Value of the polymerase chain reaction assay in noninvasive respiratory samples for diagnosis of community-acquired pneumonia.
We studied the causes of community-acquired pneumonia (CAP) in 184 patients. Microbiologic evaluation included sputum examination, blood culture, assessment of acute and convalescent antibody titers for Legionella pneumophila, Mycoplasma pneumoniae, Chlamydia pneumoniae, Coxiella psitacci, Coxiella burnetii and respiratory viruses, polymerase chain reaction (PCR) assays for M. pneumoniae and C. pneumoniae in throat swab, and PCR assay based on the amplification of pneumolysin gene fragment in sera. The causative pathogen was identified in 78 patients (Streptococcus pneumoniae, 44; M. pneumoniae, 26; C. pneumoniae, 1; others, 7). S. pneumoniae was detected in serum by the PCR assay in 41 patients, five of whom also had a positive blood culture. PCR assay was negative in two patients with positive blood culture for S. pneumoniae. C. pneumoniae was detected by PCR in nine patients, but only one showed seroconversion. M. pneumoniae was detected by PCR in only three patients (two without seroconversion). The diagnosis of pneumonia caused by S. pneumoniae was five times greater using PCR in serum than with blood culture. Detection of C. pneumoniae by PCR without fulfilling criteria for acute infection may be considered a prior infection. The PCR assay for the diagnosis of M. pneumoniae has a lower sensitivity than serologic methods.
Menéndez
R
R
Services of Pneumology and Clinical Microbiology, Hospital Universitario La Fe, Valencia, Spain.
Córdoba
J
J
de La Cuadra
P
P
Cremades
M J
MJ
López-Hontagas
J L
JL
Salavert
M
M
Gobernado
M
M
D000293:Adolescent; D000368:Aged; D001426:Bacterial Proteins; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000382:microbiology*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009177:Mycoplasma pneumoniae / Q000302:isolation & purification; D010614:Pharynx / Q000382:microbiology; D011014:Pneumonia / Q000175:diagnosis* / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000592:standards*; D011446:Prospective Studies; D013183:Sputum / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification; D013301:Streptolysins / Q000235:genetics
D001426:Bacterial Proteins; D013301:Streptolysins; C032290:plY protein, Streptococcus pneumoniae