The bacterium Klebsiella pneumoniae is an enterobacterium responsible for numerous and serious infections, mainly nosocomial in France. A number of strains of Klebsiella pneumoniae have developed multiple resistance to antibiotics.

Klebsiella pneumoniae, formerly known as Friedlander’s pneumobacillus, is an enterobacterium, that is, a gram-negative bacillus. It is naturally present in the intestine, in the upper airways of humans and warm-blooded animals: it is said to be a commensal bacterium.

It colonizes up to 30% of individuals in the digestive and nasopharyngeal mucous membranes. This bacterium is also found in water, soil, plants and dust (contamination by faeces). It is also a pathogen responsible for various infections:

• pneumonia,
• septicémies,
• urinary tract infections,
• intestinal infections,
• kidney disease.

In Europe, Klebsiella pneumoniae is the cause of community respiratory infections (in towns) in fragile people (alcoholics, diabetics, the elderly or those suffering from chronic respiratory diseases) and especially nosocomial infections (contracted in hospitals) in hospitalized people (pneumonia, sepsis and infections of newborns and patients in intensive care units).

The bacterium Klebsiella pneumoniae is especially recognized as responsible for nosocomial urinary and intra-abdominal infections, sepsis, pneumonia, and surgical site infections. About 8% of nosocomial infections in Europe and the United States are due to this bacterium. Klebsiella pneumoniae infections are common in neonatal departments, especially in intensive care units and in premature babies.

Symptoms of a general Klebsiella pneumoniae infection

Symptoms of a general Klebsiella pneumoniae infection are those of a severe bacterial infection:

• high fever,
• pain,
• deterioration of the general condition,
• chills.

Symptoms of a respiratory infection with Klebsiella pneumoniae

Symptoms of a respiratory infection with Klebsiella pneumoniae are usually pulmonary, with sputum and cough, in addition to fever.

Symptoms of a urinary tract infection caused by Klebsiella pneumoniae

Symptoms of a urinary tract infection with Klebsiella pneumoniae include burning and pain during urination, smelly and cloudy urine, frequent and urgent need to urinate, sometimes nausea and vomiting.

Symptoms of meningitis caused by Klebsiella pneumoniae

Symptoms of Klebsiella pneumoniae meningitis (very rare) are:

• headache,
• fever,
• altered state of consciousness,
• crises convulsives,
• septic shock.

The definitive diagnosis of a Klebsiella pneumoniae infection is based on the isolation and identification of the bacteria from samples of blood, urine, sputum, bronchial secretions or infected tissue. Bacterial identification must necessarily be accompanied by the performance of the antibiogram.

The antibiogram is a laboratory technique which makes it possible to test the sensitivity of a bacterial strain in relation to one or more antibiotics, which seems crucial for strains of Klebsiella pneumoniae which are often resistant to many antibiotics.

The bacterium Klebsiella pneumoniae like other Enterobacteriaceae is hand-carried, which means that this bacterium can be transmitted by skin contact by contaminated objects or surfaces. In the hospital, the bacteria are transmitted from one patient to another through the hands of caregivers who can carry the bacteria from one patient to another.

Out-of-hospital Klebsiella pneumoniae infections can be treated in town with a cephalosporin (eg ceftriaxone) or fluoroquinolone (eg levofloxacin).

Deep infections with Klebsiella pneumoniae are treated with injectable antibiotics. They are generally treated with broad-spectrum cephalosporins and carbapenems (imipenem, meropenem, ertapenem), or even fluoroquinolones or aminoglycosides. The choice of which antibiotic to administer can become difficult due to the acquisition of resistance.

Strains of Klebsiellia pneumoniae have developed multiple resistance to antibiotics. The World Health Organization (WHO) classifies this bacterium among the 12 “priority pathogens” resistant to antibiotics. For example, Klebsiella pneumoniae can produce an enzyme, carbapenemase, which inhibits the effect of almost all of the so-called broad spectrum β-lactam antibiotics.

In some countries, antibiotics are no longer effective for half of the patients treated for K. pneumoniae infections. Acquired resistance to antibiotics also potentially concerns other drug classes such as aminoglycosides.