During a salmonella infection, what are the first cells attacked by the salmonella?
- M cells
- Specialized fimbriae allow salmonella to bind to the M cells and invade them.
- Use a type III secretion system to induce phagocytosis (SPI-1)
- Subsequent systemic disease is caused by SPI-2 (type III as well)
What is the difference in initial replication after invasion of salmonella and Shigella?
Salmonella replicates inside vacuole because of acid tolerance response gene whereas shigella must exit the vacuole first because they lack the acid tolerance
Explain the stages of typhoid fever and the pathogen involved
- Serovars of Salmonella that cause typhoid pass through intestinal mucosa and are engulfed by macrophages – they are transported to liver, spleen, and bone marrow where they replicate
- 10-14 days after ingestion: fever, headache, aches and pains
- One week after symptoms begin; GI symptoms, bacteremic phase, colonization of the gallbladder and reinfection of intestines
What treatment should be used to salmonella?
- If enteritis then no antibiotic
- If S. typhi or S. paratyphi or disseminated infections options are fluoroquinolones, chloramphenicol, sulfa-trimethoprim, or broad spec cephalosporin
Does shigella have flagella?
What should be used to treat shigella?
Fluoroquinolone or sulfa-trimethoprim
What diseases can Klebsiella cause?
- Pneumonia (esp in alcoholics)
- Wound infections
- Soft tissue infections
- Liver abscesses in alcoholics
- Granulomatous disease of nose or genitals or inguinal region
What are Donovan bodies?
- Appearance of small rods in the cytoplasm of histiocytes, PMNs and plasma cells
- Characteristic of Klebsiella granulomatis
- Important because K granuolomatis doesn’t grow on media so must be identified from donovan bodies
Does Klebsiella pneumonia ferment lactose? What color will they be on MacConkey agar?
What is used to treat Klebsiella?
Tetracycline, erythromycin, sulfa-trimethoprim
What is characteristic of Proteus motility?
- Proteus can be either “swimmers” with 8-10 flagella or swarmers, with Peritrichous flagella
- Swarmers make concentric rings on agar plate
What diseases are associated with proteus?
- UTI mostly, also;
- Skin infections
- Respiratory infections
- Wound infections
What would labs for proteus show? (lactose, motility, urease)
- Lactose negative
- Swarming motility
- Urease +
What drugs can and can not be used to treat proteus?
- Trimethoprim, cephalosporins, Fluoroquinolones,
- Not good:
- Tigecycline (unless with amikacin)
- *be sure to change catheter before treatment b/c biofilm on catheter