Risk factors for fecal carriage of extended-spectrum beta-lactamase-producing and carbapenem-resistant Escherichia coli and Klebsiella pneumoniae strains among patients at hospital admission

Abstract

Aim: Extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant (CR) Enterobacteriaceae are substantial problems in hospital-acquired infections worldwide. We analyzed the risk factors for fecal carriage of ESBL-positive and/or CR E. coli and K. pneumoniae (EcKp) strains in a hospital in Turkey, an endemic country for both resistances.

Materials and methods: A prospective cross-sectional study including the rectal swab samples of 168 patients, obtained at the day of admission, was conducted. ESBL-producing and CR EcKp were investigated with phenotypic tests and PCR, and the clonal relatedness of isolates was studied. Risk analysis was performed with logistic regression method.

Results: A total of 67 (39.8%) and 21 (12.5%) patient samples tested positive for ESBL-producing and CR EcKp, respectively. CTX-M (n = 27) and OXA-48 (n = 12) were the dominant ESBL and carbapenemase types, and 4.5%-10.7% of the isolates were clonally-related. Among 15 potential risk factors studied, longer lengths of hospital stay and antimicrobial use, and receiving total parenteral nutrition in the last 6 months were determined as independent risk factors for fecal carriage of ESBL-producing and/or CR EcKp, while prior antimicrobial treatment was only a risk factor for ESBL producers.

Conclusion: Certain conditions in patients' medical backgrounds may be associated with increased likelihood of resistant bacterial colonization. Notably, questioning these situations at admission can help to identify potential carriers and proactively administer appropriate infection control measures.

Keywords: ESBL; Enterobacteriaceae; Intestinal colonization; Risk analysis.