Clinical outcomes of urinary tract infection caused by extended spectrum beta-lactamase producing Enterobacteriaceae: a retrospective observational study comparing patients with and without systemic inflammatory response syndrome.

Aim: In severe urinary tract infection (UTI), susceptible antibiotics should be given. With the recent increase of multidrug-resistant bacteria, especially extended spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E), broad-spectrum antibiotics, such as carbapenems, are used more frequently, which could lead to a further increase of multidrug-resistant bacteria. We aimed to analyze the relationship between initial empirical antibiotic appropriateness and clinical outcomes in UTI, especially in patients with systemic inflammatory response syndrome (SIRS) and ESBL-E.

Methods: A retrospective observational study from 2012 to 2017.

Results: Among urine culture-positive cases with ≥10 colony-forming units/mL ( = 1,880), true UTI cases were extracted ( = 844) and divided into the SIRS group ( = 336 [ESBL-E12.8% (43/336)]) and non-SIRS group ( = 508 [ESBL-E12.6% (64/508)]). In the SIRS ESBL-E group, the initial antibiotics were susceptible in 55.8% (24/43), among which 91.7% (22/24) improved and 8.3% (2/24) deteriorated or died. The initial antibiotics were resistant in 44.2% (19/43), among which 47.4% (9/19) improved with the initial antibiotics, 47.4% (9/19) improved after escalating antibiotics, and 5.3% (1/19) deteriorated or died. In the SIRS group, 14 cases had true bacteremia with ESBL-E. Seven cases were initiated with inappropriate antibiotics; four cases showed improvement before or without antibiotic change and three cases improved after antibiotic escalation.

Conclusion: Initiation of narrow-spectrum antibiotics in septic UTI with ESBL-E might not deteriorate the clinical outcome if promptly escalated on clinical deterioration or with ESBL-E culture results. Further investigation is warranted to guide judicious use of initial antibiotics.