Doripenem is a broad-spectrum parenteral carbapenem under clinical development in Japan and North America. Its activities against (i) Pseudomonas aeruginosa isolates with graded levels of intrinsic efflux-type resistance, (ii) mutants with various combinations of AmpC and OprD expression, (iii) PU21 transconjugants with class A and D beta-lactamases, and (iv) P. aeruginosa isolates with metallo...

An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosa isolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes encoding β-lactamases, aminoglycoside-m...

In order to define the contributions of the mechanisms for carbapenem resistance in clinical strains of Pseudomonas aeruginosa, we investigated the presence of OprD, the expressions of the MexAB-OprM and MexEF-OprN systems, and the production of the beta-lactamases for 44 clinical strains. All of the carbapenem-resistant isolates showed the loss of or decreased levels of OprD. Three strains ove...

Background: The opportunistic human pathogen, Pseudomonas aeruginosa, is a critical cause of nosocomial infection with high morbidity and mortality rate. Eradication P. aeruginosa has been troublesome due to its capacity develop strong multidrug resistance (MDR). Objectives: purposes this study were define the pattern antimicrobial sensitivity, typing, prevalence metallo-β-lactamase (MBL) detec...

The activity of imipenem against Pseudomonas aeruginosa HUS-3 decreased by 16 times in the presence of substances eluted from siliconized latex urinary catheters (SLUCs). SLUCs did not inactivate imipenem or increase beta-lactamase activity. The outer membrane of P. aeruginosa HUS-3 grown in the presence of eluate lacked an OprD-like protein and expressed a new 50-kDa protein. The decreased act...

Introduction: The major resistance mechanisms of Pseudomonas aeruginosa to fluoroquinolones and carbapenems are associated with the mutations in the genes gyrA and oprD encoding type II topoisomerases (DNA gyrase) and OprD porin, respectively. Method: In this cross-sectional study, sixty five clinical samples were collected from patients hospitalized in Al-Zahra Hospital of Isfahan, Iran. Susce...

background and objectives: the oprd mutation and ampc overproduction are the main mechanisms of intrinsic resistance to carbapenems such as imipenem and meropenem in pseudomonas aeruginosa . materials and methods: in this study, we investigated intrinsic resistance to carbapenems including mutation of oprd and ampc overproduction in a carbapenem-resistant p. aeruginosa isolated from a burn pati...