Richard A. Chole, M.D., Ph.D.

Lindburg Professor and Head
Developmental Biology

Molecular Cell Biology Program
Developmental, Regenerative and Stem Cell Biology Program

  • 314-362-7395

  • 314-747-4388

  • 314-747-1004

  • 8115

  • 1020 McMillan Building



  • bacterial pathogenesis, bone biology, hearing, host-pathogen interactions, inflammation, osteoclasts

  • Role of Pseudomonas aeruginosa biofilms in cholesteatoma

Research Abstract:

Cholesteatomas of the middle ear and mastoid develop as a complication of otitis media. Cholesteatomas are characterized by localized bone resorption and remodeling with keratinocyte proliferation. Infected cholesteatomas are aggressive and cause increased osteolysis. Our laboratory studies bacterial-host interactions (pathogenesis and virulence) in aural cholesteatoma infected with Pseudomonas aeruginosa biofilms. Ps. aeruginosa in an opportunistic bacterial pathogen capable of forming biofilms and is the most common organism isolated from infected cholesteatoma.

We have isolated twelve strains of Ps. aeruginosa from infected cholesteatomas and characterized several pathogenesis factors including, biofilm production, quorum sensing gene expression, alginate gene expression and production, antibiotic resistance and adherence to keratinocytes. We are currently generating a transposon mutant library of one of these clinical isolates in order to identify other virulence factors involved in the pathogenesis of chronic otitis media and cholesteatoma.

Additionally, we have shown that Ps. aeruginosa LPS induces osteoclastogenesis in vitro and in vivo. The role of LPS in bone resorption is complex and involves the coordinated activity of many cell types including osteoclasts, osteoblasts and inflammatory cells. Expression of genes associated with osteoclastogenesis (e.g. RANKL, TNF, and IL-1) is currently being explored.

Selected Publications:

Zhuang L, Jung J, Wang E, Ramos L, Houlihan S, Pashia M, Chole R. Pseudomoas aeruginosa LPS induces osteoclastogenesis through a TLR4 mediated pathway in vivo and in vitro. Laryngoscope 2007 117: 841-847.

Wang E, Jung J, Nason R, Pashia M, Chole R. Characterization of otopathogenic Pseudomonas aeruginosa: a biofilm phenotype. Arch Otolaryngol Head Neck Surg 2005 131: 983-989.

Jung J, Pashia M, Nishimoto S, Faddis B, Chole R. A possible role for nitric oxide in osteoclastogenesis associated with cholesteatoma. Otol Neurotol 2004 25: 661-668.

Jung J, Lin A, Ramos L, Faddis B, Chole R. Nitric oxide synthase I mediates osteoclast activity in vitro and in vivo. J Cell Biochem 2003 89: 613-621.

Chole R, Faddis B. Evidence for microbial biofilms in cholesteatomas. Arch Otolaryngol Head Neck Surg 2002 128: 1129-1133.

Last Updated: 8/3/2011 2:23:44 PM

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