What are facultative intracellular bacteria?
Facultative intracellular parasites, for example, bacteria such as Francisella tularensis, Listeria monocytogenes, Salmonella typhi, Mycobacterium spp., and Neisseria meningitidis, are capable of living and reproducing either inside or outside host cells.
Are viruses intracellular facultative parasites?
Viruses are small and relatively simple microbes that cannot grow outside of living cells, that is, they are obligate intracellular parasites (Figure 1).
Is E coli facultative intracellular?
We are witnessing an increasing number of bacteria, previously described as extracellular, for which some strains show facultative intracellular characteristics such as Escherichia coli, Vibrio cholerae, and Acinetobacter baumannii.
Which parasite is the intra cellular parasite *?
Salmonella species are facultative intracellular parasites, capable of penetrating (invading), surviving, and often multiplying within diverse eukaryotic cell types, including epithelial and phagocytic cells.
What does facultative mean in microbiology?
Facultative means “optional” or “discretionary” (antonym obligate), used mainly in biology in phrases such as: Facultative biotroph, an organism, often a fungus, that can live as a saprotroph but also form mutualisms with other organisms at different times of its life cycle.
What are facultative parasites?
A facultative parasite is an organism that may resort to parasitic activity, but does not absolutely rely on any host for completion of its life cycle. Examples of facultative parasitism occur among many species of fungi, such as family members of the genus Armillaria.
Which of the following is a bacterial facultative intracellular pathogen?
Facultative intracellular bacteria, including Salmonella spp., Francisella spp., Legionella pneumophila, Listeria monocytogenes, Yersinia spp. and many others, can replicate in either niche.
Why is a virus considered an intracellular parasite?
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.
What is the difference between intracellular and extracellular infection?
Main. 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.
Why are viruses intracellular parasites?
Since viruses are obligate intraellular parasites, the term conveys the idea that viruses must carry out their reproduction by parasitizing a host cell. They cannot multiply outside a living cell, they can only replicate inside of a specific host.
What is the difference between facultative and obligatory intracellular parasites?
Facultative intracellular parasites are capable of living and reproducing in or outside of host cells. Obligate intracellular parasites, on the other hand, need a host cell to live and reproduce. Many of these types of cells require specialized host types, and invasion of host cells occurs in different ways.
How do intracellular parasites enter a cell?
When an intracellular parasite goes to enter a host cell, it is particular about the type of host cell. This is because most intracellular parasites are able to infect a few different cell types. The entrance of these host cells will differ between intracellular parasites. Not all intracellular parasites will enter a cell the same way.
Is polypolypodium an intracellular parasite?
Polypodium is a metazoan intracellular parasite, distinct from most if not all other intracellular parasites for this reason. When an intracellular parasite goes to enter a host cell, it is particular about the type of host cell. This is because most intracellular parasites are able to infect a few different cell types.
What is a facultative intracellular pathogen?
The Inconsistency of the Label Facultative Intracellular Pathogen. In the term “facultative intracellular pathogens” the adjective “facultative” refers to “intracellular” to indicate that these infectious agents are able to replicate inside and outside cells (Moulder, 1985).