EHEC O111 O157

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1 (EHEC) (VT) VT RPLA EHEC RPLA 1/4 1/16 EHEC VT , 70 VT Key words: (enterohemorrhagic Escherichia coli;ehec) ) EHEC O157 1) O157 (VT) VT RPLA 2) ELISA 3), 4) PCR 5) VT O157 EHEC 1) ( ) TEL: FAX: kawahara@iph.pref.osaka.jp 6) 8) O26, O111 EHEC O157 EHEC O157 EHEC VT VT EHEC VT VT VT VTEC-RPLA RPLA, 66 Vol. 14 No

2 VT EHEC 39 O157 : H77 29 O26 : H11 6 O111 : HUT 2 O111 : HNM 2 VT E. coli 50 (Table 1) 2002 EHEC 230 EHEC VT 1 VT1 2 VT2 VT 100 ml VT 15 VT 3. VT O Brien 9) VT RPLA TSB, 35 1 TSA, ml BIORUPTOR, 10 EHEC 19 CAYE 2), 10) VT 100 ng/ml RPLA 1 2 Table 1. Specificity of CapiliaVT and RPLA methods performed with clinical isolates. Isolates No. of tested CapiliaVT No. of positive RPLA EHEC (toxin types) VT VT VT Total (Positive rate) (100 ) 39 (100 ) non-ehec Escherichia coli Vibrio cholerae Vibrio parahaemolyticus Citrobacter freundii Aeromonas hydrophila Citrobacter braakii Enterobacter cloacae Escherichia hermanii Klebsiella pneumonia Plesiomonas shigelloides Pseudomonas aeruginosa Salmonella Enteritidis Shigella dysenteriae Shigella sonnei Vibrio vulnificus Total (Positive rate) 50 0 (0 ) 0 (0 ) Vol. 14 No

3 196 VT 1 sodium chloride, methacryloyloxy ethyl phosphorylcholine, 0.05 polyoxyethylene stearyl amine, 0.09 sodium azide 200 mb Tris HCl bu#er ph 7.5 VT EHEC 39 RPLA VT VT 5. VT VT 1ml 50 mg 50 ml 83 CT, CT TSB ml 1ml VT CT CT-SMAC, DHL EHEC 1. VT VT EHEC 39 VT RPLA 100 (Table 1) EHEC E. coli VT 50 EHEC CAYE VT VT RPLA Fig. 1. Sensitivity test of CapiliaVT and RPLA with EHEC isolates. 1 (U) VT1; 8 U, VT2; 4U VT ng/ml, VT ng/ml RPLA ng/ ml EHEC 39 VT 4 U 50 (18/36) 8U 67 (22/33) 16U 100 (37/37) (Fig. 1) VT RPLA VT Table EHEC 4.3, Table 2 Comparison between CapiliaVT and conventional culture method with stools. Culture CapiliaVT Stools No. of tested ( ) Incubated broth No. of tested ( ) 6(2.6) 2 (2.4) 10 (4.3) 11 (13.3) 34 (14.8) 13 (15.7) 180 (78.3) 57 (68.7) Total 230 (100) 83 (100) Concordance rate 186/230 (80.9) 59/83 (71.1) 68 Vol. 14 No

4 VT 197 VT VT B 11) 40 B 1 10 RPLA RPLA ) EHEC VT ELISA 13) EHEC VT O121 : H19 VT2 2 O177 : HNM VT2 1 O157 1 VT O157 VT 2) VT B VT 14) VT VT RPLA ) : ) Vero 71: ) Kehl, K. S., P. Havens, C. E. Behnke, et al Evaluation of the premier EHEC assay for detection of Shiga toxin-producing Escherichia coli. J.Clin. Microbiol. 35: ) ELISA Vero Vero 8: ) PCR 18: ) Fey, P. D., R. S. Wickert, M. E. Rupp, et al Prevalence of non-o157 : H7 shiga toxinproducing Escherichia coli in diarrheal stool samples from Nebraska. Emerg. Infect. Dis. 6: ) Park, C. H., H. J. Kim, D. L. Hixon Importance of testing stool specimens for Shiga toxins. J. Clin. Microbiol. 40: ) : ) O Brien, A. D., G. D. Laveck Immunochemical and cytotoxic activities of Shigella dysenteriae 1(shiga) and shiga-like toxins. Infect. Immun. 35: ) Tsukamoto, T., Y. Kinoshita, S. Taga, et al Value of passive immune hemolysis for detection of heat-labile enterotoxin produced by enterotoxigenic Escherichia coli. J. Clin. Vol. 14 No

5 198 Microbiol. 12: ) Karmali, M. A., M. Petric, C. Lim, et al Sensitive method for detecting low numbers of verotoxin-producing Escherichia coli in mixed cultures by use of colony sweeps and polymyxin extraction of verotoxin. J. Clin. Microbiol. 22: ) (STx) 73: ) University Outbreak of Calicivirus Infection Mistakenly Attributed to Shiga Toxin- Producing Escherichia coli O157 : H7 Virginia, MMWR 50: ) Park, C. H., H. J. Kim, D. L. Hixon, et al Evaluation of the duopath verotoxin test for detection of shiga toxins in cultures of human stools. J. Clin. Microbiol. 41: Evaluation of an Immunochromatographic Test for a Rapid Detection of Vero Toxins Ryuji Kawahara, Kazuko Seto, Masumi Taguchi, Kazuhiro Kobayashi Osaka Prefectural Institute of Public Health Vero Toxins (VT) produced by Enterohemorrhagic Escherichia coli (EHEC) are one of the major virulence factors and bring lethal outcome to some patients due to hemolytic uremic syndrome. CapiliaVT, an immunochromatographic test for the rapid detection of the VT, was evaluated by comparison with the reversed passive latex agglutination (RPLA) kit. All specimens prepared with EHEC isolated 39 strains showed positive and all other pathogenic bacteria 50 strains showed negative for the CapiliaVT kit. The results indicated that the specificity of the kit was completely corresponding with that of RPLA kit. Though, the sensitivity was lower than that of RPLA (between 1/4 to 1/16) when dilution test of samples obtained with EHEC isolates was performed. The sensitivity and specificity of the CapiliaVT kit was lower than that of conventional culture method (EHEC isolation) when 230 stool specimens and 83 further cultured broth were examined. It was shown that the CapiliaVT kit needs further improvement for detection VT in clinical specimens. Considering its rapidity and simplicity, we conclude that the CapiliaVT is the excellent kit to identify EHEC for the isolated strain but remain a problem with sensitivity and specificity. 70 Vol. 14 No