scholarly journals Susceptibility of various corneal fungal isolates and Pseudomonas aeruginosa to contact lens disinfecting solutions

2013 ◽  
Vol 7 (03) ◽  
pp. 261-268 ◽  
Author(s):  
Antonio Pinna ◽  
Donatella Usai ◽  
Stefania Zanetti ◽  
Philip A Thomas ◽  
Jayaraman Kaliamurthy
Keyword(s):  
Hydrogen Peroxide ◽  
Pseudomonas Aeruginosa ◽  
Contact Lens ◽  
Luria Bertani ◽  
Sabouraud Agar ◽  
Fungal Strains ◽  
Soft Contact Lens ◽  
Fungal Isolates ◽  
Colony Forming Units ◽  
Care Systems

Introduction: We aimed to investigate the susceptibility of a combined inoculum of Pseudomonas aeruginosa and different fungal strains to 6 soft contact lens disinfectants. Methodology: One corneal isolate of P. aeruginosa and 13 corneal fungal isolates (9 Aspergillus spp, 3 Fusarium spp, 1 Curvularia sp.) were used. The following solutions were tested: Arion Cronos, Complete RevitaLens, Dua Elite, Opti-Free Express, Regard, Oxysept Comfort, and Oxysept Comfort without catalase. The effect of the solutions was assessed on a combined inoculum of P. aeruginosa plus 1 fungal strain. Suspensions of P. aeruginosa and fungi were made in the solutions (1x106 colony-forming units/mL). After 1 hour (Arion Cronos only), 6, 8, and 24 hours, aliquots of suspension were removed and seeded on Luria-Bertani and Sabouraud agar plates. Results: After 6 hours’ exposure, all the solutions but Dua Elite and Oxysept Comfort eradicated P. aeruginosa. Conversely, apart from 3% hydrogen peroxide-based Oxysept Comfort without catalase, which eradicated all the fungi tested after 6 hours, all the other solutions were partly ineffective at killing some of the fungal isolates, even after 24 hours’ exposure. Conclusions: Most contact lens disinfectants may be ineffective if contact lens care systems become co-contaminated with P. aeruginosa and fungi. In our experiment, only exposure to 3% hydrogen peroxide without neutralizer for at least 6 hours was always able to kill a combined inoculum of P. aeruginosa and different fungal strains.

scholarly journals Enhanced Killing of Acanthamoeba Cysts with a Plant Peroxidase-Hydrogen Peroxide-Halide Antimicrobial System

2003 ◽  
Vol 69 (5) ◽  
pp. 2563-2567 ◽  
Author(s):  
Reanne Hughes ◽  
Peter W. Andrew ◽  
Simon Kilvington
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Contact Lens ◽  
Acanthamoeba Keratitis ◽  
Free Living ◽  
Soybean Peroxidase ◽  
Plant Peroxidase ◽  
Time Points ◽  
Free Living Amoeba ◽  
Care Systems

ABSTRACT The activity of H2O2 against the resistant cyst stage of the pathogenic free-living amoeba Acanthamoeba was enhanced by the addition of KI and either horseradish peroxidase or soybean peroxidase or, to a lesser degree, lactoperoxidase. This resulted in an increase in the cysticidal activity of 3% (wt/vol) H2O2, and there was >3-log killing in 2 h, compared with the 6 h required for comparable results with the peroxide solution alone (P < 0.05). With 2% H2O2, enhancement was observed at all time points (P < 0.05), and total killing of the cyst inoculum occurred at 4 h, compared with 6 h for the peroxide alone. The activity of sublethal 1% H2O2 was enhanced to give 3-log killing after 8 h of exposure (P < 0.05). No enhancement was obtained when KCl or catalase was used as a substitute in the reaction mixtures. The H2O2 was not neutralized in the enhanced system during the experiments. However, in the presence of a platinum disk used to neutralize H2O2 in contact lens care systems, the enhanced 2% H2O2 system gave 2.8-log killing after 6 h or total cyst killing by 8 h, and total neutralization of the H2O2 occurred by 4 h. In contrast, 2% H2O2 alone resulted in <0.8-log killing of cysts in the presence of the platinum disk due to rapid (<1 h) neutralization of the peroxide. Our observations could result in significant improvement in the efficacy of H2O2 contact lens disinfection systems against Acanthamoeba cysts and prevention of acanthamoeba keratitis.

Antimicrobial Effectiveness of Some Soft Contact Lens Care Systems

1987 ◽  
Vol 64 (11) ◽  
pp. 824-828 ◽  
Author(s):  
LINDA S. Y. TSE ◽  
MURCHISON G. CALLENDER ◽  
A. MICHAEL CHARLES
Keyword(s):  
Contact Lens ◽  
Soft Contact ◽  
Soft Contact Lens ◽  
Care Systems ◽  
Antimicrobial Effectiveness

COMFORT, PATIENT ACCEPTANCE AND SYMPTOMATOLOGY WITH TWO SOFT CONTACT LENS CARE SYSTEMS.

2001 ◽  
Vol 78 (SUPPLEMENT) ◽  
pp. 313
Author(s):  
Michel Guillon ◽  
Cecile Maissa ◽  
Philip Cooper ◽  
Karine Girard-Claudon
Keyword(s):  
Contact Lens ◽  
Patient Acceptance ◽  
Soft Contact ◽  
Soft Contact Lens ◽  
Care Systems

scholarly journals Serum-Associated Antibiotic Tolerance in Pediatric Clinical Isolates of Pseudomonas aeruginosa

2019 ◽  
Author(s):  
John M Morrison ◽  
Michaelle Chojnacki ◽  
Jeffrey J Fadrowski ◽  
Colleen Bauza ◽  
Paul M Dunman ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Human Serum ◽  
A Priori ◽  
Luria Bertani ◽  
Future Research ◽  
Hospitalized Children ◽  
Antibiotic Tolerance ◽  
Patient Demographics ◽  
Intravenous Antibiotics ◽  
Colony Forming Units

Abstract Background When grown in human serum, laboratory isolates of Pseudomonas aeruginosa exhibit tolerance to antibiotics at inhibitory concentrations. This phenomenon, known as serum-associated antibiotic tolerance (SAT), could lead to clinical treatment failure of pseudomonal infections. Our purpose in this study was to determine the prevalence and clinical impact of SAT in Pseudomonas isolates in hospitalized children. Methods The SAT phenotype was assessed in patients aged &lt;18 years admitted with respiratory or blood cultures positive for P. aeruginosa. The SAT phenotype was a priori defined as a ≥2-log increase in colony-forming units when grown in human serum compared with Luria-Bertani medium in the presence of minocycline or tobramycin. Results SAT was detected in 29 (64%) patients. Fourteen patients each (34%) had cystic fibrosis (CF) and tracheostomies. Patient demographics and comorbidities did not differ by SAT status. Among CF patients, SAT was associated with longer duration of intravenous antibiotics (10 days vs 5 days; P &lt; .01). Conclusions This study establishes that SAT exists in P. aeruginosa from human serum and may be a novel factor that contributes to differences in clinical outcomes. Future research should investigate the mechanisms that contribute to SAT in order to identify novel targets for adjunctive antimicrobial therapies.

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