Mechanisms Of Multi-drug Resistant Acinetobacter Baumannii (AB)to Aminoglycosides And Exploring Of Bacteriostatic Efficacy Of Chinese Herbal Medicine

Objective:1. Explore on the drug resistance and its mechanism of Acinetobacter baumannii (AB) to aminoglycoside antibiotics.2. Analyze effects of ethanol-extracts of20common herbs to11kinds of multiple drug-resistant bacteria which are common in Clinic. Explore the feasibility of Chinese herbs for bacteriostasis and its possible mechanisms by observiag antibacterial activity in vitro.Methods:1. Analysis drug sensitivity of71MDR acinetobacter baumannii by VITEK;2. Study the plasmid related drug resistance genes (aacCl、aacC2、aacC3、aacA4、 aadA1、aadA2、aacA7、armA1and armA2) by way of polymerase chain reaction (PCR);3. Find out possible gene mutations through sequencing;4. Screen for Chinese herbs which have good effect on AB;5. Identify of clinical common MDR bacteria and their drug sensitivity by VITEK;6. Detect affects of herbs on MDR bacteria and their MIC.Results:1. Drug resistant rates of AB to Gentamycin, Tobramycin and Amikacin were100%(71/71),73%(52/71) and20%(14/71) respectively,20%of them show resistance to all these three kinds of aminoglycoside antibiotics;2. The positive rate of genotype aaaCl、aacA4、armA、aadA1and armA2were100%(71/71),100%(71/71),84.5%(60/71),98.6%(70/71) and100%(71/71); respectively, but we didn’t find any genotype of aacC2, aacC3, aadA2and aacA;3. The thanol-extract of Galla Chinensis and Coptis chinensis Franch had a strong antibacterial activity, and their bacteriostatic circle were bigger than those of Ampicillin;4. The minimum inhibitory concentration (MIC) of Galla Chinensis and Coptis chinensis Franch were low to0.195and6.25mg/mL respectively.Conclusion:1. Plasmid harboring aacCl, aacA4, armAl, aadA1and armA2genes is one of the mechanisms of multi-drug resistance of MDR AB;2. Galla Chinensis have wide antimicrobial spectrum, it has obvious bacteriostatic effects on clinical common MDR bacteria. It can provide a new reference for the clinical treatment of MDR bacteria infection;3. The extract of Galla Chinensis can inhibit air bacteria to some extent, so it can consider applied to air disinfectant reasearch.