Susceptibility testing of 96 clinical group IVe isolates to 19 antimicrobial agents by agar dilution revealed that, at drug levels achievable in serum, the isolates were susceptible only to aminoglycosides, cephalosporins, and colistin, whereas at drug concentrations attainable in urine, they were susceptible to erythromycin, tetracycline, and nitrofurantoin as well.

BACKGROUND TR-700 is the active moiety of TR-701 (DA-7157), a new oral/intravenous oxazolidinone prodrug. We examined its activity against linezolid-susceptible and -resistant staphylococci and enterococci. METHODS MICs were determined by the CLSI agar dilution method. RESULTS MICs of TR-700 were tightly clustered around 0.5 mg/L for linezolid-susceptible staphylococci and enterococci compa...

The study relates to the theory of diffusion methods for antibiotic sensitivity testing. The aim of the study was to show the relationship between the antibiotic critical concentration (Cc) and its minimum inhibitory concentration (MIC). The results contribute to the explanation of the Etest's reliability and support the scientific basis for MIC determination using agar diffusion methods. Susce...

The antibacterial activity of trimethoprim-sulfamethoxazole against 99 strains of Staphylococcus epidermidis was tested on media known to be low in thymidine content, as determined by screening with Streptococcus faecalis. Eighty-one percent of the isolates were susceptible by agar dilution. Trimethoprim-sulfamethoxazole was bactericidal against two strains of S. epidermidis when thymidine phos...

Methods: A total of 347 non-duplicate ESBL-producing E. coli (165) and K. pneumoniae (182) were collected. The fosfomycin MICs were determined by the agar dilution method according to CLSI guidelines. PCR was used to detect the plasmid-encoded fosfomycin resistance genes (fosA, fosA3, fosB and fosC2). For isolates harbouring plasmid-encoded fosfomycin resistance genes, sequence types (STs) were...

The in vitro antistaphylococcal activity of RP 59500, a new streptogramin, was comparable to those of vancomycin and teicoplanin against Staphylococcus aureus, and RP 59500 was the most active agent against coagulase-negative staphylococci. All staphylococcal strains were inhibited by 4 micrograms of RP 59500 per ml, including multiply resistant strains. Broth microdilution and agar dilution te...

for 108 Enterobacteriaceae were 0.25 –1 mg/L (mode 0.5 mg/L) for the susceptible population and 32 to .128 mg/L (mode 32 mg/L) for the resistant population. For the 64 P. aeru-ginosa isolates, the MICs of colistin were 1 – 4 mg/L (mode 4 mg/L) for the susceptible population and 8 – 16 mg/L (mode 8 mg/L) for isolates considered as resistant. When determined by Etest, there was a shift towards 2-...

The aim of this study was to analyze the susceptibility trends to seven antibiotics of Bacteroides fragilis group isolates based on three survey studies performed by the Committee of Anaerobic Bacteria between 1989 and 2002. Fifty three, 82 and 65 B. fragilis group isolates were collected during each period. The antimicrobial agents included were: ampicillin, ampicillin-sulbactam (2:1), cefoxit...

We compared the susceptibility test results of 220 anaerobes against 14 antimicrobials using the Etest (AB Biodisk, Solna, Sweden) with those using the National Committee for Clinical Laboratory Standards (NCCLS) standard agar dilution method (Wadsworth version). The Etest medium was brucella blood (whole) agar and the inoculum size was equivalent to a no. 1 McFarland standard. Thirty-six perce...

Two new monoterpenoids, 8,10-dihydroxy-9(2)-methylbutyryloxythymol (1) and 10-hydroxy-8,9-dioxyisopropylidene-thymol (2), together with five known thymol derivatives: 8,9,10-trihydroxythymol (3), thymol-beta-glucopyranoside (4), 9-hydroxythymol (5), 8,10-dihydroxy-9-isobutyryloxythymol (6), and 8-hydroxy-9,10-diisobutyryloxythymol (7), were isolated from Centipeda minima. Their structures were ...