Study On Distribution And Resistance Of Acinetobacter Baumannii In Wuhan Union Hospital，2009to2012

Background and ObjectivesBacterial resistance has been a problem of global concern in recent years,especially with the widespread using of antibiotics bacterial, bacteriadisplaying ever-increasing rates of resistance. MRSA was found in1960,VRSE was found in1990. The super bacteria was found in2010, also namedas producing NDM-1drug-resistant bacteria. The bacteria can carry NDM-1gene, encoding New Delhi metallo-beta-lactamase type I. This bacteria isresistant to majority of antibiotics (tigecycline, polymyxin except). In thesame year China also reported the detection of three cases of super bacteria,two cases of feces enterococci and one Acinetobacter baumannii. EuropeanJournal of Clinical Microbiology and Infectious Diseases Society analyzedthat there will no antibiotics can destroy the bacteria carrying the NDM-1genefor at least ten years.There are not too many reports about infections caused by Acinetobacterbaumannii in early years. In recent years the detection rates of Acinetobacterbaumannii is rising in the world, and from a single drug resistance tomultidrug-resistance, low resistance to high resistance, emerging MDRAB(Multidrug-resistant Acinetobacter baumannii) and PDRAB (Pandrug-resistant Acinetobacter baumannii), especially with the appearance of CRAB(carbapenem-resistant Acinetobacter baumannii) in recent years, increased thedifficulty of the treatment, which named as Gram-negative MRSA.Acinetobacter baumannii has a strong vitality, which can survive in thehospital for a long time and cause cross-infection in hospitals easily, led to theoutbreak, so there is needed to enhance the study on Acinetobacter baumannii.Because of the different regions at different medical levels, clinical antibioticselection is also different, lead to regional difference of bacterial resistanceeventually. Therefore, we should master the epidemiological characteristicsand the trend of drug resistance in our region, which can guide clinicians touse of antibiotics rationally, prevent bacterial resistance and controlnosocomial infection, those have important practical significance.Materials and methodsAll kinds of specimens collected in Wuhan Union Hospital from January2009to December2012, accepted by the bacteria room wards from inpatientsand outpatients. Cultivation and isolation was operated with the methodsdescripted by the National Clinical Laboratory Operational Regulation.Susceptibility of3613strains of Acinetobacter baumannii to15kinds ofcommon antimicrobial agents was detected by K-B methods. The resistant rateof bacteria according to the guidelines of CLSI, all dates were analyzed withWHONET5.0software which were provided by monitoring network ofbacterial resistant in World Health Organization and SPSS17.0. Analyzed andmapping using Microsoft Excel software. The epidemiological characteristicsand drug resistance in Wuhan Union Hospital of Acinetobacter baumanniifrom2009to2012were analyzed by descriptive epidemiological methodsretrospectively. Resultsâ’ˆ3613strains of Acinetobacter baumannii were isolated from clinicalsamples from January2009to December2012. The isolation rate of A.bamuannii from gram-negative bacteria is in the first place. Most of A.baumannii were separated from sputum (77.36%,2797/3613), followed bysecretion (6.06%), ascites (2.63%), blood (2.24%), drainage (1.47%), urine(1.05%) and so on.â’‰Acinetobacter baumannii strains were mainly distributed in the ICU(37.50ï¼…,1355/3613), then followed by neurosurgery (14.39ï¼…,520/3613)and cardiac surgery (11.10ï¼…,401/3613). The average age of patients was54.1years old, the ratio of male to female was2.9:1. Acinetobacter baumanniiinfections can occur in the whole year, the peak infection time is not exactlythe same in every year. Infection occurs in the winter and spring relativelyhigher.â’ŠVitro susceptibility results showed that:Acinetobacter baumanniipresents aserious drug-resistant and multi-drug resistant. Minocycline (67.6ï¼…susceptibility in2009,29.1ï¼…susceptibility in2010,33.3ï¼…susceptibility in2011,18.5ï¼…susceptibility in2012) is the most active agents against A.baumannii, Amikacin is the most active agents in2011(21.4ï¼…susceptibility).The resistant rate of minocycline and cefoperazone-sulbactam were lowestrelatively, the intermediate of cefoperazone-sulbactam (21.6ï¼…intermediate in2009,28.4ï¼…intermediate in2010,17.6%intermediate in2011,21.8%intermediate in2012) was highest. Resistance to carbapenem antibiotics rateof about80ï¼…, and the drug resistant rate of other antibiotics was above80ï¼….Conclusion The isolation of A. baumannii increased year by year, and the resistance toantimicrobial agents is increasing, strains represented severe multiple-resistance. Acinetobacter baumannii cause lower respiratory tract infectionmainly, and distributed in the ICU, followed by operation department,Respiratory Medicine, Neurology, Geriatrics. Patients with low immunity,serious basic disease, surgery and mechanical ventilation are risk factors forAcinetobacter baumannii infections.