Infection Characteristics Of Chronic Mountain Sickness (CMS) Rabbit Limbs With Explosive Injury

OBJECT:The purpose of the experiment is to simulate a high altitude environment,and create a model of CMS animal limb explosive injury.And then,research the characteristics of infection,the bacterial species and antimicrobial susceptibility situation.Methods:24 New Zealand white rabbit were randomly divided into plateau(n=12)and plain(n=12)groups.Two groups,respectively feeding into the low pressure tank and the plain environment for 30 days.The two groups of animals are all should be tested the hemoglobin(Hb).When the group of plateau animal Hb value > 21 g/d L.It means that we have succeed obtained the animals of CMS.Two groups of animals in time of different nodes to observe wound infection after injury.And get within the organization of the wound for bacteria counting,authenticate the bacterial species and antimicrobial susceptibility situation.Result:1?Low pressure tank animals feeding after 30 days,Hb values are significantly high-er than plain group.And the Hb average value is 22.78±1.64 g/d L.2?The bacterial amount of wound in plain group was 10 times higher than the plateau group.3?The time of bacterial settling down was 8 to 12 hours after injury in plateau group and 0-4 hours in plain group.4? From complete the bacteria to colonize to a wound infection after injury,plain group took 4 hours and plateau group took up to 24 hours.5? In plain group,the critical amount of bacterium that caused wound infection was 105 cfu per gram wet tissue,and the time concentrated of infection was 8-12 hours after injury,while in plateau group,the critical amount of bacterium was 107 cfu per gram wet tissue,respectively,and the time concentrated of infection was 36-48 hoursafter injury.6? Plateau wound infection bacteria respectively are Staphylococcus aureus,Staphylococcus epidermidis,Enterococcus and Bacillus coli.And the plain group are Bacillus coli,Pseudmonas aerugionosa,Klebesiella pneumoniae,Staphylococcus aure-us and Enterococcus.7 ? The drug resistant rate of Gram stain negative bacteria to ampicin,piperacillin,cefuroxime,ciprofloxacin were above 50%.But imipenem and aztreonam still kept good sensitiviy with drug resistant rate was zero.Almost all gram stain positive cocci to penicillin,erythromycin resistant,only teicoplanin and vancomycin is sensitive to all strains.Conclusion:1 ? Plateau blast injury wound bacterial contamination is lighter plain.2 ?Plateau bacteria breeding is slower than plains,infections occur later plains,and the critical amount of bacterium that caused wound infection significantly higher than that of plains.3?Blast injury infection bacteria in plateau area are mainly composed of gram positive coccus(SA).Oppositely,in plain area are mainly composed of Gram stain negative bacteria(EC).4 ?These two types of bacteria for clinical has a high resistance to commonly used antibiotics.Therefore,should understand the characteristics of the resistance of each species,rational use of antimicrobial agents.So can we improve the cure rate of infection of explosive wound in high altitude.