Submitted to: Microbial Pathogenesis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2018
Publication Date: 3/26/2018
Citation: Schaut, R.G., Loving, C.L., Sharma, V.K. 2018. Escherichia coli O157:H7 virulence factors differentially impact cattle and bison macrophage killing capacity. Microbial Pathogenesis. 118:251-256. https://doi.org/10.1016/j.micpath.2018.03.045.
Interpretive Summary: Escherichia coli O157:H7 are bacteria that can come from many different animals. These bacteria can produce from a mild diarrheal illness to more severe type of disease leading to kidney failure and even death, especially in younger and older humans. Sometimes differences in the strains of E. coli O157:H7 can make disease worse in humans but not cause animals to become ill. Cattle are important as they are vital to our food supply and can pass along E. coli O157:H7 to humans directly or indirectly (through beef and milk). Another important animal are bison as they can also make humans sick from E. coli O157:H7. Differences between cattle and bison and their contact with E. coli O157:H7 is important for our understanding on how E. coli O157:H7 can make us sick. This study shows how cattle and bison cells react to strains of E. coli O157:H7 and will be helpful in understanding the mechanisms used by these animals to control the levels of these bacterial in their intestines
Technical Abstract: Enterohemorrhagic Escherichia coli O157:H7 frequently colonizes the gastrointestinal tract of ruminants, including cattle and bison, which are a reservoir of the zoonotic bacteria to humans. Healthy animals do not experience the clinical symptoms of disease that is induced by E. coli O157:H7 in humans; however, a variety of host immunological factors may play a role in the amount and frequency of fecal shedding. How gastrointestinal colonization by E. coli O157:H7 impacts these host animal immunological factors is unknown. Here, various isogenic mutant strains of a foodborne isolate of E. coli O157:H7 were used to evaluate macrophage killing responses of two ruminant species, cattle and bison. Cattle macrophages demonstrated an enhanced ability to phagocytose and kill E. coli O157:H7 compared to bison macrophages, and killing ability was impacted by E. coli 0157:H7 virulence gene expression. These findings suggest that the macrophage responses to E. coli O157:H7 might play a role in the variations observed in E. coli O157:H7 fecal shedding in ruminants in nature.