TABLE 2.

Enumeration of infected host cells and associated C. jejuni bacteria (due to adherence and invasion) per cell after 30 min of infection^a

Strain	% of host cells with associated bacteria	No. of internalized bacteria/infected cell (range)	% of infected cells with 1 associated bacterium	% of infected cells with 2 associated bacteria	% of infected cells with 3 to 5 associated bacteria
Undifferentiated 1-day-old INT407 cells
81-176	28.02 ± 3.48	1-3	77	20	3
NCTC11168	13.36 ± 1.04	1-3	81	17	2
RY213	1.34 ± 0.30	≥1	100	0	0
Undifferentiated 1-day-old Caco-2 cells
81-176	19.76 ± 1.87	1-10	50	20	30
NCTC11168	11.56 ± 0.81	1-7	62	20	18
RY213	1.94 ± 0.39	1-3	77	12	10
Differentiated 7-day-old Caco-2 cells
81-176	11.39 ± 0.69	1-5	59	23	18
NCTC11168	16.82 ± 1.38	1-5	56	22	21
RY213	0.92 ± 0.18	≥1	100	0	0

^aAdherence assays were performed using an MOI of ∼10. Caco-2 and INT407 cells were cultured for 1 to 7 days as described in Materials and Methods.