[Contribution of recent methods to the diagnosis of Chlamydia infections].

Chlamydia trachomatis is the most common cause of non- and/or post-gonococcal urethritis in men. The infection is often silent in women, but may be complicated by salpingitis followed by tubal sterility. The direct diagnosis: Since the availability of monoclonal antibodies, the microscopic examination of a smear of the sample is once again a current technique. By using an immuno-fluorescent technique, it is possible to demonstrate the elementary corpuscules in the form of free extracellular particles. This methods is rapid and easy to perform. Culture: Nevertheless, culture remains the reference technique despite the fact that it only reveals "inclusions": clumps of reticulated particles. The technique is simplified by using microculture in flat bottomed microtitration plates, which enables a large number of isolations to be performed in one step. The visualisation by means of monoclonal antibodies is in perfect agreement with classical staining techniques. The serological diagnosis: Micro-immuno-fluorescence (MIF) is still the reference technique. ELISA occasionally fails to correlate with MIF. These discordances can be explained by the different antigens used: protein extracts bound to a support, in the case of ELISA, and whole live particles, in the case of MIF.