Culture and Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) Proven Mycobacterium Tuberculosis Endophthalmitis: A Case Series

ABSTRACT

Purpose: To report early confirmation of Mycobacterium tuberculosis (MTB) endophthalmitis by detection of 85B mRNA in vitreous by a reverse transcriptase polymerase chain reaction (RT-PCR) technique.

Methods: Retrospective, interventional case series of 5 patients with MTB endogenous endophthalmitis. Vitreous aspirate was subjected to Ziehl-Neelsen (ZN) staining, BACTEC MicroMGIT culture, RT-PCR targeting the 85B gene, real-time PCR targeting the IS6110 region, and nested PCR targeting the MPB64 gene and IS6110 region. Correlation between detection of MTB RNA, culture positivity, and ZN staining was studied.

Results: Five patients with endophthalmitis with no history of tuberculosis revealed acid-fast bacilli on ZN staining of vitreous. RT-PCR detected 85B RNA within 24 h. Culture for MTB was positive in 3/5 patients after 1 month. None of the eyes recovered any useful vision.

Conclusions: RT-PCR can detect viable MTB RNA and provide evidence of active infection much earlier than culture.

Keywords:

• Acid fast bacilli
• endophthalmitis
• Mycobacterium tuberculosis
• RT-PCR
• vitrectomy

ACKNOWLEDGEMENTS

We thank the Vitreoretina Department and Microbiology Department at Sankara Nethralaya, Chennai.

DECLARATION OF INTEREST

The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.