Campylobacter is a leading cause of human gastroenteritis throughout the world. Campylobacter is zoonotic. It can move through live production unnoticed as it does not cause disease in poultry but can be detrimental to human health, especially for the immunocompromised.
Campylobacterosis in Humans
Campylobacter is estimated to cause nearly 9 million foodborne illness cases within the EU and 1.5 million cases in the US every year. It's easy to overlook the prevalence of Campylobacter, as it has similar symptoms as most foodborne pathogens. Out of the estimated 9 million cases of Campylobacteriosis in the EU, only approximately 246,000 are reported annually.
Poultry products are considered a primary source of Campylobacter. Transmission of Campylobacter from chicken is estimated to account for 50-80% of all human Campylobacteriosis cases. Campylobacteriosis can lead to chronic diseases such as Irritable Bowel Syndrome, Arthritis, Guillain-Barré Syndrome, and more within the immunocompromised population. Improper handling of poultry meat is linked to human cases research indicates poultry is responsible for nearly 80% of human cases.
Prevalence of Campylobacter in Poultry
Adequately adapted to hosts such as broiler chickens, Campylobacter possesses several survival mechanisms that permit the colonization and proliferation within the gastrointestinal system and live production. Unfortunately, no clear intervention strategy has emerged. Knowing what we know about Campylobacter's ability to manifest and spread throughout poultry production systems and be further transmitted to humans dictates the need for intervention. However, despite our knowledge of Campylobacter and how it spreads – we still don't completely understand how it enters the production cycle.
Both vertical and horizontal transmission of Campylobacter movement throughout poultry production is documented in the literature. Evidence of Campylobacter contamination of egg surfaces and transmission via infected ovaries supports the arguments behind vertical transmission and the need to protect parent stocks from Campylobacter infection. However, the rapid colonization of flocks is a clear result of horizontal transmission, and the only prerequisite is the introduction of Campylobacter to a flock. Once infected, Campylobacter colonizes the gut and sheds via fecal matter. Once released into the housing environment, it spreads through bird movement, equipment and human traffic.
Campylobacter in Live Production
How does Campylobacter get into chicken? Many experts have debated and tentatively listed fomites for Campylobacter in live production as people, equipment, rodents, water and feed.
Mitigating Campylobacter in poultry production requires the implementation of adequate prevention strategies. Nearly all poultry operations have biosecurity measures to prevent pathogen introduction. However, all pathogens are unique and may require different control strategies. To implement control strategies for every fomite and every pathogen of interest would bear an outrageous cost. Therefore, implementing pathogen control interventions requires thorough investigation.
Questions for evaluation include:
- Which potential fomite poses the most significant threat?
- Where do we have the most control?
- Where would intervention is most impactful?
Seems simple right? Answer the questions, implement the solution. But, to answer each question, we must have a clear understanding of the risk each fomite carries. Can we repeatedly isolate Campylobacter from each vector? How often does each vector meet the flock? Unfortunately, when it comes to Campylobacter, we don't have all the information required to answer those questions.
A big reason for this is the delicate nature of Campylobacter. The Bacteriological Analytical Manual published by the Food and Drug Administration states that everyday environmental stresses such as air exposure, low pH, temperature variation and dry conditions can inhibit recovery. Stressed Campylobacter enters survival mode by changing shape; they become coccoidal and are harder to recover and culture. While well adapted for poultry production and digestive systems, Campylobacter is much like Salmonella when it comes to recovery, it's there, but it can be challenging to isolate.
To determine the risk and justify intervention for Campylobacter fomites, we need to confidently, accurately and consistently collect and analyze samples for the presence of Campylobacter.
Recovering Campylobacter from Feed
Historically feed has been determined a low-risk fomite for Campylobacter, as the low moisture content in feed creates a hostile living environment. However, in recent years researchers have begun to reevaluate feed as a fomite for Campylobacter. The study, Recovery of Campylobacter from Feed Using Different Enrichment Media, evaluated how different enrichment practices can impact the recovery of Campylobacter from feed. This study consisted of five trials, each using feed contaminated with a strain of gentamicin-resistant Campylobacter. Feed was enriched in two different enrichment media in the first three trials, a standard Bolton's Broth versus Bolton's Broth containing antibiotic supplement. Bolton's Broth containing antibiotic supplement demonstrated successful repeated recovery of Campylobacter from feed over a testing period of ten days.
In trials 4 and 5, the number of broths tested increase from two to four. Three of the broths used different combinations of antibiotic supplements. Once again, broths containing antibiotic supplements successfully recovered Campylobacter compared to the Bolton's Broth containing no supplements. These final trials also examined the role of other anaerobic and aerobic bacteria on the recovery of Campylobacter from feed. Bolton's Broth containing supplements demonstrated reduced anaerobic and aerobic bacterial growth and higher enrichment media pH values post-incubation, suggesting that overgrowth of background microflora may mask the presence of Campylobacter by hindering its ability to grow during enrichment. Overall, this study demonstrated that Campylobacter can repeatedly be recovered from contaminated feed and suggests more research on the use of antibiotic supplements during sample enrichment may change our understanding of feed as a fomite for Campylobacter.
To find out more about Campylobacter in poultry and feed as a fomite for Campylobacter, meet with an expert today.