Change of composition of pathogenic bacteria causing lower respiratory tract infections and analysis of drug resistance during 2000-2010

OBJECTIVE To investigate the change of distribution and antibiotic resistance rates of pathogenic bacteria causing infections isolated from lower respiratory tract during 2000-2010.METHODS All the clinical isolates were analyzed retrospectively from children of lower respiratory tract from 2001 to 2010.Distribution and resistance of pathogens were analyzed in 2802 culture positive samples in recent 10 years.The results were respectively divided into three groups,2000-2003,2004-2006,2007-2010 group.RESULTS A total of 2820 clinical isolates were collected,including 2207(78.26%) strains of Gram-negative bacilli and 439(15.57%) strains of Gram-positive cocci.The most common Gram-negative pathogens were,Klebsiella pneumoniae,Escherichia coli,Pseudomonas aeruginosa,Stenotrphomonas maltophilia,Enterobacter cloacae;the most common Gram-positive cocci were Staphylococcus aureus and Streptococcus pneumonia.The proportion of Gram-negative microorganism increased gradually.Most strains of Gram-negative bacilli were susceptible to meropenem,cefoperazone,sulbactam/amikacin,but highly resistant to penicillins and cephalosporins.CONCLUSION The most common pathogens causing lower respiratory tract infections are Gram-negative bacilli from 2000 to 2010.The bacteria resistant rates to common antibiotics are gradually increased.