An Overview of Klebsiella Pneumoniae

A Leading Cause of Hospital Infections

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Klebsiella pneumoniae is a contagious bacteria that can cause infections such as pneumonia and sepsis. Related symptoms can include fever and a productive cough. Infections produced by Klebsiella pneumoniae are relatively rare, and hospital settings have the the highest prevalence of cases.

Klebsiella pneumoniae may be diagnosed with imaging tests and a blood or sputum sample. This infection must be treated with antibiotics, but it is often resistant to many of them. A such, a sample may be tested for sensitivity so your medical team can identify the antibiotic most likely to be effective.

A microscopic image of Klebsiella bacteria (yellow).
. Callista Images / Getty Images


The most common infection caused by the Klebsiella pneumoniae bacteria is a urinary tract infection. However, it may also commonly cause pneumonia, an infection of the lungs that produces symptoms including fever, chills, coughing, shortness of breath, fatigue, and a sense of feeling run down.

You may experience chest discomfort due to the coughing as well. One of the characteristics of Klebsiella pneumoniae lung infection is a productive cough with thick, bloody sputum that is often described as "currant jelly sputum."

Other infections associated with Klebsiella pneumoniae include:

  • Bloodstream infection: Symptoms of a blood infection may include chills, fevers, muscle aches, fatigue, and lethargy. You may also experience changes in consciousness. Sepsis may occur as a response.
  • Meningitis: An infection of the meninges (the protective layers around the brain) can cause headaches, neck and/or back pain, fevers, a stiff neck, and fatigue. In rare instances, meningitis can cause seizures.
  • Urinary tract infection: This can cause urinary frequency, burning with urination, bladder urgency, and incontinence. It can also cause fever and abdominal pain or discomfort.
  • Wound infections, which can result in delayed wound healing, redness, pus, and pain, fevers

Klebsiella pneumoniae infections are typically characterized by symptoms that are similar to those of other infections. You may feel very sick, but it is unlikely that you or your medical team would immediately know that you have an infection associated with this bacteria until after diagnostic testing.


There are rare subspecies of Klebsiella pneumoniae which cause particularly terrible sickness:

  • Infection with Klebsiella ozaenae can result in malodorous wasting away (atrophy) of the nasal mucous membranes.
  • Klebsiella rhinoscleromatis causes rhinoscleroma, a destructive nodular inflammation of the nose and throat. 

Klebsiella pneumonia is an encapsulated organism that can evade the body's normal protective mechanisms. In addition to attacking organs such as the lungs and bladder, it also triggers an inflammatory response that increases symptoms such as fever and chills.


The Klebsiella pneumonia bacteria can naturally reside in the gut and respiratory tract of healthy individuals. Infections rarely occur in people who have a healthy immune system.

Illness, antibiotic use, or a weak immune system increase the risk. Klebsiella pneumonia is a leading cause of nosocomial infection among people of all ages, ranging from infants to older adults—that is, disease originating in the hospital.

Community-acquired Klebsiella pneumoniae can occur outside the hospital setting as community-acquired pneumonia, but this is rare. Such cases affect people who have a weak immune system, especially those who are alcohol-dependent or who have diabetes, but can also occasionally cause disease in healthy hosts.

The bacteria are spread by direct contact, typically through contamination of ventilator equipment and catheters or other types of tubing in the healthcare setting. It can also spread from person to person by touch, but it is not known to spread through the air.


Your healthcare provider will take a medical history, perform a physical exam and may use imaging to diagnose the infection (i.e. pneumonia, etc.), but a diagnosis of Klebsiella pneumoniae is based on primarily on laboratory testing.

Generally, symptoms of pneumonia, meningitis, wound infection, and any other infection caused by the organism will cause you to feel sick. Your medical evaluation will typically focus on identifying the cause of your infection and looking for signs of complications, such as an abscess.

Medical History

Your medical team will ask about fevers, nausea, cough, breathing difficulties, pain and discomfort, and your energy level and sleep. You may also be asked about risk factors and exposure to people who have had similar illnesses.

Physical Exam

Your physical exam will include an assessment of your temperature, throat, breathing sounds, and an examination of your abdomen for tenderness. Any wounds or painful skin areas will be examined for redness, swelling, or warmth.

Diagnostic Tests

The Klebsiella pneumoniae bacteria usually affects the right upper lung lobe and results in the creation of a cavity, as well as pus-producing tissue death. These cause a distinct appearance on chest X-ray, which is why your healthcare provider may order this imaging as part of the diagnostic process.

You may also need imaging tests of the abdomen, bladder, brain, or bone, depending on your symptoms and physical examination.

Your healthcare provider may also need to take samples and have them tested, depending on the suspected infection:

  • A sputum sample can detect bacterial pneumonia.
  • A blood sample may need to be tested if there is concern that you could have sepsis.
  • A lumbar puncture may be required if bacterial meningitis is suspected.

Similarly, if you have an infected wound, a small sample of the infected area can be obtained.

Samples are sent to a laboratory for a culture so the infectious organism (and its sensitivity to antibiotics) can be identified.


Klebsiella pneumoniae is treated with powerful antibiotics that may be given orally or intravenously (IV, through a vein).

Antibiotics your healthcare provider may consider include:

  • Azactam (aztreonam)
  • Quinolones
  • Third- or fourth-generation cephalosporins, such as Rocephin (ceftriaxone)
  • Carbapenems, such as Primaxin (imipenem/cilastatin)
  • Penicillins such as Zosyn (piperacillin-tazobactam)

A combination of antibiotics may be used, or a drug may be changed if sensitivity testing suggests that it will not be effective.

Treatment duration differs depending on the antibiotic, but can range from two to 14 days.

Be sure to tell your healthcare provider if you are allergic to penicillin, as you might not be able to take certain antibiotics.

Antibiotic Resistance

Klebsiella pneumoniae is a gram-negative rod encased in a thick polysaccharide capsule.

Certain strains of Klebsiella pneumoniae have evolved and are now resistant to conventional antibiotics. Bacterial resistance profiles must be checked when testing and treating the disease. For example, some strains produce beta-lactamase, an enzyme that makes them resistant to penicillins and cephalosporins. 

Bacteria that are resistant to many antibiotics are often described as "superbugs" because they are so resilient.


If you develop an abscess, you may need to have it surgically drained. This can involve a small procedure in a clinic, or it may require a surgical operation in the hospital, depending on the location of the abscess.

Typically, you would also need at least a few days of antibiotic treatment after having an abscess drained.


Prevention of this infection involves sterilizing equipment and hand washing. These procedures are taken care of in the medical setting.

If you are visiting someone in the hospital, wash your hands when you arrive and when you leave, and don't hesitate to wash them during your visit as well.

A Word From Verywell

Bacterial infections generally require treatment with antibiotics. If you have an infection caused by Klebsiella pneumoniae, it can be treated, but it may take time for your medical team to identify the right antibiotic and for the infection to be eradicated for a full recovery.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Naveed Saleh, MD, MS
Naveed Saleh, MD, MS, is a medical writer and editor covering new treatments and trending health news.