The immune response to M. tuberculosis engages T-cell medicated reactions which determine the degree of resistance and also the clinical pattern of disease. Although antibodies produced by the infected host have yet no proven protection, they are appilicable for alternative diagnostic tests in tuberculosis. Preparation of purified antigens from Mycobacteria with specific antigenic determinants would improve serological diagnosis in tuberculosis. The antigen was prepared by extraction of M. tuberculosis with perchloric acid which was found to be major bands of 71, 42, 38 and 10 kD by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Thirteen sera from patients with active tuberculosis showed positive reactions to TB-P by ELISA, but the reaction to perchloric acid extract antigen is weaker than to PPD. The IgG subclass profiles to TB-P were IgG1, IgG2 and IgG4. By means of western blotting, the antibodies in the tuberculous patients showed the reaction with antigens of lower molecular weight such as 14, 12, 11 and 10 kD. These results suggested that the perchloric acid soluble antigen of M. tuberculosis might be more related with cell-mediated immune reactions rather than humoral immune reactions.
Antibodies ; Blotting, Western ; Diagnosis ; Diagnostic Tests, Routine ; Electrophoresis ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; Humans ; Immunoglobulin G ; Molecular Weight ; Sodium ; T-Lymphocytes ; Tuberculosis*

The peneicillin binding protein gene(mecA gene) is present in the methicillin-resistant Staphylococcus strains but not in the susceptible ones. The goal of the present study was to establish experimental evidences which might use polymerase chain reaction(PCR) for culture confirmation and eventually clinical diagnosis of methicillin resistant Staphylococcui. Two primers (5'-AAAATCGATGGTAAAGGTTGGC-3', 5'-AGTTCTGCAGTACCGGATTTGC-3') based on the known DNA sequence of the mecA gene from methicillin-resistant Staphylococcus aureus were used in PCRs to screen for the presence of this gene in Staphylococcal isolates from various clinical settings. When the primers were used to copy the DNA of the mecA gene, only 533 base-pair DNA fragment was appeared. The product indicates a positive PCR result for methicillin-resistant Staphylococcal isolates. In contrast, from the DNA of the methicillin-sensitive Staphylococcal isolates the 533bp was not amplified. Results obtained with PCR were generally consistent with those of standard microbiological assays. The mecA gene in methicillin-high resistant Staphylococci was located on the approximately 5.56kb Hind III restriction fragment. The 533bp probe was hybridized to the 5.56kb Hind III restriction fragment of mecA-positive S. aureus. No hybridization was occured in the mecA-negative strain. The mecA gene was cloned, named pHL-1201 and verified by colony hyhridization. The 533bp probe was hybridized to the approximately 5.56kb Hind III restriction fragment of the DNA obtained from pHL-1201. PCRs with the primers successfully distinguished methicillin-resistants from methicillin-susceptible strains of S. aureus and S. epidermidis.
Base Sequence ; Carrier Proteins ; Clone Cells* ; Cloning, Organism* ; Diagnosis ; DNA ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus ; Polymerase Chain Reaction* ; Staphylococcus aureus ; Staphylococcus*