Vancomycin-resistant Enterococcus faecium: should we screen on admission?

Denmark has experienced an increase in the proportion of invasive vancomycin-resistant Enterococcus faecium (VRE) since 2002 (e.g. <4% in 2015, 7.1% in 2017 and 12% in 2018). At Rigshospitalet, we employ active screening at departments with high prevalence or in case of outbreaks. This includes the collection of rectal swabs specifically for VRE screening. Our purpose was to describe the carrier prevalence of vancomycin-resistant enterococci among acute patients admitted to the Neurointensive Care Unit, Department of Neuroanaesthesiology, Rigshospitalet, Copenhagen, Denmark (NICU). Between April 2018 and January 2019, we investigated 99 consecutive rectal swabs from patients admitted to NICU. The primary outcome was prevalence of VRE carriage. The median age was 64 years (range 23-87) and gender was equally distributed (Female = 47, Male = 46). 26 (28%) had previously been admitted within 179 days and 67 patients (72%) had no hospital admissions within 180 days prior to the admission to NICU. Of the 93 rectal swabs, 2 (2%, 95% CI 0.26-7.55%) were positive for vanA and none were positive for vanB. Routine screening of all patients at admission may be effective in hospital settings with high VRE prevalence, whereas the benefit of screening for VRE in hospitals with a low prevalence may be restricted to specific patient populations.

Mutational change of CTX-M-15 to CTX-M-127 resulting in mecillinam resistant Escherichia coli during pivmecillinam treatment of a patient

Pivmecillinam (amdinocillin pivoxil) is the recommended first-choice antibiotic used to treat urinary tract infections (UTIs) in Denmark. The frequency of mutation to mecillinam (MEC) resistance is described as high in vitro; however, treatment of UTI has a good clinical response and prevalence of mecillinam resistance in Escherichia coli remains low despite many years of use. We describe occurrence of in vivo mecillinam resistance in a clinical isolate of ESBL-producing E. coli following pivmecillinam treatment. The identified phenotypic differences in the mecillinam resistant isolate compared with the original mecillinam susceptible isolate were a full-length LPS with O-antigen (O25), mecillinam resistance and a lower MIC for ceftazidime. Regarding genotype, the resistant isolate differed with a mutation in blaCTX-M-15 to blaCTX-M-127 , loss of a part of a plasmid and a genomic island, respectively, and insertion of a transposase in wbbL, causing the rough phenotype. The observed mecillinam resistance is expected to be caused by the mutation in blaCTX-M-15 with additional contribute from the serotype shift. We continue to recommend the use of pivmecillinam as first-line treatment for UTI.

Piperacillin/tazobactam vs carbapenems for patients with bacterial infection: Protocol for a systematic review

INTRODUCTION

Early empirical broad-spectrum antimicrobial therapy is recommended for patients with severe infections, including sepsis. β-lactam/β-lactamase inhibitor combinations or carbapenems are often used to ensure coverage of likely pathogens. Piperacillin/tazobactam is proposed as a carbapenem-sparing agent to reduce the incidence of multidrug-resistant bacteria and superinfections. In the recently published MERINO trial, increased mortality from piperacillin/tazobactam was suggested in patients with bacteraemia with resistant Escherichia coli or Klebsiella species. Whether these findings also apply to empirical piperacillin/tazobactam in patients with other severe infections, including sepsis, is unknown. We aim to assess the benefits and harms of empirical and definitive piperacillin/tazobactam vs carbapenems for patients with severe bacterial infections.

METHODS AND ANALYSIS

This protocol has been prepared according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols statement, the Cochrane Handbook and the Grading of Recommendations, Assessment, Development, and Evaluation approach. We will include randomised clinical trials assessing piperacillin/tazobactam vs carbapenems in patients with severe bacterial infections of any origin. The primary outcome will be all-cause short-term mortality ≤ 90 days. Secondary outcomes will include all-cause long-term mortality > 90 days, adverse events, quality of life, use of life support, secondary infections, antibiotic resistance, and length of stay. We will conduct meta-analyses, including pre-planned subgroup and sensitivity analyses for all assessed outcomes. The risk of random errors in the meta-analyses will be assessed by trial sequential analysis.