Jimmy Foulds

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Since the growth of wild-type Escherichia coli in salicylate results in a multiple antibiotic resistance phenotype similar to that of constitutive mutants (Mar) of the chromosomal mar locus, the effect of salicylate on the expression of the marRAB operon was investigated. The amount of RNA hybridizing with a mar-specific DNA probe was 5 to 10 times higher(More)
Wild-type Escherichia coli K-12 produces two porins, OmpF (protein 1a) and OmpC (protein 1b). In mutants deficient in both of these "normal" porins, secondary mutants that produce a "new" porin, protein PhoE (protein E), are selected for. We determined the properties of the channels produced by each of these porins by measuring the rates of diffusion of(More)
Escherichia coli strain JF694 contains a new major outer membrane protein which we have called protein E (J. Foulds, and T. Chai, J. Bacteriol. 133:1478-1483). Two new bacteriophages, TC45 and TC23, were isolated that require the presence of protein E in the outer membrane of host cells for growth. Both of these bacteriophages have a morphology similar to(More)
Several hundred independent bacteriocin-tolerant mutants have been isolated without mutagenesis from three strains of Escherichia coli. On the basis of patterns of sensitivity to eight different colicins, over 85% of these mutants could be grouped into four classes. Two classes of mutants, class A and class B, are equivalent to tolA and tolB type mutants.(More)
The tentative map position on the Escherichia coli chromosome of the tolF locus, determining tolerance to colicins A, E2, E3, K, and L, has been confirmed by three-point transduction. It lies between the aroA and pyrD loci at about 21 min on the linkage map of Bachmann et al. (1976). The cmlB locus, determining increased resistance to the antibiotics(More)
The phenotypic expression of protein E, a recently described major outer membrane protein, is associated with a mutation at a locus on the Escherichia coli chromosome that we call nmpA. nmpA is located between rbsK and uncA at 82.7 min on the E. coli linkage map. The nmpA locus is also the site of the mutations which lead to the formation of major outer(More)
We have shown recently that an average of three or more C9 molecules must bind to C5b-8 on Escherichia coli strain J5 to cause direct complement killing in the absence of serum lysozyme. We initially confirmed and extended this observation by showing that deposition of a large number of C5b-9 complexes bearing 1C9 per C5b-8 was not bactericidal for J5. To(More)
ompF cells were completely resistant to colicin A, whereas btuB cells were partially resistant. The OmpF protein, in the presence of added lipopolysaccharide, inactivated colicin A. This inactivation was enhanced by added btuB gene product, btuB gene product with lipopolysaccharide did not inactivate colicin A. These data, together with the observation that(More)