title: Cross-class resistance to non-beta-lactam antimicrobials in extended-spectrum beta-lactamase-producing Klebsiella pneumoniae.
abstract: Extended spectrum beta-lactamases are modified beta-lactamase enzymes that impart resistance to third-generation cephalosporins and make all beta-lactam antibiotics and cephalosporins useless for therapy. We compared the antimicrobial susceptibility profiles of extended-spectrum beta-lactamase (ESBL)-producing and non-ESBL-producing isolates of Klebsiella pneumoniae. The ESBL producers had significantly diminished susceptibility compared with the non-ESBL producers for gentamicin (P < .001), tobramycin (P < .001), amikacin (P < .005), trimethoprim-sulfamethoxazole (P < .01), ciprofloxacin (P < .001), and nitrofurantoin (P < .001). All isolates were susceptible to imipenem. ESBL-producing K pneumoniae may also be resistant to non-beta-lactam antibiotics. Therefore, susceptibility testing of these isolates is critical for guiding therapy.
authors.affiliation: Section of Clinical Microbiology, Department of Clinical Pathology, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Procop
authors.forename: Marion J
authors.initials: MJ
authors.lastname: Tuohy
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Wilson
authors.forename: Delisa
authors.initials: D
authors.lastname: Williams
authors.forename: Emilia
authors.initials: E
authors.lastname: Hadziyannis
authors.forename: Gerri S
authors.initials: GS
authors.lastname: Hall
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology*; D008826:Microbial Sensitivity Tests; D018440:beta-Lactam Resistance / Q000502:physiology*; D001618:beta-Lactamases / Q000096:biosynthesis*; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases