Investigating the Role of Mucin as Frontline Defense of Mucosal Surfaces against Mycobacterium avium Subsp. hominissuis

Table 4

Invasion of epithelial cells by M. avium and E. coli in presence or absence of MUC2.

Bacteria	Invasion (%)
	HEp-2		A549
	None	5% mucin	None	5% mucin
M. avium 104	7.2 ± 0.3	7.0 ± 0.5	8.6 ± 0.4	8.3 ± 0.3
M. avium 3388	6.8 ± 0.4	6.6 ± 0.5	7.9 ± 2	7.6 ± 0.7
E. coli	27 ± 5	16.7 ± 3 ()	20 ± 0.9	11.0 ± 0.4 ()

() compared with the invasion without the presence of mucin. Bacteria were prepared as described in Section 2. Epithelial cells, 90% confluent, were covered with 5% mucin, and bacterial invasion was determined by incubating bacteria with culture cells (with or without mucin) and quantifying the number of intracellular bacteria (percent of invasion). Initial inoculum of 2 × 10⁵ for M. avium 104, 2.4 × 10⁵ for M. avium 3388, and 3.3 × 10⁵ for E. coli was used.