Porin (341 amino acids; mass of 37,782 Da) in the outer membrane of Haemophilus influenzae type b (Hib) permits diffusion into the periplasm of small solutes up to a molecular mass of 1400 Da. Molecular modeling of Hib porin identified its structural similarities to OmpF of Escherichia coli and disclosed for Hib porin a shorter length of loop 3 and a longer length of loop 4. By site-directed mu...

Bordetella pertussis 18323 produces a bvg-regulated 39.1-kDa porin-like protein, OmpQ. OmpQ had 61% similarity to the major porin of B. pertussis and contains conserved regions common to both the neisserial and enteric porin families. The results of Southern blot analysis indicate that strains of Bordetella parapertussis and Bordetella bronchiseptica but not Bordetella avium contain this gene.

Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 An oligonucleotide that encodes the N-terminal portion of a 41 kDa porin of Serratia marcescens was used to probe S. marcescens UOC-51 genomic DNA. An 11 kb EcoRl fragment which hybridized with the oligonucleotide was subcloned into Escherichia coli, examined for expression, and sequenced. The product express...

Objective (s) Porin is a mitochondrial outer membrane channel, which usually functions as the pathway for the movement of various substances in and out of the mitochondria and is considered to be a component of the permeability transition (PT) pore complex that plays a role in the PT. We addressed the hypothesis that porin interacts with other mitochondrial proteins after ischemic injury. Mater...

Resistance mechanisms in a group of carbapenemase-negative Pseudomonas aeruginosa that were susceptible to all antibiotics except carbapenems (carbapenem resistance-only P. aeruginosa [CROPA]) were studied. Ten genetically nonrelated CROPA isolates and their carbapenem-susceptible counterparts were further investigated. OprD production was demonstrated by protein electrophoresis in only 1 of th...

The gene encoding porin protein F of Pseudomonas aeruginosa was cloned onto a cosmid vector into Escherichia coli. Protein F was expressed as the predominant outer membrane protein in a porin-deficient E. coli background and was clearly visible on one-dimensional sodium dodecyl sulfate-polyacrylamide gels in a porin-sufficient background. The identity of the protein F from the E. coli clone and...

Introduction of the romA gene cloned from Enterobacter cloacae into Escherichia coli K-12 resulted in almost complete inhibition of OmpF expression and a concomitant increase in resistance to quinolones, beta-lactams, chloramphenicol, and tetracyclines. In addition, the romA gene reduced the susceptibility to these multiple drugs even in the OmpF porin-deficient mutants of E. coli K-12. Results...

We report here the complete genome sequence of a panresistant Pseudomonas aeruginosa strain, isolated from a patient with respiratory failure in Canada. No carbapenemase genes were identified. Carbapenem resistance is attributable to a frameshift in the oprD gene; the basis for colistin resistance remains undetermined.