Detection of Bacterial Etiological Agents, Antibiotic Susceptibility and Associated Risk Factors from Patients with Ear Infections at St. Paul ,s Hospital Millennium Medical College

Abstract

Abstract Background Ear infection refers to inflammation of the ear and represents a significant health problem affecting both adults and children. Ear discharge is among the most common clinical manifestations of ear infections. Otitis media, in particular, is a leading cause of healthcare visits and antibiotic prescriptions. Its complications and long-term sequelae constitute major, yet preventable, causes of hearing loss, especially in developing countries. In resource-limited settings, antibiotic therapy is frequently prescribed empirically without guidance from culture and antibiotic susceptibility testing (AST). Consequently, inappropriate use and overuse of antimicrobial agents contribute to the emergence and spread of antimicrobial resistance. Therefore, identifying the predominant bacterial etiologies of ear infections, determining their antimicrobial susceptibility patterns, and assessing associated risk factors are essential for mitigating the multidimensional impact of ear diseases. Objective: Detection of Bacterial Etiological Agents, Antibiotic Susceptibility and Associated Risk Factors from Patients with Ear Infections at St. Paul’s Hospital Millennium Medical College. Method: A prospective cross-sectional study was conducted at St. Paul , s Hospital Millennium Medical College Ear, Nose and Throat Outpatient department. Information with regard to risk factors and clinical characterstics was gathered by well-structured pre tested questionnaire and ear swab samples were collected from all 224 participants by attending physician, nurse and the investigator (laboratory technologist). The samples were cultured on MacConkey agar, Blood agar and chocolate agar simultaneously. Positive growths were sub cultured and biochemical test were performed with standard microbiological technique. Quality control and standard operating procedures were followed for quality and reliability of the result. The data was entered into Excel sheet and analyzed using SPSS version 27 software computer packages. Descriptive statistics, including frequency, mean and percentages, was computed. To analyze the risk factors, univariable and multivariable logistic regression models was employed. A P-value of less than 0.05 was considered statistically significant. Results: - Of 224 ear discharge samples, Bacterial culture positivity rate was 126(56.3%) of which 31(13.85%) were with mixed isolates and 95(42.45%) with single isolate. So there was a total of 157 bacterial isolate from 31 mixed bacteria which is 62 isolate and 95 single isolate . Out of a total of 157 bacterial isolate, 122(77.7%) were gram negative bacteria and 35(22.3%) gram positive bacterial isolates. The predominant bacterial etiological agents detected were Staphylococcus aureus 30(19.1%), Pseudomonas species 24(15.3%), Klebsiella oxytoca 20(12.7%), Citrobactor species 17(10.8%) and E.coli 16(10.2%). Fungal elements of 8(3.6%) was observed microscopically from gram stain. The most Effective antibiotics for GPB was Cefoxitin, Gentamycin and Trimetoprime Sulphamethoxazole and resistant to Macrolide class (erythromycin), Tetracycline’s class, Lincomycin class (clindamycin) and Ciprofloxacin. The most Effective antibiotics for GNB was Carbapenems class (meropenem), Cephalosporin class (cefepime and ceftazidim), Aminoglycosides class (Gentamycin and amikacin) and Fluoroquinolones class (Ciprofloxacin) and resistant to Penicillin’s class (Ampicillin and Augmentin ) and Tetracycline’s class (Tetracycline). Among the socio demographic factors and clinical characterstics, Age group, number of rooms that the patient reside and and history of head trauma was significantly associated with bacterial ear. Overall MDR rate among ear discharge bacterial isolates was 52(33.1%) of which 35(28.70%) were GNB and 17(48.60%) GPB. Conclusion:- S.aureus , Pseudomonas species, Klebsiella oxytoca ,Citrobactor species and E.coli were the leading cause of ear infection. Most of the ear discharge isolate were resistant to antibiotics classes of Penicilline, Tetracycline, Macrolide and Lincomycin class. However, the antibiotics like Aminoglycosides, cephalosporins, Fluoroquinolones, and Carbapenems were the most effective in treating ear discharge bacterial isolates. These result help as a baseline for effective treatment and guide the empirical treatment. Age group, history of head trauma and small number of room was significantly associated with ear infection. Identification of these specific risk factors will adds a public health relevance. The presence of high rate resistant strains calls for periodic and continuous follow-up of antimicrobial drug susceptibility testing and update of empirical treatment guidelines. Key Words: Otitis Media, Antimicrobial resistance, Multidrug resistance and Risk factors.