Analysis of classification and drug resistance of pathogenic bacteria in severe community acquired lower respiratory infection

Objective To investigate the classification and the drug resistance of bacteria in severe community acquired lower respiratory infection. Methods The classification and the drug resistance test of 65 strains of pathogenic bacteria isolated from 80 patients in Respiratory Intensive Care Unit (RICU) from June 2002 to June 2003 were analyzed retrospectively. Results In 65 strains, there were 36 (55.4%) strains of gram-negative bacteria, 24 (36.9%) strains of gram-positive bacteria, and 5 (7.7%) strains of fungi. The main gram-negative bacteria included Streptococcus pneumoniae (13.9%), Staphylococcus epidermidis (12.3%), Staphylococcus aureus (12.3%), and E. faecium (7.7%). There were 8 stains of penicillin resistant strains of Streptococcus pneumorriae (PRSP11.0%). Methicillin resistant strains of Staphylococcus aureus (MRSA) accounted for 11.0%. The main gram-negative bacteria included Pseudomonas aeruginosa (12.3%), Escerichia coli (7.7%), and A. baumanuii (7.7%). Nonfermentative gram-negative bacteria accounted for 20%. Resistant rates of 4 (6.2%) strains of Stenotrophomonas maltophi-lia resistant to commonly used antibiotics were high. There were 4 (6.3%) strains of Candida albicans and 1 strain of Asperigillus fumigatus in fungal infection. Conclusion The 65 strains of pathogenic bacteria include mainly gram-negative bacteria, gram-positive bacteria, and a small amount of fungus infection. Most pathogenic bacteria demonstrate multi-drug resistance. Retrospective analysis of the drug resistance of bacteria is of great significance in the empirical use of antimicrobial agents.