Bacte- Proteus

Proteus mirabilis was first discovered by a German pathologist named _______

Gustav Hauser

proteus spp

1. P. vulgaris

2. p. mirabilis

3. p. rettgeri

4. p. penneri

5. p. hauseri

6. p. myxofaciens

what are the most frequently isolated organisms in humans?

P. mirabilis and P. vulgaris

is a Gram-negative, facultatively anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity

P. mirabilis

is a chemoheterotrophic bacterium and possesses peritrichous flagella, making it actively motile.

P. vulgaris

is a cyclic, multicellular behavior allowing rapid migration of “rafts” of P. mirabilis cells over solid surfaces

swarming

Proteus mirabilis is rapid urease positive as evidenced by the _____ color of the media.

pink

true/false

E. coli is urease negative

true

a differential medium that tests the ability of an organism to produce an exoenzyme

urease broth

it hydrolyzes urea to ammonia and carbon dioxide

urease

phenol red turns _______ in an acidic environment

yellow

phenol red turns _______ in an alkali environment

fuchsia

If the urea in the broth is degraded and ammonia is produced, an alkaline environment is created, and the media turns

pink

In liquid medium, _________ exists as a short (1.5 to 2 μm) motile rod with peritrichous flagella

P. mirabilis

two unusual characteristics of P. mirabilis flagella

1. all genes encoding flagellar component are found within a single 54 kb locus in the chromosome

2. P. mirabilis encodes two flagellins, FlaA and FlaB, which comprise the whip structure of the flagellum.

it is a protein that exhibits bright green fluorescence when exposed to light in the blue to ultraviolet range

green fluorescent protein (GFP)

isolated from the center of the bull'seye

short form swimmer

taken from the leading edge of the outermost terrace fluoresced bright green when bacteria were visualized by laser-scanning confocal microscopy

elongated swarmer cells

both swimmer and elongated swarmer cells can be easily detected by

fluorescence miscroscopy

Proteus mirabilis infection occurs in the following conditions:

1. longer duration of catheterization

2. improper catheter cleaning or care

3. underlying illness

4. lack of availability of systemic antibiotics

is the most frequent Proteus species associated with urinary tract infections

P. mirabilis

_______ are more often resistant to ampicillin

indole positive proteus (like P. vulgaris)

are part of the human intestinal flora and can cause infection upon leaving this location.

proteus spp

proteus spp are transmitted through

1. contaminated catheters (urinary catherters)

2. accidental parenteral inoculation

incidence of P. mirabilis

1-10% of all urinary tract infections

the highest incidence of P. mirabilis CAUTI occurs in ______ during long term catheterization

elderly patients

anitgenic characteristic

1. thermostable o (somatic) antigen

2. thermostable h (flagellar) antigen

virulence factor

1. potent urease that catalyzes formation of ammonia from urea and leads to urinary stone formation

2. pore-forming hemolysin

3. ZapA metalloprotease which cleaves both immunoglobulin IgG and IgA

4. a capsular polysaccharide

5. four distinct fimbrial types

6. peritrichous flagella for swimming and swarming motility

In the urinary tract alkaline pH leads to precipitation of _____and _________

calcium and magnesium ions

urinary stones are composed of

1. magnesium ammonium phosphate (struvite)

2. calcium phosphate (apatite)

Concepts of Proteus mirabilis pathogenesis during urinary tract infection (UTI)

1. adherence

2. urease

3. motility

4. metabolism

5. metal scavenging

6. toxins

7. biofilm formation

8. immune evasion

9. virulence regulation

10. type 6 secretion system (T6SS)

Adherence is mediated by

1. chaperone-usher fimbriae

2. autotransporter adhesins

involved in stones, crystalline biofilms, and possibly nutrition or host sensing.

urease

essentiall metals for the growth of P. mirabilis

iron and zinc

this can include antibody and antimicrobial peptide degradation, polymyxin resistance, lipopolysaccharide (LPS) variation, and physical obstruction of phagocytosis

immune evasion

involved in self-recognition; unknown role during UTI.

type 6 secretion system (T6SS)

this enzyme is an active target of investigation to identify clinically useful inhibitors.

urease

Since the ability of P. mirabilis to generate urinary stones and crystalline biofilms is dependent upon alkaline pH, another approach to prevent catheter blockage is to

acidify the urine

mineral nucleation can be inhibited by reducing mineral concentration in the urine, i.e., by

increasing fluid intake

a lower nucleation pH is associated with

increased stone formation

P. mirabilis is capable of causing symptomatic infections of the urinary tract including _______ and ______

cystitis and pyelonephritis

P. mirabilis is capable of causing symptomatic infections of the urinary tract including cystitis and pyelonephritis and is present in cases of ___________, particularly in the elderly and patients with type 2 diabetes.

asymptomatic bacterinuria

cystitis and pyelonephritis are infections that can also cause ______ and progress to potenitally life threatening ______

bacteremia; urosepsis

it is the most common infection acquired in hospitals and other health care facilities

C-UTI

Recurrent urinary tract infections with a urease-producing organism (mostly Proteus species) results in formation of ________ in the kidney.

staghorn calculi

laboratory diagnosis

1. gram negative

2. non- spore forming rods

3. facultative anaerobes

4. urease positive (strong)

5. oxidase test negative

6. nitrates are reduced to nitries

7. ferments glucose but does not ferment lactose

8. deaminates phenylalanine to phenylpyruvic acid

for UTI _____ sample is used

midstream urine

for pyogenic lesions _______ sample is used

pus aspirate

what media are commonly used for pus and urine sample

blood agar and mcConkey agar

true/false

proteus spp are nitrite reduction test positive

true

true/false

proteus spp are oxidase test negative

true

this test is used to determine the ability of the bacteria to ferment sugars and to produce hydrogen sulfide (H2S) or other gases

Triple Sugar Iron (TSI) Test

it is used to determine the ability of bacteria to convert trytophan into indole

IMViC test 1 indole test

P. mirabilis can be differentiated fro mp. vulgaris by

indole test (P. merabilis: negative, green; P. vulgaris: positive, pink)

Swarms from different strains, make a visible boundary in the form of a cell-free zone called ________, which is used to distinguish clinical isolates

Dienes line

when two different strains of Proteus sppp inoculated at different places of same non-inhibitory medium (blood agar), swarming of the two strains remains separated by a narrow visible furrow. However, in case of two identical strains of Proteus, swarming of two colonies coalesce without signs of demarcation. Such condition is called:

Dienes phenomenon

Swarming properties of Proteus presents problems in the diagnostic laboratory when mixed growth is present in which Proteus is one of the isolate. Several methods have been used to inhibit swarming

1. increase agar concentration (6% instead of 1-2%)

2. Incorporation of chloral hydrate (1:500), sodium azide (1:500), boric acid (1:1000) in the medium

3. Using Cysteine Lactose Electrolyte Deficient (CLED) as a sole medium instead of MacConkey Agar and Blood Agar for the processing of urine samples.

4. Addition of Teepol (a surface active agent)

5. The addition of growth inhibitors (like sulphomides)

6. the prsence of bile salts in the medium

ti is a type of agglutination test in which patients serum is tested for agglutinins to O antigen of certain non-motile proteus and rickttsial strains (OX19, OX2, OXK)

Weil Felix Reaction

Treatment Uncomplicated UTIs in women can be treated on an outpatient basis with

1. orl quinolone for 3 days or

2. trimethoprim/sulfamethoxazole (TMP?SMZ) for 3 days

Complicated UTIs in men and women can be treated with

10- to 21-day course of oral therapy in the same manner as for hospitalized patients as long as the follow-up is adequate)

prevention

vaccination