Effect of sodium hypochlorite on biofilm of Klebsiella pneumoniae with different drug resistance.

ABSTRACT

BACKGROUND: Biofilm formation is a major factor in the resistance mechanism of Klebsiella pneumoniae. This study aimed to evaluate the effects of sodium hypochlorite on the biofilm of K. pneumoniae with different drug resistance. METHODS: We collected 3 different types of K. pneumoniae respectively. The growth trend of biofilms of different drug-resistant K. pneumoniae was quantified by measuring the OD590 for 7 consecutive days using crystal violet staining. Scanning confocal fluorescence microscopy was used to observe biofilm morphology. RESULTS: After adding sodium hypochlorite, there were significant differences between the OD590 value of the 200, 500, and 1,000 µg/mL groups and the positive control group (all P < .05) on the fifth day. Concentrations of 2,000 and 5,000 µg/mL sodium hypochlorite were added after the biofilm had matured. In the 5,000 µg/mL sodium hypochlorite group, the OD590 of K. pneumoniae biofilm in the 3 groups decreased significantly compared with the blank control group (all P < .05). CONCLUSIONS: Sodium hypochlorite inhibited and cleared the biofilm of K. pneumoniae with different drug resistance, and the effect was enhanced with the increase of concentration in the range of bacteriostatic and bactericidal concentration.