| Streptococcus pneumoniae is a common gram-positive diplococcus, also known as pneumococcal. As a kind of pathogenic bacteria, streptococcus pneumoniae, whose infection has become a serious public health problem worldwide, can exist in nature widely. It is main cause of inflammation, tract toxic disease, hypersensitivity disease, etc.Pneumococcal bacteremia shows high morbidity and mortality in newborns, infants and young children of 2 years or younger, and the aged. For a long time, antibiotics have been used against pneumococcal infections as the main clinical treatment, however, with the more and more widely using of antibiotics, resistance of pneumococcus to vancomycin, as well as to drugs like penicillin, are on the rise. Therefore, it is urge to widely applied a preventive measure which bases on immunization with a tumor vaccine. So far, in the general population, it remains unclear about the details of the virological and biochemical responses in the condition of nature, or the number of antibodies produced during responses. In this paper, in order to understand the level of immune responses of healthy people in the condition of nature, is tested resistant pneumococcal capsular polysaccharide IgG in the serum by enzyme-linked immunosordent assay.The purpose of this study is to obtain a more comprehensive data on the level of antibodies in the serum of un-vaccinated people, to find out whether a susceptible crowd exists, and to produce pre-clinical data information for 23 pneumococcal polysaccharide vaccine.An standardized ELISA Method(Pn PS ELISA) which is recommended by the WHO was used to test the concentration of 12 types of capsular polysaccharide IgG antibodies in human serum. Also, in order to detect whether streptococcus pneumoniae antibody level in the crowd changes or not, 253 blood samples were tested and divided by age, sex, blood type and area.ELISA, which is abbreviation for Enzyme Linked Immunosorbent Assay, has the characteristics of high sensitivity and strong specificity. In order to eliminate the differences between laboratories and to ensure the consistency of standard and data of immune effects’ evaluation by regulators, the WHO recommends the standardized method of ELISA(Pn PS ELISA) to detect the serum concentration of capsular polysaccharide IgG antibodies. This method not only requires special reagents(e.g., standard and quality control serum), but also requires optimized and standardized operation during the whole testing process. In addition, the experimental materials, pharmaceuticals, reagent are strictly selected and standardized validated.When testing the level of anti-streptococcus pneumoniae capsular polysaccharide IgG antibodies in the serum, first of all, a glycocalyx ferment plate is used for 5 hours at 37 degree centigrade. After that, standard and inspected serum is added to the washed ferment plate. Stay them for the night(< 18 h) and then cleaned the plate again. Secondly, alkaline phosphatase tagged Goat Anti-human IgG(1:2000) is added for 2 hours at 20—25 degree centigrade, then the plate is cleaned. Thirdly, the substrate is added to avoid light and develop colors for 2 hours, and absorption values in a range of 405-630 nm. At last, calculate Ig G antibody concentration in detected sera according to the number of IgG in standard serum.Input antibody levels result data of the 12 pneumococcal types into SPSS 19.0, then get conclusions that whether there is significant differences among different ages, sexes, blood types and areas that belong to the same pneumococcal antibody level. In this experiment, it is found that neither gender, blood type nor age difference are exposure or infection factors of the 12 pneumococcal types under natural conditions. |
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