Biomaterial Database

[Subinhibitory activity of cefaclor and cephalexin (author's transl)]. 1979

P M Shah, and S Staszewski

The determination of the minimal inhibitory concentration (MIC), which is usually performed after 18 to 24 hours of incubation, results in the case of cefaclor in a false picture of the actual activity. Cefaclor is chemically so unstable that after 24 hours only 2-5% of the substance is microbiologically active. In order to compare the activity of cefaclor and cephalexin, the effect of subinhibitory concentrations of both antibiotics against Escherichia coli and Klebsiella pneumoniae strains was studied by means of turbidimetry. After eight hours the absolute inhibitory concentration of cefaclor was lower than that of cephalexin with both methods. At the same time the effect of subinhibitory concentrations of both antibiotics was equal. Automatic measurement over 20 hours showed at the end of the experiment a higher MIC, and also a higher subinhibitory range, for cefaclor than for cephalexin. In our opinion the absolute inhibitory concentration after eight hours should be the criterion used to evaluate the effectiveness of cefaclor and cephalexin, and not the MIC which is usually used. The eight-hour criterion should also be applied in clinical use.

UI	MeSH Term	Description	Entries
D007709	Klebsiella	A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria whose organisms arrange singly, in pairs, or short chains. This genus is commonly found in the intestinal tract and is an opportunistic pathogen that can give rise to bacteremia, pneumonia, urinary tract and several other types of human infection.
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D002433	Cefaclor	Semisynthetic, broad-spectrum antibiotic derivative of CEPHALEXIN.	5-Thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylic acid, 7-((aminophenylacetyl)amino)-3-chloro-8-oxo-, (6R-(6alpha,7beta(R*)))-,Ceclor,Cefaclor Anhydrous,Cefaclor Monohydrate,Keclor,Lilly 99638,S-6472,S 6472,S6472
D002506	Cephalexin	A semisynthetic cephalosporin antibiotic with antimicrobial activity similar to that of CEPHALORIDINE or CEPHALOTHIN, but somewhat less potent. It is effective against both gram-positive and gram-negative organisms.	5-Thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylic acid, 7-((aminophenylacetyl)amino)-3-methyl-8-oxo-, (6R-(6alpha,7beta(R)))-,Cefalexin,Cephalexin Dihydride,Cephalexin Hemihydrate,Cephalexin Hydrochloride,Cephalexin Monohydrate,Cephalexin Monohydrochloride,Cephalexin Monohydrochloride, Monohydrate,Cephalexin, (6R-(6alpha,7alpha(R)))-Isomer,Cephalexin, (6R-(6alpha,7beta(S*)))-Isomer,Cephalexin, (6R-(6alpha,7beta))-Isomer,Cephalexin, Monosodium Salt,Cephalexin, Monosodium Salt, (6R-(6alpha,7beta))-Isomer,Ceporexine,Palitrex
D004355	Drug Stability	The chemical and physical integrity of a pharmaceutical product.	Drug Shelf Life,Drugs Shelf Lives,Shelf Life, Drugs,Drug Stabilities,Drugs Shelf Life,Drugs Shelf Live,Life, Drugs Shelf,Shelf Life, Drug,Shelf Live, Drugs,Shelf Lives, Drugs
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005188	False Negative Reactions	Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)	False Negative Reaction,Reaction, False Negative,Reactions, False Negative