might include potential targets for the biocides. The biocides did not increase the resistance potential of the pathogen to other antimicrobials.
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Affiliation(s)
- Małgorzata Ligowska-Marzęta
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark.
- Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Viktoria Hancock
- Renal Research & Innovation, Baxter International Inc., SE-220 10 Lund, Sweden.
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark.
| | - Frank M Aarestrup
- Research Group for Genomic Epidemiology, National Food Institute, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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Ross BN, Micheva-Viteva S, Hong-Geller E, Torres AG. Evaluating the role of Burkholderia pseudomallei K96243 toxins BPSS0390, BPSS0395, and BPSS1584 in persistent infection. Cell Microbiol 2019; 21:e13096. [PMID: 31400259 DOI: 10.1111/cmi.13096] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 08/07/2019] [Accepted: 08/08/2019] [Indexed: 01/01/2023]
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, a disease with a mortality rate of up to 40% even with treatment. Despite the ability of certain antibiotics to control initial infection, relapse occurs in treated patients. The inability of antibiotics to clear this bacterial infection is in part due to persistence, an evasion mechanism against antibiotics and the effect of host defenses. Evaluation of antibiotic efficacy against B. pseudomallei revealed that up to 48% of in vitro grown populations can survive in a persister state. Toxin-antitoxin (TA) systems have been previously implicated in modulating bacterial persistence. We generated three isogenic TA mutants and found that loss of each toxin gene did not alter antibiotic persistence or macrophage survival. In response to macrophage-induced persistence, all three toxin mutants demonstrated increased intracellular susceptibility to levofloxacin which in part was due to the inability of the mutants to induce persistence after nitric oxide or nutrient starvation. In an inhalational model of murine melioidosis, both ΔBPSS0395 and ΔBPSS1584 strains were attenuated, and treatment with levofloxacin led to significant reduction in lung colonisation and reduced splenic colonisation by ΔBPSS0395. Based on our findings, these toxins deserve additional evaluation as putative therapeutic targets.
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Affiliation(s)
- Brittany N Ross
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | | | | | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas
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Kroupitski Y, Gollop R, Belausov E, Pinto R, Sela Saldinger S. Salmonella enterica Growth Conditions Influence Lettuce Leaf Internalization. Front Microbiol 2019; 10:639. [PMID: 31057491 PMCID: PMC6482241 DOI: 10.3389/fmicb.2019.00639] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 03/13/2019] [Indexed: 11/21/2022] Open
Abstract
Human pathogens on plants (HPOP) have evolved complex interactions with their plant host. Stomatal internalization is one such mode of interaction, where bacteria are attracted to stomata and penetrate into the substomatal cavity by a process mediated by chemotaxis. Internalization enables HPOP to evade the hostile environment of the leaf surface and find a protected, nutrient-rich niche within the leaf. Numerous studies have documented attachment and entry of the foodborne pathogens, Salmonella enterica and Escherichia coli into stomata. Internalization, however, varies considerably among different pathogens and in different plants, and both bacterial and plant’s factors were reported to influence HPOP attachment and internalization. Here we have studied the effect of laboratory growth conditions, on the internalization of Salmonella enterica serovar Typhimurium (STm) into lettuce leaf. We have further tested the potential involvement of universal stress-proteins in leaf internalization. We found that STm grown in Luria Bertani broth devoid of NaCl (LBNS), or in diluted LB (0.5×LB) internalized lettuce leaf better (62 ± 5% and 59 ± 7%, respectively) compared to bacteria grown in LB (15 ± 7%). Growth under non-aerated conditions also enhanced STm internalization compared to growth under aerated conditions. Growth temperature of 25 and 37°C did not affect STm internalization, however, growth at 42°C, significantly augmented leaf internalization. Since, the tested growth conditions represent moderate stresses, we further investigated the involvement of five universal-stress genes in STm leaf internalization following growth in LBNS medium. Knockout mutations in ydaA, yecG, ybdQ, and uspAB, but not in ynaF, significantly reduced STm internalization compared to the wild-type (wt) strain, without affecting bacterial attachment and motility. Transduction of the mutations back to the parent strain confirmed the linkage between the mutations and the internalization phenotype. These findings support a specific role of the universal-stress genes in leaf internalization. The present study highlights the complexity of bacterial internalization process and may provide partial explanation for the variable, sometimes-contrasting results reported in the literature regarding stomatal internalization by HPOP. Characterization of the regulatory networks that mediate the involvement of usp genes and the tested growth factors in STm internalization should contribute to our understanding of human pathogens-plant interactions.
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Affiliation(s)
- Yulia Kroupitski
- Microbial Food-Safety Research Unit, Department of Food Science, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Rachel Gollop
- Microbial Food-Safety Research Unit, Department of Food Science, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Eduard Belausov
- Confocal Microscopy Unit, Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Riky Pinto
- Microbial Food-Safety Research Unit, Department of Food Science, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
| | - Shlomo Sela Saldinger
- Microbial Food-Safety Research Unit, Department of Food Science, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel
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Be’er A, Ariel G. A statistical physics view of swarming bacteria. MOVEMENT ECOLOGY 2019; 7:9. [PMID: 30923619 PMCID: PMC6419441 DOI: 10.1186/s40462-019-0153-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/18/2019] [Indexed: 05/18/2023]
Abstract
Bacterial swarming is a collective mode of motion in which cells migrate rapidly over surfaces, forming dynamic patterns of whirls and jets. This review presents a physical point of view of swarming bacteria, with an emphasis on the statistical properties of the swarm dynamics as observed in experiments. The basic physical principles underlying the swarm and their relation to contemporary theories of collective motion and active matter are reviewed and discussed in the context of the biological properties of swarming cells. We suggest a paradigm according to which bacteria have optimized some of their physical properties as a strategy for rapid surface translocation. In other words, cells take advantage of favorable physics, enabling efficient expansion that enhances survival under harsh conditions.
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Affiliation(s)
- Avraham Be’er
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990 Midreshet Ben-Gurion, Israel
- Department of Physics, Ben-Gurion University of the Negev, 84105 Beer Sheva, Israel
| | - Gil Ariel
- Department of Mathematics, Bar-Ilan University, 52000 Ramat Gan, Israel
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A Family of Small Intrinsically Disordered Proteins Involved in Flagellum-Dependent Motility in Salmonella enterica. J Bacteriol 2018; 201:JB.00415-18. [PMID: 30373755 DOI: 10.1128/jb.00415-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/21/2018] [Indexed: 02/08/2023] Open
Abstract
By screening a collection of Salmonella mutants deleted for genes encoding small proteins of ≤60 amino acids, we identified three paralogous small genes (ymdF, STM14_1829, and yciG) required for wild-type flagellum-dependent swimming and swarming motility. The ymdF, STM14_1829, and yciG genes encode small proteins of 55, 60, and 60 amino acid residues, respectively. A bioinformatics analysis predicted that these small proteins are intrinsically disordered proteins, and circular dichroism analysis of purified recombinant proteins confirmed that all three proteins are unstructured in solution. A mutant deleted for STM14_1829 showed the most severe motility defect, indicating that among the three paralogs, STM14_1829 is a key protein required for wild-type motility. We determined that relative to the wild type, the expression of the flagellin protein FliC is lower in the ΔSTM14_1829 mutant due to the downregulation of the flhDC operon encoding the FlhDC master regulator. By comparing the gene expression profiles between the wild-type and ΔSTM14_1829 strains via RNA sequencing, we found that the gene encoding the response regulator PhoP is upregulated in the ΔSTM14_1829 mutant, suggesting the indirect repression of the flhDC operon by the activated PhoP. Homologs of STM14_1829 are conserved in a wide range of bacteria, including Escherichia coli and Pseudomonas aeruginosa We showed that the inactivation of STM14_1829 homologs in E. coli and P. aeruginosa also alters motility, suggesting that this family of small intrinsically disordered proteins may play a role in the cellular pathway(s) that affects motility.IMPORTANCE This study reports the identification of a novel family of small intrinsically disordered proteins that are conserved in a wide range of flagellated and nonflagellated bacteria. Although this study identifies the role of these small proteins in the scope of flagellum-dependent motility in Salmonella, they likely play larger roles in a more conserved cellular pathway(s) that indirectly affects flagellum expression in the case of motile bacteria. Small intrinsically disordered proteins have not been well characterized in prokaryotes, and the results of our study provide a basis for their detailed functional characterization.
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Patteson AE, Gopinath A, Arratia PE. The propagation of active-passive interfaces in bacterial swarms. Nat Commun 2018; 9:5373. [PMID: 30560867 PMCID: PMC6299137 DOI: 10.1038/s41467-018-07781-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/20/2018] [Indexed: 11/08/2022] Open
Abstract
Propagating interfaces are ubiquitous in nature, underlying instabilities and pattern formation in biology and material science. Physical principles governing interface growth are well understood in passive settings; however, our understanding of interfaces in active systems is still in its infancy. Here, we study the evolution of an active-passive interface using a model active matter system, bacterial swarms. We use ultra-violet light exposure to create compact domains of passive bacteria within Serratia marcescens swarms, thereby creating interfaces separating motile and immotile cells. Post-exposure, the boundary re-shapes and erodes due to self-emergent collective flows. We demonstrate that the active-passive boundary acts as a diffuse interface with mechanical properties set by the flow. Intriguingly, interfacial velocity couples to local swarm speed and interface curvature, raising the possibility that an active analogue to classic Gibbs-Thomson-Stefan conditions may control this boundary propagation.
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Affiliation(s)
- Alison E Patteson
- Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Physics Department, Syracuse University, Syracuse, NY, 13244, USA.
| | - Arvind Gopinath
- Department of Bioengineering, University of California, Merced, CA, 95340, USA
- Health Sciences Research Institute, University of California, Merced, CA, 95340, USA
| | - Paulo E Arratia
- Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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31
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Partridge JD, Ariel G, Schvartz O, Harshey RM, Be'er A. The 3D architecture of a bacterial swarm has implications for antibiotic tolerance. Sci Rep 2018; 8:15823. [PMID: 30361680 PMCID: PMC6202419 DOI: 10.1038/s41598-018-34192-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 10/11/2018] [Indexed: 12/04/2022] Open
Abstract
Swarming bacteria are an example of a complex, active biological system, where high cell density and super-diffusive cell mobility confer survival advantages to the group as a whole. Previous studies on the dynamics of the swarm have been limited to easily observable regions at the advancing edge of the swarm where cells are restricted to a plane. In this study, using defocused epifluorescence video imaging, we have tracked the motion of fluorescently labeled individuals within the interior of a densely packed three-dimensional (3D) region of a swarm. Our analysis reveals a novel 3D architecture, where bacteria are constrained by inter-particle interactions, sandwiched between two distinct boundary conditions. We find that secreted biosurfactants keep bacteria away from the swarm-air upper boundary, and added antibiotics at the lower swarm-surface boundary lead to their migration away from this boundary. Formation of the antibiotic-avoidance zone is dependent on a functional chemotaxis signaling system, in the absence of which the swarm loses its high tolerance to the antibiotics.
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Affiliation(s)
- Jonathan D Partridge
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, 78712, USA
| | - Gil Ariel
- Department of Mathematics, Bar-Ilan University, Ramat Gan, 52000, Israel
| | - Orly Schvartz
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Midreshet Ben-Gurion, Israel
| | - Rasika M Harshey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, 78712, USA.
| | - Avraham Be'er
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Midreshet Ben-Gurion, Israel. .,Department of Physics, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.
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32
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Biofilm formation and potential virulence factors of Salmonella strains isolated from ready-to-eat shrimps. PLoS One 2018; 13:e0204345. [PMID: 30235341 PMCID: PMC6147607 DOI: 10.1371/journal.pone.0204345] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 09/06/2018] [Indexed: 11/21/2022] Open
Abstract
Salmonella species is an important foodborne pathogen with the non-typhoidal serovars such as Enteritidis and Typhimurium as the most predominant strains. This study examines the biofilm formation, phenotypic virulence factors and cell surface characteristics of Salmonella strains from ready-to-eat shrimps. The ready-to-eat shrimps were obtained from open markets between November 2016 and October 2017 in Edo and Delta States, Nigeria. The occurrence of Salmonella strains in this study was 210/1440 (14.58%) of the ready-to-eat shrimp’s samples. The identified strains comprise of Salmonella Enteritidis 11, Salmonella Typhimurium 14 and other Salmonella spp. 20. The 45 identified Salmonella strains revealed the following virulence properties: swimming and swarming motility 45(100%); S-layer 39(86.67%); haemolytic activity 40(88.89%); lipase activity 43(95.56%); protease activity 43(95.56%); gelatinase production 43(95.56%); and DNA degrading activity 41(91.11%). The variation in the formation of biofilm-based on the diversity of Salmonella species was observed with higher percentage of Salmonella Typhimurium strains as strong biofilms producers under different environmental conditions. For surface hydrophobicity using bacterial adherence to hydrocarbons, 25(55.56%) were hydrophilic while 20(44.44%) were moderately hydrophobic from the 45 Salmonella isolates. Using salting aggregation test for surface hydrophobicity, all selected isolates 45(100%) was hydrophilic. Autoaggregation index for the 12 selected Salmonella isolates ranged from 15.2–47.2%, while the autoaggragation index for the 12 selected test bacteria ranged from 26.2–71.3%. Coaggragation between the 12 selected test bacteria and 12 Salmonella isolates ranged from 12.5–81.0%. The occurrence of pathogenic species of Salmonella from ready-to-eat shrimps could be detrimental to the consumers. Findings on the physiological conditions of biofilms formed by the foodborne pathogenic Salmonella and the cell surface characteristics therein are crucial for the advancement of methods for controlling Salmonella from ready-to-eat foods.
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Ford KM, Antani JD, Nagarajan A, Johnson MM, Lele PP. Switching and Torque Generation in Swarming E. coli. Front Microbiol 2018; 9:2197. [PMID: 30279682 PMCID: PMC6153309 DOI: 10.3389/fmicb.2018.02197] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/28/2018] [Indexed: 12/14/2022] Open
Abstract
Escherichia coli swarm on semi-solid surfaces with the aid of flagella. It has been hypothesized that swarmer cells overcome the increased viscous drag near surfaces by developing higher flagellar thrust and by promoting surface wetness with the aid of a flagellar switch. The switch enables reversals between clockwise (CW) and counterclockwise (CCW) directions of rotation of the flagellar motor. Here, we measured the behavior of flagellar motors in swarmer cells. Results indicated that although the torque was similar to that in planktonic cells, the tendency to rotate CCW was higher in swarmer cells. This suggested that swarmers likely have a smaller pool of phosphorylated CheY. Results further indicated that the upregulation of the flagellin gene was not critical for flagellar thrust or swarming. Consistent with earlier reports, moisture added to the swarm surface restored swarming in a CCW-only mutant, but not in a FliG mutant that rotated motors CW-only (FliGCW). Fluorescence assays revealed that FliGCW cells grown on agar surfaces carried fewer flagella than planktonic FliGCW cells. The surface-dependent reduction in flagella correlated with a reduction in the number of putative flagellar preassemblies. These results hint toward a possibility that the conformational dynamics of switch proteins play a role in the proper assembly of flagellar complexes and flagellar export, thereby aiding bacterial swarming.
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Affiliation(s)
- Katie M Ford
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
| | - Jyot D Antani
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
| | - Aravindh Nagarajan
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
| | - Madeline M Johnson
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
| | - Pushkar P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
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Segev-Zarko LA, Kapach G, Josten M, Klug YA, Sahl HG, Shai Y. Deficient Lipid A Remodeling by the arnB Gene Promotes Biofilm Formation in Antimicrobial Peptide Susceptible Pseudomonas aeruginosa. Biochemistry 2018. [PMID: 29518324 DOI: 10.1021/acs.biochem.8b00149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Multidrug resistant bacteria possess various mechanisms that can sense environmental stresses such as antibiotics and antimicrobial peptides and rapidly respond to defend themselves. Two known defense strategies are biofilm formation and lipopolysaccharide (LPS) modification. Though LPS modifications are observed in biofilm-embedded bacteria, their effect on biofilm formation is unknown. Using biochemical and biophysical methods coupled with confocal microscopy, atomic force microscopy, and transmission electron microscopy, we show that biofilm formation is promoted in a Pseudomonas aeruginosa PAO1 strain with a loss of function mutation in the arnB gene. This loss of function prevents the addition of the positively charged sugar 4-amino-4-deoxy-l-arabinose to lipid A of LPS under restrictive magnesium conditions. The data reveal that the arnB mutant, which is susceptible to antimicrobial peptides, forms a biofilm that is more robust than that of the wild type. This is in line with the observations that the arnB mutant exhibits outer surface properties such as hydrophobicity and net negative charge that promote the formation of biofilms. Moreover, when grown under Mg2+ limitation, both the wild type and the arnB mutant exhibited a reduction in the level of membrane-bound polysaccharides. The data suggest that the loss of polysaccharides exposes the membrane and alters its biophysical properties, which in turn leads to more biofilm formation. In summary, we show for the first time that blocking a specific lipid A modification promotes biofilm formation, suggesting a trade-off between LPS remodeling and resistance mechanisms of biofilm formation.
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Affiliation(s)
- Li-Av Segev-Zarko
- Department of Biomolecular Sciences , The Weizmann Institute of Science , Rehovot , Israel
| | - Gal Kapach
- Department of Biomolecular Sciences , The Weizmann Institute of Science , Rehovot , Israel
| | - Michaele Josten
- Institute of Medical Microbiology, Immunology and Parasitology , University of Bonn , Bonn , Germany
| | - Yoel Alexander Klug
- Department of Biomolecular Sciences , The Weizmann Institute of Science , Rehovot , Israel
| | - Hans-Georg Sahl
- Institute of Medical Microbiology, Immunology and Parasitology , University of Bonn , Bonn , Germany
| | - Yechiel Shai
- Department of Biomolecular Sciences , The Weizmann Institute of Science , Rehovot , Israel
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35
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Ng IS, Hsueh CC, Chen BY. Electron transport phenomena of electroactive bacteria in microbial fuel cells: a review of Proteus hauseri. BIORESOUR BIOPROCESS 2017. [DOI: 10.1186/s40643-017-0183-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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36
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Multidrug-Resistant Salmonella enterica Serovar Typhimurium Isolates Are Resistant to Antibiotics That Influence Their Swimming and Swarming Motility. mSphere 2017; 2:mSphere00306-17. [PMID: 29104932 PMCID: PMC5663980 DOI: 10.1128/msphere.00306-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/02/2017] [Indexed: 12/31/2022] Open
Abstract
Salmonella is one of the most common causes of bacterial foodborne infections in the United States, and the Centers for Disease Control consider multidrug-resistant (MDR) Salmonella a “Serious Threat Level pathogen.” Because MDR Salmonella can lead to more severe disease in patients than that caused by antibiotic-sensitive strains, it is important to identify the role that antibiotics may play in enhancing Salmonella virulence. The current study examined several MDR Salmonella isolates and determined the effect that various antibiotics had on Salmonella motility, an important virulence-associated factor. While most antibiotics had a neutral or negative effect on motility, we found that kanamycin actually enhanced MDR Salmonella swarming in some isolates. Subsequent experiments showed this phenotype as being dependent on a combination of several different genetic factors. Understanding the influence that antibiotics have on MDR Salmonella motility is critical to the proper selection and prudent use of antibiotics for efficacious treatment while minimizing potential collateral consequences. Motile bacteria employ one or more methods for movement, including darting, gliding, sliding, swarming, swimming, and twitching. Multidrug-resistant (MDR) Salmonella carries acquired genes that provide resistance to specific antibiotics, and the goal of our study was to determine how antibiotics influence swimming and swarming in such resistant Salmonella isolates. Differences in motility were examined for six MDR Salmonella enterica serovar Typhimurium isolates grown on swimming and swarming media containing subinhibitory concentrations of chloramphenicol, kanamycin, streptomycin, or tetracycline. Chloramphenicol and tetracycline reduced both swimming and swarming, though the effect was more pronounced for swimming than for swarming at the same antibiotic and concentration. Swimming was limited by kanamycin and streptomycin, but these antibiotics had much less influence on decreasing swarming. Interestingly, kanamycin significantly increased swarming in one of the isolates. Removal of the aphA1 kanamycin resistance gene and complementation with either the aphA1 or aphA2 kanamycin resistance gene revealed that aphA1, along with an unidentified Salmonella genetic factor, was required for the kanamycin-enhanced swarming phenotype. Screening of 25 additional kanamycin-resistant isolates identified two that also had significantly increased swarming motility in the presence of kanamycin. This study demonstrated that many variables influence how antibiotics impact swimming and swarming motility in MDR S. Typhimurium, including antibiotic type, antibiotic concentration, antibiotic resistance gene, and isolate-specific factors. Identifying these isolate-specific factors and how they interact will be important to better understand how antibiotics influence MDR Salmonella motility. IMPORTANCESalmonella is one of the most common causes of bacterial foodborne infections in the United States, and the Centers for Disease Control consider multidrug-resistant (MDR) Salmonella a “Serious Threat Level pathogen.” Because MDR Salmonella can lead to more severe disease in patients than that caused by antibiotic-sensitive strains, it is important to identify the role that antibiotics may play in enhancing Salmonella virulence. The current study examined several MDR Salmonella isolates and determined the effect that various antibiotics had on Salmonella motility, an important virulence-associated factor. While most antibiotics had a neutral or negative effect on motility, we found that kanamycin actually enhanced MDR Salmonella swarming in some isolates. Subsequent experiments showed this phenotype as being dependent on a combination of several different genetic factors. Understanding the influence that antibiotics have on MDR Salmonella motility is critical to the proper selection and prudent use of antibiotics for efficacious treatment while minimizing potential collateral consequences.
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Anti-biofilm effects of anthranilate on a broad range of bacteria. Sci Rep 2017; 7:8604. [PMID: 28819217 PMCID: PMC5561115 DOI: 10.1038/s41598-017-06540-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 06/14/2017] [Indexed: 01/16/2023] Open
Abstract
Anthranilate, one of tryptophan degradation products has been reported to interfere with biofilm formation by Pseudomonas aeruginosa. Here, we investigated the effects of anthranilate on biofilm formation by various bacteria and the mechanisms responsible. Anthranilate commonly inhibited biofilm formation by P. aeruginosa, Vibrio vulnificus, Bacillus subtilis, Salmonella enterica serovar Typhimurium, and Staphylococcus aureus, and disrupted biofilms preformed by these bacteria. Because anthranilate reduced intracellular c-di-GMP and enhanced swimming and swarming motilities in P. aeruginosa, V. vulnificus, B. subtilis, and S. enterica, it is likely that anthranilate disrupts biofilms by inducing the dispersion of these bacteria. On the other hand, in S. aureus, a non-flagellate bacterium that has no c-di-GMP signaling, anthranilate probably inhibits biofilm formation by reducing slime production. These results suggest that anthranilate has multiple ways for biofilm inhibition. Furthermore, because of its good biofilm inhibitory effects and lack of cytotoxicity to human cells even at high concentration, anthranilate appears to be a promising agent for inhibiting biofilm formation by a broad range of bacteria.
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Irazoki O, Campoy S, Barbé J. The Transient Multidrug Resistance Phenotype of Salmonella enterica Swarming Cells Is Abolished by Sub-inhibitory Concentrations of Antimicrobial Compounds. Front Microbiol 2017; 8:1360. [PMID: 28769915 PMCID: PMC5515874 DOI: 10.3389/fmicb.2017.01360] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/04/2017] [Indexed: 12/12/2022] Open
Abstract
Swarming motility is the rapid and coordinated multicellular migration of bacteria across a moist surface. During swarming, bacterial cells exhibit increased resistance to multiple antibiotics, a phenomenon described as adaptive or transient resistance. In this study, we demonstrate that sub-inhibitory concentrations of cefotaxime, ciprofloxacin, trimethoprim, or chloramphenicol, but not that of amikacin, colistin, kanamycin or tetracycline, impair Salmonella enterica swarming. Chloramphenicol-treated S. enterica cells exhibited a clear decrease in their flagellar content, while treatment with other antibiotics that reduced swarming (cefotaxime, ciprofloxacin, and trimethoprim) inhibited polar chemoreceptor array assembly. Moreover, the increased resistance phenotype acquired by swarming cells was abolished by the presence of these antimicrobials. The same occurred in cells treated with these antimicrobial agents in combination with others that had no effect on swarming motility. Our results reveal the potential of inhibiting swarming ability to enhance the therapeutic effectiveness of antimicrobial agents.
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Affiliation(s)
- Oihane Irazoki
- Departament de Genètica i de Microbiologia, Universitat Autònoma de BarcelonaBarcelona, Spain
| | - Susana Campoy
- Departament de Genètica i de Microbiologia, Universitat Autònoma de BarcelonaBarcelona, Spain
| | - Jordi Barbé
- Departament de Genètica i de Microbiologia, Universitat Autònoma de BarcelonaBarcelona, Spain
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Zhai H, Li Y, Sanchez S, Kearns DB, Wu Y. Noncontact Cohesive Swimming of Bacteria in Two-Dimensional Liquid Films. PHYSICAL REVIEW LETTERS 2017; 119:018101. [PMID: 28731758 PMCID: PMC5960272 DOI: 10.1103/physrevlett.119.018101] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Indexed: 05/29/2023]
Abstract
Bacterial swimming in confined two-dimensional environments is ubiquitous in nature and in clinical settings. Characterizing individual interactions between swimming bacteria in 2D confinement will help to understand diverse microbial processes, such as bacterial swarming and biofilm formation. Here we report a novel motion pattern displayed by flagellated bacteria in 2D confinement: When two nearby cells align their moving directions, they tend to engage in cohesive swimming without direct cell body contact, as a result of hydrodynamic interaction but not flagellar intertwining. We further found that cells in cohesive swimming move with higher directional persistence, which can increase the effective diffusivity of cells by ∼3 times as predicted by computational modeling. As a conserved behavior for peritrichously flagellated bacteria, cohesive swimming in 2D confinement may be key to collective motion and self-organization in bacterial swarms; it may also promote bacterial dispersal in unsaturated soils and in interstitial space during infections.
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Affiliation(s)
- He Zhai
- Department of Physics, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, P.R. China
| | - Ye Li
- Department of Physics, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, P.R. China
| | - Sandra Sanchez
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
| | - Daniel B. Kearns
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
| | - Yilin Wu
- Department of Physics, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, P.R. China
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Patterns of virulence factor expression and antimicrobial resistance in Achromobacter xylosoxidans and Achromobacter ruhlandii isolates from patients with cystic fibrosis. Epidemiol Infect 2016; 145:600-606. [PMID: 27873565 DOI: 10.1017/s0950268816002624] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Achromobacter spp. are opportunistic pathogens increasingly recovered from adult patients with cystic fibrosis (CF). We report the characterization of 122 Achromobacter spp. isolates recovered from 39 CF patients by multilocus sequence typing, virulence traits, and susceptibility to antimicrobials. Two species, A. xylosoxidans (77%) and A. ruhlandii (23%) were identified. All isolates showed a similar biofilm formation ability, and a positive swimming phenotype. By contrast, 4·3% and 44·4% of A. xylosoxidans and A. ruhlandii, respectively, exhibited a negative swarming phenotype, making the swimming and swarming abilities of A. xylosoxidans significantly higher than those of A. ruhlandii. A. xylosoxidans isolates from an outbreak clone also exhibited significantly higher motility. Both species were generally susceptible to ceftazidime, ciprofloxacin, imipenem and trimethoprim/sulphamethoxazole and there was no significant difference in susceptibility between isolates from chronic or sporadic infection. However, A. xylosoxidans isolates from chronic and sporadic cases were significantly more resistant to imipenem and ceftazidime than isolates of the outbreak clone.
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Irazoki O, Aranda J, Zimmermann T, Campoy S, Barbé J. Molecular Interaction and Cellular Location of RecA and CheW Proteins in Salmonella enterica during SOS Response and Their Implication in Swarming. Front Microbiol 2016; 7:1560. [PMID: 27766091 PMCID: PMC5052270 DOI: 10.3389/fmicb.2016.01560] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/20/2016] [Indexed: 12/21/2022] Open
Abstract
In addition to its role in DNA damage repair and recombination, the RecA protein, through its interaction with CheW, is involved in swarming motility, a form of flagella-dependent movement across surfaces. In order to better understand how SOS response modulates swarming, in this work the location of RecA and CheW proteins within the swarming cells has been studied by using super-resolution microscopy. Further, and after in silico docking studies, the specific RecA and CheW regions associated with the RecA-CheW interaction have also been confirmed by site-directed mutagenesis and immunoprecipitation techniques. Our results point out that the CheW distribution changes, from the cell poles to foci distributed in a helical pattern along the cell axis when SOS response is activated or RecA protein is overexpressed. In this situation, the CheW presents the same subcellular location as that of RecA, pointing out that the previously described RecA storage structures may be modulators of swarming motility. Data reported herein not only confirmed that the RecA-CheW pair is essential for swarming motility but it is directly involved in the CheW distribution change associated to SOS response activation. A model explaining not only the mechanism by which DNA damage modulates swarming but also how both the lack and the excess of RecA protein impair this motility is proposed.
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Affiliation(s)
- Oihane Irazoki
- Department de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Cerdanyola del Vallès, Spain
| | - Jesús Aranda
- Department de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Cerdanyola del Vallès, Spain
| | - Timo Zimmermann
- Advanced Light Microscopy Unit, Center for Genomic Regulation Barcelona, Spain
| | - Susana Campoy
- Department de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Cerdanyola del Vallès, Spain
| | - Jordi Barbé
- Department de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Cerdanyola del Vallès, Spain
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García-Heredia A, García S, Merino-Mascorro JÁ, Feng P, Heredia N. Natural plant products inhibits growth and alters the swarming motility, biofilm formation, and expression of virulence genes in enteroaggregative and enterohemorrhagic Escherichia coli. Food Microbiol 2016; 59:124-32. [DOI: 10.1016/j.fm.2016.06.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 05/30/2016] [Accepted: 06/02/2016] [Indexed: 12/20/2022]
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Wu Y, Park KC, Choi BG, Park JH, Yoon KS. The Antibiofilm Effect ofGinkgo bilobaExtract AgainstSalmonellaandListeriaIsolates from Poultry. Foodborne Pathog Dis 2016; 13:229-38. [DOI: 10.1089/fpd.2015.2072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Yan Wu
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Keun Cheol Park
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Beom Geun Choi
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Jin Hwa Park
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
| | - Ki Sun Yoon
- Department of Food and Nutrition, College of Human Ecology, Kyung Hee University, Seoul, Republic of Korea
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SOS System Induction Inhibits the Assembly of Chemoreceptor Signaling Clusters in Salmonella enterica. PLoS One 2016; 11:e0146685. [PMID: 26784887 PMCID: PMC4718596 DOI: 10.1371/journal.pone.0146685] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/21/2015] [Indexed: 01/08/2023] Open
Abstract
Swarming, a flagellar-driven multicellular form of motility, is associated with bacterial virulence and increased antibiotic resistance. In this work we demonstrate that activation of the SOS response reversibly inhibits swarming motility by preventing the assembly of chemoreceptor-signaling polar arrays. We also show that an increase in the concentration of the RecA protein, generated by SOS system activation, rather than another function of this genetic network impairs chemoreceptor polar cluster formation. Our data provide evidence that the molecular balance between RecA and CheW proteins is crucial to allow polar cluster formation in Salmonella enterica cells. Thus, activation of the SOS response by the presence of a DNA-injuring compound increases the RecA concentration, thereby disturbing the equilibrium between RecA and CheW and resulting in the cessation of swarming. Nevertheless, when the DNA-damage decreases and the SOS response is no longer activated, basal RecA levels and thus polar cluster assembly are reestablished. These results clearly show that bacterial populations moving over surfaces make use of specific mechanisms to avoid contact with DNA-damaging compounds.
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Lu S, Liu F, Xing B, Yeow EKL. Nontoxic colloidal particles impede antibiotic resistance of swarming bacteria by disrupting collective motion and speed. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:062706. [PMID: 26764726 DOI: 10.1103/physreve.92.062706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Indexed: 06/05/2023]
Abstract
A monolayer of swarming B. subtilis on semisolid agar is shown to display enhanced resistance against antibacterial drugs due to their collective behavior and motility. The dynamics of swarming motion, visualized in real time using time-lapse microscopy, prevents the bacteria from prolonged exposure to lethal drug concentrations. The elevated drug resistance is significantly reduced when the collective motion of bacteria is judiciously disrupted using nontoxic polystyrene colloidal particles immobilized on the agar surface. The colloidal particles block and hinder the motion of the cells, and force large swarming rafts to break up into smaller packs in order to maneuver across narrow spaces between densely packed particles. In this manner, cohesive rafts rapidly lose their collectivity, speed, and group dynamics, and the cells become vulnerable to the drugs. The antibiotic resistance capability of swarming B. subtilis is experimentally observed to be negatively correlated with the number density of colloidal particles on the engineered surface. This relationship is further tested using an improved self-propelled particle model that takes into account interparticle alignment and hard-core repulsion. This work has pertinent implications on the design of optimal methods to treat drug resistant bacteria commonly found in swarming colonies.
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Affiliation(s)
- Shengtao Lu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore
| | - Fang Liu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore
| | - Bengang Xing
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore
| | - Edwin K L Yeow
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore
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Hossain MA, Lee SJ, Park JY, Reza MA, Kim TH, Lee KJ, Suh JW, Park SC. Modulation of quorum sensing-controlled virulence factors by Nymphaea tetragona (water lily) extract. JOURNAL OF ETHNOPHARMACOLOGY 2015; 174:482-491. [PMID: 26325430 DOI: 10.1016/j.jep.2015.08.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 07/16/2015] [Accepted: 08/27/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Nymphaea tetragona is a widely distributed ornamental species with ethnomedicinal uses in the treatment of diarrhea, dysentery, eruptive fevers, and infections. The anti-infectious activities of this herb have already been assessed to clarify its traditional use as a medicine. AIM OF STUDY In this study, we aimed to verify the inhibitory effects of N. tetragona 50% methanol extract (NTME) on quorum sensing (QS)-controlled virulence factors of bacteria since QS and its virulence factors are novel targets for antimicrobial therapy. MATERIALS AND METHODS The antibacterial activity of this extract was evaluated against Chromobacterium violaceum and Pseudomonas aeruginosa. The inhibition of the violacein pigment of C. violaceum by NTME was determined qualitative and quantitative using standard methods. The effects of NTME on swarming motility, biofilm viability, pyocyanin production, and LasA protease activity were evaluated using P. aeruginosa. Finally, the in vitro and in vivo cytotoxicity of NTME were verified by MTT assay and oral administration to rats, respectively. RESULTS The extract had concentration-dependent antibacterial activity against gram-negative bacteria. NTME at 1/2× minimum inhibitory concentration (MIC), 1× MIC and 2× MIC significantly lowered the levels of violacein of C. violaceum compared to that of the control. The swarming motility of P. aeruginosa was inhibited by ≥70% by treatment with 1/2× MIC of NTME. There were remarkable reductions in pyocyanin production and LasA protease activity in the overnight culture supernatant of P. aeruginosa supplemented with NTME when compared with that of the untreated control. The confocal micrographs of 24h biofilms of P. aeruginosa exposed to NTME exhibited a lower number of live cells than the control. No toxic effect was observed in in vitro and in vivo cytotoxicity assays of NTME. CONCLUSIONS NTME was demonstrated to have significant concentration-dependent inhibitory effects on quorum sensing-mediated virulence factors of bacteria with non-toxic properties, and could thus be a prospective quorum sensing inhibitor.
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Affiliation(s)
- Md Akil Hossain
- College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea.
| | - Seung-Jin Lee
- College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea.
| | - Ji-Yong Park
- College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea; Institute of Clean Bio, Daejeon 301-212, South Korea.
| | - Md Ahsanur Reza
- Faculty of Animal Science and Veterinary Medicine, Patuakhali Science and Technology University (Outer Campus), Babugonj, Barisal 8210, Bangladesh.
| | - Tae-Hwan Kim
- College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea.
| | - Ki-Ja Lee
- College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea.
| | - Joo-Won Suh
- Center for Nutraceutical and Pharmaceutical Materials, Division of Bioscience and Bioinformatics, Science campus, Myongji University, San 38-2, Namdong, Cheoin-Gu, Yongin, Gyeonggi 449-728, South Korea.
| | - Seung-Chun Park
- College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, South Korea.
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Ariel G, Rabani A, Benisty S, Partridge JD, Harshey RM, Be'er A. Swarming bacteria migrate by Lévy Walk. Nat Commun 2015; 6:8396. [PMID: 26403719 PMCID: PMC4598630 DOI: 10.1038/ncomms9396] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 08/19/2015] [Indexed: 12/24/2022] Open
Abstract
Individual swimming bacteria are known to bias their random trajectories in search of food and to optimize survival. The motion of bacteria within a swarm, wherein they migrate as a collective group over a solid surface, is fundamentally different as typical bacterial swarms show large-scale swirling and streaming motions involving millions to billions of cells. Here by tracking trajectories of fluorescently labelled individuals within such dense swarms, we find that the bacteria are performing super-diffusion, consistent with Lévy walks. Lévy walks are characterized by trajectories that have straight stretches for extended lengths whose variance is infinite. The evidence of super-diffusion consistent with Lévy walks in bacteria suggests that this strategy may have evolved considerably earlier than previously thought.
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Affiliation(s)
- Gil Ariel
- Department of Mathematics, Bar-Ilan University, Ramat Gan 52000, Israel
| | - Amit Rabani
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Midreshet Ben-Gurion, Israel
| | - Sivan Benisty
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Midreshet Ben-Gurion, Israel
| | - Jonathan D. Partridge
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, USA
| | - Rasika M. Harshey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, USA
| | - Avraham Be'er
- Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Midreshet Ben-Gurion, Israel
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48
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Harshey RM, Partridge JD. Shelter in a Swarm. J Mol Biol 2015; 427:3683-94. [PMID: 26277623 DOI: 10.1016/j.jmb.2015.07.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/29/2015] [Accepted: 07/31/2015] [Indexed: 01/04/2023]
Abstract
Flagella propel bacteria during both swimming and swarming, dispersing them widely. However, while swimming bacteria use chemotaxis to find nutrients and avoid toxic environments, swarming bacteria appear to suppress chemotaxis and to use the dynamics of their collective motion to continuously expand and acquire new territory, barrel through lethal chemicals in their path, carry along bacterial and fungal cargo that assists in exploration of new niches, and engage in group warfare for niche dominance. Here, we focus on two aspects of swarming, which, if understood, hold the promise of revealing new insights into microbial signaling and behavior, with ramifications beyond bacterial swarming. These are as follows: how bacteria sense they are on a surface and turn on programs that promote movement and how they override scarcity and adversity as dense packs.
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Affiliation(s)
- Rasika M Harshey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
| | - Jonathan D Partridge
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
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Density-dependent adaptive resistance allows swimming bacteria to colonize an antibiotic gradient. ISME JOURNAL 2015; 10:30-8. [PMID: 26140531 DOI: 10.1038/ismej.2015.107] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 04/09/2015] [Accepted: 05/19/2015] [Indexed: 11/08/2022]
Abstract
During antibiotic treatment, antibiotic concentration gradients develop. Little is know regarding the effects of antibiotic gradients on populations of nonresistant bacteria. Using a microfluidic device, we show that high-density motile Escherichia coli populations composed of nonresistant bacteria can, unexpectedly, colonize environments where a lethal concentration of the antibiotic kanamycin is present. Colonizing bacteria establish an adaptively resistant population, which remains viable for over 24 h while exposed to the antibiotic. Quantitative analysis of multiple colonization events shows that collectively swimming bacteria need to exceed a critical population density in order to successfully colonize the antibiotic landscape. After colonization, bacteria are not dormant but show both growth and swimming motility under antibiotic stress. Our results highlight the importance of motility and population density in facilitating adaptive resistance, and indicate that adaptive resistance may be a first step to the emergence of genetically encoded resistance in landscapes of antibiotic gradients.
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50
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Sterilization of polydimethylsiloxane surface with Chinese herb extract: a new antibiotic mechanism of chlorogenic acid. Sci Rep 2015; 5:10464. [PMID: 25993914 PMCID: PMC4650805 DOI: 10.1038/srep10464] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 04/15/2015] [Indexed: 11/08/2022] Open
Abstract
Coating of polydimethylsiloxane (PDMS) surface with a traditional Chinese herb extract chlorogenic acid (CA) solves the contemporary problem of sterilization of PDMS surface. The E. coli grows slower and has a higher death rate on the CA-coated PDMS surfaces. A smoother morphology of these E. coli cell wall is observed by atomic force microscopy (AFM). Unlike the reported mechanism, where CA inhibits bacterial growth by damaging the cell membrane in the bulk solution, we find the CA-coated PDMS surface also decreases the stiffness of the cell wall. A decrease in the Young's modulus of the cell wall from 3 to 0.8 MPa is reported. Unexpectedly, the CA effect on the swarming ability and the biofilm stability of the bacteria can be still observed, even after they have been removed from the CA environment, indicating a decrease in their resistance to antibiotics for a prolonged time. The CA-coated PDMS surface shows better antibiotic effect against three types of both Gram-positive and Gran-negative bacteria than the gentamicin-coated PDMS surface. Coating of CA on PDMS surface not only solves the problem of sterilization of PDMS surface, but also shines light on the application of Chinese traditional herbs in scientific research.
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