Streptococcus pneumoniae-induced ototoxicity in organ of Corti explant cultures.

Streptococcus pneumoniae-induced ototoxicity in organ of Corti explant cultures.
Hear Res. 2017 Apr 25;350:100-109
Authors: Perny M, Solyga M, Grandgirard D, Roccio M, Leib SL, Senn P
Abstract
Hearing loss remains the most common long-term complication of pneumococcal meningitis (PM) reported in up to 30% of survivors. Streptococcus pneumoniae have been shown to possess different ototoxic properties. Here we present a novel ex vivo experimental setup to examine in detail the pattern of hair cell loss upon exposure to different S. pneumoniae strains, therefore recapitulating pathogen derived aspects of PM-induced hearing loss. Our results show a higher susceptibility towards S. pneumoniae-induced cochlear damage for outer hair cells (OHC) compared to inner hair cells (IHC), which is consistent with in vivo data. S. pneumoniae-induced hair cell loss was both time and dose-dependent. Moreover, we have found significant differences in the level of cell damage between tissue from the basal and the apical turns. This shows that the higher vulnerability of hair cells located at high frequency regions observed in vivo cannot be explained solely by the spatial organisation and bacterial infiltration from the basal portion of the cochlea. Using a wild type D39 strain and a mutant defective for the pneumolysin (PLY) gene, we also have shown that the toxin PLY is an important factor involved in ototoxic damages. The obtained results indica...

Source: Hearing Research - April 25, 2017 Category: Audiology Authors: Perny M, Solyga M, Grandgirard D, Roccio M, Leib SL, Senn P Tags: Hear Res Source Type: research