scholarly journals Replication of the Ordered, Nonredundant Library of Pseudomonas aeruginosa strain PA14 Transposon Insertion Mutants

10.3791/57298 ◽  
2018 ◽  
Author(s):  
Eliana Drenkard ◽  
Rhianna M. Hibbler ◽  
D. Alina Gutu ◽  
Alexander D. Eaton ◽  
Amy L. Silverio ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transposon Insertion ◽  
Insertion Mutants

scholarly journals An ordered, nonredundant library of Pseudomonas aeruginosa strain PA14 transposon insertion mutants

2006 ◽  
Vol 103 (8) ◽  
pp. 2833-2838 ◽  
Author(s):  
N. T. Liberati ◽  
J. M. Urbach ◽  
S. Miyata ◽  
D. G. Lee ◽  
E. Drenkard ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transposon Insertion ◽  
Insertion Mutants

scholarly journals Autolysis and Autoaggregation in Pseudomonas aeruginosa Colony Morphology Mutants

2002 ◽  
Vol 184 (23) ◽  
pp. 6481-6489 ◽  
Author(s):  
David A. D'Argenio ◽  
M. Worth Calfee ◽  
Paul B. Rainey ◽  
Everett C. Pesci
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Natural Populations ◽  
Transposon Insertion ◽  
Extracellular Signal ◽  
Chemosensory Pathway ◽  
Ggdef Domain ◽  
The Many ◽  
Suppressor Analysis ◽  
Fimbrial Adhesin ◽  
Insertion Mutants

ABSTRACT Two distinctive colony morphologies were noted in a collection of Pseudomonas aeruginosa transposon insertion mutants. One set of mutants formed wrinkled colonies of autoaggregating cells. Suppressor analysis of a subset of these mutants showed that this was due to the action of the regulator WspR and linked this regulator (and the chemosensory pathway to which it belongs) to genes that encode a putative fimbrial adhesin required for biofilm formation. WspR homologs, related in part by a shared GGDEF domain, regulate cell surface factors, including aggregative fimbriae and exopolysaccharides, in diverse bacteria. The second set of distinctive insertion mutants formed colonies that lysed at their center. Strains with the most pronounced lysis overproduced the Pseudomonas quinolone signal (PQS), an extracellular signal that interacts with quorum sensing. Autolysis was suppressed by mutation of genes required for PQS biosynthesis, and in one suppressed mutant, autolysis was restored by addition of synthetic PQS. The mechanism of autolysis may involve activation of the endogenous prophage and phage-related pyocins in the genome of strain PAO1. The fact that PQS levels correlated with autolysis suggests a fine balance in natural populations of P. aeruginosa between survival of the many and persistence of the few.

scholarly journals Genome Diversity of Pseudomonas aeruginosa PAO1 Laboratory Strains

2009 ◽  
Vol 192 (4) ◽  
pp. 1113-1121 ◽  
Author(s):  
Jens Klockgether ◽  
Antje Munder ◽  
Jens Neugebauer ◽  
Colin F. Davenport ◽  
Frauke Stanke ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Opportunistic Pathogen ◽  
Stationary Growth Phase ◽  
Infection Model ◽  
Nucleotide Substitutions ◽  
Single Nucleotide ◽  
Sequencing Project ◽  
Transposon Insertion ◽  
The University ◽  
Insertion Mutants

ABSTRACT Pseudomonas aeruginosa PAO1 is the most commonly used strain for research on this ubiquitous and metabolically versatile opportunistic pathogen. Strain PAO1, a derivative of the original Australian PAO isolate, has been distributed worldwide to laboratories and strain collections. Over decades discordant phenotypes of PAO1 sublines have emerged. Taking the existing PAO1-UW genome sequence (named after the University of Washington, which led the sequencing project) as a blueprint, the genome sequences of reference strains MPAO1 and PAO1-DSM (stored at the German Collection for Microorganisms and Cell Cultures [DSMZ]) were resolved by physical mapping and deep short read sequencing-by-synthesis. MPAO1 has been the source of near-saturation libraries of transposon insertion mutants, and PAO1-DSM is identical in its SpeI-DpnI restriction map with the original isolate. The major genomic differences of MPAO1 and PAO1-DSM in comparison to PAO1-UW are the lack of a large inversion, a duplication of a mobile 12-kb prophage region carrying a distinct integrase and protein phosphatases or kinases, deletions of 3 to 1,006 bp in size, and at least 39 single-nucleotide substitutions, 17 of which affect protein sequences. The PAO1 sublines differed in their ability to cope with nutrient limitation and their virulence in an acute murine airway infection model. Subline PAO1-DSM outnumbered the two other sublines in late stationary growth phase. In conclusion, P. aeruginosa PAO1 shows an ongoing microevolution of genotype and phenotype that jeopardizes the reproducibility of research. High-throughput genome resequencing will resolve more cases and could become a proper quality control for strain collections.

scholarly journals AcrAB Multidrug Efflux Pump Is Associated with Reduced Levels of Susceptibility to Tigecycline (GAR-936) in Proteus mirabilis

2003 ◽  
Vol 47 (2) ◽  
pp. 665-669 ◽  
Author(s):  
Melissa A. Visalli ◽  
Ellen Murphy ◽  
Steven J. Projan ◽  
Patricia A. Bradford
Keyword(s):  
Proteus Mirabilis ◽  
Efflux Pump ◽  
Wild Type ◽  
Multidrug Efflux ◽  
Multidrug Efflux Pump ◽  
Transposon Insertion ◽  
Spectrum Activity ◽  
Insertion Mutants ◽  
Broad Spectrum Activity ◽  
Increased Susceptibility

ABSTRACT Tigecycline has good broad-spectrum activity against many gram-positive and gram-negative pathogens with the notable exception of the Proteeae. A study was performed to identify the mechanism responsible for the reduced susceptibility to tigecycline in Proteus mirabilis. Two independent transposon insertion mutants of P. mirabilis that had 16-fold-increased susceptibility to tigecycline were mapped to the acrB gene homolog of the Escherichia coli AcrRAB efflux system. Wild-type levels of decreased susceptibility to tigecycline were restored to the insertion mutants by complementation with a clone containing a PCR-derived fragment from the parental wild-type acrRAB efflux gene cluster. The AcrAB transport system appears to be associated with the intrinsic reduced susceptibility to tigecycline in P. mirabilis.

scholarly journals Multiple Elements Controlling Adherence of Enterohemorrhagic Escherichia coli O157:H7 to HeLa Cells

2003 ◽  
Vol 71 (9) ◽  
pp. 4985-4995 ◽  
Author(s):  
Alfredo G. Torres ◽  
James B. Kaper
Keyword(s):  
Escherichia Coli ◽  
Hela Cells ◽  
Culture Conditions ◽  
Enterohemorrhagic Escherichia Coli ◽  
Differentially Expressed ◽  
Wild Type ◽  
Transposon Insertion ◽  
Reduced Adherence ◽  
Insertion Mutants

ABSTRACT Adherence of enterohemorrhagic Escherichia coli (EHEC) to the intestinal epithelium is essential for initiation of infection. Intimin is the only factor demonstrated to play a role in intestinal colonization by EHEC O157:H7. Other attempts to identify additional adhesion factors in vitro have been unsuccessful, suggesting that expression of these factors is under tight regulation. We sought to identify genes involved in the control of adherence of EHEC O157:H7 to cultured epithelial cells. A total of 5,000 independent transposon insertion mutants were screened for their ability to adhere to HeLa cells, and 7 mutants were isolated with a markedly enhanced adherence. The mutants adhered at levels 113 to 170% that of the wild-type strain, and analysis of the protein profiles of these mutants revealed several proteins differentially expressed under in vitro culture conditions. We determined the sequence of the differentially expressed proteins and further investigated the function of OmpA, whose expression was increased in a mutant with an insertionally inactivated tcdA gene. An isogenic ompA mutant showed reduced adherence compared to the parent strain. Disruption of the ompA gene in the tdcA mutant strain abolished the hyperadherent phenotype, and anti-OmpA serum inhibited adhesion of wild-type and tdcA mutant strains to HeLa cells. Enhanced adhesion mediated by OmpA was also observed with Caco-2 cells, and anti-OmpA serum blocked adherence to HeLa cells of other EHEC O157:H7 strains. Our results indicate that multiple elements control adherence and OmpA acts as an adhesin in EHEC O157:H7.

scholarly journals Identification of gmhA, a Yersinia pestis Gene Required for Flea Blockage, by Using a Caenorhabditis elegans Biofilm System

2005 ◽  
Vol 73 (11) ◽  
pp. 7236-7242 ◽  
Author(s):  
Creg Darby ◽  
Sandya L. Ananth ◽  
Li Tan ◽  
B. Joseph Hinnebusch
Keyword(s):  
Caenorhabditis Elegans ◽  
Yersinia Pestis ◽  
Biofilm Formation ◽  
Yersinia Pseudotuberculosis ◽  
C Elegans ◽  
Transposon Insertion ◽  
Insertion Mutants ◽  
Random Screening

ABSTRACT Yersinia pestis, the cause of bubonic plague, blocks feeding by its vector, the flea. Recent evidence indicates that blockage is mediated by an in vivo biofilm. Y. pestis and the closely related Yersinia pseudotuberculosis also make biofilms on the cuticle of the nematode Caenorhabditis elegans, which block this laboratory animal's feeding. Random screening of Y. pseudotuberculosis transposon insertion mutants with a C. elegans biofilm assay identified gmhA as a gene required for normal biofilms. gmhA encodes phosphoheptose isomerase, an enzyme required for synthesis of heptose, a conserved component of lipopolysaccharide and lipooligosaccharide. A Y. pestis gmhA mutant was constructed and was severely defective for C. elegans biofilm formation and for flea blockage but only moderately defective in an in vitro biofilm assay. These results validate use of the C. elegans biofilm system to identify genes and pathways involved in Y. pestis flea blockage.

scholarly journals Genome plasticity favours double chromosomal Tn4401b-blaKPC-2 transposon insertion in the Pseudomonas aeruginosa ST235 clone

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Deisy Abril ◽  
Ricaurte Alejandro Marquez-Ortiz ◽  
Betsy Castro-Cardozo ◽  
José Ignacio Moncayo-Ortiz ◽  
Narda María Olarte Escobar ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Genome Plasticity ◽  
Transposon Insertion

scholarly journals Effect of Metabolic Imbalance on Expression of Type III Secretion Genes in Pseudomonas aeruginosa

2004 ◽  
Vol 72 (3) ◽  
pp. 1383-1390 ◽  
Author(s):  
Arne Rietsch ◽  
Matthew C. Wolfgang ◽  
John J. Mekalanos
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Type Iii Secretion ◽  
Cell Contact ◽  
Insertion Mutant ◽  
Insertion Mutation ◽  
Type Iii ◽  
Transposon Insertion ◽  
Metabolic Imbalance ◽  
Cell Expression

ABSTRACT The type III secretion system is a dedicated machinery used by many pathogens to deliver toxins directly into the cytoplasm of a target cell. Expression and secretion of the type III effectors are triggered by cell contact. In Pseudomonas aeruginosa and Yersinia spp., expression can be triggered in vitro by removing calcium from the medium. The mechanism underlying either mode of regulation is unclear. Here we characterize a transposon insertion mutant of P. aeruginosa PAO1 that displays a marked defect in cytotoxicity. The insertion is located upstream of several genes involved in histidine utilization and impedes the ability of PAO1 to intoxicate eukaryotic cells effectively in a type III-dependent fashion. This inhibition depends on the presence of histidine in the medium and appears to depend on the excessive uptake and catabolism of histidine. The defect in cytotoxicity is mirrored by a decrease in exoS expression. Other parameters such as growth or piliation are unaffected. The cytotoxicity defect is partially complemented by an insertion mutation in cbrA that also causes overexpression of cbrB. The cbrAB two-component system has been implicated in sensing and responding to a carbon-nitrogen imbalance. Taken together, these results suggest that the metabolic state of the cell influences expression of the type III regulon.

Sign in / Sign up

Export Citation Format

Share Document