Rapid detection of Haemophilus influenzae by hel gene polymerase chain reaction.
OBJECTIVE
To evaluate the efficiency of hel gene polymerase chain reaction (PCR) to detect Haemophilus influenzae in various clinical/non-clinical samples.


RESULTS
Seventy-four clinical samples (cerebrospinal fluid, blood, sputum, throat and nasal swabs) and throat swabs of 17 asymptomatic carriers were collected. Primers were used to amplify the hel gene of H. influenzae encoding P4 outer membrane protein directly from the processed samples. The samples were also examined by conventional culture methods and the results were compared with those of PCR. The culture methods showed positive results in 60 (65.9%) of 91 samples in contrast to 62 (68.12%) samples tested positive by PCR. None of the culture-positive samples were PCR-negative while two of the culture-negative samples were PCR-positive. The specificity of the products was confirmed by Southern hybridization and failure of various other organisms to amplify the hel gene product. The sensitivity of the PCR assay was found to be 50 pg of DNA.


CONCLUSIONS
These findings suggest that the hel gene PCR is a rapid, sensitive and a specific new method for direct identification of H. influenzae.


CONCLUSIONS
Thus, this PCR test can improve the detection rate of H. influenzae in suspected clinical samples as compared with that of conventional culture methods.
Yadav
M C
MC
Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Chakraborti
A
A
Ray
P
P
Sapru
S
S
Majumdar
S
S
Narang
A
A
D000293:Adolescent; D000328:Adult; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D006192:Haemophilus Infections / Q000382:microbiology; D006193:Haemophilus influenzae / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors
D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial