الملخص الإنجليزي
Background: Bloodstream infections caused by carbapenem-resistant Gram-negative bacteria represent a major
therapeutic challenge to clinicians worldwide. This study examined the epidemiology of carbapenem and colistin
resistance in Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii blood
isolates in an academic institution in Oman.
Methods: Adult patients with bloodstream infections caused by Klebsiella pneumoniae, Escherichia coli, Pseudomonas
aeruginosa, and Acinetobacter baumannii, between January 1, 2017, and December 31, 2020, were identified. Rates
of carbapenem resistance, carbapenem-colistin dual resistance, and 30-day all-cause mortality were examined.
Results: 585 non-repeat bloodstream infections due to Klebsiella pneumoniae, Escherichia coli, Pseudomonas aerug inosa, and Acinetobacter baumannii were identified during the study period. OXA-48 was the most prevalent car bapenemase gene in carbapenem-resistant K. pneumoniae blood isolates. Carbapenem resistance was observed in
160 (27.7%) of blood isolates, with 131 (81.9%) of these being healthcare-onset cases. Carbapenem resistance
was highest in Acinetobacter baumannii (80.4%), followed by Klebsiella pneumoniae (46.4%), and Pseudomonas
aeruginosa (29.9%). Sixteen (13.4%) of the carbapenem-resistant blood isolates were found to be colistin resistant.
Thirty-day all-cause mortality was 68.1% in patients with bloodstream infections caused by carbapenem-resistant
isolates, versus 21.3% in patients with bloodstream infections caused by carbapenem-susceptible isolates.
Conclusion: The prevalence of carbapenem resistance and carbapenem-colistin dual resistance in Gram-negative
blood culture isolates from patients with bloodstream infections is unacceptably high. Patients with bloodstream
infections due to carbapenem-resistant isolates had substantially higher mortality.
