Capsule Expression and Genotypic Differences among Staphylococcus aureus Isolates from Patients with Chronic or Acute Osteomyelitis
Capsule Expression and Genotypic Differences among Staphylococcus aureus Isolates from Patients with Chronic or Acute Osteomyelitis
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DOI：
10.1128/iai.01214-08
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发表时间：
2009-05-01
影响因子：
3.1
通讯作者：
Sordelli, Daniel O.
中科院分区：
文献类型：
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作者：
Lattar, Santiago M.;Tuchscherr, Lorena P. N.;Sordelli, Daniel O.
有充分的证据表明，金黄色葡萄球菌荚膜多糖（CP）促进毒力。然而，荚膜表达的丧失可能导致S。金黄色葡萄球菌在慢性感染宿主中的持久性。本研究旨在确定非包囊性链球菌的相对患病率。慢性和急性骨髓炎患者的金黄色葡萄球菌。只有76/118（64%）的S.来自骨髓炎患者的金黄色葡萄球菌分离株表达CP，而来自除骨关节感染外的感染患者的血培养物的所有50个分离株均表达CP（P = 0.0001）。非包囊性S.慢性骨髓炎患者的金黄色葡萄球菌阳性率（53%）高于急性骨髓炎患者（21%）（P = 0.0046）。S.从6名慢性骨髓炎患者中的5名的多个样本中获得的金黄色葡萄球菌分离株表现出表型（CP、α-溶血素、β-溶血素、粘液和小菌落变体表型的表达）和/或基因型（脉冲场凝胶电泳和SPA分型）差异。未包囊S.金黄色葡萄球菌从每个慢性骨髓炎患者的至少一个样本中回收。从两名急性骨髓炎患者中获得的14个分离株在每组内彼此无法区分，并且都产生CP 5。总之，我们证明了未包裹的S.金黄色葡萄球菌在慢性骨髓炎患者中比在急性骨髓炎患者中更常见，这表明CP表达的缺失可能对金黄色葡萄球菌有利。金黄色葡萄球菌在慢性感染。我们的研究结果对多个S。从个体患者分离的金黄色葡萄球菌使我们能够建议选择无包膜的S.金黄色葡萄球菌很可能在患者长期骨感染期间发生。
There is ample evidence that Staphylococcus aureus capsular polysaccharide (CP) promotes virulence. Loss of capsule expression, however, may lead to S. aureus persistence in a chronically infected host. This study was conducted to determine the relative prevalence of nonencapsulated S. aureus in patients with chronic and acute osteomyelitis. Only 76/118 (64%) S. aureus isolates from patients with osteomyelitis expressed CP, whereas all 50 isolates from blood cultures of patients with infections other than osteoarticular infections expressed CP (P = 0.0001). A significantly higher prevalence of nonencapsulated S. aureus was found in patients with chronic osteomyelitis (53%) than in those with acute osteomyelitis (21%) (P = 0.0046). S. aureus isolates obtained from multiple specimens from five of six patients with chronic osteomyelitis exhibited phenotypic (expression of CP, alpha-hemolysin, beta-hemolysin, slime, and the small-colony variant phenotype) and/or genotypic (pulsed-field gel electrophoresis and spa typing) differences. Nonencapsulated S. aureus was recovered from at least one specimen from each chronic osteomyelitis patient. Fourteen isolates obtained from two patients with acute osteomyelitis were indistinguishable from each other within each group, and all produced CP5. In conclusion, we demonstrated that nonencapsulated S. aureus is more frequently isolated from patients with chronic osteomyelitis than from those with acute osteomyelitis, suggesting that loss of CP expression may be advantageous to S. aureus during chronic infection. Our findings on multiple S. aureus isolates from individual patients allow us to suggest that selection of nonencapsulated S. aureus is likely to have occurred in the patient during long-term bone infection.