title: Evaluation of four experimental osteomyelitis infection models by using precolonized implants and bacterial suspensions.
abstract: Staphylococcus aureus osteomyelitis, a major problem in orthopedic surgery, often involves biofilm bacteria adhering to implants and surrounding bone and tissues. The inadequacy of therapy or immunological surveillance has encouraged studies using animal models which simulate natural osteomyelitic infections, ensure the development of infections and avoid mortality. We evaluated 4 models for infection (8 animals/model) in rats, using stainless-steel implants in tibiae and a very adherent slime-producing bacterial strain. Each animal received: an implant containing a 12 h-biofilm with about 10(6) cfu (Model 1); an implant containing this biofilm and a suspension with about 10(4) cfu (Model 2): a sterile implant and a suspension with about 10(5) cfu (Model 3); or a sterile implant and a suspension with about 10(6) cfu (Model 4). 63 days after surgery we found 100% rat survival, colonization of bone by implant biofilm bacteria in some animals and local, but not systemic infections. Model 1 (but not Models 2-4) reproduced an infection in both, tibiae and implants, most reliably (in 100% of the animals). Model 3 was the least reliable (p < 0.01, 25% infected implants, 12% infected tibiae).
authors.affiliation: CSIC-SIA, Department of Animal Health (DGA), Zaragoza, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Monzón
authors.forename: Felicito
authors.initials: F
authors.lastname: García-Alvarez
authors.forename: Antonio
authors.initials: A
authors.lastname: Laclériga
authors.forename: Beatriz
authors.initials: B
authors.lastname: Amorena
mesh_terms: D000818:Animals; D018441:Biofilms; D016009:Chi-Square Distribution; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D008297:Male; D008854:Microscopy, Electron; D016252:Microscopy, Scanning Tunneling; D010019:Osteomyelitis / Q000382:microbiology*; D011336:Probability; D019736:Prostheses and Implants / Q000382:microbiology*; D051381:Rats; D017208:Rats, Wistar; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013203:Staphylococcal Infections / Q000175:diagnosis*; D013211:Staphylococcus aureus; D013977:Tibia / Q000601:surgery / Q000648:ultrastructure