Bovine Intestinal Bacteria Inactivate and Degrade Ceftiofur and Ceftriaxone with Multiple β-Lactamases

• Published in: Antimicrobial Agents and Chemotherapy 2011-11, Vol.55 (11), p.4990-4998
• Main Authors: Wagner, R. Doug, Johnson, Shemedia J, Cerniglia, Carl E, Erickson, Bruce D
• Format: Article
• Language: English
• Subjects: Animals; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacillus cereus; Bacillus cereus - enzymology; Bacillus cereus - metabolism; bacteria; Bacteroides; Bacteroides - enzymology; Bacteroides - metabolism; beta-lactamase; beta-Lactamases; beta-Lactamases - genetics; beta-Lactamases - metabolism; Bifidobacterium - enzymology; Bifidobacterium - metabolism; Bifidobacterium breve; Biological and medical sciences; Cattle; ceftiofur; Ceftriaxone; Ceftriaxone - metabolism; Cephalosporins; Cephalosporins - metabolism; Chromatography, High Pressure Liquid; Clostridium; Clostridium - enzymology; Clostridium - metabolism; colon; DNA; Eubacterium - enzymology; Eubacterium - metabolism; Eubacterium biforme; feces; fungi; genes; intestinal microorganisms; Intestines; Intestines - microbiology; isoelectric focusing; liquid chromatography; Mass Spectrometry; Mechanisms of Resistance; Medical sciences; Pharmacology. Drug treatments; Polymerase Chain Reaction
• ISSN: 0066-4804; 1098-6596
• DOI: 10.1128/AAC.00008-11

The veterinary cephalosporin drug ceftiofur is rapidly degraded in the bovine intestinal tract. A cylinder-plate assay was used to detect microbiologically active ceftiofur, and high-performance liquid chromatography-mass spectrometry analysis was used to quantify the amount of ceftiofur remaining after incubation with bovine intestinal anaerobic bacteria, which were isolated from colon contents or feces from 8 cattle. Ninety-six percent of the isolates were able to inactivate ceftiofur to some degree, and 54% actually degraded the drug. None of 9 fungal isolates inactivated or degraded ceftiofur. Facultative and obligate anaerobic bacterial species that inactivated or degraded ceftiofur were identified with Vitek and Biolog systems, respectively. A subset of ceftiofur degraders also degraded the chemically similar drug ceftriaxone. Most of the species of bacteria that degraded ceftiofur belonged to the genera Bacillus and BACTEROIDES: PCR analysis of bacterial DNA detected specific β-lactamase genes. Bacillus cereus and B. mycoides isolates produced extended-spectrum β-lactamases and metallo-β-lactamases. Seven isolates of Bacteroides spp. produced multiple β-lactamases, including possibly CepA, and metallo-β-lactamases. Isolates of Eubacterium biforme, Bifidobacterium breve, and several Clostridium spp. also produced ceftiofur-degrading β-lactamases. An agar gel overlay technique on isoelectric focusing separations of bacterial lysates showed that β-lactamase enzymes were sufficient to degrade ceftiofur. These results suggest that ceftiofur is inactivated nonenzymatically and degraded enzymatically by multiple β-lactamases from bacteria in the large intestines of cattle.