Table 1.

S. pneumoniae association with the nasal epithelium in the EHPC model detected by culture, confocal microscopy and LytA PCR

			Sample day				Pneumococcal association
ID	Pneumococcal density	Pre	D2	D6	D9	D27	Surface	Intracellular	Lateral
1	Culture (CFU/ml)	0	373	520	10	2
	Microscopy (counts)	0	+	+	0	+	+	0	0
	LytA PCR	NEG	POS	POS	n/a	POS
2	Culture (CFU/ml)	0	0	0	0	0
	Microscopy (counts)	+	+	0	0	0	++	+	0
	LytA PCR	NEG	NEG	NEG	n/a	NEG
3	Culture (CFU/ml)	0	0	0	0	0
	Microscopy (counts)	0	+	0	0	0	+	0	0
	LytA PCR	NEG	POS	NEG	n/a	NEG
4	Culture (CFU/ml)	0	3	9	0	0
	Microscopy (counts)	0	0	0	+	0	+	0	0
	LytA PCR	NEG	POS	POS	n/a	NEG
5	Culture (CFU/ml)	0	7 × 103	223	22	0
	Microscopy (counts)	0	+	+	+	0	+	+	0
	LytA PCR	n/a	n/a	n/a	n/a	n/a
6	Culture (CFU/ml)	0	1.9 × 104	5.7 × 103	3.7 × 104	11
	Microscopy (counts)	0	++	++++	++	0	+++	++	+
	LytA PCR	NEG	POS	POS	n/a	POS
7	Culture (CFU/ml)	0	822	1.1 × 103	160	0
	Microscopy (counts)	0	+	+++	++	0	++	+	+
	LytA PCR	NEG	POS	POS	n/a	NEG
8	Culture (CFU/ml)	0	0	0	0	0
	Microscopy (counts)	0	0	0	0	0	0	0	0
	LytA PCR	n/a	n/a	n/a	n/a	n/a
9	Culture (CFU/ml)	0	221	695	4	<1
	Microscopy (counts)	n/a	+	+++	+	n/a	+++	+	+
	LytA PCR	NEG	POS	POS	n/a	NEG
10	Culture (CFU/ml)	0	1 × 103	0	0	0
	Microscopy (counts)	n/a	0	+	0	n/a	+	0	0
	LytA PCR	NEG	POS	POS	n/a	POS
11	Culture (CFU/ml)	0	1.8 × 106	1.8 × 106	1.9 × 104	<1
	Microscopy (counts)	n/a	++++	++++	+	n/a	+++	+	+
	LytA PCR	NEG	POS	POS	n/a	NEG
12	Culture (CFU/ml)	0	0	0	0	0
	Microscopy (counts)	n/a	++	0	0	n/a	++	+	+
	LytA PCR	NEG	NEG	NEG	n/a	NEG
13	Culture (CFU/ml)	0	23	2	0	0
	Microscopy (counts)	n/a	+	0	0	n/a	+	0	0
	LytA PCR	POS	POS	POS	n/a	POS

Nasal washes and nasal curette biopsies were collected from carriage positive and carriage negative volunteers over time. Standard methods for measuring bacterial density by culture (CFU) and LytA PCR were compared against counts visualised by confocal microscopy for pneumococcal association with nasal cells over time. The data were derived from 13 volunteers. +(1–10 pneumococci); ++ (11–50 pneumococci); +++(51–100 pneumococci); ++++ (>100 pneumococci); n/a = reading not taken