Q.66 Food-borne bacteria that cause acute bacterial vomiting and diarrhea:
- Shigella sp.
- Salmonella sp.
- Pseudomonas aeruginosa
- Clostridium tetani
- Yersinia enterocolitica
Choose the correct answer from the options given below:
- A, B, D only
- A, B, C only
- C, D, E only
- E, A, B only
E, A, B only (Shigella sp., Salmonella sp., Yersinia enterocolitica) are correct food-borne bacteria causing acute vomiting and diarrhea.
Statement Analysis
A. Shigella sp. – TRUE: Causes shigellosis via fecal-oral route (contaminated food/water). Symptoms: bloody diarrhea, vomiting, fever, cramps (1-2 days incubation). Low infectious dose (10-100 bacteria).
B. Salmonella sp. – TRUE: Major foodborne pathogen (poultry, eggs, produce). Salmonellosis: acute diarrhea, vomiting, fever, abdominal cramps (12-72 hr incubation). 1.35M US cases/year.
C. Pseudomonas aeruginosa – FALSE: Opportunistic pathogen causing pneumonia, UTIs, wound infections in immunocompromised/hospitalized—not foodborne gastroenteritis. Rare food transmission.
D. Clostridium tetani – FALSE: Tetanus (lockjaw) via wounds/soil spores, not foodborne. Neurotoxin blocks inhibitory neurons—no vomiting/diarrhea.
E. Yersinia enterocolitica – TRUE: “Pseudo-appendicitis” bacterium in pork, milk. Acute watery/bloody diarrhea, vomiting, fever, abdominal pain (24-48 hr incubation). Common in children.
Option Breakdown
Option Evaluation Reason E, A, B only Correct All three verified foodborne enteropathogens causing acute GI symptoms. A, B, D only Incorrect C. tetani causes tetanus, not food poisoning. A, B, C only Incorrect Pseudomonas not foodborne gastroenteritis agent. C, D, E only Incorrect C,D irrelevant to foodborne illness. Foodborne bacteria Shigella Salmonella Yersinia cause acute vomiting and diarrhea, distinguishing them from wound pathogens like Clostridium tetani—essential NEET microbiology differentiation.
Shigella Pathogenesis (Statement A)
Mechanism: Shiga toxin + epithelial invasion → bloody mucoid diarrhea (dysentery). 10 organisms ID₅₀ via M-cells. Incubation 12-50 hr. Foodborne via salads, vegetables.
Salmonella Gastroenteritis (Statement B)
Non-typhoidal: S. Enteritidis, Typhimurium → self-limiting diarrhea (2-7 days). Fimbriae adhesion + T3SS effectors trigger inflammation. Poultry/eggs primary vectors.
Yersinia Enterocolitica Enteritis (Statement E)
Cold enrichment (4°C growth). Yops (Yersinia outer proteins) injected via T3SS suppress phagocytosis. Pork chitterlings classic vehicle. Mimics appendicitis.
Key Distractors Explained
Pseudomonas aeruginosa (C): Cystic fibrosis pneumonia, catheter UTIs, burn wound sepsis. Not enteric.
Clostridium tetani (D): Tetanospasmin blocks glycine/GABA → opisthotonus, risus sardonicus. Wound contamination only.Clinical Differentiation Table
Bacterium Incubation Stool Character Food Vehicle Complications Shigella 1-2 days Bloody/mucoid Produce HUS (5%) Salmonella 12-72 hr Watery Poultry/eggs Reactive arthritis Yersinia 24-48 hr Watery/bloody Pork Appendicitis mimic Pseudomonas N/A N/A None Pneumonia NEET Strategy
E,A,B only tests foodborne enteropathogen vs opportunistic/wound pathogen distinction. Shigella-Salmonella-Yersinia triad vs Pseudomonas-C.tetani distractors.
