Medical Microbiology

Some joke time, A Doctor calls the Lab and needs Stat Blood Culture grown in 30  mins.


Boc Micro–>  boc5 microbiologyblood_cult_stat






Table # 1 Gram Positive Catalase (+) Bacteria


From Table #1 I got 3 Questions, those which are in red Squared.

Table # 2 Gram Positive  Catalase (-) Bacteria

Lets Summarise Table #1 and #2
1) Bile Esculin Agar= Group D Strep and Enterococci are positive

2) 6.5% Nacl Broth= Only Enterococci grow, Group D Strep Does not.

3) Optochin Disk = Strep. Pneumoniae is sensitive, Strep Viridian is Resistant.  Remember (oPtochin has  letter P and  pneumonia also starts with P )

4)Bile Solubility: S. pneumonia is Bile soluble.

5) Bacitcin disk sensi= Group A  Strep.

6) SXT =  Both Group A and Group B strep are Resistant.

7)Novobiocin= Staph. Epi is (+) whereas Staph Saphro is (-)

8) PYR + = Group A strep and Enterococci

9) Campt Test= Strep Group B positive.

10) Hippurate Hydrolysis= Greoup B Strep  (+)

Table # 3 Gram (+) Bacillus


Lets Summarize Table # 3

Listeria= Cold Enrichment, Tumbling Motility, Umbrella Growth. Motile at 25 degree Centigrade but not at 37 degre. The only Motile one among Gram pos Bacillus Aerobic Bacteria.

Nocardia= Branched, Partially Acid Fast like Mycobacterium.

B. Anthracis= Spore Forming, Ground Glass Bambmoo shoot like structure, Medussa Head, Causes Anthrax and cutaneous ulcer from handling wool hides in Live Stock.

B Cereus = So this Organism is responsible for Food Poisoning, Toxin Fried Rice.(Just Remember Morning Cereal as food and name of this organism is also Cereus similar name and it causes Food poisoning)

Lactobacillus= Pleomorphic, Flora of Vagina.

Erysipelothrix= H2S+, So causes skin infection in Fisherman or Butchers or rose Growers, In short  it causes Occupational infection.

Corynebacterium= Chinese letter like, Black Colonies on Tindale Agar or Loeffler  Agar Medium. , Confirm by growth in Potassium Tellurite Agar . Highly Toxic Organism. Need to confirm toxicity by ELEK test to check if organism is a producer of toxin, if it  produces then you can report that Species is Toxic.


Table # 4 Gram Negative Enterobactericae


Summary of Table # 4

1) Lactose Ferm= E Coli , Enterobacter,Klebsiella = Mucoid,  Citrobacter= slow Fermenter. 

Klebiseilla has 2 types and can be differentiated on the basis of Indole Test. Kleb Oxytoca is Indole + and Kleb Pneumina is Indole -, How will you remeber which one is Ibdole (+)—-> just remember Oxytoca like oxygen and so indole + 🙂

2) Non Lactose Fermenter= Salmonella, Shigella, Proteus, Morgan and Pseudomonas.
Remember Proteus has 2 types and can be differentiated on the basis of Indole Test
Proteus Vulgaris is Indole + and Port Mirabilis is Indole –
So how do I remember which is positive , just compare Vulgaris with Volcano and its hot and firy and so Indole +
3) TSI reactions = A= Acid means Ferment lactose, sucrose or Glucose
Alkaline =K= No Fermentation.
A on Top means ferment Lactose or Sucrose, A on Bottom means Ferment Glucose. A/A = Ferment through out Slant (Body) and Butt (Bottom)
K/A= means does not ferment Lactose but just Ferment Glucose.
SO look at the Table #4 and see the TSI table.
Colum 1 =A/A = EEKY = first 3—> EEK are Lactose Fermenter and Yersenia just Ferment Sucrose, so the Agar plate with EEK will be pinkish but not with Yersenia bcos its not Lactose Fermenter.
2nd Column = A/A and H2s+ = Citrobacter.
3rd column = K/A= Non Lactose Fermenter , just Glucose Fermenter and does not produce H2S (negative)= SS-PP-M
4th Column= K/A and H2S+= Saci-Pred= Salmonella, Proteus and Mr. Edward 🙂
I just kept Citrobacter so you can remeber that Saci-Pred= H2S+ but Citrobacter had already been placed in column 2 bcos its slow lactose fermenter and have TSI of A/A type.
Column 5= K/K= zero nothing, No fermentation and No H2S=
Pseudomonas. Only Organism which is Oxidase + among this group.

4)Phenyl De Aminase +=PD+=PPM=prot, prov and Morganella.

5)Urease += same like PPM just add K= Klebsiella so= PPM-K = Prot, Prov , Morgan and kleb.
Special case: But  remember  not all of providencia Species  are Urease (+) only and only Providencia Rettgeri  among the Providencia Species is urease (+) and also  Klebseilla is Slow Urease +

6)Citrate += Enter-SePr/K = entero, Serratia, Proteus and Klebsiella.

7)Oxidase + = The ones which end with (-onas)= Pseudomonas and Pleisimonas.

8)H2S+= Saci-PrEd= sexy predator= Sal, Citro, Proteus and Mr. Edwardsiella.

9)Non Motile = The ones ending with (-ella)= Klebsiella and Shigella :)_
Remember how Klebsieilla is pronounced Kleb-siiieeellla takes a long time to read so this organism is very mucoid and cannot move bcos it takes long to read 🙂 

10)Indole += E coli , K Oxytoca (remember as Oxygen), P. Vulgaris (Volcano), Mr. Edward and Mrs Morgan (they both work at my Lab 🙂 ) and finally 2 of which start with P i.e—> Providenscia and Pleisimonas. 🙂

Table # 5 HACEK Group

Table # 6 Haemophilus Gram(-) CoccoBacillus

Summary of Table #6:
These Bacteria will always Grow on Choclate AGar and 10 % Co2 because it supplies both X and V Factors. They do not Grow on Blood Agar because of NADase in the agar ( which inactivates NAD) but will grow on Horse or Rabbit Agar which contains no NADase.
Exception on Growing in Blood Agar can happen only when this bacteria grow around colonies of S Aureus as S. Aureus produces NAD and Hemolyse the Blood cells releasing Hemin as well and this Phenomenon is known as Satellitism.
Both H Influenzae and H. Haemolytics (Not Para’s)  need both X and V Factor
Both Haemolytics (Haemolytics and ParaHaemolytica)= Hemolyse
Both Para (Para Influenz. and Para Haemolytia) need V (NAD) and don’t need (X)
H.Aphrophilus and H Ducreyi = Reactions are exactly opposite For H Aphro= – – – + and H Ducreyi = + – – –

Table # 7  Curved Gram (-) Bacilli AKA Vibrio

Table # 8 Gram (-) Diplococci

Diplococci = Neisseria Species and Moraxella
Neisseria Species Grow on Choclate and selective Media ( MTM, Martin Lewis and NYC)
Neisseria Gonnorhoea Very Resistant ot Penicillin and causes STD
All 3 Neiserria’s Ferment GLucose
Gonnorhea = Only Glucose
Meningitis= starts with M SO ferments Glucose and Maltose
Lactamica = Starts with L and has M in the middle= SO Fermenrs Glucose + Maltose+ Lactose

Table # 9 Gram (+) Anaerobes

Table # 10 Gram (-) Anaerobes

Summary: Fusobacterium = Fus Fus= Brain Abcess, spindle shaped (brain like structure so attack Brain 🙂 )
Last 3 causes Pulmonary Infection and Bacteroides infects below Diaphragm
Brick Red Flouresce = Porphyromas, Prevotella and Veillonella
Indole (+)= Fuso Bacterium and Porphyromas and Both organsims are sensitive to 2 Antibiotics

Table # 11 Zoonotic Diseases Acquired from Animals

Table # 12 Fastidious Gram (-) Rods (Pleomorphic)

Table # 13 Chlamydia and Rickettsiae




Extra Notes: Miscellaneous 

Culture Plate Agar and Their Uses For Memorization ( Very Important)
Culture Plate # 1

Culture Plate # 2


MicroBiology Review in a Nutshell :

Review Page 1:

Review Page 2:

Review Page 3:

Review Page 4:



30 thoughts on “Medical Microbiology

  1. Che

    Thanks for helping us, I’m having a hard time reading your handwritting esp. Table 3 . When you have time can you make it clearer. Also, the picture #1 you added recently in the questions section, is it tear drop cell due to myelofibrosis?

    1. ifzal2013 Post author

      if you just click on the picture once, it zoom a lil bit,.. click
      again and it will look bigger,,,,and the writings you can read easily…
      But don worry I will summarize after each table (on the side of the table)

  2. ifzal2013 Post author

    Yes Tear drop cells mainly in Myelofibrocis, Shistocytesor fragmaented or helmet cells= DIC, Heinz Bodies=Enzyme deficiency G6PD, Burr Cells= Abolioproteinemia,

  3. ifzal2013 Post author

    Nmon. After I finished exam I got fever and also Headache Bcos its been like 6 mos , I did not go to any of my relatives house or any place for fun like movies etc, Just work and ASCP tension.
    Anyways I added the most important Table#4, Make sure when you go to The Exam hall write all mnemonics on right hand corner the board they provide Like Saci-Pred, EEK, Enter_sepr/K etc etc before you start, you might lose 5 mins but its worth it, you are going to answer most of your Micro Questions from this Mnemonics before you forget .
    I wish you good Luck on your Exam.
    I need to watch some movies now…I rented few movies Today 🙂

  4. Nmon

    Really appreciate all your help. I hope I can make it. I will definitely let you know. True, I don’t feel like going out nothing too because of ASCP stress. Same thing I worked and read for ASCP. I will definitely follow your advise. Thanks a lot for helping me and others.

    1. ifzal2013 Post author

      Ok After you r done with 50 Questions, Take a short break for 5-7 mins…drink water, go to restroom relax and go back …in that way if u messed up in the 1st half…u might do better in the 2nd half after break…I did that and I ended 30 mins before too with a Pass 🙂

      1. Clarisse

        Hi Ifzal

        Do we have group mates who recently passed the ascp exam? I’m taking it few weeks from now.. Anybody? Please help.
        Thank you all !!!

  5. Natalie M

    Listeria looks like strep B on blood agar. It is streptex B negative, do gram stain. Short rods- most likely listeria. Raw milk infection

  6. Natalie M

    Aeromonas and plesiomonas are oxidase positive as well. Identifyed in stoolcultures. Also can cause wound infection. ItsBH on blood agar

  7. Natalie M

    E. coli and Salmonella do not appear with flaggells on gram stain. Flagelles are too smsll to be seen under 1000 magnification

  8. Kay

    thanks for all the uploads. may i ask how long is the exam? like how many minutes and how many questions. can you skip the questions and go back later or you cant? did u have enough of time ?

    1. ifzal2013 Post author

      150 minutes i.e. 2 and half hours,
      You cannot move to next Question unless you answer the current one, and you cannot go back to the previous one while you reach Question #100, After answering all the Questions, you can go back and Review, and submit it whenever you feel confident.
      There is also option on top of each question to bookmark or flag, so that if you are not sure of answer you can go back after you answered 100 Q and know which one to focus to correct.

      1. Kay

        thank you so much. I am going to take it soon, maybe this April or May, so Im kindda worried. Thanks for all the tips , you’re awesome!

  9. Che

    Hi, did you encounter identifying biochemical reactions in different tubes and identify what organisms is present? This freaks me out I can’t answer it in the labce micro questions. Malaria smears? Antibody I.d. Panel? Thanks for helping us

    1. ifzal2013 Post author

      All the biochemical reactions for Micro have been explained above….those are most difficult ones.
      Don’t worry about LABCE tooo much, its just to know how much you learnt…you will notice that LabCe repeats same Question 2-3 times in one session, I did not rely on LabCE that much, Go to Strategy Section and read the Techniques.
      Blood Antibody ID panel I only Got 2 ..check Question Section.
      You will hardly get any Malaria smear. Don’t waste too much time on less important things.
      Good Luck 🙂

  10. kakashi

    hi mr. Ifzal….. have u finished taking exam for M(ASCP)? because im planning to take M(ASCP)… I really need an advice and Tips for this exam…Thank you for your notes… This will really help me in my reviews…

  11. Keena

    FOR FAMILY Enterobacteriaceae
    All are GLUCOSE fermenters.
    All reduces Nitrate to nitrite except Pantoea agglomerans
    All are CATALASE POSITIVE except Shigella dysenteriae
    All are MOTILE except Shigella and Klebsiella and at 37degCelcius Yersinia
    All are cytochrome oxidase NEGATIVE

  12. marwa

    First of all thank you for this helpful web and keep it up. I am preparing to take the ASCP in Micro only, and got all the resources you mentioned, i need to know if any one took this categorial exam before to share the experience? Regarding the lab operations and QC questions, from where i can study for this specific part?

  13. marwa

    First of all thank you for this helpful web, keep it up. I am preparing to take the ASCP in Micro. i have all the resources u mentioned in ur web, i need to know if any one took this exam before to share the experience?
    Regarding the part of lab operations and QC what i should know for this categorial exam and what source to study from for this part specifically ?
    Do i expect to see calculation questions in this exam? can u give me examples for these calculations?


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