In vitro bactericidal activity of Streptococcus pneumoniae and bactericidal susceptibility of Staphylococcus aureus strains isolated from cocolonized versus noncocolonized children.
Streptococcus pneumoniae is bactericidal to Staphylococcus aureus in vitro. To determine whether this in vitro effect accounts for the inverse relation between S. pneumoniae and S. aureus colonization reported in previous epidemiologic studies, we compared S. pneumoniae and S. aureus strains from cocolonized children to those from noncocolonized children. Cocolonizing pneumococci were less bactericidal and cocolonizing staphylococci less susceptible to this effect; however, the magnitude of the effect was small. Thus, in vitro killing is not the major determinant of the pattern of cocolonization.
Department of Epidemiology and Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA. gregev@hsph.harvard.edu
Gili
G
Regev-Yochay
Richard
R
Malley
Ethan
E
Rubinstein
Meir
M
Raz
Ron
R
Dagan
Marc
M
Lipsitch
D000898:Antibiosis; D002353:Carrier State / Q000382:microbiology*; D002648:Child; D015169:Colony Count, Microbial; D006801:Humans; D050296:Microbial Viability; D011008:Pneumococcal Infections / Q000382:microbiology; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification* / Q000502:physiology*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification* / Q000378:metabolism*