Pathology Commons^™

The Prospect Of Nanoparticle Systems For Modulating Immune Cell Polarization During Central Nervous System Infection, Lee E. Korshoj, Wen Shi, Bin Duan, Tammy Kielian

Journal Articles: Pathology and Microbiology

The blood-brain barrier (BBB) selectively restricts the entry of molecules from peripheral circulation into the central nervous system (CNS) parenchyma. Despite this protective barrier, bacteria and other pathogens can still invade the CNS, often as a consequence of immune deficiencies or complications following neurosurgical procedures. These infections are difficult to treat since many bacteria, such as Staphylococcus aureus, encode a repertoire of virulence factors, can acquire antibiotic resistance, and form biofilm. Additionally, pathogens can leverage virulence factor production to polarize host immune cells towards an anti-inflammatory phenotype, leading to chronic infection. The difficulty of pathogen clearance is magnified by …

Crosstalk Between Staphylococcus Aureus And Innate Immunity: Focus On Immunometabolism, Christopher M. Horn, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a leading cause of bacterial infections globally in both healthcare and community settings. The success of this bacterium is the product of an expansive repertoire of virulence factors in combination with acquired antibiotic resistance and propensity for biofilm formation. S. aureus leverages these factors to adapt to and subvert the host immune response. With the burgeoning field of immunometabolism, it has become clear that the metabolic program of leukocytes dictates their inflammatory status and overall effectiveness in clearing an infection. The metabolic flexibility of S. aureus offers an inherent means by which the pathogen could manipulate the …

Immunopathogenesis Of Craniotomy Infection And Niche-Specific Immune Responses To Biofilm, Sharon D.B. De Morais, Gunjan Kak, Joseph P. Menousek, Tammy Kielian

Journal Articles: Pathology and Microbiology

Bacterial infections in the central nervous system (CNS) can be life threatening and often impair neurological function. Biofilm infection is a complication following craniotomy, a neurosurgical procedure that involves the removal and replacement of a skull fragment (bone flap) to access the brain for surgical intervention. The incidence of infection following craniotomy ranges from 1% to 3% with approximately half caused by Staphylococcus aureus (S. aureus). These infections present a significant therapeutic challenge due to the antibiotic tolerance of biofilm and unique immune properties of the CNS. Previous studies have revealed a critical role for innate immune responses …

Staphylococcus Aureus Atp Synthase Promotes Biofilm Persistence By Influencing Innate Immunity, Megan E. Bosch, Blake P. Bertrand, Cortney E. Heim, Abdulelah A. Alqarzaee, Sujata S. Chaudhari, Amy L. Aldrich, Paul D. Fey, Vinai C. Thomas, Tammy Kielian

Journal Articles: Pathology and Microbiology

No abstract provided.

Tlr2 And Caspase-1 Signaling Are Critical For Bacterial Containment But Not Clearance During Craniotomy-Associated Biofilm Infection, Amy L. Aldrich, Cortney E. Heim, Wen Shi, Rachel W. Fallet, Bin Duan, Tammy Kielian

Journal Articles: Pathology and Microbiology

BACKGROUND: A craniotomy is required to access the brain for tumor resection or epilepsy treatment, and despite precautionary measures, infectious complications occur at a frequency of 1-3%. Approximately half of craniotomy infections are caused by Staphylococcus aureus (S. aureus) that forms a biofilm on the bone flap, which is recalcitrant to antibiotics. Our prior work in a mouse model of S. aureus craniotomy infection revealed a critical role for myeloid differentiation factor 88 (MyD88) in bacterial containment and pro-inflammatory mediator production. Since numerous receptors utilize MyD88 as a signaling adaptor, the current study examined the importance of Toll-like receptor 2 …

Il-10 Plays An Important Role In The Control Of Inflammation But Not In The Bacterial Burden In S. Epidermidis Cns Catheter Infection., Yenis M. Gutierrez-Murgas, Gwenn Skar, Danielle Ramirez, Matthew Beaver, Jessica N. Snowden

Journal Articles: Pathology and Microbiology

BACKGROUND: Shunt infection is a frequent and serious complication in the surgical treatment in hydrocephalus. Previous studies have shown an attenuated immune response to these biofilm-mediated infections. We proposed that IL-10 reduces the inflammatory response to Staphylococcus epidermidis (S. epidermidis) CNS catheter infection.

METHODS: In this study, a murine model of catheter-associated S. epidermidis biofilm infection in the CNS was generated based on a well-established similar model for S. aureus. The catheters were pre-coated with a clinically derived biofilm-forming strain of S. epidermidis (strain 1457) which were then stereotactically implanted into the lateral left ventricle of 8-week-old C57BL/6 and IL-10 …

Hiding In Plain Sight: Interplay Between Staphylococcal Biofilms And Host Immunity., Tyler D. Scherr, Cortney E. Heim, John M. Morrison, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus and Staphylococcus epidermidis are notable for their propensity to form biofilms on implanted medical devices. Staphylococcal biofilm infections are typified by their recalcitrance to antibiotics and ability to circumvent host immune-mediated clearance, resulting in the establishment of chronic infections that are often recurrent in nature. Indeed, the immunomodulatory lifestyle of biofilms seemingly shapes the host immune response to ensure biofilm engraftment and persistence in an immune competent host. Here, we provide a brief review of the mechanisms whereby S. aureus and S. epidermidis biofilms manipulate host-pathogen interactions and discuss the concept of microenvironment maintenance in infectious outcomes, as …