Intestinal colonization due to Escherichia coli ST131: risk factors and prevalence.

Background: Escherichia coli sequence type 131 (ST131) is a successful clonal group that has dramatically spread during the last decades and is considered an important driver for the rapid increase of quinolone resistance in E. coli .

Methods: Risk factors for rectal colonization by ST131 Escherichia coli (irrespective of ESBL production) were investigated in 64 household members (18 were colonized) and 54 hospital contacts (HC; 10 colonized) of 34 and 30 index patients with community and nosocomial infection due to these organisms, respectively, using multilevel analysis with a p limit of < 0.1.

Result: Colonization among household members was associated with the use of proton-pump inhibitors (PPI) by the household member (OR = 3.08; 95% CI: 0.88-10.8) and higher age of index patients (OR = 1.05; 95% CI; 1.01-1.10), and among HC, with being bed-ridden (OR = 21.1; 95% CI: 3.61-160.0) and having a urinary catheter (OR = 8.4; 95% CI: 0.87-76.9).

Conclusion: Use of PPI and variables associated with higher need of person-to-person contact are associated with increased risk of rectal colonization by ST131. These results should be considered for infection control purposes.