Título

VISUAL PROGNOSIS BASED ON RAPID IDENTIFICATION OF ETIOLOGIC AGENT BY MALDI-TOF OF INFECTIOUS ENDOPHTHALMITIS

Objetivo

To analyze the visual outcome of infectious endophthalmitis based on the etiologic agent identified by MALDI-TOF.

Método

This prospective study included 37 patients with clinical suspicion of infectious endophthalmitis attended in a tertiary university hospital in São Paulo, Brazil, from October 2015 to June 2017. Vitreous humor samples were inoculated in pediatric blood culture bottles (BCBs). Positive BCBs were either seeded in culture plates and then submitted to MALDI-TOF (standard procedure) or were directly submitted to MALDI-TOF after a simple in-house protein extraction protocol (direct MALDI-TOF MS). The microorganisms’ ID and turnaround time (TAT) by standard and direct MALDI-TOF analysis were determined and compared (student t test). Visual acuity at 3 months after diagnosis was analysed based on the etiologic agent identified. This study was approved by Institutional Ethics Committee and followed the Helsinki declaration.

Resultado

The median TATs for pathogen ID by standard procedure and direct MALDI-TOF MS analysis were 50.6 h (28.9 h-187.5 h) and 14.4 h (3.1 h - 94.0 h), respectively (p <0.0001). ID by direct MALDI-TOF was as faster as 3.1h for microrganism with high virulence, e.g. S. marcencens; for less virulent agent, such as S. epidermidis, ID by direct MALDI-TOF was less than 24 hours. Visual acuity better than 20/200 at the 3rd month was observed in 72.7% (8 out 11) of patients with S. epidermidis. Endophthalmitis caused by Gram negative agents, S. aureus and S. pneumoniae had poor visual prognosis.

Conclusão

Rapid diagnosis for pathogens in infectious endophthalmitis can be obtained within 24 hours or less with direct pathogen ID of vitreous humor-inoculated BCBs by MALDI-TOF MS. The rapid acknowledgment by the ophthalmologist of more virulent agent may impact on treatment strategy and visual prognosis.