Persistence and spread of the orally-implanted bacterium Streptococcus sanguis between persons

Area of Science:

• Oral microbiology
• Infectious diseases

Background:

• Streptococcus sanguis is a common oral bacterium.
• Understanding the persistence and transmission of antibiotic-resistant bacteria is crucial for public health.

Purpose of the Study:

• To investigate the long-term persistence of transformant strains of streptomycin-resistant Streptococcus sanguis.
• To determine the natural transmission of these resistant bacteria within a household setting.

Main Methods:

• Oral implantation of streptomycin-resistant Streptococcus sanguis in human subjects.
• Long-term follow-up examinations including saliva and mucosal sampling.
• Quantification of resistant bacteria using colony-forming units (c.f.u.) and percentage of total Streptococcus sanguis.

Main Results:

• Resistant Streptococcus sanguis persisted for up to 2.5 years in 6 out of 11 subjects.
• Natural transmission to spouses occurred in 5 of the 6 infected subjects.
• Significant levels of resistant bacteria were detected in both infected subjects and their spouses.

Conclusions:

• Transformant strains of streptomycin-resistant Streptococcus sanguis can persist in the oral cavity for extended periods.
• Natural transmission of these resistant bacteria between intimate partners is possible.
• This highlights the potential for long-term carriage and spread of antibiotic resistance within close contacts.