IgM mediated cefotaxime resistance of Streptococcus pneumoniae is linked to hearing loss in adult acute otitis media.

OBJECTIVE

To investigate cefotaxime resistance in Streptococcus pneumoniae among adult acute otitis media (AOM) patients, its association with hearing loss, and the mediating role of immunoglobulin M (IgM).

METHODS

A retrospective cohort study was conducted, enrolling 188 adult AOM patients treated between January 2018 and December 2023. Streptococcus pneumoniae infection was confirmed via bacterial culture of ear secretions, and cefotaxime susceptibility was tested using the disc diffusion method. Hearing loss was diagnosed based on World Health Organization (WHO) criteria using tympanometry and pure tone audiometry. Univariate and multivariate logistic regression analyses were performed to assess the correlation between cefotaxime resistance and hearing loss. Spearman correlation analysis evaluated their association, and mediation analysis using Bootstrap method (5,000 resamples) was applied to examine the mediating effect of IgM.

RESULTS

Cefotaxime resistance was significantly positively correlated with hearing loss (r = 0.25, P < 0.001). The hearing loss group exhibited higher prevalence of diabetes history, tympanic effusion, chronic ear disease history, and cefotaxime resistance (P < 0.05). IgM levels were significantly lower in the hearing loss group (P < 0.001) and partially mediated the association between cefotaxime resistance and hearing loss (P = 0.033), accounting for 26.9% of the total effect. Multivariate analysis identified time from symptom onset to admission, tympanic effusion, chronic ear disease history, cefotaxime resistance, and IgM levels as independent predictors of hearing loss (all P < 0.05).

CONCLUSION

Cefotaxime resistance is associated with an increased risk of hearing loss in adult AOM patients, with IgM partially mediating this relationship. Early identification of resistant strains and IgM monitoring may improve outcomes.