title: Nonencapsulated Streptococcus pneumoniae causes otitis media during single-species infection and during polymicrobial infection with nontypeable Haemophilus influenzae.
abstract: Streptococcus pneumoniae strains lacking capsular polysaccharide have been increasingly reported in carriage and disease contexts. Since most cases of otitis media involve more than one bacterial species, we aimed to determine the capacity of a nonencapsulated S. pneumoniae clinical isolate to induce disease in the context of a single-species infection and as a polymicrobial infection with nontypeable Haemophilus influenzae. Using the chinchilla model of otitis media, we found that nonencapsulated S. pneumoniae colonizes the nasopharynx following intranasal inoculation, but does not readily ascend into the middle ear. However, when we inoculated nonencapsulated S. pneumoniae directly into the middle ear, the bacteria persisted for two weeks post-inoculation and induced symptoms consistent with chronic otitis media. During coinfection with nontypeable H. influenzae, both species persisted for one week and induced polymicrobial otitis media. We also observed that nontypeable H. influenzae conferred passive protection from killing by amoxicillin upon S. pneumoniae from within polymicrobial biofilms in vitro. Therefore, based on these results, we conclude that nonencapsulated pneumococci are a potential causative agent of chronic/recurrent otitis media, and can also cause mutualistic infection with other opportunists, which could complicate treatment outcomes.
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA.
authors.forename: Kyle A
authors.initials: KA
authors.lastname: Murrah
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Pang
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Richardson
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA.
authors.forename: Antonia
authors.initials: A
authors.lastname: Perez
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Reimche
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA.
authors.forename: Lauren
authors.initials: L
authors.lastname: King
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA.
authors.forename: John
authors.initials: J
authors.lastname: Wren
authors.affiliation: Department of Microbiology and Immunology, Wake Forest School of Medicine, 2E-034 Wake Forest Biotech Place, 575 North Patterson Avenue, Winston-Salem, NC 27101, USA wswords@wakehealth.edu.
authors.forename: W Edward
authors.initials: WE
authors.lastname: Swords
mesh_terms: D000818:Animals; D002648:Child; D002682:Chinchilla; D002908:Chronic Disease; D060085:Coinfection / Q000382:microbiology* / Q000473:pathology; D004195:Disease Models, Animal; D006192:Haemophilus Infections / Q000382:microbiology* / Q000473:pathology; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D006801:Humans; D010033:Otitis Media / Q000382:microbiology* / Q000473:pathology; D013290:Streptococcal Infections / Q000382:microbiology* / Q000473:pathology; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
keywords: Haemophilus; coinfection; nonencapsulated; pneumococcus