Identification of shiga toxin-producing bacteria by a new immuno-capture toxin gene PCR.
Infections with bacteria producing shiga toxin are responsible for widespread disease and for the death of a large number of people. In the present study, we have developed a rapid method of high specificity for the detection of Shigella dysenteriae by combining immuno-capture of the bacteria and polymerase chain reaction (PCR) amplification of their toxin gene. We compared the sensitivity of our new method, referred to as immuno-capture toxin gene PCR (iTGPCR), with a conventional TGPCR (cTGPCR) method in detecting S. dysenteriae. Approximately 100 colony forming units (CFU) of bacteria in a volume of 400 microl were divided into 20 tubes with 5 CFU (20 microl). One group of 10 tubes was analyzed by iTGPCR and the other by cTGPCR amplification. All were positive in the 10 tubes using iTGPCR but, in contrast, only half were positive in the 10 tubes with the cTGPCR method. This method was used to detect S. dysenteriae type I in sewage samples without the normal tedious preparation methods. These findings suggest that iTGPCR gives enhanced test sensitivity, and allows determination of pathogen serotype, and differentiation of toxin-producing strains from non toxin-producing strains.
Luo
Wen
W
The Key Laboratory of Education Ministry for Cell Biology and Tumor Cell Engineering, Department of Biology, School of Life Sciences, Xiamen University, PR China.
Wang
Sanying
S
Peng
Xuanxian
X
D000907:Antibodies, Bacterial; D017931:DNA Primers; D005798:Genes, Bacterial; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D012722:Sewage / Q000382:microbiology; D022603:Shiga Toxins / Q000096:biosynthesis* / Q000235:genetics; D012762:Shigella dysenteriae / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity
D000907:Antibodies, Bacterial; D017931:DNA Primers; D012722:Sewage; D022603:Shiga Toxins