Which organism is commonly associated with native valve endocarditis?

Which organism is commonly associated with native valve endocarditis?

• A. Staph aureus
• B. Enterococcus faecalis
• C. Strep viridans
• D. Staph epidermidis

Answer: (C)

Streptococcus viridans is classically linked to native valve endocarditis. These bacteria are part of the normal oral flora and can enter the bloodstream during dental procedures or even routine brushing. Once in circulation, they tend to adhere to and colonize previously damaged native heart valves, leading to a subacute, indolent infection rather than an abrupt, fulminant illness. This pattern—oral flora causing subacute endocarditis on a native valve—is why viridans streptococci are the classic answer in this context. The other organisms fit different scenarios: Staphylococcus aureus often causes acute endocarditis and can affect normal valves, Staphylococcus epidermidis is more typical of prosthetic valve or device-related infections, and Enterococcus faecalis is common in healthcare-associated cases or after GI/GU procedures, though it can involve native valves too.

Streptococcus viridans is classically linked to native valve endocarditis. These bacteria are part of the normal oral flora and can enter the bloodstream during dental procedures or even routine brushing. Once in circulation, they tend to adhere to and colonize previously damaged native heart valves, leading to a subacute, indolent infection rather than an abrupt, fulminant illness. This pattern—oral flora causing subacute endocarditis on a native valve—is why viridans streptococci are the classic answer in this context. The other organisms fit different scenarios: Staphylococcus aureus often causes acute endocarditis and can affect normal valves, Staphylococcus epidermidis is more typical of prosthetic valve or device-related infections, and Enterococcus faecalis is common in healthcare-associated cases or after GI/GU procedures, though it can involve native valves too.