Verification of an Edwardsiella ictaluri-specific diagnostic PCR.
OBJECTIVE
To verify the specificity of a PCR assay for the identification and diagnosis of Edwardsiella ictaluri.


RESULTS
An Edwardsiella ictaluri-specific PCR assay was developed utilizing two features of the ribosomal DNA gene clusters. The first feature is the presence of two ribosomal gene clusters located in tandem to one another (the inter-ribosomal spacer, IRS). This characteristic is present in the Edwardsiella genus but absent in the other sequenced members of the Enterobacteriaceae. The second feature is the presence of an intervening sequence (IVS) in the 23S rRNA gene of Edw. ictaluri. To verify the specificity of this assay, we tested genomic DNA from a variety of bacterial species. The IVS/IRS PCR assay results in an c. 2000-bp product from all Edw. ictaluri isolates tested, but not from any other species including Edwardsiella tarda.


CONCLUSIONS
The IVS/IRS PCR assay is highly specific for Edw. ictaluri and useful as a tool for identifying this pathogen.


CONCLUSIONS
This research verifies the specificity of PCR-based assay for Edw. Ictaluri, and we describe this assay as a highly versatile diagnostic tool for its identification.
Williams
M L
ML
College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.
Lawrence
M L
ML
D000818:Animals; D002397:Catfishes / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics*; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D020610:Edwardsiella ictaluri / Q000235:genetics* / Q000302:isolation & purification; D020609:Edwardsiella tarda / Q000235:genetics; D005393:Fish Diseases / Q000175:diagnosis / Q000235:genetics / Q000382:microbiology; D005810:Multigene Family / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012329:RNA, Bacterial / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D012680:Sensitivity and Specificity; D013045:Species Specificity
D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S