AETIOLOGIC AGENTS OF ACUTE OTITIS MEDIA (AOM): PREVALENCE, ANTIBIOTIC SUSCEPTIBILITY, β-LACTAMASE (βL) AND EXTENDED SPECTRUM β-LACTAMASE (ESBL) PRODUCTION

Abstract

Two hundred and seventy-two samples from patients with acute otitis media attending Ear, Nose and Throat clinics in Uyo and Ikot Ekpene were collected using sterile swab sticks between January 2009 and December, 2010. In vitro antibiotic susceptibilities of the isolates were evaluated using Kirby-Bauer technique. Beta-lactamase and extended spectrum beta-lactamase producers were determined using starch paper test, chromogenic cephalosporin test and double disc synergy test, respectively. The highest prevalence of AOM was observed in age group ≤ 10 years with 84 (30.9%) cases and lowest prevalence observed in age group ≤ 61 having 12 (4.4%) cases with significant difference in the prevalence of AOM between age groups ≤ 10 years and other age groups at (P<0.5). One hundred and sixtyfive samples showed growth of single isolates, 69 (25.4%) showed growth of two isolates and polybacterial growth was present in 29 (10.7%). Bacteria isolated were Staphylococcus aureus, Pseudomonas aureginosa, Proteus mirabilis, Streptococcus pneumoniae, Coagulase negative Staphylococcus spp., Klebsiella pneumoniae, Escherichia coli, Proteus vulgaris, Streptococcus pyogenes and Bacteriodes fragilis. The isolates were highly sensitive to moxifloxacin and levofloxacin. The starch paper test identified 152 (38.2%) β-lactamase producers, while β-lactamase enzyme was detected in 163 (41.0%) of isolates through chromogenic cephalosporin test, with no statistical difference at P˃0.5 between the results obtained using the two methods. Thirty-three (33) of the 81 Gram negative bacilli were ESBL producers. Consequently, this study has updated data on the incidence of the AOM and also revealed the actual therapy.