scholarly journals Pseudomonas aeruginosa Bacteriophage PA1Ø Requires Type IV Pili for Infection and Shows Broad Bactericidal and Biofilm Removal Activities

2012 ◽  
Vol 78 (17) ◽  
pp. 6380-6385 ◽  
Author(s):  
Shukho Kim ◽  
Marzia Rahman ◽  
Sung Yong Seol ◽  
Sang Sun Yoon ◽  
Jungmin Kim
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Therapeutic Agent ◽  
Type Iv Pili ◽  
Mixed Infections ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Type Iv ◽  
Biofilm Removal

ABSTRACTWe isolated a new lyticPseudomonas aeruginosaphage that requires type IV pili for infection. PA1Ø has a broad bactericidal spectrum, covering Gram-positive and Gram-negative bacteria, and can eradicate biofilm cells. PA1Ø may be developed as a therapeutic agent for biofilm-related mixed infections withP. aeruginosaandStaphylococcus aureus.

scholarly journals Secretin channel-interactors prevent antibiotic influx during type IV pili assembly in P. aeruginosa

2021 ◽  
Author(s):  
Hongbaek Cho ◽  
Oh Hyun Kwon ◽  
Joel W Sher ◽  
Bi-o Kim ◽  
You-Hee Cho
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Bacterial Pathogenesis ◽  
Type Iv Pili ◽  
Permeability Barrier ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Type Iv ◽  
Periplasmic Proteins ◽  
And Function

Type IV pili (T4P) are important virulence factors involved in host attachment and other aspects of bacterial pathogenesis. In Gram-negative bacteria, the T4P filament is polymerized from pilin subunits at the platform complex in the inner membrane (IM) and exits the outer membrane (OM) through the OM secretin channel. Although it is essential for T4P assembly and function, the OM secretin complexes can potentially impair the permeability barrier function of the OM and allow the entry of antibiotics and other toxic molecules. The mechanism by which Gram-negative bacteria prevent secretin-mediated OM leakage is currently not well understood. Here, we report a discovery of SlkA and SlkB (PA5122 and PA5123) that prevent permeation of several classes of antibiotics through the secretin channel of Pseudomonas aeruginosa type IV pili. We found these periplasmic proteins interact with the OM secretin complex and prevent toxic molecules from entering through the channel when there is a problem in the assembly of the T4P IM subcomplexes or when docking between the OM and IM complexes is defective.

scholarly journals Construction of a Broad-Host-Range Tn7-Based Vector for Single-Copy PBAD-Controlled Gene Expression in Gram-Negative Bacteria

2012 ◽  
Vol 79 (2) ◽  
pp. 718-721 ◽  
Author(s):  
F. Heath Damron ◽  
Elizabeth S. McKenney ◽  
Herbert P. Schweizer ◽  
Joanna B. Goldberg
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Host Range ◽  
Single Copy ◽  
Broad Host Range ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Delivery Vector ◽  
Inducible Gene

ABSTRACTWe describe a mini-Tn7-based broad-host-range expression cassette for arabinose-inducible gene expression from the PBADpromoter. This delivery vector, pTJ1, can integrate a single copy of a gene into the chromosome of Gram-negative bacteria for diverse genetic applications, of which several are discussed, usingPseudomonas aeruginosaas the model host.

scholarly journals Cystic fibrosis pathogens survive for extended periods within cough-generated droplet nuclei

Thorax ◽  
2018 ◽  
Vol 74 (1) ◽  
pp. 87-90 ◽  
Author(s):  
Michelle E Wood ◽  
Rebecca E Stockwell ◽  
Graham R Johnson ◽  
Kay A Ramsay ◽  
Laura J Sherrard ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Cross Sectional Study ◽  
Gram Negative Bacteria ◽  
Sectional Study ◽  
Bacterial Strains ◽  
Cross Sectional ◽  
Gram Negative ◽  
Droplet Nuclei

The airborne route is a potential pathway in the person-to-person transmission of bacterial strains among cystic fibrosis (CF) populations. In this cross-sectional study, we investigate the physical properties and survival of common non-Pseudomonas aeruginosa CF pathogens generated during coughing. We conclude that Gram-negative bacteria and Staphylococcus aureus are aerosolised during coughing, can travel up to 4 m and remain viable within droplet nuclei for up to 45 min. These results suggest that airborne person-to-person transmission is plausible for the CF pathogens we measured.

scholarly journals National Surveillance of Antimicrobial Susceptibility of Bacteremic Gram-Negative Bacteria with Emphasis on Community-Acquired Resistant Isolates: Report from the 2019 Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART)

2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Po-Yu Liu ◽  
Yu-Lin Lee ◽  
Min-Chi Lu ◽  
Pei-Lan Shao ◽  
Po-Liang Lu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Gram Negative Bacteria ◽  
National Surveillance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

ABSTRACT A multicenter collection of bacteremic isolates of Escherichia coli (n = 423), Klebsiella pneumoniae (n = 372), Pseudomonas aeruginosa (n = 300), and Acinetobacter baumannii complex (n = 199) was analyzed for susceptibility. Xpert Carba-R assay and sequencing for mcr genes were performed for carbapenem- or colistin-resistant isolates. Nineteen (67.8%) carbapenem-resistant K. pneumoniae (n = 28) and one (20%) carbapenem-resistant E. coli (n = 5) isolate harbored blaKPC (n = 17), blaOXA-48 (n = 2), and blaVIM (n = 1) genes.

scholarly journals Susceptibility of Multiresistant Gram-Negative Bacteria to Fosfomycin and Performance of Different Susceptibility Testing Methods

2013 ◽  
Vol 58 (3) ◽  
pp. 1763-1767 ◽  
Author(s):  
L. V. Perdigão-Neto ◽  
M. S. Oliveira ◽  
C. F. Rizek ◽  
C. M. D. M. Carrilho ◽  
S. F. Costa ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Susceptibility Testing ◽  
Gram Negative Bacteria ◽  
Testing Methods ◽  
Gram Negative ◽  
Content Type ◽  
Agar Dilution ◽  
And Performance ◽  
Systemic Infections

ABSTRACTFosfomycin may be a treatment option for multiresistant Gram-negative bacteria. This study compared susceptibility methods using 94 multiresistant clinical isolates. With agar dilution (AD), susceptibilities were 81%, 7%, 96%, and 100% (CLSI) and 0%, 0%, 96%, and 30% (EUCAST), respectively, forAcinetobacter baumannii,Pseudomonas aeruginosa,Klebsiella pneumoniae, andEnterobacterspp. Categorical agreement between Etest and AD forEnterobacteriaceaeandA. baumanniiwas ≥80%. Disk diffusion was adequate only forEnterobacter. CLSI criteria for urine may be adequate for systemic infections.

scholarly journals Pseudomonas aeruginosa Contact-Dependent Growth Inhibition Plays Dual Role in Host-Pathogen Interactions

mSphere ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Jeffrey A. Melvin ◽  
Jordan R. Gaston ◽  
Shawn N. Phillips ◽  
Michael J. Springer ◽  
Christopher W. Marshall ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acute Infection ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Microbial Pathogenesis ◽  
Host Pathogen Interactions ◽  
Gram Negative ◽  
Content Type ◽  
Disease Outcomes ◽  
Host Pathogen

ABSTRACT How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance. Microorganisms exist in a diverse ecosystem and have evolved many different mechanisms for sensing and influencing the polymicrobial environment around them, utilizing both diffusible and contact-dependent signals. Contact-dependent growth inhibition (CDI) is one such communication system employed by Gram-negative bacteria. In addition to CDI mediation of growth inhibition, recent studies have demonstrated CDI-mediated control of communal behaviors such as biofilm formation. We postulated that CDI may therefore play an active role in host-pathogen interactions, allowing invading strains to establish themselves at polymicrobial mucosal interfaces through competitive interactions while simultaneously facilitating pathogenic capabilities via CDI-mediated signaling. Here, we show that Pseudomonas aeruginosa produces two CDI systems capable of mediating competition under conditions of growth on a surface or in liquid. Furthermore, we demonstrated a novel role for these systems in contributing to virulence in acute infection models, likely via posttranscriptional regulation of beneficial behaviors. While we did not observe any role for the P. aeruginosa CDI systems in biofilm biogenesis, we did identify for the first time robust CDI-mediated competition during interaction with a mammalian host using a model of chronic respiratory tract infection, as well as evidence that CDI expression is maintained in chronic lung infections. These findings reveal a previously unappreciated role for CDI in host-pathogen interactions and emphasize their importance during infection. IMPORTANCE How bacteria compete and communicate with each other is an increasingly recognized aspect of microbial pathogenesis with a major impact on disease outcomes. Gram-negative bacteria have recently been shown to employ a contact-dependent toxin-antitoxin system to achieve both competition and regulation of their physiology. Here, we show that this system is vital for virulence in acute infection as well as for establishment of chronic infection in the multidrug-resistant pathogen Pseudomonas aeruginosa. Greater understanding of the mechanisms underlying bacterial virulence and infection is important for the development of effective therapeutics in the era of increasing antimicrobial resistance.

scholarly journals The Swarming Motility of Pseudomonas aeruginosa Is Blocked by Cranberry Proanthocyanidins and Other Tannin-Containing Materials

2011 ◽  
Vol 77 (9) ◽  
pp. 3061-3067 ◽  
Author(s):  
Che O'May ◽  
Nathalie Tufenkji
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Adhesion ◽  
Type Iv Pili ◽  
Hydrolyzable Tannin ◽  
Swarming Motility ◽  
Subsequent Formation ◽  
Content Type ◽  
Type Iv ◽  
Derivatives Of ◽  
Growth Experiments

ABSTRACTBacterial motility plays a key role in the colonization of surfaces by bacteria and the subsequent formation of resistant communities of bacteria called biofilms. Derivatives of cranberry fruit, predominantly condensed tannins called proanthocyanidins (PACs) have been reported to interfere with bacterial adhesion, but the effects of PACs and other tannins on bacterial motilities remain largely unknown. In this study, we investigated whether cranberry PAC (CPAC) and the hydrolyzable tannin in pomegranate (PG; punicalagin) affected the levels of motilities exhibited by the bacteriumPseudomonas aeruginosa. This bacterium utilizes flagellum-mediated swimming motility to approach a surface, attaches, and then further spreads via the surface-associated motilities designated swarming and twitching, mediated by multiple flagella and type IV pili, respectively. Under the conditions tested, both CPAC and PG completely blocked swarming motility but did not block swimming or twitching motilities. Other cranberry-containing materials and extracts of green tea (also rich in tannins) were also able to block or impair swarming motility. Moreover, swarming bacteria were repelled by filter paper discs impregnated with many tannin-containing materials. Growth experiments demonstrated that the majority of these compounds did not impair bacterial growth. When CPAC- or PG-containing medium was supplemented with surfactant (rhamnolipid), swarming motility was partially restored, suggesting that the effective tannins are in part acting by a rhamnolipid-related mechanism. Further support for this theory was provided by demonstrating that the agar surrounding tannin-induced nonswarming bacteria was considerably less hydrophilic than the agar area surrounding swarming bacteria. This is the first study to show that natural compounds containing tannins are able to blockP. aeruginosaswarming motility and that swarming bacteria are repelled by such compounds.

scholarly journals Bacteriological Profile and Antimicrobial Susceptibility Patterns of Bacteria Isolated from Pus/Wound Swab Samples from Children Attending a Tertiary Care Hospital in Kathmandu, Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Salu Rai ◽  
Uday Narayan Yadav ◽  
Narayan Dutt Pant ◽  
Jaya Krishna Yakha ◽  
Prem Prasad Tripathi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Susceptibility ◽  
Gram Negative Bacteria ◽  
Wound Infections ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Wound Swab ◽  
Susceptibility Patterns

In Nepal, little is known about the microbiological profile of wound infections in children and their antimicrobial susceptibility patterns. Total of 450 pus/wound swab samples collected were cultured using standard microbiological techniques and the colonies grown were identified with the help of biochemical tests. The antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Methicillin-resistantStaphylococcus aureusisolates were detected by using cefoxitin disc and confirmed by determining minimum inhibitory concentrations (MIC) of oxacillin. 264 (59%) samples were culture positive. The highest incidence of bacterial infections was noted in the age group of less than 1 year (76%). Out of 264 growth positive samples, Gram-positive bacteria were isolated from 162 (61%) samples and Gram-negative bacteria were found in 102 (39%) samples.Staphylococcus aureus(99%) was the predominant Gram-positive bacteria isolated andPseudomonas aeruginosa(44%) was predominant Gram-negative bacteria. About 19% ofS. aureusisolates were found to be methicillin-resistant MIC of oxacillin ranging from 4 μg/mL to 128 μg/mL. Among the children of Nepal, those of age less than 1 year were at higher risk of wound infections by bacteria.Staphylococcus aureusfollowed byPseudomonas aeruginosawere the most common bacteria causing wound infections in children.

scholarly journals Green Synthesis of Silver Nanoparticles Using Novel Launaea Procumbens Leaves Extract and Screening Its Antibacterial Activity

2021 ◽  
Author(s):  
Sanjay Ratan Kumavat ◽  
SATYENDRA MISHRA
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Negative ◽  
Green Synthesized Silver Nanoparticles ◽  
Launaea Procumbens

Abstract Plants are emerging as a cost-effective and ecofriendly method for green synthesis of nanoparticles. The plant extract Launaea procumbens was used as a reduction agent in the green synthesis of silver nanoparticles. UV-Visible spectroscopy, HR-TEM, SAED, FE-SEM, EDAX, DLS, and FT-IR were used to study the green synthesized silver nanoparticles. UV-Vis spectroscopy of a prepared silver solution revealed maximum absorption at 435 nm. The synthesized silver nanoparticles were found to be spherical in shape with a size in the range of 24.28 to 31.54 nm. DLS analysis was used to determine the size of the green synthesized silver nanoparticles, which showed outstanding antibacterial action against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, as well as Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Gram-positive Bacillus subtilis had a maximum zone of inhibition of 20 mm, Staphylococcus aureus had a zone of inhibition of 19 mm, and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa had zones of inhibition of 13 mm.

scholarly journals Pathogenicity Genomic Island-Associated CrpP-Like Fluoroquinolone-Modifying Enzymes among Pseudomonas aeruginosa Clinical Isolates in Europe

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
José Manuel Ortiz de la Rosa ◽  
Patrice Nordmann ◽  
Laurent Poirel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Genomic Island ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Genomic Islands ◽  
Clinical Isolates ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Genes Encoding

ABSTRACT Many transferable quinolone resistance mechanisms have been identified in Gram-negative bacteria. The plasmid-encoded 65-amino-acid-long ciprofloxacin-modifying enzyme CrpP was recently identified in Pseudomonas aeruginosa isolates. We analyzed a collection of 100 clonally unrelated and multidrug-resistant P. aeruginosa clinical isolates, among which 46 were positive for crpP-like genes, encoding five CrpP variants conferring variable levels of reduced susceptibility to fluoroquinolones. These crpP-like genes were chromosomally located as part of pathogenicity genomic islands.

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