Bacterial isolates and antibiotic resistance in critically ill sepsis patients at a tertiary hospital in Ethiopia

Abstract

Background: Sepsis is a pressing global public health issue, particularly among patients admitted to intensive care unit (ICU), and it is linked to a high incidence of morbidity and mortality. Current understanding of bacterial profiles, antibiotic resistance patterns, and the magnitude of Extended-Spectrum Beta-Lactamase (ESBL) and Carbapenemase (CP) producing isolates in critically ill patients is vital for implementing strong management approaches tailored to combat antibiotic resistance and improve patient outcomes.

Methods: A prospective cross-sectional study was carried out involving 149 patients admitted to ICU with a presumptive diagnosis of sepsis at Jimma University Medical Center (JUMC) from October 2023 to October 2024. A structured questionnaire was administered to collect baseline demographic and clinical characteristics of the patients. Blood samples were aseptically collected and analyzed using standard microbiological technique to identify bacterial isolates. The Kirby-Bauer disc diffusion method was employed to conduct the antimicrobial susceptibility test. The MASTDISCS^® Combi AmpC and ESBL detection discs D68 C, and Combi Carba plus disc system D73C were used to examine ESBL and CP production, respectively.

Results: Bacterial pathogens were isolated from 33 patients, representing an isolation rate of 22.1% (95% CI: 16.2-29.6%). Gram-negative bacteria (GNB) accounted for the majority of the isolates, 25/33 (75.8%), with Escherichia coli, 6/25 (24%) being the predominant species. Administering antibiotics before sample collection was associated with a lower likelihood of culture positivity (AOR: 0.05, 95% CI: 0.01-0.38; p = 0.004). In contrast, prolonged stay in the ICU was positively associated with culture positivity (AOR: 1.13, 95% CI:1.02-1.24; p = 0.02). Gram-negative bacteria exhibited a particularly high resistance to third- and fourth-generation cephalosporins, ranging from 66.7 to 80%. ESBL and CP producers accounted for 11/25 (44%) and 12/25(48%) of GNB, respectively. Additionally, 80% of Staphylococcus aureus isolates were methicillin resistant. Overall, about a third of all isolates, 11/33 (33.3%) were multidrug resistant strains.

Conclusions: The study shows a significant burden of MDR pathogens among critically ill sepsis patients, characterized by high prevalence of ESBL, CP, and MRSA. These findings underscore the urgent need to strengthen antibiotic stewardship and infection prevention strategies to curb resistance in ICU environments.

Clinical trial number: Not applicable.

Keywords: Antimicrobial resistance; Bacterial isolates; Critically ill; Ethiopia; Sepsis.

Fig. 1

The distribution of bacterial profile among ICU admitted patients with sepsis

Fig. 2

Antimicrobial resistance rates of gram-negative bacteria. AMC: Amoxicillin + clavulanic acid, AMK: Amikacin, AMP: Ampicillin, C: Chloramphenicol, CN: Gentamicin, CAZ: Ceftazidime, CEP: Cefepime, CIP: Ciprofloxacin, CTX: Cefotaxime, FAM: Ampicillin + Sulbactam, MEM: Meropenem, SXT: Trimethoprim/sulfamethoxazole, TZP: Piperacillin + tazobactam

Fig. 3

Antimicrobial resistance rates of gram-positive bacteria. CN: Gentamicin, PEN: Penicillin G, OX: Oxacillin, VAN: Vancomycin

Fig. 4

Antimicrobial resistance rates of ESBL, CP, non-ESBL, and non-CP producers