Liječnički vjesnik, Vol. 134 No. 5-6, 2012.
Original scientific paper
COMPARATIVE URINARY BACTERICIDAL ACTIVITY OF ORAL ANTIBIOTICS AGAINST GRAM-POSITIVE PATHOGENS
Branka Bedenić
Ana Budimir
Ana Gverić
Vanda Plečko
Jasmina Vraneš
Marina Bubonja-Šonje
Smilja Kalenić
Abstract
In routine bacteriological laboratories the antibacterial activity of antibiotics is determined by in vitro testing, usually by disk-diffusion test. However, in vitro testing does not always reflect antibacterial efficiency of antibiotics in vivo. In this investigation, the urine samples obtained in a single oral dose pharmacokinetic study were examined for their bactericidal activity against a range of relevant Gram-positive urinary tract pathogens. Urinary bactericidal activity of linezolid had been previously compared with ciprofloxacin but not with other oral antibiotics such as b-lactams. Linezolid showed satisfactory urinary bactericidal titres throughout the whole testing period against all Gram-positive cocci. Fluoroquinolones displayed high and persisting levels of urinary bactericidal activity against staphylococci, but their activity against enterococci was weaker. According to the results of ex-vivo testing amoxycillin could be recommended only for infections caused by E. faecalis. Amoxycillin combined with clavulanic acid can be considered as a therapeutic option for infections caused by S. saprophyticus and E. faecalis. Older cephalosporins had high titres only against S. saprophyticus. Their drawback is a short elimination half-time in urine resulting in rapid decrease of urinary bactericidal titers during dosing interval. Furthermore, they do not show activity against enterococci due to their intrinsic resistance to cephalosporins.
Keywords
Gram-positive bacterial infections – microbiology, drug therapy; Urinary tract infections – microbiology, drug therapy; Gram-positive bacteria – drug effects; Anti-bacterial agents – therapeutic use, pharmacology, urine; Ciprofloxacin – therapeutic use, pharmacology, urine; Oxazolidinones – therapeutic use, pharmacology, urine; Administration, oral
Hrčak ID:
172421
URI
Publication date:
25.6.2012.
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