Inflam. Bacterial Diarrheal + H Pylori Flashcards
What are the 4 inflammatory Bacterial Diarrheal pathogens ?
Campylobacter
Salmonella
Shigella
Yersinia
Salmonella Bacteriology:
- Gram stain?
- Motility?
- lactose ferementer?
- what agars can be used?
- What is the only strain with a capsule?
- what are the serotypes
Gram Negative Rod
Motile —- Flagella
Lactose Negative on MacConkey agar
§ Hectoen Enteric Agar -- non lactose fermenters are blue ; H2S centers = black
Serotypes: O and H (just like E. Coli)
S. typhi – the only strain with a capsule (Vi Capsule)
Describe the nomenclature of salmonella?
- what is the pathogenic species?
what is the pathogenic subspecies?
what animals are implicated with harboring salmonella?
almonella Enterica: which has 6 subspecies
□ Subspecies: S. enterica - 99.5% of human pathogens
® Many different serotypes
□ The other 5 subspeices reside in cold blooded animals
Turtles
Non Typhoid Salmonella:
- How is it transmitted?
- Presentation?
- treatment?
- what about the immune response?
- transmitted via Ingestion; fecal/oral (chickens, contamination)
- Presentation: watery, mucoid, bloody DIARRHEA ; abd pain; fever
- No Abx are indicated
- Robust inflammation contains the pathogen, but at the expense of inflammatory diarrhea
Typhoid Salmonella
- what is this also known as?
- what serotypes cause it ?
- Where is it carried and why?
- what is its presentation?
- what is a specific symptom?
- what are some complications?
- Treatment?
- Typhoid fever
- S. typhi, S. paratyphi
- S. typhi is encapsulated
- carried in the gall bladder; bile allows for biofilm formation; associated with stones
– Presentation: NO DIARRHEA,
febrile, malaise, HA, - Specific Sx; Rose Spots
- Complications: intestinal hemorrhage, sespsis, abscess, pericarditis,
Treatment: abx, but there is a lot of resistance
describe the difference in the immune response between NTS and Typhoid Salmonella?
NTS – does not evade the immune repsonse (LPS - TLR 4; Flagella - TLR 5)
Enteric inflammation and diarrhea
Typhoid: Evades the immune response and becomes systemic illness
- Capsule; LPS evades TLR4
- Flagella regulation – evades TLR5
Describe some Virulence Factors of Salmonella?
SPI (salmonella pathogenicity islands)
Type 3 secretions (hijack actin cytoskeleton; prevent fusion with the lysosome)
Utilization of IRON: produces Salmochellin (a unique siderophore) which cannot be bound by LipoCalin2
Describe the Bacteriology of Shigella:
- what family is it in?
- Gram negative for positive?
- shape
- Motility?
- Lactose fermenting?
Family Enterobacteriaceae
GNR
Non Lactose on MacConkey Agar
Non Motile
name the 4 species of Shigella which are pathogenic to humans?
which one produces the virulent toxin?
What is unique about Infectious dose?
S. sonnei - common in the US; causes traveler’s diarrhea
S. Flexneri - most common world wide
S. Dysenteriae: most severe, produces Shiga Toxi; causes outbreaks and epidemics
S. Boydii – least common
ALL ARE ADAPTED TO HUMAN HOST
Very Low infectious dose:
ID 10-100 CFU
Clinical Shigellosis: Transmission Symptoms Describe the stool Complications
- Fecal/oral
- Fever, malaise, watery diarrhea, cramps
- Some patient’s get Dysentery (scant stool with gross blood ;
- Complications:
- Persistent Diarrhea
- Protein loss; malnutrition; cognitive defects
- Colitis
- Rectal prolapse
- Reactive Arthritis (Reiter’s Disease)
What is Reactive arthritis?
- aka ?
- triad of symptoms
- Reiter’s Disease
- Arthritis, urethritis, conjunctivitis
Pathogenesis of Shigella:
- where does it invade intially?
- how does it get from cell to cell?
- invades M cells
- Apoptosis of macropahges
- induces inflammatory response
- Reinvade epithelial cells from the basolateral side
- utilizes “rocket propulsion” of actin polymerization to invade neighboring cells
- Virulence Factors of Shigella
- what was gained?
- what was lost
Pathogenicity Islands
gained; PLasmid with Type 3 secretions; enterotoxins
Loss: CadA gene (makes cadaverine; which inhibits shigella enterotoxns)
Treatment of Shigella Infection
Hydration
Abx are indicated but MD resistance is very common
What’s so special about S. Dystenteriae?
Produces shiga toxin
more virulent
cleaves 28S rRNA
HUS
Yersinea
- Bacteriology:
- gram stain and shape
- motility ?
- Enterobacteriaceae family
- Gram Negative Rod
- Flagella (y. enterocolitic, y. pseudotuberculosis)
Yersiniea – what three species cause human disease?
what are the assocaited diseases ?
Y. Pestis – bubonic plague
Y. Enterocolitical – inflammatory bloody diarrhea associated with mesenteric LNs
Y. psuedotuberculosis - gastroenteritis, mesenteric adenitis,
Yersinia – Pathogenesis:
Presentation is similar to what other disease ?
- Also invade via M cells; move to BL side; paralyze macrophages
- Invade epithelial cells from BL side;
- Spread cell to cell
- Supression of TNF and phagocytosis
- Reside in Peyer’ patches in the gut
- Presentation: Ileal and mesenteric Abscesses
Presentation similar to appendicitis
• Yersinia enterocolitica
- incidence relative to shigella and salmonella ?
- What animal products is it associated with?
-
- Much lower incidence than shigella and salmonella
- associated with pork products
Virulence factors of Yersinia:
Type 3 secretions
CAMPYLOBACTER Jejuni
- Epi: what does it commonly cause
- what are its reservoirs
- what foods are implicated?
Common cause of diarrhea in the US and Worldwide
Traveler’s Diarrhea
Raw- unpasteurized milk
Under cooked chicken
Campylobacater Jejuni - - Bacteriology - gram stain shape
- What is its aero-tolerance?
- Motile?
Gram negative curved shape
Microaerophilic: must be grown in low O2 conditions
Flagellated
Campylobacater Jejuni
- disease manifestations
C jejuni Enteritis
Symptoms: Fever, abdominal pain, diarrhea
Treatment: Abx would work If taken early on
Oral rehydration
C Jejuni Guillain Barre Syndrome
antigens made to LOS surface antigens on campy cross react with gangliosides of the nervous system
Relation to IBD (may be due to change in the microflora)
pathogenesis of Campylobacter:
- Invasion
- Inflammation
- Evades immune system
invasion via spiral shape and flagella
Induces inflammation (IL-8)
Evades Immune system (aletered flagella avoid TLR5)
Helicobacter Pylori
- Bacteriology:
- gram stain
Shape
motile?
aerotolerance?
where does it reside?
• Gram Negative
○ Spiral Shaped
• Microaerophilic --
Flagella
• Organism of the stomach
What percentage of people are colonized with H pylori and it what countries?
- what percentage of people devleop disease?
- What are the disease manifestations?
- 50% of persons in developed countries have been colonized
- 90% of persons in devleoping nations have been colonized
• 50% of colonized individuals will manifest disease ○ Gastritis ○ Ulcers ○ Adenocarcinoma ○ MALT lymphoma
Describe some Vital virulence Factors for H. Pylori?
- Flagella and Spiral Shape
- UREASE – converts urea to ammonia which drops the pH
- VacA – pore forming
- CagA — increased risk of cancer
- Type 4 secretions:
H Pylori Diagnosis:
Endoscopy: Histology, culture bx, urease test on bx
Non Endoscopic:
serology
Breath test
Treatment for H pylori
• Triple Drug therapy regimens are most effective
○ Clarithro, omeprazole, amoxcillin
• No Vaccine
