Clinical Characteristics and Outcomes of Bloodstream Infections Caused by Metallo-β-Lactamase–Producing Enterobacterales in Argentina: A Subanalysis of the EMBARCAR Prospective Multicenter Cohort Study

Abstract Background Bloodstream infections (BSI) caused by metallo-beta-lactamase (MBL)-producing Enterobacterales (E) are associated with high mortality. However, in most Latin American countries there is a lack of clinical and microbiological data on BSI caused by MBL-E. Methods This preplanned subgroup analysis of the multicenter, observational, prospective EMBARCAR study focused on adult patients with BSI caused by MBL-E in Argentina. Logistic regression adjusted by propensity scores (PS) for the treatment with ceftazidime-avibactam plus aztreonam (CAZ/AVI plus ATM) were used to identify variables associated with mortality. Results A total of 140 patients with BSI caused by MBL-producing Enterobacterales were included. Median age was 59 years (IQR 46–70), and most patients were male (61%). Most frequent comorbidities were diabetes 23%, class III obesity 19%, and chronic renal failure 19%. Two thirds of patients were hospitalized in critical care units, 60% required mechanical ventilation and 38% presented with shock. Most frequent isolated microorganisms were Klebsiella pneumoniae (75%) and Serratia marcescens (12%). Most patients (64%) received combination therapy and 23% received CAZ/AVI plus ATM. Thirty-day mortality was 41%. In the multivariate PS adjusted analysis, INCREMENT-CPE score ≥8 was associated with increased risk of mortality (odds ratio [OR] 3.63; 95% CI: 1.13, 11.7), while CAZ/AVI plus ATM therapy with a lower risk of death (OR 0.18; 95% CI: .05, .58). Conclusions In summary, BSI due to MBL-producing Enterobacterales resulted in a high mortality rate in our country. The use of CAZ/AVI plus ATM was associated with a decreased mortality. Better access to these antibiotics should be granted.