| Object: Application colistin, tigecycline, and Biapenem plus sulbactam invivo antibacterial experimental observation of cyclophosphamide causeimmune suppression in vivo antibacterial activity of the state SD rats MDRAcinetobacter baumannii pneumonia model and efficacy, to explore optionsfor treatment of MDR Acinetobacter baumannii infection antibiotic.Method: First of cyclophosphamide in SD rats, the animals areimmunosuppressed, and then establish the immunosuppressive state SD ratsXDR Acinetobacter baumannii pneumonia model. Application colistin,tigecycline and Biapenem plus sulbactam treatment for the infected rats, byobserving the rats survival time and mortality, lung histopathological changes,colony count of lung tissue and serum inflammation factor differences, to testthe effects of different antibiotic regimens on MDR Acinetobacter baumanniiinfections.Results:1General present of the experimental animals All groups of experimentalanimals after cyclophosphamide injection and inoculated eated less water,weight loss, activity poor, hair huddled erect, conjunctival secretions increased,loose stools such as performance. Each group had different levels of mortality,mortality ranged between37.5%~50.0%. The mortality had no statisticallysignificant differences between each group and strain Ab107,Ab309.2Rat lung tissue pathological changes in the lung tissue After HE stainingit was showed widen alveolar septum, varying degrees of congestion, edema,visible small amount of inflammatory cells in the alveolar exudate.Inflammatory changes mainly realized interstitial pneumonia. Strain Ab107and Ab309between the intervention and control groups of various antibiotics, inflammatory changes was no significant difference.3Rat lung tissue colony counts analysis of strain Ab107Compared withthe control group, all treatment groups in lung tissue homogenates colonycounts decreased to some extent. Which colony counts drop of a statisticallysignificant (9.08±0.09vs7.22±0.66, P=0.046) for tigecycline. ForBiapenem plus sulbactam group, compared with the control group the the lunghomogenates colony counts decreased, but there was no statisticallysignificant difference. Colistin group in lung homogenates colony countscompared with the control group had no significant decline. Strain Ab309,compared with the control group, tigecycline treatment group lung tissuecolony counts visible decline, but not yet constitute a statistically significantdifference (8.94±0.20vs7.36±0.41P=0.186). Sulbactam plus Biapenemgroup and colistin group in lung homogenates colony counts compared withthe control group had no significant decline.4Enzyme-Linked Immunosorbent Assay (ELISA) Determination of ratswith48-hour serum inflammatory cytokine TNF-α and MIP-2value. Visibleinoculated Ab107and Ab309two groups in the control group compared to thecontrol group of Ab107TNF-α and MIP-2measured results were higher thancontrol group of Ab309, with a significant statistical difference（TNF-α41.19±13.88vs25.39±10.48P＜0.05；MIP-2858.5±82.5vs730.4±70.4P＜0.05). In Ab107inoculated groups, control group shown higher TNF-α levelcompared to corresponding antibiotic treatment group on behalf of plustigecycline treatment group, but did not constitute a significant difference.Other treatment group, TNF-α and MIP-2measurement results, compared withthe control group hadn’t significant decline. For strain Ab309, compared tothe control group, the antibiotic treatment group showed no significanteffective.Conclusion: In vitro susceptibility prompted tigecycline sensitive strains onlyplay a bacteriostatic effect in experimental animals models; colistin in vitroagainst Acinetobacter maintained a high degree of sensitivity rate, but in theexperiment the animals no antibacterial effect; Carbapenems plus sulbactam only play a marginal inhibitory effect of low levels of drug-resistant strains, ofcarbapenem highly resistant strains its antibacterial effect is not obvious. Pureanti-infection treatment can not improve lung histopathology, reduce mortalityand control of systemic inflammatory response. |
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