Microbiological diagnosis of Chlamydia trachomatis infection

Abstract

The etiological diagnosis of what is today known as infection by Chlamydia trachomatis was first made possible in 1907 when Halberstaedter and von Prowazek identified inclusions in conjunctival scrapings by means of Giemsa staining. C. trachomatis was originally classified as a virus, and the culture systems used were those for viruses. Macchiavello was the first to describe the isolation of C. trachomatis in embryonated hens' eggs (1944), but the first isolation is usually credited to T'ang and co-workers (1957), also using eggs. A major step in the understanding of chlamydial infections was made in 1965 when Gordon and Quan published a paper on the use of irradiated McCoy cells for isolation purposes. This technique made it possible to perform cultures from genital specimens with simplicity in comparison to isolation from eggs. Various culture techniques have been developed parallel to the expanding knowledge of the basic biology of the genus Chlamydia. McCoy cells (mouse fibroblasts), HeLa 229 (derived from human cervical carcinoma cells) and BHK-21 cells (baby hamster kidney cells) are the cell types regularly used for the culture of C. trachomatis. The principles underlying the various culture techniques are discussed. A description of the original irradiated McCoy cell system and the simplified, sensitive technique using cycloheximide-treated McCoy cells are given in this paper.

Immunodiagnosis of ocular chlamydial infection

“…Since trachoma presents in various clinical forms, and in babies less than six months of age may mimic bacterial conjunctivitis characterized by moderate to severe papillary hyperplasia without a follicular reaction, an immunologic test may quickly settle the diagnosis. Even in older babies (over 6 months) typical corneal involvement may not be present and follicles may be scanty, thus sometimes making a clin- Although the immunofluorescence test surpasses other techniques when serotyping of chlamydial isolates becomes necessary for epidemiological reasons, it is not an easy technique and at the present cannot be automated [7,23]~_ ELISA appears to be an answer to the genuine desire for reproducibility and automation. The various serotypes of chlamydia appear to possess genus-specific, species-specific, subspecies-specific, and typespecific antigens.…”

Zinc and Chlamydia trachomatis

“…These microorganisms cause a variety of infections in humans and other animals (16). Cultivation of these organisms in the laboratory may be difficult and time consuming unless certain procedures are performed (16,17). These organisms are obligatory intracellular parasites and are currently isolated most often after growth in McCoy or HeLa cell cultures (16,17).…”

“…Cultivation of these organisms in the laboratory may be difficult and time consuming unless certain procedures are performed (16,17). These organisms are obligatory intracellular parasites and are currently isolated most often after growth in McCoy or HeLa cell cultures (16,17). Because of the difficulty in propagating these microorganisms, numerous special techniques have been advocated.…”

“…Most frequently recommended are techniques that inhibit the McCoy or HeLa cells such as cycloheximide treatment, or less often irradiation or iododeoxyuridine ( 17-2 1). Because Chlamydia and mammalian cells have net negative surface charges (13,22), other techniques to increase infectivity have been the use of polycations such as diethylaminoethyl (DEAE)-dextran and centrifugation (17,18,20,23). Different types of C. trachomatis may respond in a different manner to these various treatments (16,17).…”

The In Situ Polymerase Chain Reaction for Detection ofChlamydia trachomatis

“…For a long time, the cell culture method established 30 years ago was the technique of choice to detect the intracellular bacteria (Ripa 1982). This method was succeeded by techniques such as the direct immunofluorescence test (DIF, Syva Micro Trak) and enzyme immunoassays (EIA), which can be routinely applied to large pools of samples (Domeika et al 1994).…”