[Bacterial virulence factors and their role in the pathogenesis of pyogenic infections of the abdominal cavity and mediastinum].

Purulent peritonitis are caused predominantly by anaerobic bacteria which come from physiological intestinal flora. Mediastinitis is caused amidst other etiologic factors also by bacteria inhabiting the oropharyngeal region, as well as microorganisms causing diseases localized in the proximity of mediastinum. Anaerobic sporulating bacteria both Gram positive and negative cause often miscellaneous infections due to Staphylococcus aureus, Enterobacteriacae, Streptococcus, Enterococcus. It involves a group of bacteria which are able to produce a fibrin network in their proximity, to resist phagocytosis by their structures, to distruct the components of the complement system and immunoglobulins, to impair membranes of cells which leads by means of their factors of virulence to formation of defectuous immunity. Microbiological examination requires the material to be sent for anaerobic cultivation and the antimicrobial therapy must take into account its polymicrobic etiology. (Ref. 23.)