Vitamin A-Deficient Hosts Become Nonsymptomatic Reservoirs of Escherichia coli-Like Enteric Infections
Vitamin A deficiency (A−) remains a public health concern in developing countries and is associated with increased susceptibility to infection.Citrobacter rodentiumwas used to model humanEscherichia coliinfections. A−mice developed a severe and lethal (40%) infection. Vitamin A-sufficient (A+) mice survived and cleared the infection by day 25. Retinoic acid treatment of A−mice at the peak of the infection eliminatedC. rodentiumwithin 16 days. Inflammation levels were not different between A+and A−mouse colons, although the A−mice were still infected at day 37. Increased mortality of A−mice was not due to systemic cytokine production, an inability to clear systemicC. rodentium, or increased pathogenicity. Instead, A−mice developed a severe gut infection with most of the A−mice surviving and resolving inflammation but not eliminating the infection. Improvements in vitamin A status might decrease susceptibility to enteric pathogens and prevent potential carriers from spreading infection to susceptible populations.