MICRO Infections of the GIT - Week 5/6 Flashcards
Transmission of H. pylori gastric ulcers
Person-to-person, ingestion of contaminated food/water.
Symptoms of gastric ulcers
o Symptoms: dyspepsia, upper abdo pain, nausea, frequent burping, bloating
NB: infections are, however, commonly asymptomatic.
Complications of H. pylori gastric ulcers
Gastric & duodenal ulcers, acute & chronic gastritis, gastric adenocarcinoma, mucosa-associated lymphoid tissue (MALT) lymphoma.
Diagnosis of H. pylori gastric ulcers
Urea breath tests, faecal H. pylori antigen testing, endoscopy w biopsy specimens, histopathology, rapid urease test of biopsy, PCR.
Transmission of non-typhoidal salmonella
o Transmission/sources: large animal reservoirs (transferred to humans via contaminated food)
Diagnosis of non-typhoidal salmonella
o Diagnosis: Culture on selective media, rapid molecular methods, blood cultures.
Treatment of non-typhoidal salmonella
o Treatment : usually self-limiting & resolves without treatment, fluid & electrolyte replacement.
Complications of non-typhoidal salmonella
Invasive infection, septicaemia
Causative agents of typhoid & paratyphoid salmonella/enteric fever
Salmonella typhi & salmonella paratyphi
Transmission of typhoid & paratyphoid salmonella/enteric fever
o Transmission: person-to-person via contaminated food/water
Diagnosis of typhoid & paratyphoid salmonella/enteric fever
o Diagnosis: stool, blood culture or culture from another body fluid/tissue
Symptoms of typhoid & paratyphoid salmonella/enteric fever
o Symptoms: fever, malaise, aches, diarrhoea & constipation, rose spots
Treatment & prevention of typhoid & paratyphoid salmonella
Antibiotics
Vaccine developed.
Causative agents of shigellosis
o Causative agents: Shigella sonnei , S. flexneri, S. boydii , S. dysenteriae.
Transmission of shigellosis
o Transmission: person-to-person via faecal-oral route (highly infectious).
Symptoms of shigellosis
o Symptoms: mild-severe gastroenteritis, initial watery diarrhoea which later worsens to contain mucous & blood , lower abdominal cramps.
Diagnosis of shigellosis
Culture or rapid molecular tests.
Treatment of shigellosis
Antibiotics for severe cases, rehydration.
Causative agents of campylobacter
Campylobacter jejuni.
Transmission of campylobacter
o Transmission: large animal reservoir via contaminated food consumption (highly infectious).
Treatment of camylobacter
Antibiotics for invasive infections.
Causative agents of cholera
V. cholerae.
Transmission of cholera
Contaminated food/water.
Symptoms of cholera
o Symptoms: severe watery non-bloody diarrhoea (rice water stools), massive fluid loss & electrolyte imbalance.
Diagnosis of cholera
o Diagnosis: culture, PCR tests.
Treatment & prevention of cholera
o Treatment: oral or IV fluids, antibiotics.
Vaccine developed.
Causative agent of C. difficile antibiotic-associated diarrhoea.
o Causative agent: C. difficile (antibiotic disruption of normal gut flora -> C. difficile multiplication).
C. difficile symptoms
o Symptoms: diarrhoea, abdominal pain, fever after antibiotic treatment.
Complications of C. difficile infection.
Toxic megacolon.
Diagnosis of C. difficile
C. difficile toxin in stools.
Treatment of C. difficile
FMT, anti-anaerobic (e.g., metronidazole) or vancomycin.
Causative agents of E. Coli
o Causative agents: enteropathogenic (EPEC), enterotoxigenic (ETEC), enterohaemorrhagic (EHEC), enteroinvasive (EIEC), enteroaggregative (EAEC).
Causative agents of staphylococcal food poisoning
S. aureus.
Transmission of staphylococcal food poisoning
Contaminated food.
Symptoms of staphylococcal food poisoning.
Vomiting or diarrhoea 1-6hrs post consumption.
Treatment of staphylococcal food poisoning
Usually self-limiting.
Bacillus cereus causative agent.
B. cereus.
Transmission of B. cereus
o Transmission: spores (present in soil/food ) survive cooking, germinate upon cooling.
Symptoms of 2 x types of bacillus cereus.
o Symptoms:
Emetic form: vomiting 15min-4hrs post consumption (due to ingestion of enterotoxin).
Diarrhoeal form: watery diarrhoea within 8-12hrs post consumption (due to production of enterotoxin in the gut).
Causative agent botulism.
C. botulinum.
Transmission of botulism.
Toxins in food (often canned food) ingested.