Mega Revision of Microbiology for NEET PG 2023

Introduction

• Focus on high-yield topics in microbiology.
• Emphasis on image-based learning.
• Coverage: Parasitology, Bacteriology, Virology.

Parasitology

Entamoeba histolytica

• Characteristics:
  • Flask-shaped ulcer, commonly seen in the cecum.
  • Anchovy sauce appearance in liver abscess.
• Microscopic Examination:
  • Trophozoites have 1 nucleus; cysts have 4 nuclei.
  • Cartwheel appearance of nucleus in trophozoites.
  • Erythrophagocytosis in trophozoites (ingestion of RBCs).
  • Chromatoid bodies in cysts (composed of ribonucleoprotein).
• Treatment:
  • Metronidazole for 10 days.
  • Paromomycin as a luminal amoebicide.

Balantidium coli

• Characteristics:
  • Largest protozoa; ciliated.
  • Binucleated cysts and trophozoites.
  • Involves large intestine.
• Treatment:
  • Tetracycline or Metronidazole.

Giardia lamblia

• Characteristics:
  • Trophozoites have 2 nuclei; cysts have 4.
  • Falling leaf motility; prominent flagella.
• Treatment:
  • Metronidazole or Tinidazole.

Trichomonas vaginalis

• Characteristics:
  • Causes strawberry cervix; greenish discharge.
  • Only trophozoite form; no cysts.
• Treatment:
  • Metronidazole for sexual partners.

Trypanosoma cruzi

• Characteristics:
  • C-shaped organism; causes Chagas disease.
  • Romana's sign: unilateral eye swelling.
• Treatment:
  • Benznidazole.

Leishmania

• Characteristics:
  • Causes kala-azar; massive splenomegaly.
  • LD bodies in macrophages.
• Treatment:
  • Liposomal amphotericin B.

Bacteriology

Staphylococcus aureus

• Characteristics:
  • Grape-like clusters; golden pigment.
  • Catalase positive; Mannitol salt agar.
  • Yellow color on fermentation.

Streptococcus

• Classification:
  • Alpha, beta, gamma hemolytic.
• Key Organisms:
  • Beta-hemolytic: Streptococcus pyogenes, Streptococcus agalactiae.
• Tests:
  • Lancefield classification, bacitracin test for S. pyogenes.

Mycobacteria

• Characteristics:
  • Granuloma formation; ZN stain for TB.
  • Culture on Lowenstein-Jensen medium.

Viruses

Classification of DNA and RNA viruses

• DNA Viruses:
  • Hepadnaviridae, Herpesviridae, Adenoviridae, Papovaviridae, Parvoviridae.
• RNA Viruses:
  • Picornaviridae, Astroviridae, Caliciviridae, Rotaviridae.

Common Viral Infections

• Cytomegalovirus (CMV):
  • Owl-eye inclusions; causes infections in immunocompromised patients.
• Epstein-Barr Virus (EBV):
  • Infectious mononucleosis; Downy cells.

Conclusion

• Focus on high-yield topics in microbiology is crucial for NEET PG.
• Review images and key characteristics for effective learning.
• Good luck with your studies and preparation.