DISCRIMINATION OF STREPTOCOCCUS-PNEUMONIAE FROM OTHER UPPER RESPIRATORY-TRACT STREPTOCOCCI BY ARBITRARILY PRIMED PCR

Objective: In the clinical laboratory, identification of Streptococcus pneumoniae can be confused with other streptococci. Conventional bioc hemical tests such as optochin sensitivity and bile solubility can giv e inconsistent results. this report presents a method to distinguish t rue S. pneumoniae from other upper respiratory tract streptococci when conventional tests fail. Design and Methods: We used arbitrarily prim ed polymerase chain reaction with the single primer M13 universal as a method to distinguish S. pneumoniae from other upper respiratory trac t streptococci. Results: The fingerprint pattern of S. pneumoniae was established by amplifying DNA of S. pneumoniae type strains 1-48 and o f other common upper respiratory tract streptococci at three different DNA concentrations with the single primer M13 universal. From these t ype strains, a common arbitrarily primed-polymerase chain reaction pat tern was identified characterized by two predominant bands of equal in tensity at 800 base pairs and 1100 base pairs. Fingerprint patterns of viridans streptococci were easily distinguishable from those of S. pn eumoniae. Many of the clinical isolates used in this study were equivo cal by conventional tests but were distinguishable by their fingerprin t patterns. Conclusions: Our results indicated that the fingerprint pa ttern of S. pneumoniae is species specific and distinguishes true S. p neumoniae of clinical isolates from other streptococci when convention al biochemical tests are unclear.