Nitric Oxide

In studying the many effects of NO, I came across this. I advocate eating less animal protein when sick and this may be the reason why. Thiols, or sulfur analogues, are in high concentration in animal protein. They also contribute to antimicrobial resistance by decreasing the antimicrobial action of NO.

Mechanisms of microbial resistance to reactive nitrogen intermediates have been incompletely characterized, but appear to overlap considerably with antioxidant defenses (Fig. 2B). Low molecular weight thiols have an important scavenging role in microbes, as they do in mammalian cells. Mutant Salmonella strains unable to synthesize glutathione (GSH) are hypersusceptible to inhibition S-nitrosothiols, peroxynitrite, and even NO• itself, suggesting that the high intracellular thiol concentrations of enteric bacteria may explain the lack of antimicrobial activity normally exerted by NO• against these pathogens. In contrast, Staphylococci contain low concentrations of GSH(61), and appear to be susceptible to NO• (40). Although mycobacteria and other actinomycetales do not synthesize GSH, they contain an alternative low molecular weight compound called mycothiol (61); trypanosomes and Leishmania sp. produce an analogous thiol called trypanothione (62). It remains to be determined whether these compounds can mediate analogous resistance to nitrosative and oxidative stress. The molecular interactions of S-nitrosoglutathione and glutathione have been characterized in detail recently (63), and similar transformations might occur within microbial cells. A complex set of reactions, dependent upon both relative glutathione concentration and the presence of oxygen, produces a mixture of products including oxidized thiol, ammonia, and nitrite (63).

Everything I find seems to back my observations.