What is the Difference Between Klebsiella and Pseudomonas

The main difference between Klebsiella and Pseudomonas is that Klebsiella belongs to the family Enterobacteriaceae, whereas Pseudomonas belongs to the family Pseudomonadaceae.

Klebsiella and Pseudomonas are two types of Gram-negative bacteria that occur in nature. Additionally, both are opportunistic human pathogens.

Key Areas Covered

1. What are Klebsiella
     – Definition, Features, Importance
2. What are Pseudomonas
     – Definition, Features, Importance
3. Similarities Between Klebsiella and Pseudomonas
     – Outline of Common Features
4. Difference Between Klebsiella and Pseudomonas
     – Comparison of Key Differences

Key Terms

Klebsiella, Pseudomonas

What is Klebsiella

Klebsiella is a Gram-negative, rod-shaped bacterium that belongs to the family Enterobacteriaceae. It contains a prominent polysaccharide-based capsule. Moreover, the species is non-motile. Generally, Klebsiella species occur in nature, in soil, water, insects, plants, and animals, including humans. This bacterium develops biochemical adaptations as well as specific niche adaptations. Klebsiella occurs in the nose, mouth, and intestine as a part of human and animal normal flora. When compared to the other species of the family Enterobacteriaceae, Klebsiella is shorter and thicker in shape.

Figure 1: Klebsiella

Furthermore, Klebsiella occurs singly, in pairs, or in chains linked end to end. It can also grow in ordinary lab conditions and does not have special growth requirements as other members of the family. In addition, Klebsiella species is aerobic and mostly facultatively anaerobic. Generally, 35° to 37 °C is the ideal growth temperature for Klebsiella. Meanwhile, the optimal pH level is about 7.2. Klebsiella contains two types of antigens on the surface of the cell. They include O antigen and K antigen. Usually, both antigens contribute to the pathogenicity of the bacterium.      

What is Pseudomonas

Pseudomonas is a Gram-negative genus bacterium belonging to the family Pseudomonadaceae. Generally, it shows metabolic diversity that helps the bacterium colonize a wide range of niches. It occurs in water and plant seeds such as dicots. Pseudomonas is a rod-shaped bacterium that contains polar flagella. Moreover, flagella allow the mobility of the bacterium. Pseudomonas is an aerobic bacterium that is non-spore-forming. In addition, the bacterium is both catalase-positive and oxidase-positive.

Figure 2: Pseudomonas

Moreover, Pseudomonas forms biofilms, and the production of exopolysaccharides is associated with the formation of the biofilms. These biofilms are difficult to remove from food separation surfaces. In addition, Pseudomonas is a strict aerobe. Usually, the bacterium produces a fruity odor. Pseudomonas species is naturally resistant to penicillin. The majority of beta-lactam antibiotics do not allow the growth of Pseudomonas.

Similarities Between Klebsiella and Pseudomonas

• Klebsiella and Pseudomonas are two types of Gram-negative bacteria.
• They naturally occur in the environment.
• Both serve as opportunistic pathogens in humans.
• Both are rod-shaped bacteria. They are aerobic.
• They are non-spore-forming bacteria.

Difference Between Klebsiella and Pseudomonas

Definition

Klebsiella refers to non-spore-forming, non-motile, facultatively anaerobic, and capsulated bacteria, while Pseudomonas refers to the bacterium that occurs in soil and detritus, pathogenic in plants and animals.

Family

Klebsiella belongs to the family Enterobacteriaceae, while Pseudomonas belongs to the family Pseudomonadaceae.

Motility

Klebsiella is motile, but Pseudomonas is non-motile.

Oxidase Activity

Klebsiella is oxidase-negative, while Pseudomonas is oxidase-positive.

Occurrence

Klebsiella occurs in human and animal normal flora in the nose, mouth, and small intestine, while Pseudomonas occurs in water and plant seeds.

Type of Specificity

Klebsiella shows biochemical adaptations and adaptations for specific niches, but Pseudomonas shows metabolic diversity.

Conclusion                                                       

In brief, Klebsiella and Pseudomonas are two types of Gram-negative bacteria that naturally occur in nature. Both are opportunistic pathogens. In addition, they are non-spore-forming aerobic bacteria. Generally, Klebsiella belongs to the family Enterobacteriaceae. It is a motile bacterium that is oxidase-negative. Klebsiella occurs in the normal flora of humans and animals. Under normal conditions, it occurs in the nose, mouth, and small intestine. In comparison, Pseudomonas occurs in soil and detritus and is pathogenic in animals and plants. It belongs to the family Pseudomonadaceae. It is also a non-motile bacterium that is oxidase-positive. Therefore, the main difference between Klebsiella and Pseudomonas is their classification.

References:                

1. Iglewski BH. Pseudomonas. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 27.
2. S. Department of Health and Human Services. (n.d.). Klebsiella infection – about the disease. Genetic and Rare Diseases Information Center. Retrieved February 13, 2023.

Image Courtesy:

1. “Klebsiella-pneumoniae” By Janice Carr – Own work (Public Domain) via Commons Wikimedia
2. “Pseudomonas aeruginosa 01” By CDC – Own Work (Public Domain) via Commons Wikimedia