A groundbreaking discovery in veterinary science reveals an emerging pathogen in Polish swine populations
Imagine a pig farmer who steps into their barn to find growing pigs, once healthy, now stricken with severe mucohaemorrhagic diarrhea. The illness, known as swine dysentery, doesn't just threaten the well-being of the animals—it carries significant economic consequences for the farming operation.
For decades, veterinarians and scientists attributed this disease to a specific bacterium, Brachyspira hyodysenteriae. But in recent years, the story has grown more complex with the discovery of new pathogenic species. Today, that story takes an intriguing new turn with a groundbreaking discovery on Polish pig farms.
First official detection of B. hampsonii in Poland
Advanced diagnostics reveal evolving pathogen landscape
Highlights pathogen spread across continents
Swine dysentery is a serious condition characterized by mucohaemorrhagic colitis that primarily affects grower-finisher pigs. Beyond animal welfare concerns, the disease inflicts substantial economic losses on producers due to decreased weight gain, poor feed conversion, and treatment costs 1 .
Until the early 2000s, the disease was believed to have a single primary bacterial cause. However, scientific advances have revealed a more complicated picture with three strongly beta-hemolytic Brachyspira species now known to cause swine dysentery 5 8 .
The classic cause of swine dysentery, recognized for decades and found in most major swine-producing regions worldwide.
Initially detected in pigs and water birds in Scandinavia and later in other European countries, including Poland 8 .
First identified in North America around 2007 and provisionally named after Dr. Gerald Hampson.
| Species | Discovery Timeline | Geographical Distribution | Key Biochemical Feature |
|---|---|---|---|
| B. hyodysenteriae | Known for decades | Worldwide, most swine-producing regions | Typically indole-positive |
| B. suanatina | Identified more recently | Scandinavia, Germany, UK, Poland | Not specified in available literature |
| B. hampsonii | First identified ~2007 | North America, Belgium, Germany, Poland | Typically indole-negative 1 |
In March 2023, Polish researchers undertook a study to investigate the presence of Brachyspira species on the country's pig farms. The resulting paper, "First molecular detection of Brachyspira hampsonii on pig farms in Poland," published in 2024, provides a fascinating case study in modern veterinary pathogen surveillance 5 .
The study was conducted on nine different high-performing Polish finisher farms. From each farm, researchers collected a fresh pooled faecal sample representing 40 diarrheic finisher pigs with weights ranging between 60 and 110 kg 5 .
In the laboratory, genetic material (nucleic acid) was extracted from each of the pooled fecal samples. This process isolates the DNA that contains the genetic blueprint of any microorganisms present.
The extracted DNA was then analyzed using a specialized molecular technique called multiplex polymerase chain reaction (PCR). This in-house developed PCR method was specifically designed to both confirm the presence of bacteria from the Brachyspira genus and to differentiate between the various Brachyspira species in a single test 5 9 .
The PCR results were interpreted based on the presence or absence of specific DNA fragments that serve as signatures for the different Brachyspira species.
The findings from the experiment were clear and significant:
| Total Samples Analyzed | B. hampsonii Detections | Other Non-pathogenic/Questionably Pathogenic Brachyspira Detections |
|---|---|---|
| 9 | 2 | 6 |
Out of the nine sample populations examined, the genetic material of B. hampsonii was definitively identified in two 5 . This may seem like a small number, but its importance is substantial.
of tested farms positive for B. hampsonii
The detection of elusive pathogens like B. hampsonii relies heavily on specialized molecular reagents and techniques. The following table outlines the essential components of the molecular detective's toolkit, as used in this field of research.
| Reagent/Method | Function in Research | Application in B. hampsonii Detection |
|---|---|---|
| Multiplex PCR | A molecular technique that uses multiple primer sets to amplify several DNA targets simultaneously in a single reaction 3 . | Used to simultaneously detect the Brachyspira genus and differentiate between B. hyodysenteriae, B. suanatina, and B. hampsonii in a single test 5 9 . |
| Primers | Short, single-stranded DNA sequences that are designed to bind to specific complementary DNA target sequences. | Target species-specific genes (e.g., sections of the nox gene) to initiate amplification, creating millions of copies for detection 1 . |
| DNA Polymerase | A heat-stable enzyme that synthesizes new DNA strands by adding nucleotides to the primers. | Essential for amplifying the target DNA regions during the PCR thermal cycling process. |
| Nucleic Acid Extraction Kits | Commercial kits containing reagents to efficiently isolate and purify DNA from complex sample matrices like feces. | Used to obtain high-quality, inhibitor-free DNA from pig fecal samples for reliable downstream PCR analysis 5 . |
| Gel Electrophoresis Reagents | Agarose gels and DNA staining dyes that allow visualization of amplified PCR products based on their size. | Likely used to confirm the presence and size of the amplified DNA fragments, verifying the identity of the Brachyspira species. |
PCR Amplification Process Visualization
Multiplex PCR allows simultaneous detection of multiple pathogens in a single reaction, saving time and resources while providing comprehensive diagnostic information.
Fecal samples from diarrheic pigs
Isolation of genetic material
Amplification of pathogen-specific genes
Identification based on DNA fragment size
The identification of B. hampsonii in Poland is more than an isolated laboratory result—it has real-world implications for veterinary practice, farm management, and disease tracking.
Since swine dysentery caused by B. hyodysenteriae, B. suanatina, or B. hampsonii is clinically identical, laboratory testing is the only way to identify the specific causative agent.
Knowing which pathogen is present is essential for implementing appropriate control measures and antibiotic treatment protocols, especially since B. hampsonii has been reported to show a generally favorable antibiogram against common antimicrobials like tiamulin and valnemulin 1 .
The research underscores that relying solely on traditional culture-based methods or outdated diagnostic panels can lead to misdiagnosis.
The detection of B. hampsonii in Poland adds another piece to the puzzle of how this pathogen is spreading across continents.
Its previous findings in migratory water birds in both Europe and North America suggest these birds may serve as potential reservoirs and vectors, facilitating the long-distance spread of the bacterium 1 .
Global Distribution Map of B. hampsonii
The first molecular detection of Brachyspira hampsonii on Polish pig farms is a powerful example of how modern science is illuminating the hidden world of animal pathogens.
What once might have been simply diagnosed as "standard" swine dysentery can now be precisely identified, thanks to sophisticated molecular tools like multiplex PCR.
This discovery reinforces that infectious agents do not respect national borders. The continued global movement means that vigilance and advanced surveillance are more critical than ever.
For farmers, veterinarians, and the swine industry, this finding serves as both a warning and a guide: a warning that the pathogen landscape is evolving, and a guide pointing toward the molecular tools needed to navigate it.
As research continues, each new discovery like this one helps build a more resilient defense system for animal health and global food security.