EMB agar na MacConkey agar: guhitamo no gusobanura media

Umunyeshuri asiga icyitegererezo kimwe cy’amazi ku masahani abiri. Kuri umwe, hagaragara koloni zijimye zifite urumuri rw’icyatsi rumeze nk’icyuma. Ku wundi, hagaragara koloni z’umutuku werurutse zizengurutswe n’agace k’igihu. Amasahani yombi yatewe icyitegererezo kivuye mu muyoboro umwe, ashyirwa mu bushyuhe hamwe, kandi asomwa ku isaha imwe. Umunyeshuri abaza isahani iri ukuri.

Amasahani yombi ari ukuri. Asubiza ibibazo bitandukanye. Urujijo ruturuka ku gufata izi media zombi nk’aho zasimburana mu gushakisha bagiteri zo mu mara. Zihuje intego yo gutoranya ibinyabuzima byo mu mara bya Gram negative no gutandukanya abahindura lactose n’abatayihindura, ariko iyo ntego ziyigeraho zikoresheje chimie itandukanye n’uburyo butandukanye bwo gusoma ibigaragara. Iyo umaze gusobanukirwa izi ngingo ebyiri z’ibanze, guhitamo isahani no gusoma koloni biba ibintu bisanzwe.

Igisubizo kigufi

EMB agar ikoresha amabara abiri, eosin Y na methylene blue, akora imirimo ibiri icyarimwe: abuza cyane imikurire ya Gram positive kandi akagwa agafatira hafi y’abakora aside nyinshi, bigatuma haboneka koloni zijimye, kandi ku buryo busanzwe Escherichia coli ikagaragaza urumuri rw’icyatsi rumeze nk’icyuma. MacConkey agar itandukanya iyo mirimo: bile salts hamwe na crystal violet bibuza Gram positives, lactose igatanga ikigaburira fermentation, naho neutral red ikagaragaza aside binyuze muri koloni z’umutuku cyangwa umutuku wijimye. Iyo intego ari ukwerekana E. coli mu buryo bugaragara bwo kuyikeka mbere yo kuyemeza, EMB iba ifite akamaro. Iyo intego ari ugutandukanya mu buryo bworoshye abahindura lactose b’umutuku n’abatayihindura badafite ibara, cyane cyane mu mikorere ikoresha umwanda cyangwa inkari, MacConkey akenshi ni yo yoroshye gusoma. Nta sahani n’imwe ishobora kumenya ubwoko bw’ikinyabuzima ishingiye ku ibara ryonyine.

EMB: amabara atoranya kandi akanatanga ikimenyetso icyarimwe

Igitekerezo cya EMB gihuza itoranya n’itangwa ry’ikimenyetso mu molekile zimwe. Porotokole ya ASM ya eosin methylene blue agar isobanura EMB nka medium itoranya kandi ikanatanga itandukaniro, aho amabara yombi abuza ibinyabuzima byinshi bya Gram positive mu gihe fermentation ya lactose itera amabara kwinjira no kugwa agafatira. Formulation isanzwe ya Levine iba irimo peptone, lactose, phosphate, eosin Y, methylene blue, na agar, nk’uko biri ku rutonde muri uburyo bwa FDA BAM bwa Levine EMB agar. Menya ko formulations za kera za EMB rimwe na rimwe zongeragamo sucrose hamwe na lactose, mu gihe Levine EMB irimo lactose ariko nta sucrose, bityo wandike formulation laboratwari yawe ikoresha.

Gusoma EMB ni ugusoma uko amabara yitwara. Fermentation ikomeye ya lactose ikora aside ihagije kugira ngo itere amabara kugwa no gufatira cyane, bigaha E. coli hagati hijimye h’ubururu-bwirabura kandi, mu buryo busanzwe, urumuri rw’icyatsi rumeze nk’icyuma iyo rurebwe mu rumuri rugaruka. Abahindura lactose buhoro nka Enterobacter na Klebsiella akenshi bakura nk’ikoloni z’umutuku kugeza ku ibara ry’umuhemba, zifite imiterere ya mucoid ariko nta rumuri nk’urwo. Abatayihindura nka Salmonella, Shigella, na Proteus muri rusange bakura nk’ikoloni zidafite ibara cyangwa zibonerana, kuko badakora igitero gikomeye cya aside gituma amabara agwa agafatira. Gram positives akenshi zirahagarikwa, nubwo urugero rw’iryo hagarikwa rutandukanye bitewe na strain n’igicuruzwa. Chimie yuzuye y’itegurwa ry’amabara, harimo impamvu methylene blue yitwara nk’irangi rya cationic, ikwiye gusobanurwa mu kindi kiganiro ku formulations z’amabara, naho amakuru rusange ya microscopy ari muri atlasi y’uburyo bwo gusiga amabara. Iyi nyandiko iguma ku guhitamo amasahani no gusoma ibisubizo.

Ishusho iri hejuru ni iy’icyitegererezo. Yerekana uburyo bwo kureba ugomba kwitega: koloni zijimye zifite urumuri, ubwoko bwa mucoid bw’umutuku, n’ubwoko bwijimye gake kuri EMB, ugereranyije n’ubwoko bw’umutuku n’ubwijimye gake kuri MacConkey. Yikoreshe mu kwiga uwo murongo w’ibigaragara, hanyuma wemeze buri mwanzuro ukoresheje controls zafotowe n’amabwiriza y’igicuruzwa cya medium nyacyo kiri ku meza yawe.

MacConkey: imirimo itandukanye, itegeko ryoroshye ryo kureba

Igitekerezo cya MacConkey giha buri kintu umurimo wacyo. Porotokole ya ASM ya MacConkey agar itanga uburyo bumwe bwo kuyifata nka medium itoranya kandi itandukanya, naho uburyo bwa FDA BAM bwa MacConkey agar bukerekana ibice bikora: peptones, lactose, bile salts, salt, neutral red, crystal violet, na agar. Bile salts hamwe na crystal violet bitoranya birwanya Gram positives. Lactose itanga substrate ya fermentation. Neutral red ikora nk’ikimenyetso cya pH, igahinduka umutuku kugeza ku mutuku wijimye aho aside ikorewe, rimwe na rimwe hakabaho bile yagushije agafatira hafi y’abahindura cyane.

Itegeko ryo gusoma ryoroshye nkana: umutuku bisobanura umuhindura lactose, naho nta bara cyangwa ibara ryoroshye bisobanura utayihindura. E. coli igaragara ari umutuku kugeza ku mutuku wijimye, akenshi ifite halo ya bile precipitate. Klebsiella na Enterobacter zigaragara ari umutuku kandi akenshi zifite imiterere ya mucoid kubera capsules zazo. Salmonella, Shigella, Proteus, n’izindi nkoni nyinshi za Gram negative zigaragara zidafite ibara. Hari n’indi nyungu ifite akamaro muri laboratwari zo kwigishirizamo: bile salts muri rusange zigabanya swarming ya Proteus, bityo kubona koloni zitandukanye bikoroha kuri MacConkey kurusha kuri media zidatoranya, nubwo iryo hagarikwa ridahora ryuzuye kandi hakabaho ubundi buryo butarimo salt igihe kugenzura swarming ari byo by’ingenzi.

Impamvu ya molekile ituma aya mabara yitwara gutya ishingiye ku muriro w’amashanyarazi n’imiterere. Methylene blue ni irangi rya cationic phenothiazine rifite imiterere n’ibiranga bisobanura uburyo rikunda ubuso bwa bagiteri burimo aside, ari na bwo buryo bukora igihe rigwa rigafatira mu bice birimo aside kuri EMB.

Kugereranya mu buryo bwihuse

Soma imbonerahamwe nk’uburyo bwo gufata icyemezo. Iyo umwitozo usaba abanyeshuri kubona urwego rw’imbaraga za fermentation rufite iherezo rimwe rigaragara cyane, EMB irabyerekana. Iyo umwitozo usaba gutandukanya vuba mu byiciro bibiri mbere yo kwemeza hakoreshejwe biochemical tests, MacConkey irabyerekana.

Ni iyihe medium ikoreshwa ku cyitegererezo ikihe

Ku myitozo y’amazi igamije kumenya by’agateganyo fecal coliform cyangwa E. coli, EMB irakurura kubera ko urumuri rwayo rwihariye ruboneka neza. MacConkey na yo ikorana na Gram negatives zo mu mara kandi yagiye ikoreshwa mu mateka mu gupima amazi, ariko nta sahani n’imwe muri zo isimbura uburyo bwemewe n’amabwiriza yo gupima amazi, bushobora gusaba media nka modified mTEC cyangwa MI bitewe n’ikizamini. Reba uburyo laboratwari yawe isabwa gukurikiza.

Ku gutandukanya abahindura n’abatayihindura mu byitegererezo bisa n’umwanda, MacConkey muri rusange ni yo ifite akamaro kurusha indi. Mu mikorere isanzwe ku mwanda yo gushaka Salmonella cyangwa Shigella, akenshi hongerwamo media zo mu mara zitoranya cyane nka XLD cyangwa Hektoen enteric aho kwishingikiriza kuri MacConkey yonyine.

Ku myitozo y’inkari yigana imikorere ya clinical laboratory, huza MacConkey na blood agar. MacConkey itanga itandukaniro rya mbere rya Gram negative, mu gihe blood agar ituma ibinyabuzima MacConkey ihagarika na byo bikura. Uku guhuza ni ibisanzwe mu bisobanuro bya clinical workflow yo gutegura urine culture.

Ku kwigisha igitekerezo nyir’izina, koresha zombi. EMB yigisha ko imbaraga za fermentation zifite akamaro kandi ko molekile imwe ishobora gukora imirimo ibiri. MacConkey yigisha modular design: selector, substrate, na reporter bitandukanyijwe. Abanyeshuri basiga E. coli izwi, Klebsiella aerogenes izwi, na Salmonella izwi ku mpande zegeranye kuri media zombi, akenshi ntibongera kuvanga uburyo izi media zombi zikora.

Amakosa yo gusoma ahora agaruka buri gihembwe

Ikosa rikunze kubaho cyane ni ukumenya ikinyabuzima ukurikije ibara ryonyine. Umutuku kuri MacConkey ushobora kuba E. coli, Klebsiella, Enterobacter, cyangwa undi uhindura lactose. Kutagira ibara bishobora kuba Salmonella, Shigella, Proteus, Pseudomonas, cyangwa undi utayihindura. Ibara ni phenotype yo gushakisha ibimenyetso iyobora ku bindi bizamini byo kwemeza nka Gram stain, oxidase, biochemical panels, cyangwa kumenya ikinyabuzima hakoreshejwe instrument, si izina rya species.

Ikosa rya kabiri ni guha uburemere burenze urugero kubura k’urumuri. Koloni zimwe za E. coli nyazo, cyane cyane iziri zonyine, zigaragaza urumuri rw’icyuma ruke cyangwa ntirugaragare na gato kuri EMB. Kubura urumuri ntibikuraho E. coli, kandi kubaho kwarwo ntibiyemeza. Fata urwo rumuri nk’ikimenyetso cyo gukeka mbere yo kwemeza.

Ikosa rya gatatu ni ukugereranya amasahani afite imyaka itandukanye. Abahindura lactose batinda bashobora guhinduka umutuku kuri MacConkey nyuma y’igihe kirekire cya incubation, bigatuma itandukaniro risobanutse hagati y’abahindura n’abatayihindura ritakaza umurongo. Soma ku isaha yagenwe na laboratwari kandi wandike igihe cya incubation hamwe n’igisubizo.

Ikosa rya kane ni ugusoma imikurire ivanze nk’ikinyabuzima kimwe. Koloni y’umutuku iri iruhande rw’idafite ibara igaragaza phenotypes ebyiri, si phenotype yo hagati. Hitamo koloni zatandukanye neza kandi ukore kuri buri morphotype ukwawo. Imiterere ya mucoid na yo izana urujijo rusa: Klebsiella na Enterobacter zombi zishobora kugaragara nka mucoid, bityo capsule yonyine ntishobora kwemeza izina. Ikinyabuzima cyahoze cyigishwa nka Enterobacter aerogenes ubu gishyirwa mu cyiciro cya Klebsiella aerogenes, ari byo bisobanura impamvu imbonerahamwe za kera n’amazina mashya bishobora kugaragara nk’aho bidahuye.

Controls n’itegeko risoza

Koresha controls zafotowe cyangwa nshya buri gihe: E. coli ku reaction ikomeye ya fermentation, Klebsiella aerogenes ku fermentation ya mucoid idafite urumuri rusanzwe, strain ya Salmonella ku reaction y’utahindura udafite ibara, na Staphylococcus aureus kugira ngo wemeze ihagarikwa rya Gram positive ku gicuruzwa cyawe nyacyo. Huza nimero za strain n’ibipimo byo kwemera n’amabwiriza y’uruganda, kuko selectivity ihinduka bitewe n’ingano ya bile, crystal violet, n’amabara.

Ibuka interuro imwe uri ku meza ya laboratwari. EMB ikoresha amabara atoranya kandi akanatanga ikimenyetso, bikayihesha ikimenyetso cya E. coli kigaragara cyane ariko bikamusaba gusoma ibisobanuro byoroheje kurushaho. MacConkey itandukanya igikorwa cyo gutoranya n’icyo gutanga ikimenyetso, bikayihesha itandukaniro ryoroshye hagati y’umutuku n’ibara ryoroshye ariko ikagaragaza amakuru make ku mbaraga za fermentation. Hitamo medium ihuye n’ikibazo ushaka gusubiza, wemeze ibara ukoresheje ibizamini bikwiye, maze amasahani yombi areke guhangana atangire gukorana.