Clinical Characteristics And Bioinformatics Of Acinetobacter Baumanii Blood Stream Infections

1. Clinical characteristics and drug susceptibility of Acinetobacter baumanii isolated from blood stream (AbBSI); Risk factors for death and clinical outcomes associated with AbBSIObjective:To investigate the clinical characteristics and drug susceptibility of Acinetobacter baumanii isolated from blood stream and to determine the mortality rate associated with blood stream infections by Acinetobacter baumanii.Methods:SAS9.2 and Excel software was used to collect statistics. A matched, retrospective study was conducted between January 2006 and December 2013 in a large, tertiary medical facility. According to the nosocomial infection standard of China and blood stream infection standard of the United States,211 cases were included in the study. These cases were grouped into digestive diseases and non-digestive diseases or into groups treated in the ICU or general wards. The following factors were measured: APACHE Ⅱ scores, clinical outcomes, departments of stay, length of stay, BMI index, primary diagnosis, previous (and after) IMT and antibiotic treatment (carbapenems, third generation of cephalosporins and CPS)and procedures such as surgery, ventilation, and use of catheters, previous (and after) WBC and neutrophils records, and drug susceptibility. Clinical outcomes were evaluated using the classification method. The best APACHE Ⅱ scores were filtered to predict clinical outcomes using the ROC curve and area under ROC.Results:The average age of the patients was 51.39±22.13, length of hospital stay was 52.83 ± 71.22, APACHE-Ⅱ Scores were 15.03±9.93, and the mortality rate was 28.86%. Most cases were collected from SICU (30%), hepatobiliary surgery (15%), respiratory medicine (9%) and Department of Hematology (9%). It was found that Carbapenem resistance was the characteristics of drug susceptibility. The rate of resistance to meropenem was 72.5% and to imipenem was70.8%. There was significant difference in APACHE Ⅱ scores and CRAb infections s between survival group and death group, Whether carbapenems treatment was used could lead to mortality rate differences between CRAb group and CSAb group. Classification method showed a high accuracy rate (81.5% 76.5%) in evaluating clinical outcomes. More than half (52%) of Acinetobacter baumanii blood stream infections were primarily diagnosed as digestive diseases. CRAb infection(P=0.0236), the use of central line catheter (P=0.02), OT(P<0.0001) and CRRT(p<0.0339) were statistically different between digestive diseases group and non-digestive diseases group, so were Invasive procedures, APACHE Ⅱ scores and BMI index between the ICU and general ward.Conclusion:Acinetobacter baumanii blood stream infections are most likely to occur among patients who are critically ill and the mortality rate is 28.86%. SICU. hepatobiliary surgery, respiratory medicine and Department of Hematology are prone to such infections. CRAb and MRAb are the characteristics of drug susceptibility. CRAb infections and APACHE-Ⅱ scores(higher than 19)are the risk factors for death due to Acinetobacter baumanii blood stream infections. Carbapenems treatment may play an active role in reducing mortality rate in Acinetobacter baumanii blood stream infections. Classification method can help to evaluate clinical outcomes in Acinetobacter baumanii blood stream infections. Half of Acinetobacter baumanii blood stream infections areprimarily diagnosed as digestive diseases and most of them use catheters. CRAb blood stream infections are likely to occur in the ICU.2. RNA research based on high-throughput sequencing in Acinetobacter baumanii blood stream infectionsObjective:To investigate the biological difference and drug susceptibility between three strains of Acinetobacter baumani isolated from different culture (blood stream, sputum and nosocomial environment, respectively) by high-throughput sequencing. All the strains were collected form an outbreak of CRAb in 2007 in our hospital and were identified as the same gene type by PFGE (pulsed field gel electrophoresis).Control strain was ATCC19606. Methods:dRNA high-throughput sequencing technology was used. Results:According to GO-standard,Acinetobacter baumanii isolated from blood stream were different in the single-organism, establishment of localizations localization and cellular process. The expression of Gene OXA-95 of Acinetobacter baumanii isolated from blood stream increased more significantly than that of control strains’. Conclusion:Strains of Acinetobacter baumanii isolated from different growth conditions show differences in gene expression patterns. The high expression level of OXA-95 of Acinetobacter baumanii isolated from blood stream may help the CSAb turn into CRAb.