Inhibition of bacterial adhesion by subinhibitory concentrations of antibiotics.
BACKGROUND
Urinary Tract Infections (UTIs) due to Escherichia coli is one of the most common diseases encountered in clinical practice. Most common recognised pathogenic factor in E.coli is adhesion. There is accumulating evidence that through subinhibitory concentrations (sub-MICs) of many antibiotics do not kill bacteria, they are able to interfere with some important aspects of bacterial cell function.


METHODS
A study was conducted to investigate the effect of sub MICs (1/2-1/8 MIC) of ciprofloxacin, ceftazidime, gentamicin, ampicillin and co-trimoxazole on E. coli adhesiveness to human vaginal epithelial cells using three strains ATCC 25922, MTCC 729 and U 105.


RESULTS
The 1/2 MIC of all the antibiotics tested produced the greatest inhibition of bacterial adhesion. Morphological changes were observed with ciprofloxacin, ceftazidime and ampicillin at 1/2 MIC and to a lesser extent at 1/4 and 1/8 MIC. Co-trimoxazole caused the greatest suppression of adhesion at 1/2 MIC of E. coli strain MTCC 729 when compared with the controls, followed by ceftazidime.


CONCLUSIONS
These results suggest that co-trimoxazole is the most effective antibiotic in the treatment of urinary tract infections caused by uropathogenic E. coli.
Vidya
K C
KC
Department of Microbiology, Kasturba Medical College, Manipal, India.
Mallya
P S
PS
Rao
P S
PS
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects*; D002939:Ciprofloxacin / Q000494:pharmacology; D004847:Epithelial Cells / Q000382:microbiology; D004926:Escherichia coli / Q000502:physiology*; D005260:Female; D006801:Humans; D008826:Microbial Sensitivity Tests; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination