Final answer:
Staphylococcus epidermidis is the species most frequently associated with nosocomial infections transmitted via medical devices inserted into the body, capable of causing systemic infections and resistant to many antibiotics.
Step-by-step explanation:
The species frequently associated with nosocomial infections transmitted via medical devices inserted into the body is Staphylococcus epidermidis. While it is often a harmless resident of the skin microbiota, S. epidermidis can cause serious infections when transferred to medical devices such as catheters, prostheses, and indwelling medical devices. These infections can become systemic if not quickly and properly treated, especially since S. epidermidis, similar to Staphylococcus aureus, is resistant to many antibiotics.