1807. Extended spectrum beta lactamase producing E. coli in the community: risk factor analysis
Session: Poster Abstract Session: Resistant Gram-Negative Infections: Epidemiology
Saturday, October 10, 2015
Room: Poster Hall
Background: In our facility, 74.9% of all extended spectrum beta lactamase (ESBL)-producing E. coli is found in outpatients with urinary tract infection (UTI). There is a paucity of literature describing risk factors for community-onset (CO) ESBL UTI. The objective of this study is to determine risk factors that are associated with CO ESBL UTI.

Methods: All cases of ESBL UTI from January 2007 – December 2014 were identified and 3 controls were selected for each case and matched upon patient setting (outpatient), bacteria isolated (E. coli) and culture type (urine). Possible risk factors analyzed included: previous positive urine culture, male, age, diabetes, HIV, liver disease, hemodialysis, cardiovascular disease (CVD), irritable bowel syndrome, immunosuppression, recent surgery, recent hospitalization, length of hospital stay and recent antibiotics. A univariate analysis using the Chi-square or Wilcoxon rank-sum test was performed to determine significant associations with risk factors and an ESBL UTI. Logistic regression was performed for variables with univariate p-value <0.3. 

Results: 149 cases of CO ESBL UTI were identified and 422 controls were selected. Univariate analysis revealed previous positive urine culture, male, diabetes, hemodialysis, CVD, recent surgery, recent hospitalization and recent antibiotics to be associated with community-acquired ESBL UTI. In the multivariate logistic regression, previous positive urine culture, male, diabetes, recent antibiotics and age were significant predictors of ESBL UTI (Table 1).

 Conclusion: The significant association between ESBL UTI and exposure to antibiotics, diabetes, age and previous positive urine culture suggest that patients with CO ESBL UTI have more chronic illness than those with susceptible E. coliUTI. It is possible that outpatient antimicrobial stewardship could have a role in preventing acquisition of ESBL UTI.

Table 1: Multivariate analysis of risk factors for ESBL UTI




Risk Factor

E. coli

(n = 422)

ESBL E. coli

(n = 149)



95% CI

Previous positive urine culture, n (%)

5 (1)

28 (19)



2.5 – 25.1

Male, n (%)

41 (8)

45 (30)



1.2 – 3.7

Diabetes, n (%)

70 (17)

67 (45)



1.1 – 3.2

Antibiotics within 6 months, n (%)

13 (3)

38 (26)



1.7 – 8.2

Age (Mean, SD)

42 (18)

57 (19)



1.2 – 1.6


Sara Reese, PhD, CIC1, Bryan Knepper, MPH, MSc, CIC1, Connie Price, MD2 and Heather Young, MD2, (1)Patient Safety and Quality, Denver Health Medical Center, Denver, CO, (2)Infectious Diseases, Denver Health Medical Center, Denver, CO


S. Reese, None

B. Knepper, None

C. Price, None

H. Young, None

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