SliC is a surface-displayed lipoprotein that is required for the anti-lysozyme strategy during Neisseria gonorrhoeae infection
(A, B) N. gonorrhoeae FA1090 wild type and isogenic ΔsliC, ΔsliC/P::sliC, and ΔsliC/P::sliC* were grown for 18 h on solid media, suspended, and added to human cervical epidermal carcinoma (ME180) cells at a MOI of 10:1 for 1, 2, 3, and 4 h. (A) For adherence experiments, cells were washed with PBS and treated with 1% saponin for 15 min. Lysates were collected and aliquots plated on solid media. Results are expressed as the number of CFUs recovered [total number of cell-associated bacteria; (n = 6; mean ±SEMs] (B) For invasion assays, human cells infected with each strain were treated with 100 μg/mL of gentamicin for 2 h. After washing to remove adherent bacteria, the number of invasive gonococci was quantified by lysing the cells with 1% saponin for 15 min. Aliquots of the lysates were plated on solid media. Results are expressed as the number of CFUs recovered after gentamycin treatment (n = 3; mean ±SEMs). The numbers of adherent and internalized bacteria between analyzed strains and wild type N. gonorrhoeae were not statistically significant (ns).