Carranza’s Clinical Periodontology, 12th Ed, Chapter 5

Figure 5-4: A and B) The invasion of epithelial cells by Fusobacterium nucleatum, a gram-negative rod is evident here, OR is it merely an artifact or a passive translocation process? The definitive answer to that is unclear, but it sure does make for a dramatic visual image. If F. nucleatum can indeed invade the epithelial cell, it may facilitate the entry of other pathogenic bacteria. The answer to the invasion question could shed light on whether antibiotic administration is appropriate in treating periodontal disease. Stay tuned!