Exotic veggies could contain drug-resistant germs

The exotic aisle in the supermarket could potentially harbour drug-resistant bacteria Keystone

Researchers at the University of Zurich have found antibiotic-resistant bacteria in fresh vegetables imported from India, Thailand, Vietnam and the Dominican Republic. This has raised public health concerns among the Swiss population.

A quarter of the 169 vegetable samples imported into Switzerland from the four countries revealed one or more extended-spectrum beta-lactamase (ESBL) producing bacteria called Enterobacteriaceae. Beta-lactamase provides antibiotic resistance by breaking down the antibiotics’ structure.

Another cause for worry is that over 78% of the bacteria were multi-drug resistant, according to the scientific study published in February.

This week, an analysis commissioned by Swiss public television SRF’s consumer protection programme “Kassensturz” also showed similar results. Of the 33 samples of fresh vegetable produce originating from India, Vietnam and Thailand, a third were found to contain antibiotic-resistant bacteria including okra, aubergines, coriander and Thai basil.  All the products tested came from supermarkets or speciality stores in Switzerland.

The consumer programme also clarified that the dangerous bacteria are neutralised during cooking. However, herbs like coriander and Thai basil were deemed to be particularly risky because they are usually consumed raw.

Threat to public health

The researchers agree that the pathogenic bacteria present in exotic vegetables constitute a threat to public health. The scientific studyExternal link found a highly virulent pandemic E. coli bacteria strain, which is associated with severe infections in humans. They also found two other E.coli strains “that cause urinary tract infections in humans and contribute to the global dissemination of ESBLs and multi drug-resistant genes”.

The scientist warned that exotic vegetables like the ones analysed in the study “represent another potent and hitherto underappreciated source of antibiotic resistance genes”.