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. 2025 Oct 17;19(2 Suppl):1-14.
doi: 10.21010/Ajidv19i2S.1. eCollection 2025.

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

Vuai Miza Silima  1   2 , Kumburu Happiness Houka  3   4 , Mkumbaye Sixbert Isdory  3   5 , Kajeguka Debora Charles  3 , Kavishe Reginald Adolph  1
Affiliations

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

Vuai Miza Silima et al. Afr J Infect Dis. .

Abstract

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.

Keywords: Antimicrobial; COVID-19; and Gram- negative bacteria; resistance.

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Conflict of interest statement

The authors declare that there is no conflicts of interest associated with this study. List of Abbreviations:AMR:Antimicrobial resistance;AST:Antimicrobial susceptibility test, COVID-19: Coronavirus disease 2019;DDS:double disk synergy;ESBL:Extended-spectrum beta-lactamase;KCMC:Kilimanjaro Christian Medical Center;KCRI:Kilimanjaro Clinical Research Institute;WHO:World health organization;WGS:Whole Genome Sequencing

Figures

Figure 1
Figure 1
Overall antibiotic resistance rate in both study periods, before and During the COVID 19 era; * indicates p ≤ 0.05, ** indicates p ≤ 0.01.
Figure 2A
Figure 2A
Trends in antimicrobial resistance of Escherichia coli in 2018, 2020, and 2023. AMP =Ampicillin, GEN= Gentamicin, CIP= ciprofloxacin, TZP= piperacillin-tazobactam, MEP= meropenem, CAZ = ceftazidime, CRO=ceftriaxone, SXT= trimethoprim-sulfamethoxazole, AK= amikacin, TE= tetracycline, C =Chloramphenicol, FOX=cefoxitin, AMC= amoxicillin clavulanic acid. Escherichia coli showed statistically difference in resistance to CRO, p=0.021.
Figure 2B
Figure 2B
Trends in antimicrobial resistance of Klebsiella pneumoniae in 2018, 2020, and 2023. AMP =Ampicillin, GEN= Gentamicin, CIP= ciprofloxacin, TZP= piperacillin-tazobactam, MEP= meropenem, CAZ = ceftazidime, CRO=ceftriaxone, SXT= trimethoprim-sulfamethoxazole, AK= amikacin, TE= tetracycline, C = Chloramphenicol, FOX=cefoxitin, AMC= amoxicillin clavulanic acid. Klebsiella pneumonia showed statistically significant difference in resistance to SXT, p=0.02, AMC, p=0.02 and C, p=0.015.
Figure 2C
Figure 2C
Trends in antimicrobial resistance of Acinetobacter spp. in 2018, 2020, and 2023. GEN= Gentamicin, CIP= ciprofloxacin, TZP=piperacillin-tazobactam, MEP= meropenem, CAZ = ceftazidime, CRO=ceftriaxone, SXT= trimethoprim-sulfamethoxazole, TE= tetracycline. Acinetobacter spp. showed statistically significant differences in CIP (p = 0.022) and CAZ (p = 0.023) resistance.
Figure 2D
Figure 2D
Trends in antimicrobial resistance of Pseudomonas spp. in 2018, 2020, and 2023. GEN= Gentamicin, CIP= ciprofloxacin, TZP= piperacillin-tazobactam, MEP= meropenem, CAZ = ceftazidime, Pseudomonas spp. showed statistically difference in resistance to CIP, p=0.016.
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