PHENOTYPIC ANTIBIOTIC RESISTANCE PROFILES OF GRAM-NEGATIVE BACTERIA IN CLINICAL SAMPLES PRE AND DURING COVID-19 PANDEMIC AT ZONAL REFERRAL HOSPITAL NORTHERN TANZANIA

Background: COVID-19 has aggravated antimicrobial use owing to limited treatment options, raising concerns about antimicrobial resistance, which was previously estimated to potentially cause 10 million global deaths within 30 years. This study evaluated the potential impact of the COVID-19 pandemic on antibiotic resistance in referral hospitals. Material and Methods: A cross-sectional study at Kilimanjaro Christian Medical Centre analyzed clinical bacterial samples from pre-COVID-19 (2018) and during COVID-19 (2020, 2023). Two hundred isolates from 2018 and 2020, and 121 samples from 2023, were examined. Bacterial isolates were identified using API 20E for Enterobacteriaceae (bioMérieux) and standard biochemical tests, while antimicrobial susceptibility was assessed using the disc diffusion method. Results: During the COVID-19 pandemic, antibiotic resistance among bacteria has increased significantly. Resistance to ampicillin 113 (95.8%, p=0.018), ceftriaxone 102 (74.5%, p=0.043), and ciprofloxacin 119 (68.8%, p=0.003) increased. Conversely, resistance to chloramphenicol 19 (16.1%, p=0.021) and amoxicillin-clavulanic acid decreased to 62 (52.5 %, p = 0.007). Klebsiella pneumoniae showed decreased resistance to chloramphenicol 11(20.8%, p=0.004) and amoxicillin-clavulanic acid 27(50.9%, p=0.034). Acinetobacter species also showed a significant increase in ceftriaxone resistance 18(94.7%, p=0.018). Among the 233 isolates, ESBL-producing bacteria were identified in 101 (43.4%), and Klebsiella pneumoniae and Escherichia coli showed the highest frequencies at 40 (39.6%) and 54 (53.5%), respectively. Conclusion: During COVID-19, ampicillin, ciprofloxacin, and ceftriaxone resistance significantly increased, whereas restricted antibiotics, such as meropenem, showed lower resistance. The extensive and uncontrolled use of antibiotics during the pandemic has aggravated antimicrobial resistance, necessitating intensified and coordinated efforts to combat it.