Analysis Of Clinical Distribution And Drug Resistance Of The Nosocomial Infection Of Acinetobacter Baumannii

Objective:To analysis pathogen distribution of gram-negative bacilli in nosocomial infections from Jan 2008 to Dec 2013 in the first hospital affiliated Bao- Tou medical college; To analysis the result of clinical distribution and epidemical specific and anti-biotic susceptibility and of Acinetobacter baumannii;To detect the OXA-23 and OXA-24carbapenemase-encoding drug resistance correlated gene of Acinetobacter Baumannii; To explore the usual pathogen and its resistance and the mechanisms of drug-resistance.Methods:1 Clinical specimen in infection site(Sputum, wound secretions, urine, cerebrospinal fluid,pleural effusion,et. al) were collected from the patients suffering from nosocomial infections during six years. The pathogen species were determined by bacterial cultivation and identification, especially the gram-negative bacilli pathogen species(Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia Coli, Klebsiella spp Coli, Haemophilus influenzae, et. al).2 Focus on analysis of drug resistance in acinetobacter baumannii infection site and distribution department Adopt the K-B agar diffusion method, carry on the anti-biotic sensitive test to the identified as acinetobacter baumannii strains, then, a statistical analysis on the distribution characteristics and vicissitudes of drug resistance of clinical isolated acinetobacter baumannii bacteria in our hospital.3 The drug resistance to the imipenem against the acinetobacter baumannii were increased year by year, therefore, OXA-23 and OXA-24 gene of these resistant strain were detected by polymerase chain reaction(PCR).Results：1 648 gram-negative bacilli strains were examined among the patients suffering from nosocomial infections, 241 strains Pseudomonas aeruginosa, accounted for 37.19%, 162 strainsAcinetobacter baumannii, accounted for 25.00%, compared with other gram-negative bacilli bacteria, there are significant differences(P<0.05).2 162 strains of acinetobacter baumannii strains were obtained from Sputum, wound secretions, urine, cerebrospinal fluid, pleural effusion, et. al. sputum accounted for70.99%, wound secretions accounted for 20.37 %, Other accounts for 8.73%, so, compared with other Clinical specimen, there are significant differences(P<0.05). Most of the patients suffering from nosocomial infections were distributed in neurosurgery department(39 strains), ICU(32 strains) and respiratory(19 strains). 18 acinetobacter baumannii strains were high resistance to 13 kinds of antibiotic, reaching more than 65%, and even some antibiotics above 90%, including amikacin, aztreonam, ciprofloxacin, piperacillin, piperacillin/tazobactam, gentamycin, Ticarcillin/clavulanic acid potassium, cefepime, cefoperazone, cefotaxime sodium, ceftazidime, tobramycin, but for imipenem/cilastatin sodium, cefoperazone/sulbactam, Levofloxacin, resistance tothem is respectively 0%,5.9%, 44.4%. However, The three kinds of antibiotic resistance against acinetobacter baumannii also showed a trend of rising year by year,especially imipenem/cilastatin sodium and Levofloxacin. The resistance of imipenem/ cilastatin sodium was up to 65.9%, Levofloxacin was up to 80.00%, compared with 2008, there are significant differences(P<0.05). Only cefoperazone/ sulbactam has no change. After a summary, there were 60 acinetobacter baumannii strains esistance to imipenem/cilastatin.3 The genes of OXA-23 and OXA-24 were identified in 47 of the 60 acinetobacter baumannii strains,accounted for 78.3%,OXA-24 gene was identified in 3 of the 60 acinetobacter baumannii strains,accounted for 5%,but the above two gene was not identified in 3 susceptible strains.Conclusion:When Respiratory system infection and trauma wound infection occurred, Results: Common pathogens were Pseudomonas aeruginosa, Acinetobacter baumannii, especially Acinetobacter baumannii rate was becamed higher and higher.The drug sensitive test results indicate antibiotic resistance spectrum scope and resistance ratio gradually increased year by year, especially to imipenem/cilastatin, so, the clinicianbe obliged to concern the change antibiotic resistance spectrum for Acinetobacter baumannii nosocomial infections. Production of OXA-23 and OXA-23 formed Carbapenemases, is able to hydrolyze imipenem antibiotic, may be leads to the formation of antibiotic resistance.