Food Microbiology & Biotechnology

Etiology of foodborne infections:

• Shigellosis (bacillary dysentery) is a severe bacterial infection of the intestines caused by Gram-negative bacteria of the genus Shigella (S. dysenteriae, S. flexneri).
• Toxoplasmosis is caused by the intracellular protozoan parasite Toxoplasma gondii.
• Trichinellosis is caused by the parasitic nematode roundworm Trichinella spiralis.
• Cysticercosis is caused by the larval tissue cysts of the tapeworm Taenia solium.

Regulatory thresholds for patulin mycotoxin in fruit juices:

• $10\ \mu\text{g/kg}$ is the strict regulatory limit for infant foods and baby purees.
• Under Codex Alimentarius and FSSAI (Contaminants, Toxins and Residues) Regulations, the maximum permissible limit for patulin (a toxic mycotoxin produced primarily by Penicillium expansum in rotting apples) in apple juice and apple juice ingredients is $50\ \mu\text{g/kg}$ ($50\text{ ppb}$).
• $100\ \mu\text{g/kg}$ exceeds statutory safety tolerances.
• $200\ \mu\text{g/kg}$ is dangerously high and illegal under food safety standards.

Taenia saginata (the beef tapeworm) is an obligate human cestode parasite. Cattle ingest eggs from contaminated pasture, and the oncospheres penetrate the intestinal wall and encyst as Cysticercus bovis in skeletal and cardiac muscle (measly beef). Consumption of raw or undercooked measly beef infects humans, causing intestinal taeniasis. Taenia solium is the pork tapeworm, while Trichinella spiralis is a nematode found in swine and game meat.

Option analysis:

• Taenia saginata: Correct, beef tapeworm encysting in cattle and causing taeniasis in humans.
• Toxoplasma gondii: Protozoan parasite with cats as definitive host.
• Balantidium coli: Ciliated intestinal protozoan parasite, not a tapeworm.
• Trichinella spiralis: Parasitic nematode (roundworm) associated with undercooked pork, not cattle tapeworm.