TABLE 1.

Review of data from seven studies examining the causative agents of infective endocarditis in humans

Organism	Microorganisms identified by blood culture (%) in various studiesa
	Yuan (39), n = 167	Murdoch et al. (2), n = 2,781	Farag et al. (40), n = 360	Munoz et al. (41), n = 1,804	Xu et al. (42), n = 105	Selton-Suty et al. (43), n = 497	Yombi et al. (44), n = 212
S. aureus	44.3	31.0	24.7	40.3	10.4	26.6	23.6
S. epidermidis	1.8		6.4				6.1
S. lugdunensis	1.8		1.4				0.9
Other CoNSb	3.0	11.0	4.6	16.7*	12.4*	9.7*	5.3
Streptococcus viridansc	6.6	17.0	38.6	12.3	58.1		16.0
S. agalactiae	3.0		1.4				2.4
S. pyogenes							0.9
S. pneumoniae			0.6
S. gallolyticus		6	6.1	6.4		12.5	7.1
“Oral” streptococcid						18.7
Streptococcus group G							1.4
Enterococcus faecalis	6.6		11.1		4.8		11.8
Enterococcus spp.e				12.7

^aReferences for each study are indicated (n, number of patients in each study). A set of references were chosen based on a literature review of PubMed performed in 2018 focusing on the most common causes of IE that provided an overall prevalence of each pathogen that was encountered. The findings are consistent with the general understanding of pathogens associated with IE (3, 4, 38). *, studies that grouped all CoNS species together.

^bSome studies here distinguish S. epidermidis and S. lugdunensis from other more infrequent CoNS organisms associated with IE, including S. capitis, S. warneri, and S. haemolyticus (25, 40, 45).

^cThe viridans group streptococci causing IE include S. mitis, S. sanguinis, S. mutans, S. salivarius, S. gordonii, S. intermedius, and S. anginosus (28, 46–48).

^dViridans streptococci are referred to as oral streptococci in the indicated study.

^eSpecies not provided; however, E. faecalis causes ∼97% of IE cases associated with enterococci (3).