- Helicobacter canis is a Gram-negative, spiral-shaped bacterium categorized within the enterohepatic Helicobacter species (EHS) group.
- Originally identified in dogs and cats, it has since been found in humans and other animals, highlighting its zoonotic potential.
- Although its exact pathogenic role remains uncertain, growing evidence connects H. canis with gastrointestinal infections, hepatobiliary diseases, and systemic illnesses in individuals with weakened immune systems.
- Its presence in domestic animals and humans raises concerns regarding public health, veterinary medicine, and food safety.
- The bacterium’s ability to colonize the intestinal tract, liver, and bloodstream underlines its capacity to cause chronic infections and contribute to inflammatory diseases.
Morphology and Unique Characteristics
- H. canis is a highly motile bacterium characterized by its curved or spiral-shaped structure.
- It is equipped with multiple bipolar flagella, granting it significant motility and enabling its navigation through mucus layers in the gastrointestinal and hepatobiliary systems.
- The bacterium is oxidase-positive and urease-negative, distinguishing it from Helicobacter pylori, which relies on urease for survival in acidic environments.
- Additionally, H. canis thrives under microaerophilic conditions, requiring low oxygen levels for optimal growth.
- Its zoonotic nature is notable, as the bacterium has been observed in both animals and humans, raising concerns about cross-species transmission.
Host Range and Zoonotic Transmission
- First isolated from dogs, H. canis has since been detected in various hosts, including cats, cattle, rodents, and humans.
- In dogs and cats, the bacterium colonizes the intestines and liver, while in humans, it has been identified in individuals suffering from gastrointestinal, hepatic, and systemic infections, particularly those with compromised immune systems.
- Transmission pathways include fecal-oral routes, foodborne exposure, and environmental contact via contaminated surfaces or water.
- Although H. canis is not commonly recognized as a human pathogen, increasing reports of infections highlight its zoonotic potential, especially in scenarios involving close contact with infected animals.
Pathogenesis and Associated Diseases
- While H. canis is often asymptomatic in animals, it has been linked to a range of diseases in both animals and humans.
- In the gastrointestinal tract, it is associated with inflammatory bowel disease (IBD), chronic diarrhea, and mild colonic inflammation.
- In the hepatobiliary system, H. canis has been implicated in chronic hepatitis, cholangitis, biliary fibrosis, and liver abscesses.
- In systemic infections, particularly in immunocompromised individuals, the bacterium has been found in blood cultures, causing sepsis and fever of unknown origin. These findings highlight its significance as an opportunistic pathogen in high-risk patients.
Detection and Treatment
- Due to its specific growth requirements, H. canis detection often relies on advanced molecular techniques such as polymerase chain reaction (PCR).
- Histopathological analysis and blood cultures are also employed to identify its presence.
- Treatment typically involves combination antibiotic therapy, including macrolides, fluoroquinolones, and beta-lactam antibiotics.
- Preventive measures, such as maintaining hygiene, proper handling of animals, and screening for infection, can reduce transmission risk.
