Microbicidal Activity of Hypothiocyanite against Pneumococcus

Infections caused by Streptococcus pneumoniae (pneumococcus, Spn) manifest in several forms such as pneumonia, meningitis, sinusitis or otitis media and are associated with severe morbidity and mortality worldwide. While current vaccines and antibiotics are available to treat Spn infections, the rise of antibiotic resistance and limitations of the vaccines to only certain Spn serotypes urge the development of novel treatments against Spn. Hypothiocyanite (OSCN-) is a natural antimicrobial product produced by the body’s own innate immune system to fight a variety of pathogens. We recently showed that OSCN- is also capable of killing Spn in vitro. OSCN- is an oxidative agent attacking microbes in a nonspecific manner, is safe for the host and also has anti-inflammatory effects that make it an ideal candidate to treat a variety of infections in humans. However, OSCN- has a short life span that makes its use, dosage and administration more problematic. This minireview discusses the antimicrobial mechanism of action of OSCN- against Spn and elaborates on the potential therapeutic use of OSCN- against Spn and other infectious agents, either alone or in combination with other therapeutic approaches.