Legionella pneumophilia
- epidemiology
- classification and characteristics
- virulence factors
- transmission and infection
- clinical manifestations
- diagnosis
- treatment
Epidemiology
widespread in environment - soil water, pipes, showers
Classification and Characteristics
- gram negative bacilli
- intracellular pathogen
- 14 serotypes; over 40 Legionella spp.
- thin, faintly staining; easy to miss on a gram stain - acridine orange may be useful
- fastidious; cultured on BCYE agar and require L-cysteine for growth
Virulence Factors
bacteria are motile
Transmission and Infection
Usually point source: water
Clinical Manifesations
causes a widespread spectrum of illness
causes respiratory tract infections
Diagnosis
Treatment
Rountine susceptibility testing not done, as in vitro results do not often correlate with clinical response
First-line is erythromycin
predictibly susceptible to fluoroquinolones, with macrolides as an alternative