Enteroaggregative Escherichia coli

Pathogenic type of Escherichia coli''

Enteroaggregative E. coli strain EAEC 042 aggregates during infection of Hep-2 cells.

Enteroaggregative Escherichia coli (EAEC or EAggEC) is a distinct pathotype of the bacterium Escherichia coli (E. coli) that is associated with both acute and chronic diarrhea in individuals from both the developed and developing world. EAEC is recognized for its characteristic adherence pattern and the damage it causes to the intestinal mucosa.

Characteristics

EAEC is defined by its unique stacked-brick pattern of adhesion to HEp-2 cells, which are derived from a human laryngeal epithelial carcinoma cell line. This pattern is observed in vitro and is used as a diagnostic criterion for identifying this pathotype.

Pathogenesis

The disease process of EAEC involves:

• Adherence to the intestinal mucosa using aggregative fimbriae.
• Formation of a biofilm that enhances colonization and protects the bacteria from the host immune system.
• Production of enterotoxins and cytotoxins that disrupt the intestinal epithelium.
• Induction of an inflammatory response, leading to mucosal damage and diarrhea.

Clinical Significance

EAEC has been implicated in a wide range of diarrheal illnesses, including:

• Persistent diarrhea in children
• Traveler’s diarrhea
• Diarrhea in immunocompromised individuals, such as patients with HIV/AIDS

It is also a known contributor to malnutrition in young children due to chronic gastrointestinal inflammation and nutrient loss.

Diagnosis

Diagnosis of EAEC may involve:

• Stool culture followed by adherence assays using HEp-2 or HeLa cells.
• Molecular methods such as polymerase chain reaction (PCR) to detect EAEC-specific genes (e.g., aggR, aaiC).

Treatment

Management generally includes:

• Oral rehydration therapy to prevent dehydration.
• In some cases, antibiotics such as ciprofloxacin or rifaximin may be prescribed, particularly in severe or persistent cases, although antibiotic resistance is an emerging concern.

See also

• Escherichia coli
• Enteropathogenic Escherichia coli
• Enterotoxigenic Escherichia coli
• Diarrhea
• Bacterial pathogenesis