The Study On Resistance Of 95 Carbapenem Non-susceptible Acinetobacter Baumannii

Background and Objectives:The Acinetobacter spp.belong to Neisseriaceae,extensively distributed at the nature and the hospital surroundings.Acinetobacter baumannii,the most frequent Acinetobacter spp, is the important pathogenic bacterium of nosocomial infection,and can cause serious even lethality infection in hypoimmunitious patient,such as the ventilator-associated pneumonia(VAP),sepsis,urinary system infection and meningitis etc.In recent years,the noscomial infection caused by Carbapenem non-Susceptible Acinetobacter baumannii(CNSAB) was increased,which make the clinician face a huge challenge.This research invested the epidemiology and drug resistant reason of CNSAB,Based on the determination of the resistant spectrum of antibiotics,the strains was analyzed by polymerase chain reaction(PCR),gene sequencing and homogenous analyzing.The study was expected to be able to provide the basis for the appropriate use of antibiotics to control the nosocomial infections ofAcinetobacter baumannii.Methods:Retrospective consulted the medical records of the 95 patients infected CNSAB between 2001 and 2007 in Henan Province People's Hospital,retrospective analysis were conducted for the drug resistance and the distribution of the clinical wards in the 95 CNSAB. 26 non-repetitive clinical CNSAB isolates between May and December 2007,was examimed by E-test and the three dimensional test to detect carbapenemase production.Specific primers corresponding to genetic sequences of different oxa type carbapenemase were designed,and the 26 isolates was determined by random amplified polymorphic DNA (RAPD).The PCR products were sequenced and homogenous analyzed compared to the known oxa type carbapenemase gene counterparts reported in genebank.ResultsThe susceptibility of 95 non-repetitive Carbapenem non-Susceptible Acinetobacter baumannii(CNSAB) strains to cefotaxirr/e and other cephalosporin were 0 and 11.5%to 25%respectively,Quinolinones 21.9%to 29%,Amikacin 15.6%,minocycline 22.2%and Cefoperazone/Sulbactam 59.4%which was the best susceptibility.The specimens which isolated CNSAB were sputum,pus liquid,blood respectively,and the wards were Pneumology Department,Intensive Care Unit,Neurosurgery Department.A clone,B clone,C clone,D clone and E,F,G,H,I clone were isolated in Henan Province People's Hospital. blaoxa-23s and blaoxa-58 were detected from ten(38.5%) and one strains(3.8%),blaVIM-, blalMP- and blaoxa-24 were not detected in 26 CNSAB strain.Conclusions:The prevalent CNSAB strains were multiresistant,cefoperazone/sulbactarn may be a good and safe therapeutic option to treat severe nosocomial infections caused by these stains. This study showed that Carbapenems-Non-susceptible clone spread was the main reason for the increasing carbapenem resistance trend in Henan Province People's Hospital.Epidemic carbapenem resistant clones were isolates among the different department.The irrational using of antibiotic was the major factor about the nosocomial infection.For this reason,the study to the drug resistance rationale of bacteria is very important.This research imply that the most prevalent carbapenemase was OXA-23 carbapenemase in the non-repetitive clinical isolates of 26 CNSAB in Henan Province People's Hospital.As we best known,this is the first report of producing OXA-58 type carbepenemase in A.baumannii isolates in Henan province.