The Study Of Post Antibiotic Effect And Its Influence Factors Of Tigecycline

Background and Objective:With the widespread application of antibiotics, especially irrational use of antibiotics has led to the continuous generation and enhancement of bacterial drug resistance. At present,multidrug-resistance pathogenic microorganisms has become the major pathogen in nosocomial infections, take serious threat to human life and safety, and take a tremendous challenge to treatment.Under this background, tigecycline, as a kind of novel glycylcycline antibiotics, was approved in 2005 in American, it has received the extensive concern after the listing because of its broad-spectrum antibacterial activity, especially has very high activity on common drug resistant bacteria. In this study, through the research of in vitor postantbiotic effect of multidrug-resistant acinetobacter baumannii(MDR-AB).methicillin-resistant Staphylococcus aureus(MRSA). extended-spectrum beta-lactamases(ESBL)producing Escherichia coli and standard strain of E.coli ATCC25922 produced by tigecycline and its influence factors, aiming at improving the understanding of the majority of clinicians to the in vitro antibacterial activity of tigecycline, and to provide basis for clinical rational drug use.Methods:In addition to the standard strain of E.coli ATCC25922, the other tested strains were from the First Affiliated Hospital of Dalian Medical University clinical isolates. The minimum inhibitory concentrations (MICs) of the tested strains were determined by microdilution method, determination of tigecycline in vitro PAE by plate colony counting method,.we have study the PAE of all the tested strains under different drug concentrationgs of 1,2.5,5,10 times the MIC respectively, contact 1h or 2h. In addition, through the study of PAE produced by tigecycline combine with cefoperazone sodium and Sulbactam Sodium for injection (sulperazone) to MDR-AB, to observe the influence of drug combination on PAE.Results:The study found, tigecycline can produce PAE against all the tested strains. Tigecycline can produce PAE ranging from 0.5 1h to 2.26h aganist MDR-AB, the average was 0.99±0.61h; produce PAE ranging from 0.57h to 2.03h aganist extended-spectrum beta-lactamases(ESBL)producing E. coli, the average was 1.25 ±0.55h; produce PAE ranging from 1.59h to 4.25h, the average was 2.67±0.88h; at the same time,the PAE of tigecycline against the standard strain ATCC25922 was measured, ranging from 0.66h to 2.68h, the average was 1.53±0.75h.Tigecycline can produce longer PAE against MRSA, compared with MDR-AB, ESBL positive E. coli,standard strain of E.coli ATCC25922, there was a statistically significant difference (P< 0.01), while there were no statistically significant difference between the rest of the tested strains(P> 0.05).In this study, we found the PAE of all the tested strains prolonged with the increased of contace time, to the ESBL positive E.coli, MRSA and ATCC25922, the difference was statistically significant (P< 0.05), but to the MDR-AB, although the PAE is increasing with time prolonged, but there was no significant difference(P> 0.05); the PAE extended with the increase of drug concentration, for the majority of the tested strains,compared the PAE between the different concentrations, the difference has statistical significance(P<0.05). The PAE of Tigecycline,and sulperazone aganist the MDR-AB alone was 0.37,0.73h respectively, while combination,the PAE was 1.23h, this two kinds of antibacterial drag showed additive effect.Conclusion:1. Tigecycline can produce PAE ranging from 0.5 1h to 4.25h aganist MDR-AB, MRSA, ESBL positive E. coli, standard E.coli strain ATCC25922.2. The PAE of Tigecycline against MRSA was significantly longer than that of MDR-AB,ESBL positive E. coli, standard E.coli strain ATCC25922, there was a statistically difference (P<0.05)3. The PAE of Tigecycline against the tested strains extended along with the increase of drug concentration and contact time.4. Tigecycline generates longer PAE against ESBL positive E.coli than E.coli standard strain ATCC25922, but there was no statistical difference between the two groups (P>0.05).5. It shows an additive effect when Tigecycline combined with sulperazone against MDR-AB, prompt that the two antibiotics combination contribute to strengthen the clinical efficacy against MDR-AB.