Bacterial speck in tomatoes is a pathogen with a knack for overcoming resistant varieties and pesticides.

But researchers with Virgnia Tech University's Virginia Bioinformatics Institute in Blacksburg, Virg., have sequenced several isolates of the pathogen to try to figure out how it overcomes plant defenses, according to a news release.

Their goal is to develop eventual ways to halt its spread.

The research team, led by plant pathologist Boris Vinatzer, spent five years comparing DNA sequences of Pseudomonas syringae pv. tomato from multiple years, dating as far back as 1960.

One of the questions they wanted to answer was whether the bacteria isolated from 2000 evolved from isolates from 1975, or did they evolve independently.

The result suggest that the pathogen likely evolved on a relatively recent time scale.

It continues to adapt by flying under a plant defense's radar screen, going undetected.

The next phase of the research will focus on from where the pathogen originated, how it is spreading globally what can be done to slow its spread.