An E.coli O157:H7 colony
An E.coli O157:H7 colony

What was once thought to be one potentially deadly strain of E. coli has grown to seven.

In addition to the better-known E. coli O157:H7, the group includes E. coli O26, O45, O111, O121, O130 and O145, according to a Alabama Cooperative Extension news release.

Officials with the Centers for Disease Control and Prevention estimate that as much as one-third of infections are caused by these newcomers.

As a result, state and federal health officials are recommending these be tested for because they most likely caused many foodborne outbreaks that until recently were blamed on E. coli O157:H7, according to a news release.

All of them can cause bloody diarrhea that can lead to kidney failure. In severe cases, they can cause death.

These strains are known scientifically as Shiga toxin-producing E. coli because they have the traits of one or both Shiga toxins.

Although some outbreaks of these nasty strains have been linked to fruits and vegetables, they are nearly always traced to warm-blooded animals, including birds, that have passed over or through farms.