title: Adherence of Streptococcus pneumoniae to polystyrene plates, effect of serum on adhesion, and virulence in the gerbil otitis media model.
abstract: The adherence of 11 pneumococcal strains to polystyrene was studied and expressed as the number of colony-forming units (CFU) recovered per 10(6)CFU of initial inoculum. Three strains were considered as strong adherent (>100CFU/10(6)), three as medium adherent (10-100CFU/10(6)), and five as low adherent (<10CFU/10(6)). All serotype 3 strains were low adherent whilst serotypes 23F and 19F behaved as strong or medium adherent. The impact of gerbil sera on adherence of six selected pneumococcal strains (one strong adherent, one medium adherent, and four low adherents) to abiotic material was also studied under two experimental conditions. In the presence of sera, the adherence ability of the strong, medium, and one low adherent strains decreased significantly. On the other hand, the adherence significantly increased in all strains when sera were removed following preincubation of bacteria exposed to sera, although such increase was statistically significant for five of them. Finally, the ability of two (one strong adherent and one low adherent) strains to induce otitis media in gerbils was also evaluated; the strong adherent strain behaved significantly more virulent than the less adherent in terms of ear damage and animal weight loss.
authors.affiliation: Departments of Medical Microbiology and Antimicrobial Chemotherapy, Fundación Jiménez Díaz, 28040 Madrid, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Huelves
authors.forename: Gema
authors.initials: G
authors.lastname: del Prado
authors.forename: Violeta
authors.initials: V
authors.lastname: Rodriguez-Cerrato
authors.forename: Matilde
authors.initials: M
authors.lastname: Gracia
authors.forename: Carlos
authors.initials: C
authors.lastname: Cenjor
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Granizo
authors.forename: Carmen
authors.initials: C
authors.lastname: Ponte
authors.forename: Francisco
authors.initials: F
authors.lastname: Soriano
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000276:immunology* / Q000502:physiology*; D001835:Body Weight; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D004432:Ear, Middle / Q000382:microbiology / Q000473:pathology; D005849:Gerbillinae; D006801:Humans; D010033:Otitis Media / Q000276:immunology* / Q000382:microbiology*; D011137:Polystyrenes; D044967:Serum / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000472:pathogenicity* / Q000502:physiology*; D014774:Virulence
chemical_list: D011137:Polystyrenes