Analysis of bacterial resistance during 2013

Objective To investigate the distribution and antimicrobial resistance of clinical bacterial isolates in the Second Affiliated Hospital of Nanchang University. Methods Antimicrobial susceptibility testing was carried out using Kirby-Bauer method or automated systems. Results were determined according to the breakpoints of CLSI2013. All data were analyzed by WHONET5. 5 software. Results A total of 3,996 nonduplicate clinical isolates were collected during 2013,including gram negative bacteria( 2623,65. 6%) and gram positive bacteria( 1373,34. 4%). The main sources of the specimens were sputum( 23. 2%),followed by blood( 21. 6%) and urine( 17.8%). The top five bacterial species were Escherichia coli,Klebsiella pneumoniae,Staphylococcus aureus,Pseudomonas aeruginosa and Acinetobacter baumannii,accounting for 20. 9%,10. 1%,9. 4%,8. 7% and 7. 4%,respectively. The prevalence of MRSA in S. aureus and MRCNS in Coagulase-negative Staphylococcus was 21. 3%and 82. 0%,respectively. No staphylococcal strain was found resistant to vancomycin and tigecycline. The prevalence of PRSP was 16. 4%. The resistance rates of beta-hemolytic Streptococcus to eythromycin,cindamycin and tetracycline were higher. The resistance rates of E. faecium strains to most tested drugs were much higher than those of E. faecalis. Vancomycin resistance was found in 2 E. faecalis strains. The prevalence of ESBLs was60. 2% in E. coli and 27. 2% in Klebsiella spp.( K. pneumoniae and K. oxytoca). ESBLs-producing strains were more resistant to most antibiotics than non-ESBLs-producing strains. Enterobacteriaceae strains were very sensitive to carbapenems,and the percentages of Enterobacteriaceae strains resistant to ertapenem and imipenem were less than 10%. Imipenem resistance was found in 8. 7% of P. aeruginosa isolates. More than 50. 0% of the A. baumannii strains were resistant to all the drug tested except levofloxacin,to which only 34. 6% were resistant. The detection rate of multi-drug resistant A. baumannii was 74. 9%. Conclusion The majority of clinical isolates in our hospital during 2013 is still gram negative bacilli. Bacterial resistance remains an important problem in clinical practice. Especially the resistance rate of Klebsiella pneumoniae to carbapenems is increasing rapidly,which should be paid high attention.