Mycoplasma Infections: Infections with species of the genus MYCOPLASMA.Mycoplasma: A genus of gram-negative, mostly facultatively anaerobic bacteria in the family MYCOPLASMATACEAE. The cells are bounded by a PLASMA MEMBRANE and lack a true CELL WALL. Its organisms are pathogens found on the MUCOUS MEMBRANES of humans, ANIMALS, and BIRDS.Mycoplasma pulmonis: A species of gram-negative bacteria highly pathogenic to RATS and MICE. It is the primary cause of murine respiratory mycoplasmosis.Mycoplasma fermentans: A species of the genus MYCOPLASMA, originally isolated infrequently from the lower genital tract of humans, and possessing uncertain pathogenicity. The incognitus strain of M. fermentans has been identified in necrotizing lesions of multiple organs from AIDS and non-AIDS patients dying of an acute influenza-like disease.Mycoplasma hyorhinis: A species of gram-negative bacteria and a common inhabitant of the NASAL CAVITY of both healthy and diseased PIGS. It is a common secondary invader in MYCOPLASMAL PNEUMONIA OF SWINE.Pneumonia, Mycoplasma: Interstitial pneumonia caused by extensive infection of the lungs (LUNG) and BRONCHI, particularly the lower lobes of the lungs, by MYCOPLASMA PNEUMONIAE in humans. In SHEEP, it is caused by MYCOPLASMA OVIPNEUMONIAE. In CATTLE, it may be caused by MYCOPLASMA DISPAR.Mycoplasma pneumoniae: Short filamentous organism of the genus Mycoplasma, which binds firmly to the cells of the respiratory epithelium. It is one of the etiologic agents of non-viral primary atypical pneumonia in man.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Antibodies: Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).Mycoplasma hominis: A common inhabitant of the vagina and cervix and a potential human pathogen, causing infections of the male and female reproductive tracts. It has also been associated with respiratory disease and pharyngitis. (From Dorland, 28th ed)Mycoplasma genitalium: A species of gram-negative bacteria originally isolated from urethral specimens of patients with non-gonoccocal URETHRITIS. In primates it exists in parasitic association with ciliated EPITHELIAL CELLS in the genital and respiratory tracts.Mycoplasma mycoides: The etiological agent of contagious pleuropneumonia (PLEUROPNEUMONIA, CONTAGIOUS) of cattle and goats.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Antibody Specificity: The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.Mycoplasma hyopneumoniae: A species of gram-negative bacteria that causes MYCOPLASMA PNEUMONIA OF SWINE. The organism damages the CILIA in the airways of the pig, and thus compromises one of the most effective mechanical barriers against invading pathogens. The resulting weakening of the IMMUNE SYSTEM can encourage secondary infections, leading to porcine respiratory disease complex.Mycoplasma bovis: A species of gram-negative bacteria causing MASTITIS; ARTHRITIS; and RESPIRATORY TRACT DISEASES in CATTLE.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Mycoplasma gallisepticum: A species of gram-negative bacteria causing chronic respiratory disease in POULTRY.Mycoplasma penetrans: A species of gram-negative, facultatively anaerobic bacteria. This organism shows remarkable pathobiologic properties: it adheres to cell surfaces, deeply penetrates into the cell, and strongly adsorbs human red blood cells and human CD4+ lymphocytes and monocytes. M. penetrans was first isolated from the urogenital tract of patients with AIDS and high frequencies of antibodies to it are seen in HIV-infected patients.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Mycoplasma agalactiae: A species of gram-negative bacteria causing contagious agalactia of SHEEP and GOATS.Mycoplasma synoviae: A species of gram-negative bacteria pathogenic to CHICKENS; TURKEYS, and guinea fowls. It causes disease in a wide variety of organs and tissues including JOINTS, tendon sheaths and the RESPIRATORY TRACT.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Antibodies, Neutralizing: Antibodies that reduce or abolish some biological activity of a soluble antigen or infectious agent, usually a virus.Acholeplasma: A genus of gram-negative organisms including saprophytic and parasitic or pathogenic species.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Antibody Affinity: A measure of the binding strength between antibody and a simple hapten or antigen determinant. It depends on the closeness of stereochemical fit between antibody combining sites and antigen determinants, on the size of the area of contact between them, and on the distribution of charged and hydrophobic groups. It includes the concept of "avidity," which refers to the strength of the antigen-antibody bond after formation of reversible complexes.Mycoplasma arthritidis: A species of gram-negative bacteria causing purulent POLYARTHRITIS in RATS.