What type of bacteria can cause infections in a shaving nick?

Staphylococcus aureus is a type of bacteria commonly found on the skin and in the nasal passages of healthy individuals. It is particularly notable for its ability to cause infections when it enters the body through breaks in the skin, such as nicks that can occur during shaving. When the skin barrier is compromised, as is often the case with shaving, Staphylococcus aureus can invade tissues and lead to superficial skin infections, abscesses, or even more serious conditions like cellulitis or systemic infections if not properly managed.

Other types of bacteria listed can cause infections, but they do not have the same direct association with skin breaks caused by shaving. Escherichia coli is more associated with gastrointestinal infections. Streptococcus pyogenes is known for causing throat infections and skin conditions like impetigo but is less frequently implicated in shaving nicks. Salmonella typhi is primarily known for causing typhoid fever and isn’t typically related to the kinds of infections that can occur from minor skin injuries. Thus, Staphylococcus aureus stands out as the most relevant bacterium for this specific scenario.