scholarly journals Higher Prevalence of PldA, a Pseudomonas aeruginosa Trans-Kingdom H2-Type VI Secretion System Effector, in Clinical Isolates Responsible for Acute Infections and in Multidrug Resistant Strains

2018 ◽  
Vol 9 ◽  
Author(s):  
Thibaud Boulant ◽  
Yves-Marie Boudehen ◽  
Alain Filloux ◽  
Patrick Plesiat ◽  
Thierry Naas ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Secretion System ◽  
Clinical Isolates ◽  
Type Vi Secretion System ◽  
Type Vi Secretion ◽  
Acute Infections ◽  
Resistant Strains

scholarly journals A Novel Cecropin D-Derived Short Cationic Antimicrobial Peptide Exhibits Antibacterial Activity Against Wild-Type and Multidrug-Resistant Strains of Klebsiella pneumoniae and Pseudomonas aeruginosa

2020 ◽  
Vol 16 ◽  
pp. 117693432093626
Author(s):  
Iván Darío Ocampo-Ibáñez ◽  
Yamil Liscano ◽  
Sandra Patricia Rivera-Sánchez ◽  
José Oñate-Garzón ◽  
Ashley Dayan Lugo-Guevara ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Health Concern ◽  
Wild Type ◽  
Cationic Antimicrobial Peptide ◽  
Promising Alternative ◽  
Resistant Strains

Infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa and Klebsiella pneumoniae are a serious worldwide public health concern due to the ineffectiveness of empirical antibiotic therapy. Therefore, research and the development of new antibiotic alternatives are urgently needed to control these bacteria. The use of cationic antimicrobial peptides (CAMPs) is a promising candidate alternative therapeutic strategy to antibiotics because they exhibit antibacterial activity against both antibiotic susceptible and MDR strains. In this study, we aimed to investigate the in vitro antibacterial effect of a short synthetic CAMP derived from the ΔM2 analog of Cec D-like (CAMP-CecD) against clinical isolates of K pneumoniae (n = 30) and P aeruginosa (n = 30), as well as its hemolytic activity. Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of CAMP-CecD against wild-type and MDR strains were determined by the broth microdilution test. In addition, an in silico molecular dynamic simulation was performed to predict the interaction between CAMP-CecD and membrane models of K pneumoniae and P aeruginosa. The results revealed a bactericidal effect of CAMP-CecD against both wild-type and resistant strains, but MDR P aeruginosa showed higher susceptibility to this peptide with MIC values between 32 and >256 μg/mL. CAMP-CecD showed higher stability in the P aeruginosa membrane model compared with the K pneumoniae model due to the greater number of noncovalent interactions with phospholipid 1-Palmitoyl-2-oleyl-sn-glycero-3-(phospho-rac-(1-glycerol)) (POPG). This may be related to the boosted effectiveness of the peptide against P aeruginosa clinical isolates. Given the antibacterial activity of CAMP-CecD against wild-type and MDR clinical isolates of P aeruginosa and K pneumoniae and its nonhemolytic effects on human erythrocytes, CAMP-CecD may be a promising alternative to conventional antibiotics.

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 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 Multidrug-resistant plasmids repress chromosomally encoded T6SS to enable their dissemination

2019 ◽  
Vol 116 (4) ◽  
pp. 1378-1383 ◽  
Author(s):  
Gisela Di Venanzio ◽  
Ki Hwan Moon ◽  
Brent S. Weber ◽  
Juvenal Lopez ◽  
Pek Man Ly ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Secretion System ◽  
Cell Contact ◽  
Nosocomial Pathogen ◽  
Type Vi Secretion System ◽  
Active Type ◽  
Type Vi Secretion ◽  
Plasmid Conjugation

Acinetobacter baumannii (Ab) is a nosocomial pathogen with one of the highest rates of multidrug resistance (MDR). This is partially due to transmissible plasmids. Many Ab strains harbor a constitutively active type VI secretion system (T6SS) that is employed to kill nonkin bacteria. T6SS and plasmid conjugation both involve cell-to-cell contact. Paradoxically, successful conjugation requires the survival of the recipient, which is the target of the T6SS. Thus, an active T6SS in either the donor or the recipient poses a challenge to plasmid conjugation. Here, we show that large conjugative MDR plasmids heavily rely on their distinctive ability to repress the T6SS of their hosts to enable their own dissemination and the conjugation of other plasmids, contributing to the propagation of MDR among Acinetobacter isolates.

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
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