Methicillin‐resistant Staphylococcus aureus in acute otitis externa

Abstract

ObjectiveOtologic methicillin-resistant Staphylococcus aureus (MRSA) infection has historically been rare, but given the rise in community-acquired MRSA carriage and infection at other body sites, prevalence rates may be changing. The goal of this study was to determine the prevalence of MRSA in recent otologic cultures from patients with acute otitis externa (AOE).Study designRetrospective review of an institutional microbiologic database.MethodsA retrospective analysis was performed on serial culture isolates taken from the ear at a quaternary care hospital from January 2014 to April 2016. The causative pathogen and antibiotic sensitivity was determined by culture isolation and end point mean inhibitory concentration (MIC) testing. Medical records were reviewed to document patient characteristics, chronicity of infection, symptomatology, and previous treatments.ResultsOver the study period, 173 patients were diagnosed with AOE and underwent otologic cultures of the ear. Fifty-three (30.6%) of cultures grew S.aureus (SA). Of SA infections, 15 (28.3%) were identified as MRSA. MRSA patients were typically older than patients with methicillin-sensitive SA (MSSA) (mean age 46.7 ± 17.9 vs 29 ± 19.4, P = 0.003) and had more medical comorbidities (4 vs 1.7, P = 0.001). Compared to patients with MSSA, patients with MRSA were significantly more likely to have had prior ototopical antibiotic exposure (37% vs 73%, P = 0.019).ConclusionContemporary ear culture isolates at quaternary care center show higher rates of MRSA compared to historical reports in the literature. Clinicians should consider ear cultures to identify MRSA AOE.Level of EvidenceIV.

Bacteriological Flora of Acute Otitis Externa

“…Empirical use of antibiotics may have imposed selective pressure that eventually changed the external ear microbial flora. 22 An alarming rate of MRSA was isolated at our center which has been reflected in the study by Duarte et al 22 Initially nosocomial in nature, an increase in communityacquired MRSA has surged in otological infections over the years. This may reflect the increasing prevalence of carriage and infection rates of MRSA in the community.…”

Short Communication: Otitis externa in a tertiary care hospital in Zagazig, Egypt: Isolated pathogens and their antibiotic sensitivity patterns

“…The issue of bacterial resistance to antibiotics is a global challenge (15). In developed countries such as the United States, contemporary ear culture isolates at quaternary care center show higher rates of methicillin resistant S. aureus (MRSA) compared to historical reports in the literature (16). However, the challenge of antibiotic resistance is more in developing countries such as Egypt (17), as a result of low socioeconomic state and behavioral pattern of the populace regarding antibiotic use (18).…”

Community Acquired MRSA from Head and Neck Space Infections

“…In 2002, Hwang et al, (3) reported >8.5% increase in CA-MRSA incidence in ear infections in Taiwan. Similarly, in 2007 a group from Hawaii noted a rapid increase in CA-MRSA head and neck infections from 21% to 64% over a five-year period.…”