Penicillin-resistant pneumococci in middle ear isolates : an emerging problem

Abstract EN

Objective : To investigate the frequency of penicillin-resistant pneumococci in middle ear infections.

Methods : The present study was conducted on 65 ear isolates of pneumococci from adult patients (age 18-48 years) over a 23-month period from January 1995 to December 1996 at King Hussein Medical Center.

Kirby-Bauer disc diffusion and agar dilution E-test minimal inhibitory concentration (MIC) methods determined susceptibility.

Results : The prevalence of intermediately penicillin-resistant strains (MIC 0.12-1.0pig / ml) was 22 %, whereas the prevalence of highly resistant strains (MIC > 2pg / ml) was 3 %.

Multiple resistance (resistance to three or more antibacterial agents) was 13 %.

Twenty isolates were resistant to Erythromycin and Clindamycin.

Against all isolates tested, Imipenem, Ceftriaxone, and Clarthromycin had the greatest activity (MIC : 0.12, 0.25, 0.5fjg / ml, respectively).

Conclusion : There was a high prevalence of penicillin-resistant pneumococci assessed by MIC determination by E-test in our isolates.

This should be taken into consideration to reduce the consequences of multidrug-resistant pneumococcal infections including persistent purulent otitis media, increasing usage of broad-spectrum antibiotics and recurrence.