Clinical and Microbiological Analysis of Risk Factors for Mortality in Patients with Carbapenem-Resistant Enterobacteriaceae Bacteremia.

The aims of this study were to identify whether the site of acquisition or the underlying carbapenem-resistant Enterobacteriaceae (CRE) resistance mechanism was associated with clinical outcomes, and to evaluate risk factors for 14-day mortality in patients with CRE bacteremia. A retrospective cohort study was conducted at a 2700-bed tertiary center. All adult patients with monomicrobial carbapenem-resistant Escherichia coli or Klebsiella pneumoniae bacteremia from 2011 to 2018 were included. All blood isolates collected were tested with a modified carbapenem inactivation method for phenotypic detection of carbapenemase. Of 133 patients with monomicrobial CRE bacteremia, 63 (47.4%) were infected with carbapenemase-producing CRE (CP-CRE), and 70 (52.6%) with non-CP-CRE. Patients with community-onset infection (COI) were more likely to present with biliary or urinary tract infections, less likely to have ineradicable or non-eradicated foci and to receive appropriate empirical therapy, and marginally more likely to have CP-CRE compared with those with hospital-acquired infection (HAI). However, 14-day mortality was significantly lower in COI than HAI (7% vs 29%, P = 0.01). Patients who died were more likely to have had a higher APACHE II score, ineradicable or non-eradicated foci, and a lower chance of having received appropriate antibiotic treatment. Multivariate analysis revealed that HAI, high APACHE II score, and inappropriate antibiotic treatment were independent risk factors for mortality. Carbapenemase production did not affect mortality. The results of this study indicate that timely, appropriate treatment is essential for managing CRE bacteremia, regardless of carbapenemase production, particularly in critically ill patients with hospital-acquired bacteremia.

Seo H ，Lee SC ，Chung H ，Ra SH ，Sung H ，Kim MN ，Jung J ，Kim MJ ，Kim SH ，Lee SO ，Choi SH ，Kim YS ，Woo JH ，Chong YP ... -  《-》

Epidemiology of Carbapenem-Resistant Enterobacteriaceae Infections: Report from the China CRE Network.

Carbapenem-resistant Enterobacteriaceae (CRE) infection is highly endemic in China, but estimates of the infection burden are lacking. We established the incidence of CRE infection from a multicenter study that covered 25 tertiary hospitals in 14 provinces. CRE cases defined as carbapenem-nonsusceptible Citrobacter freundii, Escherichia coli, Enterobacter cloacae, or Klebsiella pneumoniae infections during January to December 2015 were collected and reviewed from medical records. Antimicrobial susceptibility testing and carbapenemase gene identification were performed. Among 664 CRE cases, most were caused by K. pneumoniae (73.9%), followed by E. coli (16.6%) and E. cloacae (7.1%). The overall CRE infection incidence per 10,000 discharges was 4.0 and differed significantly by region, with the highest in Jiangsu (14.97) and the lowest in Qinghai (0.34). Underlying comorbidities were found in 83.8% of patients; the median patient age was 62 years (range, 45 to 74 years), and 450 (67.8%) patients were male. Lower respiratory tract infections (65.4%) were the most common, followed by urinary tract infection (16.6%), intra-abdominal infection (7.7%), and bacteremia (7.7%). The overall hospital mortality rate was 33.5%. All isolates showed nonsusceptibility to carbapenems and cephalosporins. The susceptibility rate of polymyxin B was >90%. Tigecycline demonstrated a higher susceptibility rate against E. coli than against K. pneumoniae (90.9% versus 40.2%). Of 155 clinical isolates analyzed, 89% produced carbapenemases, with a majority of isolates producing KPC (50%) or NDM (33.5%)-type beta-lactamases among K. pneumoniae and E. coli The incidence of CRE infection in China was 4.0 per 10,000 discharges. The patient-based disease burden in tertiary hospitals in China is severe, suggesting an urgent need to enhance infection control.

Zhang Y ，Wang Q ，Yin Y ，Chen H ，Jin L ，Gu B ，Xie L ，Yang C ，Ma X ，Li H ，Li W ，Zhang X ，Liao K ，Man S ，Wang S ，Wen H ，Li B ，Guo Z ，Tian J ，Pei F ，Liu L ，Zhang L ，Zou C ，Hu T ，Cai J ，Yang H ，Huang J ，Jia X ，Huang W ，Cao B ，Wang H ... -  《-》

Appropriate non-carbapenems are not inferior to carbapenems as initial empirical therapy for bacteremia caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae: a propensity score weighted multicenter cohort study.

Ko JH ，Lee NR ，Joo EJ ，Moon SY ，Choi JK ，Park DA ，Peck KR ... -  《-》

Comparing the Outcomes of Patients With Carbapenemase-Producing and Non-Carbapenemase-Producing Carbapenem-Resistant Enterobacteriaceae Bacteremia.

Carbapenem-resistant Enterobacteriaceae (CRE) are associated with considerable mortality. As mechanisms of carbapenem resistance are heterogeneous, it is unclear if mortality differs based on resistance mechanisms. We sought to determine whether CRE resistance mechanism determination is prognostically informative. We conducted an observational study comparing 14-day mortality between patients with carbapenemase-producing (CP)-CRE compared with non-CP-CRE bacteremia. Clinical data were collected on all patients. A comprehensive DNA microarray-based assay was performed on all isolates to identify β-lactamase-encoding genes. There were 83 unique episodes of monomicrobial CRE bacteremia during the study period: 37 (45%) CP-CRE and 46 (55%) non-CP-CRE. The majority of CP-CRE isolates were bla KPC (92%), followed by bla NDM (5%) and bla OXA-48-type (3%). CP-CRE isolates were more likely to have meropenem minimum inhibitory concentrations (MICs) ≥16 µg/mL, while non-CP-CRE isolates were more likely to have meropenem MICs ≤1 µg/mL (P value < .001). A total of 18 (22%) patients died within 14 days, including 12 (32%) in the CP-CRE group and 6 (13%) in the non-CP-CRE group. Adjusting for severity of illness on day 1 of bacteremia, underlying medical conditions, and differences in antibiotic treatment administered, the odds of dying within 14 days were more than 4 times greater for CP-CRE compared with non-CP-CRE bacteremic patients (adjusted odds ratio, 4.92; 95% confidence interval, 1.01-24.81). Our findings suggest that CP-CRE may be more virulent than non-CP-CRE and are associated with poorer outcomes. This underscores the added importance of delineating underlying resistance mechanisms of CRE to direct antibiotic treatment decisions.

Tamma PD ，Goodman KE ，Harris AD ，Tekle T ，Roberts A ，Taiwo A ，Simner PJ ... -  《-》

Comparing mortality in patients with carbapenemase-producing carbapenem resistant Enterobacterales and non-carbapenemase-producing carbapenem resistant Enterobacterales bacteremia.

Carbapenem-resistant Enterobacterales (CRE) are classified as either carbapenemase-producing CRE (CP-CRE) or non-carbapenemase-producing CRE (non-CP-CRE) based on their mechanism of carbapenem resistance. Few studies have compared outcomes associated with each type of infection. We attempted to determine if either CRE subset is associated with increased mortality. We performed a retrospective observational study to collect demographic, clinical and outcomes data to compare patients with CP-CRE and non-CP-CRE bacteremia. Of 146 cases analyzed, 88/146 (60%) were CP-CRE and 58/146 (40%) were non-CP-CRE. Patients with CP-CRE bacteremia were less likely to receive active empiric or targeted antibiotic therapy. Non-CP-CRE bacteremia was associated with a 2.4 times higher hazard of death at 30 days after bacteremia onset compared to CP-CRE (HR, 2.4; 95% CI, 1.2, 4.6). Patients with non-CP-CRE bacteremia had a higher hazard of death at 30 days after bacteremia onset compared to those with CP-CRE bacteremia.

Hovan MR ，Narayanan N ，Cedarbaum V ，Bhowmick T ，Kirn TJ ... -  《-》