Biomaterial Database

Influence of beta-lactamase inhibitors on the activity of oxacillin against methicillin-resistant Staphylococcus aureus. 1995

S C Chang, and W C Hsieh, and K T Luh

Department of Internal Medicine, National Taiwan University Hospital, ROC.

We studied the in vitro susceptibility to oxacillin of 46 isolates of methicillin-resistant Staphylococcus aureus (MRSA) isolates with a minimum inhibitory concentration (MIC) > 8 micrograms/ml of oxacillin, with and without adding clavulanic acid, sulbactam, or tazobactam in three different concentrations (2, 4, and 8 micrograms/ml). All 46 strains were found by the rapid chromogenic cephalosporin method to be beta-lactamase producers. For those strains with low-level resistance (MIC of 16 or 32 micrograms/ml), the MICs of oxacillin decreased four- to 32-fold and two- to 32-fold after adding sulbactam and tazobactam, respectively. For those with high-level resistance (MIC of > or = 64 micrograms/ml), the MICs either did not change or decreased only two-fold after we added one of three beta-lactamase inhibitors. The results suggest that beta-lactamase production probably plays a role in resistance to oxacillin in those MRSA strains of low-level oxacillin resistance.

UI	MeSH Term	Description	Entries
D008826	Microbial Sensitivity Tests	Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).	Bacterial Sensitivity Tests,Drug Sensitivity Assay, Microbial,Minimum Inhibitory Concentration,Antibacterial Susceptibility Breakpoint Determination,Antibiogram,Antimicrobial Susceptibility Breakpoint Determination,Bacterial Sensitivity Test,Breakpoint Determination, Antibacterial Susceptibility,Breakpoint Determination, Antimicrobial Susceptibility,Fungal Drug Sensitivity Tests,Fungus Drug Sensitivity Tests,Sensitivity Test, Bacterial,Sensitivity Tests, Bacterial,Test, Bacterial Sensitivity,Tests, Bacterial Sensitivity,Viral Drug Sensitivity Tests,Virus Drug Sensitivity Tests,Antibiograms,Concentration, Minimum Inhibitory,Concentrations, Minimum Inhibitory,Inhibitory Concentration, Minimum,Inhibitory Concentrations, Minimum,Microbial Sensitivity Test,Minimum Inhibitory Concentrations,Sensitivity Test, Microbial,Sensitivity Tests, Microbial,Test, Microbial Sensitivity,Tests, Microbial Sensitivity
D010068	Oxacillin	An antibiotic similar to FLUCLOXACILLIN used in resistant staphylococci infections.	Oxazocilline,Penicillin, Methylphenylisoxazolyl,Sodium Oxacillin,Oxacillin Sodium,Oxacillin, Monosodium Salt, Anhydrous,Oxacillin, Monosodium Salt, Monohydrate,Prostaphlin,Methylphenylisoxazolyl Penicillin,Oxacillin, Sodium,Sodium, Oxacillin
D010397	Penicillanic Acid	A building block of penicillin, devoid of significant antibacterial activity. (From Merck Index, 11th ed)	Acid, Penicillanic
D002969	Clavulanic Acids	Acids, salts, and derivatives of clavulanic acid (C8H9O5N). They consist of those beta-lactam compounds that differ from penicillin in having the sulfur of the thiazolidine ring replaced by an oxygen. They have limited antibacterial action, but block bacterial beta-lactamase irreversibly, so that similar antibiotics are not broken down by the bacterial enzymes and therefore can exert their antibacterial effects.	Acids, Clavulanic
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
D000078142	Tazobactam	A penicillanic acid and sulfone derivative and potent BETA-LACTAMASE inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria.	Tazobactam Sodium,YTR 830,YTR 830H,YTR-830,YTR830
D000900	Anti-Bacterial Agents	Substances that inhibit the growth or reproduction of BACTERIA.	Anti-Bacterial Agent,Anti-Bacterial Compound,Anti-Mycobacterial Agent,Antibacterial Agent,Antibiotics,Antimycobacterial Agent,Bacteriocidal Agent,Bacteriocide,Anti-Bacterial Compounds,Anti-Mycobacterial Agents,Antibacterial Agents,Antibiotic,Antimycobacterial Agents,Bacteriocidal Agents,Bacteriocides,Agent, Anti-Bacterial,Agent, Anti-Mycobacterial,Agent, Antibacterial,Agent, Antimycobacterial,Agent, Bacteriocidal,Agents, Anti-Bacterial,Agents, Anti-Mycobacterial,Agents, Antibacterial,Agents, Antimycobacterial,Agents, Bacteriocidal,Anti Bacterial Agent,Anti Bacterial Agents,Anti Bacterial Compound,Anti Bacterial Compounds,Anti Mycobacterial Agent,Anti Mycobacterial Agents,Compound, Anti-Bacterial,Compounds, Anti-Bacterial
D001618	beta-Lactamases	Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.	beta-Lactamase,beta Lactamase,beta Lactamases
D013211	Staphylococcus aureus	Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications.
D013407	Sulbactam	A beta-lactamase inhibitor with very weak antibacterial action. The compound prevents antibiotic destruction of beta-lactam antibiotics by inhibiting beta-lactamases, thus extending their spectrum activity. Combinations of sulbactam with beta-lactam antibiotics have been used successfully for the therapy of infections caused by organisms resistant to the antibiotic alone.	Bétamaze,CP-45899,Combactam,Penicillanic Acid Sulfone,Sulbactam Sodium,CP 45899,CP45899,Sodium, Sulbactam,Sulfone, Penicillanic Acid