Klebsiella

Tribe Klebsiella

Klebsiella

• Serratia

• Enterobacter cloaca

• Hafnia alvei

• Pantoea agglomerans

Types

K. pneumoniae or Friedlander's bacillus

• • Pneumonia (CAP, HAP, VAP)

• • Red currant jelly

K. ozaenae

• • Ozaenae/ Atrophic rhinitis:

  • • Foul-smelling discharge

  • • Anosmia

K. rhinoscleromatis

• • Rhinoscleroma (woody nose/hebra nose)

K. granulomatis

• • Painless genital ulcers.

• • Also known as Donovanosis/Granuloma Inguinale (Donovan bodies).

Klebsiella Pneumonia

• Community-acquired, Hospital-acquired or Ventilator-acquired Pneumonia.

• • Chronic Obstructive Pulmonary Disease (COPD) → Superadded infection.

• • Catheter-Associated Urinary Tract Infection (CAUTI).

• • Septicemia

Important Information

Recent strain → Hyper-viscous, Hyper-virulent strain of K. Pneumoniae.

• Causes community-acquired pneumonia, meningitis and sepsis.

• Resistant to treatment.

Rhinoscleroma

Gross findings

• • Woody nose or hebra nose

• Microscopic findings

• • Mikulickz cell → Foamy cell

• • Russell body → Immunoglobulin production

Wright- Geimsa stain

Donovan bodies - Pund cells (Mononuclear cells).

• • Safety pin appearance of Donovanosis.

• • Bipolar staining

Urease Positive Organisms

(Mnemonic Punch Kiss)

• Proteus

• Ureaplasma

• Nocardia

• Cryptococcus

• Helicobacter

• Staphylococcus Saprophyticus

• Staphylococcus Epidermidis

Klebsiella Pneumoniae

Morphology

• Non-motile rod

• • Mucopolysaccharide capsule seen as a halo around the organism.

Diagnosis & Treatment

MacConkey Agar:

• Positive lactose fermenter.

• Pink color after fermentation.

  • • Pink color also seen in E. coli.

  • • Capsule presence in K. pneumoniae can be used to differentiate it from E. coli.

• Mucoid colony

• String test positivity

Biochemical Tests

• • Urease positivity: Pink color

• • IMVIC testing →--++

• • Ferments all sugars with production of acid and gas.

Treatment

• • Piperacillin + Tazobactam.

• • Extensively drug-resistant (XDR) strains → Colistin or Polymyxin (Very expensive).

• • Depends on Antibiotic Sensitivity Test

Tribe proteeae

PPA reaction: Phenylalanine acted on by phenylalanine deaminase to produce PPA.

Phenylalanine →→→(PhenylalanineDeaminase)→→→ Phenyl pyruvic acid

Proteus

• • Urease positive

• • Phenyl Pyruvic Acid (PPA) positive

Providencia

• • Urease negative

• • PPA positive

Morganella

• • Urease positive

• • PPA positive

Proteus

Pleomorphic bacillus → Any shape

• Gram negative bacilli

• Non-capsulated

• Fishy odour

Swarming Growth or Motility

Concentric growth

Seen in:

• • Proteus

• • Vibrio Parahaemolyticus

• • Vibrio Alginolyticus

• • Clostridium Tetani

• • Bacillus Cereus

• • Serratia

Inhibited by:

• • Firm agar (5-6% agar) (Normal concentration of agar is 2%).

• • Chemicals e.g. boric acid and chloral hydrate.

• • MacConkey agar due to taurocholate bile acid present.

Epidemiological typing

• To determine strains in different patients.

• Same strains: Merging of swarming.

• Different strains: Line of demarcation.

• Known as Diene's Phenomenon.

• Should not be confused with Diene stain done for Mycoplasma.

Use & Treatment for proteus

Uses of Proteus

• • Non-motile strains especially Proteus mirabilis: OX 2, 0X 19, 0X K strains used in the Weil-Felix test for rickettsia.

Treatment

• • Highly resistant bacteria.

• • Antibiotic sensitivity testing required.

• • P. Mirabilis → Ampicillin and Cephalosporin sensitive.

Salmonella

Salmonella Two types:

• • Typhoidal

• • Non-typhoidal

Kaufmann and White Scheme

• • Used to classify salmonella.

A - S. Paratyphyi A.

B

• S. Paratyphyi B.

• S. Typhimurium.

C1 - S. Paratyphyi C.

C2 - S. Muenchen.

D -

• S. Typhyi.

• S. Enteritidis.

E2 - S. Anatum.

Antigens

O (Somatic)

• • Complex made up of Polysaccharide, Protein and Lipid.

• • Boivin Antigen (Extracted from cell by Trichloroacetic Acid).

Antigenic Variation

Loss of H antigen - Loss of flagella

Loss of Vi antigen

• • V antigen (agglutinable with Vi antiserum) changes to W antigen.

• • Intermediate forms (VW).

Loss of O antigen

• • Smooth to rough variation of cell wall.

• • Loss of virulence.

New tests

• These are card based tests.

• Typhidot: IgM/IgG against outer membrane proteins.

• Dot blot: IgG against flagellar membrane proteins antigen.

Culture

Enrichment Media

• • Selenite F broth

• • Tetrathionate B broth

Selective Media

• • Xylose lysine deoxycholate (XLD).

• • Deoxycholate agar (DCA).

• • Salmonella-shigella agar (SS).

• • Hektoen enteri agar (HE).

Biochemical Tests

• • IMViC-+=+

Bacteriophage Typing

• • S. Typhi phage A, E1.

• • S. Paratyphi type 1 and 2.

Salmonella Gastroenteritis

• • Non-typhoidal salmonella.

• • Most common cause:

• • S. Typhimurium > S. Enteritidis.

• • Source: Food e.g. meat and milk.

• • Incubation period: < 24 hours.

Clinical Features

• • Fever

• • Vomiting

• • Invasive diarrhoea

Treatment

• • Usually supportive.

Salmonella septicemia

Caused by S. Choleraesuis.

Clinical features

• • Endocarditis

• • Pneumonia

• • Osteomyelitis

Fatality rate of 25%

Important Information

• Salmonella has non motile members

• • S. Gallinarum

• • S. Pullorum