ObjectivesThe aim of this study was to determine the prevalence of extended-spectrum β-lactamase (ESBL) and carbapenemase production among Enterobacteriaceae isolated from ambulatory patients with gastrointestinal complaints admitted to El-Ahrar General Hospital, Zagazig, Egypt in the period between January 2013 and May 2013.MethodsOne hundred and thirteen Enterobacteriaceae isolates were recovered from 100 consecutive Egyptian patients with community–onset gastrointestinal complaints. The fecal samples were plated directly on selective EbSA-ESBL Screening Agar and on MacConkey agar. Isolate identification was performed with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Screening for ESBLs and carbapenemases production was done by both the automated VITEK®2 system with AST N198 and by disk diffusion method. Real-time PCR and sequencing were used to characterize the resistance genes. Phylogroups of the E. coli isolates were determined by a triplex PCR-based method.ResultsOf 100 patients screened for fecal colonization with extended-spectrum β-lactamase -producing Enterobacteriaceae (ESBL-E) and carbapenemase- producing Enterobacteriaceae (CPE), 68 were colonized with ESBL-E whereas five patients were positive for CPE. One hundred and thirteen Enterobacterceae isolates were recovered from 100 fecal samples, they belonged to E. coli (n = 72), Klebsiella pneumoniae (n = 23), Enterobacter cloacae(n = 3), Salmonella spp. (n = 1) and other Enterobacterceae isolates (n = 14). The bla CTX-M gene was detected in 89.04% (65/73) of the ESBL-producing Enterobacteriaceae, whereas bla SHV and bla TEM were detected in 30.14% (22/73) and 19.18% (14/73) respectively. Three out of 5 carbapenem-resistant isolates harbored New Delhi metallo-beta-lactamase (NDM) and 2 produced Verona integron-encoded metallo- beta -lactamase (VIM). Twenty-two (47.83%) of the ESBL positive isolates were multidrug resistant (MDR). Phylogenetic analysis showed that, of the 51 ESBL-EC isolates, 17 belonged to group B2, 13 to group D, 11 to group A and 10 to group B1.ConclusionsNearly two-thirds of the Enterobacteriaceae isolates recovered from feces of ambulatory patients with community–onset gastrointestinal complaints admitted to El-Ahrar General Hospital, Zagazig, Egypt were ESBL producers and one in every 20 patients included in our study was colonized by carbapenemase-producing Enterobacteriaceae. These high colonization rates are worrying, therefore prudent antimicrobial use should be adopted in Egyptian community settings.