Be careful about MICs to amoxicillin for patients with Streptococci-related infective endocarditis

Int J Antimicrob Agents. 2019 Jun;53(6):850-854. doi: 10.1016/j.ijantimicag.2019.03.002. Epub 2019 Mar 7.

Abstract

Background: A variety of microorganisms can cause infective endocarditis (IE), with Staphylococci and Streptococci accounting for the majority of cases. Streptococci are a common cause of community-acquired IE but few studies have focused on this subgroup of endocarditis.

Methods: A retrospective multicentre study was conducted between 2012 and 2017 in 12 hospital centres in France. Data were extracted from the local diagnosis-related group database and matched with microbiological results. After identification, the records were retrospectively analysed.

Results: A total of 414 patients with streptococcal endocarditis were included. The patients were predominantly male (72.8%) and the median age was 73.2 years (interquartile range [IQR] 61.3-80.9). The majority of patients (70.6%) had native valve endocarditis. Embolic complications were seen in 38.8% of patients. Viridans group Streptococci (VGS) and bovis-equinus group Streptococci (BGS) accounted for 52.4% and 34.5% of isolated strains, respectively. Minimum inhibitory concentrations (MICs) of amoxicillin were <0.125, 0.125-2 and >2 mg/L for 59.6%, 27% and 1% of isolates, respectively. In-hospital mortality for patients with Streptococci-related IE was 17.8%. In multivariate analysis, the only factor associated with in-hospital mortality was MIC for amoxicillin between 0.25 and 2 mg/L (P = 0.04; OR = 2.23 [95% confidence interval (CI) 1.03-4.88]) whereas performance of cardiac surgery for IE was a protective factor (P = 0.001, OR = 0.23 [95% CI 0.1-0.56]).

Conclusions: IE remains a serious and deadly disease despite recent advances in diagnosis and treatment. Adaptation of antibiotic doses to MICs for amoxicillin and surgery may improve patient outcome.

Keywords: Infective endocarditis; Minimum inhibitory concentration; Streptococci.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Amoxicillin / pharmacology*
  • Anti-Bacterial Agents / pharmacology*
  • Endocarditis / epidemiology
  • Endocarditis / microbiology*
  • Endocarditis / mortality
  • Female
  • France / epidemiology
  • Hospitals
  • Humans
  • Male
  • Microbial Sensitivity Tests / methods
  • Middle Aged
  • Retrospective Studies
  • Risk Factors
  • Streptococcal Infections / epidemiology
  • Streptococcal Infections / microbiology*
  • Streptococcal Infections / mortality
  • Streptococcus / classification
  • Streptococcus / drug effects*
  • Streptococcus / isolation & purification
  • Survival Analysis
  • Young Adult

Substances

  • Anti-Bacterial Agents
  • Amoxicillin