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. MATERIALS AND 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. CONCLUSION: These results suggest that co-trimoxazole is the most effective antibiotic in the treatment of urinary tract infections caused by uropathogenic E. coli.

A microbiological study of ophthalmia neonatorum in hospital-born babies.

A retrospective microbiological analysis of ophthalmia neonatorum among the hospital-born babies of a rural multispecialty hospital over a period of 2 years was made. Diagnostic cultures were performed in all the affected babies and 30 cases were found to be culture positive for bacterial species. The spectrum of various bacterial isolates and their antibiotic sensitivity patterns were studied. Pseudomonas aeruginosa was found to be the commonest causative organism according to this study and newer fluoroquinolones like ciprofloxacin and norfloxacin were the antibiotics that showed the best sensitivity pattern.