Antibiotic Resistance Among Ocular Pathogens in the United States: Five-Year Results From the Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) Surveillance Study.

Importance: The Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) study is the only ongoing nationwide antibiotic resistance surveillance program specific to ocular pathogens.

Objective: To report resistance rates and trends among common ocular isolates collected during the first 5 years of the ARMOR study.

Design, Setting, And Participants: This antibiotic resistance surveillance study was performed at an independent central laboratory.

Activities of carbapenem and comparator agents against contemporary US Pseudomonas aeruginosa isolates from the CAPITAL surveillance program.

Antimicrobial susceptibilities of contemporary Pseudomonas aeruginosa clinical isolates were determined from the CAPITAL 2010 surveillance program. Isolates were collected from 100 sites throughout the USA and Puerto Rico, and included isolates representing a range of patient demographics and infection types. A total of 2722 isolates were tested for susceptibility to a broad spectrum of agents, with susceptibilities ranging from 98.

Enterococcus faecalis senses target cells and in response expresses cytolysin.

Many virulent strains of Enterococcus faecalis produce a two-subunit toxin, termed cytolysin. Cytolysin expression is regulated by one of the subunits (CylL(S)'') through a quorum-sensing autoinduction mechanism. We found that when target cells are absent, the other subunit (CylL(L)'') forms a complex with CylL(S)'', blocking it from autoinducing the operon.

Enterococcal virulence--pathogenicity island of E. Faecalis.

Enterococcal species, though most commonly regarded as members of the microbial flora of the intestinal tract, have recently emerged as human pathogens of significant concern. The rapid spread of antibiotic resistance among enterococci, which has resulted in strains now being routinely isolated that are resistant to all bactericidal regimens, has prompted considerable interest in investigating the pathogenesis of enterococcal infection, with a view toward deriving new, information-based treatment strategies. This review summarizes major findings on the pathogenesis of enterococcal infection, fits them into a model for the dual lifestyle of enterococci as commensal and pathogen, and integrates into that model a recently discovered pathogenicity island of Enterococcus faecalis.

Pseudomonas aeruginosa exotoxin A and keratitis in mice.

Purpose: To determine the importance of Pseudomonas aeruginosa exotoxin A (ETA) as a virulence factor in corneal disease.

Methods: Isogenic mutants deficient in ETA were constructed in P. aeruginosa strains PAO1 and ATCC 19660 by allelic exchange and then evaluated for virulence in a mouse model of bacterial keratitis.