Bacterial biofilm on contact lenses and lens storage cases in wearers with microbial keratitis

Abstract

Bacterial biofilm formation on contact lenses (CLs), and CL storage cases may be a risk factor for CL-associated corneal infection and may explain the persistence of organisms in CL storage cases. This study evaluated biofilm formation on, and microbial contamination of, CLs and CL storage cases from patients with microbial keratitis. Contact lenses and CL storage cases from 20 wearers with microbial keratitis were sampled microbiologically and visualized using scanning electron microscopy (SEM). Culture results from the cornea were also noted. Bacterial biofilm was present more frequently (P < 0.05) on CL storage case surfaces (17/20) compared with CL surfaces (11/20) and biofilm density was significantly greater on case surfaces (P < 0.05). There was no association between poor compliance and microbial contamination of the CL storage case, nor between poor compliance and biofilm formation or density on the CL or CL storage case. Biofilm formation occurred equally frequently with hydrogen peroxide and chlorine release care systems. Microbial keratitis in CL wearers is frequently associated with bacterial biofilm in the CL storage case. Despite the use of current CL disinfection systems, the CL storage case is a favourable environment for proliferation of certain organisms. Biofilm on CLs may prolong the retention time of organisms at the ocular surface and increase their potential pathogenicity.

Avaliação da ação antimicrobiana de soluções multiuso para desinfecção de lentes de contato hidrofílicas, in vitro

“…Com relação ao biofilme, estudos mostraram que a sua formação nos estojos para LC influencia a contaminação e nova formação de biofilme nas LC (9,28) . O biofilme é mais resistente aos agentes antimicrobianos, dificultando a completa remoção dos microrganismos, como foi observado neste trabalho.…”

“…O contato de microrganismos com a superfície ocular, por meio da LC ou da solução contida no estojo contaminado, contribui para o desenvolvimento de infecção (9) . Estudos mostram que grande parte das contaminações das LC ocorre após o contato com as mãos dos usuários (10)(11) .…”

Microbial Biofilms: from Ecology to Molecular Genetics

“…Millions of catheters (e.g., central line, intravenous, and urinary catheters) are inserted into patients every year, and these implants serve as a potential surface for biofilm formation. Biofilm formation can also occur on contact lenses, and these biofilms are thought to contribute to keratitis (69,88,162). Overall, it is thought that upwards of 60% of all nosocomial infections are due to biofilms.…”

Microbial Adhesion in Flow Displacement Systems

“…Adhesion to and detachment of bacteria from contact lenses plays an important role in the development of infectious keratitis, where biofilms formed in contact lens casings provide a continuous source of microorganisms (32,54). Cleansing of contact lens surfaces is facilitated through the use of lens care solutions to remove adsorbed tear film components and to kill and detach possible adhering bacteria (20).…”