Frequency, Types and Antimicrobial Susceptibility Pattern of Bacteria in Culture Positive Ear Swabs of Patients Attending Referral Hospital in Southern Zone of Tanzania

Abstract

Background: Ear infections affect adults and children, and when left untreated, they may cause hearing loss and lifethreatening complications. In our setting, ear infections are a common health problem. However, there is paucity of information on the etiology and antimicrobial susceptibility pattern.Objective: This study aimed to determine the spectrum of bacteria causing ear infection and their antimicrobial susceptibility patterns at Secondary-level health facilities. Methods: This cross sectional retrospective hospital-based study reviewed 288 data of patients diagnosed with ear infections from January 2021 to March 2023. Demographic, isolates and antimicrobial susceptibility information's were abstracted. Multidrug resistance (MDR) was regarded as resistance to at least one antibiotic in three or more categories/ groups of antibiotics. Analysis was done using STATA software version 15. Descriptive analysis was summarized as frequency and proportion for categorical variables, and results presented using tables. Results: We included 288 (50.4%) positive bacteria culture out of ear swab samples collected for culture in the analysis. Of the total bacterial isolates, majority were gram-negative, 178 (58.2%). The predominant isolate was Staphylococcus aureus 124 (40.5%), followed by Pseudomonas aeruginosa 80 (26.1%). Mixed bacterial infection was observed in 18 (6.2%) patients. Most enterobacterales were resistant to ampicillin, amoxicillin/clavulanic acid, tetracycline and trimethoprim-sulfamethoxazole. Pseudomonas aeruginosa was highly resistant to piperacillin. Multidrug resistance (MDR) was observed in 245 (80%) of the isolates. Gram positive isolates showed high resistance to erythromycin. Methicillinresistant Staphylococcus aureus (MRSA) was observed in 67(59.3%) isolated Staphylococcus aureus. Conclusion: Staphylococcus aureus and Pseudomonas aeruginosa were the predominant isolates in ear infections. Most of the bacteria were resistant to commonly used antibiotics. Multidrug resistance and MRSA were highly observed. Therefore, an antibiotic susceptibility test is important to guide antibiotic prescription practice. BACKGROUNDA n ear infection is a common problem for adults and children 1 . Ear infections include Acute Otitis Media (AOM), Chronic Suppurative Otitis Media (CSOM) and otitis externa (OE). 2 An ear infection is a major public health concern and when left untreated, may cause hearing loss, deafness, life-threatening complications and mortality. 3 In resource limited settings, most patients with ear infections delay seeking medical attention; hence, usually present with complications. 4 About 65-330 million people suffer from ear infection worldwide, and 60% report hearing impairment. 2 The highest rate of ear infection was reported from Sub-Saharan Africa and South Asia 5 . In Tanzania, the magnitude of ear infections was 53.3%. 6 Peer Reviewed Acknowledgement: Authors would like to thank the Management of St. Benedict Ndanda Referral Hospital for their approval to conduct this study. We would al...