[Serological researches in the bacterial respiratory tract infections (author's transl)].

Previous studies on the serological diagnosis of the lower respiratory tract infections caused by bacteria have been reviewed. The most significant results have been up to today obtained with the double immunodiffusion technique (Ouchterlony) for detecting different, specific and aspecific, bacterial precipitins in the serum of the patients, and with the immunoelectrophoresis which allows to distinguish specific precipitine lines from the aspecific ones. Among the other immunological methods, bacterial agglutination, passive haemagglutination, cross-over-immunoelectrophoresis, complement fixation, and immunofluorescence have been only occasionally used, but further comparative studies are needed and suggested to establish their diagnostic value. Other technical problems, as purity of antigens or cross-reactivity of antibody or antibodies level evaluation, are raised and discussed. Further improving of the serological methods would allow their routine use in clinical bacteriology as a useful tool in the assessment of pathogenicity of the bacterial species in the sputum and in the ethiological diagnosis of broncho pulmonary infections, at least of those cases in which exclusive relaying on sputum cultures could be fallacious.