Why the pork you eat could make you ‘resistant’ to some drugs

Roast pork.

Roast pork.

Photo credit: Shutterstock

It is almost inconceivable for one to think of how the pig, whose meat they enjoy eating, was raised, or treated, when it fell sick.

If antibiotics were involved, scientists warn that you are likely to get superbugs from such meat and they will make your infections resistant to some antibiotics.

Superbugs are different viruses or bacteria that are resistant to most of the available antibiotics, which are drugs used to treat a number of diseases.

In January this year, a global study published by the Lancet found out that antimicrobial resistance is now the leading cause of death, surpassing malaria and HIV/Aids.

A new study that was presented by scientists at the ongoing European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Lisbon, Portugal, has revealed that the pigs in the study had a bacterium called Clostridioides difficile which is resistant to all except three antibiotics available globally. More worrying is that the bacterium can be passed to human beings.

The researchers studied the prevalence of the bacterium in both pigs and human beings by investigating cases of patients whose infections were resistant to some antibiotics in hospitals, and identifying pigs with the said bacterium.

Of the 514 pigs that were being investigated from 14 farms in Denmark, 330 samples of the bacterium were drawn from sows (young female pig), piglets and the others from slaughtered pigs.

“Samples were screened for the presence of C. difficile and genetic sequencing was used to identify whether they harboured toxin and drug resistance genes. Genome sequencing was also used to compare the C. difficile isolates from the pig samples to 934 isolates collected from patients with C. difficile infection over the same period,” says a press statement from the researchers.

Misuse of drugs 

“Our finding of multiple and shared resistance genes indicate that C. difficile is a reservoir of antimicrobial resistance genes that can be exchanged between animals and humans,” says Dr Semeh Bejaoui, lead researcher from the University of Copenhagen.

“This alarming discovery suggests that resistance to antibiotics can spread more widely than previously thought, and confirms links in the resistance chain leading from farm animals to humans,” he added.

 Dr Edward Okoth, a senior scientist and epidemiologist at the International Livestock Research Institute (Ilri), who was not part of the study, affirms that misuse of drugs in animals is a ticking time bomb for antimicrobial resistance.

“Resistance to drugs in both humans and animals is caused by a lot of things and low dosage of antibiotics is one of those reasons. If you administer lower than the recommended dosage level of antibiotics to an animal like a pig, you give the pathogens (disease causing microorganism) an ability to circumvent the disease and get away with it. When this happens for a long time, the drug becomes ineffective to the animal,” he explains.

“People should also understand the withdrawal period, which means that animals which have been treated with antibiotics should not be slaughtered for human consumption until a certain time lapses. When people consume meat from such an animal, they end up taking in the antibiotics indirectly, and worse, at low dosage which can make them have antimicrobial resistance,” he adds.

Dr Okoth explains that pigs are not the only source of indirect antibiotics consumption to humans. Poultry is also to blame.

Drug formulation

“It is only that most of the drug formulation of poultry is given in their feed and not directly as an injection. This means that you are not likely to regulate how much of the drug they take in. When people take meat from the poultry, the same predicament of low dosage of antibiotics will befall them and the pathogens will get used to those drugs over time,” he explains.

Separating meat that has antibiotics and that which is safe for human consumption has to be done in a laboratory.

“Unfortunately, this is mostly done in the formal sector and rarely in the informal sector," he tells the Nation.

In a press statement, Dr Bejaoui, of the Denmark study, explains that in as much as the study has proven superbugs can jump from pigs to humans, the researchers could not point out how that happens.

 “The fact that some of the strains in both human and animal isolates were identical suggests that they could be shared between groups, but until we perform deeper phylogenetic analyses, we cannot determine the direction of the transmission, which could also be bidirectional, with the bacteria being continuously exchanged and expanded in the community and farms,” he said.


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