What are obligate intracellular viruses?
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.
Which is an obligate intracellular parasite?
Viruses are obligate intracellular parasites that can exist as potentially active but inert entities outside of cells.
What do obligate intracellular pathogens do?
Obligate intracellular bacterial pathogens are organisms that absolutely require an eukaryotic host to survive and replicate, and therefore they have developed virulence factors to prevent diverse forms of host cell death and conserve their replicative niche.
What defines an obligate intracellular bacteria?
Obligate intracellular bacteria require a host cell in which to replicate, depending on a multitude of adaptative strategies to overcome antibacterial responses and successfully establish infection. Many members of this group are pathogenic to humans (e.g., Coxiella burnetti, Chlamydia …
Which of the following is 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 [3].
Why are viruses called obligate intracellular parasites?
Why are viruses called obligate intracellular parasites? They must use a host cell’s nucleotides for transcription and replication. They must use a host cell’s ribosomes to synthesize proteins.
What are examples of intracellular pathogens?
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 is obligate pathogen?
Obligate pathogens require a host to fulfil their life cycle. All viruses are obligate pathogens as they are dependent on the cellular machinery of their host for their reproduction.
What is obligate parasite example?
Obligate parasites are organisms that require a host for the completion of their life cycle. The obligate parasites cannot synthesise their food, instead, they are dependent on the host for food. Bacteria, plants, and fungi all have examples of obligate parasites. All viruses are known to be obligate parasites.
Where do obligate intracellular parasites live?
Intracellular parasites (e.g. toxoplasma, plasmodia, etc.) reside within specialized membrane surrounded vacuoles named parasitophorous vacuoles. Therefore, these intracellular parasites are cut off from vesicular membrane traffic within the host cells.
What is the difference between intracellular and extracellular pathogen?
Bacteria have historically been divided into two distinct groups: extracellular bacteria, which exist as free-living organisms in their environmental niches, and intracellular bacteria, which infect and replicate inside host cells.
What is an obligate intracellular bacterium?
Why are viruses called obligate intracellular parasite?
All viruses are obligate parasites; that is, they lack metabolic machinery of their own to generate energy or to synthesize proteins, so they depend on host cells to carry out these vital functions.
What is an obligate pathogen?
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.