cephalosporinase


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Related to cephalosporinase: penicillinase

cephalosporinase

 [sef″ah-lo-spor´in-ās]
an enzyme that hydrolyzes the CO-NH bond in the lactam ring of cephalosporin, converting it to an inactive product.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

β-lac·ta·mase

(lak'tă-mās),
An enzyme produced by many species of bacteria that disrupts the four-membered β-lactam ring of penicillin and cephalosporin groups of antibiotics, destroying their antimicrobial activity. The ability of an organism to produce a β-lactamase may be chromosomal and constitutive or a plasmid-associated acquired property.
Farlex Partner Medical Dictionary © Farlex 2012
References in periodicals archive ?
AmpC [beta]-lactamases are mostly chromosomally mediated cephalosporinases produced by Gram-negative bacteria that make them resistant to a wide range of beta lactam drugs thereby leading to serious problem in therapy.
Three Yersinia enterocolitica AmpD homologs participate in the multi-step regulation of chromosomal cephalosporinase AmpC.
Mahdian et al., "Role of efflux pumps: MexAB-OprM and MexXY (-OprA), AmpC cephalosporinase and OprD porin in non-metallo-[beta]-lactamase producing Pseudomonas aeruginosa isolated from cystic fibrosis and burn patients," Infection, Genetics and Evolution, vol.
Genes encoding AmpC cephalosporinases (AmpC) may be chromosomal or plasmid-based in origin, whereas genes encoding extended-spectrum [beta]-lactamases (ESBLs) are most often carried on mobile genetic elements, such as plasmids or transposons, and cause resistance to all [beta]-lactams except carbapenems and cephamycins (1-4).
EXCENELTM (Ceftiofur Sodium) is a new Beta-Lactam, cephalosporinase resistant antibiotic from the third generation of the cephalosporins, chemically ceftiofur is the sodium salt of (6R,7R)-7{[(2-amino-4thiozolyl)-Z- (methoxyimino)acetyl]amino}-3-{[(2-furanylcarbonyl)thio]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate and is being marketed by Upjohn with the drugs name as EXCENELTM.
anthracis genome sequence shows that this organism encodes two beta-lactamases: a penicillinase and a cephalosporinase. Data in the literature also show that some betalactamase negative B.
(1) Reports have established regarding the development of resistance to these inhibitors which might be caused by the hyperproduction of unmodified TEM(TEM named after the patient, Temoniera, from whom it was isolated)-type [beta]-lactamase, or modification of the outer membrane proteins, or production of OXA (Oxacillinase)-type enzymes, or hyperproduction of cephalosporinases. (2-6) Since 1990, the emergence of inhibitor-resistant TEM [beta]-lactamases (IRT) has further compromised the effect of [beta]- lactamase inhibitors.
(4) In Enterobacteriaceae, antibiotic resistance due to the production of extended-spectrum 0-lactamase (ESBL-E) and overexpression of AmpC cephalosporinase (AmpC-E) is cause for great concern and produce a significant impact both on empirical and definitive therapy.
The DDST was also performed on MH agar plates (bioMerieux) containing cloxacillin (150 mg/L) to inhibit cephalosporinase activity of natural producers of those inducible cephalosporinases.