Surreal illustration of sheep and goats facing a distorted virus, symbolizing the challenge of contagious agalactia.

Contagious Agalactia: How a New Mycoplasma Strain Could Impact Livestock

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Soraya Malik in Health & Wellness September 2025 • 4 min read.

"Discover how a novel Mycoplasma agalactiae strain with a unique P30 protein pattern is challenging traditional prevention strategies for contagious agalactia in sheep and goats."


Contagious agalactia (CA) poses a persistent threat to dairy sheep and goat farms, causing significant economic losses due to reduced milk production, arthritis, and keratoconjunctivitis. For decades, farmers have relied on inactivated vaccines to protect their herds, but emerging evidence suggests that these traditional strategies may be losing their effectiveness.

A groundbreaking study has identified a novel strain of Mycoplasma agalactiae, the primary culprit behind CA, with a significantly altered P30 protein pattern. The P30 protein is a key component targeted by the immune system, and changes to its structure could impact how well existing vaccines work.

This discovery has major implications for livestock health and disease management, potentially requiring a re-evaluation of current vaccination protocols and the development of new, more targeted interventions. Understanding this new strain and its unique characteristics is crucial for safeguarding the future of dairy farming.

What Makes This New Mycoplasma Strain Different?

Surreal illustration of sheep and goats facing a distorted virus, symbolizing the challenge of contagious agalactia.

The key difference lies in the P30 protein, a specific and stable lipoprotein found in Mycoplasma agalactiae. Researchers analyzed the complete coding sequence of the P30 gene in three Iranian vaccine strains and ten recent field isolates, using bioinformatics tools to compare their structures. The results revealed a novel protein pattern, characterized by a distinct sequence (K106VLKTKEIRLSQERKLS122) in the vaccine strains, which was not found in the field isolates or other sequences available in GenBank.

This major change involves 17 amino acid substitutions in the P30 protein, potentially altering its shape and function. Such alterations can have significant implications for the immune response, as the altered protein may no longer be recognized as effectively by antibodies produced in response to existing vaccines.

  • Altered Immune Response: The altered P30 protein might not trigger the same robust immune response as the original protein, reducing the vaccine's effectiveness.
  • Evasion of Immune Defenses: The changes could allow the new strain to evade the host's immune defenses, leading to chronic infections.
  • Impact on Diagnostic Tests: Current diagnostic tests that rely on recognizing the P30 protein might produce inaccurate results with the new strain.
The study suggests that the major change in the P30 protein pattern may have occurred due to mutation during the adaptation process in PPLO (Pleuropneumonia-Like Organisms) broth media, a common laboratory environment for culturing mycoplasmas. This highlights the potential for changes to occur during vaccine production and the importance of monitoring these changes to ensure vaccine efficacy.

What Does This Mean for the Future of CA Prevention?

The discovery of this novel Mycoplasma agalactiae strain underscores the need for ongoing surveillance and adaptation of prevention strategies. Further research is crucial to fully understand the impact of the altered P30 protein on vaccine efficacy and to develop new vaccines that can effectively target this emerging strain. By staying ahead of these changes, we can better protect livestock and ensure the sustainability of dairy farming.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

1

What is contagious agalactia and what are the major implications of this disease?

Contagious agalactia (CA) is a significant threat to dairy sheep and goat farms. This disease leads to substantial economic losses due to reduced milk production, arthritis, and keratoconjunctivitis. For years, farmers have depended on inactivated vaccines. A new strain of *Mycoplasma agalactiae* is causing concern as existing vaccines may not be as effective. This discovery could impact how we manage and prevent CA, potentially requiring new vaccination strategies and interventions to safeguard dairy farming.

2

How does the new *Mycoplasma agalactiae* strain differ from the strains targeted by current vaccines?

The key difference lies in the P30 protein, a critical lipoprotein found in *Mycoplasma agalactiae*. The recent study found a novel strain with an altered P30 protein pattern. Specifically, the distinct sequence (K106VLKTKEIRLSQERKLS122) found in the vaccine strains was absent in the field isolates. This change involves 17 amino acid substitutions in the P30 protein, potentially changing its shape and function. These alterations can hinder the immune response, and existing vaccines may not be as effective in providing protection.

3

Why is the change in the P30 protein pattern significant for livestock health?

The changes in the P30 protein have profound implications for livestock health. The altered P30 protein might not trigger the same immune response as the original protein, reducing the vaccine's effectiveness. Also, it might allow the new strain to evade immune defenses, potentially leading to chronic infections. Furthermore, it could impact the accuracy of current diagnostic tests that rely on recognizing the P30 protein, leading to incorrect results, and making it harder to detect the disease early.

4

What is the role of the P30 protein in relation to *Mycoplasma agalactiae* and vaccines?

The P30 protein is a key component of *Mycoplasma agalactiae* and is targeted by the immune system. Vaccines typically use the P30 protein to trigger an immune response. The body then produces antibodies that recognize and neutralize the bacteria. However, changes to the P30 protein's structure, like those observed in the new strain, can hinder this process. The altered protein may not be recognized by the antibodies produced by existing vaccines, reducing their protective effect. This highlights the importance of understanding the P30 protein and its role in vaccine efficacy.

5

How can farmers adapt to the emergence of this new *Mycoplasma agalactiae* strain and what is the future of CA prevention?

The emergence of the novel *Mycoplasma agalactiae* strain necessitates ongoing surveillance and adaptation of prevention strategies. Farmers should stay informed about the latest research and developments in CA prevention. It is essential to develop new vaccines that target the emerging strain effectively. Regular monitoring and assessment of vaccine efficacy are crucial. Future CA prevention requires staying ahead of these changes through continuous monitoring, research, and the development of advanced vaccines to better protect livestock and ensure the sustainability of dairy farming.

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