Mycobacterium avium subsp. Paratuberculosis and the expression of selected virulence and pathogenesis genes in...

Area of Science:

• Microbiology
• Molecular Biology
• Food Science

Background:

• Mycobacterium avium subsp. paratuberculosis (MAP) is an important pathogen.
• Understanding MAP's response to environmental stressors is crucial for food safety and control.
• Gene expression under stress conditions (temperature, pH) is key to MAP's survival and virulence.

Purpose of the Study:

• To examine the expression of selected MAP genes related to virulence, adhesion, and stress response.
• To investigate MAP gene expression under conditions relevant to the food industry (refrigeration, pasteurization, stomach pH).
• To compare gene expression profiles across MAP isolates with varying passage histories.

Main Methods:

• Real-time reverse transcription PCR (RT-PCR) was used to quantify gene expression.
• Three distinct MAP isolates with different cultivation passages were analyzed.
• MAP cultures were subjected to temperature stresses (6°C, 65°C) and acidic conditions (pH 2.0).

Main Results:

• Distinct gene expression profiles were observed among the three MAP isolates.
• Under temperature stress, SigE, sigF, and ahpC genes were upregulated, while sigL was downregulated.
• The Mmp gene was downregulated under acidic conditions, and low-passage isolates exhibited some acid resistance.

Conclusions:

• MAP exhibits differential gene expression in response to temperature and pH stress.
• Specific genes (SigE, sigF, ahpC, sigL, Mmp) play roles in MAP's stress response.
• Isolate passage history influences gene expression and acid resistance, with implications for MAP survival in food processing and host environments.