Risk factors for relapse or persistence of bacteraemia caused by Enterobacter spp.: a case–control study

Abstract

Background Enterobacter spp. possess chromosomal AmpC beta-lactamases that may be expressed at high levels. Previous studies have demonstrated a risk of relapsed bacteraemia following therapy with third generation cephalosporins (3GCs). What additional factors predict microbiological failure in Enterobacter bacteraemia is unclear. We aimed to determine factors associated with microbiological failure in Enterobacter bacteraemia.MethodsWe retrospectively identified cases of bacteraemia caused by Enterobacter spp. occurring in four hospitals. Using a case–control design, we determined clinical risk factors for persistence or relapse defined as repeated positive blood cultures collected between 72 hours and up to 28 days post initial positive blood culture.ResultsDuring the study period a total of 922 bacteraemia events caused by Enterobacter spp. in adults were identified. The overall risk of relapsed or persisting bacteraemia at 28 days was low (31 of 922, 3.4%), with only 2 patients experiencing emergent resistance to 3GCs. A total of 159 patients were included in the case–control study. Using multivariate logistic regression, independent predictors for relapse were a line-associated source of infection (OR 3.87; 95% CI 1.56-9.60, p = 0.004) and the presence of immunosuppression (OR 2.70; 95% CI 1.14-6.44, p = 0.02). On univariate analysis definitive therapy with a broad-spectrum beta-lactam-beta-lactamase inhibitor (BLBLI, e.g. piperacillin-tazobactam) was not associated with relapse (OR 1.83; 95% CI 0.64-5.21, p = 0.26) although the proportion of patients receiving a BLBLI as definitive therapy was relatively small (21/159, 13.2%).ConclusionsThe risk of relapsed or persistent Enterobacter bacteraemia appears to be low in Australia. A line-associated source of infection and immunocompromise were significant independent predictors for relapse. Larger, preferably randomized, studies are needed to address whether BLBLIs represent an effective carbapenem-sparing option for Enterobacter bacteraemia.Electronic supplementary materialThe online version of this article (doi:10.1186/s13756-017-0177-0) contains supplementary material, which is available to authorized users.

Changing Antimicrobial Resistance Trends in Kathmandu, Nepal: A 23-Year Retrospective Analysis of Bacteraemia

“…In this retrospective analysis of bacteraemia from a single hospital in Kathmandu, we report a 13.5% bacterial isolation rate from blood cultures, which is comparable with other bacteraemia studies from Nepal and elsewhere ( 5 , 20 – 22 ). Similarly, the array of isolated organisms was similar to those reported in other studies investigating the etiology of bloodstream infections ( 2 , 3 , 22 – 25 ), and childhood septicaemia ( 5 , 11 , 25 , 26 ). The most common Gram-negative, non- Salmonella organisms to be isolated from blood cultures within this population were Enterobacter spp., followed by Acinetobacter spp., E. coli and Klebsiella spp., a distribution that has been observed previously ( 3 , 5 , 23 , 27 ).…”

“…bacteraemia ( 28 ). This escalation is cause for concern, as this bacterial genus presents particular challenges for the selection of optimal antimicrobial therapy due to the presence of chromosomally encoded AmpC beta-lactamases ( 25 ). Among the Gram-positive organisms (excluding Coagulase negative Staphylococci , which were reported for neonates only), S. aureus , Non-haemolytic Streptococci and S. pneumoniae were the most commonly isolated pathogens from blood cultures; this is also a common array of organisms associated with bacteraemia ( 5 , 8 , 24 , 29 ).…”

Beta-Lactam/Beta-Lactamase Inhibitor Therapy for Potential AmpC-Producing Organisms: A Systematic Review and Meta-Analysis

“…A complete review of the articles yielded 5 new studies [9–13], which were used to update the previous meta-analysis of 8 studies [5] comprising 665 patients. One study included patients who were already reported in the previous meta-analysis [11] and so to avoid double counting we only included those patients in the later group. In total, 13 studies (including our unpublished data) and 1021 patients were included in the meta-analysis.…”

Privacy-first health research with federated learning

“…This bacteremia database involves 159 case-controlled cases of bacteraemia occurring among those of age 17 or over at four hospitals in Queensland and New South Wales, Australia between 1998 and 2015 ( Harris et al 2017 ). The data is used to predict risk factors associated with relapsed infection in patients with Enterobacer bacteraemia, based on multiple factors including age, sex, location, source of infection, hospital location, co-morbid conditions, and many other clinical factors.…”