Novel insights into pivotal risk factors for rectal carriage of extended-spectrum-beta-lactamase-producing enterobacterales within the general population in Lower Saxony, Germany

AIMS: To estimate the prevalence of extended-spectrum-β-lactamase (ESBL)-producing enterobacterales (ESBL-E) carriage in the general population of Lower Saxony, Germany, and to identify risk factors for being colonised.

METHODS AND RESULTS: Participants were recruited through local press and information events. Detection of ESBL-E by culture was conducted using ESBL-selective chromagar plates containing third generation cephalosporins. Identification of pathogens was performed using Matrix Assisted Laser Desorption Ionization Time-of-Flight-Technology on Vitek mass spectrometry. Antibiotic susceptibility testing was conducted by microdilution (Vitek II) and an ESBL confirmation assay was carried out using a combination disk test. Of 527 randomly collected stool samples from healthy volunteers, 5.5% were tested positive for ESBL-E. Post-stratification for age and gender yielded a similar population estimate (5.9%). People traveling abroad and taking antibiotics had the greatest rectal ESBL-E carriage.

CONCLUSIONS: Potential risk factors (e.g., working in healthcare facilities, recent inpatient stay) did not attribute to rectal ESBL-E carriage as other factors (e.g., traveling, taking antibiotics). Rectal ESBL-E carriage within the general population seems to be high.

SIGNIFICANCE AND IMPACT OF STUDY: The known risk factors for carriage with MDRO might not be fully applicable to ESBL-E and require further examination in order to develop effective strategies for the prevention of ESBL-E dissemination within the general population.