Tatina Todorova

By Tatina T. Todorova, Gabriela Tsankova, Neli Lodozova and Tcvetelina Kostadinova

Tuberculosis (TB) and HIV/AIDS infection are one of the most ubiquitous and deadliest communicable diseases in the world. They cause millions of deaths each year and are recognized as major threats for public health worldwide. The corresponding pathogens (Mycobacterium tuberculosis and HIV) share overlapping epidemiology—they affect low-income countries and place an immense burden on their feeble health care systems. Over the last decades, the natural history of both diseases has changed; in addition to devastating single HIV and TB infections, the coinfection with both pathogens has emerged and has spread in pandemic scale. When present as dual infection in an individual, Mycobacterium tuberculosis and HIV potentiate each other and kill in cooperation the host. TB is the leading cause of death in HIV-positive patients and in turn HIV infection is the strongest risk factor for the development of new or reactivation of dormant TB disease. Both pathogens (as single or dual infection) provoke a robust immune response in the infected host but the immune system does not achieve to eliminate the infectious agent(s). The failure of immune defense results in vulnerable immune balance between the micro- and the macroorganism and often ends up in a fatal outcome.

Part of the book: Immunopathology and Immunomodulation

By Tatina T. Todorova, Neli Ermenlieva and Gabriela Tsankova

Vitamin B12 is a water-soluble vitamin and an important micronutrient with critical role in DNA, protein, and lipid synthesis. It is responsible for one-carbon metabolism and cell division of nervous and hematopoietic cells. Among its various functions, the role as immunomodulator in cellular immunity, especially in elevating the number of CD8+ cells and NK cells, attracts scientific interest. Many alternative anticancer and anti-inflammatory treatments involve the use of B12 together with other vitamins and nutrients, but still the scientific information is too obscure and insufficient. Controversial data link tumorigenesis with either increased or decreased B12 blood levels in different types of cancer. Dietary intake and additional supplement with the vitamin do not protect against cancer risk, but the dominant opinion is to integrate B12 as part of rational and healthy nutrition to ensure proper function of the immune system. This chapter will review in brief the most important facts for vitamin B12 functions and properties. We will try also to present in concise way the human immune system and the exact role of B12 in immune activity with emphasis on the questionable participation of vitamin B12 in the process of carcinogenesis and its significance as anticancer immunotherapy.

Part of the book: Immunotherapy

By Neli Ermenlieva, Gabriela Tsankova, Darina Naydenova, Tatina T. Todorova, Dayana Tsankova and Emilia Georgieva

Bioterrorist attacks are usually associated with airborne infections because of their easy dissemination and maximal effect on the human population. However, foodborne pathogens represent potential bioterrorist weapons, as the consumption of safe food affects every individual in the society. Most of the foodborne microorganisms can be readily isolated from natural sources and can cause severe outbreaks with a number of hospitalized persons. Biological agents, which may contaminate food products, are bacteria, viruses, yeasts, parasites, or chemical substances with microbial origin. They cause more than 200 diseases—ranging from diarrhea to cancers. Typical symptoms of food poisoning are abdominal cramps, nausea, vomiting, upset stomach, diarrhea, fever, dehydration, and others. Most isolated bacterial agents responsible for foodborne infections include bacteria from genera such as Salmonella, Shigella, Bacillus, Clostridium, Listeria, Campylobacter, Escherichia, Staphylococcus, Vibrio, Enterobacter, and Yersinia. In this chapter, we discuss the bacterial species causing food poisoning in the context of a potential bioterrorist attack. We review in a concise manner their morphological and biochemical characteristics, as well as the treatment and possible prevention measures. Popular examples of attacks with food poisoning agents and their impact on the society are also given.

Part of the book: Food Safety