Gram Research analysis found that nearly all broiler chickens (99.5%) in Hungary carry bacteria resistant to multiple antibiotics, significantly higher than other poultry types. Broiler chickens and turkeys showed 33 to 63 percent more antibiotic-resistant bacteria compared to breeder chickens. Different farm types select for different resistance patterns, suggesting that poultry surveillance programs should track each type separately rather than combining all birds together.
Researchers in Hungary tested nearly 900 bacteria samples from healthy chickens and turkeys to see how many had become resistant to antibiotics. They found that different types of farms (ones that raise chickens for meat versus eggs, for example) had very different levels of antibiotic resistance. Broiler chickens, which are raised specifically for meat, had the highest rates of resistance. This matters because these resistant bacteria can potentially spread to people through the food supply. The study shows that tracking antibiotic resistance needs to look at each type of farm separately, not lump all poultry together.
Key Statistics
A 2026 study of 880 bacteria samples from Hungarian poultry farms found that 99.5% of broiler chicken isolates carried multidrug-resistant bacteria, compared to 87.1% of turkey breeders and 84.3% of broiler turkeys.
According to research reviewed by Gram, broiler chicken isolates showed 63% higher expected numbers of antibiotic-resistant endpoints compared to breeder chicken isolates (95% confidence interval: 1.38 to 1.93).
A 2026 analysis of 880 Escherichia coli samples from five poultry production types in Hungary demonstrated that resistance patterns differed significantly across production categories, with broiler systems showing the highest multidrug resistance burden.
Research from 2022 to 2023 Hungarian poultry farms showed that broiler turkey isolates had 33% higher expected numbers of resistant antibiotic classes compared to breeder chickens (95% confidence interval: 1.20 to 1.47).
The Quick Take
- What they studied: Whether healthy chickens and turkeys on different types of farms carry bacteria that resist antibiotics, and whether resistance patterns differ based on the farm type.
- Who participated: 880 bacteria samples collected from five different poultry groups in Hungary during 2022 and 2023: breeder chickens (98 samples), broiler chickens raised for meat (185 samples), egg-laying hens (127 samples), broiler turkeys for meat (338 samples), and turkey breeders (132 samples).
- Key finding: Nearly all broiler chickens (99.5%) carried bacteria resistant to multiple antibiotics. Broiler chickens and turkeys had significantly more antibiotic-resistant bacteria than breeder chickens. Resistance patterns varied dramatically depending on the type of farm and bird.
- What it means for you: The bacteria in the meat chickens you buy may be more likely to carry antibiotic resistance than bacteria from other poultry sources. This could matter if resistant bacteria reach your food. However, proper cooking kills bacteria, so food safety practices remain important. The findings suggest health officials should monitor different poultry types separately.
The Research Details
Researchers collected bacteria samples from five different types of poultry farms across Hungary. They tested 880 individual bacteria samples to see which antibiotics could kill them and which ones the bacteria could resist. They used standardized laboratory methods to measure resistance, testing each sample against 11 different antibiotics that represent seven different drug categories.
The team then organized the resistance patterns into groups using a statistical method called cluster analysis. This helped them see if certain farms or bird types had similar resistance patterns. They used advanced statistical models to account for the fact that some counties had more samples than others, and they ran sensitivity analyses to check if their main findings held up under different analytical approaches.
This approach allowed them to compare resistance rates between broiler chickens (meat birds), egg-laying hens, breeder birds, and turkeys, and to see whether the source of the sample (like the specific farm or region) affected the results.
Antibiotic resistance is a major public health concern. When bacteria become resistant to antibiotics, the drugs stop working to treat infections in people. By studying healthy farm animals, researchers can detect resistance before it becomes a human health crisis. Different poultry production systems use different practices, housing conditions, and potentially different antibiotic treatments, so they may select for different resistant bacteria. Understanding these differences helps public health officials target surveillance and prevention efforts more effectively.
The study used standardized laboratory methods recognized internationally (CLSI and EUCAST standards) to measure antibiotic resistance, which increases reliability. The sample size of 880 bacteria isolates is substantial. The researchers used appropriate statistical methods for this type of data and ran sensitivity analyses to verify their findings. However, the study was limited to Hungary during one time period, so results may not apply to other countries or years. Some antibiotic classes had limited data, making those results less certain. The study is observational rather than experimental, so it shows associations but cannot prove that farm type causes resistance differences.
What the Results Show
Broiler chickens (meat chickens) had the highest rates of multidrug resistance, with 99.5% of samples showing resistance to multiple antibiotic classes simultaneously. This was followed by turkey breeders at 87.1% and broiler turkeys at 84.3%. Breeder chickens and egg-laying hens had lower rates of multidrug resistance.
When researchers counted how many different antibiotic classes each bacteria sample resisted, broiler chickens and broiler turkeys had significantly higher counts than breeder chickens. Broiler chicken isolates showed 63% more resistant endpoints on average compared to breeder chickens. Broiler turkey isolates showed 33% more resistant endpoints.
The specific patterns of which antibiotics the bacteria resisted varied across the different poultry types. This suggests that different farm systems may be selecting for different types of resistant bacteria. The resistance patterns were also influenced by geographic location, with some counties showing different patterns than others.
The study identified seven distinct clusters of resistance patterns using statistical analysis. Different poultry types clustered differently, meaning each type of farm had its own characteristic resistance signature. Resistance to aminoglycoside antibiotics and folate-pathway antibiotics showed patterns that were more dependent on geographic location and had sparser data, making these findings less certain. The source of the sample (whether it came from the farm environment or directly from the birds) sometimes affected resistance patterns, though this varied by antibiotic class.
Previous research has documented antibiotic resistance in farm poultry, but most studies treated all poultry as a single category. This study’s finding that resistance patterns differ substantially across poultry types supports the idea that surveillance programs need to be more specific. The high rates of multidrug resistance in broiler chickens align with concerns raised in other countries about intensive meat production systems. The study adds to growing evidence that production system type is an important factor in understanding antibiotic resistance in food animals.
The study only included samples from Hungary during 2022 and 2023, so findings may not apply to other countries or time periods. Some antibiotic classes had very few resistant samples, making statistical estimates uncertain for those drugs. The geographic distribution of samples was uneven, with some counties better represented than others. The study is observational, so it cannot prove that farm type causes resistance differences, only that they are associated. The researchers could not determine whether resistance differences were due to antibiotic use practices, housing conditions, feed additives, or other factors. Results should not be generalized beyond the Hungarian poultry industry without additional research.
The Bottom Line
High confidence: Consumers should continue following food safety practices including proper cooking temperatures, which kill bacteria regardless of antibiotic resistance. Medium confidence: Public health agencies should implement antibiotic resistance surveillance programs that track different poultry types separately rather than combining all poultry data. Medium confidence: The poultry industry should evaluate whether current practices in broiler chicken production are contributing to high resistance rates and consider modifications. Low to medium confidence: Consumers concerned about antibiotic resistance may consider purchasing poultry from production systems with lower documented resistance rates, though more research is needed on whether this translates to lower risk.
Public health officials and food safety regulators should care most about these findings, as they inform surveillance strategies. Poultry producers should care because the data suggests their production system type affects resistance patterns. Consumers should be aware but should not panic, as proper food handling eliminates the risk. Healthcare providers should note that resistance patterns vary geographically and by poultry source. Researchers studying antibiotic resistance should use these findings to design more targeted surveillance programs.
This research provides a snapshot of resistance patterns during 2022 and 2023. Changes in resistance rates would likely take months to years to develop, depending on antibiotic use practices. If the poultry industry made changes to reduce antibiotic use or improve conditions, resistance rates might decrease over 1 to 3 years. Consumers would not see personal health effects from this research immediately, but it informs long-term public health strategy.
Frequently Asked Questions
Are antibiotic-resistant bacteria in chicken dangerous to eat?
Proper cooking kills bacteria regardless of antibiotic resistance, so cooked chicken is safe. The concern is if resistant bacteria spread to people through undercooked food or cross-contamination. Following food safety practices like cooking to proper temperatures and preventing cross-contamination eliminates this risk.
Which type of poultry has the most antibiotic-resistant bacteria?
Broiler chickens raised for meat showed the highest rates of multidrug-resistant bacteria at 99.5%, followed by turkey breeders at 87.1% and broiler turkeys at 84.3%. Breeder chickens and egg-laying hens had lower resistance rates.
Why do different poultry farms have different levels of antibiotic resistance?
Different production systems use different housing conditions, feed practices, and potentially different antibiotic treatments. These differences create different selection pressures that favor certain resistant bacteria. Broiler systems, which raise many birds in close quarters, may select more strongly for resistance.
Should I be worried about buying chicken from the grocery store?
No need to worry if you follow food safety practices. Cook chicken to 165 degrees Fahrenheit, avoid cross-contamination with other foods, and wash your hands and surfaces. These practices eliminate bacterial risk regardless of antibiotic resistance status.
How does antibiotic resistance in farm animals affect human health?
Resistant bacteria from animals can enter the food chain and potentially spread to people. If someone develops an infection with these resistant bacteria, antibiotics may not work to treat it. This is why tracking resistance in farm animals helps public health officials prepare and prevent problems.
Want to Apply This Research?
- Users could track their poultry purchases by type (broiler chicken, turkey, eggs, etc.) and source (conventional farm, specific producer, etc.) to correlate with any gastrointestinal symptoms or infections. This personal data could help identify patterns over time.
- Users could set reminders to follow proper food safety practices (cooking temperatures, cross-contamination prevention) when preparing poultry. The app could provide specific guidance based on the poultry type purchased, since different types carry different resistance profiles.
- Long-term, users could track any antibiotic-resistant infections they develop and correlate them with their poultry consumption patterns and sources. The app could aggregate anonymized data to show users how their practices compare to population averages and provide personalized recommendations based on their local poultry sourcing.
This research describes antibiotic resistance patterns in farm poultry and does not provide medical advice. If you develop a bacterial infection, consult a healthcare provider for diagnosis and treatment. Proper food handling and cooking eliminate bacterial risk regardless of antibiotic resistance status. This study was conducted in Hungary and may not apply to poultry from other countries or regions. The findings are observational and cannot prove that farm type causes resistance differences, only that associations exist.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.