Tropical Medicine Commons^™

Proteomic Characterization And Comparison Of The Infective And Adult Life Stage Secretomes From Necator Americanus And Ancylostoma Ceylanicum, Yide Wong, Bruce A Rosa, Luke Becker, Mali Camberis, Graham Legros, Bin Zhan, Maria Elena Bottazzi, Ricardo T Fujiwara, Edita Ritmejeryte, Thewarach Laha, Sujittra Chaiyadet, Piyanan Taweethavonsawat, Paul J Brindley, Bethany K Bracken, Paul R Giacomin, Makedonka Mitreva, Alex Loukas

Faculty, Staff and Students Publications

More than 470 million people globally are infected with the hookworms Ancylostoma ceylanicum and Necator americanus, resulting in an annual loss of 2.1 to 4 million disability-adjusted-life-years. Current infection management approaches are limited by modest drug efficacy, the costs associated with frequent mass drug administration campaigns, and the risk of reinfection and burgeoning drug resistance. Subunit vaccines based on proteins excreted and secreted (ES) by hookworms that reduce worm numbers and associated disease burden are a promising management strategy to overcome these limitations. However, studies on the ES proteomes of hookworms have mainly described proteins from the adult life stage …

Impact Of Antiparasitic Therapy On Cardiovascular Outcomes In Chronic Chagas Disease A Systematic Review And Meta-Analysis, Anis Rassi, Alyssa Grimshaw, Ashwin Sarwal, Ranjit Sah, Sangam Shah, Nelson I Agudelo Higuita, Fabio Mahamed Rassi, Michaele Francesco Corbisiero, Hannah M Kyllo, Jordan Stellern, Samantha Kaplan, Luis A Marcos, Edgar A Ramírez-García, Martin Casapia, Peter Hotez, Maria Elena Bottazzi, Shital Patel, Carlos Franco-Paredes, José Antonio Marin-Neto, Andrés F Henao-Martínez

Faculty, Staff and Students Publications

BACKGROUND: Endemic in more than 20 countries, Chagas disease affects 6.3 million people worldwide, leading to 28,000 new infections and 7700 deaths each year. Previous meta-analyses on antiparasitic treatment need updates to encompass recent studies and to assess key clinically meaningful endpoints. This study aims to evaluate the impact of antitrypanosomal therapy in preventing or reducing disease progression and mortality in chronic Chagas disease.

METHODS: We performed a systematic review and meta-analysis of studies reporting the cardiovascular outcomes of antitrypanosomal therapy in patients with chronic Chagas disease. We searched Ovid Embase, Ovid MEDLINE, Ovid Global Health, Scopus, Web of Science …

Altering The Intracellular Trafficking Of Necator Americanus Gst-1 Antigen Yields Novel Hookworm Mrna Vaccine Candidates, Athos Silva De Oliveira, Leroy Versteeg, Neima Briggs, Rakesh Adhikari, Maria Jose Villar, Jeanna R Redd, Peter Hotez, Maria Elena Bottazzi, Jeroen Pollet

Faculty, Staff and Students Publications

BACKGROUND: The antigen Na-GST-1, expressed by the hookworm Necator americanus, plays crucial biochemical roles in parasite survival. This study explores the development of mRNA vaccine candidates based on Na-GST-1, building on the success of recombinant Na-GST-1 (rNa-GST-1) protein, currently assessed as a subunit vaccine candidate, which has shown promise in preclinical and clinical studies.

METHODOLOGY/FINDINGS: By leveraging the flexible design of RNA vaccines and protein intracellular trafficking signal sequences, we developed three variants of Na-GST-1 as native (cytosolic), secretory, and plasma membrane-anchored (PM) antigens. After one immunization in mice, mRNA vaccines induced an earlier onset of antigen-specific antibodies compared to …

Use Of A Mouse Model For The Isolation Of Borrelia Puertoricensis From Soft Ticks, Edwin Vázquez-Guerrero, Alexander R Kneubehl, Guadalupe C Reyes-Solís, Carlos Machain-Williams, Aparna Krishnavajhala, Paulina Estrada-De Los Santos, Job E Lopez, José Antonio Ibarra

Faculty, Staff and Students Publications

The isolation of tick-borne relapsing fever (TBRF) spirochetes has proven to be a useful tool to understand their distribution in geographic areas where the tick vectors inhabit. However, their isolation and culture are not easy and in general an animal model is needed to achieve this task. Here, argasid ticks were collected from a neighborhood in Ciudad Caucel, and they were identified as Ornithodoros (Alectorobius) puertoricensis. To determine whether these were infected with TBRF bacteria they were fed with healthy mice but only a low burden of spirochetes was observed. An immunosuppressed mouse model was used to feed the ticks …

Targeted Maternal Chagas Disease Screening Among Individuals Born In A Chagas-Endemic Country., Alvaro Proaño, Neil C Shah, Sneider A Gutierrez Guarnizo, Monica Miranda-Schaeubinger, Michael Z Levy, Robert H Gilman, Dustin D Flannery

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Chagas disease is a neglected tropical disease caused by the parasite Trypanosoma cruzi that affects 6 million people worldwide. In the United States, Chagas is estimated to affect 43 000 women of reproductive age. Pregnant persons with Chagas are at risk for congenital transmission to the newborn, which accounts for nearly a quarter of all new cases. In 2022, a US multidisciplinary expert working group4 developed recommendations for increased clinician-directed screening for Chagas. They concluded that women of reproductive age who were born in endemic countries should be tested due to vertical transmission risk. In 2024, Clark and Bern outlined …

Randomized, Observer-Blind, Controlled Phase 1 Study Of The Safety And Immunogenicity Of The Na-Gst-1/Alhydrogel Hookworm Vaccine With Or Without A Cpg Odn Adjuvant In Hookworm-Naïve Adults, David J Diemert, Maria Zumer, Mark Bova, Christina Gibbs-Tewary, Elissa M Malkin, Doreen Campbell, Lara Hoeweler, Guangzhao Li, Maria Elena Bottazzi, Peter J Hotez, Jeffrey M Bethony

Faculty, Staff and Students Publications

BACKGROUND: Recombinant Necator americanus Glutathione-S-Transferase-1 (Na-GST-1) formulated on Alhydrogel (Na-GST-1/Alhydrogel) is being developed to prevent anemia and other complications of N. americanus infection. Antibodies induced by vaccination with recombinant Na-GST-1 are hypothesized to interfere with the blood digestion pathway of adult hookworms in the host. Phase 1 trials have demonstrated the safety of Na-GST-1 formulated on Alhydrogel, but further optimization of the vaccine adjuvant formulation may improve humoral immune responses, thereby increasing the likelihood of vaccine efficacy.

METHODS: A randomized, observer-blind, dose escalation Phase 1 trial was conducted in 24 healthy, hookworm-naïve adults. In each cohort of 12 participants, 4 …

Immunopeptidomic Mhc-I Profiling And Immunogenicity Testing Identifies Tcj2 As A New Chagas Disease Mrna Vaccine Candidate, Leroy Versteeg, Rakesh Adhikari, Gonteria Robinson, Jungsoon Lee, Junfei Wei, Nelufa Islam, Brian Keegan, William K Russell, Cristina Poveda, Maria Jose Villar, Kathryn Jones, Maria Elena Bottazzi, Peter Hotez, Edwin Tijhaar, Jeroen Pollet

Faculty, Staff and Students Publications

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease. Globally 6 to 7 million people are infected by this parasite of which 20-30% will progress to develop Chronic Chagasic Cardiomyopathy (CCC). Despite its high disease burden, no clinically approved vaccine exists for the prevention or treatment of CCC. Developing vaccines that can stimulate T. cruzi-specific CD8+ cytotoxic T cells and eliminate infected cells requires targeting parasitic antigens presented on major histocompatibility complex-I (MHC-I) molecules. We utilized mass spectrometry-based immunopeptidomics to investigate which parasitic peptides are displayed on MHC-I of T. cruzi infected cells. Through duplicate experiments, we identified an …

Therapeutic Effect Of Recombinant Echinococcus Granulosus Antigen B Subunit 2 Protein On Sepsis In A Mouse Model, Ya-Yun Qian, Fei-Fei Huang, Si-Yu Chen, Wei-Xiao Zhang, Yin Wang, Peng-Fei Du, Gen Li, Wen-Bo Ding, Lei Qian, Bin Zhan, Liang Chu, Dong-Hui Jiang, Xiao-Di Yang, Rui Zhou

Faculty, Staff and Students Publications

BACKGROUND: Sepsis is a potentially fatal systemic inflammatory response syndrome (SIRS) that threatens millions of lives worldwide. Echinococcus granulosus antigen B (EgAgB) is a protein released by the larvae of the tapeworm. This protein has been shown to play an important role in modulating host immune response. In this study we expressed EgAgB as soluble recombinant protein in E. coli (rEgAgB) and explored its protective effect on sepsis.

METHODS: The sepsis model was established by cecal ligation and puncture (CLP) procedure in BALB/c mice. The therapeutic effect of rEgAgB on sepsis was performed by interperitoneally injecting 5 µg rEgAgB in …

Complete Genome Sequence Of Borrelia Miyamotoi Strain Mn18-0001, An Am-East-2 Strain Type Isolate Derived From An Ixodes Scapularis Tick (Minnesota), Alexander R Kneubehl, Lynn M Osikowicz, Christina M Parise, Taylor J Van Gundy, Adam J Replogle, Job E Lopez, Rebecca J Eisen, Andrias Hojgaard

Faculty, Staff and Students Publications

We report the genomic sequence of the hard tick relapsing fever spirochete Borrelia miyamotoi strain MN18-0001. B. miyamotoi causes human illness and is geographically widespread in Ixodes spp. (Acari: Ixodidae) ticks. This is a chromosome- and plasmid-resolved genome assembly of an Am-East-2 strain type isolate from the midwestern United States.

Mitochondrial Genome Analysis Across Different Populations Reveals The Intraspecific Variation And Phylogeography Of The Caucasian Soft Tick Relapsing Fever Vector, Ornithodoros (Pavlovskyella) Verrucosus (Ixodida: Argasidae), Serhii Filatov, Alexander R Kneubehl, Aparna Krishnavajhala, Giorgi Melashvili, Ana Tsitsishvili, Küşver Mamedova, Perot Saelao, Adalberto Á Pérez De León, Job E Lopez

Faculty, Staff and Students Publications

Territories in southern parts of Eastern Europe and in the Caucasus are endemic for tick-borne relapsing fever (TBRF), caused by Borrelia caucasica. This spirochete is transmitted exclusively by the bites of Ornithodoros verrucosus; however, the distribution and genetic diversity of the tick vector have not been explored. To address this, we performed a phylogeographic study of O. verrucosus specimens collected across a large geographic distribution. We sequenced and analyzed complete mitochondrial genomes of 54 individual O. verrucosus ticks representing 23 geographically diverse populations from Ukraine, Georgia, and Azerbaijan. We detected 47 unique haplotypes, with every collection site exhibiting distinct polymorphisms. …

A Comparison Of The Diagnostic Capability Of Kato-Katz And Real-Time Pcr For The Assessment Of Treatment Efficacy Of Ivermectin And Albendazole Combination Against T Trichiura Infections, Gabriela Matamoros, Ana Sanchez, Ruben Cimino, Alejandro Krolewiecki, Rojelio Mejia

Faculty, Staff and Students Publications

BACKGROUND: Trichuris trichiura is humans' second most prevalent soil-transmitted helminth (STH) infection after Ascaris lumbricoides, affecting approximately 460 million people worldwide. Despite its sub-optimal sensitivity, especially in low prevalence and infection intensity settings, the modified Kato-Katz (K-K) is still recommended as a diagnostic method by the World Health organization (WHO) guidelines.

METHODOLOGY/PRINCIPAL FINDINGS: Within a randomized clinical trial (RCT) comprising four treatment arms with two different anthelmintics, the present study reports an important secondary research objective to determine the diagnostic agreement between K-K and real-time PCR evaluating treatment efficacy against T. trichiura. The parasitological results were analyzed, including cure rates …

Tick-Borne Diseases And Pregnancy: A Narrative Review Evaluating Pregnancy Complications Caused By Tick-Borne Diseases, Michael W Curtis, Job E Lopez

Faculty, Staff and Students Publications

Ticks are vectors of public health concern because the pathogens they transmit can cause detrimental diseases in humans. Lyme disease, tick-borne relapsing fever, human granulocytic anaplasmosis, Rocky Mountain spotted fever, tick-borne encephalitis, Crimean-Congo hemorrhagic fever, and babesiosis are some of the most common diseases caused by the pathogens transmitted by ticks. The overlap between human activities and tick habitats is growing, contributing to an increase in tick-borne disease cases. Unfortunately, pregnancy as a risk factor for tick-borne diseases is largely ignored. In this narrative review we use case reports, epidemiological studies, and animal studies to evaluate the maternal, pregnancy, and …

Low Prevalence Of Soil Transmitted Helminth Infection In Ugandan Children Hospitalized With Severe Malaria, Drew Capone, Nuzrath Jahan, Ruth Namazzi, Robert Opoka, Chandy John

Paediatrics and Child Health, East Africa

Co-infection by intestinal helminths and Plasmodium spp. may be common in endemic communities. Several studies have identified a relationship between helminth infection, Plasmodium spp. infection and malaria severity. However, the relationship is not well defined, and results are inconclusive. We analyzed stool samples from a cohort of children with severe malaria enrolled in two hospitals in Uganda from 2014-2017 and asymptomatic community children from the same household or neighborhood and enrolled at the same time, all 6 months to 48 months of age. We investigated if intestinal helminth infection modified risk of severe malaria. We extracted nucleic acids from stool …

Phenotypic Diversity Of Type Iii Secretion System Activity In Enteropathogenic Escherichia Coli Clinical Isolates, Carmen A Contreras, Tracy H Hazen, Carmen Guadarrama, Ramón Cervantes-Rivera, Theresa J Ochoa, Pablo Vinuesa, David A Rasko, Jose L Puente

Faculty, Staff and Student Publications

Introduction. Enteropathogenic Escherichia coli (EPEC) strains pose a significant threat as a leading cause of severe childhood diarrhoea in developing nations. EPEC pathogenicity relies on the type III secretion system (T3SS) encoded by the locus of enterocyte effacement (LEE), facilitating the secretion and translocation of bacterial effector proteins.

Gap Statement. While the regulatory roles of PerC (plasmid-encoded regulator) and GrlA (global regulator of LEE-activator) in ler expression and LEE gene activation are well-documented in the EPEC prototype strain E2348/69, understanding the variability in LEE gene expression control mechanisms among clinical EPEC isolates remains an area requiring further investigation.

Aim. This …

Molecular Testing Of Environmental Samples As A Potential Source To Estimate Parasite Infection, Rojelio Mejia, Barton Slatko, Cristina Almazan, Ruben Cimino, Alejandro Krolewiecki, Natalia Montellano Duran, Jacob Edwin Valera Aspetty, Paola Andrea Vargas, Chiara Cássia Oliveira Amorim, Stefan Michael Geiger, Ricardo Toshio Fujiwara, Juan David Ramirez, Luz Marina Llangarí-Arizo, Irene Guadalupe, Liliana E Villanueva-Lizama, Julio Vladimir Cruz-Chan, María Leticia Ojeda, Eva Mereles Aranda, Sandra Ocampos Benedetti, Maritza Dalí Camones Rivera, Eddyson Montalvo Sabino, Carlos Pineda, Eric J Wetzel, Philip J Cooper

Faculty, Staff and Students Publications

We discuss the potential usefulness of molecular testing of soil, dust, and water samples to detect medically important parasites, and where such testing could be used to supplement stool sampling in humans. A wide variety of parasites including protozoa and helminths, many of which are zoonotic, have an important infection reservoir in the environment. In some cases, this environmental period is essential for further parasite development. We describe the progress in implementing methods for the molecular detection of these parasites in soil across eight collaborating centers in Latin America and represent a variety of potential applications in improving our understanding …

Optimization Of Cellular Transduction By The Hiv-Based Pseudovirus Platform With Pan-Coronavirus Spike Proteins, Syamala Rani Thimmiraju, Maria Jose Villar, Jason T Kimata, Ulrich Strych, Maria Elena Bottazzi, Peter J Hotez, Jeroen Pollet

Faculty, Staff and Students Publications

Over the past three years, new SARS-CoV-2 variants have continuously emerged, evolving to a point where an immune response against the original vaccine no longer provided optimal protection against these new strains. During this time, high-throughput neutralization assays based on pseudoviruses have become a valuable tool for assessing the efficacy of new vaccines, screening updated vaccine candidates against emerging variants, and testing the efficacy of new therapeutics such as monoclonal antibodies. Lentiviral vectors derived from HIV-1 are popular for developing pseudo and chimeric viruses due to their ease of use, stability, and long-term transgene expression. However, the HIV-based platform has …

Parasitic Contamination Of Soil In The Southern United States, Christine Crudo Blackburn, Sally Mingshuang Yan, David Mccormick, Lauren Nicholas Herrera, Roumen Borilov Iordanov, Mark Daniel Bailey, Maria Elena Bottazzi, Peter J Hotez, Rojelio Mejia

Faculty, Staff and Students Publications

Parasites are generally associated with lower income countries in tropical and subtropical areas. Still, they are also prevalent in low-income communities in the southern United States. Studies characterizing the epidemiology of parasites in the United States are limited, resulting in little comprehensive understanding of the problem. This study investigated the environmental contamination of parasites in the southern United States by determining each parasite's contamination rate and burden in five low-income communities. A total of 499 soil samples of approximately 50 g were collected from public parks and private residences in Alabama, Louisiana, Mississippi, South Carolina, and Texas. A technique using …

Molecular Detection Of Intestinal Parasites In A Rural Community Of Colombia: A One Health Approach To Explore Potential Environmental-Zoonotic Transmission, Sergio Castañeda, Claudia Patricia Acosta, Luis Reinel Vasquez-A, Luz H Patiño, Rojelio Mejía, Juan David Ramírez

Faculty, Staff and Students Publications

Aims: Protozoan and helminth parasitic infections pose significant public health challenges, especially in developing countries with rural populations marked by suboptimal hygiene practices and socio-economic constraints. The parasites are the etiological agents of these infections and have a notably elevated global prevalence. Therefore, this study focuses on estimating the frequency and transmission dynamics of several parasitic species, including Blastocystis, Giardia, Cryptosporidium spp., Entamoeba histolytica, Ascaris lumbricoides, Trichuris trichiura, Taenia spp. and hookworms, within a rural community in southwest Colombia with a particular emphasis on the One Health framework, considering environmental and zoonotic transmission potentials.

Methods and results: This study involved …

Treatments And The Perspectives Of Developing A Vaccine For Chagas Disease, Priscila Silva Grijó Farani, Kathryn Marie Jones, Cristina Poveda

Faculty, Staff and Students Publications

Chagas disease (CD) treatment and vaccine development are critical due to the significant health burden caused by the disease, especially in Latin America. Current treatments include benznidazole and nifurtimox, which are most effective in the acute phase of the disease but less so in the chronic phase, often with significant side effects. Here, using the available literature, we summarize the progress in vaccine development and new treatments that promise to reduce CD incidence and improve the quality of life for those at risk, particularly in endemic regions. New treatment options, such as posaconazole and fexinidazole, are being explored to improve …

Detection Of Soil-Transmitted Helminths And Schistosoma Spp By Nucleic Acid Amplification Test: Results Of The First 5 Years Of The Only International External Quality Assessment Scheme, Annemiek H J Schutte, Rob Koelewijn, Sitara S R Ajjampur, Bruno Levecke, James S Mccarthy, Rojelio Mejia, Steven A Williams, Jaco J Verweij, Lisette Van Lieshout, Jaap J Van Hellemond

Faculty, Staff and Students Publications

BACKGROUND: Infections with soil-transmitted helminths (STH) and schistosomiasis (SCH) result in a significant global health burden, particularly in rural communities in low and middle-income countries. While microscopy remains the primary diagnostic method for STH and SCH in resource-limited settings, nucleic acid amplification tests (NAATs) are gaining prominence as tools for evaluation of public health control programs in endemic countries, and individual diagnosis in high-income countries. Despite the high sensitivity and specificity of NAATs, previous research has highlighted inter-laboratory variations, both in technical and clinical performance, justifying the need for continuous proficiency testing.

METHODOLOGY: Results from 5 rounds over a 5-year …