Bactericidal action of ABO isoagglutinins at different dilutions of anti-ABO antibodies

Tendo em vista o grande polimorfismo dos sistemas de grupos sanguíneos e que uma das hipóteses para explicá-los seja a co-evolução com patógenos, esta pesquisa teve como objetivo avaliar a ação bactericida in vitro dos anticorpos anti-ABO sobre a bactéria Escherichia coli. Foi observada diferença significativa no crescimento bacteriano (p<0,0001) nas comparações do Grupo O, Grupo A, Grupo B e Grupo AB, quando comparados ao controle positivo, demonstrando o efeito bactericida dos anticorpos anti-ABO. Não houve diferença significativa (p > 0,05) intergrupos sanguíneos O, A, B e AB. Apesar de não haver diferença estatística (p > 0,05) intergrupos sanguíneos O, A, B e AB, o grupo sanguíneo AB apresentou menor ação bactericida. A partir da ação bactericida dos anticorpos anti-ABO, estes podem ser utilizados no futuro como alternativas não farmacológicas no auxílio de quadros clínicos de sepse.In view of the big polymorphism of the blood group systems and that the hypothesis to explain them is the co-evolution with pathogens, this research had as its objective to evaluate the bactericide action in vitro of the anti-ABO antibodies upon the Escherichia coli bacteria. It was observed a substantial difference in the bacterial growth (p<0,0001) in the comparisons of Group O, Group A, Group B, and Group AB when compared to the Positive Control, demonstrating the bactericide effect of the anti-ABO antibodies. There was no significant difference (p > 0,05) between the blood systems O, A, B, and AB. Although there was no statistical difference (p > 0.05) between blood groups O, A, B and AB, blood group AB had less bactericidal action. Based on the bactericidal action of anti-ABO antibodies, these can be used in the future as non-pharmacological alternatives to help with sepsis clinical conditions

Actividad bactericida de anticuerpos anti-ABO en colonias aisladas de Escherichia coli

The interaction between ABO antigens and microorganisms, including those present in the microbiota, has been studied about the possible action of antigens and ABO antibodies in susceptibility to infectious diseases. This research aimed to determine the minimum titer of the Escherichia coli bacteria capable of undergoing in vitro bactericidal action of human anti-ABO antibodies. The selection of blood samples was performed through a questionnaire, blood phenotyping (one volunteer of each ABO phenotype), and the titration of ABO antibodies. A bacterial suspension (inoculum) was prepared and added to the serum of the volunteers, followed by inoculation in Mueller Hinton Agar. After 24 hours, the results were read and interpreted with duplicate analysis. There was no significant difference in the bactericidal test between tests 1 and 2 in blood groups A, B, AB, O, and Positive Control. There was a significant difference in pure human serum when Group A x Positive Control was analyzed, Group B x Positive Control, Group AB x Positive Control, and Group O x Positive Control. There was no significant difference in the other dilutions. It is concluded that anti-ABO antibodies have a bactericidal effect when there is a high concentration of bacteria in the environment.Se ha estudiado la interacción entre antígenos ABO y microorganismos, incluidos los presentes en la microbiota, sobre la posible acción de antígenos y anticuerpos ABO en la susceptibilidad a enfermedades infecciosas. El objetivo de esta investigación fue determinar el título mínimo de la bacteria Escherichia coli capaz de sufrir la acción bactericida in vitro de los anticuerpos humanos anti-ABO. La selección de las muestras de sangre utilizadas se realizó mediante la aplicación de un cuestionario, fenotipado sanguíneo (un voluntario de cada fenotipo ABO) y la titulación de anticuerpos ABO. Se preparó una suspensión bacteriana (inoculo) y se agregó al suero de los voluntarios, seguido de la inoculación en Mueller Hinton Agar, luego de 24 horas, los resultados se leyeron e interpretaron con análisis por duplicado. No hubo diferencia significativa en la Prueba Bactericida entre las pruebas 1 y 2 en los grupos sanguíneos A, B, AB, O y Control Positivo. Hubo una diferencia significativa en el suero humano puro cuando se analizó el Grupo A x Control Positivo; Grupo B x Control Positivo; Grupo AB x Control Positivo y Grupo O x Control Positivo. No hubo diferencia significativa en las otras diluciones. Se concluye que los anticuerpos anti-ABO tienen efecto bactericida cuando existe una alta concentración de bacterias en el ambiente