Who else is taking/has taken Microbiology?? - page 5

Hi all! Anyone out there taking Micro this quarter?? I am and so far its pretty hard! Thought we could start a thread about our micro experiences...I had my first test today and it was soo hard... Read More

  1. by   LeiaT
    Okay, here goes, you ready??! hahaha...


    Media: the reason that media changes (differential media) is to differentiate between different organisms (for instance, Mannitol Salt Agar is differential for S. aureus. Only S. aureus can metabolize d-Mannitol, an ingredient in the agar, and it changes to the color gold).

    selective media: a medium that allows growth of some species and suppressed growth of other species by adding certain ingredients to the medium.

    differential media: if an indicator is incorporated into a medium at one color and the growth from the desired species changes the pH around the developing colonies, a different color will appear.


    what makes MAC and MSA selective and diff
    MacConkey Agar--selective: Bile Salts, differential: Lactose
    Mannitol Salt Agar--selective: Sodium Chloride, differential: d-Mannitol

    what mmakes BAP differential--Blood Agar Plate? I'm not sure, I know it's used for Beta/Alpha/Gamma hemolysis.


    why does the agar turn purple/yellow/brown
    don't understand your question

    organisms grown on each medium
    here are some selective and/or differential agar and what they grow:
    MANNITOL SALT AGAR--selective because only Staphylococcus grow, differential because of d-Mannitol (S. aureus metabolizes it)
    SIMMONS CITRATE AGAR--only differential. only organisms that can break down sodium citrate turn the agar blue, because of the pH indicator Brom Thymol Blue
    MACCONKEY AGAR--selective because it only grows Gram - rods. Neutral Red and Crystal Violet make it differential (for what, I forgot, sorry)
    E.M.B AGAR--Selective for Gram - rods. Differential for E. coli, which turn metallic green.

    enriched media--has elaborate or highly specific nutrients

    fastidious--

    why use "lactose" as an indicator--unsure of what questions means...i know to make it differential..but is that what you mean?

    how organisms affect the agar, staph, strep, gnb--which agar?

    Hemolysis-alpha/beta/gamma
    alpha--partial hemolysis--greenish color
    beta--complete hemolysis of RBCs on plate--red--agar becomes transparent
    gamma--no effect

    gram stain steps/colors:
    1. Crystal violet (primary stain)--Stains all
    2. Gram's iodine (mordant)--fixes stain on cells
    3. alcohol-acetone solution (decolorizer)--decolorizes G-neg.
    4. Safranin (counterstain)--stains G-neg cells.


    Hope this helps, let me know if I forgot anything or you need more help or if something's not clear.
  2. by   SCmomof3
    Wow - very informative post. Thanks for taking the time to do that.

    We had our third class/lab tonight. We had to look at various bacteria under the oil immersion scope and identify them. Those suckers are hard to see!! I am so blind - I'm going to be in trouble. I think part of the problem was poorly stained slides though. Some slides were much better than others, and thus, easier to identify.
  3. by   truern
    Don't make the mistake I did in Micro....I had just got new MONOVISION contact lens and couldn't see a thing in the microscope :chuckle

    To make matters worse, I could have just taken out the one for far vision, but I can only squint with one eye. Wanna guess which eye had the near vision contact?!?
  4. by   tanaynicole
    I'm taking my Micro final next week ( the 23rd). I wish had found this site earlier, I would have been great to have someone else to complain to than my boyfriend. My instructor is great and I really love the class...but the test were murder!! 6 questions, all 15+ points all essay and my instructor is one that wants real detail, Pictues discription the whole works!! All I can can say is thank GOD for lab or else I don't think I would be passing the class.

    Good luck to all taking finals this week!!
  5. by   GrnHonu99
    Quote from LeiaT
    Okay, here goes, you ready??! hahaha...


    Media: the reason that media changes (differential media) is to differentiate between different organisms (for instance, Mannitol Salt Agar is differential for S. aureus. Only S. aureus can metabolize d-Mannitol, an ingredient in the agar, and it changes to the color gold).

    selective media: a medium that allows growth of some species and suppressed growth of other species by adding certain ingredients to the medium.

    differential media: if an indicator is incorporated into a medium at one color and the growth from the desired species changes the pH around the developing colonies, a different color will appear.


    what makes MAC and MSA selective and diff
    MacConkey Agar--selective: Bile Salts, differential: Lactose
    Mannitol Salt Agar--selective: Sodium Chloride, differential: d-Mannitol

    what mmakes BAP differential--Blood Agar Plate? I'm not sure, I know it's used for Beta/Alpha/Gamma hemolysis.


    why does the agar turn purple/yellow/brown
    don't understand your question

    organisms grown on each medium
    here are some selective and/or differential agar and what they grow:
    MANNITOL SALT AGAR--selective because only Staphylococcus grow, differential because of d-Mannitol (S. aureus metabolizes it)
    SIMMONS CITRATE AGAR--only differential. only organisms that can break down sodium citrate turn the agar blue, because of the pH indicator Brom Thymol Blue
    MACCONKEY AGAR--selective because it only grows Gram - rods. Neutral Red and Crystal Violet make it differential (for what, I forgot, sorry)
    E.M.B AGAR--Selective for Gram - rods. Differential for E. coli, which turn metallic green.

    enriched media--has elaborate or highly specific nutrients

    fastidious--

    why use "lactose" as an indicator--unsure of what questions means...i know to make it differential..but is that what you mean?

    how organisms affect the agar, staph, strep, gnb--which agar?

    Hemolysis-alpha/beta/gamma
    alpha--partial hemolysis--greenish color
    beta--complete hemolysis of RBCs on plate--red--agar becomes transparent
    gamma--no effect

    gram stain steps/colors:
    1. Crystal violet (primary stain)--Stains all
    2. Gram's iodine (mordant)--fixes stain on cells
    3. alcohol-acetone solution (decolorizer)--decolorizes G-neg.
    4. Safranin (counterstain)--stains G-neg cells.


    Hope this helps, let me know if I forgot anything or you need more help or if something's not clear.

    OMG you SAVED my life!!!!!!!! I had to resched. my test bc I just couldnt take it yesterday....im pulling 10-12 hr school days and try to study but with such a heavy course load its hard to come home and put in 3-5 more hours of studying every night..so THANKS SOOO MUCH!!! when I get an A on the test i'm going to dedicate it to you lol!!!
  6. by   LeiaT
    You're welcome...sounds like you have your hands full. I hope you get an A, too. Is this for your lab test or lecture test?
  7. by   kdredman
    [font=Comic Sans MS]Hi!! I'm taking Micro, second part of summer. Thanks for the updates....I will keep reading. If anyone out there replied to any of kdredman will you please send me your replies again. I really value what you have to say. Thanks. Good Luck in micro.
    Quote from galaxy781
    Hi all!

    Anyone out there taking Micro this quarter?? I am and so far its pretty hard! Thought we could start a thread about our micro experiences...I had my first test today and it was soo hard over 80 questions.....ugh...we had to grow some smelly bacteria this week too....My instructor is not very good at lecturing and forgets to actually lecture then she just expects you to know it....how am i supposed to know what hemolysis is if you dont tell me! ANyway, here is a good link for micro...it has some awesome quizzes and online notecards...www.mhhe.com/talaro5

    We can make this thread for anything to do with Micro! Where is everyone from and where are you taking micro and for what program??
    Last edit by kdredman on May 20, '05 : Reason: spelling
  8. by   GrnHonu99
    Quote from LeiaT
    You're welcome...sounds like you have your hands full. I hope you get an A, too. Is this for your lab test or lecture test?

    Thanks! well i just got back from my test and i think i aced it we have lab and lecture but we dont have a seperate lab grade. The test I took today was over specific things that we have learned in lab....we had our 2nd test last week over the regualr course specific things.....

    I am thinking about posting some review sheets with answers on my website and maybe some power point slides, would this benefit anyone? If anyone would like to see some of them let me know and i'll let you know when they are up. I am trying to keep a website or blog all about my nursing school exp. with all my academic classes and whatnot...kinda like an online filing cabinet...lol....im going to try and post some AP stuff too along with Patho and Pharm as soon as I get a chance!!!

    thanks again for the help!
  9. by   GrnHonu99
    Quote from Seren21
    Micro was the first class I took when I decided to try for a BSN degree - seems like a bizillion years ago - in '01. Boy was I in for a shock. Up until that point I had been taking semi-easy general ed classes. Micro was not easy - I made a 60 something on the first test (and I'm usually an A student). After that it was memorize, memorize, memorize. And for labs we not only had to grow stuff that stank, we had timed tests, like find the bacterium with a microscope in 30 seconds and pour auger into plates (-10 pts for every drop you spill). It seemed like torture at the time, but it helped me prepare for checkoffs in nursing school, and for that I'm thankful.
    So hang in there and study hard, because you'll need the skills you're learning now for nursing school.

    Seren
    LMAO...the bacteria is SOOOO smelly! thats so funny that they made you pour the agar...lol talk about cheap labor! hope you had steady hands too!
  10. by   LeiaT
    Quote from ELKMNin06
    LMAO...the bacteria is SOOOO smelly! thats so funny that they made you pour the agar...lol talk about cheap labor! hope you had steady hands too!
    Ever smell Proteus??? UGGGGHHHHHHHH!!! Shew.
  11. by   GrnHonu99
    Quote from LeiaT
    Ever smell Proteus??? UGGGGHHHHHHHH!!! Shew.

    dont think so but im sure ill have the pleasure soon!!! lol... i have such a sensitive sense of smell so I can smell them through the agar plates...sometimes when i have to describe them i have to look kinda close and since there is always condensation on the lid i have to take it off and stick it right in my face..ugh....lol
  12. by   nurse2be2007
    I took Microbiology last semester and managed to pull off an A in the class but it wasnt easy. Not because the class was hard but because the professor sucked so bad. It is so true that a good professor makes all the difference. I really dont feel like I learned anything in that class, in fact, we missed out on 6 labs because the lab tech was out sick and the professor wouldnt set up the lab for us. So over all we missed out on a lot of important information. If I have any extra time I may pay to audit micro with a different teacher so I can really experience what this class is suppose to be about. You dont even want to know about our unknown bacteria final LMAO what a joke!
  13. by   LeiaT
    Quote from ELKMNin06
    dont think so but im sure ill have the pleasure soon!!! lol... i have such a sensitive sense of smell so I can smell them through the agar plates...sometimes when i have to describe them i have to look kinda close and since there is always condensation on the lid i have to take it off and stick it right in my face..ugh....lol
    Believe me, if someone swabs something and Proteus shows up, it will smell up the lab room as soon as the incubator is opened!!! Nasty!

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