Diagnostic value of Streptococcus pneumoniae autolysin rLytA for community acquired pneumonia
10.3760/cma.j.issn.1009-9158.2017.03.015
- VernacularTitle:肺炎链球菌自溶素蛋白LytA对社区获得性肺炎的血清学诊断意义
- Author:
Jie ZHOU
;
Hong LUO
;
Guang YANG
;
Wenping SUN
- Keywords:
Streptococcus pneumoniae;
Pneumonia;
Community-acquired infections;
N-acetylmuramoyl-L-alanine amidase;
Serologic tests;
Enzyme-linked immunosorbent assay
- From:
Chinese Journal of Laboratory Medicine
2017;40(3):217-220
- CountryChina
- Language:Chinese
-
Abstract:
Objective To obtain the recombinant protein LytA (rLytA) of Streptococcus pneumoniae strain (ATCC49619) through prokaryotic expression system and to investigate their diagnostic value for patients with community acquired pneumonia (CAP).Methods The specific primers were designed according to LytA gene sequence of Streptococcus pneumoniae M66 strain recorded in Genbank.The recombinant plasmid pET32a(+)/LytA was constructed and transformed into BL21(DE3) to express LytA.The expressed protein LytA was purified by electroeluting of bag filter.Serum IgM of anti-LytA accordingly of patients with CAP were detected by ELISA.The results were evaluated by Chi-square test.Results The recombinant protein LytA was expressed and purified successfully with a relative molecular weight of 56 000.The IgM antibodies level of anti-LytA was significantly higher than the healthy control group (P=0.000).Diagnostic sensibility and specificity of LytA-IgM were 27.8% and 100.0%,while sensibility and specificity of sputum culture were 19.4% and 72.2%,respectively.The sensibility of LytA-IgM was equal to sputum culture(χ2=0.693,P=0.405),but the specificity was higher than it(χ2=14.316 P=0.000).Conclusions A rLytA-ELISA assay maybe has clinical value for diagnosis of pneumococcal infections.It is more rapid and objective than the culture method.
