{"id":12086,"date":"2017-04-20T11:03:19","date_gmt":"2017-04-20T11:03:19","guid":{"rendered":"http:\/\/revoscience.com\/en\/?p=12086"},"modified":"2017-04-20T11:03:19","modified_gmt":"2017-04-20T11:03:19","slug":"study-finds-amoeba-grazing-killing-bacteria-usually-protected-film","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/study-finds-amoeba-grazing-killing-bacteria-usually-protected-film\/","title":{"rendered":"Study finds amoeba \u201cgrazing,\u201d killing bacteria usually protected by film"},"content":{"rendered":"
\"\"
Tara Solger, a graduate student from Iran, works with Polysphondylium amoeba in the lab of Marcin Filutowicz, a professor of bacteriology at UW\u2013Madison. DAVID TENENBAUM<\/figcaption><\/figure>\n

Bacteria have developed an uncountable number of chemistries, lifestyles, attacks and defenses through 2.5 billion years of evolution. One of the most impressive defenses is biofilm \u2013 a community of bacteria enmeshed in a matrix that protects against single-celled predators and antibiotics \u2013 chemicals evolved by competitors through the course of evolution, including other bacteria and fungi.<\/span><\/p>\n

Now, a University of Wisconsin\u2013Madison professor of bacteriology has shown the first proof that a certain group of amoeba called dictyostelids can penetrate biofilms and eat the bacteria within. \u201cThis is the first demonstration that dicty are able to feed on biofilm-enmeshed bacteria,\u201d Marcin \u00a0Filutowicz says.<\/span><\/p>\n

In an article now online in the journal Protist, Filutowicz, first author Dean Sanders of the Wisconsin Institute for Discovery, and colleagues show time-lapse, microscopic movies proving the amoeba\u2019s voracious appetite for five species of bacteria. In the study, the researchers pitted four types of amoeba called<\/span> dictyostelium<\/a> (dictys) against biofilm-forming bacteria that harm plants or humans. The target bacteria included:<\/span><\/p>\n

-Pseudomonas aeruginosa, a common, multi-drug resistant bacteria that afflicts people who have, for example, burns or cystic fibrosis;<\/span><\/p>\n

-Pseudomonas syringae, pathogen of beans;<\/span><\/p>\n

-Klebsiella oxytoca, cause of colitis and sepsis; and<\/span><\/p>\n

-Erwinia amylovora, cause of fire blight in apples and pears.<\/span><\/p>\n

As expected, the results depended on the strain of dicty and species of bacteria; in several cases, the dictys completely obliterated a thriving biofilm containing millions of bacteria within a day or two. The study, Filutowicz says, \u201ccontains the first movies ever to show dicty cells moving into a biofilm and devouring the bacteria.\u201d<\/span><\/p>\n

Because they form a multi-cellular phase sometimes called a \u201cslug,\u201d dictys are sometimes called \u201csocial amoeba.\u201d<\/span><\/p>\n

Beyond the visual evidence, spore germination and the subsequent union of single-celled dictys into a multi-cellular \u201cslug\u201d both showed successful attacks against all four species of bacteria.<\/span><\/p>\n

\"\"
Mitchell Nitschke, a research specialist from Sussex, Wisconsin, examines amoeba on a new microscope in the Filutowicz lab. Dictys grow fast enough to be seen in real time. DAVID TENENBAUM<\/figcaption><\/figure>\n

Filutowicz became interested in dictys after discovering a neglected\u00a0 archive of about 1,800 strains amassed by Kenneth Raper, a bacteriology colleague who started collecting the soil-borne microbes around the world in the 1930s. \u201cRaper was the first to isolate dictys, but after he died, his life work was scattered around the department and neglected,\u201d Filutowicz says.<\/span><\/p>\n

Filutowicz was intrigued, but he knew very little about dictys. Then, the answer to his most fundamental question \u2014 \u201cHow do I grow them?\u201d triggered a mental chain reaction. He found that Raper and his followers were feeding and growing dictys in the lab using bacterial prey, but nobody had apparently pursued their real-world potential as microbe hunters. \u201cIf you grow them on E coli [a common resident of the human intestine], I quickly realized, because dictys are not pathogenic, we might use them as a biological weapon against bacteria.\u201d<\/span><\/p>\n

Having previously started Conjugon, a company devoted to developing benign bacteria to defeat pathogenic microbes,\u00a0 Filutowicz says he was \u201cattuned to biological approaches, which were \u00a0unheard \u00a0then, and so this idea fell on a very fertile mind.\u201d<\/span><\/p>\n

With bacteria becoming resistant to a growing number of antibiotics, that\u2019s welcome news, although using a living organism may add complexity to the task of getting regulatory approval.<\/span><\/p>\n

Since 2010, Filutowicz has learned a good deal about how dicty \u201cgraze\u201d upon bacteria, and which ones they prefer. \u201cWe looked at how these cells dismantle biofilms, trying to understand what physical, chemical and mechanical forces deconstruct the biofilms, and how the dictys move in 3-D space. These are phagocytes, and they behave much like our own immune cells,\u201d says Filutowicz.<\/span><\/p>\n

His collaborator,<\/span> Curtis Brandt<\/a>, a professor of ophthalmology and visual science \u00a0at UW\u2013Madison, has produced promising results suggesting that the organisms are harmless to rodents, and is preparing to use dictys to fight bacterial keratitis, an eye infection, first in rodents and then in humans, in research supported by the National Institutes of Health.<\/span><\/p>\n

\u201cThis medical application may not reach the clinic in my lifetime, but it has a lot of promise, and eventually we may be able to advance it in many other medical uses,\u201d Filutowicz says.<\/span><\/p>\n

In 2010,<\/span> Filutowicz<\/a> formed<\/span> Amoebagone<\/a>, to advance research into use of dictys, starting by trying to fight fire blight and other bacterial infections of fruit trees and vegetables; supported by the National Science Foundation.<\/span><\/p>\n

Between the far-off human medical potential, and the near-term use in agriculture, Filutowicz is delightedly pulling on the thread left by Ken Raper\u2019s beneficial microbes; licensed by the Wisconsin Alumni Research Foundation to AmoebaGone.<\/span><\/p>\n

\u201cTo make a discovery, it needs some level of naivet\u00e9,\u201d he says. \u201cIf you know too much, you immediately appreciate why things will not work, cannot work. Otherwise, if it was a good idea, people would have done it already. Colleagues said dictys behaved like human phagocytes, but they never mentioned harnessing them as biological controls. Every day I walk through the departmental hallway and read the inscription: \u201cDiscovery consists of seeing of what everybody has seen and thinking what nobody has thought. I was lucky enough to enter this as the foolish innocent.\u201d<\/span><\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Bacteria have developed an uncountable number of chemistries, lifestyles, attacks and defenses through 2.5 billion years of evolution. One of the most impressive defenses is biofilm \u2013 a community of bacteria enmeshed in a matrix that protects against single-celled predators and antibiotics \u2013 chemicals evolved by competitors through the course of evolution, including other bacteria […]<\/p>\n","protected":false},"author":6,"featured_media":12087,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16,17],"tags":[],"class_list":["post-12086","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-biology","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367-300x220.jpg",300,220,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",490,360,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",89,65,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",500,367,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",96,70,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2017\/04\/filutowicz-tara-500x367.jpg",150,110,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"Biology<\/a> Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/12086","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=12086"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/12086\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/12087"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=12086"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=12086"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=12086"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}