A Novel Method to Assess Antimicrobial Susceptibility in Commensal Oropharyngeal <i>Neisseria</i>—A Pilot Study

Commensal <i>Neisseria</i> provide a reservoir of resistance genes that can be transferred to the pathogens <i>Neisseria gonorrhoeae</i> and <i>N. meningitidis</i> in the human oropharynx. Surveillance programs are thus needed to monitor resistance in oropharyngea...

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Bibliographic Details
Main Authors: Jolein Gyonne Elise Laumen, Saïd Abdellati, Christophe Van Dijck, Delphine Martiny, Irith De Baetselier, Sheeba Santhini Manoharan-Basil, Dorien Van den Bossche, Chris Kenyon
Format: Article
Language:English
Published: MDPI AG 2022-01-01
Series:Antibiotics
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Online Access:https://www.mdpi.com/2079-6382/11/1/100
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Summary:Commensal <i>Neisseria</i> provide a reservoir of resistance genes that can be transferred to the pathogens <i>Neisseria gonorrhoeae</i> and <i>N. meningitidis</i> in the human oropharynx. Surveillance programs are thus needed to monitor resistance in oropharyngeal commensal <i>Neisseria,</i> but currently the isolation and antimicrobial susceptibility testing of these commensals is laborious, complex and expensive. In addition, the posterior oropharyngeal/tonsillar swab, which is commonly used to sample oropharyngeal <i>Neisseria</i>, is poorly tolerated by many individuals. We evaluated an alternative non-invasive method to isolate oropharyngeal commensal <i>Neisseria</i> and to detect decreased susceptibility to azithromycin using selective media (LBVT.SNR) with and without azithromycin (2 µg/mL). In this pilot study, we compared paired posterior oropharyngeal/tonsillar swabs and oral rinse-and-gargle samples from 10 participants and demonstrated that a similar <i>Neisseria</i> species diversity and number of colonies were isolated from both sample types. Moreover, the proportion of <i>Neisseria</i> colonies that had a decreased susceptibility to azithromycin was similar in the rinse samples compared to the swabs. This pilot study has produced encouraging data that a simple protocol of oral rinse-and-gargle and culture on plates selective for commensal <i>Neisseria</i> with and without a target antimicrobial can be used as a surveillance tool to monitor antimicrobial susceptibility in commensal oropharyngeal <i>Neisseria.</i> Larger studies are required to validate these findings.
ISSN:2079-6382