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Any of several beta-lactamase enzymes that cleave the beta-lactam ring in penicillins. Penicillinases are found in many penicillin-resistant bacteria.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Medicine) any of a group of enzymes used to treat allergic reactions to penicillin
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.penicillinase - enzyme produced by certain bacteria that inactivates penicillin and results in resistance to that antibiotic
enzyme - any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
In disc diffusion tests, hyper-producers of penicillinase may show small methicillin or oxacillin zones of inhibition, whereas most true methicillin/oxacillin-resistant isolates give no zone.12
Furthermore, abscess drainage was not necessary in our patients; therefore, penicillinase resistant penicillin (oxacillin), ampicillin-sulbactam or amoxicillin-clavunate were given as the first choice of treatment in our paediatric patients (8-11).
There are different enzymes produced correspondingly against these antibiotics such as penicillinase, cephalosporinases, and carbapenemases22.
A 25-yearsurvey of antibiotic susceptibility testing in Staphylococcus aureus from bovine mastitis in Belgium, with special reference to penicillinase".
Since penicillinase is produced by the ratios of 95% in S.
It has a broad in vitro spectrum of antimicrobial activity against both Gram positive and Gram negative bacteria and is penicillinase resistant [4-12].
These resistances are related in part to a Ser-91Phe substitution in gyrA for ciprofloxacin (Fluoroquinolones) resistant gonococcal strains, a tetM gene for plasmid-mediated tetracycline resistance (TRNG), and a penicillinase encoding plasmids (Asian, African, Toronto, Rio, Nlmes, New Zealand, and Johannesburg) for plasmid-mediated penicillin resistance (PPNG).
* The first wave began in mid-1940s with emergence of penicillin-resistance, because of plasmid encoded penicillinase that hydrolyses the beta-lactam ring of penicillin essential for its antimicrobial activity.
According to the studies, the percentage of methicillin resistant Staphylococcus aureus prevalence is due to different plans of hospitals and the less capability of coupling with penicillin binding proteins for antibiotics with beta-lactam ring and the excess of penicillinase production [22].
For patient safety, nurses must review ordered antibiotics to assure no penicillin or penicillinase drugs are administered (Lexicomp, 2015).

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