ABSTRACT
Objective To establish a bioiflm (BF) models of Haemophilus inlfuenza in vitro, and to observe the changes of antibiotic susceptibility after the BF fromation. Methods Thirty strains Haemophilus inlfuenzae isolated from adenoids of children with adenoidal hypertrophy and cultured in a 96-well plate. The BF was identiifed by crystal violet staining and scanning electron microscopy (SEM). The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and the minimum bioiflm bacteria bioiflm clear concentration (MBEC) of ampicillin (AMP), ceftriaxone (CRO), levolfoxacin (LVFX) and azithromycin (AZM) were individually detected. Result All of 30 strains of Haemophilus inlfuenzae formed various BF. After BF is formed, the increase of MBEC for different antibiotics was inconsistent with the increase of MIC and MBC. The difference was statistically signiifcant (MBEC/MBC, H=91.54;MBEC/MIC, H=87.91;all P<0.001). The MBEC of AMP was the highest, up to 100 times than the MBC and MIC. The MBEC of CRO was dozens of times than the MBC and MIC. The MBEC of LVFX and AZM were most close to those of MBC and MIC. Conclusion After the formation of BF, resistance to antibiotics of Haemophilus inlfuenzae is enhaced. LVFX and AZM showed more favorable effect on Haemophilus infuenzae BF.
ABSTRACT
Objective: To assay minimal biofilm eradication concentration (MBEC) of various extraction compounds from Galla Chinensis to 5 oral bacterial biofilms, and then to set up traditional Chinese medicine empirical study methods of pharmacodynamic susceptibility. Methods:5 cariogenic bacteria strains were selected (Streptococcus mutans ATCC25175, Streptococcus sanguis ATCC10556, Lactobacillus rhamnosus AC413, Actinomyces naeslundii WVU627, Actinomyces viscosus ATCC19246) in present study. Various extraction compounds of Galla Chinensis were GCE (aqueous extract), GCE-B(300 ml/L alcohol extract), GCE-C(500 ml/L acetone extract),GCE-D(1 000 ml/L acetone extract), gallic acid and methyl gallate. ①Observed oral bacterial biofilm formation in MBECTM-Device at different-time-stages. ②MBECTM -HTP-Assay:The minimal inhibitory concentration (MIC) and minimal biofilm eradication concentration (MBEC) of various extraction compounds of Galla Chinensis on 5 oral bacteria strains were determined. Results:5 oral bacterial biofilm were readily formed on the lid of MBECTM-Device under selected condition (observed by SEM). 5 oral cariogenic bacteria growing as planktonic populations were sensitive to 6 extraction compounds of Galla Chinensis. When compared to 6 extraction compounds of Galla Chinensis, 5 oral cariogenic bacterial biofilm were 2-16 times less susceptible than growing planktonic bacteria. GCE and GCE-B are the most effective medicine against 5 oral cariogenic bacterial biofilm. GCE-C and GCE-D were effective in killing oral-bacterial biofilm at relatively high concentration, but gallic acid and methyl gallate were less effective.Conclusion:GCE and GCE-B are the most effective medicine against 5 oral cariogenic bacterial biofilm of 6 extraction compounds from Galla Chinensis. MBEC can provide a relatively accurate medicine concentration for clinical test.