Acquisition of Extended-Spectrum β-Lactamases by Escherichia coli and Klebsiella pneumoniae in Gut Microbiota of Pilgrims during the Hajj Pilgrimage of 2013.

We reported the acquisition of extended-spectrum-β-lactamase (ESBL)-producing bacteria in rectal samples of 129 pilgrims during the 2013 Hajj (pilgrimage to Makkah). When returning from the Hajj, there was a significant increase in the number of pilgrims carrying E. coli resistant to ceftriaxone (P = 0.008). The CTX-M gene was detected in rectal samples, with the detection rate increasing from 10.08% to 32.56% of samples after the Hajj (P < 0.001).