Halitosis causing microorganisms producing volatile sulfur compounds

 # Which microorganism is most commonly implicated in the proteolytic breakdown of cellular debris and the production of volatile sulfur compounds (VSCs) contributing to the characteristic halitosis associated with tonsilloliths?

a) Streptococcus pyogenes

b) Porphyromonas gingivalis and other anaerobic bacteria

c) Candida albicans

d) Haemophilus influenzae

The correct answer is B. Porphyromonas gingivalis and other anaerobic bacteria

Anaerobic bacteria, particularly Porphyromonas gingivalis (a Gram-negative anaerobe), along with species like Fusobacterium nucleatum, Prevotella, and Treponema denticola, dominate the microbiota in tonsilloliths. These organisms perform proteolytic degradation of trapped cellular debris, proteins, and leukocytes in the tonsillar crypts, generating hydrogen sulfide (H₂S), methyl mercaptan (CH₃SH), and dimethyl sulfide ((CH₃)₂S)—key volatile sulfur compounds (VSCs) responsible for the foul odor of associated halitosis. This is substantiated by microbiological analyses of tonsilloliths (e.g., via culture and PCR in studies from Clinical and Experimental Otorhinolaryngology and Journal of Breath Research), showing Porphyromonas spp. as the most prevalent anaerobes (up to 48% in cores). The other options are less relevant: Streptococcus pyogenes (a) is an aerobic pathogen linked to tonsillitis but not VSC production; Candida albicans (c) is a fungus involved in oral candidiasis without primary VSC roles; and Haemophilus influenzae (d) is a respiratory facultative anaerobe not typically implicated in oral crypt biofilms or halitosis.