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Properties and development of Mycoplasma pneumoniae biofilms in relation to persistence and cytotoxicity.

Feng, Monica
http://orcid.org/0000-0002-0476-7896
http://rave.ohiolink.edu/etdc/view?acc_num=miami1565869297815629

Abstract Details

2019, Doctor of Philosophy, Miami University, Microbiology.
Mycoplasma pneumoniae is a bacterial pathogen that primarily infects the human respiratory tract but is also capable of causing extrapulmonary disease. M. pneumoniae infections are often underdiagnosed because symptoms are typically not severe enough for hospitalization. The diseases that it causes are often recalcitrant and recurrent even after symptoms appear to abate after treatment with antibiotics. Mechanisms of M. pneumoniae pathogenesis have been investigated throughout the years, but a mechanism for persistence in hosts has yet to be proposed. Like other bacterial pathogens, M. pneumoniae has the ability to form biofilms, which are often linked to chronic infections and persistence in hosts, but the relationship in this organism between biofilm formation and persistence has yet to be explored. M. pneumoniae wild-type (WT) and gliding motility mutant strains were used to characterize and determine the effect of motility on biofilm formation in vitro; only the WT strain was used for characterizing M. pneumoniae biofilm formation ex vivo. Scanning electron microscopy was used to visualize both in vitro and ex vivo development of biofilms over time. Confocal laser scanning microscopy allowed visualization of M. pneumoniae biofilm penetration into tissue culture. Increased or decreased motility did not have major effects on the architecture or development of M. pneumoniae biofilms in vitro, distinct from swimming bacteria. Among the motility-associated proteins assessed by immunoblotting, only P200 exhibited any change over the course of M. pneumoniae biofilm formation in vitro in steady-state levels, decreasing over time. There were no detectable changes in localization of key motility-associated proteins in immotile biofilm tower cells as determined by immunofluorescence microscopy. M. pneumoniae biofilm susceptibility to antibiotic inhibition and complement killing was determined in vitro and ex vivo. A modified minimum inhibitory concentration assay was used to determine at what stages an M. pneumoniae biofilm is inhibitable by erythromycin. Complete resistance to erythromycin was acquired by 48 hours after inoculation. Biofilm formation provided as much as twofold protection against complement killing when compared to survival of mechanically dispersed M. pneumoniae cells. This protection against antibiotic treatment and complement killing was recapitulated in an ex vivo model using BEAS-2B human bronchial epithelial cells as the model for tissue culture. Overall, this work tested whether biofilm formation by M. pneumoniae conferred properties of persistence that allows for chronicity in hosts.
Mitchell Balish (Advisor)
Luis Actis (Committee Member)
Annette Bollmann (Committee Member)
Joseph Carlin (Committee Member)
Michael Crowder (Committee Member)
134 p.
Microbiology
Mycoplasma pneumoniae, biofilm, antibiotic resistance, immune evasion

Recommended Citations

Citations

  • Feng, M. (2019). Properties and development of Mycoplasma pneumoniae biofilms in relation to persistence and cytotoxicity. [Doctoral dissertation, Miami University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=miami1565869297815629

    APA Style (7th edition)

  • Feng, Monica. Properties and development of Mycoplasma pneumoniae biofilms in relation to persistence and cytotoxicity. 2019. Miami University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=miami1565869297815629.

    MLA Style (8th edition)

  • Feng, Monica. "Properties and development of Mycoplasma pneumoniae biofilms in relation to persistence and cytotoxicity." Doctoral dissertation, Miami University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1565869297815629

    Chicago Manual of Style (17th edition)

miami1565869297815629
219
© 2019, all rights reserved.
This open access ETD is published by Miami University and OhioLINK.