AgriMyc

Phylum	Class	Order	Family	Genus	Species/Subspecies

Species/Subspecies:

Pythium insidiosum

Categories:

Animal pathogen; human pathogen; plant pathogen

Etymology:

Genus name: to cause rot.
Species epithet: stealthy

Significance:

Pythios is a serious and life threatening disease, which can cause permanent damage and is difficult to cure.
[Important]

Geographic distribution:

Tropical and subtropical as well as some temperate areas of America, Africa and Asia , where it occurs in moist and swampy areas with dense vegetation .

Taxonomy:

Phylum	Class	Order	Family	Genus
Oomycota	Oomycetes	Peronosporales	Pythiaceae	Pythium

Note that members of phylum Oomycota do not belong to the actual fungi (Kingdom: Fungi), but belong to a separate group (Kingdom: Chromista), which are also called water moulds (or water molds).

Macromorphology (smell):

Micromorphology:

On solid culture media as well as in plants and in animal tissue, coenocytic hyphae with a diameter of 4-10 µm develop.

Reproduction:

Producerar zoosporer med två flageller, som kan röra sig mot hud med sår eller lindriga skador (nötning) genom kemotaxi. Zoosporerna utsöndra ett klibbigt material (glykoprotein?), som gör att de kan fästa till ytor. Organismen måste passera en värdväxt, för att kunna producera zoosporer.

Spec. Char.:

The cell wall of P. insidiosum consists of β-glucans and cellulose. Thus, cellulose instead of chitin, unlike fungi. The cellmembrane also lacks ergosterol in contrast to most fungi.

Vector:

Some studies have shown that P. insidiosum can infect blood sucking insects, which then can transmit the disease to other mammals.

Reservoir:

Stagnant water and sometimes soil. Animals that wade through stagnant waters in tropical or subtropical areas are especially prone to infection.

Disease/effect:

Hosts/substrate	Disease/effect	Clinical picture or result
Horse. calves, sheep, dog, cat and humans	Pythiosis (swamp cancer), which can be cutaneous (in horses) or gastrointestinal (in dogs).	Ulcerative and destructive lesions of the skin or the intestine.
Lilies and grass (family Poaceae)	Pythiosis???	It is believed that the organism needs an intermediate host (plant) for a complete life cycle, which has, however, not been proved.

Genome Sequence:

ACC-No GenBank	Strain/Isolate	# of chrom	Size (Mbp)
GCA_001029375	Pi-s		47.9

Mitochondrial DNA sequence:

ACC-No GenBank	Strain/Isolate	Number of BP	Ref
NC_027966	Pi-S	54 989	# 64

18S rRNA Seq:

ACC-No GenBank	Strain/Isolate	Number of NT
AF289981	ATCC 58643	1790

ITS regions:

Taxonomy/phylogeny:

Note that this group of organisms does not belong to the kingdom Fungi but instead to the kingdom Chromista, and it is believed that they are closely related to brown algae and diatoms.

Comment:

P. insidiosum is the only species within this genus that can infect mammals. Other species are often plant pathogens and cannot infect mammals.

Reference(s):

No. 55

Updated:

2021-06-23

AgriMyc

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