DNA Scientists have developed a new way to track the activity of a microbe and the response of its intended host cell.

Chlamydia trachomatis bacterium causes the most common sexually transmitted disease in the United States and is a leading cause of blindness globally. Chlamydia infection causes a great deal of scarring that can cause affected organs to function poorly. Scarring from Chlamydia in the fallopian tubes causes infertility, for example, while scarring from Chlamydia in the eye causes the eyelash line to turn inwards and rub against the eye, damaging the protective corneal layer severely enough to cause eventual blindness.

While the bacteria Chlamydia is quite invasive, the body’s response to the infection – scarring – contributes to complications like infertility and blindness. The scientists in this recent study wanted to take a closer look at the earliest interactions between the invading pathogen and their host cells, as events in these early stages can affect the development of disease months or years later. In this case, early exposure to Chlamydia may result in scarring later.

Author of the study Garry Myers, Ph.D., from University of Maryland School of Medicine, likens infection to a series of falling dominoes where the body’s initial reaction to the presence of a pathogen can change the outcome. The body responds to the presence of the Chlamydia bacteria by activating genes responsible for creating scar tissue. The genes of some individuals tell their bodies to create a positive feedback loop, where the presence of scar tissue causes the body to create even more scar tissue that eventually interferes with organ function.

A gene is a segment of DNA, sometimes called “the blueprint of life” because it carries instructions on how cells are to act. When your DNA wants a cell to act in a certain way, it transcribes those instructions onto RNA cells, known as transcripts. Each cell keeps a copy of all the transcripts it has received; this copy is referred to as a transcriptome. Scientists use RNA-Sequencing techniques to look at these transcriptomes to learn more about them.

In this newest study, scientists developed a way to use RNA-Sequencing to look at transcriptomes from the Chlamydia bacteria and the host cell simultaneously. This new technique gives researchers new insight into how bacteria and cell genes express themselves in the earliest stages of infection.

Source: Humphrys, Michael S. "Simultaneous Transcriptional Profiling of Bacteria and Their Host Cells." PLOS ONE:. N.p., 4 Dec. 2013. Web. 21 Dec. 2013.