LJUBLJANA, SLOVENIA – , Johannes Huebner, MD, reported at the annual meeting of the European Society for Paediatric Infectious Diseases.
He presented a retrospective analysis of S. aureus isolates obtained from 540 patients at the Dr. von Hauner Children’s Hospital, Munich, from 2002 to 2017. All were either newly identified methicillin-resistant S. aureus (MRSA) or specimens from bacteremic children with invasive MRSA or methicillin-sensitive S. aureus (MSSA). The strains were tested for vancomycin resistance and minimum inhibitory concentration (MIC). The results from the 200 isolates obtained from 2002 to 2009 were then compared to the 340 specimens from 2010 to 2017, when antibiotic stewardship programs rose to the fore at the pediatric hospital.
All samples proved to be vancomycin sensitive. The further good news was there was absolutely no evidence of the worrisome vancomycin MIC creep that has been described at some centers. On the contrary, the MIC was significantly lower in the later samples, at 0.99 mcg/mL, compared with 1.11 mcg/mL in the earlier period. Moreover, the prevalence of heterogeneous glycopeptide-intermediate S. aureus (hGISA) – a phenotype that has been associated with increased rates of treatment failure – improved from 25% in the earlier period to 6% during the later period, reported Dr. Huebner, head of the division of pediatric infectious diseases at the children’s hospital, part of the University of Munich.
Vancomycin MICs weren’t significantly different between the MRSA and MSSA samples.
Based upon this favorable institutional experience, vancomycin remains the first-line treatment for suspected severe gram-positive cocci infections as well as proven infections involving MRSA at Dr. von Hauner Children’s Hospital.
These vancomycin MIC and hGISA data underscore the importance of periodically monitoring local S. aureus antimicrobial susceptibilities, which, as in this case, can differ from the broader global trends. The vancomycin MIC creep issue hadn’t been studied previously in German hospitals, according to Dr. Huebner.
He and his coworkers have published details of the elements of pediatric antibiotic stewardship programs they have found to be most effective (Infection. 2017 Aug;45[4]:493-504) as well as a systematic review of studies on the favorable economic impact of such programs (J Hosp Infect. 2019 Aug;102[4]:369-376).
Dr. Huebner reported having no financial conflicts regarding his study, which was conducted free of commercial support.