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The atypical bacterial pathogen Mycoplasma pneumoniae is a leading etiological agent of community-acquired pneumonia in humans; infections are often recalcitrant, recurrent and resistant to antibiotic treatment. These characteristics suggest a mechanism that facilitates long-term colonization in hosts. In an in vitro setting, M. pneumoniae forms biofilms that are unusual in that motility plays no more than a very limited role in their formation and development. Given the unusual nature of M. pneumoniae biofilms, open questions remain concerning phenotypes associated with persistence, such as what properties might favour the bacteria while minimizing host damage. M. pneumoniae also produces several cytotoxic molecules including community-acquired respiratory distress syndrome (CARDS) toxin, H2S and H2O2, but how it deploys these agents during growth is unknown. Whereas several biochemical techniques for biofilm disruption were ineffective, sonication was required for disruption of M. pneumoniae biofilms to generate individual cells for comparative studies, suggesting unusual physical properties likely related to the atypical cell envelope. Nonetheless, like for other bacteria, biofilms were less susceptible to antibiotic inhibition and complement killing than dispersed cells, with resistance increasing as the biofilms matured. CARDS toxin levels and enzymatic activities associated with H2S and H2O2 production were highest during early biofilm formation and decreased over time, suggesting attenuation of virulence in connection with chronic infection. Collectively, these findings result in a model of how M. pneumoniae biofilms contribute to both the establishment and propagation of M. pneumoniae infections, and how both biofilm towers and individual cells participate in persistence and chronic disease.

Introduction: Objectives of this study were to determine retail and neighborhood characteristics associated with smokeless tobacco (ST) product promotion, price promotion, and storefront advertising among retailers in Oklahoma.Methods: In this statewide point-of-sale study, we collected data from 1,354 ST retailers. Using store characteristics and census tract information, we estimated summary statistics and adjusted prevalence ratios during 2019–2020.Results: Of ST retailers audited, 11.0% demonstrated ST youth promotion, 43.0% ST price promotions, and 19.6% ST storefront advertising. The adjusted prevalence ratio (aPR) for convenience stores was higher for all three ST strategies: youth promotion (aPR = 3.4, 95% CI 1.9, 6.2), price promotion (aPR = 3.8, 95% CI 2.9, 5.0), and storefront advertising (aPR=16.4, 95% CI 6.7, 40.3) compared to other store types. Metropolitan tobacco retailers had higher aPRs for youth promotion (aPR = 1.7, 95% CI 1.12 2.6) and storefront advertising (aPR = 1.5, 95% CI 1.2, 1.9).Conclusions: Findings of this study suggest there are currently ample opportunities for youth and adults at risk for tobacco initiation to be exposed to ST products in the retail environment. Convenience stores, more likely to be found and utilized in rural areas compared to metropolitan areas, are disproportionately more likely to engage in marketing strategies that could lure youth into trying smokeless tobacco.