Final answer:
NSTIs typically include a mixture of pathogenic bacteria but can also involve molds and nitrifying bacteria, with Nostoc being one of the smallest multicellular organisms capable of photosynthesis and nitrogen fixation.
Step-by-step explanation:
Necrotizing Soft Tissue Infections (NSTIs) involve a broad spectrum of bacteria and fungi. Common organisms seen in these infections are molds, which are ubiquitous fungi, and nitrifying bacteria, which are a group of organisms that include both autotrophs and heterotrophs. Among the smallest multicellular organisms that can be found are Nostoc, which are part of the cyanobacteria group.
These cyanobacteria are capable of both photosynthesis and nitrogen fixation, making them very independent organisms. In NSTIs, however, the organisms are primarily pathogenic bacteria and often involve a mix of aerobic and anaerobic bacteria.