New integron gene arrays from multiresistant clinical isolates of members of the Enterobacteriaceae and Pseudomonas aeruginosa from hospitals in Malaysia

2013 ◽  
Vol 62 (3) ◽  
pp. 412-420 ◽  
Author(s):  
Sue-Bee Kor ◽  
Quok-Cheong Choo ◽  
Choy-Hoong Chew
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Isolates ◽  
Gene Arrays

scholarly journals Cephalosporin nitric oxide-donor prodrug DEA-C3D disperses biofilms formed by clinical cystic fibrosis isolates of Pseudomonas aeruginosa

2019 ◽  
Vol 75 (1) ◽  
pp. 117-125 ◽  
Author(s):  
Odel Soren ◽  
Ardeshir Rineh ◽  
Diogo G Silva ◽  
Yuming Cai ◽  
Robert P Howlin ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Clinical Isolates ◽  
Nitric Oxide Donor ◽  
Confocal Laser ◽  
Broth Microdilution Method

Abstract Objectives The cephalosporin nitric oxide (NO)-donor prodrug DEA-C3D (‘DiEthylAmin-Cephalosporin-3′-Diazeniumdiolate’) has been shown to initiate the dispersal of biofilms formed by the Pseudomonas aeruginosa laboratory strain PAO1. In this study, we investigated whether DEA-C3D disperses biofilms formed by clinical cystic fibrosis (CF) isolates of P. aeruginosa and its effect in combination with two antipseudomonal antibiotics, tobramycin and colistin, in vitro. Methods β-Lactamase-triggered release of NO from DEA-C3D was confirmed using a gas-phase chemiluminescence detector. MICs for P. aeruginosa clinical isolates were determined using the broth microdilution method. A crystal violet staining technique and confocal laser scanning microscopy were used to evaluate the effects of DEA-C3D on P. aeruginosa biofilms alone and in combination with tobramycin and colistin. Results DEA-C3D was confirmed to selectively release NO in response to contact with bacterial β-lactamase. Despite lacking direct, cephalosporin/β-lactam-based antibacterial activity, DEA-C3D was able to disperse biofilms formed by three P. aeruginosa clinical isolates. Confocal microscopy revealed that DEA-C3D in combination with tobramycin produces similar reductions in biofilm to DEA-C3D alone, whereas the combination with colistin causes near complete eradication of P. aeruginosa biofilms in vitro. Conclusions DEA-C3D is effective in dispersing biofilms formed by multiple clinical isolates of P. aeruginosa and could hold promise as a new adjunctive therapy to patients with CF.

Widespread of ESBL- and carbapenemase GES-type genes on carbapenem-resistant Pseudomonas aeruginosa clinical isolates: a multicenter study in Mexican hospitals

2015 ◽  
Vol 81 (2) ◽  
pp. 135-137 ◽  
Author(s):  
Ulises Garza-Ramos ◽  
Humberto Barrios ◽  
Fernando Reyna-Flores ◽  
Elsa Tamayo-Legorreta ◽  
Juan C. Catalan-Najera ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multicenter Study ◽  
Clinical Isolates ◽  
Carbapenem Resistant

scholarly journals Detection of Extended-Spectrum β-Lactamases in Clinical Isolates of Pseudomonas aeruginosa

2006 ◽  
Vol 50 (9) ◽  
pp. 2990-2995 ◽  
Author(s):  
Xiaofei Jiang ◽  
Zhe Zhang ◽  
Min Li ◽  
Danqiu Zhou ◽  
Feiyi Ruan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Screening Methods ◽  
Extended Spectrum ◽  
Pcr Product ◽  
Amoxicillin Clavulanate ◽  
Synergy Test ◽  
Esbl Producers ◽  
Disk Test

ABSTRACT With the occurrence of extended-spectrum β-lactamases (ESBLs) in Pseudomonas aeruginosa being increasingly reported worldwide, there is a need for a reliable test to detect ESBLs in clinical isolates of P. aeruginosa. In our study, a total of 75 clinical isolates of P. aeruginosa were studied. Nitrocefin tests were performed to detect the β-lactamase enzyme; isoelectric focusing electrophoresis, PCR, and PCR product sequencing were designed to further characterize the contained ESBLs. Various ESBL-screening methods were designed to compare the reliabilities of detecting ESBLs in clinical isolates of P. aeruginosa whose β-lactamases were well characterized. Thirty-four of 36 multidrug-resistant P. aeruginosa clinical isolates were positive for ESBLs. bla VEB-3 was the most prevalent ESBL gene in P. aeruginosa in our study. Among the total of 34 isolates that were considered ESBL producers, 20 strains were positive using conventional combined disk tests and 10 strains were positive using a conventional double-disk synergy test (DDST) with amoxicillin-clavulanate, expanded-spectrum cephalosporins, aztreonam, and cefepime. Modifications of the combined disk test and DDST, which consisted of shorter distances between disks (20 mm instead of 30 mm) and the use of three different plates that contained cloxacillin (200 μg/ml) alone, Phe-Arg β-naphthylamide dihydrochloride (MC-207,110; 20 μg/ml) alone, and both cloxacillin (200 μg/ml) and MC-207,110 (20 μg/ml) increased the sensitivity of the tests to 78.8%, 91.18%, 85.29%, and 97.06%.

scholarly journals Development of Multi-Drug Resistant Mutants of Clinical Isolates of Pseudomonas aeruginosa after Exposure to Fluoroquinolone

1996 ◽  
Vol 70 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Miyuki HASEGAWA ◽  
Intetsu KOBAYASHI ◽  
Takeshi SAIKA ◽  
Mitsunobu SHIMAZU ◽  
Minoru NISHIDA
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Clinical Isolates ◽  
Drug Resistant ◽  
Resistant Mutants

scholarly journals ampG Gene of Pseudomonas aeruginosa and Its Role in β-Lactamase Expression

2010 ◽  
Vol 54 (11) ◽  
pp. 4772-4779 ◽  
Author(s):  
Ying Zhang ◽  
Qiyu Bao ◽  
Luc A. Gagnon ◽  
Ann Huletsky ◽  
Antonio Oliver ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Transmembrane Protein ◽  
Amino Acid Identity ◽  
Clinical Isolates ◽  
Signal Molecules ◽  
Carbonyl Cyanide ◽  
Increased Sensitivity ◽  
Potential Strategy ◽  
High Level

ABSTRACT In enterobacteria, the ampG gene encodes a transmembrane protein (permease) that transports 1,6-GlcNAc-anhydro-MurNAc and the 1,6-GlcNAc-anhydro-MurNAc peptide from the periplasm to the cytoplasm, which serve as signal molecules for the induction of ampC β-lactamase. The role of AmpG as a transporter is also essential for cell wall recycling. Pseudomonas aeruginosa carries two AmpG homologues, AmpG (PA4393) and AmpGh1 (PA4218), with 45 and 41% amino acid sequence identity, respectively, to Escherichia coli AmpG, while the two homologues share only 19% amino acid identity. In P. aeruginosa strains PAO1 and PAK, inactivation of ampG drastically repressed the intrinsic β-lactam resistance while ampGh1 deletion had little effect on the resistance. Further, deletion of ampG in an ampD-null mutant abolished the high-level β-lactam resistance that is associated with the loss of AmpD activity. The cloned ampG gene is able to complement both the P. aeruginosa and the E. coli ampG mutants, while that of ampGh1 failed to do so, suggesting that PA4393 encodes the only functional AmpG protein in P. aeruginosa. We also demonstrate that the function of AmpG in laboratory strains of P. aeruginosa can effectively be inhibited by carbonyl cyanide m-chlorophenylhydrazone (CCCP), causing an increased sensitivity to β-lactams among laboratory as well as clinical isolates of P. aeruginosa. Our results suggest that inhibition of the AmpG activity is a potential strategy for enhancing the efficacy of β-lactams against P. aeruginosa, which carries inducible chromosomal ampC, especially in AmpC-hyperproducing clinical isolates.

Sign in / Sign up

Export Citation Format

Share Document