Ukufunda ukubukeka kwamakoloni e-E. coli namanye ku-agar ye-EMB

Umfundi usabalalisa isampula engaziwa ngemigqa ku-agar ye-eosin methylene blue, ayifukamele ubusuku bonke, bese ebuya athole ipuleti elinamakoloni amnyama acwebezela ngokuluhlaza. Okubhalwe encwadini yamanothi kuthi "I-E. coli, iqinisekisiwe." Lokho okubhaliwe kusho okungaphezu kwalokho okungasekelwa yipuleti. Ipuleti libonisa izici zokukhula nokuvutshelwa ngaphansi kwezimo ezithile. Ukuhlonza uhlobo lwegciwane kuyisiphetho esehlukile esidinga ubufakazi obuhlukile.

Lo mhlahlandlela ubheka imiphumela ye-agar ye-EMB njengomsebenzi wokuhumusha okubonwayo. Uchaza umqondo oyisisekelo, ubonise i-atlasi yamapuleti eyisibonelo enezilawuli, futhi uchaze izimo lapho isithombe esisencwadini yokufunda singadukisa khona.

Umqondo oyisisekelo wepuleti

I-agar ye-EMB iyakhetha futhi iyahlukanisa. Odayi i-eosin Y ne-methylene blue bacindezela amagciwane amaningi ane-Gram-positive, ngakho isiphakeli sivuna ukukhula kwamagciwane ane-Gram-negative. Odayi abafanayo baphinde basebenze njengezinkomba: lapho igciwane livutshela ushukela otholakalayo futhi likhiqiza i-asidi eyanele endaweni elizungezile, ikoloni limunca udayi omningi bese liba nsomi ngokumnyama kuya kokuluhlaza okwesibhakabhaka okusamnyama. Lapho ukukhiqizwa kwe-asidi kunamandla, ingaphezulu lekoloni lingabonisa ukucwebezela okuluhlaza okusansimbi okushintsha ngokwe-engeli yokubuka. Inqubo ye-ASM yamapuleti e-agar ye-eosin methylene blue ichaza lokhu kuhlanganiswa kokukhetha nokuhlukanisa futhi inikeza izithombe eziyizinkomba zokufundisa.

Kunemininingwane eyodwa ebalulekile ngaphambi kokufunda noma yimuphi umphumela: hlola ukuthi kusetshenziswa iyiphi ingxube. Ingxube endala ye-Holt Harris Teague iqukethe i-lactose kanye ne-sucrose, kanti i-Levine EMB iqukethe i-lactose kuphela. Igciwane elivutshela i-sucrose kodwa lingavutsheli i-lactose, njengezinhlobo eziningi ze-Serratia marcescens ezihlukanisiwe, lingabukeka ngokuhlukile kulezi zingxube ezimbili. Imibhalo yomkhiqizi yeziphakeli ze-EMB iwusho ngokucacile lo mehluko wezingxube. Bhala umkhiqizi nengxube encwadini yamanothi kanye nomphumela.

I-agar ye-EMB elungisiwe engakafakwa amagciwane ivamise ukuba nsundu ngokubomvu kuya konsomi ngokubomvu, ngezinye izikhathi ibe nomthunzi oluhlaza noma izinhlayiyana ezincane eziwumule. Lowo mbala wesiphakeli awukona ukukhula. Qhathanisa konke okufundayo nepuleti elingakafakwa amagciwane noma nokubukeka kokuqala okubhaliwe, bese ufunda ipuleti lokuqala ngemva kwamahora angaba ngu-18 kuya ku-24 okufukamela lapho kukhona umoya ku-35 kuya ku-37 C, ngaphandle uma inqubo yokufundisa isho okuhlukile. Ukufukamela isikhathi eside kungashintsha ukubukeka kokuvutshelwa.

Indlela yokubuka ipuleti

Sebenzisa izinhlobo ezimbili zokukhanya. Qala uhlole ipuleti ngokukhanya okubuyayo noma okuvela nge-engeli, bese ulitshekisa: ukucwebezela okusansimbi kushintsha ngokwe-engeli futhi kungavela noma kunyamalale ngokushintsha indlela obuka ngayo. Bese ulihlola ngokukhanya okudlula kulo ukuze uhlolisise umbala wamakoloni nezindawo ezimnyama phakathi kwawo. Sebenzisa amakoloni ahlukene kahle kwamanye, ngoba ukuminyana namakoloni aseduze kushintsha ukunqwabelana kwe-asidi endaweni futhi kunganciphisa noma kugqamise umbala. Iqoqo lezithombe ze-ASM likubonisa ngokuqondile lokhu: i-E. coli ekukhulisweni kwamagciwane axubile ingalahlekelwa ukucwebezela okulindelekile ngoba amagciwane ayizungezile ashintsha isimo se-asidi.

Faka izilawuli noma nini lapho umsebenzi ukuvumela. Iqoqo elivamile lokufundisa lihlanganisa i-E. coli ATCC 25922 ukuze libonise umbala oluhlaza okwesibhakabhaka osamnyama nokucwebezela okusansimbi, igciwane elingavutsheli njenge-Salmonella Typhimurium ATCC 14028 noma i-Pseudomonas aeruginosa ATCC 27853 ukuze libonise ukubukeka okungenambala, kanye negciwane eline-Gram-positive njenge-Enterococcus faecalis noma i-Staphylococcus aureus njengesilawuli sokuvinjelwa kokukhula, njengoba kubhalwe emathebuleni ajwayelekile okulawula ikhwalithi yeziphakeli ze-EMB. Uma isilawuli esilindeleke ukuba sicwebezele singacwebezele, qala usole ukufukamela, ukuminyana, noma ingxube ngaphambi kokusola isampula engaziwa.

I-atlasi yamapuleti ayizibonelo

Amapuleti angezansi ayimidwebo ekhiqiziwe, hhayi izithombe zamagciwane akhuliswe ngempela. Abonisa iphethini okufanele uyibheke, hhayi umthunzi oqondile wanoma yiluphi uhlobo olulodwa. Waqhathanise nezithombe eziyizinkomba ze-ASM kanye namapuleti angempela avela elabhorethri yokufundisa.

Ipuleti 1: I-Escherichia coli ku-agar ye-EMB, umvutsheli onamandla we-lactose

I-E. coli ku-agar ye-EMB ivamise ukuba nsomi ngokumnyama kuya kokuluhlaza okwesibhakabhaka okusamnyama, ngokuvamile ibe nendawo emnyama phakathi nokucwebezela okuluhlaza okusansimbi ngenxa yokukhiqizwa kwe-asidi okunamandla. Lokhu kucwebezela kuwuphawu oludumile abafundi abalufunayo, kodwa kubheke njengobufakazi obusekelayo kunokuba kube yincazelo yokuthi igciwane liyini. Amandla okucwebezela ayahluka ngohlobo lwegciwane, isikhathi sokufukamela, ukuminyana kwamakoloni, ne-engeli yokubuka. Ukungabikho kokucwebezela akusho ukuthi i-E. coli ayikho, futhi ikoloni elimnyama elingacwebezele lingakhomba kwabanye abavutsheli abaningana. Khetha ikoloni elihlukaniswe kahle ukuze wenze noma yimuphi umsebenzi olandelayo kunokuba ufunde engxenyeni eminyene.

Ipuleti 2: I-Klebsiella pneumoniae ku-agar ye-EMB, umvutsheli onjengamafinyila

I-Klebsiella pneumoniae ku-agar ye-EMB ivamise ukwakha amakoloni amakhulu, acwebezelayo, anjengamafinyila, anemithunzi esuka kopinki ngokunsomi kuya konsundu ngokunsomi, ngokuvamile abe nezindawo ezimnyama phakathi kodwa ngokuvamile angabi nokucwebezela okusansimbi okunamandla. Ukubukeka okufanayo kwenzeka kwabanye abavutsheli abahlobene nayo njenge-Enterobacter. Ukuthungwa okunjengamafinyila nobukhulu bekoloni kuyingxenye yokufunda: ikoloni elipinki elincane neliyisicaba linokubaluleka okuhlukile kwelikhulu eliphakeme njengedome nelinjengamafinyila. Njengaku-E. coli, ipuleti lisikisela izici zokuvutshelwa, futhi ukuhlonza uhlobo oluthile kudinga ukuqinisekiswa ngokuhlolwa kwamakhemikhali ezinto eziphilayo okuchazwe ngezansi.

Ipuleti 3: I-Salmonella ku-agar ye-EMB nabanye abangavutsheli, amakoloni angenambala

I-Salmonella ku-agar ye-EMB nabanye abahlobene nayo abangavutsheli i-lactose, kuhlanganise i-Shigella nezinhlobo eziningi ze-Pseudomonas ezihlukanisiwe, bavame ukukhula njengamakoloni angenambala, adlulisa ukukhanya, noma anombala wenhlaka ophaphathekile. Ezinye izingxube nezimo zinikeza umthunzi opinki ongabonakali kakhulu, ngakho ikoloni elipinki ngokuphaphathekile alisho ngokuzenzakalela ukuthi liyavutshela. I-EMB ayihlukanisi i-Salmonella ne-Shigella noma nabanye abangavutsheli; lowo mehluko utholakala ekuhlolweni okulandelayo. Qaphela futhi ukuthi kuye kwabhalwa ngezinhlobo ze-Salmonella ezivutshela i-lactose ezinamakoloni acwebezela njengensimbi afana nawe-E. coli, okuyisizathu esengeziwe sokuthi ipuleti elilodwa alikwazi ukunikeza isiphetho esiqinisekile.

Ipuleti 4: I-Serratia marcescens nogibe lwengxube

I-Serratia marcescens inesigaba sayo ngoba abafundi bavame ukulindela amakoloni abomvu bese befunda ipuleti ngokungafanele. Izinhlobo eziningi ezihlukaniswe kumasampula asemtholampilo azivutsheli i-lactose, ngakho ku-Levine EMB zivame ukubonakala ziphaphathekile noma zinombala obuthakathaka. Ngenxa yokuthi izinhlobo eziningi ezihlukanisiwe zivutshela i-sucrose, ingxube equkethe i-sucrose inganikeza ukusabela okumnyama kakhulu noma okuhlobene kakhulu ne-asidi. Ungalindeli futhi umbala obomvu ojwayelekile we-prodigiosin ku-35 kuya ku-37 C; ukukhiqizwa kwalowo mbala akuthembekile ezingeni lokushisa lomshini wokufukamela. Lapho inqubo ikhuluma nge-Serratia marcescens ku-agar ye-EMB, hlola ukuthi inkulumo ithatha ukuthi kusetshenziswa yiphi ingxube. Ukubuyekezwa kwezinqubo zemetabolism ze-Serratia kufingqa iphethini yokungavutsheli i-lactose nokuvutshela i-sucrose okuguquguqukayo eyimbangela yalolu gibe.

Ipuleti 5: izilawuli namagciwane avinjelwe ukukhula

Amagciwane ane-Gram-positive njenge-Staphylococcus, i-Enterococcus, i-Streptococcus, ne-Bacillus ngokuvamile ayavinjelwa noma ukukhula kwawo kucindezelwa kakhulu ku-agar ye-EMB, nakuba ukuvinjelwa kungaphelele kuzo zonke izinhlobo. Iqoqo lezilawuli lenza ukufundwa kwemiphumela kuthembeke: isilawuli se-E. coli kufanele sibonise ukukhula okuhle okunombala oluhlaza okwesibhakabhaka osamnyama nokucwebezela, isilawuli segciwane elingavutsheli kufanele sibonise ukukhula okungenambala, kanti isilawuli sokuvinjelwa kufanele sibonise ukukhula okuncane noma kungakhuli nhlobo. Uma isilawuli sokuvinjelwa sikhula kahle, isinyathelo sokukhetha sehlulekile futhi konke okunye okufundwayo kulelo qoqo kuyasolisa. Izindlela zokudaya ziphendula umbuzo ohlukile kulowo ophendulwa iziphakeli zokukhulisa amagciwane; ngohlangothi lokudaya amaslayidi elabhorethri, bheka i-atlasi yokudaya nge-methylene blue.

Ukuqhathanisa okunemikhawulo

Imisho emithathu ifingqa ukubukeka okudukisayo. Ukuba mnyama akusho i-E. coli, ngoba i-Klebsiella, i-Enterobacter, nabanye abavutsheli baba nezindawo ezimnyama phakathi bengacwebezele. Ukuba pinki akusho i-Klebsiella, ngoba abavutsheli abamaphakathi noma abahamba kancane kanye namanye amagciwane abhekwa njengangavutsheli abonakala epinki noma ensomi ngokuphaphathekile. Ukucwebezela akusho ukuthi yi-E. coli ngokuqinisekile, ngoba nabanye abavutsheli abanamandla bangakukhiqiza. Inqubo yokufundisa nemifanekiso yayo yamagciwane akhuliswe exubile kubonisa ngayinye yalezi zindlela zokudukiseka.

Imikhawulo yokuqinisekisa

I-agar ye-EMB ibonisa izici ezibonakalayo, hhayi uhlobo lwegciwane. Amagciwane ahlukene angaba namakoloni abukeka ngokufanayo, futhi igciwane elilodwa lingahluka esithombeni salo esisencwadini yokufunda ngenxa yohlobo lwalo, ubudala, ukuminyana, ingxube, nokufukamela. Yingakho izinqubo zokufundisa nezomtholampilo zithatha ukubukeka kwamakoloni ku-EMB njengokunikeza inkomba yokuqala kuphela.

Inqubo yomsebenzi yomfundi engasekelwa ubufakazi yile: chaza ikoloni elihlukanisiwe (ubukhulu, umbala, indawo ephakathi, ukucwebezela lapho ukukhanya kuvela nge-engeli, izici ezinjengamafinyila), bhala ingxube, isikhathi nezinga lokushisa lokufukamela, kanye nezilawuli; bese udlulisela ikoloni elihlukaniswe kahle kwesinye isiphakeli ukuze uthole ukukhula okuhlanzekile ngaphambi kwanoma yikuphi ukuhlola kokuqinisekisa. Ukuhlola okuvamile okulandelayo kuhlanganisa ukudaya nge-Gram kanye nokusabela kwe-IMViC ukuze kuhlonzwe i-E. coli ecatshangelwayo namagciwane e-coliform, i-TSI noma i-KIA namaqoqo okuhlolwa kwamakhemikhali ezinto eziphilayo aqondene negciwane ngalinye kumagciwane amathumbu, kanye nokuhlolwa kweseroloji, i-MALDI TOF, noma ezinye izindlela zokuhlonza eziqinisekisiwe lapho umsebenzi ukudinga. Ukuze uthole isizinda sendlela i-EMB engena ngayo phakathi kweziphakeli ezikhethayo nezihlukanisayo zamagciwane amathumbu, bheka izingeniso zeziphakeli zokukhulisa amagciwane amathumbu kanye nokuhlola okulandela ukudaya nge-Gram. Mayelana nombuzo ohlobene wokuthi ukudaya islayidi ngokuluhlaza okwesibhakabhaka kungafakazelani futhi kungakwazi ukufakazelani, i-atlasi yokudaya nge-methylene blue nayo igcina okubonwayo nesiphetho kuhlukene ngale ndlela.

Bhala okubonile ngaphambi kwesiphetho. "Amakoloni aluhlaza okwesibhakabhaka ngokumnyama anokucwebezela okuluhlaza okuncike ku-engeli ku-Levine EMB ngemva kwamahora angu-24, okuhambisana nokuvutshelwa kwe-lactose okunamandla" kungasekelwa ubufakazi. "I-E. coli, iqinisekisiwe" kudinga isinyathelo sokuqinisekisa ipuleti lodwa elingakwazi ukusinikeza.