Predicting antibiotic resistance in urinary-tract infection patients with prior urine cultures.
Antimicrob Agents Chemother. 2016 May 23;
Authors: Dickstein Y, Geffen Y, Andreassen S, Leibovici L, Paul M
BACKGROUND: To improve antibiotic prescribing, we sought to establish the probability of a resistant organism in urine culture given a previous resistant culture in a setting endemic for MDRs.
METHODS: We performed a retrospective analysis of inpatients with paired positive urine cultures. We focused on ciprofloxacin-resistant (cipro-r) Gram-negative bacteria, extended-spectrum beta-lactam (ESBL)-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae (CRE) and carbapenem-resistant non-fermenters (CRNF). Comparisons were made between frequency of each resistant phenotype following a previous culture with the same phenotype and overall frequency of that phenotype and odds ratios (OR) were calculated. We performed a regression to assess the effects of other variables on the likelihood of repeated resistant culture.
RESULTS: A total of 4409 patients (52.5% women, median age 70 years) with 19546 paired positive urine cultures were analyzed. The frequency of cipro-r, ESBL, CRE and CRNF amongst all cultures were 47.7%, 30.6%, 1.7% and 2.6%, respectively. ORs for repeated resistant phenotype were 1.87, 3.19, 48.25 and 19.02 for cipro-r, ESBL, CRE and CRNF, p<0.001 for all. At one month, the frequency of repeat resistance phenotype was 77.4%, 66.4%, 57.1% and 33.3% for cipro-r, ESBL, CRE and CRNF, respectively. Increasing time between cultures and the presence of an intervening non-resistant culture significantly reduced the chances of repeated resistance. Associations were statistically significant over the duration of follow-up (60 months) for CRE and up to six months for all other pathogens.
CONCLUSION: Knowledge of microbiology results in the six preceding months may assist antibiotic stewardship and improve appropriateness of empirical treatment for UTIs.
PMID: 27216064 [PubMed - as supplied by publisher]