Norepinephrine Can Boost Campylobacter Virulence
Study measures effects of norepinephrine on C. jejuni in a model system
WEDNESDAY, Aug. 15 (HealthDay News) -- When Campylobacter jejuni is grown in iron-limited media in the presence of norepinephrine, virulence-associated properties are increased compared to cultures grown in the absence of norepinephrine, according to a report in the August issue of Gut. The findings suggest that stress may affect the pathogenicity of the bacteria in food animals or humans, according to an editorial.
Tristan Cogan, Ph.D., of the University of Bristol, U.K., and colleagues cultured C. jejuni originally isolated from human infection. The cultures were grown in iron-limited and iron-replete media in the presence and absence of norepinephrine. Virulence-associated characteristics were measured and compared.
The cultures in iron-restricted media exposed to norepinephrine had an increased growth rate, a greater number of motile cells, and increased invasion of cultured epithelial cells as compared to cultures not exposed to norepinephrine. Bacteria exposed to norepinephrine caused greater disruption of monolayers with widespread breakdown of tight junctions in cultured epithelial cells.
"As most C. jejuni infections in man in the western world are sporadic in nature, are we more susceptible to these organisms in stressful times?" writes the author of an accompanying editorial. "The production of stress-free 'happy' animals for food may have implications for preventing the acquisition and potential transmission of disease adapted C. jejuni."