Mycoplasma pneumoniae antigen and application thereof in simultaneous quantitative detection of Mycoplasma pneumoniae IgG and IgM content in peripheral blood

Abstract

The invention discloses a Mycoplasma pneumoniae antigen and its application in simultaneous quantitative detection of Mycoplasma pneumoniae IgG and IgM content in peripheral blood. The amino acid sequence of the mutant Mycoplasma pneumoniae antigen P80 of the invention is as shown in SEQ ID NO.1. The immunoreactivity of the Mycoplasma pneumoniae antigen p80 and the antibody is about 34.6% higher than that of the natural antigen. By combining the Mycoplasma pneumoniae antigen P80 with the quantum dot immunochromatography technology, the shortcoming that existing detection methods of Mycoplasmapneumoniae antibody, such as immunochromatography assay (ICA) and enzyme-linked immunosorbent assay (ELISA), can only detect qualitatively or semi-quantitatively, and the MP-IgM and MP-IgG detection must be carried out twice is solved; and the detection of MP-IgM and MP-IgG can be realized at the same time, so as to distinguish the patients with recent infection or previous infection and reduce the misdiagnosis rate.

Description

technical field [0001] The invention belongs to the technical field of molecular biology and biological detection. Specifically, the invention relates to the development of a mycoplasma pneumoniae mutant and a fingertip blood sampling method to detect mycoplasma pneumoniae quantum dot immunochromatography kit. Background technique [0002] Mycoplasma pneumoniae (Mycoplasma Pneumoniae, Mp) is one of the most important pathogens causing community acquired pneumonia (Community Acquired Pneumonia, CAP). It is an ultrafilterable pathogenic microorganism between bacteria and viruses. According to reports, pneumonia caused by Mp infection accounts for 10-40% of CAP, and the incidence trend is still on the rise in recent years. Clinically, Mp infection mainly manifests as symptoms of bronchitis and upper respiratory tract infection. Its main features are slow onset, headache, fever, sore throat and discomfort, and the most typical dry cough and other symptoms. [0003] Usually, the...

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Problems solved by technology

However, considering its specificity, it is prone to false positives

Although real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) has high sensitivity and specificity, it has high nutritional requirements and takes a long time. The judgment of some results takes nearly one month. For the early diagnosis of Mp has produced certain obstacles

However, when the colloidal gold method is used to diagnose Mycoplasma pneumoniae, a large amount of reagent samples and a large amount of blood collection are used.

Although the detection of Mycoplasma pneumoniae antigen or NAT can be used for early diagnosis of infection, due to sample contamination or non-pathogenic bacterial colonization, the diagnostic false positive rate is high and the cost is expensive

Although the culture of Mycoplasma pneumoniae is considered as the gold standard for the diagnosis of MP, it has obvious methodological limitations, such as long culture time and low sensitivity.

The detection of Mycoplasma pneumoniae antibody can distinguish between colonized bacteria and pathogenic bacteria, but the markers used to detect antibodies at home and abroad are mostly conventional markers such as fluorescein isothiocyanate (FITC), which have a short fluorescence lifetime, are easy to quench, and emit light. Instability, small Stokes shift, and monochromatic excitation of a single light source are the limitations of FITC. Therefore, the positive rate of antibodies labeled with common fluorescent agents such as FITC is low and it is easy to miss the diagnosis.

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