A Novel Method to Assess Antimicrobial Susceptibility in Commensal Oropharyngeal Neisseria-A Pilot Study

Area of Science:

• Microbiology
• Antimicrobial Resistance
• Public Health Surveillance

Background:

• Commensal Neisseria harbor resistance genes transferable to pathogenic Neisseria gonorrhoeae and Neisseria meningitidis.
• Current surveillance methods for oropharyngeal Neisseria antimicrobial susceptibility are laborious, complex, expensive, and use poorly tolerated swabs.
• Development of a non-invasive, efficient method is crucial for monitoring resistance in commensal Neisseria.

Purpose of the Study:

• To evaluate an alternative non-invasive method for isolating oropharyngeal commensal Neisseria.
• To assess the detection of decreased azithromycin susceptibility in commensal Neisseria using selective media.
• To compare the efficacy of oral rinse-and-gargle samples with traditional oropharyngeal swabs.

Main Methods:

• Utilized selective media (LBVT.SNR) with and without azithromycin (2 µg/mL) for culturing Neisseria.
• Collected paired posterior oropharyngeal/tonsillar swabs and oral rinse-and-gargle samples from 10 participants.
• Analyzed Neisseria species diversity, colony counts, and azithromycin susceptibility from both sample types.

Main Results:

• Similar Neisseria species diversity and colony numbers were isolated from both oral rinse and swab samples.
• The proportion of Neisseria colonies with decreased azithromycin susceptibility was comparable between rinse and swab samples.
• Selective media effectively isolated commensal Neisseria and indicated azithromycin resistance.

Conclusions:

• An oral rinse-and-gargle protocol combined with selective culture media is a promising non-invasive surveillance tool.
• This method can monitor antimicrobial susceptibility in oropharyngeal commensal Neisseria.
• Larger studies are needed to validate these encouraging findings for public health surveillance programs.