Int J Antimicrob Agents. 2023 Mar 31:106800. doi: 10.1016/j.ijantimicag.2023.106800. Online ahead of print.
Aminopenicillins achieve urinary concentrations that exceed typical minimum inhibitory concentrations for enterococcal lower urinary tract infection (UTI). Our clinical microbiology laboratory discontinued routine susceptibilities on enterococcal urine isolates and reports "aminopenicillins are predictably reliable for uncomplicated enterococcal UTI". The study objective was to compare outcomes of aminopenicillins (AP) to non-aminopenicillins (NAP) for enterococcal lower UTIs. This was an IRB approved, retrospective cohort of adults hospitalized with symptomatic enterococcal lower UTIs from 2013-2021. Primary endpoint: composite clinical success at 14-days, defined as resolution of symptoms without new symptoms and no repeat culture growth of index organism. A non-inferiority analysis was utilized with a 15% margin, and logistic regression evaluated characteristics associated with 14-day failure. 178 subjects were included: 89 AP, 89 NAP. VRE was identified in 73 (82%) AP and 76 (85%) NAP patients (P=0.54); a total of 34 (38.2%) AP and 66 (74.2%) NAP patients had confirmed E. faecium (P<0.001). Amoxicillin (36, 40.5%) and ampicillin (36, 40.5%) were the most frequent AP utilized; linezolid (41, 46%) and fosfomycin (30, 34%) were the most frequent NAP. 14-day clinical success for AP and NAP was 83.1% and 82.0% (1.1% difference, 97.5%CI, -0.117-0.139). Among the E. faecium subgroup, 14-day clinical success was observed in 27/34 (79.4%) of AP and 53/66 (80.3%) of NAP patients (P=0.916). In logistic regression, APs were not associated with 14-day clinical failure (adjOR 0.84; 95%CI, 0.38-1.86). Aminopenicillins were noninferior to non-aminopenicillins for treating enterococcal lower UTIs and may be considered irrespective of susceptibility results.
PMID:37004756 | DOI:10.1016/j.ijantimicag.2023.106800