[Role of orfD Pseudomonas aeruginosa H103 gene in glucose uptake]

Pseudomonas aeruginosa is a gram negative non facultative bacterium and one of the members of normal flora in different sites of body in healthy humans. This bacterium can resist in fluids and hospital environments for a long time. Pseudomonas aeruginosa has two systems for glucose uptake: a low affinity oxidative pathway and a high affinity phosphorylative pathway. The orfBCD genes are located over two million base pair upstream of the genes involved in the high affinity uptake system. Although the role of these genes are unknown by now, they may have a role in regulation of glucose uptake. In the present study, the role of orfD gene in glucose uptake in P.aeruginosa has been investigated. orfD fragment were cloned in pUCP20 as vector and the recombinant plasmid transferred into WMA200 strain of P.aeruginosa, a mutant strain of P.aeruginosa with a chromosomal deletion of orfBCD. So we compared the rate of glucose uptake by P.aeruginosaWMA200, P.aeruginosaWMA200/pUCP20/orfD and P.aeruginosa H103 as wild type strain of P.aeruginosa by using labeled glucose under conditions at low substrate concentration and low cell density. Carbohydrate uptake patterns differed considerably among three strains. The wild type is able to uptake glucose at a faster rate than the mutant; however, the mutant complemented with orfD shows an intermediate uptake comparing to the wild type and the mutant.orfD gene has an important role in carbohydrate uptake in P.aeruginosa strains however further studies are required to determine the involved mechanism

Alginate extraction of Pseudomonas aeroginosa and study of penetration of antibiotic agents through alginate using a sandwich cup method

Pseudomonas aeroginosa is one of the most important opportunistic bacteria which produces biofilm. It has been reported that biofilm forming bacteria are more resistant to antibiotic treatment and immunologic response. Biofilms, communities of cells adhering to a surface enclosed in a self-producing polymeric matrix. Biofilms might be responsible for 65%of bacterial infections. In this study we investigated the role of the barrier formed by alginate against antibiotic penetration .Mucoid isolates of P. aeruginosa were collected from 2 hospitals and identified by biochemical tests. Strain M214 P. aeruginosa produces more biofilm compared with other strains. Alginate was extracted from mucoid type P. aeruginosa [M214] with method described by Goven. We evaluated the penetration of antibiotics macrolides [azithromycin,erythromycin],aminoglycosides [amikacin,gentamicin] lactames [imipenem,ceftazidem],fluoruqinolones [ciprofloxacin,ofloxacin] through P. aeruginosa [M214] alginate with a sandwich cup method described by Hiromi Kumon indicated that macrolides demonstrated penetration rate 100% .fluroquinolones and lactames demonstrated relatively high penetration rate>85%, whereas aminoglycosides showed low penetration [amikacin=59%,gentamicin=73%]. In this study, the role of alginate as a barrier against antibiotics penetration was proven