scholarly journals ClpV3 of the H3-Type VI Secretion System (H3-T6SS) Affects Multiple Virulence Factors in Pseudomonas aeruginosa

2020 ◽  
Vol 11 ◽  
Author(s):  
Yanqi Li ◽  
Lin Chen ◽  
Pansong Zhang ◽  
Anjali Y. Bhagirath ◽  
Kangmin Duan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Secretion System ◽  
Type Vi Secretion System ◽  
Type Vi Secretion

scholarly journals YbeY controls the type III and type VI secretion systems and biofilm formation through RetS in Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Yushan Xia ◽  
Congjuan Xu ◽  
Dan Wang ◽  
Yuding Weng ◽  
Yongxin Jin ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Type Iii Secretion ◽  
Biofilm Formation ◽  
Small Rnas ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Type Vi Secretion System ◽  
Chronic Infections ◽  
Type Iii ◽  
Type Vi Secretion

YbeY is a highly conserved RNase in bacteria and plays essential roles in the maturation of 16S rRNA, regulation of small RNAs (sRNAs) and bacterial responses to environmental stresses. Previously, we verified the role of YbeY in rRNA processing and ribosome maturation in Pseudomonas aeruginosa and demonstrated YbeY-mediated regulation of rpoS through a sRNA ReaL. In this study, we demonstrate that mutation of the ybeY gene results in upregulation of the type III secretion system (T3SS) genes as well as downregulation of the type VI secretion system (T6SS) genes and reduction of biofilm formation. By examining the expression of the known sRNAs in P. aeruginosa, we found that mutation of the ybeY gene leads to downregulation of the small RNAs RsmY/Z that control the T3SS, the T6SS and biofilm formation. Further studies revealed that the reduced levels of RsmY/Z are due to upregulation of retS. Taken together, our results reveal the pleiotropic functions of YbeY and provide detailed mechanisms of YbeY-mediated regulation in P. aeruginosa. IMPORTANCE Pseudomonas aeruginosa causes a variety of acute and chronic infections in humans. The type III secretion system (T3SS) plays an important role in acute infection and the type VI secretion system (T6SS) and biofilm formation are associated with chronic infections. Understanding of the mechanisms that control the virulence determinants involved in acute and chronic infections will provide clues for the development of effective treatment strategies. Our results reveal a novel RNase mediated regulation on the T3SS, T6SS and biofilm formation in P. aeruginosa.

scholarly journals Type VI Secretion System Dynamics Reveals a Novel Secretion Mechanism in Pseudomonas aeruginosa

2018 ◽  
Vol 200 (11) ◽  
Author(s):  
Jacqueline Corbitt ◽  
Jun Seok Yeo ◽  
C. Ian Davis ◽  
Michele LeRoux ◽  
Paul A. Wiggins
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Vibrio Cholerae ◽  
Conformational Change ◽  
Secretion System ◽  
Force Generation ◽  
Type Vi Secretion System ◽  
Content Type ◽  
Evolutionary Diversification ◽  
Type Vi Secretion ◽  
Generation Mechanisms

ABSTRACT The type VI secretion system (T6SS) inhibits the growth of neighboring bacterial cells through a contact-mediated mechanism. Here, we describe a detailed characterization of the protein localization dynamics in the Pseudomonas aeruginosa T6SS. It has been proposed that the type VI secretion process is driven by a conformational-change-induced contraction of the T6SS sheath. However, although the contraction of an optically resolvable TssBC sheath and the subsequent localization of ClpV are observed in Vibrio cholerae , coordinated assembly and disassembly of TssB and ClpV are observed without TssB contraction in P. aeruginosa . These dynamics are inconsistent with the proposed contraction sheath model. Motivated by the phenomenon of dynamic instability, we propose a new model in which ATP hydrolysis, rather than conformational change, generates the force for secretion. IMPORTANCE The type VI secretion system (T6SS) is widely conserved among Gram-negative bacteria and is a central determinant of bacterial fitness in polymicrobial communities. The secretion system targets bacteria and secretes effectors that inhibit the growth of neighboring cells, using a contact-mediated-delivery system. Despite significant homology to the previously characterized Vibrio cholerae T6SS, our analysis reveals that effector secretion is driven by a distinct force generation mechanism in Pseudomonas aeruginosa . The presence of two distinct force generation mechanisms in T6SS represents an example of the evolutionary diversification of force generation mechanisms.

scholarly journals Challenge of drug resistance in Pseudomonas aeruginosa: clonal spread of NDM-1-positive ST-308 within a tertiary hospital

2019 ◽  
Vol 74 (8) ◽  
pp. 2220-2224 ◽  
Author(s):  
Ka Lip Chew ◽  
Sophie Octavia ◽  
Oon Tek Ng ◽  
Kalisvar Marimuthu ◽  
Indumathi Venkatachalam ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Virulence Factors ◽  
Acquired Resistance ◽  
Hospital Setting ◽  
Tertiary Hospital ◽  
Secretion System ◽  
Type Vi Secretion System ◽  
Genomic Epidemiology ◽  
Global Threat

Abstract Objectives MDR Pseudomonas aeruginosa is a serious global threat to healthcare institutions. The mechanism by which drug resistance can be acquired is variable, but acquired carbapenemase production has been reported in P. aeruginosa. An investigation was performed to determine the rate and genomic epidemiology of New Delhi MBL (NDM) in β-lactam-non-susceptible isolates. Methods P. aeruginosa isolates from a tertiary hospital in Singapore between January 2015 and February 2018 were investigated for the presence of NDM genes. Results Out of 298 pan-β-lactam-non-susceptible isolates, 31 were found to be NDM positive (10.4%). WGS demonstrated that all 31 NDM-positive isolates were clonal, belonging to ST-308. blaNDM was chromosomally inserted within an integrative and conjugative element (ICE), ICETn43716385. The NDM-P. aeruginosa isolates possessed an extensive repertoire of both cell-associated [flagella, pili, alginate/biofilm, LPS, type III secretion system (T3SS) and type VI secretion system (T6SS)] and secreted virulence factors. Antibiograms revealed higher rates of drug resistance in NDM-positive isolates compared with their non-NDM counterparts. The NDM isolates remained 100% susceptible only to colistin. Conclusions The combination of chromosomal mutations, acquired resistance genes and virulence factors likely facilitated the persistent and ongoing spread of the ST-308 clade of P. aeruginosa within the hospital. Our study illustrates the particular threat of NDM-positive P. aeruginosa in a tertiary hospital setting in the era of antimicrobial resistance.

scholarly journals Host Adaptation Predisposes Pseudomonas aeruginosa to Type VI Secretion System-Mediated Predation by the Burkholderia cepacia Complex

2020 ◽  
Vol 28 (4) ◽  
pp. 534-547.e3 ◽  
Author(s):  
Andrew I. Perault ◽  
Courtney E. Chandler ◽  
David A. Rasko ◽  
Robert K. Ernst ◽  
Matthew C. Wolfgang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Burkholderia Cepacia ◽  
Host Adaptation ◽  
Secretion System ◽  
Burkholderia Cepacia Complex ◽  
Type Vi Secretion System ◽  
Type Vi Secretion

scholarly journals A Type VI Secretion System of Pseudomonas aeruginosa Targets a Toxin to Bacteria

2010 ◽  
Vol 7 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Rachel D. Hood ◽  
Pragya Singh ◽  
FoSheng Hsu ◽  
Tüzün Güvener ◽  
Mike A. Carl ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Secretion System ◽  
Type Vi Secretion System ◽  
Type Vi Secretion

scholarly journals Subinhibitory Concentration of Kanamycin Induces the Pseudomonas aeruginosa type VI Secretion System

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e81132 ◽  
Author(s):  
Cerith Jones ◽  
Luke Allsopp ◽  
Jack Horlick ◽  
Hemantha Kulasekara ◽  
Alain Filloux
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Secretion System ◽  
Subinhibitory Concentration ◽  
Type Vi Secretion System ◽  
Type Vi Secretion

scholarly journals The Type VI Secretion System of Pseudomonas aeruginosa: a gun loaded with antimicrobial bullets

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Sophie Howard ◽  
Chris Furniss ◽  
Dora Bonini ◽  
Himani Amin ◽  
Patricia Paracuellos-Torrecilla ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Respiratory Infections ◽  
Opportunistic Pathogen ◽  
Secretion System ◽  
Type Vi Secretion System ◽  
Type Vi Secretion ◽  
Interaction Partners ◽  
Bacterial Cytoplasm ◽  
Bacterial Effectors ◽  
Future Work

Pseudomonas aeruginosa is an opportunistic pathogen that can cause severe respiratory infections in people who are immunocompromised. P. aeruginosa possesses the Type VI Secretion System (T6SS), a bacterial weapon that injects effectors into neighbouring prokaryotes and eukaryotes. The T6SS is crucial for bacterial warfare, allowing P. aeruginosa to kill its competitors, which promotes its dominance in mixed microbial environments. P. aeruginosa has three T6SSs, H1/2/3-T6SS, these are structural homologs but deliver unique effectors. Effectors are delivered via the secreted component, a Hcp tube topped with a VgrG and PAAR spike. Only the first three identified effectors are delivered by Hcp1. Since then, there has been a bias in identification of VgrG or PAAR delivered effectors, mostly as these are encoded next to the spike proteins. Some P. aeruginosa effectors not only kill bacteria but have a dual role in pathogenesis. Our aim was to identify a comprehensive set of Hcp-delivered effectors for all three systems. Using Hcp1/2/3, systematic pull-down screens were performed to identify novel interaction partners. After confirming interaction, antibacterial toxicity was evaluated, identifying new Hcp delivered T6SS effectors for Hcp2 and Hcp3, which are toxic in the bacterial cytoplasm. These new anti-bacterial effectors may kill bacteria in novel ways, which could lead to novel antibiotics. Additionally, a toxin fusion proved too large for secretion and blocked the T6SS, revealing a Hcp-delivered effector size limit. Future work will focus on fully characterising these new toxins, as well as to look into the potential eukaryotic role of other interaction partners.

scholarly journals Host Adaptation Predisposes Pseudomonas aeruginosa to Type VI Secretion System-Mediated Predation by the Burkholderia cepacia Complex

2020 ◽  
Author(s):  
Andrew I Perault ◽  
Courtney E Chandler ◽  
David A Rasko ◽  
Robert K Ernst ◽  
Matthew C Wolfgang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Burkholderia Cepacia ◽  
Secretion System ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Dependent Manner ◽  
Type Vi Secretion System ◽  
Secretion Systems ◽  
Type Vi Secretion

SUMMARYPseudomonas aeruginosa (Pa) and Burkholderia cepacia complex (Bcc) species are opportunistic lung pathogens of individuals with cystic fibrosis (CF). While Pa can initiate long-term infections in younger CF patients, Bcc infections only arise in teenagers and adults. Both Pa and Bcc use type VI secretion systems (T6SS) to mediate interbacterial competition. Here, we show that Pa isolates from teenage/adult CF patients, but not those from young CF patients, are outcompeted by the epidemic Bcc isolate Burkholderia cenocepacia strain AU1054 (BcAU1054) in a T6SS-dependent manner. The genomes of susceptible Pa isolates harbor T6SS-abrogating mutations, the repair of which, in some cases, rendered the isolates resistant. Moreover, seven of eight Bcc strains outcompeted Pa strains isolated from the same patients. Our findings suggest that certain mutations that arise as Pa adapts to the CF lung abrogate T6SS activity, making Pa and its human host susceptible to potentially fatal Bcc superinfection.

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