Differential Effect of Parenteral Zinc on the Course of Various Bacterial Infections 1

Abstract

Summary

Intraperitoneal pretreatment of rats with zinc, as zinc chloride, 1 hr prior to bacterial challenge with S. typhimurium, F. tularensis, or S. pneumoniae enhanced mortality incidence in S. typhimurium infection only. Unlike previous reports concerning lead and cadmium, zinc's potentiation of lethality in an endotoxin-producing gram-negative infection does not appear to be attributable to heavy metal-induced increases in sensitivity to the toxic aspects of endotoxin. In contrast to the results obtained with S. typhimurium, single and multiple zinc treatments enhanced survival incidence during the early postinfection period in rats infected with F. tularensis or S. pneumoniae. These diverse observations can possibly be explained, in part, by zinc's ability to modify certain aspects of the host's defense mechanism such as leukocytosis, phagocytosis, and cell-mediated immunity as well as by zinc's inhibition of bacterial proliferation.