Unencapsulated Streptococcus pneumoniae from conjunctivitis encode variant traits and belong to a distinct phylogenetic cluster.
Streptococcus pneumoniae, an inhabitant of the upper respiratory mucosa, causes respiratory and invasive infections as well as conjunctivitis. Strains that lack the capsule, a main virulence factor and the target of current vaccines, are often isolated from conjunctivitis cases. Here we perform a comparative genomic analysis of 271 strains of conjunctivitis-causing S. pneumoniae from 72 postal codes in the United States. We find that the vast majority of conjunctivitis strains are members of a distinct cluster of closely related unencapsulated strains. These strains possess divergent forms of pneumococcal virulence factors (such as CbpA and neuraminidases) that are not shared with other unencapsulated nasopharyngeal S. pneumoniae. They also possess putative adhesins that have not been described in encapsulated pneumococci. These findings suggest that the unencapsulated strains capable of causing conjunctivitis utilize a pathogenesis strategy substantially different from that described for S. pneumoniae at other infection sites.
1] Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, 243 Charles Street C703, Boston, Massachusetts 02114, USA [2] Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA [3] The Broad Institute of MIT and Harvard, 320 Charles Street, Cambridge, Massachusetts 02141, USA.
Michael D
MD
Valentino
The Broad Institute of MIT and Harvard, 320 Charles Street, Cambridge, Massachusetts 02141, USA.
Abigail Manson
AM
McGuire
Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Pl., Memphis, Tennessee 38105, USA.
Jason W
JW
Rosch
1] Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, 243 Charles Street C703, Boston, Massachusetts 02114, USA [2] Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA.
Paulo J M
PJ
Bispo
Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Pl., Memphis, Tennessee 38105, USA.
Corinna
C
Burnham
Bausch and Lomb Inc., 1400 Goodman Street North, Rochester, New York 14609, USA.
Christine M
CM
Sanfilippo
Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Pl., Memphis, Tennessee 38105, USA.
Robert A
RA
Carter
Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, 1 Rope Ferry Road, Hanover, New Hampshire 03755, USA.
Michael E
ME
Zegans
Streptococcus Laboratory, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, Georgia 30333, USA.
Bernard
B
Beall
The Broad Institute of MIT and Harvard, 320 Charles Street, Cambridge, Massachusetts 02141, USA.
Ashlee M
AM
Earl
Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Pl., Memphis, Tennessee 38105, USA.
Elaine I
EI
Tuomanen
Bausch and Lomb Inc., 1400 Goodman Street North, Rochester, New York 14609, USA.
Timothy W
TW
Morris
1] Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, 243 Charles Street C703, Boston, Massachusetts 02114, USA [2] Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA.
Wolfgang
W
Haas
1] Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, 243 Charles Street C703, Boston, Massachusetts 02114, USA [2] Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA [3] The Broad Institute of MIT and Harvard, 320 Charles Street, Cambridge, Massachusetts 02141, USA.
Michael S
MS
Gilmore
D018829:Adhesins, Bacterial / Q000235:genetics; D058345:Asymptomatic Infections; D016667:Bacterial Capsules / Q000235:genetics; D015153:Blotting, Western; D003234:Conjunctivitis, Bacterial / Q000453:epidemiology / Q000382:microbiology*; D016680:Genome, Bacterial / Q000235:genetics; D006801:Humans; D005810:Multigene Family / Q000235:genetics; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D058974:Phylogeography; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000472:pathogenicity; D014481:United States / Q000453:epidemiology; D037521:Virulence Factors / Q000235:genetics
D018829:Adhesins, Bacterial; D037521:Virulence Factors