Each measurement was repeated three times. Ethidium
bromide accumulation assay The assay was modified as described previously [38]. Briefly,H. pylori were grown on Columbia SB431542 supplier blood agar plate for 48 h. Then, bacteria were pelleted and washed twice with ice-cold 50 mM potassium phosphate (pH 7.0) containing 5 mM MgSO4. Cells were resuspended in 1 ml of potassium phosphate Selleck GSK2126458 buffer (pH 7.0) at an optical density (OD600) of 0.5. Cells were preloaded with 10 μg/ml ethidium bromide. At the 12-min time point, 10 μM of CCCP was added to the cells suspensions to assess energy-dependent efflux. CCCP was not added to the cells served as a control. The selleck increase
in ethidium bromide fluorescence intensity was measured in a Gemini XPS spectrofluorimeter at 30°C with excitation at 500 nm and emission at 580 nm. Each measurement was repeated three times. Statistical analysis For all experiments, a P value of < 0.05 was considered indicative of statistical significance, and all statistical analyses were determined with Student's t test. Results The MICs for glutaraldehyde in clinical isolates H. pylori strains were harvested during endoscopic examinations at National Taiwan University Hospital from 1991 to 2000 [39]. 49 clinical isolates filipin were cultured successfully from stock and stored at -80°C. The patients from which these strains were isolated suffered from gastritis (15 strains), duodenal ulcer (16 strains), gastric ulcer (9 strains), mucosa-associated lymphoid tissue lymphoma (MALToma) (3 strains),
and gastric cancer (6 strains). Subsequently, the MICs of glutaraldehyde were determined for these strains. The MICs of glutaraldehyde for most of the clinical isolates were the range of 3–6 μg/ml glutaraldehyde (Fig. 1). However, the diseases caused by the strains of H. pylori and the MICs of glutaraldehyde in these clinical isolates were not correlated (Table 1). Figure 1 The MICs of glutaraldehyde in clinical isolates from National Taiwan University Hospital. Table 1 The MICs of glutaraldehyde in clinical isolates during 1991–2000. Disease Number of isolates The MICs of glutaraldehyde in isolates (numbers) Gastritis 15 7 μg/ml (n = 2), 6 μg/ml (n = 1) 5 μg/ml (n = 3), 4 μg/ml (n = 4) 3 μg/ml (n = 5) Duodenal ulcer 16 10 μg/ml (n = 1), 7 μg/ml (n = 1) 6 μg/ml (n = 2), 5 μg/ml (n = 3) 4 μg/ml (n = 5), 2 μg/ml (n = 2) 1.5 μg/ml (n = 1), 1 μg/ml (n = 1) Gastric ulcer 9 10 μg/ml (n = 1), 7 μg/ml (n = 1) 6 μg/ml (n = 3), 5 μg/ml (n = 1) 3 μg/ml (n = 1), 1.