TABLE 2.

Evaluation of lytA, bguR, and piaB qPCR (alone and in combination) for detection of pneumococci in 250 OP samples^a

Target gene(s)	No. of:
	True positives	False positives	False negatives	True negatives	PPV (%)b	Specificity (%)	Sensitivity (%)
lytA	10	29	1	210	26	88	91
bguR	10	68	1	171	13	72	91
piaB	10	20	1	219	33	92	91
lytA + bguR	10	14	1	225	42	94	91
lytA + piaB	9	11	2	228	45	95	82
bguR + piaB	9	10	2	229	47	96	82
lytA + bguR + piaB	9	8	2	231	53	97	82

^aA positive is defined as any C_T of <40.

^bPositive predictive value (PPV), specificity, and sensitivity were compared to DNA microarray, the study gold standard for pneumococcus-positive samples.