P47模拟多肽抗原在诊断侵袭性白色念珠菌感染中的应用

Application of P47 surrogate peptides in serological diagnosis of invasive infection of Candida albicans

目的利用噬菌体肽库来源的P47模拟抗原建立的ELISA法,探讨该模拟抗原在侵袭性白色念珠菌病血清学诊断中的应用价值。方法收集经培养确诊的各类念珠菌侵袭性感染和浅表感染的病人血清130份,用模拟抗原包被ELISA微孔板,测定抗P47抗体,考察该方法能否区分白色念珠菌侵袭性感染和浅表感染,以及与其他念珠菌感染的交叉反应。结果经细菌培养鉴定确证为白色念珠菌侵袭性感染的病人血清35份,抗P47抗体阳性率为100%,浅表感染者阳性率为4.8%(2/42),热带念珠菌侵袭性感染者抗P47抗体阳性率为16.7%(3/18)。光滑念珠菌、近平滑念珠菌以及未能鉴定到种的念珠菌侵袭性和浅表感染者血清,均未检测到抗P47抗体。结论用白色念珠菌菌丝蛋白P47模拟抗原建立ELISA检测抗P47抗体,虽然与热带念珠菌侵袭性感染有部分交叉反应,但仍可用于白色念珠菌侵袭性感染的血清学诊断。

Objective Using P47 surrogate peptides to develop an enzyme-linked immunosorbent assay （ELISA） for detection of C. albicans antibodies, and investigate its applicable value in serological diagnosis of invasive infection of C. albicans. Methods One hundred and thirty sera from patients with various Candida infections confirmed by microbiological culture were collected. The surrogate peptides selected by phage display were used as coating antigen to detect the antibodies against P47 in the sera of patients. The applicability of the method in distinguishing invasive infections from superficial infections of C. albicans was evaluated. The cross-reactivity with other Candida infection was also observed. Results Tile P47 antibody was detectable in all of 35 patients with invasive infection of C. albi- cans, 2 of 42 patients （4.8%） with superficial infection of C. albicans and 3 of 18 patients （ 16.7% ） with invasive infection of C. tropicalis. P47 antibody was negative in sera of the patients infected with C. glabrata, C. parapsilosis and unidentified Candida, no matter invasive or superficial. Conclusion The surrogate peptides can be used for ELISA in detecting the specific antibody of C. albicans although a weak cross reaction with C. tropicalwas shown.