Quantitative Bacteriology of the Parotid Salivary Gland in Health and Sjögren's Syndrome

Why Should We Consider Potential Roles of Oral Bacteria in the Pathogenesis of Sjögren Syndrome?

“…In the culture of 3 consecutive 0.5 ml samples, the mean viable concentration of bacteria rapidly fell in the healthy group from 6.9×10 3 to 0.3×10 3 colony forming units (cfu)/ml, suggesting the cleansing effect of salivary secretion. Although the third sample could be collected from only 5 of 14 patients with SS due to the reduced salivary flow rate, a much higher number of bacteria (2.6×10 3 cfu/ml) was detected in the samples ( 54 ). Reduction in salivary secretion indicates loss of the antimicrobial activity of the saliva.…”

“…Lewis et al ( 54 ) reported the isolation of bacteria from stimulated parotid saliva collected from healthy individuals and patients with SS using modified Carlsson-Crittenden cups. In the culture of 3 consecutive 0.5 ml samples, the mean viable concentration of bacteria rapidly fell in the healthy group from 6.9×10 3 to 0.3×10 3 colony forming units (cfu)/ml, suggesting the cleansing effect of salivary secretion.…”

“…Among the Ro60 orthologs, the top 3 species ( Corynebacterium amycolatum , Propionibacterium propionicum , and Actinomyces massiliensis ) closest to human Ro60 have remarkably high sequence homology with Ro60 both at the early B-cell epitope and a major T-cell epitope, 85% and 70%, respectively. P. propionicum and A. massiliensis , as oral commensals, are isolated from parotid saliva ( 54 ). P. propionicum is also a member of ocular commensals ( 79 ).…”