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what bacteria?


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#1 elzattara

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Posted 17 October 2009 - 01:13 AM

Hello,

I've done some tests on a certain bacteria and i'm getting thse results.
-on VRBG plate : just some red/pink colonies

-Tergitol 7-agar : alot red/brown colonies=> could be salmonella, shigella, proteus of pseudomonas

-on the EMA i don't have growth => no E.coli
-BLO 2%: no gas

-op het CLED medium i have white colonies : lactose -

-ureum -

-citraat -

-KIA : - + + -

-TSI : After 1,5 day in the incubator the tongue was reasonable red and the blunt was yellow. Then i put the TSI on my rack and the other day the tongue was almost totally yellow. Not much later is was completely yellow. So I doubt if it's + + + - or "- + + -" sucrose + or -?

-lysinedecarboxylase +

- lysinedeamine -

-indool -

-mobiliteit -

-ornithinedecarboxylase -

-H2S -

I just have some pages of the bergey's manual for me and I think it could be Klebsiella ozaenae or Salmonella gallinarum. Also Hanfia alvei seems to be a good match. Do you think this is correct or you think it's another bacteria?

grtz

Edited by elzattara, 17 October 2009 - 02:38 AM.


#2 GeorgeWolff

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Posted 17 October 2009 - 10:55 AM

Sorry elzattara - either you haven't paid attention in class or you have a very poor instuctor. One doesn't attempt ID without some key - some program for application of data. You have here a bunch of overlapping and somewhat inconsistent results absent some of pivotal initial tests that any ID should include.

An instructor worth a damn provides a context to ID's - clinical, environmental, industrial, etc. - just as one encounters isolates in real life.
First, perform a Gram stain and run catalase and oxidase.
Assuming it's Gram neg, cat + and ox - many of the media chosen are pretty useless. The next test objective should be to determine if it ferments glucose and lactose. VRGB and Tergitol ("brown" is not a typical result) are pretty uselss if you're running TSI / KIA (why run both?). What are "EMA" and "BLO"? Colony pigmentation on CLED is not signficant- it's the medium color that's indicative and this too is not so useful here.

So it looks like a nonmotile non-coliform enteric; that's citrate, indole, H2S (Tergitol aside), lysine daminase and ornithine decarb neg; and lysine decarboxylase pos. If I understand your notation - it produced no gas in KIA and TSI.

ozaenae is a subspecies of Klebsiella pneumoniae and should be citrate pos (use Christensen' - Simmon's may not be useful here).
Hafnia fits but for motility (check again after room temp inciubation and look at it under the scope)
gallinarum fits but for LDC neg and prob not likely.

#3 elzattara

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Posted 17 October 2009 - 02:36 PM

Sorry elzattara - either you haven't paid attention in class or you have a very poor instuctor. One doesn't attempt ID without some key - some program for application of data. You have here a bunch of overlapping and somewhat inconsistent results absent some of pivotal initial tests that any ID should include.

An instructor worth a damn provides a context to ID's - clinical, environmental, industrial, etc. - just as one encounters isolates in real life.
First, perform a Gram stain and run catalase and oxidase.
Assuming it's Gram neg, cat + and ox - many of the media chosen are pretty useless. The next test objective should be to determine if it ferments glucose and lactose. VRGB and Tergitol ("brown" is not a typical result) are pretty uselss if you're running TSI / KIA (why run both?). What are "EMA" and "BLO"? Colony pigmentation on CLED is not signficant- it's the medium color that's indicative and this too is not so useful here.

So it looks like a nonmotile non-coliform enteric; that's citrate, indole, H2S (Tergitol aside), lysine daminase and ornithine decarb neg; and lysine decarboxylase pos. If I understand your notation - it produced no gas in KIA and TSI.

ozaenae is a subspecies of Klebsiella pneumoniae and should be citrate pos (use Christensen' - Simmon's may not be useful here).
Hafnia fits but for motility (check again after room temp inciubation and look at it under the scope)
gallinarum fits but for LDC neg and prob not likely.


The only certain thing is that it's an Enterobacteriaceae. I had gas production in KIA and TSI. the only thing i doubt about is if it's sucrose + or -. KIA and TSI also showed it was HS2 neg.
EMA = easine methyleenbleu agar for E.coli. But I don't have an E.coli. BLO = Briljantgreen lactose => nog gas. The incubation was at 37 degrees so normally K. ozazenae should be motility -. :(

Edited by elzattara, 17 October 2009 - 10:59 PM.


#4 elzattara

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Posted 18 October 2009 - 02:10 AM

I searched a bit more and what do you think about Shigella "flexneri?" ?

#5 elzattara

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Posted 18 October 2009 - 07:56 AM

the BLO 2% is normally for coliforms if you have gas. Since I have no gas it shouldn't be Hafnia and Klebsiella. What do you think about Shigella? Only the lysinedecarboxylase test looks wrong.

#6 GeorgeWolff

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Posted 21 October 2009 - 01:54 PM

I'd not be so confident you have an enteric. No growth on Eosin methylene blue agar is inconsistent with that group.

Do a Gram stain, catalse and oxidase.




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