Name: spirochete shape, motion, and disease
Uploaded: 2025-06-12T09:21:19.000Z
Duration: 1 min 30 s
Channel: JoVE

Krętki to Gram-ujemne, zwinięte bakterie sklasyfikowane w gromadzie krętków. Endoflagella w krętkach wytwarza ruch podobny do korkociągu, umożliwiając ruch przez lepkie materiały lub tkanki. Rodzaj Spirochaeta obejmuje krętki beztlenowe i fakultatywnie tlenowe, które są wolno żyjące w wodach słodkich, osadach i oceanach. Godne uwagi gatunki to Spirochaeta plicatilis z siarczkowych środowisk słodkowodnych i morskich. Cristispira to rodzaj krętków, które występują w krystalicznym stylu wielu małży, takich jak małże, małże i ostrygi. Rodzaj Treponema obejmuje krętki beztlenowe lub mikroaerofilne, które są komensalami lub patogenami ludzi i zwierząt, takie jak Treponema denticola, powszechne w ludzkiej jamie ustnej. Wiele gatunków z rodzaju Borrelia jest chorobotwórczych. Na przykład Borrelia burgdorferi powoduje boreliozę, która jest przenoszona przez kleszcze. Rodzaje Leptospira i Leptonema są ściśle aerobowymi krętkami, które utleniają długołańcuchowe kwasy tłuszczowe, takie jak kwas oleinowy, z tkanek gospodarza lub środowiska, aby wspomóc ich wzrost. Leptospira interrogans jest pasożytniczy u ludzi i powoduje leptospirozę.

typ bakterii: spirochetes

Bacterial Phylum Spirochaetes

Kr&#281;tki, unikalne bakterie nale&#380;&#261;ce do typu Spirochaetes, s&#261; gram-ujemne, ruchliwe, ciasno skr&#281;cone, smuk&#322;e i elastyczne. Zamieszkuj&#261; osady wodne oraz organizmy zwierz&#281;ce, a niekt&#243;re gatunki wywo&#322;uj&#261; choroby, takie jak ki&#322;a. Kr&#281;tki klasyfikuje si&#281; do o&#347;miu rodzaj&#243;w na podstawie siedliska, patogenno&#347;ci, filogenezy oraz cech morfologicznych.
Ich charakterystyczna ruchliwo&#347;&#263; wynika z obecno&#347;ci endoflagelli zlokalizowanych w przestrzeni peryplazmatycznej kom&#243;rki. Endoflagelle zakotwiczone s&#261; na biegunach kom&#243;rki i rozci&#261;gaj&#261; si&#281; na jej d&#322;ugo&#347;ci, otoczone elastyczn&#261; pochewk&#261; zewn&#281;trzn&#261;. Obr&#243;t endoflagelli powoduje skr&#281;t kom&#243;rki, umo&#380;liwiaj&#261;c jej poruszanie si&#281; ruchem przypominaj&#261;cym korkoci&#261;g, co u&#322;atwia penetracj&#281; przez lepkie substancje lub tkanki. Kr&#281;tki s&#261; cz&#281;sto mylone ze &#347;rubowcami, spiralnymi, pa&#322;eczkowatymi kom&#243;rkami z biegunow&#261; wici&#261;. W przeciwie&#324;stwie do kr&#281;tk&#243;w, &#347;rubowce nie posiadaj&#261; pochewki zewn&#281;trznej, endoflagelli ani nie wykazuj&#261; ruchu korkoci&#261;gowego. &#346;rubowce s&#261; sztywniejsze i wi&#281;ksze, podczas gdy kr&#281;tki s&#261; cienkie (oko&#322;o 0,5 &#956;m) i wysoce elastyczne.
Rodzaj Spirochaeta obejmuje wolno &#380;yj&#261;ce, beztlenowe i fakultatywnie tlenowe kr&#281;tki wyst&#281;puj&#261;ce w wodach s&#322;odkich, osadach i oceanach. Spirochaeta plicatilis wyst&#281;puje w &#347;rodowiskach s&#322;odkowodnych i morskich bogatych w siarkowod&#243;r, posiada p&#281;ki endoflagelli otaczaj&#261;ce jej spiralnie skr&#281;cony cylinder protoplazmatyczny. Spirochaeta stenostrepta, obligatoryjny beztlenowiec zasiedlaj&#261;cy osady bogate w H_2S, fermentuje cukry do etanolu, octanu, mleczanu, CO_2 i H_2.
Rodzaj Cristispira, charakterystyczny dla stylika krystalicznego mi&#281;czak&#243;w takich jak ma&#322;&#380;e i ostrygi, uczestniczy w procesie trawienia w ich przewodach pokarmowych. Wyst&#281;puje u mi&#281;czak&#243;w s&#322;odkowodnych i morskich, nie zosta&#322; jednak wyhodowany w warunkach laboratoryjnych, a jego szczeg&#243;lne przystosowanie do tego &#347;rodowiska pozostaje niejasne.
Beztlenowe lub mikroaerofilne kr&#281;tki z rodzaju Treponema s&#261; komensalami lub patogenami ludzi i zwierz&#261;t. Treponema pallidum, czynnik etiologiczny ki&#322;y, jest niezwykle cienki (0,2 &#956;m) i ma sp&#322;aszczony, falisty kszta&#322;t. W diagnostyce zmian ki&#322;owych powszechnie stosuje si&#281; mikroskopi&#281; w ciemnym polu.
Inne gatunki to m.in. T. denticola, wyst&#281;puj&#261;cy w jamie ustnej cz&#322;owieka i zwi&#261;zany z chorobami dzi&#261;se&#322;. Fermentuje aminokwasy do octanu, CO_2, NH_3 i H_2S. T. saccharophilum wyst&#281;puje w &#380;waczu prze&#380;uwaczy, fermentuj&#261;c polisacharydy ro&#347;linne, natomiast T. primitia i T. azotonutricium zasiedlaj&#261; przew&#243;d pokarmowy termit&#243;w, gdzie uczestnicz&#261; w fermentacji celulozy, acetogenezie i wi&#261;zaniu azotu.
Rodzaj Borrelia obejmuje patogeny takie jak B. burgdorferi, wywo&#322;uj&#261;c&#261; borelioz&#281; przenoszon&#261; przez kleszcze. B. burgdorferi, unikatowa ze wzgl&#281;du na chromosom liniowy, infekuje ludzi i zwierz&#281;ta. Inne gatunki Borrelia wywo&#322;uj&#261; choroby u zwierz&#261;t hodowlanych i ptak&#243;w, zazwyczaj przenoszone przez uk&#261;szenia kleszczy.
Rodzaje Leptospira i Leptonema obejmuj&#261; &#347;cis&#322;e tlenowe kr&#281;tki, kt&#243;re do wzrostu utleniaj&#261; d&#322;ugo&#322;a&#324;cuchowe kwasy t&#322;uszczowe, takie jak kwas oleinowy. Gatunki Leptospira s&#261; cienkie, drobno skr&#281;cone i zazwyczaj zako&#324;czone haczykowato zagi&#281;tymi ko&#324;cami. W sk&#322;ad tej grupy wchodz&#261; zar&#243;wno formy wolno &#380;yj&#261;ce (L. biflexa), jak i paso&#380;ytnicze (L. interrogans).
Szczepy L. interrogans zaka&#380;aj&#261; ludzi i zwierz&#281;ta, przy czym g&#322;&#243;wnymi gospodarzami s&#261; gryzonie, cho&#263; nosicielami mog&#261; by&#263; r&#243;wnie&#380; psy i &#347;winie. U ludzi leptospiroza jest najcz&#281;stszym schorzeniem wywo&#322;ywanym przez Leptospira i prowadzi do uszkodzenia nerek i w&#261;troby, zapalenia nerek, &#380;&#243;&#322;taczki, a w ci&#281;&#380;kich przypadkach do niewydolno&#347;ci nerek lub &#347;mierci. Bakterie przedostaj&#261; si&#281; do organizmu przez b&#322;ony &#347;luzowe lub uszkodzon&#261; sk&#243;r&#281; podczas kontaktu z zaka&#380;onymi zwierz&#281;tami. Zwierz&#281;ta domowe, takie jak psy, s&#261; szczepione przeciw leptospirozie w ramach skojarzonej szczepionki przeciwko nos&#243;wce, leptospirozie i zapaleniu w&#261;troby.

Typ bakterii: Spirochetes

Kr&#281;tki, unikalne bakterie nale&#380;&#261;ce do typu Spirochaetes, s&#261; gram-ujemne, ruchliwe, ciasno skr&#281;cone, smuk&#322;e i elastyczne. ...

Education

JoVE Core

Microbiology

Mikrobiologia

Unit

Jednostka

Microbial Diversity

Różnorodność mikrobiologiczna

KEY TERMS AND CONCEPTS

KLUCZOWE TERMINY I POJĘCIA

spirochete shape, motion, and disease

Spirochetes are a group of gram-negative bacteria with a thin, flexible, tightly coiled shape. They live in aquatic sediments and in animals. Some species are harmless, while others cause diseases such as syphilis and Lyme disease.

A key feature of spirochetes is their movement. They use endoflagella, which are flagella located inside the periplasm, the space under the outer layer of the cell. These endoflagella attach at the cell poles and run along the length of the bacterium inside a flexible outer sheath. When they rotate, they twist the cell into a corkscrew-like motion that helps it move through thick liquids and tissues.

Spirochetes are often confused with spirilla. Spirilla are helical or rod-shaped cells with polar flagella, but they lack an outer sheath and endoflagella. They are also more rigid and larger. Spirochetes are much thinner, about 0.5 micrometers wide, and they bend easily.

Scientists divide spirochetes into eight genera based on habitat, pathogenicity, phylogeny, and other traits. The genus Spirochaeta includes free-living species that can live without oxygen or with little oxygen. These bacteria are found in freshwater, sediments, and oceans. Spirochaeta plicatilis lives in sulfidic freshwater and marine habitats, and its endoflagella form bundles around the coiled cell. Spirochaeta stenostrepta is an obligate anaerobe in H2S-rich muds. It ferments sugars and produces ethanol, acetate, lactate, CO2, and H2.

Cristispira is another genus. It lives in the crystalline style of mollusks such as clams and oysters and helps with food processing in their digestive tracts. It is found in both freshwater and marine mollusks, but it has not been cultured, so its special adaptation to this habitat is still unclear.

Treponema species are anaerobic or microaerophilic spirochetes that live as commensals or pathogens in humans and animals. Treponema pallidum causes syphilis and is extremely thin, about 0.2 micrometers wide, with a flat, wavy shape. Dark-field microscopy is often used to detect it in syphilitic lesions. Other species include T. denticola in the human mouth, where it is linked to gum disease, T. saccharophilum in the rumen of ruminants, and T. primitia and T. azotonutricium in termite guts, where they help with cellulose fermentation, acetogenesis, and nitrogen fixation.

The genus Borrelia includes important pathogens such as B. burgdorferi, which causes Lyme disease and spreads through tick bites. This species is unusual because it has a linear chromosome. Other Borrelia species cause disease in livestock and birds and are also transmitted by ticks.

Leptospira and Leptonema are strictly aerobic spirochetes that grow by oxidizing long-chain fatty acids such as oleic acid. Leptospira species are thin, finely coiled, and often hooked at both ends. The group includes free-living L. biflexa and parasitic L. interrogans. Rodents are the main hosts for L. interrogans, although dogs and pigs can also carry it. In humans, leptospirosis can damage the kidneys and liver and may cause nephritis, jaundice, renal failure, or death. The bacteria enter through mucous membranes or skin breaks after contact with infected animals. Dogs are vaccinated against leptospirosis with a combined distemper–leptospira–hepatitis vaccine.

Spirochete Shape, Motion, and Disease

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Ribosomal RNA, or rRNA, changed how scientists classify life. Sequence analysis showed three major groups of cells: eukaryotes, bacteria, and archaea. In 1978, Carl R. Woese proposed domains as a taxonomic level above kingdoms to separate these groups. Woese also showed that archaea and bacteria are not the same, even though they can look similar. The three domains differ in rRNA, membrane lipid structure, transfer RNA, and sensitivity to antibiotics. These differences helped scientists build...

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Verrucomicrobiota Cell Structure and Traits

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bacterial phylum spirochaetes

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Heat-Loving Bacteria and Their Enzymes

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diversity of protists i

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diversity of protists ii

Alveolates: Ciliates, Dinoflagellates, Apicomplexans

Alveolates are protists with tiny sacs called alveoli beneath the cell membrane. These sacs may help control water balance by limiting how much water moves in and out of the cell. In dinoflagellates, alveoli may also act like armor plates. The three main alveolate groups are ciliates, dinoflagellates, and apicomplexans. Ciliates move with cilia, which are short hair-like structures that can cover the whole cell or appear in rows or tufts. One well-known ciliate is Paramecium, which uses cilia...

diversity of protists iii

Rhizaria: Pseudopods, Tests, and Skeletons

Rhizaria are unicellular protists with threadlike pseudopodia, which are thin cytoplasmic extensions used for movement and feeding. Their amoeboid shape once caused taxonomic confusion, but molecular phylogenetics has since shown where they fit on the evolutionary tree. This group includes Chlorarachniophyta, Radiolaria, and Foraminifera, and each lineage has adapted to a different ecological niche and metabolic strategy. Chlorarachniophyta are unicellular phototrophic protists found in marine...

diversity of protists iv

Amoebozoa: Movement and Life Cycles

Amoebozoa are a diverse group of terrestrial and aquatic protists. They move and feed with lobe-shaped pseudopodia. This feature sets them apart from Rhizaria, which have threadlike pseudopodia. The group includes gymnamoebas, entamoebas, and the plasmodial and cellular slime molds. Phylogenetic evidence also shows that Amoebozoa split from a lineage that later gave rise to fungi and animals. Gymnamoebas are free-living protists that live in water and soil. They move by amoeboid movement,...

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Explore spirochete structure, corkscrew motility, and major genera like Treponema, Borrelia, and Leptospira, plus diseases such as syphilis and Lyme disease.

Spirochete Shape, Motion, and Disease | JoVE K12

JoVE Core Microbiology provides an engaging introduction to the microbial world and its influence on health, industry, and the environment. This comprehensive collection covers key concepts such as microbial structure, metabolism, genetics, and ecology. It introduces essential laboratory techniques and microscopy methods through visually engaging animations. Corresponding scientist-in-action videos bridge classroom concepts with real-world research and applications.

microbiology

Spirochete Shape, Motion, and Disease

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