Prep for USMLEPrep for USMLE
         Forum      |     Resources New Posts   |   Register   |   Login





 identification of bacteria  



Post Reply  
  • 0/5
  • 1
  • 2
  • 3
  • 4
  • 5


Author6 Posts
  #1

hello everyone, i'm mary rose from the philippines. i'm still a student, currently conducting my thesis. And one of my objectives is to identify my isolates up to lowest possible level. I need an expert who could do the confirmation of my identified bacteria. Please, does someone over here can help me..

Anyway, i just did 6 biochemical testing in identifying my isolates, such as the catalase, TSI, SIM, citrate, OF, and urease test and i did the staining techniques.
unfortunately, i only wish to identify those bacteria up to genus level only..

i am hoping someone will have a kind heart in confirming my bacterial identification.. here's my email if anyone would like to communicate with me: maryrosegica@ymail.com

Thanks, everyone! God bless us all.

respectfully yours,
rose




  #2

Um, if you're a student, and doing your thesis, shouldn't you be performing your own analyses?? Just sayin'....


  #3

Hello!
I am looking to identify an unkown bacteria for my class also.... I am just an undergraduate student taking a introduction class to microbiology. I don't know where to begin, but I do know I would like some general direction. Is there some sort of program that I can plug in my results and it can give me a few options?
I found one site, but it didn't seem accurate....
Thank you.


  #4

Make a Gram stain from a fresh plate. Don't use an old plate because it won't give you accurate results (fresh = 18-24 hour old isolate on non-selective medium like TSA or TSA with 5% sheep blood).

If it is gram negative, do an oxidase. If oxidase negative, chances are it is a member of the Enterobacteriaceae, but not always. Perform ImVic testing with whatever media you have available on a subculture made from subbing only one colony. If you receive your unknown on a slant you will have to sub it to some media. Streak well for isolation. ImVic is Indole/motility/VP, citrate I think. Indole must be performed from a blood plate or medium that will give you accurate results with indole reagent (SIM is one).

Based on results of your biochemical tests, you should be able to narrow down what you have. Subculturing to either MacConkey or EMB agar will give you the lactose reaction, which is very important.

If it's a gram positive cocci, is it in clumps or chains? Sometimes it's hard to tell on a smear. You must perform catalase testing. Catalase positive organisms give LOTS of bubbles with 3% H2O2. Catalase negative organisms either give no reaction at all (ideal) or a couple of weak bubbles if you take the organism from a blood agar plate. Blood agar can sometimes give you misleading catalase reactions so be careful.

Once you have your basic microscopic morphology on a PURE CULTURE down, the lab you're working with should have some basic identification media available to help solve your unknowns.

Basic micro texts like Bergey's manual give reactions to basic organisms. I would think this would be a reference book available to you in your class. www.amazon.com/Bergeys-Manu...UTF8&qid=1337226621&sr=1-1

Good luck.


  #5

I learned the analysis of unknown bacteria as an intern in a lab. That's the best way - not at uni but in a specific professional field.


  #6

Yes, I think it's much better to learn in that fashion. Memorizing lists of Oxidase positive, catalase positive, indole positive organisms is not the way to do it if microbiology is going to make any sense at all. However, I suppose if you're just memorizing for a test and going to forget about it the minute you walk out of the room...confused





Bookmark and Share





Login or Register to post messages








show Similar forum topics

Identification of slides
Problem with identification
Identification form
show Related resources









Advertise | Support | Privacy | TOS | Premium | Contact