Date of Graduation


Document Type


Degree Name

Doctor of Philosophy in Cell & Molecular Biology (PhD)

Degree Level



Biological Sciences


Julie Stenken

Committee Member

Jeannine Durdik

Second Committee Member

Ingrid Fritsch

Third Committee Member

Jiangchao Zhao


Biofilms, LL-37, solid-phase extraction, THP-1


Healthcare-associated infections (HCAIs) affect 1.7 million hospitalized patients each year, resulting in over 98,000 deaths and anywhere from $28.4 to $45 billion in treatment costs. Furthermore, it has been established that more than 80% of these infections are caused by biofilms While HCAIs can be bacterial, viral, fungal, or parasitic, there are between 12 and 17 species cause 80 to 87% of all HCAIs. Among the most commonly isolated microorganisms are Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). Thus, biofilms are of importance not only due to their prevalence in HCAIs but also due to the increased antibiotic resistance that can be observed in comparison to their planktonic counterparts. Due to the importance of understanding biofilm interaction not only between bacterial species, but also interactions within the host, this research was focused on biofilm interactions using an in vitro co-culture with macrophage-like cells. Due to their prevalence in HCAIs, biofilms of S. aureus, S. epidermidis, and P. aeruginosa were explored. To combat antibiotic resistant microorganisms, research into alternative therapeutic treatments is of importance. One such alternative is cationic antimicrobial peptides. Currently, hCAP-18/LL-37 is the only known human cathelicidin with a broad spectrum anti-microbial response. Its antimicrobial and immunomodulatory properties make it of particular interest in antibiotic resistance research. This dissertation focuses on the development of a method to rapidly detect and quantify LL-37 in an in vitro co-culture setting.

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