TABLE 4.

Specificity testing of anti-Y and anti-W135 MAbs against N. meningitidis serogroup Y and W135 isolates obtained from Canadian IMD cases in 2003 and 1999 to 2001

Serogroupa	No. of strains	No. identified by MAbs	No. negative with MAbs	Positive reaction ODs			Negative reaction ODs
				Mean	SD	Range	Mean	SD	Range
W135	37	37	0	1.838	0.835	0.939-3.916	0.039	0.020	0.008-0.089
Y	106	105	1b	0.711	0.314	0.212-1.848	0.025	0.009	0.008-0.054

^aSerogroups identified by bacterial agglutination with rabbit antisera (2).

^bThe single isolate was identified as group Y by PCR detection of the serogroup Y-specific siaD gene.