Risk factors for acquisition and mortality of multidrug-resistant Acinetobacter baumannii bacteremia

Abstract

Bloodstream infection caused by Acinetobacter baumannii has become a major clinical concern, especially multidrug-resistant A baumannii (MDRAB). The aim of this study was to identify the risk factors of nosocomial acquired MDRAB bacteremia and to determine the risk factors related to the mortality of patients with MDRAB bacteremia. Patients with nosocomial acquired A baumannii bacteremia were enrolled between January, 2013 and December, 2017 at the First Affiliated Hospital, School of Medicine, Zhejiang University. Medical records were reviewed, and the clinical and microbial characteristics were collected. Among the 338 patients suffering from A baumannii bacteremia, 274 patients were infected with MDRAB bacteremia. Bacteremia-related mortality was 46.4% for the overall sample; 56.2% for MDRAB bacteremia patients, 4.7% for non-MDRAB bacteremia patients. The identified risk factors for developing MDRAB bacteremia were previous exposure to carbapenems [odds ratio (OR) 5.78, P = .005] and penicillins+β-lactamase inhibitors (OR 4.29, P = .009). Primary bacteremia tended to develop non-MDR bacteremia (OR 0.10, P = .002). The risk factors for MDRAB bacteremia-related mortality were old age (OR 1.02, P = .036), a high Pitt bacteremia score (OR 1.32, P < .001), bacteremia occurring after severe pneumonia (OR 8.66, P < .001), while catheter-related infection (OR 0.47, P = .049) and operations for treating infection (OR 0.51, P = .043) may have a better outcome. Patients with MDRAB had a higher mortality rate. Patients with previous carbapenems and penicillins+β-lactamase inhibitor exposure are at an increased risk of MDRAB bacteremia, whereas patients with primary bacteremia tended to develop non-MDR bacteremia. The risk factors for MDRAB bacteremia-related mortality were old age, a high Pitt bacteremia score, and bacteremia occurring after severe pneumonia, whereas catheter-related infection and operations for the treatment of infection may have a better outcome.

Bloodstream infections caused by ST2 Acinetobacter baumannii&nbsp;over 6 years in China: risk factors, antibiotic regimens and virulence

“…The use of mechanical ventilation, ICU stay and thrombocytopenia may cause higher mortality. Previous studies demonstrated that the mortality risk factors associated with poor prognosis include older age, severity of the underlying disease, septic shock, a high Pitt bacteremia score, previous surgery, mechanical ventilation, and inappropriate antimicrobial treatment [12,[22][23]. The ICU was the highest risk unit of this nosocomial outbreak of MDR-AB, which could subsequently disseminate within the hospital [24].…”

Bloodstream infections&nbsp;caused by ST2 Acinetobacter baumannii: Risk factors, antibiotic regimens, and virulence over 6 years period in China

“…The use of mechanical ventilation, ICU stay, and thrombocytopenia have all been associated with higher mortality. Previous studies demonstrated that the mortality risk factors associated with poor prognosis include older age, the severity of the underlying disease, septic shock, a high Pitt bacteremia score, previous surgery, mechanical ventilation, and inappropriate antimicrobial treatment [21,42,43]. The ICU has been identi ed as the unit at the highest risk of the nosocomial outbreak of MDR-AB [44].…”

“…High resistance and virulence of bacteria are the main factors associated with high mortality in patients with bloodstream infections [10,21]. Some studies reported that the patient's condition, previous exposure to antimicrobial (especially broad-spectrum antibiotics), previous colonization with A. baumannii, increased Pitt bacteremia score, being in the intensive care unit (ICU), and recent invasive procedures are risk factors associated with MDR acquisition in A. baumannii bloodstream infection [22][23][24].…”

The Outer Membrane Proteins OmpA, CarO, and OprD of Acinetobacter baumannii Confer a Two-Pronged Defense in Facilitating Its Success as a Potent Human Pathogen

“…The potency of A. baumannii as a successful pathogen can be elaborated by the high number of deaths associated with its infection. A recent finding showed that bacteremia caused by multidrug-resistant (MDR) A. baumannii exhibited 56.2% mortality rate among infected patients ( Zhou et al, 2019 ).…”