O Serogroup-Specific Touchdown-Multiplex Polymerase Chain Reaction for Detection and Identification of Vibrio cholerae O1, O139, and Non-O1/Non-O139

Table 4

Amplification specificity of TMPCR and 16S rDNA-specific PCR.

Organism	Strains tested; ()	Specificity (%)
		TMPCR^a	16S rDNA PCR^b
V. cholerae O1	21	100	100
V. cholerae O139	16	100	100
V. cholerae NAG I^c	16	100	100
V. cholerae NAG II^d	16	100	100
Other vibrios	8	0	100
Gram-negative bacteria	16	0	100
Gram-positive bacteria	7	0	100

The specificity (%) = strains showing a positive amplification of expected amplicon sizes by TMPCR as having no cross-hybridization with negative controls/a total of strains tested, multiplied by 100.
^bAs for 16S rDNA-specific PCR, no cross-hybridization occurred in reactions containing nuclease-free water or no DNA.
^cNAG I non-O1/non-O139 growing in semisolid agar in the presence of sucrose and mannose but not arabinose.
^dNAG II non-O1/non-O139 growing in semisolid agar only supplemented with sucrose.