[The level of alcohol and titre of A and B group substances of the ABO system in blood samples infected by some strains of Escherichia coli].

Evaluating the results of sectional blood examinations for ethyl alcohol content is difficult due to the proceeding putrid and fermentative processes, in consequence of which endogenic ethyl alcohol is produced. Some difficulties also arise from estimating the results of serological investigations concerning the biological traces having been changed by putrefaction, where the presence of heterogenic antigens may be suspected. The putrid-fermentative processes are linked with the activity of microorganisms, particularly bacteria and yeast-like fungi. The first part of the paper deals with the bacterial flora in 50 sectional blood samples taken for routine determinations of ethyl alcohol content, thus with added sodium fluoride as bacteriostatic agent. The identification of the microorganisms cultured on differentiating and selectively differentiating media was carried out on the basis of the culture appearance, specimens stained by Gram's method, as well as biochemical examinations. From 16 studied samples of the sectional blood no strain of bacteria was cultured, mixed bacterial flora was isolated from the remaining ones (Tab. 1). Most numerous were Gram-negative bacteria (71%) among which E.coli appeared most frequently. Gram-positive claimed 28% of the cultured microflora, while anaerobes hardly 4%. In the second part of the paper, the selected strains of E. coli pertaining to serological groups: 02, 04, 06, 08, 09, 022, 025 were studied with regard to their possibility to produce ethanol as well as antigens A and B of AB0 system. E.coli strains were grown on broth medium containing glucose in concentration of from 0.00 to 27.75 mmol/l and human blood of 0 group collected from blood-donors on sodium citrate and CPD preservative with glucose in its content. Ethanol concentration in cultures was determined after 24 and 72 hours of incubation, by gas chromatography method, and glucose by enzymatic method. In serological investigations the material consisted of linen pieces being covered with 72-hour cultures of E.coli on broth and human blood of group 0. The study for the presence of the group substances A and B of AB0 system was performed by absorption method according to Holzer, and by absorption and elution method. In consequence of the studies it has been ascertained that sodium fluoride added as a bacteriostatic agent does not entirely inhibit the growth of bacteria, and especially bacteria Gram-negative appeared to be least sensitive to its action (Tab. 1). Selected strains of E.coli have differed with regard to the efficiency of ethanol production (Tab. 2). The level of produced ethanol depended on glucose concentration in the medium, temperature and the incubation time (Tab. 2, 3, 4 and Fig. 1). Under almost similar conditions the same strains produce more alcohol than on blood, which may give rise to supposition that the blood modifies the metabolism of bacteria (Tab. 4 and 5). The cultures of selected strains studied failed to reveal the presence of heteroantigens with properties of antigen A and B of AB0 system.