流感嗜血杆菌生物膜形成对抗生素的耐药性变化

Biofilms produced by Haemophilus influenzae in vitro and antibiotics sensitivity changes

目的体外建立流感嗜血杆菌(Haemophilus influenzae)生物膜(BF),观察细菌形成BF后对抗生素敏感性的变化。方法从腺样体肥大患儿的离体腺样体组织中分离30株流感嗜血杆菌,并以96微孔板培养,采用结晶紫染色和扫描电镜(SEM)鉴定BF形成;分别测定氨苄西林(AMP)、头孢曲松(CRO)、左氧沙星(LVFX)和阿奇霉素(AZM)4种抗菌药物浮游菌的最低抑菌浓度(MIC)、最低杀菌浓度(MBC)以及生物膜菌最低生物膜清除浓度(MBEC)。结果 30株流感嗜血杆菌体外都有不同程度BF形成。当BF形成后,不同抗生素的MBEC较其MIC、MBC增高程度大小不一,差异有统计学意义(MBEC/MBC:H=91.54,MBEC/MIC:H=87.91;P均<0.001)。AMP的MBEC最高,可高达MBC和MIC的100多倍;CRO的MBEC较MBC和MIC可增高数十倍,LVFX和AZM对BF的MBEC最接近于MBC和MIC。结论 BF形成后,流感嗜血杆菌耐药性增强;氟喹诺酮类LVFX和大环内酯类AZM对流感嗜血杆菌BF作用相对良好。

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.