Host Defense against Microbial Infections
What cells are mainly responsible for immunity?
Lymphocytes are one of the main types of immune cells. Lymphocytes are divided mainly into B and T cells. B lymphocytes produce antibodies – proteins (gamma globulins) that recognize foreign substances (antigen) and attach themselves to them. B lymphocytes (or B cells) are each programmed to make one specific antibody.
What is the difference between intracellular and extracellular pathogens?
In this context, an extracellular pathogen is one that cannot survive inside the phagocyte once it has been ingested. 2. Intracellular pathogens –pathogens that can live inside of host cells, especially phagocytes. (A more narrow meaning with regards to the interaction of bacterial pathogens and the phagocytic cells.
Which of the following is an intracellular bacterial pathogen?
Classical examples of intracellular pathogens are Brucella abortus, Listeria monocytogenes, Chlamydia trachomatis, Coxiella burnetii, Mycobacterium tuberculosis, Salmonella enterica, and typical infectious diseases caused by them include brucellosis, listeriosis, tuberculosis, and salmonellosis (Pamer, 2008).
What are the two components of immune system?
The immune system is made up of two parts: the innate, (general) immune system and the adaptive (specialized) immune system. These two systems work closely together and take on different tasks.
What are the 3 major functions of the immune system?
The tasks of the immune system
- to fight disease-causing germs (pathogens) like bacteria, viruses, parasites or fungi, and to remove them from the body,
- to recognize and neutralize harmful substances from the environment, and.
- to fight disease-causing changes in the body, such as cancer cells.
What are three types of immunity?
Humans have three types of immunity — innate, adaptive, and passive:
- Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection. …
- Adaptive immunity: Adaptive (or active) immunity develops throughout our lives.
Why some bacteria are intracellular?
Some species remain in the vacuolar compartment, while others leave it to take up residence in the cytosol. Because of their desire to replicate within a host cell and keep it alive for this purpose, intracellular bacteria are generally not very toxic to the host and do not produce tissue-damaging bacterial toxins.
Is E coli an intracellular pathogen?
Intracellular bacteria in the pathogenesis of Escherichia coli urinary tract infection in children.
What are the 4 types of pathogenic bacteria?
4 Types of Pathogenic Bacteria Used in Bioterrorism
- Bacillus anthracis (Anthrax)
- Clostridium botulinum (botulism)
- Francisella tularensis subsp. Tularensis (valley fever)
- Yersinia pestis (the plague)
Which of the following is an example of an obligate intracellular pathogen?
Obligate intracellular parasites that infect humans include all viruses; certain bacteria such as Chlamydia and Rickettsia; certain protozoa such as Trypanosoma spp., Plasmodium, and Toxoplasma; and fungi such as Pneumocystis jirovecii .
Are all viruses intracellular?
Viruses are small obligate intracellular parasites, which by definition contain either a RNA or DNA genome surrounded by a protective, virus-coded protein coat. Viruses may be viewed as mobile genetic elements, most probably of cellular origin and characterized by a long co-evolution of virus and host.