Some chicken meat sold around Nairobi carries bacteria that is resistant to critically important antibiotics, tests by the University of Nairobi have shown.
The high prevalence of multidrug-resistant E coli in Nairobi chicken meat may pose a human health risk from consumption of undercooked meat or unsanitary handling of the contaminated chicken.
E coli lives in the intestines of people and animals but can cause various diseases, including pneumonia, urinary tract infections and diarrhoea when ingested.
Tino Deng, from UoN’s department of Veterinary Pathology and his colleagues said they tested chicken meat from three different sources: sick birds from a veterinary clinic, farm chickens and chickens from Nairobi’s poultry markets.
They took swabs from the anal openings of the carcasses and tested them for E coli, with subsequent testing to evaluate the bacteria’s resistance to eight commonly used antibiotics: ampicillin, tetracycline, co-trimoxazole, streptomycin, nalidixic acid, amoxicillin, gentamicin and chloramphenicol.
The results are published in the Veterinary Medicine International, in an article titled, “Antimicrobial Resistance Profiles of E coli Isolated From Pooled Samples of Sick, Farm and Market Chickens in Nairobi county, Kenya.”
The researchers note that E coli strains were present in about 31.4 per cent of samples tested, with resistance levels highest among chickens brought in for treatment, followed by farm chickens and then market chickens.
The bacteria showed a stark profile of resistance across several antibiotics.
“Antimicrobial resistance results of this study showed that E coli isolates from the screened chickens were resistant, though at varying levels, to some of the commonly used antimicrobials, predictably because they [the drugs] are cheap and, therefore, affordable to the inhabitants of the study area,” Tino and his colleagues said.
“All 54 isolates exhibited varying antimicrobial resistance profiles, with a majority showing high resistance to commonly used drugs like ampicillin (85.22 per cent), tetracycline (66.7 per cent), co-trimoxazole ( 57.4 per cent), and streptomycin ( 40.7 per cent),” he added.
Lower resistance was observed for nalidixic acid ( 24.1 per cent) and chloramphenicol ( 14.8 per cent).
Amoxicillin and gentamicin showed the lowest resistance rates, with susceptibility levels above 96 per cent. This reflects how antibiotic use in intensive farming practices may be contributing to resistance patterns observed in both sick and healthy birds, the researchers said.
Perhaps most concerning is the prevalence of multidrug resistance: more than 81 per cent of the isolates were resistant to multiple antibiotics.
Specifically, 10 isolates were resistant to two antibiotics, 15 to three, eight to four and 10 isolates to as many as five or six different antibiotics.
Ampicillin was the most common antibiotic found in multidrugresistant combinations, followed closely by tetracycline and cotrimoxazole.
The study suggests that the indiscriminate use of antibiotics in livestock—often as growth promoters or preventative measures—has contributed significantly to the drug resistance observed.
This issue is not unique to Kenya, however, with few surveillance measures in place, understanding the full scale of resistance remains difficult.
“The resistance may have developed as a result of high or indiscriminate usage of the antimicrobials in the area; either on the humans or their animals.
“It may also be as a result of
environmental contamination
through human/animal movement
across the area, through faecal
contamination, spitting or other
excrements, or through careless
disposal of medicines.”
