• Campylobacter jejuni and Guillain-Barré Syndrome (GBS):
• Pathogen Characteristics:
• Campylobacter jejuni is a microaerophilic, curved Gram-negative motile bacterium shed by dairy cattle and transmitted via consumption of raw, unpasteurized milk.
• Pathogenesis of GBS:
• It is the leading antecedent trigger of Guillain-Barré Syndrome (GBS), an acute autoimmune polyneuropathy characterized by ascending motor paralysis.
• Arises from molecular mimicry: Antibodies directed against the core lipooligosaccharide (LOS) of C. jejuni cross-react with human peripheral nerve gangliosides (GM1, GD1a), causing autoimmune demyelination.
• Conclusion: Campylobacter jejuni (Option 3).

Correct option: (3) Campylobacter jejuni

• Structural Composition of Dairy Biofilms:
• Architecture of Biofilms:
• biofilm consists of sessile communities of microorganisms (A) adherent to stainless steel equipment surfaces, encased within an organic self-secreted extracellular polymeric substance (EPS) matrix (C).
• The matrix is composed of exopolysaccharides, structural proteins, extracellular DNA, and trapped milk residues.
• Sanitizers (B) and detergents (D) are external chemical cleaning agents used to disrupt biofilms, not structural constituents.
• Conclusion: (A) and (C) only (Option 2).

Correct option: (2) (A) and (C) only.

Matching the items of List I with List II for Microbiological changes in milk during production and processing:

The correct combination is Option 3: (A) - (III), (B) - (V), (C) - (1), (B) - (HN).

Correct option: (3) (A) - (III), (B) - (V), (C) - (1), (B) - (HN)

• Succession of Microbial Flora in Stored Raw Milk at Ambient Conditions:
• Sequential Ecological Phases:

• Bactericidal / Germicidal stage: Fresh milk resists bacterial growth due to natural indigenous inhibitors (lactoperoxidase system, lysozyme, lactoferrin).
• Development of mixed microflora: Heterogeneous acid-producing streptococci and saprophytes multiply as native inhibitors diminish.
• Growth of lactic acid bacteria: Lactococci and Lactobacilli dominate, fermenting lactose into lactic acid and depressing pH ($\lt 4.5$), coagulating casein.
• Growth of yeasts and molds: Acid-tolerant yeasts and molds (Geotrichum, Candida) utilize accumulated lactic acid, deacidifying the medium.
• Decomposing bacterial flora: Proteolytic and putrefactive bacteria (Pseudomonas, Bacillus) degrade proteins and lipids, causing spoilage.
  • Correct Sequence: (D) $\rightarrow$ (E) $\rightarrow$ (A) $\rightarrow$ (B) $\rightarrow$ (C).

• Conclusion: (D), (E), (A), (B) and (C) (Option 4).