Chlamydia trachomatis: milestones in clinical and microbiological diagnostics in the last hundred years: a review

Chlamydia trachomatis an obligate intracellular, Gram-negative bacterium is the causative agent of several acute or chronic, local and systemic human diseases such as trachoma, oculogenital and neonatal infections. It was discovered in 1907 by Halberstaedter and von Prowazek who observed it in conjunctival scrapings from an experimentally infected orangutan. In the last hundred years the detection and study of the intracellular pathogens, including chlamydiae, passed through an enormous evolution. This memorial review is dedicated to these important research and diagnostic discoveries and to the scientists who significantly contributed to this evolution starting from the application of simple light microscopy through the cell culture technique, antibiotic susceptibility, antigen and antibody detection, serotyping, to the real-time nucleic acid amplification and restriction fragment lengths polymorphism analysis. Although the majority of these old and new excellent diagnostic methods have been introduced into the rutine practice, the trachoma has remained one of the leading causes of blindness, and oculogenital chlamydial infections still are the most frequent sexually transmitted bacterial diseases, furthermore lymphogranuloma venereum is a disease emerging in the developed countries at the beginning of the 21 st century.