Paenibacillus lautus: A new foe in endogenous endophthalmitis.

Abstract

Purpose: To discuss the diagnosis and management of a rare case of endogenous endophthalmitis (EE) caused by Paenibacillus lautus mimicking granulomatous uveitis in a child, highlighting the use of 16S rRNA gene amplicon sequencing as an accurate method to identify rare pathogens.

Method: A retrospective chart review of the clinical presentation, microbiologic workup-including microscopy, culture, antibiotic susceptibility, and polymerase chain reaction for pathogen DNA of clinical samples-and the clinical management of the case were recorded.

Result: A 13-year-old boy presented with decreased vision in the right eye for one month. On examination, he had uveitis with hypopyon and complicated cataract. The case underwent an anterior chamber tap followed by vitrectomy and lensectomy. The culture of the vitreous aspirate grew Gram-variable bacilli that could not be identified by conventional microbiological techniques. However, PCR-based sequencing of the 16S rRNA gene was performed, and the bacterium was identified as P. lautus. The patient subsequently developed rhegmatogenous retinal detachment, for which he underwent endo laser photocoagulation and oil tamponade. Four months later, silicone oil was removed, and an intraocular lens was implanted. At six weeks follow-up, the retina remained well attached, and intraocular pressure was maintained.

Conclusion: P. lautus can cause EE and mimic granulomatous uveitis. Techniques such as 16S rRNA gene sequencing can significantly facilitate aetiological diagnosis in cases where conventional methods fail.