Identification of Chlamydia, Legionella and Mycoplasma genomic signatures among patients with Microbial Keratitis

Abstract

Purpose : The prevalence and diversity of intracellular pathogens such as Chlamydia trachomatis, Legionella pneumophila, and Mycoplasma pneumoniae among patients presenting with bacteria keratitis in contact-lens associated keratitis is unknown. This is due in part to the lack of clinical suspicion and the requirement for special media, tissue culture and or molecular techniques for confirmation.
Purpose: to determine the frequency and diversity of chlamydia, legionella and mycoplasma DNA signatures among patients presenting with contact lens associated keratitis

Methods : We used whole genomic sequencing to document the presence of Chlamydia Legionella and Mycoplasma bacterial signatures among 28 contact lens/cases from 14 patients presenting with microbial keratitis within the most recent 10 years.

Results : Relative abundance for the group was less than 1% (20,350 hits of 3 or more for each species). The respiratory associated Mycoplasma species were the predominantly identified bacterial signatures among this group. Genomic signatures included Mycoplasma hypopneumoniae (67.6%, 10,879 tags, in 28/28 samples and 14/14 patients), Mycoplasma hyorhinis (16.7%, 2685 tags, in 22/28, 78.6% of samples and in 13/14, 92.8% of patients) and Mycoplasma pulmonis (15.5%, 2499 tags, in 24/28, 85.7% of samples and in all 13 patients). All were more likely to be recovered from culture and acanthamoeba positive samples and from the infected corneas. Chlamydia trachomatis and Chlamydia psittaci signatures were present in 17.4% (3544) of the tags. C. trachomatis (95.7%, 3392, 3 samples and 2 patients) was more likely to be recovered from the infected eye of culture negative patients. C. psittaci (2.8%, 101, 11 patients) were more likely to be associated with culture and acanthamoeba positive samples and the infected eye. Legionella genomic signatures were present in 4.1% (844) of the tags and included Legionella pneumophila (73.2%, 618, 16 samples and 10 patients) and Legionella longbeachae (2.8%, 101, 14 samples and 8 patients). Both were more likely to be detected in culture and acanthamoeba samples and the noninfected eye.

Conclusions : Intracellular pathogens and or atypical microorganisms may be present in contact lens cases more frequently than reported. This may have implications for the epidemiology and management of contact lens associated keratitis.

This is a 2020 ARVO Annual Meeting abstract.