Cloning and characterization of the endogenous cephalosporinase gene cepA from Bacteroides fragilis reveals a new subgroup of Ambler class A beta-lactamases.
- ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)
- Anita C. Parker (Creator)
- Marc B. Rogers (Creator)
- C. Jeffrey Smith (Creator)
- Institution
- East Carolina University (ECU )
- Web Site: http://www.ecu.edu/lib/
Abstract: Bacteroides frgiglis CS30 is a clinical isolate resistant to high concentrations of benzylpenicillin and cephaloridine but not to cephamycin or penem antibiotics. beta-Lactam resistance is mediated by a chromosomally encoded cephalosporinase produced at a high level. The gene encoding this beta-lactamase was cloned from genomic libraries constructed in Escherichia coli and then mated with B. fragilis 638 for identification of ampicillin-resistant (Apr) strains. Apr transconjugants contained a nitrocefin-reactive protein with the physical and enzymatic properties of the original CS30 isolate. The beta-lactamase gene (cepA) was localized by deletion analysis and subcloned and its nucleotide sequence was determined. The 903-bp cepA open reading frame encoded a 300-amino-acid precursor protein (predicted molecular mass 34 070 Da). A 13-lactamase-deficient mutant strain of B. fiugilis 638 was constructed by insertional inactivation with the cepA gene of CS30 demonstrating strict functional homology between these chromosomal beta-lactamase genes. An extensive comparison of the CepA protein sequence by alignment with other beta-lactamases revealed the strict conservation of at least four elements common to Ambler class A. A further comparison of the CepA protein sequence with protein sequences of beta-lactamases from two other Bacteroides species indicated that they constitute their own distinct subgroup of class A beta-lactamases. Originally published Antimicrobial Agents and Chemotherapy Vol. 37 No. 11 Nov 1993
Additional Information
- Publication
- Other
- Antimicrobial Agents and Chemotherapy. 37:11(November 1993) p. 2391-2400.
- Language: English
- Date: 2011
- Keywords
- Bacteroides fragilis, beta-lactamase, cephalosporinase
| Title | Location & Link | Type of Relationship |
| Cloning and characterization of the endogenous cephalosporinase gene cepA from Bacteroides fragilis reveals a new subgroup of Ambler class A beta-lactamases. | http://hdl.handle.net/10342/3372 | The described resource references, cites, or otherwise points to the related resource. |