On-site slaughter and dressing in retail chicken outlets: Escherichia coli contamination and antimicrobial resistance on food-contact surfaces in Dhaka Division, Bangladesh
This study reveals that 50% of food-contact surfaces in retail chicken outlets across Dhaka Division, Bangladesh, are contaminated with multidrug-resistant *Escherichia coli*, predominantly showing high resistance to ampicillin, trimethoprim, and azithromycin, with the presence of *sul3* and *blaOXA-1* genes indicating significant antimicrobial selective pressure and widespread hygiene risks.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
In the bustling markets of Bangladesh, the journey of a chicken from farm to fork involves a critical, often overlooked moment: the on-site slaughter. Unlike in many industrialized nations where birds are processed in large, regulated factories before reaching the store, here the work of dressing the bird—removing feathers, organs, and skin—happens right at the retail counter. This practice means that knives, cutting tables, and mechanical dressing machines are used repeatedly, often with little time for cleaning between birds. These surfaces become the final checkpoint where bacteria can hitch a ride onto the meat that families will take home to cook. The concern is not just about the presence of bacteria, but specifically about Escherichia coli, a common gut bacterium that can turn dangerous when it becomes resistant to the medicines doctors use to treat infections. When bacteria survive exposure to antibiotics, they become "superbugs," making common illnesses harder to cure. This resistance is fueled by the widespread use of antibiotics in farming, which trains these bacteria to survive, and then spreads them through the food chain.
A team of researchers from several universities and institutes in Bangladesh set out to understand exactly how much of a problem this was in the retail chicken shops of the Dhaka Division. They focused on the tools of the trade: the knives used to cut, the tables where the birds are prepared, and the machines that help dress the carcasses. Between July and October 2025, the scientists visited six different outlets in three nearby towns. They did not look at the birds themselves, but rather at the surfaces that touched them. Using sterile swabs, they gently wiped about the size of a standard sheet of paper from each surface, collecting any microscopic life that had settled there. In total, they gathered 180 samples, a mix of swabs from knives, tables, and machines, to see what was hiding on the equipment.
The results revealed a widespread presence of E. coli. Half of all the surfaces they tested were contaminated with the bacteria. The contamination was surprisingly even across the different tools. The knives carried the highest rate, with more than half of them testing positive, followed closely by the cutting tables and the dressing machines. This finding is significant because it shows that the risk is not limited to just one dirty tool; the entire workstation is a reservoir for these bacteria. The researchers found that the level of contamination did not vary drastically between the different towns they visited, suggesting that this is a common issue across the region rather than a problem isolated to a single shop.
What made the situation particularly concerning was the nature of the bacteria found. The researchers tested the E. coli against twelve different types of antibiotics, which represent the main classes of drugs used to fight infections. The bacteria showed a frightening ability to resist these medicines. They were almost universally resistant to ampicillin and trimethoprim, with resistance rates reaching 96 percent. They were also highly resistant to azithromycin, nalidixic acid, and tetracycline. In fact, the vast majority of the bacteria samples were resistant to multiple classes of drugs at once. Only one antibiotic, meropenem, remained effective against most of the bacteria, keeping them at bay. This pattern indicates that the bacteria have been exposed to a heavy mix of antibiotics in their environment, likely from the farms where the chickens were raised, and have adapted to survive.
To understand the genetic basis of this resistance, the team looked for specific genes known to carry instructions for drug resistance. They found genes associated with resistance to sulfonamides and beta-lactams, which are common types of antibiotics. However, a gap appeared between what they found in the genes and what they saw in the lab tests. While the bacteria were resistant to many drugs, the specific genes they looked for could not explain all of that resistance. This suggests that the bacteria are carrying other, untested genetic instructions that allow them to survive. The study also calculated a score to measure how many different drugs each bacteria sample could resist. Most of the samples scored high, indicating they came from an environment where antibiotics are used frequently and heavily.
The study concludes that the surfaces in these retail chicken outlets are active reservoirs for drug-resistant bacteria. Because the bacteria are found on knives, tables, and machines in nearly equal measure, cleaning just one item is not enough to stop the spread. The contamination is distributed across the entire dressing station. This means that even if a worker cleans a knife, the bacteria can still move from the table to the meat, or from the machine to the handler. The researchers emphasize that this is a public health risk, as these resistant bacteria can easily jump from the food to the people handling it. While the study did not test the meat itself, the presence of these bacteria on the tools used to prepare the meat suggests that the final product is likely contaminated. The findings highlight a critical need for better hygiene practices at the point of sale and more careful use of antibiotics in poultry farming to protect the health of the community.
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