Bacteriological Profile and Antibiotic Susceptibility Pattern in Surgically Treated Complicated Cases of Mastoiditis: A Retrospective Cohort

Abstract

Background: Mastoiditis is a serious complication of the AOM. The treatment of mastoiditis is mainly conservative and the surgical interventions are reserved only for the life-threatening complications. However, the empirical treatment regimen is failing to treat mastoiditis in recent times and a rise in recurrent and resistant cases has been observed. Antibiotic resistance against the causative bacterial strains is the suspected cause of ineffective medical treatment.

Objective: The purpose of this study is to improve the medical treatment of mastoiditis by identifying the causative organisms and their antibiotic susceptibility pattern in children with acute/chronic mastoiditis and associated complications who had a history of failed conservative treatment and underwent inevitable surgical procedures.

Study Design: A Retrospective Cohort Study of the preoperatively collected samples of pus culture and sensitivity reports of 56 children with complicated mastoiditis, surgically treated at Children Hospital and Institute of Child Health, Lahore, from May 2021 – June 2022.

Results: The most frequent pathogens were Proteus spp. (Mirabilis) (n=16, 29%), Pseudomonas Aeruginosa (n=12, 21%), and Staphylococcus Aureus (n=11, 19.6%). The intravenous antibiotics found to be the most sensitive against mastoiditis bacteria (in descending order) were Tanzobactam-Piperacillin (n=49, 88%), Sulbactam-Cefoperazone (n=48, 86%), Vancomycin (n=45, 80%), and Clarithromycin (n=43, 77%). Whereas the empirical oral antibiotic treatment were ineffective for more than 50% of the cases, based on the drug susceptibility results.

Conclusion: The emergence of resistance in bacterial strains responsible for mastoiditis was found to be the main cause of failed conservative treatment and development of recurrent, persistent, and/or complicated mastoiditis.