IOSR Journal of Pharmacy and Biological Sciences (IOSR-JPBS) e-ISSN: 2278-3008, p-ISSN:2319-7676. Volume 10, Issue 6 Ver. I (Nov - Dec. 2015), PP 01-05 www.iosrjournals.org DOI: 10.9790/3008-10610105 www.iosrjournals.org 1 | Page Study of Bacterial Isolates and their Susceptibility Pattern in Chronic Suppurative Otitis Media Zina Bakir Al-Hilli Department of Microbiology/ College of Veterinary Medicine/ Al-Qasim Green University, Iraq Abstract: Chronic Suppurative Otitis Media (CSOM) is one of the common ear diseases which can cause many complications if not treated properly . This study was done to determine isolates causing CSOM and their antibiotic susceptibility pattern. The study was carried out from November 2014 to April 2015. Ear swabs were collected & cultured from one hundred and twenty patients with CSOM attending the ENT Out Patient Clinic in Al- Hillah Teaching hospital. The specimens were cultured The isolated organisms were identified by standard microbiological methods. The antibiotic susceptibility testing of the isolates was done using the Kirby-Bauer disc diffusion method.CSOM was less common among elderly and women. Pseudomonas aeruginosa was the most common isolated bacteria (37.5%) followed by Staphylococcus aureus (20.83%), and Streptococcus pneumoniae (16.67%).The most effective antibiotics in this study were ciprofloxacin and ceftazidime , whereas the highest resistance levels were observed for trimethoprim, carbenicillin, lincomycin and erythromycin. Keywords: Chronic suppurative otitis media, Pseudomonas aeruginosa, Staphylococcus aureus, antibiotic susceptibility. I. Introduction Otitis media is an inflammation of the middle ear that affects the tympanic membrane [1]. It is a disease of multiple etiology and pathogenesis of otitis media are multifactorial including genetic predisposition, infections, allergy, environmental, social and racial factors and eustachian tube dysfunction [2]. There are three common types of otitis media, acute purulent otitis media, otitis media with effusion and chronic suppurative otitis media [3]. Chronic Suppurative Otitis Media (CSOM) is a chronic inflammation of middle ear and mastoid cavity that may present with recurrent ear discharges or otorrhoea through a tympanic perforation [4]. It is one of the most common diseases of all age groups, especially of childhood and is prevalent in developing countries [5]. The common micro organisms most frequently isolated in CSOM cases are Pseudomonas aeruginosa, Staphylococcus aureus, Proteus mirabilis, Klebsiella spp, Escherichia coli, Aspergillus spp. and Candida spp. but these organisms vary in various geographical areas [4]. The bacteria are uncommon in the skin of the external canal, but in the presence of inflammation, trauma, lacerations or high humidity may proliferate [6]. These bacteria may then gain an entry to the middle ear through a chronic perforation [7]. However, antimicrobial resistance profile of bacteria causing CSOM has been reported to vary with time because of differences in geographical areas as well as from continent to another probably due to indiscriminate use of the antibiotics [8 , 9]. This study performed to evaluate the prevalence of bacterial agents in cases of CSOM and their antibiogram pattern to provide a guideline for empirical antibiotic therapy. II. Materials And Methods In this study one hundred and twenty patients of CSOM who presented to the Ear, Nose, and Throat (ENT) Out Patient Clinic in Al- Hillah Teaching Hospital from November 2014 to April 2015 were included. Only patients who had not received topical or systemic antibiotics for the previous 5 days were included in the study. A total of 120 swabs were collected using sterile cotton swabs and transferred immediately to the laboratory by brain heart infusion broth. Ear discharge samples were cultured on Nutrient agar, MacConkey agar and Blood agar plates and then incubated aerobically at 37 ºC for 24 hours. All the isolated organisms were identified according to standard microbiological methods [10]. Antimicrobial susceptibility tests of bacterial isolates were carried out using Kirby- Bauer disk diffusion method on Mueller-Hinton agar medium (Himedia, India) [11]. The tested antimicrobial agents were: L: Lincomycin (2 μg), PY: Carbenicillin (100 μg), E: Erythrymycin (15 μg), AMC: Amoxi -clav (30 μg), CAZ: Ceftazidime (30 μg), CRO: Ceftriaxone (30 μg), TMP: Trimethoprim (25 μg), CN: Gentamycin (10 μg), TOB: Tobramycin (10 μg), CIP: Ciprofloxacin (5 μg) (Bioanalyse, Turkey). The antibiotic disc impregnated culture plates were incubated at 37 ºC overnight. Results were interpreted according to the National Committee for Clinical Laboratory Standards [12].