Statement (I) is correct: Coxiella burnetii (the Q-fever agent) is the most heat-resistant non-spore-forming pathogen in raw milk, and modern pasteurization standards ($63^\circ\text{C}/30\text{ min}$ LTLT and $72^\circ\text{C}/15\text{ s}$ HTST) are specifically calibrated to destroy it. Statement (II) is incorrect: proper pasteurization thermally denatures and completely inactives alkaline phosphatase, resulting in a NEGATIVE alkaline phosphatase test (a positive test indicates raw milk under-pasteurization or post-process contamination).

On XLD agar, Salmonella initially ferments xylose, but rapidly decarboxylates lysine, causing the pH to revert to alkaline and turning the phenol red indicator red/pink. Furthermore, Salmonella produces hydrogen sulfide ($\text{H}_2\text{S}$) from sodium thiosulfate, which reacts with ferric ammonium citrate to form black ferric sulfide precipitates, producing characteristic red colonies with glossy black centers.

Classification of foodborne illnesses into infections, intoxications, and toxi-infections:

• Vibrio parahaemolyticus causes true invasive foodborne infection through intestinal mucosal adherence and invasion.
• Yersinia enterocolitica is an invasive bacterial infection causing enteritis and mesenteric lymphadenitis.
• Clostridium botulinum causes pure foodborne intoxication resulting from pre-formed botulinum neurotoxin ingested in food.
• Clostridium perfringens (Type A) causes foodborne toxi-infection (toxicoinfection). Large numbers of viable vegetative cells ($\gt 10^6\text{ cfu/g}$) are ingested through contaminated cooked meat or dairy foods, survive gastric passage, and sporulate in the small intestine, releasing heat-labile Clostridium perfringens enterotoxin (CPE) into the gut lumen during the sporangial lysis step of sporulation.

Pathogenic syndromes caused by foodborne bacterial pathogens:

• Salmonella typhi causes systemic enteric typhoid fever.
• Bacillus cereus causes two distinct foodborne poisoning syndromes:
• Emetic Syndrome: caused by ingestion of the pre-formed, highly heat-stable, cyclic dodecadepsipeptide toxin called cereulide, characterized by rapid onset of intense nausea and vomiting (emesis) within 0.5 to 5 hours of ingestion (frequently linked to starchy foods, cooked rice, and dairy puddings/custards).
• Diarrheal Syndrome: caused by heat-labile enterotoxins (Hbl, Nhe) formed in the small intestine, causing watery diarrhea within 8-16 hours.
• Clostridium perfringens causes diarrheal enteritis.
• Escherichia coli O157:H7 causes hemorrhagic colitis and hemolytic uremic syndrome (HUS).