Detection of Streptococcus pneumoniae in sputum samples by PCR

Abstract

A method for the detection of Streptococcus pneumoniae in sputum samples by PCR has been developed. The assay employs oligonucleotide primers specific for a portion of the autolysin gene lytA of S. pneumoniae. Other closely related streptococci, Haemophilus influenzae, and Moraxella catarrhalis do not give a positive result in the assay. The assay was capable of detecting between 10 and 100 CFU of S. pneumoniae in distilled water and 1.4 x 104 CFU/ml in simulated sputum samples. Sputum samples from 33 patients with acute pneumonia were collected and subjected to culture, PCR, and C-polysaccharide antigen detection by enzyme-linked immunosorbent assay (ELISA). A significant isolate of S. pneumoniae was isolated from 14 patients, of which 13 were positive by PCR and C-polysaccharide antigen ELISA. No positive results were obtained for the 19 patients in whom other pathogens or upper respiratory tract floras only were isolated. The sensitivity of the autolysin PCR is 92.8%, the specificity is 100%, the predictive value of a positive result is 100%, and the predictive value of a negative result is 95%. This suggests that autolysin PCR is suitable for the detection of S. pneumoniae in clinical samples.

Horizontal gene transfer and the evolution of resistance and virulence determinants in Streptococcus

“…2). Isolates found to possess these direct repeats were PCR primers used to amplify lytA and thereby prove the presence of pneumococci (Gillespie et al 1994) were also almost exclusively serotype 3, although only about 50% of the 40 serotype 3 isolates examined possessed the insert. found to amplify lytA from the isolate of Strep.…”

A Modified PCR‐Based Method for Rapid Non‐Radioactive Detection of Clinically Important Pathogens

“…At present, PCR is used in the detection of different infectious agents, e.g. S. aureus (1,11), S. pneumoniae (6,19), Mycobacterium (7,18), Chlamydia trachomatis (3), Pseudomonas (2, 10), etc. Many published protocols utilize different modifications of a direct PCR ("nested," "multiplex," and the like) and can detect 103-104 bacteria during 4-5 hr.…”

Direct detection of Streptococcus mutans in human dental plaque by polymerase chain reaction

“…Extraction of chromosomal DNA from the other gram-positive bacteria and the clinical isolates of S. mutans was carried out by the chloroform method of Gillespie et al (6). Briefly, the cells were heat-inactivated and vortex-mixed with chloroform and TE, pH 8.0.…”

“…In order to obviate such limitations, polymerase chain reaction seems to be useful. Although polymerase chain reaction has generally been used to detect and identify a wide range of pathogens (4,6,8,20), the polymerase chain reaction method to detect S. mutans specifically has not been available yet. The detection level of S. mutans by using selective mitissalivarius agar supplemented with bacitracin is good as well as the polymerase chain reaction method; however, it would take longer than the polymerase chain reaction method.…”