Screening And Identification Of Lactic Acid Bacteria Resistant To Toxoplasma Gondii Infection

Toxoplasma gondii is an important zoonotic parasite.Humans are mainly infected by eating raw or undercooked meat containing tissue cysts.After infection,cysts can form in muscle,brain and other tissues and organs and remain for a long time to threaten human health.At present,T.gondii is mainly treated with antibiotics and other drugs,but there are side effects and drug resistance.The aim of this study was to screen lactic acid bacteria that can antagonize T.gondii infection,and to identify the strains and analyze the genes.In this study,6 strains of lactobacillus were screened by acid tolerance,bile salt and gastroenteric fluid test.After heat resistance,hemolytic,drug resistance and in vivo safety evaluation,5 strains of Lactobacillus plantarum and 1 strain of Lactobacillus muci reuteri were finally obtained,which were safe and had potential probiotic properties,and the target lactobacillus was screened by antagonizing T.gondii infection test.Finally,2strains of Lactobacillus plantarum HB and 6C were screened.Although they could not change the death outcome of T.gondii acute infected mice,they could prolong the survival time and reduce the number of cerebral cyst in chronic infected mice by 60.59%and 56.42%,respectively(p <0.05);the combination of the 2 strains could improve the antagonistic effect of the drugs on T.gondii and the reduction rates of cerebral cyst in chronically infected mice were 83.41% and 81.14%,respectively(p <0.05).The results of this study provide ideas and theoretical basis for the development of effective and safe antagonistic routes against T.gondii infection,and open up a new field for the research,development and utilization of lactic acid bacteria.In the future,resources will be explored in a new field and the mechanism of lactic acid bacteria antagonizing T.gondii infection will be further studied.