Successful Application of Enzyme-Labeled Oligonucleotide Probe for Rapid and Accurate Cholera Diagnosis in a Clinical Laboratory

Abstract

Two cholera cases were diagnosed using an enzyme-labeled oligonucleotide probe (ELONP) hybridization test for detection of cholera toxin gene (ctx) in a clinical laboratory at Osaka Airport Quarantine Station. The ELONP test with suspicious colonies of Vibrio cholerae O1 grown on TCBS or Vibrio agar plates gave positive result for ctx within 3 hr. We also tried to apply the ELONP test for direct detection of ctx in their stool and their non-selective culture. Specimens from Case #1, which contained 5.9 X 105 CFU/g of V. cholerae Ol in the stool, cultured for 7–8 hr or longer in alkaline peptone water or Marine broth at 37C, became positive for ctx. On the other hand, specimens from Case #2, which contained 8.7 X 108 CFU/ml (of V. cholerae Ol in the stool), gave positive result in this stool itself without any further culture. These data suggest that the ELONP test provides successfully a more rapid and accurate means of identifying “toxigenic” V. cholerae Ol in a clinical laboratory. © 1994, Center For Academic Publications Japan. All rights reserved.