EMB agar poyerekeza ndi MacConkey agar: kusankha ndi kutanthauzira media

Wophunzira amaika streak ya water sample yomweyo pa ma plate awiri. Pa imodzi, pamamera ma colony akuda okhala ndi kuwala kobiriwira ngati chitsulo. Pa inayo, pamamera ma colony apinki owala okhala ndi halo yachifunga. Ma plate onse awiri anaikidwa inoculum kuchokera mu tube yomweyo, anaikidwa pa incubation mbali ndi mbali, ndipo anawerengedwa pa ola lomwelo. Wophunzirayo amafunsa kuti ndi plate iti yomwe ili yolondola.

Ma plate onse awiri ndi olondola. Amayankha mafunso osiyana. Kusokonezeka kumachitika chifukwa chotenga media ziwirizi ngati njira zofanana zowunikira mabakiteriya a m'matumbo. Zili ndi cholinga chofanana, chomwe ndi kusankha tizilombo ta Gram negative enteric ndi kusiyanitsa lactose fermenters ndi nonfermenters, koma zimakwaniritsa cholingacho pogwiritsa ntchito chemistry yosiyana komanso njira yosiyana yowonera zotsatira. Mukamvetsetsa mfundo ziwiri zomwe zili maziko ake, kusankha plate ndi kuwerenga colony kumakhala kosavuta.

Yankho lachidule

EMB agar imagwiritsa ntchito dyes ziwiri, eosin Y ndi methylene blue, zomwe zimagwira ntchito ziwiri nthawi imodzi: zimalepheretsa kukula kwa Gram positive ndipo zimapanga precipitate mozungulira tizilombo topanga acid kwambiri, zomwe zimapanga ma colony akuda, ndipo mwachizolowezi Escherichia coli imakhala ndi metallic green sheen. MacConkey agar imagawanitsa ntchitozi: bile salts kuphatikiza crystal violet zimalepheretsa Gram positives, lactose imathandiza fermentation, ndipo neutral red imasonyeza acid ngati ma colony apinki kapena ofiira. Ngati ntchito yake ndi kusonyeza E. coli mwamphamvu ngati chizindikiro choyambirira, EMB ndi yoyenera. Ngati ntchito yake ndi kusiyanitsa mosavuta ma lactose fermenters apinki ndi nonfermenters opanda mtundu, makamaka mu stool kapena urine workflows, MacConkey nthawi zambiri imakhala yosavuta kuwerenga. Palibe plate yomwe imazindikiritsa organism pogwiritsa ntchito mtundu wokha.

EMB: dyes zomwe zimasankha ndi kusonyeza nthawi imodzi

Mfundo ya EMB imaphatikiza kusankha ndi kusonyeza mu mamolekyu omwewo. ASM eosin methylene blue agar protocol imafotokoza EMB ngati selective komanso differential, pomwe dye pair imalepheretsa tizilombo tambiri ta Gram positive pamene lactose fermentation imachititsa dyes kulowa ndi kupanga precipitate. Standard Levine formulation imakhala ndi peptone, lactose, phosphate, eosin Y, methylene blue, ndi agar, monga zalembedwera mu FDA BAM method for Levine EMB agar. Dziwani kuti maphikidwe akale a EMB nthawi zina ankawonjezera sucrose pamodzi ndi lactose, pamene Levine EMB imakhala ndi lactose popanda sucrose, choncho lembani formulation yomwe laboratory yanu imagwiritsa ntchito.

Kuwerenga EMB kumatanthauza kuwerenga khalidwe la dye. Lactose fermentation yamphamvu imapanga acid yokwanira kuyambitsa dye precipitation yambiri, zomwe zimapatsa E. coli ma center ake akuda a blue-black ndipo, mu maonekedwe achizolowezi, metallic green sheen mukaiyang'ana ndi reflected light. Ma fermenter ofooka monga Enterobacter ndi Klebsiella nthawi zambiri amakula ngati ma colony apinki mpaka purple, a mucoid, opanda sheen imeneyo. Nonfermenters monga Salmonella, Shigella, ndi Proteus nthawi zambiri amakula ngati ma colony opanda mtundu kapena translucent chifukwa sapanga acid burst yomwe imachititsa dyes kupanga precipitate. Gram positives nthawi zambiri zimaletsedwa, ngakhale kuchuluka kwa suppression kumasiyana malinga ndi strain ndi product. Chemistry yonse yokonzekera dye, kuphatikizapo chifukwa chake methylene blue imakhala ngati cationic stain poyamba, ndi nkhani ina yokhudza dye formulations, ndipo microscopy context yonse ili mu atlas ya staining methods. Nkhaniyi ikungoyang'ana pa kusankha plate ndi kuwerenga.

Chithunzi chili pamwambachi ndi chofotokozera. Chimasonyeza njira yowonera yomwe muyenera kuyembekezera: ma colony akuda okhala ndi sheen, mitundu ya pinki ya mucoid, ndi mitundu yotuwa pa EMB, poyerekeza ndi mitundu ya pinki ndi yotuwa pa MacConkey. Gwiritsani ntchito kuti muphunzire pattern, kenako tsimikizirani kuwerenga kulikonse ndi photographed controls komanso product insert ya medium yeniyeni yomwe ili pa bench yanu.

MacConkey: ntchito zogawidwa, lamulo losavuta lowonera

Mfundo ya MacConkey imapatsa ingredient iliyonse ntchito yake payokha. ASM MacConkey agar protocol imafotokoza chimodzimodzi za selective ndi differential, ndipo FDA BAM method for MacConkey agar imalemba zigawo zomwe zimagwira ntchito: peptones, lactose, bile salts, salt, neutral red, crystal violet, ndi agar. Bile salts kuphatikiza crystal violet zimasankha motsutsana ndi Gram positives. Lactose imapereka substrate ya fermentation. Neutral red imagwira ntchito ngati pH reporter, kusanduka pinki mpaka kufiira pamene acid yapangidwa, ndipo nthawi zina pamakhala precipitated bile mozungulira ma fermenter amphamvu.

Lamulo lowerengera lapangidwa kuti likhale losavuta: pinki limatanthauza lactose fermenter, ndipo lopanda mtundu kapena lotuwa limatanthauza nonfermenter. E. coli imaoneka pinki mpaka yofiira, nthawi zambiri yokhala ndi halo ya bile precipitate. Klebsiella ndi Enterobacter zimaoneka pinki ndipo nthawi zambiri zimakhala mucoid chifukwa cha capsules zake. Salmonella, Shigella, Proteus, ndi ma rod ena ambiri a Gram negative amaoneka opanda mtundu. Pali phindu lina lofunika m'ma teaching labs: bile salts nthawi zambiri zimachepetsa Proteus swarming, kotero ma colony odzipatula amapezeka mosavuta pa MacConkey kuposa pa nonselective media, ngakhale suppression si yokwanira ndipo pali njira zopanda salt ngati kuletsa swarming ndiye cholinga chachikulu.

Chifukwa cha molecular chomwe dyes zimachitira motere chimachokera ku charge ndi structure. Methylene blue ndi cationic phenothiazine dye yomwe structure ndi properties zake zimafotokoza affinity yake ndi acidic bacterial surfaces, yomwe ndi affinity yomweyi yomwe imagwira ntchito ikamapanga precipitate m'madera a acid pa EMB.

Kuyerekezera mwachidule

Werengani tebulo ngati njira yopangira chisankho. Ngati exercise ikufuna ophunzira kuona kusiyanasiyana kwa fermentation strength yokhala ndi endpoint imodzi yowonekera kwambiri, EMB imasonyeza zimenezo. Ngati exercise ikufuna kusiyanitsa mwachangu magulu awiri asanachite biochemical confirmation, MacConkey imasonyeza zimenezo.

Medium iti pa sample iti

Pa water exercises zomwe cholinga chake ndi presumptive fecal coliform kapena kuzindikira E. coli, EMB ndi yosangalatsa chifukwa sheen yake imadziwika mosavuta. MacConkey imathanso kugwira ntchito ndi enteric Gram negatives ndipo yakhala ikugwiritsidwa ntchito pa water testing m'mbiri, koma palibe plate yomwe imalowa m'malo mwa regulatory water method, yomwe ingatchule media monga modified mTEC kapena MI malinga ndi test. Onani method yomwe laboratory yanu imayenera kutsatira.

Pa stool-style separation ya fermenters ndi nonfermenters, MacConkey nthawi zambiri imakhala yothandiza kwambiri mwa ziwirizi. Ntchito yeniyeni ya stool yokhudza Salmonella kapena Shigella nthawi zambiri imawonjezera selective enteric media monga XLD kapena Hektoen enteric m'malo modalira MacConkey yokha.

Pa urine-style teaching yomwe imatsanzira clinical workflow, gwirizanitsani MacConkey ndi blood agar. MacConkey imapereka kusiyanitsa koyambirira kwa Gram negative pamene blood agar imalola kukula kwa organisms zomwe MacConkey imalepheretsa. Pairing imeneyi ndi yofala mu clinical descriptions za urine culture setup.

Pa kuphunzitsa mfundo zokha, gwiritsani ntchito zonse. EMB imaphunzitsa kuti fermentation strength ndi yofunika komanso kuti molecule imodzi ingagwire ntchito ziwiri. MacConkey imaphunzitsa modular design: selector, substrate, ndi reporter zimasungidwa zosiyana. Ophunzira omwe amaika streak ya E. coli yodziwika, Klebsiella aerogenes yodziwika, ndi Salmonella yodziwika mbali ndi mbali pa media zonse ziwiri nthawi zambiri sasokonezanso njira ziwirizi.

Zolakwika powerenga zomwe zimabwereza term iliyonse

Cholakwika chofala kwambiri ndi kuzindikiritsa organism ndi mtundu wokha. Pinki pa MacConkey ikhoza kukhala E. coli, Klebsiella, Enterobacter, kapena fermenter ina. Yopanda mtundu ikhoza kukhala Salmonella, Shigella, Proteus, Pseudomonas, kapena nonfermenter ina. Mtundu ndi screening phenotype yomwe imatsogolera confirmatory work monga Gram stain, oxidase, biochemical panels, kapena instrument identification, osati dzina la species.

Cholakwika chachiwiri ndi kutanthauzira mopitirira muyeso kusapezeka kwa sheen. Ma colony ena enieni a E. coli, makamaka odzipatula, amapanga metallic sheen yochepa kapena palibe. Kusapezeka kwa sheen sikuchotsa E. coli, ndipo kupezeka kwa sheen sikutsimikizira. Tengani sheen ngati chizindikiro choyambirira chokha.

Cholakwika chachitatu ndi kuyerekezera ma plate a zaka zosiyana. Delayed lactose fermenters angasanduke pinki pa MacConkey pambuyo pa incubation yaitali, zomwe zimasokoneza kusiyanitsa koyera kwa fermenter ndi nonfermenter. Werengani pa ola lomwe laboratory yatchula ndipo lembani incubation time limodzi ndi result.

Cholakwika chachinayi ndi kuwerenga mixed growth ngati organism imodzi. Colony yapinki pafupi ndi colony yopanda mtundu imasonyeza phenotypes ziwiri, osati phenotype yapakati. Sankhani ma colony odzipatula bwino ndipo gwiritsani ntchito morphotype iliyonse payokha. Mucoid texture imabweretsanso msampha wofanana: Klebsiella ndi Enterobacter zonse zingawoneke mucoid, choncho capsule yokha siyitsimikizira dzina. Organism yomwe kale inkaphunzitsidwa ngati Enterobacter aerogenes tsopano imayikidwa m'gulu la Klebsiella aerogenes, zomwe zimafotokoza chifukwa chake ma chart akale ndi ma label atsopano amaoneka ngati sakugwirizana.

Controls ndi lamulo lomaliza

Gwiritsani ntchito photographed kapena fresh controls pa session iliyonse: E. coli pa strong fermenter reaction, Klebsiella aerogenes pa mucoid fermentation popanda classic sheen, Salmonella strain pa colorless nonfermenter reaction, ndi Staphylococcus aureus kuti mutsimikizire Gram positive suppression pa product yanu yeniyeni. Fananizani strain numbers ndi acceptance criteria ndi manufacturer insert, chifukwa selectivity imasintha malinga ndi bile, crystal violet, ndi dye content.

Kumbukirani sentence imodzi pa bench. EMB imagwiritsa ntchito dyes zomwe zonse zimasankha ndi kusonyeza, zomwe zimapereka E. coli signal yooneka kwambiri koma zimafuna kuwerenga mosamala kwambiri. MacConkey imasiyanitsa ntchito yosankha ndi yosonyeza, zomwe zimapereka kusiyanitsa kosavuta kwa pinki ndi yotuwa koma zimapereka fermentation detail yochepa. Sankhani medium yomwe mfundo yake ikugwirizana ndi funso, tsimikizirani mtundu ndi mayeso oyenera, ndipo ma plate awiriwa amasiya kupikisana n'kuyamba kugwirizana.