Dr. Sarah Hamer Protects Human, Animal Lives Through Kissing Bugs Project

Stumbling across an unidentified large black bug in your house may make you feel panicked or even curious. Should you smash it with a nearby shoe? Or scoop it up in a cup and release it outside?

If that insect happens to be a kissing bug, you have another option-send it to Dr. Sarah Hamer and her research team at the Texas A&M College of Veterinary Medicine & Biomedical Sciences (CVM).

Kissing bugs-also known as cone-nose bugs, or triatomine insects-feed on human and animal blood. The insects are of particular interest to Hamer because of their potential to transmit the parasite Trypanosoma cruzi, which causes Chagas disease, a malady that can lead to acute or chronic heart disease or death in humans, pets, and wildlife. Acute heart disease is severe and has a sudden onset, while chronic heart disease develops over a long period of time.

There is a significant human health burden of Chagas disease in Central and South America and Mexico, where medical doctors are generally aware of the risk of disease. There is far less awareness for the disease in the U.S., despite estimates of over 300,000 infected people in the country.


While many of these individuals are likely to have contracted the disease in Latin America before moving to the U.S., there is increasing recognition for locally acquired human infections in the southern states, where infected kissing bugs are widespread. A growing number of dogs across the South are recognized to be infected, possibly from consuming infected bugs in the environment. While some infected dogs may live happy, health lives, others may die acutely or suffer chronic cardiac disease. Because there is no vaccine and treatment options are limited, efforts to control the vectors and parasite in nature may hold the key for disease prevention.

To better understand the risk of Chagas disease in the southern United States, Hamer and her team are taking an ecological approach to characterize the transmission cycles so that the parasite can be managed in nature before it spills over to humans and dogs. They are gauging infection and cardiac health status in pet dogs, working dogs, and shelter dogs across the state. And they are trapping kissing bugs to learn about their infection and feeding patterns across different regions.

When Hamer and her team started researching Chagas disease, they decided it was best to collect bugs from across Texas to address different research questions about the bug’s ecology. However, setting traps for the bugs was inefficient and did not provide enough for research; Hamer said her team often came up empty handed or had few bugs to work with from the field.

After talking to land owners, Hamer realized that many people are familiar with the kissing bug and have seen them on their property.

“People started hanging on to some of these bugs that they would see in their houses or in their dog kennels,” Hamer said. “They would put them in an old pill container or plastic bag and save them for us, and the next time we were out doing field work, we’d look at them.”

As the project grew to emphasize citizen science, the team’s research power expanded; citizen involvement granted the team access to more samples than they could ever dream of collecting themselves.

“We now have well over 3,000 bugs in our collection, which is bigger than any other collection of kissing bugs in the United States,” Hamer said. “Our students still are out actively trapping bugs, but we can’t match the effort of the citizen scientists. It’s huge, and it’s awesome.”

With so much citizen involvement, the program evolved to include outreach materials, such as a website with an interactive map to show where kissing bugs have been collected, informational pamphlets, and an established email account to answer questions and further include the public on the project. Hamer sees the outreach component as a way to educate the public about kissing bugs and protect the public’s health, as well as the health of pets and surrounding wildlife.


Dr. Sarah Hamer and Valery Roman-Cruz, MPh, examine kissing bugs.

While citizen scientists are often interested in knowing whether the bug they submitted is infected, Hamer says the result of any single bug is less informative than the overall epidemiology of the vectors. Finding an infected bug in the yard does not mean the family members or the family dog are at immediate risk for the disease but broadly suggests the region around the home is suitable for kissing bugs and Chagas disease, Hamer said. The team often educates the public specifically about how the disease is transmitted to help the public make decisions about their health.

In fact, Hamer said the route of transmission for Chagas disease can be rather inefficient-the cycle of the disease begins when a kissing bug feeds on the blood of an infected host. But unlike mosquitoes or ticks, kissing bugs cannot spread the parasite by simply biting another animal or person. Instead, the parasite occurs in the bug’s feces, and, therefore, the bug must defecate on a person or animal and the infected fecal material must be absorbed into the skin through the eyes, mouth, or a wound created by the kissing bug biting the victim. That series of events can be a rare occurrence, especially given a good standard of housing where bugs are unlikely to colonize inside the homes to reach people. However, oral transmission can also occur, and Hamer said dogs can contract the disease by consuming an infected kissing bug.

Once inside the new host, the parasite circulates in the blood for some time and then can infect different organs, including the heart, where it replicates, causing damage to the heart tissue cells. Over time, more and more heart tissue cells are destroyed, which can lead to heart disease.

While the effects of Chagas can be fatal, many infected individuals may never know they have been infected. It’s not possible to predict which infected individuals will suffer disease, and so physicians and veterinarians have a difficult time discussing the prognosis. Hamer said some people infected with Chagas may find out after donating blood, since blood banks now routinely screen for Chagas antibodies.

Because there is no cure for Chagas disease, only treatments to manage the symptoms, Hamer emphasizes that studying the parasite in bugs and wildlife can provide key data to protect the health of humans and dogs, and public outreach is a key component.

“We are working on a cell phone app as a future direction to enhance our outreach and research,” Hamer said. “People can upload pictures of their bugs and the app will time stamp it and mark it with location data. In addition, the app will also be a simple interface to get good information about kissing bugs and Chagas disease.”

The team is collaborating with other veterinarians, parasitologists, entomologists, geographers, diagnosticians, and public health officials at Texas A&M, the state health department, other universities-including in Mexico and Brazil-and the Centers for Disease Control and Prevention. Without collaboration and teamwork, Hamer’s research interests and efforts to educate the public about Chagas would not be possible.

To learn more and submitting a kissing bug to the TAMU Citizen Science Kissing Bug program visit kissingbug.tamu.edu.

Texas A&M’s Andersson, Research Team Observe New Species Among Darwin’s Finches

A team of scientists including Texas A&M University and Uppsala University professor Leif Andersson has discovered the origin of a new species of finch living among Darwin’s finches in the Galápagos archipelago.

Published on Thursday, Nov. 23, in the journal Science, their study reports that the new lineage was formed by the hybridization of two different species of Darwin’s finches.

Darwin’s finches provide an iconic model for the evolution of biodiversity on earth due to natural selection.



Big Bird lineage
A schematic illustration of the evolution of the Big Bird lineage on the Daphne Major island in the Galápagos archipelago. Initially an immigrant large cactus finch male (Geospiza conirostris) bred with a medium ground finch female (Geospiza fortis). Their offspring bred with each other and established the Big Bird lineage. —Photos © K. Thalia Grant for G. conirostris and Peter R. Grant for the remainder. Reproduced with permission from K. Thalia Grant and Princeton University Press, which first published the remaining images in “40 Years of Evolution” (P. R. Grant & B. R. Grant, 2014).

While conducting their field work on the small island of Daphne Major in 1981, Princeton University researchers Rosemary and Peter Grant observed an immigrant male that sang an unusual song and differed in size from all resident species on the island. Throughout their 40 consecutive years of direct observation, the Grants found that a new lineage, which they named the Big Bird lineage, was initiated when that male bred with a resident medium ground finch female.

The couple followed the new putative lineage for six generations, over 30 years. DNA sequence data now have revealed that the immigrant male was a large cactus finch, which, remarkably, must have flown to Daphne from Española island, more than 60 miles to the southeast.

The identification of the Big Bird lineage is significant because while a critical step in speciation is the establishment of reproductive isolation and the process of speciation is usually assumed to take a very long time, in the Big Bird lineage, it happened in just two generations, according to the Grants.

“The interesting aspect of this study is that a hybridization between two distinct species led to the development of a new lineage that after only two generations behaved as any other species of Darwin’s finches,” said Andersson, a visiting professor in the Texas A&M College of Veterinary Medicine & Biomedical Sciences’ (CVM) Department of Veterinary Integrative Biosciences (VIBS) and an author on the study. “If a naturalist had come to Daphne Major island without knowing that this lineage arose very recently it would have been recognized as one of the four species on the island. This clearly demonstrates the value of long-running field studies.”

Traditionally, good species respect species boundaries and cannot produce fully fertile progeny if hybridization happens, as is the case for the horse and the donkey, for example; however, in recent years, it has become clear that some closely related species that normally avoid breeding with each other exchange genes by hybridization surprisingly often.

The study’s authors have previously reported that there has been a considerable amount of gene flow going on among the 18 species of Darwin’s finches for thousands of years. All 18 species have been derived from a single ancestral species that colonized the Galápagos 1-2 million years ago.

“It is very likely that new lineages, like the Big Birds, have originated many times during the evolution of Darwin’s finches,” Andersson said. “The majority of these have gone extinct, but some may have led to the evolution of contemporary species. We have no idea about the long-term survival of the Big Bird lineage, but it has the potential to become a success and it provides a beautiful example of one way in which speciation occurs. Charles Darwin would have been excited to read this paper.”

The Big Bird lineage was identified because of the unique song of the original immigrant male, since sons learn the song of their father and females mate with males that sing like their fathers, according to the Grants, who are also listed as co-authors of the study.

The new lineage also differed from the resident species in beak morphology—often occurring in order for a lineage to be ecologically competitive—which is also a major cue for mate choice. In the case of the Big Bird lineage, its beak morphology evolved from that of the immigrant finch to allow the species to utilize different food sources on the Galápagos.

“It is very striking that when we compare the size and shape of the Big Bird beaks with the beak morphologies of the other three species inhabiting Daphne Major island, the Big Birds occupy their own niche in the beak morphology space,” said Sangeet Lamichhaney, a post-doctoral fellow at Harvard University and co-author on the study. “Thus, the combination of gene variants contributed from the two interbreeding species in combination with natural selection led to the evolution of a beak morphology that was competitive and unique.”

The study was supported by the Galápagos National Parks Service, The Charles Darwin Foundation, the National Science Foundation, the Knut and Alice Wallenberg Foundation, and The Swedish Research Council.

Dr. Kate Creevy: Research, In Dog Years

Aging is a universal experience, shared by both humans and animals. But many mysteries still surround the aging process. Now, a collaborative project between the Texas A&M College of Veterinary Medicine & Biomedical Sciences (CVM), the University of Washington, and other colleges and organizations is set to chip away at these mysteries to better understand how our canine companions age both physically and mentally.

Dr. Kate Creevy and Poet
Dr. Kate Creevy and Poet

The Dog Aging Project is an innovative proposal to study aging in pets, to benefit their health and longevity, according to Dr. Kate Creevy, chief veterinary officer on the Dog Aging Project and associate professor at the CVM.

“The things that we can learn about dogs to benefit them also can benefit people,” she said. “We hope that our interest in studying the dog for its own sake provides terrific benefit to people, as well.”

Starting with understanding and characterizing how dogs age, the project seeks to build upon what little information currently exists to describe normal aging in various sizes and breeds, Creevy said. This not only will help veterinarians better treat aging canines, but it will help researchers understand conditions such as diabetes and arthritis that affect both dogs and humans as they age.

Dogs of All Shapes and Sizes

Approximately 10,000 dogs of varying ages and breeds living throughout the United States will be enrolled in the project, accounting for a sample size that is representative enough to describe aging in a typical dog. The study will take a long-term look at the health of dogs in their natural environment over five to 10 years, making middle-aged dogs particularly valuable candidates for the study.

Enrolled dogs will live out their days as they normally would, seeing their regular veterinarians, which will allow dogs across the country to conveniently participate.

They will be divided into two subsets, a more closely monitored group and a less closely monitored group. Each group will contribute unique data to the project.

For the closely monitored group, local veterinarians will collect regular blood and urine samples that will be sent to Creevy and her team, who will also assess the dogs’ medical records and remain in close contact with the veterinarians. Researchers also will regularly communicate with owners about their dogs’ routines.

The less-closely monitored subset comprises dogs that will provide genetic samples, which will help the research team understand the genetic origins of age-related diseases. Researchers also will monitor the dogs’ medical records.

“It is our goal to make the portion of the dogs who are closely monitored a larger and larger group by continuing to obtain additional funding,” Creevy said.

Exercising Body and Mind

Because activity levels are known to influence health, the Dog Aging Project also will use monitors to measure levels of activity, heart rate, and other vital parameters in some dogs. Using accelerometers will provide the researchers with important health information about the dogs’ activity levels, which likely also will be of interest to owners, Creevy said.

“We will be interested in that data for research, but the owners also will have access to that data,” she said. “For example, if an owner wants to know how much her dog runs around the house when she’s not home, she can.”

Physical health is not the only thing that the researchers are investigating; the Dog Aging Project also aims to understand and characterize how dogs’ brains age. Through the project, owners will have access to a website that allows dogs and owners to play various games to assess different aspects of cognition.

“It’s not about whether your dog is smarter or dumber; it’s about how your dog thinks and if certain breeds and ages of dogs tend to think the same way,” said Creevy, adding that the tests will allow owners to bond with and understand their dogs.

The Big Picture

Creevy’s research is a first step in providing a foundation for future canine aging research. The field is so cutting-edge, many of its questions have yet to be discovered.

“We won’t really know what some of the data means at the time that we collect it,” she said. “We won’t know what it means until we’ve captured the information from a lot of dogs and have had time to see how their lives unfolded.

“(Likewise) Some of the information we’ll be giving back to owners won’t be of immediate use to them, but as the research progresses and some of that information develops new meanings, they’ll be able to use the information to better understand their dogs,” Creevy said.

By providing this fundamental knowledge, the Dog Aging Project has the potential to help support a new field in veterinary medicine-geriatrics.

“One of the things that’s true about veterinary medicine is we do not currently have a specialty in geriatrics the way they do in human health,” Creevy said. “Certainly as people age, you see a gerontologist. We do not currently have a specialty of veterinary gerontology. Defining what the typical or normal old dog looks like is our first challenge.”

Creevy also anticipates people becoming more aware of the Dog Aging Project and to have future collaborations with groups that want to further examine certain variables, such as diet, exercise, and even certain medications. These variables could impact canine aging and, in turn, affect human aging.

New Tricks

In many ways, dogs mirror their owners. By sharing the same habits, dogs can serve as a model for human conditions, such as obesity, cancer, and arthritis. But dogs are not only helping people; people are helping dogs, as well.

“We have chosen to use models from human medicine to identify some of the diseases we think are going to be the most important to healthful aging, because the diseases that dogs experience in aging are, in many ways, very similar to people,” Creevy said. “Obesity is a big problem for dogs, just as it is for people in this country. Cancer is a big problem for dogs, just as it is for people in this country. They get low thyroid function or hypothyroidism. We consider all of those to be very, very important diseases of dogs.”

Creevy said aging sometimes can be associated with dogs losing interest in daily life, becoming difficult to interact with, and losing normal control of food and bathroom times. These things can be a challenge for aging people, as well.

“Trying to understand dogs who end up experiencing those conditions, versus the dogs who don’t, may lead to some way we could interact with dogs younger in life to decrease the likelihood of these outcomes,” Creevy said.

Ultimately, it’s the love humans have for their dogs that helps push the research forward, Creevy said.

“We’re trying to be on the cutting edge, and I think we are inspired by the fact that dogs are so important to people,” she said. “There is no limit to the things owners would do to try to promote healthy, enjoyable lives for their dogs. Because that’s true, we’re capable of pushing the research envelope and asking questions that haven’t previously been asked because dog owners are willing and able to help us.”

Texas A&M Receives NIEHS Superfund Grant to Conduct Environmental Research

COLLEGE STATION, Texas – Texas A&M Superfund Research Center scientists from across campus will conduct four environmental research projects funded by a five-year, $10 million grant from the National Institute of Environmental Health Sciences (NIEHS).



One of the Superfund Site signs in the Houston Ship Channel
One of the Superfund Site signs in the Houston Ship Channel

Established in 1987, the NEIHS Superfund Research Program is a highly competitive grant-based program that funds a network of 16 university-based multidisciplinary research teams that study human health and environmental issues related to hazardous chemicals, with a goal of understanding the link between exposure and disease.

Texas A&M Superfund Center researchers, led by Dr. Ivan Rusyn, professor in Department of Veterinary Integrative Biosciences in the College of Veterinary Medicine & Biomedical Sciences (CVM), and Dr. Anthony Knap, professor of oceanography and director of the Geochemical and Environmental Research Group in the College of Geosciences, will work to translate science into the practice of mitigating the health and environmental consequences of exposure to hazardous chemical mixtures.

“We’re a new center, so it’s a major accomplishment to join NIEHS grantees who work on Superfund, and we should be proud of that,” Rusyn said. “The reviewers said that our program was clearly one of those examples of when the entire program is even greater than the sum of its parts.”

Four projects, all part of the grant, will stem from a case study of a major storm coming through Galveston Bay and the Houston Ship Channel, examining the chemicals found within the sediment to understand the complexities of hazardous chemical exposures and potential adverse health impacts.

“There are a hundred years of chemicals in the sediment in the Galveston Bay due to the shallow depth, the proximity to a densely populated area, and concentration of many industries. A hurricane or major storm will dislodge and mobilize many of the legacy chemicals in that sediment and eventually deposit it on land. That creates a completely new contamination and human exposure scenario,” Knap said. “When that happened with Hurricane Ike almost 10 years ago, the local and state authorities had to act on general, standard procedures, not the most relevant scientific evidence about this particular event.”

“Environmental emergencies create issues that need to be solved right now, we cannot afford to just tell people to wait 50 years. It can’t be ‘we’ll figure it out,’” Rusyn said. “Decisions need to be made quickly and based on sound science, a challenge that our center will address.”

The ultimate goal of the program is to create packages that will serve as “how-tos” for affected areas during any form of environmental emergency situation, from weather-related disasters, to chemical spills, to industrial accidents.



Mya Morales
Mya Morales, Texas A&M student, testing water in the bay.

“We’re developing tools that can quickly determine the type of hazard and which concentrations could cause a problem,” Knap said. “This is where a ‘whole mixtures’ theme is important, because traditional decision-making is done one chemical at a time, but humans are exposed to mixtures of chemicals and, especially in these emergency situations, we don’t know the identities of the individual chemicals or their potential toxicities.”

Texas A&M Superfund researchers represent the Colleges of Veterinary Medicine & Biomedical Sciences, Medicine, Geoscience, Engineering, and Science; the School of Public Health; and the Texas A&M Health Science Center. Partners also include North Carolina State University, the University of North Carolina—Chapel Hill, Baylor College of Medicine, and the federal Pacific Northwest National Laboratory.

“Texas A&M has a tradition of high-impact research,” said Dr. Eleanor Green, the Carl B. King Dean of Veterinary Medicine at Texas A&M. “This NIEHS grant is a product of Dr. Rusyn, scientists from across Texas A&M’s campus, and partners from across the country coming together to collaborate with excellence. Dr. Rusyn is one of our President’s Senior Hires supported by the Chancellor’s Research Initiative, an initiative that successfully attracts world-renowned scholars and researchers. This grant not only demonstrates a commitment to one health, but also takes an innovative and timely approach to offer solutions to potential environmental disasters such as Hurricane Harvey, to mitigate the health and environmental consequences of exposure to people and to animals. The CVM is proud of this incredible team of researchers, led by our own Dr. Rusyn.”

Rusyn said the program wouldn’t be possible without the support of Texas A&M and the Texas A&M Office of the Vice President for Research, which provided additional resources that enabled the center to fund pilot projects, facilitate interactions within the center, support diversity in training, and offer “boot camp” exercises to demonstrate the use of new tools and approaches.

“The institutional support we have received from Texas A&M is something that is just unparalleled in this current environment,” he said. “This university’s support has been spectacular in that regard, and I am delighted to be part of the institution that encourages team science at the national level.


More about this project will be available in the next edition of CVM Today magazine, which will be published later this month.

For more information about the Texas A&M College of Veterinary Medicine & Biomedical Sciences, please visit our website at vetmed.tamu.edu or join us on Facebook , Instagram , and Twitter.

Contact Information: Megan Palsa, Executive Director of Communications, Media & Public Relations, Texas A&M College of Veterinary Medicine & Biomedical Sciences; mpalsa@cvm.tamu.edu ; 979-862-4216; 979-421-3121 (cell)

Texas A&M Professor Receives Grant for Lifesaving Childhood Cancer Research

Dr. Heather Wilson-Robles, an associate professor and the Dr. Fred A. and Vola N. Palmer Chair in Comparative Oncology in the Texas A&M College of Veterinary Medicine & Biomedical Sciences’ (CVM) Small Animal Clinical Sciences Department, has been awarded a $94,255 research grant from the St. Baldrick’s Foundation.


Dr. Heather Wilson-Robles
Dr. Heather Wilson-Robles

“Dr. Wilson-Robles is a quintessential clinician-scholar whose independent and collaborative discoveries are carving the path to a better understanding of cancer and, ultimately, to effective cancer treatments in canine patients that will eventually translate to human patients,” said Dr. Eleanor M. Green, the Carl B. King Dean of Veterinary Medicine at Texas A&M University.

Wilson-Robles’ grant is one of 90 given to professors from across the country by St. Baldrick’s Foundation. The foundation is providing $23.5 million in its summer grant cycle to support the brightest minds in the pediatric cancer field.

“For nearly a decade, Dr. Wilson-Robles has conducted leading-edge clinical trials that impact human and animal health,” said Dr. Jonathan Levine, department head, professor, and Helen McWhorter Chair in Small Animal Clinical Sciences. “This grant represents an exciting extension of her work on bone cancer, this time exploring the lethal spread of tumor cells to other sites in the body.”

Her project, funded through June 2018, will examine a new drug that targets the cells that spread; this process has shown promise as a therapy.

“Bone cancer is an aggressive disease in both children and pet dogs that can be painful and often leads to death of the patient even with aggressive surgery and chemotherapy,” Wilson-Robles said. “Most often these patients die because the tumor has spread to other areas of the body, not from the original bone tumor, which is often removed with surgery. Therefore, in order to better battle this disease, new therapies that target the cells that spread are needed.

“Our goal is to more thoroughly investigate this drug for its ability to prevent or delay spread of the tumor cells using both human and dog bone tumor cells,” she said.

Every two minutes a child is diagnosed with cancer worldwide. One in five kids diagnosed in the U.S. will not survive, and of those who do, two-thirds will suffer from long-term effects from the very treatment that saved their life; each phase of the research process, from the laboratory to translational research to clinical trials, plays a crucial part in developing new therapies that will give kids with cancer the healthy childhoods they deserve.

“St. Baldrick’s leads the charge to take childhood back from cancer and is dedicated to funding the best research, no matter where it takes place,” said Kathleen Ruddy, CEO of the St. Baldrick’s Foundation. “Through our grants, we are proud to support world-class experts of today, as well as the next generation of researchers whose innovative approaches employ cutting-edge technology and emerging science to find cures and treatments to create a growing generation of childhood cancer survivors.”

The St. Baldrick’s Foundation, is a volunteer-powered charity dedicated to raising money for  childhood cancer research.

To learn about other research St. Baldrick’s is funding, visit the  grants search page here.

Texas A&M Professor Explores Why Peruvian Parrots Eat Clay

For more than 16 years, researchers and volunteers have been observing wildlife along the clay cliffs of Southeastern Peru’s Tambopata River. They’ve gathered data every day, logging more than 20,000 hours and building one of the most extensive datasets on tropical parrots in the world.



Dr. Donald Brightsmith
Dr. Donald Brightsmith

In a new paper published in Ibis, Elizabeth Hobson, a postdoctoral fellow with the Arizona State University-Santa Fe Institute Center for Biosocial Complex Systems, and Donald J. Brightsmith, a professor in the Texas A&M University College of Veterinary Medicine & Biomedical Sciences (CVM) and director of the Tambopata Macaw Project, begin to analyze the data from this long-term study.

In particular, the two explore the potential drivers behind geophagy—or intentional soil consumption—they’ve regularly observed in 14 different parrot species there.

This region of the Tambopata River in Southeast Peru is an ideal spot to study the nearly two-dozen parrot species that live nearby in the Amazon rainforest. In the thick foliage of the jungle, the birds are difficult to see, but when they emerge to gather up beakfuls of the sodium-rich clay soil, “it’s a crazy, screaming kaleidoscope of color,” Hobson said.

“They’re all quiet when they take flight, but in a few seconds, they all begin to scream, and some drop bits of the clay from their mouths,” said Brightsmith, who has led the Tambopata Macaw Project since 1999. “It’s an incredible experience.”

But geophagy is a somewhat confounding behavior—clay soil is basically inert.

“It doesn’t have proteins, carbohydrates, or really anything that you’d need,” Brightsmith said. “If we can understand why it’s so important to these parrots, we can learn more about the ecosystem and how it affects the other insects, birds, and mammals who also eat this soil.”

Geophagy occurs around the world and in many types of animals, and scientists have proposed many explanations for the behavior. In their paper, Hobson and Brightsmith explore the two leading theories for these Amazonian parrots—that clay soils help protect the birds from food toxins when ideal food sources are scarce and that clay soils provide necessary minerals not available in the parrots’ regular diet.

Like previous studies, their analysis suggests that toxin-protection is not a driver. But parrot geophagy there is highly correlated with breeding season, suggesting the increased nutritional demands are likely behind the soil consumption. This study also joins a large body of research suggesting that hunger for sodium, specifically, is that driver.

“There’s lots of evidence that’s pointing in that direction,” Hobson said. “Sodium in the rainforest is really rare, and the place on these clay licks most preferred by the birds also has the highest sodium content.”

Understanding how nutritional needs are—and are not—being met during breeding season becomes even more important in light of climate change, according to Brightsmith. Some of the larger macaws are already breeding right before a seasonal crash in food supply, requiring parents take their fledgling young on long flights to find food.

“If climate change starts messing with the macaw’s food supply, it could disrupt their ability to breed,” he said.

Texas A&M Professor Works with NIH-Supported Scientists to Elicit Broadly Neutralizing HIV Antibodies

A team of scientists including Texas A&M College of Veterinary Medicine & Biomedical Sciences (CVM) associate professor of immunology Dr. Michael Criscitiello have achieved a significant step forward in HIV research, eliciting broadly neutralizing antibodies (bNAbs) to the virus by immunizing calves.



Dr. Michael Criscitiello
Dr. Michael Criscitiello

The National Institutes of Health (NIH)-supported scientists reported the findings in a paper published online July 20 in the academic journal Nature. Those findings offer insights for HIV vaccine design and support further study of modified bovine antibodies as HIV therapeutics or prevention tools in humans.

Researchers have observed that about 10-20 percent of people living with HIV naturally develop neutralizing antibodies to the virus, but usually only after nearly two years of infection. These neutralizing antibodies have been shown in the laboratory to stop most HIV strains from infecting human cells and to protect animal models from infection.

However, scientists have so far been unsuccessful in prompting the human immune system to produce these antibodies through immunization. Further, while bNAbs isolated from people with HIV infection have demonstrated promise in primate studies and have entered human studies for HIV prevention and treatment, questions remain about whether effective antibodies could be produced rapidly and at a scale suitable for widespread distribution.

The researchers have determined that cattle may offer some help in solving these problems.

“This work is exciting because a structural and genetic oddity in cattle antibodies appears to allow them to easily and quickly make effective antibodies to HIV that humans cannot,” Criscitiello said. “The cattle antibodies may themselves be useful—with a few tweaks—in humans.”

While bovine neutralizing antibodies are not likely suitable for clinical use in humans in their current form, exploring this rapid production may help answer important research questions.

“From the early days of the epidemic, we have recognized that HIV is very good at evading immunity, so exceptional immune systems that naturally produce broadly neutralizing antibodies to HIV are of great interest—whether they belong to humans or cattle,” said Dr. Anthony S. Fauci, NIAID director.

“We never dealt with the entire HIV virus here (at Texas A&M), but the cattle received immunizations containing a protein designed to mimic a surface protein on HIV,” said Criscitiello, who coordinated the A&M efforts with Scripps, managed the animal work, and analyzed the antibody immunogenetics.

While no one knows definitively why these powerful antibodies evolved in cattle, one theory holds that the animals’ long HCDR3 loops are tied to their extensive gastrointestinal systems. Cattle and other ruminant animals have multi-chambered stomachs and a robust population of bacteria in their digestive tracts to help break down a diet of tough grasses. However, these bacteria can pose an infection risk if they escape the gut, so cattle with a versatile mechanism for producing potent antibodies would greatly benefit from the increased protection.

“A minority of people living with HIV produce neutralizing antibodies, but only after a significant period of infection, at which point virus in their body has already evolved to resist these defenses,” said Dennis R. Burton, Ph.D., a lead author on the study, director of the NIH’s Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery and scientific director of the IAVI Neutralizing Antibody Consortium at the Scripps Research Institute. “Unlike human antibodies, cattle antibodies are more likely to bear unique features and gain an edge over complicated HIV immunogens.”

Further study on how this mechanism contributed to the elicitation of bNAbs to HIV in cattle may inspire novel approaches to HIV vaccine development.

“HIV is a human virus,” said Devin Sok, a study leader and IAVI collaborator at the Scripps Research Institute, “but researchers can certainly learn from immune responses across the animal kingdom.”

Researchers may also explore mimicking or modifying the potent isolated bNAb, or those like it, to develop antibody-based HIV therapeutics and prevention tools, as well as treatments for other pathogens that have evolved to avoid human antibody responses. Because the current research indicates that the bovine immune system may typically work quickly to produce effective antibodies against difficult pathogens such as HIV, immunizing cattle and discovering such antibodies may become a useful approach to ensure these tools are readily accessible.

To read the full report in Nature, visit http://www.nature.com/nature/journal/vaap/ncurrent/full/nature23301.html, and to see the full press release, visit the National Institute of Allergy and Infectious Diseases website at https://www.niaid.nih.gov/news-events/nih-supported-scientists-elicit-broadly-neutralizing-antibodies-hiv-calves

It’s Safe to Say–Impact Begins at Discovery

Discovery and the unexpected—these are recurring themes in the research career of Dr. Stephen Safe, a distinguished professor at the College of Veterinary Medicine & Biomedical Sciences (CVM). Trained as a chemist, Safe eventually found himself studying toxicology and examining the biochemical mechanisms of cancer with the hopes of developing effective drug treatments.



Dr. Stephen Safe
Dr. Stephen Safe

Safe looks at receptors, a molecular lock to which chemical signals are the keys. When these chemical signals bind to the receptor, or turn the metaphorical key, it leads to a Rube Goldberg–like process, where one action affects another and then another, ultimately powering various biological processes.

“Receptors are needed for life,” Safe said. “They are sensing molecules. They sense light. For example, you need sunlight to produce Vitamin D. What does Vitamin D do? It would do nothing if there wasn’t a Vitamin D receptor.”

And, it all started with a single receptor—the aryl hydrocarbon, or AH, receptor. Known to play a role in a chemical’s toxicity in the body, the AH receptor was not known for its health benefits. However, research trends led Safe and his colleagues to suspect that this receptor’s function was far from black and white. There were, in fact, health benefits yet to be uncovered.

“I started off working on toxic compounds that bound to the AH receptor. It was always thought to be a receptor that was important for driving toxicity of various chemicals that bound to it,” Safe said. “Many people have discovered in the last 20 years that this receptor plays a huge role in all sorts of things, including the health of your gut, the health of your skin, and autoimmune diseases. We’ve been looking at ligands—or compounds that bind this receptor—that aren’t toxic. We’re using them for treating cancers, and investigating the heath benefits of the receptors in gut microbiota.”

Excited by the possible health benefits associated with the AH receptor, Safe began looking for practical solutions to ailments such as pancreatic cancer. Through partnerships with pharmaceutical companies, Safe is working toward developing effective drug treatments that would specifically focus on receptors like the AH and NR4A1 receptors to promote pathways that prevent cancer growth. “We’ve got a new group of drugs that look like they’re really going to knock your socks off,” Safe said.


Dr. Safe and his team
Dr. Safe with his research team in the laboratory

Safe’s interest in the AH receptor has stimulated an interest in other receptors, such as NR4A1, which Safe and his colleagues are investigating for the treatment of multiple cancers including rhabdomyosarcoma—a devastating children’s cancer. “We think the AH and NR4A1 receptors are really important in cancer, and we’ve been developing drugs that target them through different pathways,” he said.

Developing these drugs can be a balancing act, looking for the appropriate dose to ensure effectiveness. “We’re trying to develop drugs that we can give at a much lower concentration to hopefully be below the toxic threshold. We think that they have relatively low toxicity and expect that the side effects will be minimal. In addition, they’re also useful for combination therapies.”

Safe’s fascination with the AH receptor has caused his research to take an unexpected turn. In collaboration with other researchers at Texas A&M, he is focusing on the effects of microbial and food-derived AH-receptor compounds on gut health. For example, eating cruciferous vegetables, such as cabbage, could provide similar effects as the compounds acting on the AH receptor. “Maybe plants that produce a lot of AH receptor compounds, like cruciferous vegetables, which are known to be health-protective, could be combined with what the microbiota produces. The two in combination could be dynamite,” he said.

The twists and turns of Safe’s research has led to continuous learning and a deep curiosity. “The good thing for me is I started off as a chemist and all we do in my lab is oncology and molecular biology. So, I’m learning all the time,” he said. Beyond the AH receptor discovery, Safe continues to search for much needed practical, life-saving therapies.

Strengthening Foal Immune Systems, Preventing Pneumonia

Dr. Noah Cohen, professor and associate department head for research and graduate studies in the Department of Large Animal Clinical Sciences at the Texas A&M College of Veterinary Medicine & Biomedical Sciences (CVM), is leading the search for an effective strategy to prevent diseases caused by Rhodococcus
(R. equi), a bacterium that commonly causes diseases in foals and in humans and animals with suppressed immune systems.


Dr. Noah Cohen

R. equi may not always cause disease in an infected animal, but when it does, pneumonia is most often the disease that develops. R. equi frequently infects the lungs of foals, causing severe symptoms, such as fever and coughing, which can potentially lead to death. In addition to disease in the lungs,
R. equi can affect bones, kidneys, the intestinal tract, and other parts of the body.

To combat this potentially deadly pathogen, clinician-scientists like Cohen are working to develop strategies other than antibiotics that stimulate the patient’s immune system to help protect them from infection.

Coming to the CVM

In 1988, Cohen came to the CVM as an assistant professor in veterinary public health. However, his interest in applying epidemiology to large animal medicine soon led him to a residency in large animal internal medicine at the CVM. “I was honored and excited about my residency,” he said. “There were outstanding equine internists at Texas A&M, including Drs. Kent Carter, Joe Joyce, Tom Kasari, Bill McMullen, Dub Ruoff, and Allen Roussel. I knew that the excellent clinical training would enable me to identify critical questions for research. The opportunities and clinical questions seemed endless.”

Before he started his residency, Cohen had the opportunity to meet Dr. Ronald J. Martens, the department head of what is now the Department of Large Animal Clinical Sciences. Several years before Cohen came to the CVM, Martens founded the Texas A&M Equine Infectious Disease Laboratory (EIDL) to combat infectious diseases such as those caused by R. equi. Martens’ work in infectious diseases as a clinician-scientist inspired Cohen to complete his residency and join the faculty of the CVM.

“Dr. Martens had the vision to recognize that a clinician-scientist with an interest in epidemiology would be of benefit to the department,” Cohen explained. “He encouraged me to complete my residency training in internal medicine, and then he recruited me to become a member of the large animal medicine faculty.”

After he completed his residency, Cohen began researching R.equi in the EIDL under the direction of Martens. The main goal of Martens’ research was to find an effective preventative measure against infections caused by R. equi in foals because none previously existed.

Treating pneumonia caused by R. equi can be difficult because treatment is lengthy, expensive, must be administered multiple times daily, can cause serious side-effects, and isn’t always effective. This is why Martens began working on ways to decrease foals’ susceptibility to developing disease from the bacteria.

On breeding farms, pneumonia caused by R. equi is the most common and severe form of pneumonia in foals that are between the ages of one and six months. Pneumonia is a leading cause of disease and death for foals, which has motivated researchers like Martens and Cohen to seek an effective preventative strategy against pneumonia caused by R. equi. A vaccine to directly prevent the disease would be a major breakthrough for the health of foals on breeding farms, according to Cohen.

Martens recognized the prevalence of R. equi in foals and knew the importance of preventing R. equi–related diseases, especially pneumonia. Martens’ biggest contribution to the prevention of R. equi disease was the use of hyperimmune plasma, which is harvested from the blood of horses that were vaccinated to produce high concentrations of antibodies againstR. equi. The plasma is then transfused to foals. These transfusions partially protect foals against infection with R.equi.

“The collection and transfusion of plasma that is hyperimmune against R. equi remains the only acceptable and commercially available approach for preventing R. equi pneumonia,” Cohen said. “Unfortunately, it is not completely effective and has some other limitations, such as being expensive, labor-intensive to administer, and carrying some health risks for foals. Although the concept of preventing the disease by administering antibiotics has been demonstrated to be effective, this approach isn’t acceptable because it isn’t uniformly effective and, most importantly, can contribute to antibiotic resistance from overuse.”

Martens was also interested in identifying alternatives to traditional antibiotics to control R. equi pneumonia because of emerging resistance to drugs commonly used to treat the disease. When Martens retired, he passed on the directorship of the EIDL to Cohen.


Dr. Cohen and students work with an equine patient.

Exploring alternative treatments of R. equi pneumonia as opposed to traditional antimicrobial drugs remains an area of interest for the EIDL. “We are working on two strategies for preventing R. equi pneumonia based on having the patient’s immune system protect them from infection rather than antibiotics,” Cohen said. “First, we are working on developing a vaccine, which is a traditional and effective approach for preventing infections. Second, in collaboration with investigators from the Texas A&M University System’s Institute for Biosciences and Technology (IBT) in Houston, we are investigating if a mist inhaled into the lungs can stimulate a foal’s immune system to protect it against R.


The CVM’s collaboration with numerous researchers worldwide is a critical component of Cohen’s goal to prevent R. equi pneumonia in foals. Cohen has collaborators in Brazil, Canada, Germany, Japan, and other countries, all of whom have contributed to the growing research in R. equi pneumonia prevention.

In addition, Cohen said his research project benefits significantly from many researchers in the United States and the CVM. “We collaborate with numerous investigators from many countries,” he explained. “We work especially close with Dr. Steeve Giguère from the University of Georgia, one of the world’s authorities on this disease. We are also fortunate to benefit from many scientists at the CVM.”


To reduce the risk of antibiotic resistance, Cohen and his team are investigating new drugs and potential methods of administering preventative and therapeutic agents. After over five years of trying, Cohen and his team at the CVM have produced encouraging results with a vaccine for R. equi pneumonia.

“We are exploring new approaches that we hope will be effective and not promote antibiotic resistance in R. equi,” Cohen said. “Examples include using inhaled substances that facilitate the foal’s own immune system by stimulating receptors of the immune system that eliminate R. equi, and drugs such as metal-based compounds and antibiotics that will reduce the risk of resistance.”

One Health

The strategies Cohen and his team are exploring may have positive implications for other animals, including humans. Since there are striking similarities between R. equi and Mycobacterium tuberculosis, the bacteria that causes tuberculosis (TB), their research on R. equi may give rise to potential therapies or preventives against TB in humans.

“Our vaccine research on R. equi might be an appropriate strategy for preventing TB, which would be of global importance for human health,” Cohen explained. “Additionally, the strategy developed by Dr. Gerald Pier and his colleagues at the Harvard Medical School, with whom we collaborate, is innovative and could lead to a ‘broad-spectrum’ vaccine that is effective against many infectious agents.”

The One Health Initiative, which stresses the connection between animal health, human health, and the environment, is an integral part of Cohen’s research. “Although our hearts and minds are committed to improving equine health, we are very much engaged in the One Health Initiative with our activities,” he said. “Developing new types of antibiotics and vaccines that can reduce the need for antibiotics is important for equine and human health because bacterial diseases remain important causes of disease for all species, and the emergence of antimicrobial resistance is a global health crisis in veterinary and human medicine.”

Research Support

As Cohen continues his research on R. equi, he links his accomplishments and new findings to the support that Martens provided him when he began his journey at the CVM. Martens was more than an administrator or a clinician-scientist for Cohen to look up to; he was a mentor.

“I learned so much from him, and we worked synergistically,” Cohen said. “One of the most important things I learned from Dr. Martens was that research is always better when done as a team. Martens was a role model for leadership, and he helped create a work environment in which we could work passionately, assiduously, and enjoyably. He offered advice and humor that made it fun to come to work each day.” In addition, Cohen expressed his gratitude for the cooperation and support from everyone at the CVM because it has positively impacted the success of his research.

Before retirement from the CVM, Cohen hopes to develop a vaccine to control R. equi pneumonia because “it is of global importance.” He would like to help shift the emphasis of treating infectious bacterial disease with antibiotics to methods that help the patient’s immune response protect them against infection. This is of utmost importance because bacteria are rapidly developing resistance to antibiotic treatment.

Cohen also recognizes the significance of students, believing they are the leaders of tomorrow. He aspires to make a positive impact on students by encouraging their research efforts. “During my time at the CVM, I would like to have trained scientists, including veterinary clinician-scientists, whose future contributions will far surpass mine,” he said.

More About Dr. Noah Cohen

Cohen’s interest in veterinary epidemiology and large animal internal medicine led him to the CVM, where he began researching R. equi in the late 1980s; however, his passion for epidemiology developed during his childhood.

“I was born in Pennsylvania, but I spent my middle school and high school years in Switzerland and Israel because of my father’s work,” Cohen said. “My father was a veterinarian who was interested in zoonotic diseases, and this strongly influenced my career. He worked for many years at the University of Pennsylvania’s School of Veterinary Medicine. I spent a lot of time at the Bolton Center, the university’s large animal hospital, where I fell in love with the idea of being an equine veterinarian.”

Cohen attended the University of Pennsylvania where he earned his undergraduate degree in oriental studies with a minor in biology and his VMD (Veterinariae Medicinae Doctoris). After he earned his VMD, Cohen spent over two years in private equine practice in and around Toronto and Ontario, Canada. He then earned his MPH and Ph.D. in epidemiology from the Johns Hopkins University School of Hygiene and Public Health, now known as the Bloomberg School of Public Health.

“At Penn, I benefitted greatly from a liberal arts education and the challenge to think and work independently,” Cohen explained. “In veterinary school, I had teachers whose expertise and dedication to excellence inspired my career. At Johns Hopkins, I was exposed to clinical and research excellence, and the principle that optimal clinical medicine and biomedical research are inextricably linked.”

Cohen continued, “I was trained by superb clinicians and fellow residents in the art and science of clinical medicine at Texas A&M. I also learned about the extraordinary commitment that clinical faculty have for teaching veterinary students. My mentors at Texas A&M instilled in me the ‘students first’ attitude that is a cornerstone of Aggie education. I cherish each of these three institutions for enabling me to do what I love: to teach, to learn, and to help others reach their goals.”

Spinal Cord Study Finds Drug Can Change Bladder Function in Dogs, Possibly Humans


Levine Dexter
Dr. Jonathan Levine with Dexter

Texas A&M University and University of Texas at Austin researchers have discovered that in dogs with naturally occurring spinal cord injury, a drug that blocks matrix metalloproteinases (MMPs) allows the bladder to stretch more easily as it fills.  Such a change will likely reduce the discomfort that is commonly associated with the inability to void urine after spinal cord injury and may improve bladder function.

This clinical trial, evaluated 93 dogs that sustained naturally occurring spinal cord injuries resulting from disc herniation.  These injuries are most common in dachshunds, a breed that has a 20 percent lifetime risk of developing disc herniation, which can often cause sudden spinal cord injuries, according to Dr. Jonathan Levine, a professor of neurology and neurosurgery and department head of Small Animal Clinical Sciences in Texas A&M’s College of Veterinary Medicine & Biomedical Sciences (CVM).

“This breed has degeneration of their discs, including changes like dehydration and mineralization, starting early in life,” Levine said. “Because they have this early onset degeneration, dachshunds are set up to have disc herniation at a higher rate than other breeds.

“For a dachshund, these disc herniations consist of rapid displacement of the disc and bruising plus compression of the spinal cord,” he said.

This clinical trial, funded by the U.S. Department of Defense and published in the 2017 May issue of the Journal of Neurotrauma, was based upon earlier studies led by Linda Noble-Hauesslein at the University of Texas at Austin, in collaboration with colleagues at the University of California at San Francisco.  Those early study were the first to demonstrate that MMPs, present in the injured spinal cord, contributed to the long-term loss of function after spinal cord injury.  These encouraging findings led to the two-cohort clinical trial in spinal cord injured dogs in which Levine and his team administered the MMP inhibitor GM6001 to one set of dogs and provided a placebo to another set.

It is often difficult to empty the bladder after spinal cord injury and this can result in an increase in pressure within the organ. Using a technique called cystometry, the researchers measured the pressure in the bladder and found that dogs treated with GM6001 showed a greater capacity to stretch in response to filling (called compliance).

“We were trying to figure out how they recover from a urinary standpoint. Nobody knew. We knew a little bit just observing the dogs, whether they urinated again or not after their injuries,” Levine said. “What we found was that dogs that got the drug had bladders that were a little more forgiving, or a little more stretchy, compared to dogs that didn’t.”

The results, according to Levine, have significant implications for humans with spinal cord injuries as well.

“These injuries are actually very similar to traumatic spinal cord injuries in people, where there is compression and bruising of the cord,” he said.  “People with injuries often have bladders that don’t stretch very well, so they might fill just a small amount of urine and then they have to empty. They have bladder urgency; it’s very uncomfortable.

“If you talk to people with spinal cord injury or you look at the literature, what you learn is that recovery of urinary function is as important or more important to those individuals than walking,” he said.

As many as 12,000 people in the United States are affected by acute spinal cord injuries similar to those found in dachshunds, and while there is a movement within the drug industry to use therapies already approved by the FDA, Levine said there are classes of FDA-approved drugs that are very similar to GM6001 that are currently being used for different treatments but, with further study, might be applicable to human spinal cord injuries as well.

“The results of this study are really encouraging in terms of a way forward,” Levine said. “There’s a lot of additional information that needs to get uncovered, but this is a first and very intriguing step at looking at how we can help people and dogs that have these injuries.”

The study can be found at https://www.ncbi.nlm.nih.gov/pubmed/28520505.