Enterococcal bacteraemia: predictive and prognostic risk factors for ampicillin resistance

• Published in: Epidemiology and infection 2018-12, Vol.146 (16), p.2028-2035
• Main Authors: Matsumura, T, Nagao, M, Nakano, S, Yamamoto, M, Matsumura, Y, Ichiyama, S
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Ampicillin; Ampicillin Resistance; Antibacterial Resistance; Antibiotics; Antimicrobial agents; Bacteremia; Bacteremia - epidemiology; Bacteremia - microbiology; Bacteremia - mortality; Comorbidity; Confidence intervals; Demographics; Disease control; Drug resistance; Empirical analysis; Enterococcus faecalis - drug effects; Enterococcus faecalis - isolation & purification; Enterococcus faecium - drug effects; Enterococcus faecium - isolation & purification; Epidemiology; Female; Glycopeptides; Gram-Positive Bacterial Infections - epidemiology; Gram-Positive Bacterial Infections - microbiology; Gram-Positive Bacterial Infections - mortality; Hospitals; Hospitals, University; Humans; Infectious diseases; Japan - epidemiology; Laboratories; Male; Medical prognosis; Microbiology; Middle Aged; Mortality; Nosocomial infection; Nosocomial infections; Original Paper; Patients; Penicillin; Prevalence; Prognosis; Regression analysis; Resistance factors; Retrospective Studies; Risk analysis; Risk Factors; Staphylococcus infections; Statistical analysis; Survival Analysis; Trends; Variables; Young Adult
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268818002479

To identify the predictive and prognostic factors associated with ampicillin-resistant enterococcal bacteraemia, we retrospectively reviewed demographic, microbiological and clinical data of patients attending the Kyoto University Hospital, Japan, between 2009 and 2015. Logistic regression and Cox regression analyses were performed to determine the predictive and prognostic factors, respectively. In total, 235 episodes of enterococcal bacteraemia were identified. As ampicillin susceptibility was uniform for Enterococcus faecalis isolates and almost all ampicillin-resistant isolates were E. faecium, bacteraemia due to these species was investigated separately. E. faecalis and E. faecium accounted for 41.7% (98/235) and 48.1% (113/235) of the isolates, respectively and 91.2% of all E. faecium were ampicillin resistant. Nosocomial E. faecium bacteraemia acquisition (odds ratio (OR), 13.6; 95% confidence intervals, 3.16-58.3) was associated with ampicillin-resistant isolates. Bacteraemia from an unknown source (hazard ratio (HR), 2.91; 95% CI 1.36-6.21) and an increased Pitt bacteraemia score (PBS) (HR, 1.36; 95% CI 1.21-1.52) were associated with 30-day mortality in E. faecium infections. Likewise, bacteraemia from an unknown source (HR, 4.17; 95% CI 1.25-13.9) and increased PBS (HR, 1.27; 95% CI 1.09-1.48) were associated with 30-day mortality in patients with E. faecalis bacteraemia. The empirical therapeutic administration of glycopeptides is recommended for patients with bacteraemia from an unknown source in whom severe E. faecium bacteraemia is suspected.