Microbiological profile of a shipboard environment and the flora on contact lenses of seamen.
PURPOSE: The purpose of this study was to culture and identify the spectrum of organisms (and their sensitivities) that contaminate the extended wear contact lenses of seamen in their working environment. A secondary aim was to identify the most appropriate first-line antibiotic regimen to be used on seamen who sustain contact lens-related corneal keratitis on board ship. METHODS: Twenty pairs of contact lenses of 20 seamen in one group and 24 pairs in another group wearing contact lenses were collected at the end of 1 week of extended wear. Groups one and two differed only in the way lenses were stored prior to culturing. All contact lenses were then brought to the microbiological lab within 24 hours for culture and sensitivity testing. RESULTS: The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids. Enterobacterand Pseudomonas species, present in a shipboard environment, were also identified as contaminants on the contact lenses. The organisms cultured from the contact lenses correlated well with those of normal lid flora as well as from the ship environment and are probably derived from these sources. Storage in saline-containing preservatives yielded significantly less positive bacterial cultures from the contact lenses in our study. All bacterial isolates were sensitive to ciprofloxacin whereas several bacteria resistant to cefazolin and gentamicin were identified. CONCLUSION: The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids. Enterobacter and Pseudomonas species, which are normally present in a shipboard environment, were also identified as contaminants on the contact lenses. Ciprofloxacin is effective against all organisms identified as contaminants on the contact lenses in this study. Of all the antibiotics tested, it is probably the most suitable agent against contact lensrelated keratitis under such shipboard circumstances and is thus recommended in these situations.