Fourteen phylogenetically diverse 17beta-estradiol-degrading bacteria (strains KC1-14) were isolated from activated sludge of a wastewater treatment plant. These isolates widely distributed among eight different genera--Aminobacter (strains KC6 and KC7), Brevundimonas (strain KC12), Escherichia (strain KC13), Flavobacterium (strain KC1), Microbacterium (strain KC5), Nocardioides (strain KC3), Rhodococcus (strain KC4), and Sphingomonas (strains KC8-KC11 and KC14)--of three Phyla: Proteobacteria, Actinobacteria, and Bacteroidetes. All 14 isolates were capable of converting 17beta-estradiol to estrone, but only three strains (strains KC6, KC7, and KC8) showed the ability to degrade estrone. Only strain KC8 could use 17beta-estradiol as a sole carbon source. Based on the degree of estrogens being transformed and the estrogenicity of metabolites and/ or end products of estrogen degradation, three different degradation patterns (patterns A-C) were observed from degradation tests using resting cells. Eleven out of 14 isolates showed degradation pattern A, where 17beta-estradiol was stoichiometrically converted to estrone. Estrone was confirmed to be a degradation product of 17beta-estradiol; however, estrone was not further degraded during the course of experiments. Strains KC6 and KC7 exhibited degradation pattern B, where both 17beta-estradiol and estrone were degraded, with slower 17beta-estradiol degradation rates than those observed in pattern A. Strain KC8 was the only strain exhibited degradation pattern C, where 17beta-estradiol and estrone were rapidly degraded within 3 days. No residual 17beta-estradiol and estrone or estrogenic activity was detected after 5 days, suggesting that strain KC8 could degrade 17beta-estradiol into nonestrogenic metabolites/end products. Strains KC6-8 exhibited nonspecific monooxygenase activity but not nonspecific dioxygenase activity. However, the relationship between nonspecific monooxygenase activity and its estrogen degradation ability was unclear.

PURPOSE To determine if clinical and reference strains of Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus aureus form biofilms on silicone hydrogel contact lenses, and ascertain antimicrobial activities of contact lens care solutions. METHODS Clinical and American Type Culture Collection (ATCC) reference strains of Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus aureus were incubated with lotrafilcon A lenses under conditions that facilitate biofilm formation. Biofilms were quantified by quantitative culturing (colony forming units, CFUs), and gross morphology and architecture were evaluated using scanning electron microscopy (SEM) and confocal microscopy. Susceptibilities of the planktonic and biofilm growth phases of the bacteria to five common multipurpose contact lens care solutions and one hydrogen peroxide care solution were assessed. RESULTS P. aeruginosa, S. marcescens, and S. aureus reference and clinical strains formed biofilms on lotrafilcon A silicone hydrogel contact lenses, as dense networks of cells arranged in multiple layers with visible extracellular matrix. The biofilms were resistant to commonly used biguanide preserved multipurpose care solutions. P. aeruginosa and S. aureus biofilms were susceptible to a hydrogen peroxide and a polyquaternium preserved care solution, whereas S. marcescens biofilm was resistant to a polyquaternium preserved care solution but susceptible to hydrogen peroxide disinfection. In contrast, the planktonic forms were always susceptible. CONCLUSIONS P. aeruginosa, S. marcescens, and S. aureus form biofilms on lotrafilcon A contact lenses, which in contrast to planktonic cells, are resistant to the antimicrobial activity of several soft contact lens care products.