[Ultrastructural analysis as a method of studying bacteremia in infectious diseases].

To study bacteremic processes with transmission electron microscopy, blood groups were examined in the representative groups of patients with typhoid fever, generalized forms of yersinosis, pseudotuberculosis, Flexner's shigelosis, and Sonne's shigelosis at different stages of acute cyclic diseases and in those with chronic Salmonella typhi carriage. Bacteremia of typical unaltered causative organisms is shown to occur only in the feverish period of disease. The morphofunctional organization of a causative agent in this period is similar to that of museum bacterial strains, except that the bacteria circulating in the blood of patients have vesicles that are morphologically equivalent to endotoxin. In reconvalescence, the blood circulation of causative organisms continues, but they appear as morphologically changed bacteria and as forms with their defective cellular wall (spheroplasts and protoplasts). Transmission electron microscopy reveals bacteria of other systematic groups in the patients' blood when acute Salmonella typhi carriage is under way or when there are typhoid fever-induced complications or relapses, clinically unfavorable running of typhoid fever, generalized forms of yersinosis and pseudotuberculosis are present. In chronic Salmonella typhi carriage, the patients' blood displays altered bacterial cells and forms with defective cell wall, among them there are prominent morphological types that are structurally identical to uncultured bacterial forms. The study of blood samples from infected patients has show that transmission lectron microscopy can be used to detect blood circulating microorganisms at different stages of acute and chronic patterns of an infectious process.