A new study explores Nitroxoline, an older antibiotic, as a promising alternative to traditional antibiotics in poultry feed. Its potential role addresses the growing need for antibiotic stewardship and sustainable practices in livestock systems.
Look at older antibiotics
New research from the Ineos Oxford Institute for antimicrobial research (IOI), working with China Agricultural University, suggests that Nitroxoline could offer poultry producers a viable alternative to commonly used antibiotics such as tetracycline.
Nitroxoline, an older antibiotic, historically used to treat urinary tract infections in a handful of countries, demonstrated strong antibacterial performance and favourable growth outcomes in controlled poultry studies.
Potential in poultry
The findings, published in the journal Antibiotics, highlight Nitroxoline’s potent activity in laboratory testing and its efficacy in treating infected chickens. Researchers found that the drug improved body weight, reduced bacterial loads, showed minimal toxicity, and cleared rapidly from tissues – all key characteristics for antibiotics used in livestock environments.
Across global farming systems, antibiotics continue to play a significant role in preventing and treating disease and, in some regions, supporting growth. In 2020, an estimated 99,502 tonnes were used in livestock production worldwide, a figure projected to rise to more than 107,000 tonnes by 2030.
However, increasing concern over antimicrobial resistance has intensified the search for safer, more targeted alternatives. By 2023, 1 in 6 bacterial infections globally was resistant to antibiotics, reinforcing the urgency of developing new strategies within both human and veterinary medicine.
Withdrawing antibiotics from livestock production without presenting alternative tools would have major repercussions for productivity, animal welfare, and food prices.” — Professor Timothy Walsh, director of Biology at IOI and lead author of the study
Seeking agricultural antibiotic alternatives
Researchers on the Nitroxoline study focused on identifying older antibiotics with limited human application but strong potential for agricultural use. Tetracycline, a drug commonly used for human infections but also widely administered in poultry systems, served as the primary comparator throughout the trials.
The team assessed Nitroxoline through a combination of laboratory experiments (in vitro) and controlled animal studies (in vivo). These evaluated antibacterial effectiveness, tolerability, infection control, growth performance, and impacts on gut microbiota.
Balancing productivity and human health
Professor Timothy Walsh, director of Biology at IOI and lead author of the study, said withdrawing antibiotics from livestock production without presenting alternative tools would have major repercussions for productivity, animal welfare, and food prices. He added that Nitroxoline was selected because of its broad antibacterial spectrum, simple structure, low manufacturing cost, and historically low toxicity in human clinical use.
Because Nitroxoline is now rarely used in people – currently prescribed mainly in Germany for urinary tract infections – its use in poultry is less likely to undermine critical treatments in human medicine.
Study shows growth and health gains
In the controlled infection study, 216 broiler chickens were deliberately infected with Salmonella pullorum. Nitroxoline was delivered through feed at 2 dose levels over 10 days. Birds receiving Nitroxoline showed significantly lower bacterial levels in the liver compared with untreated controls, demonstrating strong infection control.
A separate 42-day growth study involving 270 birds found that chickens fed NTX for a 10-day period displayed improved weight gain and feed efficiency. Their performance was comparable to birds receiving a commonly used antibiotic, with no adverse health effects observed.
Reducing reliance on key antibiotics
Researchers concluded that Nitroxoline could represent a realistic alternative to traditional antibiotics in commercial poultry systems. The improvements in bird health, growth, and gut microbiota, combined with minimal toxicity, make Nitroxoline an appealing candidate for future use.
The authors emphasise that further research is required, particularly longer-term field trials, assessments across different bacterial challenges, and regulatory evaluation. Nonetheless, the study provides a strong foundation for considering Nitroxoline as part of integrated poultry health programmes aimed at reducing reliance on medically important antibiotics.
