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Pseudomonas aeruginosa secretes multiple proteases that have been implicated as virulence factors and the detection of each specific enzyme can be difficult to determine. Unlike the three Pseudomonas enzymes that have been well characterized (elastase A, elastase B, and alkaline protease), the activity of protease IV in multiple assays has yet to be(More)
Staphylococcus aureus produces a variety of proteins, including alpha-toxin and protein A, that could contribute to corneal tissue damage during keratitis. We examined corneal infections produced by intrastromal injection of four S. aureus strains--three isogenic mutants, one lacking alpha-toxin (Hly- Spa+), one lacking protein A (Hly+ Spa-), and one(More)
Glutathione S-transferases are important in the detoxification of a wide range of human carcinogens. Previous studies have shown inconsistent associations between the GSTT1 and GSTM1 null genotypes and stomach cancer risk. We investigated the relationship between these and related genotypes and stomach cancer risk in a population-based case-control study in(More)
Comparisons of virulence between a Pseudomonas parent strain and an isogenic mutant devoid of protease IV have demonstrated a significant role for this enzyme during infection. We have characterized purified Pseudomonas aeruginosa protease IV in terms of its biochemical and enzymatic properties, and found it to be a unique extracellular protease. The(More)
PURPOSE The role of protease IV in the pathogenesis of Pseudomonas aeruginosa keratitis was investigated by comparing a mutant strain completely deficient in protease IV activity with its protease IV activity-producing parent. METHODS A protease IV-deficient Pseudomonas strain PA103-29::Tn9 was generated by mutagenesis of strain PA103-29, which produces(More)
PURPOSE A Pseudomonas mutant deficient in protease IV has significantly reduced virulence in experimental keratitis. In the present study, the corneal toxicity of purified protease IV and its ability to augment the virulence of protease-IV-deficient bacteria were analyzed. METHODS The toxicity of purified protease IV was determined by intrastromally(More)
This study was conducted to determine the therapeutic efficacy of 3.0 mg/ml ciprofloxacin administered concurrently with one of two salts of prednisolone for the treatment of experimental pseudomonal keratitis. Rabbit corneas were injected intrastromally with Pseudomonas aeruginosa ATCC strain 27853. Sixteen hr after injection, rabbits were randomly divided(More)
This study was conducted to determine whether the age of the host influences the pathogenesis and therapeutic outcome of drug-treated Pseudomonas aeruginosa keratitis. Young (3- to 5-month-old) and old (1.5- to 3-year-old) rabbits were intrastromally infected with P. aeruginosa ATCC 27853. Sixteen hours later, rabbits in both age subpopulations were divided(More)
Ciprofloxacin and prednisolone, but not an aminoglycoside and dexamethasone, were previously found to be effective in killing bacteria and reducing inflammation for the treatment of Pseudomonas keratitis. We investigated the therapeutic effectiveness of tobramycin/prednisolone and ciprofloxacin/dexamethasone in a rabbit model of experimental keratitis to(More)
  • Lee S Engel
  • 2010
Antimicrobial resistance is one of the world's most pressing public health problems. The worldwide use and misuse of antimicrobials in medicine and agriculture have resulted in the selection of bacteria resistant to the microbiologic activity of these agents. These resistant bacteria fail to respond to treatment, resulting in prolonged hospitalizations,(More)