title: Protective effect of heterologous gram-positive vaccine against lethal upper respiratory tract infection with type M50 group A streptococci in mice.
abstract: Type M50 group A streptococci are exceptional for their virulence in mice. However, intranasal (i.n.) vaccination with heat-killed group A streptococci, either of type M50 or M55, or an M12 strain deficient in M-protein, protected mice against i.n. challenge with M50 streptococci (82, 88 and 83% survival, respectively). Significant resistance against M50 streptococci was also noted by i.n. application of heat-killed Lactobacillus fermenti (81% survival) as well as two strains of pneumococci (50 and 79% survival). In contrast, no protective effect was obtained using heat-killed trypsin-treated M55 streptococci. Nor did vaccination with Escherichia coli and Pseudomonas aeruginosa induce protection against type M50. Thus, M protein was not required for immunity against type M50. The results call for a revision of the hitherto accepted view that M proteins are the only candidates for mucosal vaccines against group A streptococci.
authors.affiliation: Department of Oto-Rhino-Laryngology, University Hospital, Lund, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Stjernquist-Desatnik
authors.forename: D N
authors.initials: DN
authors.lastname: Kurl
authors.forename: C
authors.initials: C
authors.lastname: Schalén
authors.forename: P
authors.initials: P
authors.lastname: Christensen
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology; D005260:Female; D006094:Gram-Positive Bacteria / Q000276:immunology*; D007778:Lactobacillus / Q000276:immunology; D051379:Mice; D011550:Pseudomonas aeruginosa / Q000276:immunology; D012141:Respiratory Tract Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D013297:Streptococcus pyogenes / Q000276:immunology / Q000472:pathogenicity
chemical_list: D001428:Bacterial Vaccines