Detection of Haemophilus influenzae in respiratory secretions from pneumonia patients by quantitative real-time polymerase chain reaction.
A quantitative real-time polymerase chain reaction (PCR) based on the omp P6 gene was developed to detect Haemophilus influenzae. Its specificity was determined by analysis of 29 strains of 11 different Haemophilus spp. and was compared with PCR assays having other target genes: rnpB, 16S rRNA, and bexA. The method was evaluated on nasopharyngeal aspirates from 166 adult patients with community-acquired pneumonia. When 10(4) DNA copies/mL was used as cutoff limit for the method, P6 PCR had a sensitivity of 97.5% and a specificity of 96.0% compared with the culture. Of 20 culture-negative but P6 PCR-positive cases, 18 were confirmed by fucK PCR as H. influenzae. Five (5.9%) of 84 nasopharyngeal aspirates from adult controls tested PCR positive. We conclude that the P6 real-time PCR is both sensitive and specific for identification of H. influenzae in respiratory secretions. Quantification facilitates discrimination between disease-causing H. influenzae strains and commensal colonization.
Abdeldaim
Guma M K
GM
Department of Clinical Microbiology, Uppsala University Hospital, S-751 85 Uppsala, Sweden.
Strålin
Kristoffer
K
Kirsebom
Leif A
LA
Olcén
Per
P
Blomberg
Jonas
J
Herrmann
Björn
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D012634:Bodily Secretions / Q000382:microbiology; D017714:Community-Acquired Infections / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D006192:Haemophilus Infections / Q000175:diagnosis*; D006193:Haemophilus influenzae / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D009305:Nasopharynx / Q000382:microbiology; D018410:Pneumonia, Bacterial / Q000175:diagnosis*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA
D001425:Bacterial Outer Membrane Proteins; D017931:DNA Primers; D004269:DNA, Bacterial