Streptococcal pneumoniae is the leading cause of community-acquired pneumonia, meningitis, and otits media in children. The emergency of penicillin-resistant strain has made difficulty in the management of pneumococcal infection, and rapid and
accurate
identification become more important.
The accurate identification of S. pneumoniae in the clinical microbiology laboratory can be accomplished in many ways. Although the Quellung reaction with polyvalent antiserums is the most accurate and specific test for identifying and typing of
pneumococci, it is no longer used routinely in the diagnostic laboratory. Other serologic tests, such as latex aggluntination and coagglutination, provide simple and more rapid serological identification of S. pneumoniae from culture.
However, pneumococcal strains lacking the same capsular polysaccharide in the capsule cannot be identified by serological tests, and false-positive results may occur because of cross-reactions with other bacteria which possess an antigen similar
to
pneumococcal polysaccharide, and equivocal serological reactions may occur when older colonies or mixed cultures are used.
Aughors tried to make a species -specificmonoclonal antibody to S. pneumoniae, and assessed the sensitivity and specificity of the monoclonal antibody for diagnosis of pneumococcal infection. Female Balb/c mice immunized two times with whole-cell
suspension of clinically isolated S. pneumonioae(3×10E8 colony forming unit/0.1ml) by means of intravenousinjection. Cell fusion was performed on 10 day after 1st immunization using 50% PEG 1,500. Culture fluids of the growing hybridomas were
tested
for antibodies to S. pneumoniae whole cells in an ELISA. Two monoclonal antibodies HWPn1 and HMPn2 were isolated. And the immunoglobulin class of HMPn1 and HMPn2 were IgM respectively. to evaluate the sensitivity and specificity of a species
-specific
monoclonal antibodies HMP n1 and HMPn2, 24 strains of s. pneumoniae(target) and 11 miscellaneous bacteria (Streptococcus group A, B, C, D, F, G, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candidda
albicans) were tested by ELISA. Isolates of S. pneumoniae mainly from the respiratory tract. Blood and spinal fluid were cultured.
Miscellaneus 11 bacteria representing of those found in the respiratory tract were selected as the nontarget organisma. None of the strains(non-targe) tested treacted with the monoclonal antibody HMPn1, thus yielding a specificity of 100%, but
monclonal
antibody HMPn2 cross reacted with group C Streptococci. The monoclonal antibody HMPn2 cross reacted with group 2 reacted with all pneumococcal strain tested to yield a sensitivity of 100%.
Monoclonal antibodies HMPn1 and HMPn2 can be reacted until 3×10E3 CFU S. pneumoniae in dot-ELISA. Immunoglobulin clasws of monoclonal antibodies HMPn1 and HMPn2 are IgM respectively. No quellung reaction was observed in 5 cases of pneumococci
with
capsule.
The monoclonal antibodies MHPn1 and HMPn2 reacted with cell membrane of S. pneumoniae to yield positive test in indirect immunofluorescent assay.
The monoclonal antibody HMPn1 reacted with 35kd ANTIGEN BY Western-immunoblot, and the monoclonal antibody HMPn2 reacted with 30 and 34KD protein of S. pneumoniae.
In conclusion, the author made a monoclone whose supernatant HMPn1 reacted with 35KD protein of S. pneumoniae, and both of the sensitivity and the specificity of the species-specific monoclonal antibody HMPn1 turned out to be 100%, which suggest
the
monoclonal antibody HMPn1 can be used for research and diagnosis of S. pneumoniae in clinical laboratory.
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