U.S.-China Promulgation of research on diseases
Researchers in the U.S. and China are collaborating to find ways to reduce the spread of Lyme disease and other tick- and vector-borne diseases, which pose a threat to human health, livestock and agriculture.
UTSA associate professor of bacterial pathogenesis Janakiram Seshu serves as principal investigator for one of the teams participating in the program, which is funded by the United States Department of Agriculture Scientific Cooperation Exchange Program and the Ministry of Agriculture of the People’s Republic of China. The program encourages the ongoing exchange of information between researchers from both countries, fostered by alternating visits by teams from both countries.
Seshu led a team of three researchers to China in the summer of 2012. Also making the trip were Adalberto Pérez De León, lab director and research leader, and Andrew Li, research physiologist of the USDA Agricultural Research Service at Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, which conducts research into pests of medical and veterinary importance, such as biting flies and ticks. During the two-week trip, they visited several research institutions, including the Chinese Center for Disease Control and Prevention in Beijing.
“We had the opportunity to observe all of their laboratories and their facilities,” Seshu stated.
According to Seshu, the USDA has a facility right in Beijing composed of people from the U.S. who are responsible for surveillance and ensuring the containment of diseases.
“That is a major problem because of the global trade. We have to constantly think about what are the things that could come in and also be aware of some of the issues that they have there. If we don’t collaborate we don’t know much,” Seshu declared.
Fostering collaborative endeavours
According to Seshu, a concern about the safety of imports from China is one reason the USDA wanted to include researchers of tick-borne disease in the program.
“They have a lot of other diseases that we don’t have,” Seshu said. “So the question is what are the surveillance procedures and other ways to prevent any potential transfer of diseases from China into the U.S.?” he continued.
Pérez De León affirms that securing a healthy food source to feed a growing population is another motivation for the USDA to solve the problems posed by livestock pests.
“By 2050 at least 9 billion people will be on this planet and we are going to have to increase food production by 100 percent,” Pérez De León stated. “There is less and less arable land, less land to raise cattle,” Pérez De León continued.
According to Seshu, the program’s aim is to help stop the reach of diseases spread by vectors such as ticks and other animals. The collaboration also benefits China, which has seen an increase in cases of Lyme disease in the Tibetan region and concerns regarding the spread of African swine fever and other vector-borne diseases.
Seshu asserts that the collaboration’s biggest impact so far has been improving surveillance efforts to share information about potential disease outbreaks more efficiently.
“The most important thing we are doing now is we are enhancing our interactions with China in terms of surveillance measures so that if there is a major outbreak of something, we will know about it quickly,” Seshu stated.
Moreover, working with the USDA has expanded the nature of the research Seshu’s lab is conducting to include diseases affecting domestic animals and not just humans.
Seshu affirms that the collaborative grant enabled the success and expansion of the program, as well as research foci on the economic part of vectorborne infections and the agricultural consequences of vector-borne infections and also global trade related impact on our national security and health.
“It just completely changed our perspective, rather than just focusing on one disease and one pathogen, it enhanced our ways of looking at it from a perspective that is a lot more global and to other vector-borne infections in general.”
Seshu expresses his enjoyment of the educational opportunity and the overall experience.
“It wasn’t just me sharing our part of the story but we also learned a whole lot that we are implementing right now,” he said.
Seshu has several research projects related to Lyme disease—the most prevalent arthropod-borne disease in the U.S.—underway in his lab.
According to Seshu, the tick has been on Earth for around 300 to 400 million years and that evolutionarily, they have withstood a lot of changes on Earth.
Seshu’s research contribution involves unlocking the gene expression code that allows Borrelia burgdorferi, the bacteria that causes Lyme disease, to thrive in certain species of ticks and transfer to vertebrates. Researchers are trying to learn how the genes of the bacteria adapt to the significant changes in environment—such as temperature, immunities and pH—between ticks and the animals on which they feed.
“What we are trying to do is essentially look at a lot of the mechanisms by which this bacteria is able to survive in a tick,” Seshu stated. “What is happening to the bacteria that is enabling the bacteria to go from a tick vector to a vertebrate host?” he continued.
According to Seshu, a human vaccine for Lyme disease that used to be available is no longer manufactured. Most cases of Lyme disease are successfully treated with antibiotics. But in about 20-25 percent of cases, symptoms persist despite antibiotic treatment.
“One big problem with Lyme disease is once people get it, they can go to the doctor get some antibiotics and for the most part they get cured,” Seshu said. “But there is a proportion of people who continue to have this pathogen even after antibiotic treatment and they will go on to progressing to chronic arthritis or persistent manifestations of this disease,” Seshu continued.
The bacterial agent that causes Lyme disease belongs to a special class of bacteria known as spirochetes, which also cause syphilis and dental infection. In order to become infected with the disease causing bacteria, ticks must feed on infected animals such as mice, rabbits, deer or lizards. Not all tick species carry the disease.
According to the Centers for Disease Control, in 2011, 96 percent of Lyme disease cases were reported in 13 states including Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Vermont, Virginia and Wisconsin. By comparison, Seshu affirms that the likelihood of infected ticks in Texas is quite small.
“We have been looking at genes or regulators of gene expression that are allowing these bacteria to go from an environment in the tick to that of a vertebrate host,” Seshu said.
“If the ticks feed on you, the blood it takes is about 37 degrees Celsius. It has a lot of immune components and lot of other nutrients. How is it able to do it? We are focusing on two global gene regulators that are regulating a whole bunch of genes in the agent of Lyme disease that is allowing it to survive in the tick and also when the ticks take a blood meal it is able to change its gene expression to survive in the mammal,” Seshu continued.
Because ticks acquire the Lyme-causing bacteria from infected small mammals or lizards, researchers also are looking for ways to curb infection in those host animals, as well.
“We have two major questions: How is the bacteria able to adapt? And how are the bacteria able to go from the skin to the joint?” Seshu said. “How do you lock the bacteria in the tick midgut so that it is not able to come out?”
According to Edwin Barea-Rodriguez, Chair of the biology department, collaborations are essential in science research today.
“You have to think about the broad impact and the things we learn from each other,” Barea-Rodriguez stated. “Even if we are doing similar research their approach may be different,” Barea- Rodriguez continued.
Barea-Rodriguez affirms that international collaborations are especially important and are becoming easier to pursue.
“We (scientists) think, this is important and imperative that we do it. There may be barriers in communication, barriers in technology. I think the barriers are coming down. It’s becoming less difficult,” Barea-Rodriguez stated.
The program will bring a team of Chinese researchers to visit UTSA and the USDA ARS lab in Kerrville in the summer of 2015, which hosted two Chinese students in the spring and fall of 2012.
In a time of limited resources, finding ways to maximizing them is crucial, said Pérez De León, explaining that his team was interested in working with Seshu to pursue the grant enabling them to participate in the program.
“Science is so complex these days that there is no one who knows everything and can do everything,” Pérez De León declared.