Specific and sensitive two-step polymerase chain reaction assay for the detection of Salmonella species.
A polymerase chain reaction (PCR) assay was applied for the selective amplification of a characteristic sequence within a Salmonella-specific chromosomal fragment. A two-temperature PCR cycle enhanced both the speed and overall sensitivity of the amplification procedure. Twenty-one well-characterized Salmonella strains and a number of non-Salmonella strains were tested. With the exception of the rarely isolated Salmonella arizonae strain, the PCR-based approach enabled the specific identification of Salmonella with a detection limit of 10(3) organisms. In combination with a nested PCR assay, as few as ten organisms were detectable. Specificity was demonstrated as no distinct amplification products were detectable with any of the tested non-Salmonella strains. With a pre-enrichment step using paramagnetic anti-Salmonella beads, an increase in sensitivity was observed in the case of clinical samples while the amplification process was not influenced.
Haedicke
W
W
Institut für Medizinische Mikrobiologie und Hygiene, Universität Regensburg, Germany.
Wolf
H
H
Ehret
W
W
Reischl
U
U
D004269:DNA, Bacterial / Q000032:analysis; D005243:Feces / Q000382:microbiology; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012475:Salmonella / Q000302:isolation & purification*; D012480:Salmonella Infections / Q000175:diagnosis; D012680:Sensitivity and Specificity; D013997:Time Factors
D004269:DNA, Bacterial