Molecular characterization, biofilm analysis and experimental biofouling study of Fusarium isolates from recent cases of fungal keratitis in New York State.
BACKGROUND
To characterize Fusarium isolates from recent cases of fungal keratitis in contact lens wearers, and to investigate fungal association with MoistureLoc solution.


METHODS
We studied six fungal isolates from recent cases of keratitis in New York State. The isolates were characterized by nucleotide sequencing and phylogenetic analyses of multiple genes, and then typed using minisatellite and microsatellite probes. Experimental fungal biofilm formation was tested by standard methods. MoistureLoc solutions were tested in biofouling studies for their efficacy in elimination of Fusarium contamination.


RESULTS
Fusarium solani--corneal ulcers (2 isolates), lens case (1 isolate), and F. oxysporum--corneal ulcer (1 isolate), eye (1 isolate), were recovered from five patients. An opened bottle of MoistureLoc solution provided by a patient also yielded F. solani. Two distinct genotypes of F. solani as well as of F. oxysporum were present in the isolated strains. Remarkably, F. solani strains from the lens case and lens solution in one instance were similar, based on phylogenetic analyses and molecular typing. The solution isolate of F. solani formed biofilm on contact lenses in control conditions, but not when co-incubated with MoistureLoc solution. Both freshly opened and 3-month old MoistureLoc solutions effectively killed F. solani and F. oxysporum, when fungal contamination was simulated under recommended lens treatment regimen (4-hr). However, simulation of inappropriate use (15-60 min) led to the recovery of less than 1% of original inoculum of F. solani or F. oxysporum.


CONCLUSIONS
Temporary survival of F. solani and F. oxysporum in MoistureLoc suggested that improper lens cleaning regimen could be a possible contributing factor in recent infections.
Dyavaiah
Madhu
M
Mycology Laboratory, Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, Albany, NY 12208-2002, USA. madhud14@yahoo.co.in
Ramani
Rama
R
Chu
David S
DS
Ritterband
David C
DC
Shah
Mahendra K
MK
Samsonoff
William A
WA
Chaturvedi
Sudha
S
Chaturvedi
Vishnu
V
D018441:Biofilms; D018639:Contact Lens Solutions / Q000494:pharmacology; D003261:Contact Lenses / Q000009:adverse effects* / Q000382:microbiology*; D003320:Corneal Ulcer / Q000382:microbiology; D004340:Drug Contamination; D015821:Eye Infections, Fungal / Q000209:etiology*; D005670:Fusarium / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D007634:Keratitis / Q000382:microbiology*; D009518:New York; D013997:Time Factors
D018639:Contact Lens Solutions