General Bacteriology

• Matching Rickettsial and Anaplasmataceae Organisms with Clinical Diseases:
• Anaplasma phagocytophilum $\longrightarrow$ (III) Tick-borne fever in ruminants / Granulocytic anaplasmosis: Infects neutrophils of sheep, cattle, and horses, transmitted by Ixodes ticks.
• Anaplasma platys $\longrightarrow$ (I) Canine cyclic thrombocytopenia: Infects blood platelets (thrombocytes) in dogs, leading to cyclic drops in platelet counts.
• Ehrlichia canis $\longrightarrow$ (IV) Canine monocytic ehrlichiosis: Infects circulating monocytes and macrophages in dogs, transmitted by the brown dog tick (Rhipicephalus sanguineus).
• Ehrlichia ewingii $\longrightarrow$ (II) Canine granulocytic ehrlichiosis: Infects granulocytes (neutrophils) in dogs, transmitted by Amblyomma americanum.
• Conclusion: (A) - (III), (B) - (I), (C) - (IV), (D) - (II) (Option 1).

Correct option: (1) (A) - (ill), (B) - (1), (C) - (IV), (B) - (I)

• Pathophysiology of Anthrax Toxins (Bacillus anthracis):
• Enzymatic Identity: Anthrax Edema Toxin is composed of Protective Antigen (PA) and Edema Factor (EF). EF is an intrinsic, calcium/calmodulin-dependent adenylate cyclase that dramatically elevates intracellular cAMP ($\gt 1,000$-fold), inducing massive tissue edema. Lethal Factor (LF), by contrast, is the zinc-dependent metalloprotease that cleaves MAP kinase kinases (MAPKKs) [Statement A is FALSE].
• Impairment of Phagocytosis: Markedly elevated cAMP levels disrupt cellular actin cytoskeletal dynamics, preventing macrophages and dendritic cells from phagocytosing and internalizing bacteria [Statement B is TRUE].
• Lymphocyte Depletion: EF suppresses T-cell and B-cell receptor-mediated activation and induces apoptosis, decreasing circulating lymphocyte numbers [Statement C is TRUE].
• Neutrophil Deactivation: Strongly impairs the generation of reactive oxygen species (oxidative burst) and migratory chemotaxis in neutrophils [Statement D is TRUE].

Correct option: (4) (B), (C) and (D) only.

• Bacteriological Hallmarks of Clostridium perfringens:
• Motility: C. perfringens is famously non-motile (lacks peritrichous flagella), unlike most other pathogenic clostridia (e.g., C. tetani, C. septicum, C. chauvoei) [Statement A is FALSE].
• Stormy Clot Reaction: In litmus milk, rapid fermentation of lactose with massive acid production coagulates casein into an acid curd, while vigorous gas generation ($\text{CO}_2$ and $\text{H}_2$) violently tears and fractures the clot ('stormy fermentation') [Statement B is TRUE].
• Sugar Fermentation: Ferments glucose, lactose, sucrose, and maltose with acid and gas [Statement C is TRUE].
• Capsulation: Forms a distinct polysaccharide capsule in vivo in infected animal tissues and wound exudates [Statement D is TRUE].

Correct option: (4) (B), (C) and (D) only.