Montanaro L, Arciola C R, Baldassarri L, Borsetti E
Laboratorio di Biocompatibilità dei Materiali da Impianto, Istituti Ortopedici Rizzoli, Bologna, Italy.
Biomaterials. 1999 Oct;20(20):1945-9. doi: 10.1016/s0142-9612(99)00099-x.
Prosthesis-associated infections still represent one of the most serious complications in the clinical use of biomaterials. The most frequent causes are Staphylococcus aureus and Staphylococcus epidermidis. Several studies have been devoted to identify adhesion mechanisms for these bacteria. Slime in particular has been extensively investigated. Recently, in Staphylococcus aureus species, considerable attention has been given to the host protein receptors that have been shown in in vitro assays to serve as substrates for bacterial adhesion. Collagen-rich tissues, as bone and cartilage, that are the preferential sites of staphylococcal infections, are also the tissues that harbour orthopaedic implants. These can be easily coated in vivo by collagen and thus become prone to adhesion of Staphylococci strains which carry the collagen adhesin gene (cna). In this study the frequency of cna was determined within a collection of 35 Staphylococcus aureus strains from orthopaedic prosthesis infections by a PCR method. Also the collagen-binding ability and slime forming capacity was evaluated. 29% of the strains were cna-positive and also able to bind collagen in vitro. 83% of the strains were slime forming. The results indicate that in the examined bacterial population slime-positive strains predominate over the cna-positive strains, with a striking association of the two adhesion mechanisms in cna-positive strains.
假体相关感染仍然是生物材料临床应用中最严重的并发症之一。最常见的病因是金黄色葡萄球菌和表皮葡萄球菌。已有多项研究致力于确定这些细菌的黏附机制。特别是黏液已得到广泛研究。最近，在金黄色葡萄球菌中，宿主蛋白受体受到了相当多的关注，体外试验表明这些受体可作为细菌黏附的底物。富含胶原蛋白的组织，如骨骼和软骨，是葡萄球菌感染的优先部位，也是植入骨科植入物的组织。这些植入物在体内很容易被胶原蛋白包被，因此容易黏附携带胶原蛋白黏附素基因（cna）的葡萄球菌菌株。在本研究中，通过PCR方法测定了从骨科假体感染中分离出的35株金黄色葡萄球菌中cna的频率。同时评估了胶原蛋白结合能力和黏液形成能力。29%的菌株cna呈阳性，并且在体外能够结合胶原蛋白。83%的菌株能够形成黏液。结果表明，在所检测的细菌群体中，黏液阳性菌株多于cna阳性菌株，且在cna阳性菌株中这两种黏附机制存在显著关联。
