Ocular Microbiology and Immunology Group
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2017 OMIG Abstract 26

Prevalence of Acanthamoeba Giant Viruses Among Patients with Microbial Keratitis
Ibrahim Osama Sayed-Ahmed MD, Jorge Maestre, PHD, Maria Del Carmen Piqueras, BS,
Sanjoy K Bhattacharya, PHD, Eduardo Alfonso, MD, Darlene Miller DHSC, MPH, CIC
Bascom Palmer Eye Institute, Miami, Florida

Purpose: Acanthamoeba polyphagia Mimiviruses and other giant viruses are ubiquitous in nature. Free living amoebas serve as hosts and potential dissemination vectors. Although reported from a contact lens case of a patient with amoebic keratitis in 2011, they have also been recovered from other human samples since their discovery (respiratory secretions, feces, and blood). Their pathology, frequency, and diversity are still unknown. Our purpose was to investigate the frequency, abundance, and diversity of giant viruses in patients presenting with microbial keratitis.

Methods: Samples from a total of 11 patients were screened for giant viruses by three methods. Mass spectrometry was used to determine quantity and diversity of proteins associated with 5 giant virus families in 5 contaminated contact lens cases (CTL) of 5 patients and cultured microbial hosts from the cornea of 3 patients presenting with both cornea (K) positive (n=5) and negative (n=3) microbial keratitis. Viral identification was determined using a blast searches of NCBI giant virus proteins. PCR (n=6) with subsequent sequencing of expanded primers (GENEWIZ Inc., Plainfield, NJ) as well as whole genome sequencing (n=4) (CosmosID, Rockville, MD) were also performed.

Results: A total 2288 proteins from 5 different viral families (Mimiviridae (38%, n=869), Phycodnaviridae (32.5% n=743), Pandoraviridae (20.4% n=467), Marseilleviridae (7%, n=164) and Pithioviruses (2%, n=45) were found among our samples. The frequency of giant virus proteins found in all 8 samples was Mimiviridae (89.5%), Pandoraviridae (88.3%), Marseille viruses (87%), Pithoviruses (86.2%) and Phycodnaviruses (98.4%).  Of the 11 samples, 6 were positive for Mimivirus DNA by PCR and were sent for sequencing revealing sequences for several Mimivirus strains. Whole genome sequencing (n=4) revealed 3 samples positive for Panoravirus dulcis, two of which were also positive for Mollivirus sibericum.

Conclusions: We confirmed a high prevalence and diversity of giant viruses in contaminated contact lens cases and Acanthamoeba hosts cultured from corneas of patients presenting with microbial keratitis. Pathogenicity and their role in microbial keratitis has yet to be determined.

Disclosure: N

Grant support: NIH core Grant P30-EY 14801, Research to Prevent Blindness.

2017 Agenda and Abstracts | < Previous Next >