scholarly journals T3SS and alginate biosynthesis of Pseudomonas aeruginosa impair healing of infected rabbit wounds

2020 ◽  
Vol 147 ◽  
pp. 104254
Author(s):  
S. L. Rajasekhar Karna ◽  
Jesse Q. Nguyen ◽  
Shankar Jaikishan Evani ◽  
Li-Wu Qian ◽  
Ping Chen ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Infected Rabbit ◽  
Alginate Biosynthesis

scholarly journals Genetic Determinants Involved in the Susceptibility of Pseudomonas aeruginosa to β-Lactam Antibiotics

2010 ◽  
Vol 54 (10) ◽  
pp. 4159-4167 ◽  
Author(s):  
Carolina Alvarez-Ortega ◽  
Irith Wiegand ◽  
Jorge Olivares ◽  
Robert E. W. Hancock ◽  
José Luis Martínez
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Detailed Analysis ◽  
Barrier Function ◽  
Mechanisms Of Action ◽  
Mutant Library ◽  
Genetic Determinants ◽  
Intrinsic Resistance ◽  
Resistance Phenotype ◽  
Mixed Phenotype ◽  
Alginate Biosynthesis

ABSTRACT The resistome of P. aeruginosa for three β-lactam antibiotics, namely, ceftazidime, imipenem, and meropenem, was deciphered by screening a comprehensive PA14 mutant library for mutants with increased or reduced susceptibility to these antimicrobials. Confirmation of the phenotypes of all selected mutants was performed by Etest. Of the total of 78 confirmed mutants, 41 demonstrated a reduced susceptibility phenotype and 37 a supersusceptibility (i.e., altered intrinsic resistance) phenotype, with 6 mutants demonstrating a mixed phenotype, depending on the antibiotic. Only three mutants demonstrated reduced (PA0908) or increased (glnK and ftsK) susceptibility to all three antibiotics. Overall, the mutant profiles of susceptibility suggested distinct mechanisms of action and resistance for the three antibiotics despite their similar structures. More detailed analysis indicated important roles for novel and known β-lactamase regulatory genes, for genes with likely involvement in barrier function, and for a range of regulators of alginate biosynthesis.

Roles of Mn2+, Mg2+ and Ca2+ on alginate biosynthesis by Pseudomonas aeruginosa

1990 ◽  
Vol 12 (10) ◽  
pp. 794-799 ◽  
Author(s):  
Lígia O. Martins ◽  
Luísa C. Brito ◽  
Isabel Sá-Correia
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alginate Biosynthesis

scholarly journals Phosphorylation of the Pseudomonas aeruginosa Response Regulator AlgR Is Essential for Type IV Fimbria-Mediated Twitching Motility

2002 ◽  
Vol 184 (16) ◽  
pp. 4544-4554 ◽  
Author(s):  
Cynthia B. Whitchurch ◽  
Tatiana E. Erova ◽  
Jacqui A. Emery ◽  
Jennifer L. Sargent ◽  
Jonathan M. Harris ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Response Regulator ◽  
Phosphorylation Site ◽  
Twitching Motility ◽  
Type Iv ◽  
Molecular Events ◽  
And Function ◽  
Alginate Biosynthesis

ABSTRACT The response regulator AlgR is required for both alginate biosynthesis and type IV fimbria-mediated twitching motility in Pseudomonas aeruginosa. In this study, the roles of AlgR signal transduction and phosphorylation in twitching motility and biofilm formation were examined. The predicted phosphorylation site of AlgR (aspartate 54) and a second aspartate (aspartate 85) in the receiver domain of AlgR were mutated to asparagine, and mutant algR alleles were introduced into the chromosome of P. aeruginosa strains PAK and PAO1. Assays of these mutants demonstrated that aspartate 54 but not aspartate 85 of AlgR is required for twitching motility and biofilm initiation. However, strains expressing AlgR D85N were found to be hyperfimbriate, indicating that both aspartate 54 and aspartate 85 are involved in fimbrial biogenesis and function. algD mutants were observed to have wild-type twitching motility, indicating that AlgR control of twitching motility is not mediated via its role in the control of alginate biosynthesis. In vitro phosphorylation assays showed that AlgR D54N is not phosphorylated by the enteric histidine kinase CheA. These findings indicate that phosphorylation of AlgR most likely occurs at aspartate 54 and that aspartate 54 and aspartate 85 of AlgR are required for the control of the molecular events governing fimbrial biogenesis, twitching motility, and biofilm formation in P. aeruginosa.

scholarly journals Evaluation of Antibiotic Tolerance in Pseudomonas aeruginosa for Aminoglycosides and its Prediction of Resistance Development Through In-silico Transcriptomic Analysis

2021 ◽  
Author(s):  
Abishek Kumar B ◽  
Bency Thankappan ◽  
Angayarkanni Jayaraman ◽  
Akshita Gupta
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Gene Expressions ◽  
Resistance Development ◽  
Adaptive Resistance ◽  
Antibiotic Response ◽  
Secretory System ◽  
Kinetics Of ◽  
Alginate Biosynthesis

Pseudomonas aeruginosa causes severe life-threatening infections and are difficult to treat. The lack of antibiotic response in P. aeruginosa is due to adaptive resistance, which prevents the entry of antibiotics into cytosol of the cell. Among different groups of antibiotics, aminoglycosides show superior antibiotic response and are used as a parental antibiotic for treatment. This study aims to determine the kinetics of adaptive resistance development and gene expression changes in P. aeruginosa exposed to amikacin, gentamicin, and tobramycin. In vitro antibiotic exposure to P. aeruginosa was performed and optical density of the cells were monitored for every 12 hours until 72 hours. The growth pattern plotted in graph represents the kinetics of adaptive resistance developed to respective antibiotics. The transcriptomic profile of P. aeruginosa PA14 to post exposed antibiotic was taken from Gene Expression Omnibus (GEO), NCBI. The gene expressions of two datasets were analyzed by case-control study. Tobramycin exposed P. aeruginosa failed to develop adaptive resistance in 0.5ug/mL, 1ug/mL and 1.5ug/mL of its MIC. Whereas, amikacin and gentamicin treated P. aeruginosa developed tolerance in the inhibitory concentrations of the antibiotics. This depicts the superior in vitro response of tobramycin over the gentamicin and amikacin. Furthermore, tobramycin treated P. aeruginosa microarray analysis resulted in low expression of catalytic enzyme 16s rRNA Methyltransferase E, B & L, alginate biosynthesis genes and several proteins of Type 2 Secretory System (T2SS) and Type 3 Secretory System (T3SS). The Differentially Expressed Genes (DEGs) of alginate biosynthesis, and RNA Methyltransferases suggests increased antibiotic response and low probability of developing resistance. The use of tobramycin as a parental antibiotic with its synergistic combination might combat P. aeruginosa with increased response.

The pathway of alginate biosynthesis in Pseudomonas aeruginosa

1985 ◽  
Vol 13 (6) ◽  
pp. 1148-1149 ◽  
Author(s):  
J. WINGENDER ◽  
V. SHERBROCK-COX ◽  
P. GACESA ◽  
N. J. RUSSELL
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alginate Biosynthesis

scholarly journals Alginate Lyase (AlgL) Activity Is Required for Alginate Biosynthesis in Pseudomonas aeruginosa

2005 ◽  
Vol 187 (11) ◽  
pp. 3869-3872 ◽  
Author(s):  
Mark T. Albrecht ◽  
Neal L. Schiller
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Enzymatic Activity ◽  
Alginate Lyase ◽  
Alginate Production ◽  
Lyase Activity ◽  
Alginate Biosynthesis

ABSTRACT To determine whether AlgL's lyase activity is required for alginate production in Pseudomonas aeruginosa, an algLΔ::Gmr mutant (FRD-MA7) was created. algL complementation of FRD-MA7 restored alginate production, but algL constructs containing mutations inactivating lyase activity did not, demonstrating that the enzymatic activity of AlgL is required for alginate production.

Sign in / Sign up

Export Citation Format

Share Document