Impact of diversity of antibiotic use on the development of antimicrobial resistance
Issue date
2006Author
Sandiumenge, Alberto
Diaz, Emili
Rodriguez, Alejandro
Vidaur, Loreto
Canadell, Laura
Olona, Montserrat
Rello, Jordi
Suggested citation
Sandiumenge, Alberto;
Diaz, Emili;
Rodriguez, Alejandro;
Vidaur, Loreto;
Canadell, Laura;
Olona, Montserrat;
...
Rello, Jordi.
(2006)
.
Impact of diversity of antibiotic use on the development of antimicrobial resistance.
Journal of Antimicrobial Chemotherapy, 2006, vol. 57, núm. 6, p. 1197-1204.
https://doi.org/10.1093/jac/dkl097.
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Show full item recordAbstract
Objectives: To evaluate the impact of different antibiotic strategies on acquisition of resistant microorganisms.
Methods: A prospective study was conducted over a 44 month period in a single ICU. Four empirical
antibiotic strategies for ventilator-associated pneumonia (VAP) were sequentially implemented. Over
the initial 10 months, patient-specific antibiotic therapy was prescribed; then, 4 month periods of
prioritization or restriction rotation cycles of various antimicrobial agents were implemented for a total
of 24 months; and, finally, during the last 10 months (mixing period) the first-line antibiotic for VAP was
changed following a pre-established schedule to ensure maximum heterogeneity. Antibiotic consumption
was closely monitored every month, and antimicrobial resistance patterns were regularly assessed.
Antimicrobial heterogeneity was estimated using a modified Peterson index (AHI) measuring the ratios
for the five most used antibiotics. Colonization by targeted microorganisms and susceptibility patterns
were compared with the patient-specific period.
Results: Higher diversity of antibiotic prescription was obtained during patient-specific therapy (AHI = 0.93)
or mixing periods (AHI = 0.95) than during prioritization (AHI = 0.70) or restriction periods (AHI = 0.68). High
homogeneity was associated with increases in carbapenem-resistant Acinetobacter baumannii (CR-Ab)
[relative risk (RR) 15.5; 95%CI 5.5–42.8], extended-spectrum b-lactamase (ESBL)-producing Enterobacteriaceae
(RR 4.2; 95%CI 1.9–9.3) and Enterococcus faecalis (RR 1.7; 95%CI 1.1–2.9). During the restriction
period, incidence of ESBL-producing Enterobacteriaceae and E. faecalis returned to patient-specific rates
but CR-Ab remained higher.
Conclusions: Antibiotic prescription patterns balancing the use of different antimicrobials should be
promoted to reduce the selection pressure that aids the development of resistance.