Phenotypic modification of the reactivity in human serum of Escherichia coli K1 isolates.
Three Escherichia coli strains producing the K1 antigen and shown to be resistant to the complement-mediated bactericidal action of human serum when grown in batch culture, were cultivated in the chemostat under conditions of carbon-, nitrogen-, magnesium- and phosphate-limitation. All strains were fully serum resistant when grown under carbon-limiting conditions but became phenotypically serum sensitive when limited by magnesium. One strain, belonging to serogroup O7:K1, also displayed serum sensitivity when nitrogen limited and showed an intermediate serum response when phosphate was used as the limiting nutrient.
PubMed Abstracts
PubMed Abstracts