Bacterial agents of lower respiratory tract infections (LRTIs), beta-lactamase production, and resistance to antibiotics in elderly people. DEDALO Study Group

Int J Antimicrob Agents. 2000 Dec;16(4):467-71. doi: 10.1016/s0924-8579(00)00277-6.


This study determined the etiology of lower respiratory tract infections in the elderly and assessed whether the growth of beta-lactamase producing bacteria is particularly favoured in these patients. Between December 1998 and May 1999, 187 patients with community-acquired pneumonia (CAP), and 887 patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) were enrolled. The mean age was 74 years (range of 65-94 year). Sputum and bronchial aspirate for microbiological investigation were obtained. Besides organisms commonly involved in bacterial infections of the lower respiratory tract (i.e. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis), Enterobacteriaceae and Pseudomonas spp. were also found. A high percentage of these bacteria were beta-lactamase producers. These data along with the clinical presentation, severity of infection, and epidemiological knowledge, might represent a guide for the choice of empiric antimicrobial treatment.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology
  • Citrobacter / drug effects
  • Citrobacter / enzymology*
  • Community-Acquired Infections / epidemiology
  • Community-Acquired Infections / microbiology*
  • Drug Resistance, Microbial
  • Enterobacter / drug effects
  • Enterobacter / enzymology*
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology
  • Female
  • Humans
  • Male
  • Microbial Sensitivity Tests
  • Respiratory Tract Infections / epidemiology
  • Respiratory Tract Infections / microbiology*
  • beta-Lactamases / metabolism*


  • Anti-Bacterial Agents
  • beta-Lactamases