“Superbugs” present in chicken, turkey, beef and pork
By EUROPEAN SOCIETY OF CLINICAL MICROBIOLOGY AND INFECTIOUS DISEASES
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| A Spanish study found 40% of supermarket meat samples contained multidrug-resistant E. coli strains, highlighting the need for regular assessments of antibiotic-resistant bacteria in meat products and emphasizing farm-to-fork interventions and proper food handling practices to reduce risks. |
Multidrug-resistant E. coli were found in 40% of supermarket meat samples tested in a Spanish study. E. coli strains capable of causing severe infections in people were also highly prevalent, this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID 2023, Copenhagen, April 15-18) will hear.
Antibiotic resistance is reaching dangerously
high levels around the world. Drug-resistant infections kill an estimated
700,000 people a year globally and, with the figure projected to rise to 10
million by 2050 if no action is taken, the World Health Organization (WHO)
classes antibiotic resistance as one of the greatest public health threats
facing humanity.
Multidrug-resistant bacteria can spread from
animals to humans through the food chain but, due to commercial sensitivities,
data on levels of antibiotic-resistant bugs in food is not made widely available.
To find out more, Dr Azucena Mora Gutiérrez and Dr Vanesa García Menéndez, of the University of Santiago de Compostela-Lugo, Lugo, Spain, together with colleagues from other research centres, designed a series of experiments to assess the levels of multidrug-resistant and extraintestinal pathogenic Enterobacteriaceae (Klebsiella pneumoniae, E. coli and other bacteria that can cause multidrug-resistant infections such as sepsis or urinary tract infections) in meat on sale in Spanish supermarkets.
They analysed 100 meat products (25 each of
chicken, turkey, beef and pork) chosen at random from supermarkets in Oviedo
during 2020.
The majority (73%) of the meat products
contained levels of E. coli that
were within food safety limits.
Despite this, almost half (49%) contained
multidrug-resistant and/or potentially pathogenic E. coli. From those, 82 E. coli isolates were recovered and characterised.
In addition, 12 K. pneumoniae isolates
were recovered from 10 of the 100 meat products (7 chicken, 2 turkey and 1
pork).
Forty of the 100 meat products contained
multidrug-resistant E. coli (56 of the
82 E. coli characterised). These included E. coli that produced
extended-spectrum beta-lactamases (ESBLs), enzymes that confer
resistance to most beta-lactam antibiotics, including penicillins,
cephalosporins and the monobactam aztreonam.
The percentage of positive samples for the
carriage of ESBL-producing E. coli per
meat type was: 68% turkey, 56% chicken, 16% beef and 12% pork. This higher
presence of ESBL-producing E. coli strains
in poultry compared to other types of meat is likely due to differences in
production and slaughter.
Twenty-seven per cent of the meat products
contained potentially pathogenic extraintestinal E. coli (ExPEC). ExPEC possess genes that
allow them to cause disease outside the gastrointestinal tract. ExPEC causes
the vast majority of urinary tract infections (UTIs), is a leading cause of
adult bacteraemia (sepsis) and is the second most common cause of neonatal
meningitis.
Six per cent of the meat products contained
uropathogenic (UPEC) E. coli – UPEC
is part of the ExPEC group; these possess specific virulence traits that allow
them to cause UTIs.
One per cent of the meat products
contained E. coli harbouring the mcr-1 gene. This gene confers resistance to
colistin, an antibiotic of last resort used to treat infections caused by
bacteria resistant to all other antibiotics.
The study’s authors, who in a previous study
reported high levels of bacteria that were potentially capable of causing
severe human infections and/or multidrug resistant in chicken and turkey1, say that their latest research shows that
consumers may also be exposed to these bacteria through beef and pork.
They are calling for regular assessment of
levels of antibiotic-resistant bacteria, including ExPEC E. coli, in meat products.
Dr Mora adds: “Farm-to-fork interventions
must be a priority to protect the consumer. For example, implementation of
surveillance lab methods to allow further study of high-risk bacteria (in farm
animals and meat) and their evolution due to the latest EU restriction
programmes on antibiotic use in veterinary medicine.
“Strategies at farm level, such as vaccines,
to reduce the presence of specific multidrug-resistant and pathogenic bacteria
in food-producing animals, which would reduce the meat carriage and consumer
risk.
“The consumer plays a key role in food safety
through proper food handling. Advice to consumers includes not breaking the
cold chain from the supermarket to home, cooking meat thoroughly, storing it
properly in the refrigerator and disinfecting knives, chopping boards and other
cooking utensils used to prepare raw meat appropriately to avoid
cross-contamination. With these measures, eating meat becomes a pleasure and
zero risk.”
Reference: “Microbiological risk assessment
of Turkey and chicken meat for consumer: Significant differences regarding
multidrug resistance, mcr or presence of hybrid aEPEC/ExPEC pathotypes of E. coli” by Dafne Díaz-Jiménez, Isidro García-Meniño,
Alexandra Herrera, Luz Lestón and Azucena Mora, 19 October 2020, Food Control.
DOI: 10.1016/j.foodcont.2020.107713
