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Showcase Medical and Life Sciences

The Sea as a Source of Novel Antiparasitic Compounds

The Sea as a Source of Novel Antiparasitic Compounds

Primary Author: Rachel Relat

Faculty Sponsor: Roberta O’Connor

 

Primary College/Unit: College of Veterinary Medicine

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

 

PRINCIPLE TOPIC

Cryptosporidium, an intracellular parasite that causes severe diarrhea, is now recognized as a leading cause of waterborne disease worldwide, infecting both humans and valuable livestock.  Cryptosporidium infection is particularly devastating in children as it causes life-threatening diarrhea, along with developmental delays including growth stunting and cognitive impairment. Cryptosporidium is an especially important disease of immunocompromised individuals of all ages, leading to chronic, potentially fatal diarrhea. No effective treatment exists for many human or veterinary patients diagnosed with Cryptosporidium.

METHODS

To address this medical imperative, we designed a high throughput screen to test thousands of unique compounds, with the goal of discovering new, potent, anti-Cryptosporidium drugs and drug scaffolds. Our collaborators at the Harbor Branch Oceanographic Institute (HBOI) have amassed a library of over 125 natural compounds, and 6500 highly enriched fractions from extracts of marine organisms. We began screening this library as it contains compounds and fractions produced by sessile oceanic animals which frequently use chemical defenses.  We screened greater than 3,600 partially purified extracts from the HBOI library by infecting cells with Cryptosporidium parvum, allowing replication, and then treating with a specific highly enriched fractions or compounds, and then measuring parasite growth after 48 hours.

RESULTS

We identified 10 extracts derived from sessile marine organisms that effectively inhibit (>80% inhibition) Cryptosporidium without damaging the host cells in which these parasites live. This work will significantly contribute to the goal of discovering effective treatments against Cryptosporidium specifically, and further the search for novel anti-parasitic drugs.

 

Boromycin as a potential anti-toxoplasma and anti-cryptosporidium drug

Boromycin as a potential anti-toxoplasma and anti-cryptosporidium drug

Primary Author: Jaypee Abenoja

Faculty Sponsor: Roberta O’Connor

 

Primary College/Unit: College of Veterinary Medicine

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

Toxoplasma gondii and Cryptosporidium parvum, members of the phylum Apicomplexa, are considered significant pathogens of both humans and animals worldwide. They are obligate intracellular parasites that cause serious conditions like neurological abnormalities, blindness and chronic diarrhea especially to immunocompromised individuals. Unfortunately, aside from significant toxicity on mammalian cells, current therapies against these parasites become ineffective through time because of drug resistance, making the discovery of new therapeutic drugs a priority. Here we described the activity of Boromycin (BM), a lipid-soluble antibiotic produced by Streptomyces antibioticus only known before as a drug for gram positive bacteria, against T. gondii and C. parvum.

BM’s in vitro activity against T. gondii and C. parvum was evaluated using various assays including proliferation inhibition, invasion assay and immunofluorescence to characterize the morphological changes of the parasites after being exposed to BM.

BM potently inhibits intracellular proliferation of T. gondii (EC50=2.13nM) and C. parvum (EC50=6.46nM) into their host cells. Irreversible inhibition on the ability of extracellular T. gondii to invade host cells was also observed after 2 hours of incubation with BM. Furthermore,

immunofluorescence of the parasites using anti-surface antigen glycoprotein-1 (SAG1) antibodies show detectable parasitophorous vacuoles (PV) but with randomly distributed surface antigens and complete loss of morphologically intact parasites within the vacuoles. We also determined after cytotoxicity assays that BM is very selective against parasites at the same time safe to mammalian host cells (Selectivity Index= of 3582.7). These promising results suggest BM as an exciting drug candidate for treating toxoplasmosis and cryptosporidiosis.

Identifying the mechanism of action of Tartrolon E, a broad-spectrum anti-apicomplexan compound

Identifying the mechanism of action of Tartrolon E, a broad-spectrum anti-apicomplexan compound

Primary Author: Gregory Bowden

Faculty Sponsor: Roberta O’Connor

 

Primary College/Unit: College of Veterinary Medicine

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

 

PRINCIPAL TOPIC

The apicomplexan parasite Cryptosporidium is the cause of the severe diarrheal disease, cryptosporidiosis. Cryptosporidiosis is one of the most important diseases of children, immunocompromised individuals, and young ruminant livestock. Currently, there is no treatment for neonatal ruminants, and the only approved treatment for immunocompromised individuals is ineffective; a new treatment is needed.  Recently we identified Tartrolon E (TrtE), a compound from shipworm symbiotic bacteria, to have broad-spectrum anti-apicomplexan parasite activity, including activity against Cryptosporidium. The purpose of this work was to uncover the mechanism of action of TrtE against apicomplexan parasites by examining gene expression during treatment.

METHOD

We studied the mechanism of action of TrtE using the model apicomplexan parasite Toxoplasma gondii. Changes in gene expression during treatment were determined by RNA-sequencing and verified by RT-qPCR. We investigated the potential function of the responsive gene using bioinformatics and immunofluorescence assays. To examine the effect of this gene on parasite susceptibility to TrtE, we deleted the gene using CRISPR/Cas9.

RESULTS

RNA-sequencing data revealed that T. gondii responds to TrtE treatment by upregulating TGME49_272370 (TERG) in a rapid dose-dependent manner. TERG encodes for an unknown protein with multiple predicted transmembrane domains. Immunofluorescence assays located the TERG protein to punctate areas throughout the cytoplasm. The deletion of TERG resulted in a 22% increase in parasite susceptibility to TrtE. In uncovering the mechanism by which TrtE inhibits T. gondii parasites, we may identify a shared pathway critical to apicomplexan parasite survival and advance the search for a new treatment for cryptosporidiosis.

 

Highly Structured Nurse-to-Patient Interactions in an Acute Care Hospital ICU Reduces MRSA Transmission When Limited to Assigned Patient Groups: A Mathematical Model Approach

Highly Structured Nurse-to-Patient Interactions in an Acute Care Hospital ICU Reduces MRSA Transmission When Limited to Assigned Patient Groups: A Mathematical Model Approach

Primary Author: Matthew Mietchen

Faculty Sponsor: Eric Lofgen

 

Primary College/Unit: College of Veterinary Medicine

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

PRINCIPLE TOPIC

The importance of nurse-to-patient contact in hospital settings for reducing healthcare acquired infections (HAIs) has been well documented. However, it is not well understood how specific interaction patterns effect pathogen transmission. Hospital staffing challenges are a reality, and in addition, are difficult and expensive to study. Using disease transmission models is a useful tool to explore the magnitude and the importance of patient care structure in an intensive care unit (ICU).

 

METHODS

A stochastic compartmental model of an 18-bed ICU was used to study how nurse interactions with patients affected the number of methicillin-resistant S. aureus (MRSA) acquisitions. A parameter, gamma, was introduced to represent the proportion of time a nurse spends within an assigned patient sub-group over a one year duration. The model was simulated 10,000 times with gamma being chosen randomly from a uniform distribution within the parameter range. A segmented Poisson regression model was fit to the MRSA acquisitions to detect any relationships or notable change points.

 

RESULTS

A non-linear relationship was observed, resulting in a decrease in acquisitions as the value of gamma increased. The regression model also detected a single change point in MRSA acquisitions at a gamma value of 0.40 (95% confidence interval: 0.37, 0.42). In conclusion, the proportion of time a nurse spends with an assigned group of patients may have large effects on MRSA transmission within an ICU. Highly structured nurse-to-patient contact with limited interactions outside of assigned patient sub-groups, may be important for hospital epidemiology prevention efforts.

 

Differential expression of the rhoptry associated protein -1a in Theileria equi; Implications for host cell invasion

Differential expression of the rhoptry associated protein -1a in Theileria equi; Implications for host cell invasion

Primary Author: Cynthia Onzere

Faculty Sponsor: Carlos Suarez

 

Primary College/Unit: College of Veterinary Medicine

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

 

Principal Topic

Theileria equi (T. equi) is one of the causative agents of equine piroplasmosis, a severe tick-transmitted disease that affects all equid species. Presently, there is no vaccine for the control of the parasite. T. equi is an Apicomplexan organism characterized by the presence of secretory organelles, such as the rhoptries, on the anterior end that are essential for invasion and establishment of the parasite within the host cell. Rhoptry proteins have been shown to be important in the attachment of several apicomplexan parasites to the host cell during invasion. Despite their functional importance, the pattern of expression and potential of rhoptry proteins as vaccine targets in T. equi remain unexplored.

Method

We evaluated the expression of a putative T. equi rhoptry protein known as the rhoptry associated protein-1a (RAP-1a) in the parasite’s invasive stages in horses. RAP-1a was selected because it is widely conserved among the closely related Babesia and Theileria parasites.

Results/implications

Our findings indicate that RAP-1a is expressed in the merozoite stage of development that invades red blood cells (erythrocytes) but it’s not expressed in the sporozoite stage that invades peripheral blood mononuclear cells. This indicates that T. equi RAP-1a could be important for invasion of erythrocytes and could therefore be a marker for pathogenicity because the symptomatic stage of T. equi infection is associated with the intra-erythrocytic stage of the parasite’s development. Future work will be focused on defining the functional relevance of RAP-1a in T. equi and its role in eliciting protective immune responses.

 

Mental Health First Aid: Increasing student pharmacist preparedness to respond through simulation

Mental Health First Aid: Increasing student pharmacist preparedness to respond through simulation

Primary Author: Easton Stoner

Faculty Sponsor: Jennifer Robinson

 

Primary College/Unit: College of Pharmacy and Pharmaceutical Sciences

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

 

Suicidal ideation, depression, and anxiety are common mental health conditions that are present in our communities and classrooms.  Student pharmacists have historically reported feeling under prepared to support those in need during a mental health crisis. Research teams from Washington State University College of Pharmacy and Pharmaceutical Sciences (CPPS) collaborated with The University of Sydney School of Pharmacy to establish a meaningful educational intervention focused on training student pharmacists with the skills and confidence needed to respond to a mental health crisis.

In the of fall 2019, a Mental Health Human Patient Simulation activity was integrated into an already established Mental Health First Aid elective course with an enrollment of 60 doctor of pharmacy students. For the simulation, students were placed into groups of 5-6 and each group participated in three patient simulations: depression with suicidal ideation, depression with no suicidal ideation, and a manic episode. To measure the effectiveness of the course overall, students completed a pre-course and post-course survey to rate confidence in providing mental health first aid.

Results show that students leave the course feeling more confident and rated their preparedness to provide mental health first aid much higher post- course when compared to pre-course ratings. With the rates of suicidal ideation and deaths by suicide being so high, the implications and applicability of this research can be applied to students in all fields in the hope of decreasing the incidence of death by suicide in our communities.

 

Modeling the Impact of Staff to Patient Ratios on MRSA Acquisition in an Intensive Care Unit

Modeling the Impact of Staff to Patient Ratios on MRSA Acquisition in an Intensive Care Unit

Primary Author: Stephanie Sikavitsas Johnson

Faculty Sponsor: Eric Lofgren

 

Primary College/Unit: College of Veterinary Medicine

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

 

Staff-to-Patient ratios in hospitals impact several hospital acquired infections (HAIs). Intuitively, increasing the number of nurses and doctors in an intensive care unit (ICU) should impact rates of HAI transmission by reducing the number of patients per provider, allowing less patient-patient interaction. Designing a study to determine how different staffing ratios would affect HAIs is difficult to in person because of lots of different factors that make each hospital and unit unique. Mathematical modeling can be used instead to simulate how staffing ratios affect methicillin-resistant S. aureus (MRSA) being acquired in a 15-bed ICU.

 

We varied the number of doctors in the ICU from one to three. For each doctor scenario, the nurse -patient ratio was 1:1, 1:2.5, 1:3. And 1:5. We ran each model 1000 times, with each time simulating 1 year in the ICU. The outcome was the mean number of MRSA acquisitions in one year for each of the 12 models. Our baseline model we compared everything to was the single doctor, 1:3 nurse-patient ratio model.

 

Adding more doctors slightly decreased the number of acquisitions, with the steeper decline going from one doctor to two. Going from a 1:3 nursing ratio to 1:1 ratio decreased MRSA acquisition by 64%. Increasing to a 1:5 ratio raised acquisitions 21.5%. These results suggest reduction in provider contact may have an impact on HAI rates. Appropriate staffing should be considered in infection control guidelines, and the cost of staffing be weighed against its impact on infection prevention.

 

Effects of Garlic Extract Released from Calcium Phosphate Scaffolds for Bone Tissue Engineering Applications

Effects of Garlic Extract Released from Calcium Phosphate Scaffolds for Bone Tissue Engineering Applications

Primary Author: Ashley Vu

Faculty Sponsor: Susmita Bose

 

Primary College/Unit: Voiland College of Engineering and Architecture

Category: Medical and Life Sciences

Campus: Pullman

 

Abstract:

 

PRINCIPAL TOPIC

Bone is a constantly remodeling tissue comprised of osteoblast cells which form bone and osteoclast cells which remove old bone through resorption. Garlic is historically known for the prevention and treatment of diseases however knowledge is limited regarding bone health. Animal studies have shown garlic minimizes bone loss through increasing estrogen levels and reducing osteoclast bone resorption. Excessive bone loss can cause porous, brittle bones, commonly known as osteoporosis, which lead to high fracture risks. Utilizing natural alternatives to synthetic medicines can reduce physiological rejection while maintaining relief to ailments and diseases.

 

METHOD

One of the most well-known sulfur compounds extracted from garlic is allicin. The objective is to understand the effects of allicin release on the bone remodeling process. The hypothesis is allicin will show no cytotoxic effects to osteoblast cells and reduce osteoclast resorption. Allicin was extracted from pure garlic powder and loaded onto calcium phosphate scaffolds, mimicking bone tissue composition. Cellular and scaffold surface morphology were imaged post cell culture as well histological staining of an in vivo rat distal femur model.

 

RESULTS/IMPLICATIONS

Results show allicin has no cytotoxic effects on osteoblast morphology and a reduction of osteoclast resorption pit formation. Allicin also shows significantly enhanced collagen formation in vivo, indicating another avenue for improved bone healing. With these results, further knowledge is gained on the ability for garlic to improve bone health in bone tissue engineering applications.