Mechanism of the Gut Microbiota Colonization Resistance and Enteric Pathogen Infection.

The mammalian gut microbial community, known as the gut microbiota, comprises trillions of bacteria, which co-evolved with the host and has an important role in a variety of host functions that include nutrient acquisition, metabolism, and immunity development, and more importantly, it plays a critical role in the protection of the host from enteric infections associated with exogenous pathogens or indigenous pathobiont outgrowth that may result from healthy gut microbial community disruption. Microbiota evolves complex mechanisms to restrain pathogen growth, which included nutrient competition, competitive metabolic interactions, niche exclusion, and induction of host immune response, which are collectively termed colonization resistance. On the other hand, pathogens have also developed counterstrategies to expand their population and enhance their virulence to cope with the gut microbiota colonization resistance and cause infection. This review summarizes the available literature on the complex relationship occurring between the intestinal microbiota and enteric pathogens, describing how the gut microbiota can mediate colonization resistance against bacterial enteric infections and how bacterial enteropathogens can overcome this resistance as well as how the understanding of this complex interaction can inform future therapies against infectious diseases.

Distribution of Toxoplasma gondii IgM and IgG antibody seropositivity among age groups and gestational periods in pregnant women.

Background: Toxoplasmosis is a globally distributed parasitic disease. The present study aimed to estimate the prevalence and geographic distribution of toxoplasmosis, as well assess the risk of animal contact in disease development and determine the percentage of toxoplasmois-associated IgM and IgG seropositivity among different age groups. In addition, it aimed to estimate the proportion of toxoplasma IgM seropositivity among pregnancy trimesters. Methods: A total of 500 pregnant women were included in this study. From each participant, a 5-ml venous blood sample was collected and centrifuged to obtain serum that was tested for Toxoplasma gondii IgM and IgG antibodies using immunochromatographic testing and ELISA. Results: The overall seroprevalence of toxoplasmosis was 24.8%, with rates of acute infection of 8%. Among positive cases in every trimester, 54.34% of first trimester positive cases had a serologic marker of acute toxoplasmosis. Out of the 40 pregnant women with previous history of cow/buffalo contact and toxoplasmosis, 40% were seropositive for toxoplasma IgM; and out of 30 women with prior history of dog contact, 16.66% had serological marker of acute toxoplasmosis. Conclusions: In this study, there is a high prevalence of toxoplasmosis and contact with domestic animals is a risk factor for this illness. Therefore, it is necessary to test every pregnant women for toxoplasmosis and distinguish the type of infection, as well as the conduction of public health education programs to generate the awareness.