The purpose of the study was to determine the specificity and sensitivity of the immunoenzymatic test system that detects antibodies against the antigens of these bacteria in order to evaluate antiendotoxic immunity against GShPB endotoxins. It was found that flat bottom polystyrene solid phase carrier was selected for the proposed experimental test system for the detection of endotoxins of these bacteria by IFA method. The sensitivity of the recommended test system was 75% in colon dysbiosis, 76% in acute tonsillitis, 89% in acute bronchitis, and 95% in urinary tract infections, and the specificity was 5-25%, thus the diagnostic value of this test system it was proved for the first time.