Proteus

Question 1

What 3 Proteus species are of veterinary importance?

Answer 1

1. P. mirabilis
2. P. penneri
3. P. vulgaris

Question 2

What fermentation does Proteus undergo? How does it grow in TSI media? How does it respond to urease tests?

Answer 2

lactose non-fermenter

produces H2S gas

urease positive —> characteristic ammonia smell resulting from converting urea into ammonia

Question 3

What causes the characteristic swarming pattern of Proteus on media?

Answer 3

highly motile with peritrichous flagella —> swarming (whole population movement)

Question 4

How can identical and different strains of Proteus be differentiated when plated on media?

Answer 4

formation of boundaries - Dienes lines

(3 strains in pic)

Question 5

How does Proteus move in agar media/solid surfaces? Liquid media?

Answer 5

SOLID: swarming motility

LIQUID: swimming motility of multicellular rafts of elongated, hyperflagellated swarmer cells with the ability to move rapidly

Question 6

What 3 characteristics contribute to the serotype diversity of Proteus?

Answer 6

1. O antigens (LPS)
2. flagellin variation
3. ZapA metalloprotease
   - all for immune evasion

(80 O-antigenic serogroups)

Question 7

What is the host range of Proteus?

Answer 7

all vertebrates

Question 8

What are the 2 main habitats of Proteus?

Answer 8

1. human/animal GI tract, vulva, vagina, skin, and oral mucosa
2. survives in the environment in feces, sewage, manure, polluted soil, water, and plants
   - indicator of fecal pollution in water and soil

Question 9

What 6 surface structures of Proteus contribute to its virulence factors?

Answer 9

1. fimbriae - adhesion, biofilm formation, autoaggregation, bladder and kidney colonization
2. flagella - swimming, swarming (ascend into kidneys)
3. LPS - endotoxin
4. O and capsular polysaccharides - facilitates swarming, kidney stones, immunoavoidance, biofilm formation, sero-specificity
5. biofilm - self protection
6. invasin - internalzation into host cells

Question 10

What 3 enzymes of Proteus contribute to its virulent factors?

Answer 10

1. urease - urine pH elevation, kidney stone formation, crystalline biofilm production, nutrition/host sensing
2. protease - antibodies degradation
3. deaminase - alpha-ketoacid siderophore production, iron acquisition

Question 11

What 4 toxins/proteins do Proteus produce to contribute to its virulence factor?

Answer 11

1. hemolysins - cytotoxicity
2. Proteus toxin agglutinin (Pta) - cell-cell aggregation, cytotoxicity
3. zinc and phosphate transport systems
4. siderophores - metal scavenging for iron and zinc essential for growth

Question 12

What are the 2 major virulence factors that cause disease in Proteus infection?

Answer 12

1. flagella elongation
2. urease production

Question 13

Why is the presence of urease considered Proteus’ most potent virulence factor?

Answer 13

converts urea into ammonia, which changes the pH of urine to a more alkaline one, promoting kidney stone formation

• kidney stone formation (calculi, struvite) and catheter blockage = major complications

Question 14

How do the species of Proteus affect disease presentation?

Answer 14

P. mirabilis —> struvite renal stones (urolithiasis), UTI

P. penneri —> nosocomial UTI, sepsis

P. vulgaris —> nosocomial UTI, sepsis

Question 15

What virulence factors contribute to disease caused by Proteus?

Answer 15

PYELONEPHRITIS - fimbriae, AipA autotransporter, urease, IgA protease ZapA, Pta toxin, zinc uptake, hemolysin, flagella

CYSTITIS - fimbriae, urease, IgA protease ZapA, Pta toxin, zinc uptake, flagella

UROLITHIASIS - urease

CATHETER COLONIZATION/BLOCKAGE - urease, swarming motility, fimbriae

Question 16

What is the dominant species of Proteus causing clinical disease? What are 4 common presentations?

Answer 16

P. mirabilis (90%)

1. ulcerative lesions in GI tract
2. septicemia with supperative and necrotic lesions
3. septic thrombi and infarction of many organs, mainly kidney
4. nephritis and pyelonephritis characterized by abscessation and scarring (struvite renal stones make up of magnesium, ammonium, and phosphate)

Question 17

What disease is caused by Proteus vulgaris and Proteus penneri?

Answer 17

occasionally cause urinary tract disease

Question 18

Proteus infection at various anatomical locations:

Answer 18

Question 19

How can Proteus affect food?

Answer 19

food spoilage of raw meat, seafood, vegetables, and canned food
- grows in milk = curds, liquefies

Question 20

What are the main biochemical tests used to identify Proteus?

Answer 20

• Gram - rods
• oxidase -
• MacConkey agar lactose -
• H2S gas on TSI +
• motility + with swimming/swarming
• urease +