小檗碱对小鼠感染犊牛源生物被膜阳性、多重耐药大肠杆菌的体内抑菌作用

Inhibitory effect of berberine on mouse infected calf derived biofilm positive and multi drug resistant Escherichia coli in vivo

为阐明小檗碱对小鼠感染犊牛源生物被膜阳性、多重耐药大肠杆菌的体内抑菌作用,试验采用微量肉汤稀释法确定41株分离株的MIC值;采用改良结晶紫染色法,确定其生物被膜形成能力;采用ELISA法检测小鼠血清中IL-1β、IL-6、TNF-α的含量;采用血常规检测小鼠血液中白细胞、淋巴细胞、中性粒细胞数目及血红蛋白含量。结果显示:分离菌株对四环素、氨苄西林、甲氧苄啶、磺胺嘧啶耐药率较高,对阿米卡星、米诺环素、头孢西丁较为敏感;生物被膜形成能力无、弱、中、强的菌株数分别为14、10、7、10株;生物被膜阳性大肠杆菌耐10种以上药物的菌株占比73.9%,且多重耐药菌株占比66.7%;生物被膜强阳菌株中的多重耐药菌株占比80%;小檗碱高、低剂量组及联合给药组可不同程度降低小鼠血清中促炎因子的含量,降低血液中白细胞、淋巴细胞、中性粒细胞数目,并升高血红蛋白浓度。犊牛源大肠杆菌形成生物被膜可增强自身多重耐药性,且小檗碱具有成为临床治疗由生物被膜阳性、多重耐药大肠杆菌引起的犊牛腹泻病药物的潜力。

In order to clarify the in vivo antibacterial effect of berberine on biofilm-positive multidrug-resistant E.coli from mouse infected calf,the MIC values of 41 isolates were determined by broth dilution method.The ability of biofilm formation was determined by improved crystal violet staining.The contents of IL-1β,IL-6 and TNF-αin serum of mice were determined by ELISA.The number of white blood cells,lymphocytes,neutrophils and hemoglobin content in the blood of mice were detected by routine blood tests.The results showed that the isolates had high drug resistance to tetracycline,ampicillin,trimethoprim and sulfadiazine,and were sensitive to amicacin,minocycline and cefoxitin.The number of strains with no,weak,medium and strong biofilm formation ability was 14,10,7 and 10,respectively.The proportion of biofilm-positive E.coli strains resistant to more than 10 drugs was 73.9%,and the proportion of multi-drug resistant strains was 66.7%.Multidrug-resistant strains accounted for 80%of biofilm positive strains.The content of proinflammatory factors in serum,the number of white blood cells,lymphocytes and neutrophils in blood,and the concentration of hemoglobin were decreased in berberine high-dose,low-dose and combined administration groups.The formation of biofilm of calf E.coli could enhance its own multiple drug resistance,and berberine had the potential to be a clinical treatment for calf diarrhea caused by biofilm positive and multiple drug resistance E.coli.