Escherichia albertii

Escherichia albertii 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. albertii is an emerging pathogen that has been associated with gastroenteritis in humans and animals.

History

Escherichia albertii was first described in 2003 by Huys et al. It was initially identified as a distinct species based on its unique biochemical and genetic characteristics, which differentiate it from other members of the Escherichia genus.

Morphology

E. albertii is a Gram-negative bacterium, which means it does not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. It is rod-shaped and typically measures 1-3 micrometers in length. Like other members of the Escherichia genus, E. albertii is facultatively anaerobic, meaning it can grow in both the presence and absence of oxygen.

Genomic Characteristics

The genome of Escherichia albertii is composed of a single circular chromosome. It shares many genetic similarities with Escherichia coli, but also possesses unique genetic markers that distinguish it as a separate species. The genome size is approximately 4.5 to 5.0 million base pairs, and it contains genes that encode for various virulence factors.

Pathogenicity

Escherichia albertii is considered an emerging pathogen. It has been implicated in outbreaks of gastroenteritis in humans. The bacterium is known to produce Shiga toxin, which is a potent cytotoxin that can cause severe intestinal damage. Infections with E. albertii can lead to symptoms such as diarrhea, abdominal pain, and fever.

Virulence Factors

E. albertii possesses several virulence factors that contribute to its pathogenicity:

• Shiga toxin: This toxin inhibits protein synthesis in host cells, leading to cell death and tissue damage.
• Adhesins: These are surface proteins that allow the bacterium to adhere to the intestinal epithelium, facilitating colonization and infection.
• Type III secretion system: This is a needle-like structure used by the bacterium to inject effector proteins into host cells, manipulating host cell functions to the bacterium's advantage.

Epidemiology

Escherichia albertii has been isolated from both human and animal sources. It has been detected in poultry, which is considered a potential reservoir for the bacterium. Human infections have been reported in various countries, indicating a global distribution. The exact prevalence of E. albertii infections is not well understood, partly due to challenges in distinguishing it from other Escherichia species in clinical settings.

Diagnosis

Diagnosing Escherichia albertii infections can be challenging due to its phenotypic similarity to Escherichia coli. Molecular methods, such as polymerase chain reaction (PCR) and sequencing of specific genetic markers, are often required to accurately identify the bacterium. Traditional culture methods may not reliably differentiate E. albertii from other enteric bacteria.

Treatment

The treatment of Escherichia albertii infections typically involves supportive care, such as rehydration and electrolyte replacement, especially in cases of severe diarrhea. The use of antibiotics may be considered in certain cases, but the choice of antibiotic should be guided by antimicrobial susceptibility testing due to potential resistance.

Prevention

Preventive measures for Escherichia albertii infections include proper food handling and hygiene practices to reduce the risk of transmission. Cooking poultry and other meats to appropriate temperatures can help eliminate the bacterium. Public health measures to monitor and control outbreaks are also important in preventing the spread of E. albertii.

Research Directions

Ongoing research is focused on better understanding the epidemiology, pathogenic mechanisms, and genetic diversity of Escherichia albertii. Improved diagnostic methods and surveillance systems are needed to accurately assess the public health impact of this emerging pathogen.

See Also

• Escherichia coli
• Shiga toxin
• Gastroenteritis