biostudies-literatureUnknown15(5-6)Li GLWe investigated the occurrence of AmpC beta-lactamases among Escherichia coli and Klebsiella pneumoniae isolates and determined the genotype of plasmid-mediated AmpC beta-lactamases at a medical center. The AmpC beta-lactamase promoter and attenuator were amplified from chromosomal DNA of high AmpC-producing E. coli isolates and sequenced. Antibiotic screening and 3D extract tests showed the presence of AmpC beta-lactamase in 3.56% of K. pneumoniae and 1.88% of E. coli isolates. Ten isolates (six K. pneumoniae and four E. coli) were positive for extended spectrum beta-lactamase (ESBL) as indicated by the double disc diffusion method. DHA-1 plasmid-encoded AmpC beta-lactamase was present in 10 K. pneumoniae isolates and four E.coli isolates. E. coli chromosomal AmpC beta-lactamase carried pGene expression215-23https://www.ebi.ac.uk/biostudies/studies/S-EPMC6043836biostudies-literatureIdentification of genotypes of plasmid-encoded AmpC beta-lactamases from clinical isolates and characterization of mutations in their promoter and attenuator regions.PMC6043836Luan YWang CYDuo LBSun QZhang HGLi GLWang WPQi GYfalseIdentification of genotypes of plasmid-encoded AmpC beta-lactamases from clinical isolates and characterization of mutations in their promoter and attenuator regions.We investigated the occurrence of AmpC beta-lactamases among Escherichia coli and Klebsiella pneumoniae isolates and determined the genotype of plasmid-mediated AmpC beta-lactamases at a medical center. The AmpC beta-lactamase promoter and attenuator were amplified from chromosomal DNA of high AmpC-producing E. coli isolates and sequenced. Antibiotic screening and 3D extract tests showed the presence of AmpC beta-lactamase in 3.56% of K. pneumoniae and 1.88% of E. coli isolates. Ten isolates (six K. pneumoniae and four E. coli) were positive for extended spectrum beta-lactamase (ESBL) as indicated by the double disc diffusion method. DHA-1 plasmid-encoded AmpC beta-lactamase was present in 10 K. pneumoniae isolates and four E.coli isolates. E. coli chromosomal AmpC beta-lactamase carried p2012-01-01T00:00:00Z20122025-04-04T19:25:07.755Z2019-03-26T23:50:12ZS-EPMC60438362353989910.3727/105221613x13571653093204