Distribution and antibiotic resistance of pathogenic bacteria isolated from 24 141 blood culture samples

OBJECTIVE To investigate the pathogenic bacteria distribution and antibiotic resistance of the isolates from the blood samples collected from Jan.2009 to Dec.2011.METHODS Blood samples were cultivated by BacT/Alert 3D automated system and pathogenic bacteria were identified by VITEK2-Compact system.Antibiotic susceptibility testings were performed according to K-B method,and corresponding results were analyzed with WHONET 5.4 software.RESULTS Totally 1289 strains were isolated from 24 141 blood samples with the positive rate of 5.3 %;among the bacterial strains,the percentages of the gram-negative bacteria,gram-positive bacteria and fungi were 51.7%(667 strains),34.7%(447 strains) and 10.3%(133 strains),respectively.Escherichia coli(15.2%),Klebsiella pneumoniae(7.4%),Acinetobacter baumannii(6.9%) and Pseudomonas aeruginosa(5.5%) were predominant in the gram-negative bacteria,while Staphylococcus epidermidis(7.7%),S.aureus(56.0%),S.hominis(3.5%),and S.haemolyticus(3.2%) were the predominant gram-positive bacteria,and Candida albicans(3.2%) and C.tropicalis(2.3%) were the predominant fungi;the in vitro antibiotic susceptibility testing revealed that amikacin and imipenem also had high susceptibility to E.coli and K.pneumoniae;most antibacterials had low drug susceptibility to P.aeruginosa and A.baumannii;the gram-positive bacteria were highly susceptible to vancomycin,teicoplanin and quinupristin/dalfopristin;voriconazole,amphotericin B and fluconazole were the most powerful antifungal.CONCLUSION The bacterial spectra of the pathogens causing blood stream infections are complex,the drug resistance rates of the species of pathogens are so high that it is necessary to reinforce the monitoring of drug resistance of the pathogens causing blood stream infections and reasonably use antibiotics.