Diabetic foot infections. Bacteriology and activity of 10 oral antimicrobial agents against bacteria isolated from consecutive cases.

OBJECTIVE: To study the relative frequency of bacterial isolates cultured from community-acquired foot infections and assess their comparative in vitro susceptibility to sparfloxacin, levofloxacin, and eight other commonly used oral antimicrobial agents. RESEARCH DESIGN AND METHODS: This is a prospective study in which the infected wounds of 25 consecutive diabetic patients seen by one of the authors were cultured as they entered the hospital. Isolates were stored and tested for susceptibility to 10 oral antimicrobial agents using the agar dilution method. RESULTS: Staphylococcus aurcus was the most common isolate (76% of patients), including methicillin-resistant S. aurcus (MRSA) in 5 of 25 (20%) patient wounds. Streptococci, enterococci, Enterobacteriaceae, and anaerobes were also present in > or = 40% of patient wounds. Sparfloxacin and levofloxacin were the most active agents tested with activity against > or = 88% of isolates. Isolates resistant to sparfloxacin and levofloxacin included MRSA, enterococci, and some anaerobes. When analyzed by prior exposure to antibiotics, patients who had previously received oral antibiotics were more likely to have MRSA, enterococci, and Pseudomonas aeruginosa isolated and less likely to have Enterobacteriaceae and anaerobes isolated from their wounds. CONCLUSIONS: MRSA and enterococci are now a common cause of diabetic foot infections, and the increased prevalence may be due to antimicrobial use. These wounds may require use of combined antimicrobial therapy for initial outpatient management. The new fluoroquinolones, sparfloxacin and levofloxacin, were the most active oral agents tested.

Comparative in vitro activities of azithromycin, Bay y 3118, levofloxacin, sparfloxacin, and 11 other oral antimicrobial agents against 194 aerobic and anaerobic bite wound isolates.

The activities of sparfloxacin, levofloxacin, Bay y 3118, azithromycin, cefprozil, loracarbef, and nine other oral antimicrobial agents against 194 aerobic and anaerobic clinical bite wound isolates were determined by the agar dilution method. Sparfloxacin, levofloxacin, and Bay y 3118 were active against all aerobic isolates (MICs at which 90% of the isolates are inhibited [MIC90], < or = 1.0 microgram/ml for sparfloxacin and levofloxacin and 0.1 microgram/ml for Bay y 3118) and many anaerobic isolates, with the exception of the fusobacteria. Azithromycin was more active than erythromycin by 1 to 2 dilutions against many aerobes, including Pasteurella multocida and Eikenella corrodens, and by 2 to 4 dilutions against anaerobic isolates. Cefprozil was more active (MIC90, < or = 1 microgram/ml) than loracarbef (MIC90, < or = 4 micrograms/ml) against aerobic gram-positive isolates, but both had poor activity (MIC90, > or = 16 micrograms/ml) against peptostreptococci. Both cefprozil and loracarbef had MIC90s of < or = 0.5 micrograms/ml against P. multocida.

Development and evaluation of a blood-free medium for determining growth curves and optimizing growth of Rochalimaea henselae.

Two strains of Rochalimaea henselae were used to optimize a blood-free growth medium. Seven agar bases, four broths, and combinations of eight supplements were evaluated. Acceptable growth was achieved in media containing Fildes solution and hemin, with the best growth demonstrated in brucella broth or on brucella agar with 6 to 8% Fildes solution and 250 micrograms of hemin per ml. R. henselae utilized hemin in concentrations six times that utilized by Rochalimaea quintana. Erythrocyte membrane was necessary to achieve the full growth-promoting effect of rabbit blood.