The use of thick sections with transmission electron microscopy in combination with scanning electron microscopy to study the attachment of Neisseria gonorrhoeae to vero cells infected with Chlamydia trachomatis

Abstract

Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) are well known pathogens associated with sexually transmitted disease. Clinical studies have shown that these organisms are frequently found together, and it has been suggested that gonorrhoeae be used as a marker for chlamydial infections. The reason for the high rates of co-infection is not known. However, in vitro studies (Ng et al. manuscript in preparation) have shown that the adsorption of NG to Vero cells pre-infected with CT is increased at least twenty times compared with that obtained with non-infected cells. In order to determine the areas of attachment and the fine structure of the attachment sites of the gonococci to the CT infected Vero cells, both transmission electron microscopy (TEM) using thick (0.25-0.5μm) sections and scanning electron microscopy (SEM) were used.To prepare samples for TEM, Vero (African green monkey kidney) cells were grown in T-flasks for 48h in M199 + 10% fetal calf serum at 37C in an atmosphere containing 5% CO2.