The goal - to study the frequency of detection and levels of Shiga toxin in the feces ofpatients with HIV infection at the stage of secondary diseases in the presence of mono and mixed O-antigens of intestinal bacteria. Materials and methods In 2012-2014 there were examined 123 patients with 4A, 4B, 4C- HIV infection, without diarrhea. The average age ofpatients accounted for 36,8 ± 7,8 years. The control group was consisted of 40 blood donors. In paired stool samples by means of the reaction of coagglutination (RCA) on slides there were tested LPS/O-antigens as markers of causal pathogens of major intestinal infections, Shiga toxin antigen and levels of IgG-immune complexes (IgG-IC in RCA on the plates) in patients with mono and mixed O-antigen in feces. Results There were established the excess of detection rate and titers of antigen Shiga toxin in stool in patients with HIV in comparison with donors, an gain of these indices in mixed infection, and a downward trend of IgG-IC levels in the feces in all cases of HIV-infection if compared with blood donors (p ≤ 0.01). Conclusion Detection of mono- and mixed-O-antigens in the feces of patients with HIV infection, an gain in titers and the frequency of the detection of Shiga toxin antigen, declined IgG-IC levels in feces indicate to pronounced intestinal dysbiosis and disturbed production of specific antibodies in patients with HIV infection at the stage of secondary diseases.

The goal was to establish the frequency of detection of LPS O antigens of common causative agents of intestinal infections in HIV-infected patients at the stage of secondary diseases. Materials and methods. The study included 48 HIV-infected patients at the stage 4A, 4Б, 4B (25 men and 23 women), without diarrhea, a mean age ofpatients was 36,78 ± 7,8 years. Stool samples (2-4 samples from patient in interval of 5-7 days) were studied for the presence of LPS/O-antigens of S.sonnei, S.flexneri 1-5, 6, Salmonella sgr. B, C1, C2, D, E, Y.pseudotuberculosis I, III, Y.enterocolitica 03, 09, Campylobacter (C.jejuni, C.coli, C.lari) in coagglutination. Results. It was found that HIV-infected patients at the stage of secondary diseases have relatively high presence of LPS/Oantigens of various pathogens - Shigella, Salmonella, Yersinia, in feces (72, 55%). But Campylobacter antigens were relatively rare. In stages 4A, 4Б and 4В overall detection rate of LPS/O-antigens in stool samples did not differ significantly and was 64,3%, 91,3%, 68,6%, respectively (r ≥ 0,05). Conclusion. The high content of LPS/O-antigens may increase the toxic load in patients with HIV infection, including the immune system.

The aim is to determine the frequency and dynamics of detection of specific lipopolysaccharide (LPS) O-antigens LPS/O-antigens of causative agents in hospitalized diarrhea patients. Materials and methods. A total of 146 hospitalized diarrhea patients were examined with the use of an immunological method of the reaction of coagglutination (RCA) for the presence of LPS O-antigens of Shigella, Salmonella, Yersinia and Campylobacter in feces as markers of major intestinal infections pathogens. The control group was consisted of 40 blood donors. Results. In acute diarrhea patients there was detected the predominance of Yersinia and Salmonella LPS O-antigens over Shigella and Campylobacter; the high frequency of intestinal bacterial mixt-infection in total (68%), as well as elevated rate incidence of Shigella, Salmonella, Campylobacter, Yersinia antigens in mixt-infections in comparison with those in monoinfections (24%). The total O-antigen "load" in patients with mixt-infection was 3 times higher than in patients with monoinfections; with the increasing of LPS/O-antigen "load" the rate of Salmonella inoculation declines. Conclusion. Under the same severity of the clinical course of the disease, the decline of Salmonella inoculation rate in cases of high antigenic "load" may indicate to the presence of the phenomenon of summation of toxic effects of LPS O-antigens when the concentration of each pathogen in the feces is insufficient (for inoculation) for bacteriological examination.