[Evaluation of antibiotic sensitivity of microorganisms, which were isolated from patients with acute pyelonephritis in the stage of purulent inflammation and located inside red blood cells (in vitro experiment)].

AIM: To study the antibiotic sensitivity of strains of microorganisms isolated from patients with a purulent stage of acute pyelonephritis and located inside the erythrocytes. MATERIALS AND METHODS: In this study, a total of 15 strains of microorganisms isolated from the blood of patients with a purulent form of acute pyelonephritis were used. The bacteria were detected and identified in the blood of patients using a modern molecular genetic method, fluorescent in situ hybridization (FISH), and the classical bacteriological study was done to isolate blood cultures of microorganisms. When studying the effect of antibiotics on the microorganism strains located inside red blood cells, the method of staged lysis was used. RESULTS: It was found that microorganisms isolated from patients with a purulent stage of acute pyelonephritis and, subsequently, inside red blood cells (in vitro experiment) in 80% of cases were resistant to antibacterial drugs of different groups (fluoroquinolones, aminoglycosides, macrolides, phosphonic acid derivatives). Outside of red blood cells, the same pathogens were sensitive to the antibiotics used in the work. Apparently, it is possible to consider the resistance to antibiotics of uropathogens located inside red blood cells as a result of insufficient intracellular concentration of the drug even when it is delivered by the method of stepwise lysis. CONCLUSION: When treating patients with acute pyelonephritis in the stage of purulent inflammation, it is necessary to consider that microorganisms can penetrate into red blood cells. In vitro experiments have shown that microorganisms inside red blood cells exhibit antibiotic resistance to antibacterial drugs of different groups. It is necessary to further study the intraerythrocytic microorganisms in the purulent stage of acute pyelonephritis, as a new pathogenesis mechanism of its development. Perhaps, these results can result in revision of the principles of antibiotic therapy.

[The additional criterion for the diagnosis of purulent-destructive forms of acute pyelonephritis].

AIM: to develop an additional criterion for objective diagnosis of purulent-destructive forms of acute pyelonephritis. MATERIALS AND METHODS: A total of 35 blood samples from patients with acute pyelonephritis aged from 19 to 85 years (mean age was 52 years) were studied. For the analysis, a classical bacteriological method of isolating blood culture and a modern molecular genetic method of fluorescent in situ hybridization (FISH) using DNA probes complementary to species-specific regions of the 16S rRNA gene of microorganisms were used. The obtained results were processed using the Statistica 6.0 program. RESULTS: The bacteriological study showed that only in one patient (2.9%) a blood culture was positive, whereas with FISH, polymicrobial infection consisting of two associates was observed in five patients (14.3%), and 207 specific luminescence from different DNA probes were detected in blood samples. The associations of members of the Enterobacteriaceae with S. aureus were 2.4 times more frequent than associations of the Enterobacteriaceae with S. epidermidis, indicating a development of the polymicrobial infection and, accordingly, the development of purulent stage of acute pyelonephritis. CONCLUSION: For the diagnosis of acute pyelonephritis, we suggest to use an additional criterion, which consists in applying of FISH method for the detection and simultaneous identification of bacteria that were adhered on the surface of erythrocytes and located intracellularly. This method may allow for the differential diagnosis of serous and purulent stages of acute pyelonephritis.

Role of Biological Characteristics of Staphylococcus epidermidis in Intraerythrocytic Invasion and in Modulation of Erythrocyte Catalase and Superoxide Dismutase Activities in Experimental Generalized Infection.

Studies on mouse model of generalized Staphylococcus epidermidis infection have demonstrated that erythrocytes more often contained microorganisms with pronounced antihemoglobin activity and less frequently with hemolytic activity. Infection with S. epidermidis strains characterized by pronounced hemolytic or antihemoglobin activities was associated with inhibition of erythrocyte catalase and superoxide dismutase activities in all cases, except infection with strains with high antihemoglobin activity, when superoxide dismutase activity increased.

The influence of non-tuberculous mycobacteria on the interaction of opportunistic microorganisms with erythrocytes.

Getting into a weakened organism, non-tuberculosis mycobacteria (NTMB) contact not only with the cells of the microorganism but also with the microflora of the human body; however, these interactions are poorly understood. The purpose of this work was to study the effect of NTMB supernatants on the properties of conditionally pathogenic microorganisms in their interaction with red blood cells. We used strains of non-tuberculous mycobacteria Mycobacterium iranicum and M. rutilum, as well as strains of Staphylococcus epidermidis and Escherichia coli. Using the fluorescence in situ hybridisation (FISH) method, the processes of adhesion to the surface of erythrocytes and the intra-erythrocyte penetration of cells of S. epidermidis and E. coli under the influence of NTMB supernatants were studied. To study changes in the haemoglobin molecule under the action of the supernatants of NTMB, spectral analysis was performed. Statistical processing was performed using STATISTIKA 6.0. The results showed that the supernatants of M. iranicum and M. rutilum increased the adhesion of conditionally pathogenic bacteria with a low level of AntiHbA to the surface of erythrocytes by 3-4 times. It also increased the intra-erythrocyte penetration of cells of S. epidermidis and E. coli relative to the control values. As a result of studying the haemoglobin spectrum of erythrocytes under the influence of M. iranicum, a decrease in the optical density values of oxyhaemoglobin by a factor of 2 relative to the values in the control sample was noted. Thus, the supernatants of NTMB have a multidirectional effect on the interaction of opportunistic microorganisms with erythrocytes, increasing the adhesive activity and the penetration of cells into the erythrocytes, as well as reducing the optical density of oxyhaemoglobin.