Hymenolepis microstoma: histopathological changes in mice maintained at different environmental temperatures

Area of Science:

• Veterinary Pathology
• Parasitology
• Environmental Physiology

Background:

• The Hymenolepis microstoma parasite infects the liver and bile ducts of rodents.
• Environmental temperature can influence host physiology and immune responses.
• Understanding the interplay between parasitic infection and host temperature is crucial for disease management.

Purpose of the Study:

• To investigate the impact of different ambient temperatures on the liver histology of mice infected with Hymenolepis microstoma.
• To determine how temperature affects the host's inflammatory and pathological responses to infection.

Main Methods:

• Uninfected and Hymenolepis microstoma-infected mice were housed at three different temperatures: 5 C, 21 C, and 35 C.
• Liver tissues were collected and examined using histological analysis.
• Histopathological changes, including inflammation, necrosis, and bile duct alterations, were assessed.

Main Results:

• Hepatocytes showed glycogen depletion at 35 C in uninfected mice.
• All infected mice exhibited liver inflammatory changes, with less severe histopathology at 21 C compared to 5 C and 35 C.
• Infected mice at extreme temperatures (5 C and 35 C) developed necrotic lesions; livers at 35 C also showed foreign body giant cells.
• Bile duct walls uniformly thickened in all infected mice due to fibrosis and inflammatory cell infiltration.

Conclusions:

• Ambient temperature significantly modulates the severity of liver pathology in Hymenolepis microstoma-infected mice.
• Moderate temperatures (21 C) appear to mitigate the host's inflammatory response to infection.
• Extreme temperatures exacerbate liver damage, highlighting the importance of environmental conditions in parasitic disease outcomes.