scholarly journals Role of the Mycobacterium marinum ESX-1 Secretion System in Sliding Motility and Biofilm Formation

2018 ◽  
Vol 9 ◽  
Author(s):  
Li-Yin Lai ◽  
Tzu-Lung Lin ◽  
Yi-Yin Chen ◽  
Pei-Fang Hsieh ◽  
Jin-Town Wang
Keyword(s):  
Biofilm Formation ◽  
Secretion System ◽  
Mycobacterium Marinum ◽  
Sliding Motility

scholarly journals Deletion of the rpoZ gene, encoding the ω subunit of RNA polymerase, results in pleiotropic surface-related phenotypes in Mycobacterium smegmatis

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1741-1750 ◽  
Author(s):  
Renjith Mathew ◽  
Raju Mukherjee ◽  
Radhakrishnan Balachandar ◽  
Dipankar Chatterji
Keyword(s):  
Rna Polymerase ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Physiological Role ◽  
Wild Type ◽  
Gene Encoding ◽  
Biofilm Growth ◽  
Mutant Bacterium ◽  
Sliding Motility

The ω subunit, the smallest subunit of bacterial RNA polymerase, is known to be involved in maintaining the conformation of the β′ subunit and aiding its recruitment to the rest of the core enzyme assembly in Escherichia coli. It has recently been shown in Mycobacterium smegmatis, by creating a deletion mutation of the rpoZ gene encoding ω, that the physiological role of the ω subunit also includes providing physical protection to β′. Interestingly, the mutant had altered colony morphology. This paper demonstrates that the mutant mycobacterium has pleiotropic phenotypes including reduced sliding motility and defective biofilm formation. Analysis of the spatial arrangement of biofilms by electron microscopy suggests that the altered phenotype of the mutant arises from a deficiency in generation of extracellular matrix. Complementation of the mutant strain with a copy of the wild-type rpoZ gene integrated in the bacterial chromosome restored both sliding motility and biofilm formation to the wild-type state, unequivocally proving the role of ω in the characteristics observed for the mutant bacterium. Analysis of the cell wall composition demonstrated that the mutant bacterium had an identical glycopeptidolipid profile to the wild-type, but failed to synthesize the short-chain mycolic acids characteristic of biofilm growth in M. smegmatis.

scholarly journals Type 1 Does the Two-Step: Type 1 Secretion Substrates with a Functional Periplasmic Intermediate

2018 ◽  
Vol 200 (18) ◽  
Author(s):  
T. Jarrod Smith ◽  
Holger Sondermann ◽  
George A. O'Toole
Keyword(s):  
Biofilm Formation ◽  
Cysteine Proteinase ◽  
Secretion System ◽  
Content Type ◽  
Distinct Subgroup ◽  
One Step ◽  
Step Type ◽  
Extracellular Environment

ABSTRACTBacteria have evolved several secretion strategies for polling and responding to environmental flux and insult. Of these, the type 1 secretion system (T1SS) is known to secrete an array of biologically diverse proteins—from small, <10-kDa bacteriocins to gigantic adhesins with a mass >1 MDa. For the last several decades, T1SSs have been characterized as a one-step translocation strategy whereby the secreted substrate is transported directly into the extracellular environment from the cytoplasm with no periplasmic intermediate. Recent phylogenetic, biochemical, and genetic evidences point to a distinct subgroup of T1SS machinery linked with a bacterial transglutaminase-like cysteine proteinase (BTLCP), which uses a two-step secretion mechanism. BTLCP-linked T1SSs transport a class of repeats-in-toxin (RTX) adhesins that are critical for biofilm formation. The prototype of this RTX adhesin group, LapA ofPseudomonas fluorescensPf0-1, uses a novel N-terminal retention module to anchor the adhesin at the cell surface as a secretion intermediate threaded through the outer membrane-localized TolC-like protein LapE. This secretion intermediate is posttranslationally cleaved by the BTLCP family LapG protein to release LapA from its cognate T1SS pore. Thus, the secretion of LapA and related RTX adhesins into the extracellular environment appears to be a T1SS-mediated two-step process that involves a periplasmic intermediate. In this review, we contrast the T1SS machinery and substrates of the BLTCP-linked two-step secretion process with those of the classical one-step T1SS to better understand the newly recognized and expanded role of this secretion machinery.

scholarly journals Exopolysaccharide protectsVibrio choleraefrom exogenous attacks by the type 6 secretion system

2018 ◽  
Vol 115 (31) ◽  
pp. 7997-8002 ◽  
Author(s):  
Jonida Toska ◽  
Brian T. Ho ◽  
John J. Mekalanos
Keyword(s):  
Biofilm Formation ◽  
Potential Role ◽  
Secretion System ◽  
Effector Proteins ◽  
Solid Surfaces ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Macromolecular Protein ◽  
Insight Into

The type 6 secretion system (T6SS) is a nanomachine used by many Gram-negative bacteria, includingVibrio cholerae, to deliver toxic effector proteins into adjacent eukaryotic and bacterial cells. Because the activity of the T6SS is dependent on direct contact between cells, its activity is limited to bacteria growing on solid surfaces or in biofilms.V. choleraecan produce an exopolysaccharide (EPS) matrix that plays a role in adhesion and biofilm formation. In this work, we investigated the effect of EPS production on T6SS activity between cells. We found that EPS produced byV. choleraecells functions as a unidirectional protective armor that blocks exogenous T6SS attacks without interfering with its own T6SS functionality. This EPS armor is effective against both same-species and heterologous attackers. Mutations modulating the level of EPS biosynthesis gene expression result in corresponding modulation inV. choleraeresistance to exogenous T6SS attack. These results provide insight into the potential role of extracellular biopolymers, including polysaccharides, capsules, and S-layers in protecting bacterial cells from attacks involving cell-associated macromolecular protein machines that cannot readily diffuse through these mechanical defenses.

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

scholarly journals The Potential Role of Bacteriophages in the Treatment of Recalcitrant Chronic Rhinosinusitis

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 675
Author(s):  
Saartje Uyttebroek ◽  
Jolien Onsea ◽  
Willem-Jan Metsemakers ◽  
Lieven Dupont ◽  
David Devolder ◽  
...  
Keyword(s):  
Chronic Rhinosinusitis ◽  
Biofilm Formation ◽  
Potential Role ◽  
Phage Therapy ◽  
Well Being ◽  
Treatment Alternative ◽  
Surgical Interventions ◽  
Social And Emotional ◽  
Promising Treatment

Chronic rhinosinusitis is a common condition affecting 5–12% of the general population worldwide. In a limited number of cases, the disease is recalcitrant to medical and surgical interventions, causing a major impact on physical, social and emotional well-being and increasing pressure on healthcare systems. Biofilm formation and dysbiosis caused by Staphylococcus aureus and Pseudomonas aeruginosa play a role in the pathogenesis of recalcitrant chronic rhinosinusitis. In these cases, a promising treatment alternative is the application of bacteriophages, which are viruses that infect and lyse bacteria. In this review, we appraise the evidence for the use of bacteriophages in the treatment of recalcitrant chronic rhinosinusitis. Additionally, (dis)advantages of bacteriophages and considerations for implementation of phage therapy in otorhinolaryngology practice will be discussed.

scholarly journals RND Efflux Systems Contribute to Resistance and Virulence of Aliarcobacter butzleri

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 823
Author(s):  
Cristiana Mateus ◽  
Ana Rita Nunes ◽  
Mónica Oleastro ◽  
Fernanda Domingues ◽  
Susana Ferreira
Keyword(s):  
Oxidative Stress ◽  
Human Serum ◽  
Ethidium Bromide ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Efflux Pumps ◽  
Bacterial Virulence ◽  
Relative Fitness ◽  
Mutant Strains

Aliarcobacter butzleri is an emergent enteropathogen that can be found in a range of environments. This bacterium presents a vast repertoire of efflux pumps, such as the ones belonging to the resistance nodulation cell division family, which may be associated with bacterial resistance, as well as virulence. Thus, this work aimed to evaluate the contribution of three RND efflux systems, AreABC, AreDEF and AreGHI, in the resistance and virulence of A. butzleri. Mutant strains were constructed by inactivation of the gene that encodes the inner membrane protein of these systems. The bacterial resistance profile of parental and mutant strains to several antimicrobials was assessed, as was the intracellular accumulation of the ethidium bromide dye. Regarding bacterial virulence, the role of these three efflux pumps on growth, strain fitness, motility, biofilm formation ability, survival in adverse conditions (oxidative stress and bile salts) and human serum and in vitro adhesion and invasion to Caco-2 cells was evaluated. We observed that the mutants from the three efflux pumps were more susceptible to several classes of antimicrobials than the parental strain and presented an increase in the accumulation of ethidium bromide, indicating a potential role of the efflux pumps in the extrusion of antimicrobials. The mutant strains had no bacterial growth defects; nonetheless, they presented a reduction in relative fitness. For the three mutants, an increase in the susceptibility to oxidative stress was observed, while only the mutant for AreGHI efflux pump showed a relevant role in bile stress survival. All the mutant strains showed an impairment in biofilm formation ability, were more susceptible to human serum and were less adherent to intestinal epithelial cells. Overall, the results support the contribution of the efflux pumps AreABC, AreDEF and AreGHI of A. butzleri to antimicrobial resistance, as well as to bacterial virulence.

scholarly journals Role of DegQ in differential stability of flagellin subunits in Vibrio vulnificus

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
You-Chul Jung ◽  
Mi-Ae Lee ◽  
Han-Shin Kim ◽  
Kyu-Ho Lee
Keyword(s):  
Life Cycle ◽  
Biofilm Formation ◽  
Vibrio Vulnificus ◽  
Differential Regulation ◽  
Specific Manner ◽  
Associated Proteins ◽  
Differential Stability ◽  
Methionine Residues

AbstractBiofilm formation of Vibrio vulnificus is initiated by adherence of flagellated cells to surfaces, and then flagellum-driven motility is not necessary during biofilm maturation. Once matured biofilms are constructed, cells become flagellated and swim to disperse from biofilms. As a consequence, timely regulations of the flagellar components’ expression are crucial to complete a biofilm life-cycle. In this study, we demonstrated that flagellins’ production is regulated in a biofilm stage-specific manner, via activities of a protease DegQ and a chaperone FlaJ. Among four flagellin subunits for V. vulnificus filament, FlaC had the highest affinities to hook-associated proteins, and is critical for maturating flagellum, showed the least susceptibility to DegQ due to the presence of methionine residues in its DegQ-sensitive domains, ND1 and CD0. Therefore, differential regulation by DegQ and FlaJ controls the cytoplasmic stability of flagellins, which further determines the motility-dependent, stage-specific development of biofilms.

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