[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Enterobacterales](https://durgical.com/en/microbiology/groups/enterobacterales/) › Klebsiella pneumoniae

[Microbiology](https://durgical.com/en/microbiology/) · [Enterobacterales](https://durgical.com/en/microbiology/groups/enterobacterales/)

# Klebsiella pneumoniae

- Bacterium
- Gram-negative
- Contact
- Exam priority: medium

A gut bacterium with a thick capsule. It causes pneumonia, urinary infection and sepsis in hospitals; many strains resist key antibiotics.

Updated 2026-11-01

## Key points

- Very mucoid colonies from its large capsule.
- "Currant jelly" sputum pneumonia in people with alcohol use disorder or diabetes.
- Intrinsically resistant to ampicillin.
- KPC: a plasmid carbapenemase that inactivates almost all beta-lactams, carbapenems included.
- Colombia: KPC endemic since the first reports in Medellín.

## At a glance

**Gram**
Gram-negative

**Shape**
Rod

**Oxygen**
Facultative anaerobe

**Family**
Enterobacteriaceae

**Stain**
Gram: red encapsulated rods

## Morphology

- Non-motile Gram-negative rod with a large polysaccharide capsule
- Lactose fermenter: pink, very mucoid colonies on MacConkey
- Urease-positive, oxidase-negative

## Transmission

- Person-to-person contact, mainly through contaminated hands in hospital
- Contaminated equipment: ventilators, IV catheters and urinary catheters
- Not airborne
- Contact (on top of standard) for carbapenem-resistant strains

**Reservoir:** Human gut; Hospital environment, water and soil

### Isolation precautions

What the care team adds to standard precautions.

**Contact**
Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing.

## Virulence factors

- Capsule: blocks phagocytosis; hypermucoviscous strains are more aggressive
- LPS: sepsis
- Intrinsic ampicillin resistance (SHV-1 beta-lactamase)
- Plasmids carrying ESBL and carbapenemases (KPC, NDM) that pass to other bacteria

## Diseases it causes

- Pneumonia, classic in people with alcohol use disorder or diabetes, and ventilator-associated pneumonia [Community-acquired pneumonia →](https://durgical.com/en/conditions/community-acquired-pneumonia/)
- Urinary infection, especially catheter-associated [Urinary tract infection (acute cystitis) →](https://durgical.com/en/conditions/urinary-tract-infection/)
- Bacteremia and sepsis; also liver abscess and surgical wound infection [Sepsis and septic shock →](https://durgical.com/en/conditions/sepsis-and-septic-shock/)

## Clinical picture

- Pneumonia with thick bloody sputum ("currant jelly"), often upper lobe and cavitating

## Diagnosis

- Culture of sputum, urine or blood: pink mucoid colonies
- Susceptibility testing with screening for ESBL and carbapenemases (phenotypic tests and PCR for KPC, NDM and others)

## Treatment

Guided by the antibiogram. Susceptible strains: third-generation cephalosporins; ESBL producers: carbapenems; KPC producers: newer beta-lactamase inhibitor combinations such as ceftazidime-avibactam, or combination regimens chosen with infectious diseases.

Drug class only; doses and regimens are set by the clinician from the current guideline.

In Pharmacology:

- [Ceftriaxone](https://durgical.com/en/pharmacology/ceftriaxone/)
- [Meropenem](https://durgical.com/en/pharmacology/meropenem/)
- [Ceftazidime + avibactam](https://durgical.com/en/pharmacology/ceftazidime-avibactam/)
- [Beta-lactams](https://durgical.com/en/pharmacology/classes/beta-lactams/)

## Prevention

- Hand hygiene and contact precautions for resistant strains
- Early removal of catheters and ventilators
- Careful antibiotic use (stewardship programs)
- Carrier screening during outbreaks

## In Colombia

Colombia reported South America's first carbapenemase KPC-producing K. pneumoniae, from Medellín hospitals (2006), and KPC is now endemic in its hospitals. Healthcare-associated infections and antibiotic consumption are INS surveillance events.

## Memory aid

"Klebsiella wears a thick coat and carries the hospital master key": the capsule protects it and KPC unlocks even the last door, the carbapenems.

## Test yourself

Think of the answer, then tap the question to see it.

## What do Klebsiella pneumoniae colonies look like, and why?

Pink and very mucoid, from its large polysaccharide capsule and lactose fermentation.

## Which classic pneumonia is described in patients with alcohol use disorder?

Klebsiella pneumonia, with thick bloody "currant jelly" sputum and cavitation.

## What is KPC?

A plasmid-encoded carbapenemase of Klebsiella pneumoniae that destroys almost all beta-lactams, carbapenems included.

## Which isolation precaution is used for carbapenem-resistant Enterobacterales?

Contact precautions, on top of standard.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/microbiology/klebsiella-pneumoniae/)

## Related

- [Escherichia coli](https://durgical.com/en/microbiology/escherichia-coli/)
- [Acinetobacter baumannii](https://durgical.com/en/microbiology/acinetobacter-baumannii/)
- [Pseudomonas aeruginosa](https://durgical.com/en/microbiology/pseudomonas-aeruginosa/)

## Related conditions

- [Community-acquired pneumonia](https://durgical.com/en/conditions/community-acquired-pneumonia/)
- [Urinary tract infection (acute cystitis)](https://durgical.com/en/conditions/urinary-tract-infection/)
- [Sepsis and septic shock](https://durgical.com/en/conditions/sepsis-and-septic-shock/)

## What the colours mean

**Gram-positive**
Thick peptidoglycan wall: stains purple.

**Gram-negative**
Thin wall with an outer membrane: stains pink.

**Acid-fast**
Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain.

**Contact**
Gown and gloves; dedicated equipment. For C. difficile, soap-and-water hand washing.

**Droplet**
Surgical mask within about a metre; single room.

**Airborne**
N95 respirator and a negative-pressure room.

[← Back to the group: Enterobacterales](https://durgical.com/en/microbiology/groups/enterobacterales/)

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [About Klebsiella](https://www.cdc.gov/klebsiella/about/index.html) (CDC, 2025); [First Detection of the Plasmid-Mediated Class A Carbapenemase KPC-2 in Clinical Isolates of Klebsiella pneumoniae from South America](https://pmc.ncbi.nlm.nih.gov/articles/PMC1538657) (Antimicrobial Agents and Chemotherapy (PMC), 2006); [Epidemiological Alert: Emergence and increase of new combinations of carbapenemases in Enterobacterales in Latin America and the Caribbean - 22 October 2021](https://www.paho.org/en/documents/epidemiological-alert-emergence-and-increase-new-combinations-carbapenemases) (PAHO, 2021); [Antimicrobial resistance](https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance) (WHO, 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

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Source: https://durgical.com/en/microbiology/klebsiella-pneumoniae/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/klebsiella-pneumoniae/