Pathogenic Bacteria in Senile Patients with Lower Respiratory Tract Infection: Their Distribution and Resistance

OBJECTIVE To comprehend the distribution and resistance to antimicrobial agents of the pathogenic bacteria causing lower respiratory tract infection in senile patients. METHODS We analyzed the distribution and resistance of the pathogenic bacteria isolated from 460 sputa samples of aged peoples with lower respiratory tract infection from Jan 2003 to Dec 2005. RESULTS A total of 315 strains of bacteria included 245(77.8%) of Gram-negative bacilli and 70(22.2%) of Gram-positive cocci were isolated.The height of isolation rate of bacteria in the first 5 was as follows in order:Klebsiella pneumoniae Escherichia coli Acinetobacter baumannii Pseudomonas aeruginosa Stenotrophomonas maltophilia.At the same time 136 strains of fungi were isolated.Candida albicans was the most predominant accounted for 60.3%.50.7% Strains of K.pneumoniae and 75.7% strains of E.coli produced ESBLs.The resistance rates of all K.pneumoniae and E.coli to βlactams were above 50%.All isolates of Enterobacteriaceae were sensitive to imipenem or meropenem.The activity of antibacterial agents against P.aeruginosa was coming down. CONCLUSIONS K.pneumoniae and E.coli are the major pathogens in senile patients with lower respiratory tract infection.Increasing of nonfermenters and fungi as an infection should bring great concern.