Glycopeptide resistance among coagulase- negative staphylococci that cause bacteremia: epidemiological and clinical findings from a case-control study

A 1-year prospective case-control study (ratio of control patients to case patients, 3:1) was performed to assess
the incidence, risk factors, and genotypic patterns of bacteremia caused by glycopeptide-resistant coagulasenegative
staphylococci (CoNS) and their correlation with hospital glycopeptide use. Among 535 subjects with
CoNS bacteremia, 20 subjects had a glycopeptide-resistant strain (19 strains were resistant to teicoplanin and
1 was resistant to both teicoplanin and vancomycin). The percentage of resistant isolates recovered in 1 year
was 8% in intensive care units and 3% and 2% in medical and surgical wards, respectively. Genotypic analysis
of resistant strains showed different patterns with a high degree of polymorphism. Use of glycopeptides in
individual wards was not statistically associated with the percentage of resistance. Previous exposure to β-lactams
and glycopeptides, multiple hospitalization in the previous year, and concomitant pneumonia were
significantly associated with the onset of glycopeptide-resistant CoNS bacteremia. Mortality rates were 25%
among case patients and 18% among control patients, and they were significantly higher among patients who
presented with concomitant pneumonia and a high Acute Physiology and Chronic Health Evaluation III score.