1. Anatomy
    2. 1. General anatomy
    2. General histology
    3. General embryology
  2. Physiology
    3. 4. Functional Organization and Internal Environment
    5. Cell Membrane and Communication
    6. Bioelectricity
    7. Ageing and Yoga
    8. Blood
  3. Pharmacology
    4. 9. General Pharmacology
    10. Antibacterial agents
    11. Antifungal agents
    12. Antiviral agent
    13. Antimalarial, anti-kalazar and antifilarial drugs
    14. Anticancer drugs
  4. Pathology
    5. 15. Cellular Adaptation, Injury, and Death
    16. Inflammation and Repair
    17. Hemodynamic Disorders, Thromboembolic Disease, and Shock
    18. Neoplasia
    19. Diseases of the Immune System
  5. Microbiology
    6. 20. General microbiology
    21. Immunology
  6. Biochemistry
    7. 22. Introduction to biochemistry
    23. Metabolism
    24. Vitamins
    25. Nucleic acids DNA and RNA
Microbiology
20. General microbiology
CONTRIBUTION OF MICROBIOLOGY TO MEDICAL SCIENCE

1.

Write on Robert Koch's contributions in medical microbiology.

[2053]

➤

2.

Write short notes on: Koch's postulates

(2.5)

[2078]

➤

MICROBIAL FLORA INDIGENOUS MICROBIOTA

1.

Describe the beneficial and harmful roles of Normal flora.

(5)

[2071, 2070]

➤

TRANSMISSION OF MICROORGANISMS
STERILIZATION, DISINFECTION AND DECONTAMINATION

1.

How do you sterilize:
  1. Apron
  2. Operation theater
  3. Surgical scalpel
  4. Nutrient broth
  5. Plastic syringe

[2067]

➤

2.

Define sterilization and disinfection. Describe the methods of sterilization.

[2069]

➤

3.

Define sterilization. Describe the principle of autoclave.

(1+4=5)

[2072]

➤

4.

List different methods of sterilization. Briefly describe hot air oven.

(3+3=6)

[2074]

➤

5.

Define sterilization. Describe the principle of Autoclave.

(2+3=5)

[2078]

➤

BACTERIOLOGY

1.

Write the morphological classification of bacteria.

[2068]

➤

2.

Write the principle of Gram's stain. Give any two examples of Gram positive and Gram negative bacteria.

[2068]

➤

3.

Sketch a diagram of bacterial cell and label it properly.

[2066]

➤

4.

Describe how bacteria differ from viruses.

[2058]

➤

5.

Define toxin, exotoxin, endotoxin and enterotoxins.

[2053]

➤

6.

Write short note on AFB stain.

[2056]

➤

7.

Describe the difference between endotoxin and exotoxin.

[2069]

➤

8.

Write down the basic composition of culture media. List any 3 culture media which are used in routine bacteriology.

[2069]

➤

9.

Write short notes on: Gram stain

[2074]

➤

Property
Gram staining
Acid fast staining
Primary stain
Violet/ Blue color (Crystal violet)
Pink/ Red color (Carbon fuchsin)
Mordant
Iodine
Simple heat
Decolorizer
Alcohol or Acetone
20% \(H_2SO_4\)
Secondary stain
Pink/ Red color (Carbol fuchsin)
Blue/ Violet color (Methylene blue)
▢ Gram stain:
❖ Theories:
◉ 1. Protoplasmic pH theory:
◈ Principle: Basic dyes have greater affinity for acidic components.
◈ Explanation: Gram-positive bacteria have lower (more acidic) protoplasmic pH, allowing stronger dye binding and resistance to decolorization.
◉ 2. Cell wall permeability theory:
◈ Principle: Differences in cell wall permeability affect dye retention.
◈ Explanation: Gram-negative bacteria have more permeable cell walls, allowing crystal violet to wash out easily during decolorization.
◉ 3. Magnesium ribonucleate theory:
◈ Principle: Complex of magnesium ribonucleate with basic dye stabilizes dye retention.
◈ Explanation: Gram-positive bacteria retain the dye due to presence of magnesium ribonucleate in cytoplasm.
◉ 4. Role of Iodine:
◈ Principle: Iodine acts as a mordant.
◈ Explanation: Forms a dye-iodine complex and increases acidity of protoplasm, enhancing dye retention in Gram-positive bacteria.
▢ Acid fast structures:
❖ Bacteria:
  1. Legionella
  2. Mycobacterium
    1. Mycobacterium tuberculosis
    2. Mycobacterium leprae
  3. Nocardia
  4. Smegma bacilli
❖ Parasites:
  1. Cryptosporidium
  2. Cyclospora
  3. Cystoisospora
❖ Bacterial spore:
❖ Spermatic head:
▢ Albert stain:
❖ Stains used:
  1. Malachite green
  2. Toluidine blue
  3. Iodine
❖ +ve Bacteria (@MSC GArden):
  1. Mycobacterium
  2. Spirillum volutans
  3. Corynebacterium diphtheriae
  4. Gardenella vaginalis
  5. Agrobacterium tumefaciens
❖ Granules name:
  1. Volutin granules → Discovered in Spirillum volutin bacteria
  2. Babes Ernst granules → Discovered by Babes Ernst
  3. Polar bodies → Due to presence at the poles
  4. Metachromatic granules → Due to blue in color
❖ Metachromatic granules stained with (@PLAN):
  1. Ponder's stain
  2. Loeffler's methylene blue
  3. Albert's stain
  4. Neisser's stain
▢ Bipolar staining/ Safety pin appearance:
Stains are stained at poles or ends.
❖ Examples:
    Can produce very high yield stain
  1. Campylobacter granulomatis
  2. Pseudomonas mallei/ Psedomallai
  3. Vibrio parahemolyticus
  4. Hemophilus ducreyi
  5. Yersinia pestis
▢ Aerobic and Anaerobic bacteria:
❖ Obligate anaerobe:
  1. Clostridia
  2. Bacteroides
  3. Actinomyces
▢ Spore forming bacteria:
❖ Spore forming bacteria @BSC Chemistry:
  1. Bacilli antracis and subtilis
  2. Sporosarina
  3. Clostridia
  4. Coxiella brnetti
▢ Capsulation:
❖ Capsulated:
  1. Streptococcus pyogenes
  2. Streptococcus pneumoniae
  3. Neisseria meningitidis
  4. Bacillus anthracis
  5. Clostridium perfringes and butyricum
  6. Klebsiella pneumoniae
  7. Pseudomonas aeruginous
  8. Hemophilus influenzae
  9. Bacteriodes fragilis
  10. Vibrio parahemolyticus
  11. Yersinia
▢ Motility:
❖ Motile bacteria:
◉ Peritrichous flagella (@Cute Baby SLEePing):
  1. Bacillus except B. antracis
  2. Clostridia all except C. perfringes and C. tetani
  3. Salmonella except S. gallenarum-pullorum
  4. E. coli
  5. Proteus
  6. Listeria monocytogen
◉ Polar flagella (@Very Protective Solution HCL):
  1. Vibrio
  2. Spirochete
  3. Pseudomonas
  4. Helicobacter pylori
  5. Campylobacter
  6. Legionella
Types of Motility
Bacteria
Tumbling motility
Listeria
Gliding motility
Mycoplasma
Stately motility
Clostridium
Darting motility
  1. Vibrio cholerae
  2. Campylobacter
Swarming on agar plate
  1. Proteus
  2. Clostridium tetani
Corkscrew, lashing, flexion extension motility
Spirochete
Property
Exotoxins
Endotoxins
Composition
Proteins
Lipoprotein-lipopolysaccharide (LPS) complexes
Effect of Heat
Heat labile (destroyed by heat), except *C. botulinum* toxin (heat stable)
Heat stable
Secreted by
Secreted by living bacterial cells
Not secreted; part of outer membrane of Gram-negative bacteria
Antigenicity
Strong
Weak
Produced by
Primarily Gram-positive bacteria (some Gram-negative too)
Only Gram-negative bacteria
Toxicity
Highly toxic; fatal in microgram amounts
Moderately toxic; toxic in 0.1–0.2 mg amounts
Filtrability
Filtrable
Not easily filtrable
Convertibility to Toxoid
Yes – can be converted to toxoid for vaccines
No – cannot be converted to toxoid
▢ Culture media:
❖ Types of Culture media:
◉ Based on Consistency:
◈ Liquid:
◈ Semisolid:
◈ Solid:
◉ Based on Method of growth detection:
◈ Conventional culture media:
■ Simple/ Basal media:
● Constituents:
  1. Water
  2. Electrolyte
  3. Peptone
  4. Meat extract
  5. Agar
    1. Composition → 2%
    2. Used only for solidifying and not for nutrient purpose.
● Peptone water:
● Nutrient broth:
● Nutrient agar:
● Semisolid medium:
■ Enriched media:
● Constituents:
    It contains either one of them.
  1. Blood
  2. Serum
  3. Egg
● Uses: Used to grow fastidious organism. (Bacteria requiring specific nutrients)
● Blood agar:
⟣ Example:
⟣ Uses:
  1. To study hemolytic property of the bacteria.
    2. ⬦ β-hemolysis (Complete hemolysis):
    ⬦ α-hemolysis (Incomplete hemolysis):
    ⬦ γ-hemolysis (No hemolysis):
● Chocolate agar:
⟣ Example:
  1. Neisseria
  2. Haemophilus
● Leoffler's serum slope:
⟣ Example: Corynebacterium diphtheriae
● Blood culture media:
⟣ Example:
Note
Enrichment and Selective media allow specific organism to grow.
■ Enrichment broth:
  1. They are liquid media.
● Tetrathionate broth:
  • •
    Used for isolation of Salmonella Typhi
● Selenite F broth:
  • •
    Used for isolation of Shigella
● Gram-negative broth:
  • •
    Used for isolation of Shigella
● Alkaline peptone water (APW):
  • •
    Used for isolation of Vibrio cholerae
■ Selective media:
  1. They are solid media.
● Lowenstein-Jensen(LJ) medium:
  • •
    Used for isolation of Mycobacterium tuberculosis
● Thiosulphate citrate bile salt sucrose (TCBS) agar:
  • •
    Used for isolation of Vibrio
● DCA (Deoxycholate citrate agar) and XLD (Xylose lysine deoxycholate) agar:
  • •
    Used for isolation of Salmonella and Shigella
● Potassium tellurite agar (PTA):
  • •
    Used for isolation of Corynebacterium diphtheriae
● Tindale tellurite agar:
  • •
    Used for isolation of Corynebacterium diphtheriae
■ Differential media:
They differentiate two groups of bacteria by using an indicator, which changes the color of the colonies of a only particular group of bacteria.
● MacConkey agar:
● CLED agar (Cysteine lactose electrolyte-deficient agar):
■ Transport media:
● Neisseria:
  1. Amies medium
  2. Stuart's medium
● Vibrio cholerae:
  1. VR (Venkatraman-Ramakrishnan) medium
  2. Autoclaved sea water
  3. Cary Blair medium
● Salmonella, Shigella:
  1. Buffered glycerol saline
  2. Cary Blair medium
■ Anaerobic media:
● Robertson's cooked meat (RCM) broth:
● Others anaerobic media:
  1. Thioglycollate broth
  2. Anaerobic blood agar
  3. BHIS agar (Brain-heart infusion agar) with supplements (vitamin K and hemin)
  4. Neomycin blood agar
  5. Egg yolk agar
  6. Phenyl ethyl agar
  7. Bacteroides bile esculin agar (BBE agar)
◈ Automated culture media:
■ BacT/ ALERT 3D:
■ BacT/ ALERT VIRTUO:
■ BACTEC (BD Diagnostics):
ANAEROBIOSIS

1.

Write short notes on: Anaerobiasis

[2074]

➤

▢ Definition: Anaerobiasis is the creation of oxygen-free conditions necessary for the growth of obligate anaerobes.
▢ Methods of Producing Anaerobic Conditions:
❖ 1. By displacement of oxygen:
◉ Vacuum cultivation: Air is evacuated from the container to remove oxygen.
◉ Displacement by inert gases: Oxygen is displaced by flushing sealed jars with inert gases like hydrogen or nitrogen. Inoculated meat is often used as substrate.
❖ 2. Absorption of oxygen by chemicals:
◉ Pyrogallic acid: Absorbs oxygen when combined with alkali (e.g., NaOH).
◉ Chromium and sulfuric acid mixture: Strongly absorbs oxygen from the environment.
◉ GasPak method: Hydrogen reacts with oxygen in presence of palladium catalyst to form water, removing O₂ from the chamber.
❖ 3. By displacement and combustion of oxygen:
◉ McIntosh and Filde's anaerobic jar:
◈ Principle: Hydrogen gas is introduced and combines with oxygen in presence of palladium or platinum catalyst to form water.
◈ Catalyst: Spongy palladium or platinum.
◈ Indicator: Reduced methylene blue – blue in presence of O₂, colorless in anaerobiasis.
❖ 4. Biological method:
◉ Principle: Uses oxygen-consuming aerobic organisms to create an anaerobic environment for obligate anaerobes.
◉ Example: One plate inoculated with *Pseudomonas aeruginosa* or *Serratia marcescens* (aerobes), placed inverted over a plate with anaerobic specimen and sealed around the rim.
❖ 5. Incorporation of reducing agents in media:
◉ Thioglycollate broth: Contains sodium thioglycollate to reduce dissolved oxygen; supports growth of anaerobes.
◉ Robertson's cooked meat medium: Contains reducing substances (e.g., meat particles) and nutrients for anaerobes; used for enrichment culture.
VIROLOGY

1.

List the general properties of viruses.

[2069]

➤

2.

List the important oncogenic viruses.

[2060]

➤

3.

Write about the general properties of viruses. List viruses causing encephalitis.

(3+2=5)

[2074]

➤

▢ General properties of viruses:
  1. Obligate intracellular parasites – require host machinery for replication.
  2. Contain only one type of nucleic acid – either DNA or RNA, not both.
  3. Lack cellular organelles – no ribosomes, mitochondria, etc.
  4. Do not divide by binary fission – replicate by assembly of components.
  5. Size ranges from 20 to 300 nm – filterable agents.
  6. Have a protein coat (capsid), and some have an outer lipid envelope.
  7. Infect all life forms – animals, plants, bacteria (bacteriophages).
▢ Important oncogenic viruses:
  1. Human papillomavirus (HPV) – cervical cancer.
  2. Hepatitis B virus (HBV) – hepatocellular carcinoma.
  3. Hepatitis C virus (HCV) – hepatocellular carcinoma.
  4. Epstein-Barr virus (EBV) – Burkitt lymphoma, nasopharyngeal carcinoma.
  5. Human herpesvirus 8 (HHV-8) – Kaposi sarcoma.
  6. Human T-cell lymphotropic virus type 1 (HTLV-1) – adult T-cell leukemia/lymphoma.
▢ Viruses causing encephalitis:
  1. Herpes simplex virus (HSV)
  2. Japanese encephalitis virus (JEV)
  3. Rabies virus
  4. Enteroviruses (e.g., Coxsackie, Echovirus)
  5. West Nile virus
PARASITOLOGY
MYCOLOGY
INFECTION
ANTIMICROBIAL AGENTS
LABORATORY DIAGNOSIS OF
INFECTIOUS WASTE MANAGEMENT
MICROBIAL GENETICS