New Discoveries in Toxins from Gram-Positive Bacteria, Listeria monocytogenes

The toxins that microbe forms are by-products of metabolism, most of which are proteins or polypeptides. Despite efforts to control the spread of Listeria monocytogenes through improved food safety measures, listeriosis remains a public health concern. The toxins produced differ according to the type of microbe. Listeria monocytogenes may contaminate various foods, whether canned or not, including vegetables, milk, cheese, meat, and fish, and causes a severe disease called listeriosis, accompanied with different symptoms such as fever, vomiting, and diarrhea. These symptoms are self-limited in immunocompetent patients while they are more serious in immunocompromised patients, including newborns, elderly patients, pregnant women, etc., and may lead to blood poisoning and meningitis. Generally, the death rate due to infection with these bacteria is about 20%. To date, Listeria outbreaks are recorded over the word and continue to rise, especially with the development of resistance toward the key-antibiotics used to treat listeriosis, which requires more attention to find new and sustainable prevention strategies to tackle the spread and emergence of listeriosis over the world.