Korean J healthc assoc Infect Control Prev.  2023 Jun;28(1):143-154. 10.14192/kjicp.2023.28.1.143.

Difficult-to-treat Acinetobacter Bacteremia in Hospital Acquired Pneumonia Patients, South Korea, 2016-2019

• Kim S
• Kim D
• Lee EH
• Song JE
• Hyun J

• KMID: 2543145
• DOI: http://doi.org/10.14192/kjicp.2023.28.1.143

Abstract

Background
Difficult-to-treat resistance (DTR) Acinetobacter infection has emerged as a worldwide concern and causes substantial morbidity and mortality. This study aimed to evaluate the patterns of antimicrobial resistance (AMR) and analyze risk factors for mortality in patients with highly resistant Acinetobacter infections.
Methods
We retrospectively evaluated 231 patients with Acinetobacter bacteremia caused by pneumonia between January 2016 and December 2019. We compared clinical characteristics and outcomes between non-survivor and survivor groups, identified AMR patterns through resistance categories and antimicrobial agents, and analyzed the risk factors for 28-day mortality.
Results
We retrospectively evaluated 231 patients with Acinetobacter bacteremia caused by pneumonia between January 2016 and December 2019. We compared clinical characteristics and outcomes between non-survivor and survivor groups, identified AMR patterns through resistance categories and antimicrobial agents, and analyzed the risk factors for 28-day mortality.
Conclusion
DTR was associated with higher mortality in Acinetobacter species bacteremia caused by pneumonia. In cases without optimal treatment strategies, colistin may be considered as a treatment option to improve clinical outcomes in DTR Acinetobacter infections.

Keyword

Acinetobacter; Bacteremia; Drug resistance; Healthcare-associated pneumonia; Mortality

Figure

• 

  Fig. 1 Flow chart of the study population. Abbreviations: MDR, multidrug-resistant; XDR, extensively drug-resistant; DTR, difficult-to-treat resistance; CR, carbapenem-resistant.

• 

  Fig. 2 Diagram showing the relationship between MDR, XDR, DTR and PDR. Abbreviations: DTR, difficult-to-treat resistance; MDR, multidrug-resistant; PDR, pandrug-resistant; XDR, extensively drug-resistant.

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  Fig. 3 Antimicrobial resistance among 231 clinical isolates of the Acinetobacter species. (A) Prevalence of antimicrobial resistance phenotypes. (B) Trends in antimicrobial resistance phenotypes among Acinetobacter species, 2016-2019. (C) Drug susceptibility results for each antimicrobial agent. Abbreviations: AMK, amikacin; ATM, aztreonam; CAZ, ceftazidime; CIP, ciprofloxacin; CR, carbapenem-resistant; CST, colistin; DTR, difficult-to-treat resistance; ECR, extended-spectrum cephalosporin-resistant; FEP, cefepime; FQR, fluoroquinolone-resistant; GEN, gentamicin; IPM, imipenem/cilastatin; LVX, levofloxacin; MDR, multidrug-resistant; MEM, meropenem; MIN, minocycline; N/A, not available; SAM, ampicillin-sulbactam; TGC, tigecycline; TMP/SMX, trimethoprim-sulfamethoxazole; TZP, piperacillin-tazobactam; XDR, extensively drug-resistant.

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  Fig. 4 Kaplan–Meier survival curves of (A) DTR and Non-DTR, (B) MDR and Non-MDR, (C) CR and non-CR, and (D) colistin-containing regimen and regimen without colistin in the DTR group. Abbreviations: DTR, difficult-to-treat resistance; MDR, multi-drug resistant; CR, carbapenem-resistant; CST, colistin; CPM, carbapenem.

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