Prevalence of Antibiotic Resistance Over Time in a Third-Level University Hospital

This study evaluated the spread and possible changes in resistance patterns of ESKAPE bacteria to first-choice antibiotics from 2015 to 2019 at a third-level university hospital after persuasive stewardship measures were implemented. Isolates were divided into three groups (group 1, low drug-resistant; group 2, multidrug/extremely drug-resistant; and group 3, pan-resistant bacteria) and a chi-squared test (χ²) was applied to determine differences in their distributions. Among the 2,521 isolates, Klebsiella pneumoniae was the most frequently detected (31.1%). From 2015 to 2019, the frequency of isolates in groups 2 and 3 decreased from 70.1% to 48.6% (χ² = 63.439; p < 0.0001). Stratifying isolates by bacterial species, for K. pneumoniae, the frequency of PDR isolates decreased from 20% to 1.3% (χ² = 15.885; p = 0.003). For Acinetobacter baumannii, a statistically significant decrease was found in groups 2 and 3: from 100% to 83.3% (χ² = 27.721; p < 0.001). Also, for Pseudomonas aeruginosa and Enterobacter spp., the frequency of groups 2 and 3 decreased from 100% to 28.3% (χ² = 225.287; p < 0.001) and from 75% to 48.7% (χ² = 15.408; p = 0.003), respectively. These results indicate that a program consisting of persuasive stewardship measures, which were rolled out during the time frame of our study, may be useful to control drug-resistant bacteria in a hospital setting.