Klebsiella is a gram-negative, rod shaped and non-motile bacterium of the family Enterobacteriaceae. Group of bacteria belonging to this taxonomic family contributes to the natural flora of humans and animals. But, when they are present outside the gut (i.e. alimentary canal between the stomach and anus), these bacteria may cause certain lethal infections in humans. The term 'Klebsiella' was coined in honor of the German pathologist, Edwin Klebs who had done significant research in the field of infectious diseases. Here, we shall have a discussion about Klebsiella pneumoniae, an important strain of the Klebsiella genus.
Amongst all the species of Klebsiella, K. pneumoniae is a widely studied strain. According to findings, it is encapsulated, meaning a polysaccharide layer is present outside the cell-wall of this bacterium. It can synthesize ATP (adenosine triphosphate) by aerobic respiration, but can also switch on to anaerobic fermentation for deriving energy. Thus, it is a facultative anaerobic, and has a characteristic feature of becoming both aerobic and anaerobic depending upon the situation.
As far as isolation of K. pneumoniae is concerned, it is found naturally in the soil, water and vegetables (sprouts, lettuce, leafy veggies, etc.). A beneficial part with this bacterial strain is the ability to fix atmospheric nitrogen in a more usable form for plants. Hence, it is a diazotrophic bacteria. In humans, it can be isolated from the skin, pharynx and gastrointestinal tract. Identified as a common hospital-acquired pathogen, this bacterium is responsible for causing several community-acquired infections.
Diseases caused by Klebsiella
Species belonging to the Klebsiella are ubiquitous and found everywhere. And when they become pathogenic, these bacteria are particularly found in the respiratory, intestinal, and urogenital tract. Diseases caused by Klebsiella include pneumonia (an inflammatory illness of the lungs), urinary tract infections (UTI), ankylosing spondylitis (degenerative inflammatory arthritis), septicemia (whole body inflammation) and soft body infections in humans.
Klebsiella pneumoniae, the name itself suggests that this strain of Klebsiella genus causes pneumonia in humans, and the disease is termed Klebsiella pneumonia. Besides lungs, infections in the intra abdominal parts and urinary tract are also reported. In fact, it is the second most virulent pathogen, next to E. coli, which causes UTI. It normally affects persons with low immune system such as hospital patients, diabetes patients and people with chronic lung disease. Also, people who indulge in excessive alcohol consumption are more prone to K. pneumoniae infections than others.
To be more precise, Klebsiella pneumonia is either hospital-acquired or community-acquired. While it is difficult for K. pneumoniae strain to infect lungs of healthy persons, it produces a highly lethal pneumonia in patients who have been hospitalized, typically after two days of hospitalization. As a matter of fact, this hospital-acquired pneumonia tends to be very serious. It is characterized by a serious, rapid-onset illness, associated with production of bloody sputum (hemoptysis), cell death and destruction of the lungs.
- A notable symptom of Klebsiella pneumonia is cough with sputum secretion.
- The patient may also experience chills, chest pain, high fever, shortness of breath and flu-like symptoms.
- In severe cases, it may cause lung destruction and formation of lung abscesses (pockets of pus).
- Pus may also be present in tissues surrounding the lungs (a condition known as empyema), which can lead to formation of scar tissues.
Diagnosis and Treatment
Diagnosis of Klebsiella pneumonia is done on the basis of patient's symptoms, physical examination with further investigations like chest X-ray, blood test and sputum cultures. If infection is confirmed in the test results, a specific course of antibacterial therapy is recommended. For treatment of this bacterial pneumonia, antibiotics such as aminoglycoside and bactericidal (bacteriua-killing) drugs like cephalosporin are usually prescribed medications. In most instances, repetitive occurrence of the disease is seen, and patients take a longer period to recuperate fully.
The actual treatment for Klebsiella pneumonia depends upon the patient's health condition, medical history and severity of the infection. In conjunction to antibiotic medication, phage therapy may be suggested for this type of bacterial pneumonia. However, a concerning issue with administration of bacteriophages (a type of virus) and antibiotics is the likeliness of bacteria becoming resistant to both. Unlike other mild bacterial infections, this Klebsiella pneumonia is very difficult to treat. Hence, it is always recommended to take precautions to prevent from such infections. With advancement in hospital management and sterilization procedures, the incidence of K. pneumoniae infections is greatly reduced in the last few decades.
Disclaimer: This article is for informative purposes only, and should not be used as a replacement for expert medical advice.