Risk Factors for Fecal Carriage of Extended-Spectrum Beta-Lactamase Producing Escherichia coli and Klebsiella spp. in the Community.

Aim: Community-acquired infections caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria are an emerging problem. Digestive tract colonization is a prerequisite for infections by ESBL-producing microorganisms. The aim of this study was to determine the prevalence of and risk factors for fecal carriage of ESBL-producing Escherichia coli ( E. coli) or Klebsiella spp. in the community. Materials and Methods: A total of 928 stool samples admitted to the laboratory during a four-month period were included in the study. Samples were diluted in saline and cultured in two EMB agar plates supplemented with either 1 μg/ml cefotaxime or 1 μg/ml ceftazidime. All isolates that grew were identified to the species level. E. coli and Klebsiella spp. strains were tested for ESBL production with ceftazidime and ceftazidimeclavulanate discs according to the Clinical and Laboratory Standards Institute (CLSI) Guideline. Results: Of the 928 stool samples included, 133 (14%) were isolated from inpatients and 795 (86%) from outpatients. Sixty-three (47.3%) of 133 hospitalized and 121 (15.2%) of 795 outpatients harbored ESBL-producing E. coliand Klebsiellaspp. (P = 0.000). Chronic hepatic failure (OR: 8.7, CI: 1.65–46.12; P = 0.011) and recent antibiotic use (OR: 4.4, CI: 1.76–11.16; P = 0.002) were found to be associated with ESBL positivity for the hospitalized patients. Recent antibiotic use (OR: 2.8, CI: 1.61-5.12; P = 0.000) was found to be the only independent variable associated with ESBL positivity for the outpatients. Conclusions: The high prevalence (15.2%) of fecal carriage of ESBL-producing bacteria in the community warrants further study in this field including the consequences of this colonization in the hospital setting. [ABSTRACT FROM AUTHOR]