The distribution and resistance of pathogenic bacteria in senile patients with lower respiratory tract infection

Objective:To comprehend the distribution and resistance to antimicrobial agents of pathogenic bacteria causing lower respiratory tract infection in senile patients of our hospital.Methods:The bacterial culturing and the tests on the antibiotic from the deep phlegm of the senile patients with lower respiratory infection from January 2005 to January 2006 were retrospectively analyzed.Results:Totally 472 phlegm samples were tested and 376 of them had bacteria with the positive rate of 79.7%.396 strains of bacteria were isolated from them.The strains of Gram-negative bacilli were 270(68.2%);there were 71 strains of Gram-positive cocci(17.9%)and there were 55 strains of fungi(13.9%).P.aeruginosa occupied the first place.14.7% strains of K.pneumoniae and 20.8% strains of E.coli produced ESBLs.Drug test showed that all isolates of Enterobacteriaceae were sensitive to imipenem.The activity of antibacterial agents against P.aeruginosa was coming down and 20.0% strains of imipenem were resistant to drug.Staphyloccus were all sensitive to vancomycin.Conclusion:The Gram-negative bacilli are the major pathogens in senile patients with lower respiratory tract infection and its drug-resistance is heavier.It is necessary for clinic microbiology to enhance the monitoring of pathogen and drug-resistance so as to give suggestions to rational use of antibiotics.