Detection of Legionella DNA in guinea pig peripheral leukocytes, urine andplasma by the polymerase chain reaction

Legionella DNA has been detected in respiratory tract, serum and urine samp les from patients with pneumonia by the polymerase chain reaction, A guinea pig model was used to assess whether Legionella DNA could also be detected in peripheral leukocytes during active infection, Ten guinea pigs were inf ected intraperitoneally with Legionella pneumophila serogroup 1, and leukoc yte, plasma and urine samples were collected immediately before inoculation and on days 1, 3, 7 and 14 thereafter. All samples were tested for Legione lla DNA by the polymerase chain reaction. Overall, Legionella DNA was detec ted in 55% of leukocyte samples, 28% of urine samples and 21% of plasma sam ples collected after inoculation. The sensitivity of the polymerase chain r eaction on leukocytes was highest for samples collected within 3 days of in oculation. Further studies testing leukocyte samples from human Legionella infection are required to confirm these observations.