Helicobacter cholecystus

• Helicobacter cholecystus is a Gram-negative, microaerophilic, spiral-shaped bacterium within the Helicobacter genus. 
• It was first isolated from the gallbladders of Syrian hamsters (Mesocricetus auratus) suffering from cholangiofibrosis and centrilobular pancreatitis. 
• This discovery highlighted the association of Helicobacter species with hepatobiliary diseases in non-human hosts and expanded the understanding of Helicobacter diversity.

Morphology and Characteristics 

• H. cholecystus exhibits several defining features typical of the Helicobacter genus. 
• The bacterium is filamentous and spiral-shaped, which facilitates its movement through mucus layers in the gastrointestinal and hepatobiliary systems. 
• It is Gram-negative, characterized by a thin peptidoglycan layer and an outer membrane. 
• As a microaerophilic organism, H. cholecystus thrives in environments with reduced oxygen levels, such as the gallbladder. It is motile, possessing a single polar-sheathed flagellum, which aids in its colonization and persistence within the host.

Isolation and Host Association 

• The initial isolation of H. cholecystus occurred during studies of Syrian hamsters with hepatobiliary diseases. 
• It was recovered from the gallbladders of hamsters exhibiting cholangiofibrosis and centrilobular pancreatitis, suggesting a specific association with these conditions. 
• The bacterium’s presence in hamsters highlights its potential role in hepatobiliary pathology and underscores the importance of studying Helicobacter species in laboratory animals.

Taxonomy and Nomenclature 

• The species name “cholecystus” is derived from the Latin word “cholecystis,” meaning gallbladder, reflecting its association with gallbladder disease. 
• Genetic and phenotypic analyses confirmed its classification as a distinct species within the Helicobacter genus. 
• The type strain of H. cholecystus is designated as ATCC 700242, providing a reference for future studies. 
• Its identification contributes to the expanding taxonomy of Helicobacter species and emphasizes the genus’s adaptability to diverse hosts and organ systems.

Pathogenic Potential and Research Relevance 

• H. cholecystus has been associated with hepatobiliary diseases in Syrian hamsters, including cholangiofibrosis and pancreatitis. 
• Histopathological studies have revealed bile duct hyperplasia, pericholangial fibrosis, and inflammation in infected animals. 
• While its exact pathogenic mechanisms remain unclear, H. cholecystus is thought to play a role in the development of these conditions. 
• Its identification in laboratory animals highlights its relevance in research on Helicobacter-associated diseases and hepatobiliary pathology.

Public Health and Research Implications 

• The discovery of H. cholecystus underscores the importance of studying Helicobacter species in laboratory animals. 
• While there is no evidence to suggest zoonotic transmission or human health implications, monitoring Helicobacter species in research models is essential for understanding their ecological roles and potential risks. 
• Research into H. cholecystus may provide insights into the broader Helicobacter genus and its role in hepatobiliary diseases.