Pathogens distribution in lower respiratory tract infections and analysis of drug resistance

Objective To investigate the pathogens distribution in lower respiratory tract infections and antimicrobial resistance status to provide reference for rational use of antimicrobials in clinic.Methods Bacterial culture of the qualified sputum samples from the patients admitted from May,2009 to May 2011 was performed.The bacteria identification and drug sensitivity tests were done by ATB system.Results Totally 409 strains of bacteria were isolated,the dominant was Gram-negative bacilli(52.8%).Among them,Pseudomonas aeruginosa accounted for 19.1%,Klebsiella pneurnoniae for 10.3% and Escherichia coli for 4.2%.The ESBLs positive rate of Escherichia coli,Klebsiella pneumoniae were 38.1% and 64.7% respectively.106 strains were nonfermenters Gram-negative bacilli,78 strains were Pseudornonas aeruginoa and 13 strains were Acinetobacter.The Gram-positive bacteria were 22 strains.21 strains were staphylococcus and 7 strains were S.aureus and 14 strains were coagulase-negative Staphylococcus with the detection rate of 71.4%.Fungi were 171 strains(41.8%).Most of Gram-negative bacilli were highly sensitive to amikacin and levofloxacin.Conclusion The dominant pathogenic bacteria in lower respiratory tract infection in our area are Gram-negative bacteria.Different bacteria have the different sensitivities to the same antimicrobial agent.The drug resistant rate of Pseudornonas aeruginoa keeps anupward tendency.We should select antibiotics according to the results of drug sensitivity test.