Escherichia hermannii

Escherichia hermannii is a species of bacteria within the genus Escherichia. It is a member of the family Enterobacteriaceae, which includes several other notable species such as Escherichia coli. E. hermannii was first described in 1982 by Brenner et al. and is named in honor of the microbiologist George Hermann.

Morphology and Physiology

Escherichia hermannii is a Gram-negative bacterium, characterized by its rod-shaped morphology. Like other members of the genus Escherichia, it is a facultative anaerobe, meaning it can grow in both the presence and absence of oxygen. The bacterium is motile, possessing peritrichous flagella that allow it to move.

Habitat and Ecology

E. hermannii is commonly found in the environment, including water, soil, and food sources. It has also been isolated from clinical specimens, although it is not typically associated with human disease. The bacterium can survive in a variety of conditions, which contributes to its widespread presence in nature.

Clinical Significance

While Escherichia hermannii is not a major human pathogen, it has been isolated from clinical samples, including urine, wounds, and blood. Its role in disease is not well understood, and it is generally considered to be of low virulence. However, it may act as an opportunistic pathogen in immunocompromised individuals.

Biochemical Characteristics

E. hermannii can be distinguished from other Escherichia species by its unique biochemical profile. It is positive for catalase and negative for oxidase. The bacterium can ferment glucose, producing acid and gas, but does not ferment lactose as rapidly as E. coli. It is also capable of utilizing a variety of other carbohydrates as energy sources.

Genomic Features

The genome of Escherichia hermannii has been sequenced, revealing insights into its genetic makeup and potential functions. The genome contains genes responsible for antibiotic resistance, metabolism, and virulence factors, although the latter are not as prominent as in more pathogenic species like E. coli.

Laboratory Identification

In the laboratory, E. hermannii can be identified using a combination of biochemical tests, molecular techniques, and culture characteristics. It grows well on standard media such as MacConkey agar, where it forms pale colonies due to its slower lactose fermentation.

Public Health and Safety

Due to its low pathogenicity, Escherichia hermannii is not considered a significant public health threat. However, its presence in clinical settings warrants attention, particularly in cases involving immunocompromised patients. Standard infection control measures are sufficient to manage any potential risks associated with this bacterium.

Research and Applications

Research on E. hermannii is limited compared to other Escherichia species, but it remains of interest due to its environmental presence and potential as a model organism for studying bacterial ecology and evolution. Its ability to survive in diverse environments makes it a candidate for studies on bacterial adaptation and resilience.

See Also

• Escherichia coli
• Enterobacteriaceae
• Gram-negative bacteria

External Links

• NCBI Taxonomy Browser: Escherichia hermannii