UTSA professor investigates tick borne disease

Few organisms can make the person’s skincrawl more than the blood sucking arachnid known as a tick. While most peoplehave to worry about these tiny creatures only when caring for a dog or cat,ticks can cause a variety of problems ranging from the disruption of trade toLyme disease.

Dr. Janakiram Seshu, associate professor ofbacterial pathogens in the UTSA department of biology, has devoted time andenergy to learning about ticks and ways to prevent carrying of disease.According to Seshu, “This is a major problem for not only human infection butalso a number of diseases that affect domestic animals.”

This past June and July, Seshu and two otherresearchers from the United States Department of Agriculture in Kerrville, TXtravelled to China to conduct research on these small organisms and learn howto reduce the exchange of pathogens between the two countries.

The expedition was part of a collaborativeeffort between the U.S. Department of Agriculture and the Ministry ofAgriculture in China. The trip was funded by a proposal written through UTSAand the USDA facility in Kerrville. The grant awarded to Seshu and the otherscientists creates what is considereda scientific exchange program and allows investigators from the U.S. to visit anumber of different places in China.

China was a particular area of interest tothe study of tick-borne infectious diseases because of the high level ofinteraction between the U.S. and China. “The USDA is very particular aboutmaking sure we are not bringing in what are known as ticks or other insectvectors that carry disease into the U.S.,” says Seshu.

According to the Office of the United StatesTrade Representative, U.S. goods and services traded with China totaled $539billion in 2011- with $411 billion in imports alone. China is considered thelargest supplier of goods to the U.S. and the fifth largest supplier ofagricultural goods. This high level of interaction between the two countrieseasily facilitates the spread of infectious disease from one to the other.

Lyme disease has also been a major problem inboth China and the United States. It is the most common tick-borne infectionwith over 30,000 cases reported to the Center for Disease Control every year.“We are very interested in finding out the mechanisms by which we can reducethese infections and prevent this infection from happening,” claims Seshu.

While ticks are highly effectual in areasconcerning trade, the small insect can also have dangerous health implications.When bitten, bacteria are deposited onto the skin leaving a red legion. Fromthere the bacteria can spread to the joints and cause painful swelling. Inworst-case scenarios, the bacteria can spread to the heart or the brain. Themost common and painful manifestation of Lyme disease is swelling of the jointsand arthritis.

Antibiotics can clear the body of bacteria;however, the virus is almost never completely eliminated, even aftertreatments. Many of those infected will continue to have swelling in thejoints, giving the disease more chronic characteristics.

“Our main focus is, how do we stop thisbacteria from going from a tick to a host, which will be a human or otherdomesticated animals,” explains Seshu. “What we’re trying to see is, what arethe molecular organisms that allow this bacteria to go from a tick to a hostand what are the things we can do to stop it.”

The agent of Lyme disease is a spiralbacterium which is highly motile in its ability to spread. Ticks act as acarrier for the bacteria, transmitting the infection to various hosts. Seshuelaborated on his research efforts by explaining, “Our main goal is to eitherlock the transmission from the tick to the host, or prevent the transmissionfrom the host back to the tick.”

Once the bacteria in the tick population canbe reduced, infection in humans will decrease proportionally.

Tick bites are most common in heavilyforested regions and during the summer. While a majority of ticks can be foundin the northeast regions of the U.S. and around the Great Lakes, roughly 150cases were reported in Texas last year, predominately in the Houston area.

The U.S. Department of Agriculture takes akeen interest in reducing the number of cases because of the potential threatticks pose to cattle and sheep. Ranches in the South Texas region focus heavilyon eradicating ticks so that the financial loss of livestock is reduced.

“Basically it’s a big problem in the U.S.,”posits Seshu. “We had a vaccine that has been discontinued for a variety ofreasons, mostly economic. There is still a huge need to identify the ways toreduce this infection in humans.”

Seshu and his team studied how diseases andbacteria are spread through vectors, disease carrying agents. One of the mostbeneficial aspects of the study is that principles discovered by researcherscan be applied to other bacteria transmitted by vectors.

One such prevalent vector is the mosquitothat can transmit malaria and West Nile virus.According to the World Health Organization, in 2010 malaria infected and killedan estimated 660,000 people and, in cities as close as Dallas, huge outbreaksof West Nile virus have been reported. Discoveries made using the tick modelfor Lyme disease will be copied to limit these diseases.

“By enhancing our collaborative efforts, weare trying to make sure animals and plants can be identified as infected andnot allowed to come into the U.S.,” explains Seshu of the close scientificrelations between the U.S. and China.

In their travels to China, Seshu and his teamhoped to increase the methods of pathogen detection in different vectors commonto domestic Chinese animals. While not all goods produced in China are exportedto the U.S., Seshu and his team believe vector research is important inreducing the diseases responsible for significant agricultural loss.

“It’s a mutual benefit. When those diseasesin China are eliminated, you can be sure products coming out of those parts ofChina are free of disease,” says Seshu.

Seshu believes the economic rationale forcollaborating with China is high, because future threats to the U.S. in areasof health and agriculture can be reduced.

Plans to collaborate research efforts willcontinue between the U.S. Department of Agriculture and China. Seshu believesconnections established between the two countries are invaluable with potentialfor long-term benefit.

“From a UTSA perspective, students will have anopportunity to interact with centers from China. Most importantly, there is greaterrecognition of our research efforts as a university.”