beta-lactamase

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Related to b-lactamase: ESBL

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.

β-lactamase

/β-lac·ta·mase/ (lak´tah-mās) any of a group of enzymes, produced by almost all gram-negative bacteria, that hydrolyze the β-lactam ring of penicillins and cephalosporins, destroying their antibiotic activity. Individual enzymes may be called penicillinases or cephalosporinases based on their specificities.

beta-lactamase

(bā′tə-lăk′tə-mās′, -māz′, bē′-)
n.
Any of various enzymes that hydrolyze and inactivate beta-lactam antibiotics such as penicillin, found in many antibiotic-resistant bacteria.

beta-lactamase

[-lak′təmāz]
Etymology: lactam, a cyclic amide, ase, enzyme
a bacterial enzyme that catalyzes the hydrolysis of the beta-lactam ring of some penicillins and cephalosporins, producing penicilloic acid and rendering the antibiotic ineffective. Also called cephalosporinase, penicillinase.

be·ta-lac·ta·mase

(bā'tă lak'tā-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.
Synonym(s): penicillinase.

β-lactamase

either of two enzymes: β-lactamase I is penicillinase; β-lactamase II is cephalosporinase.
References in periodicals archive ?
Extended spectrum b-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria.
Isolates were screened for AmpC b-lactamase production by disc diffusion method as described by Clinical Laboratory Standards Institute (CLSI).
coli produced more than one type of b-lactamase (Such as TEM+CTX-M type) in Table IV.
KEY WORDS: b-Lactamase (bla) gene, Large-scale detection, Molecular diagnosis, Minimizing antibiotic resistance.
1 Gram negative bacteria including Escherichia coli and Klebsiella pneumoniae produce resistance threat with the evolution of multiple resistance mechanisms like enzyme production resulting in extended spectrum beta-lactamases, Amp C b-lactamases and now the carbapenemases especially metallo-beta-lactamases (MBLs).
Prevalence of AmpC and SHV b-Lactamases in Clinical Isolates of Escherichia coliF rom Tehran Hospitals.
These data confirm the presence of an extended spectrum b-lactamase (ESBL) producing IncHI2 plasmid in strain A54560 that is capable of con jugative transfer and suggest that the plasmid might have been acquired by residual index strain within the patient by transfer from an unknown donor bacterium.
Group 6 - Antibacterials B-lactam penicillin susceptible to B-lactamase
Multidrug-resistant Pseudomonas aeruginosa isolate co-expressing extended-spectrum b-lactamase PER-1 and metallo-b-lactamase VIM-2 from Turkey.
The reason for this is that many isolates were determined to be b-lactamase negative in spite of their resistance to some of the antibiotics.
Two disadvantages are its ineffectiveness against B-lactamase producing pathogens, and its inability to be used in clients with penicillin allergies.