Final answer:
Bacterial endocarditis is most commonly caused by Staphylococcus aureus, viridans streptococci, and Enterococcus faecalis, which are gram-positive cocci bacteria. HACEK bacilli, including Haemophilus spp., Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae, can also cause bacterial endocarditis.
Step-by-step explanation:
Bacterial endocarditis is most commonly caused by several pathogens, including Staphylococcus aureus, viridans streptococci, and Enterococcus faecalis. These are gram-positive cocci bacteria. Additionally, the gram-negative HACEK bacilli, which include Haemophilus spp., Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae can also cause bacterial endocarditis.