Nashev Dimitar, Toshkova Katia, Salasia S Isrina O, Hassan Abdulwahed A, Lämmler Christoph, Zschöck Michael
National Center of Infectious and Parasitic Diseases, 26 Y. Sakazov Blvd, 1504 Sofia, Bulgaria.
FEMS Microbiol Lett. 2004 Apr 1;233(1):45-52. doi: 10.1016/j.femsle.2004.01.032.
In the present study, we report data on virulence determinants of Staphylococcus aureus from stable nasal carriers, emphasizing on the genes encoding fibronectin (fnbA, fnbB) and collagen (cna) adhesive molecules. Of the 44 S. aureus isolates included, 32 isolates (16 pairs) were cultured from the anterior nares of 16 healthy carriers, eight isolates (four pairs) were collected from the nose of four patients with recurrent skin infections and four isolates were obtained from the infection site of these patients. The period between the two nasal swabs taken was 3-5 days. The persistency of carriage could be demonstrated by the indistinguishable genotypic characteristics of the S. aureus isolates in each pair. This could be shown by determination of gene polymorphisms of coa gene and the X-region and IgG-binding region encoding segments of spa gene. In addition, the isolates within the pairs showed identical toxin patterns. This was determined by PCR amplification of the genes encoding staphylococcal enterotoxins (SEA to SEJ) and TSST-1. The genotypic properties also yielded an identity between persistent nasal carriage isolates and the corresponding skin infection isolates of the four patients. In addition, all S. aureus nasal and skin infection isolates were positive for gene fnbA, fnbB and cna could be found with a high frequency. Among the 44 isolates investigated, 16 isolates (36.7%) harbored gene fnbB and 21 isolates (47.7%) gene cna. The data in the present study showed a relatively wide distribution of the genes fnb and cna among the investigated isolates, indicating that the persistent carriage of strains harboring these virulence determinants may increase the risk for subsequent invasive infections in carriers.
在本研究中，我们报告了来自鼻腔稳定携带者的金黄色葡萄球菌毒力决定因素的数据，重点关注编码纤连蛋白（fnbA、fnbB）和胶原蛋白（cna）黏附分子的基因。在所纳入的44株金黄色葡萄球菌分离株中，32株（16对）从16名健康携带者的前鼻孔培养获得，8株（4对）从4例复发性皮肤感染患者的鼻腔采集，4株从这些患者的感染部位获得。两次鼻拭子采集的间隔时间为3至5天。每对金黄色葡萄球菌分离株基因型特征无差异，可证明携带的持续性。这可通过测定coa基因以及spa基因编码X区域和IgG结合区域片段的基因多态性来显示。此外，每对中的分离株显示出相同的毒素模式。这通过对编码葡萄球菌肠毒素（SEA至SEJ）和TSST-1的基因进行PCR扩增来确定。基因型特性还显示持续性鼻腔携带分离株与4例患者相应的皮肤感染分离株具有一致性。此外，所有金黄色葡萄球菌鼻腔和皮肤感染分离株的fnbA、fnbB和cna基因均为阳性，且频率较高。在所研究的44株分离株中，16株（36.7%）携带fnbB基因，21株（47.7%）携带cna基因。本研究数据表明，fnb和cna基因在所研究的分离株中分布相对广泛，这表明携带这些毒力决定因素的菌株持续携带可能会增加携带者随后发生侵袭性感染的风险。
