SAN FRANCISCO (XINHUA) - Antibiotic-resistant bacteria could be transmitted to humans through consumption of plant foods, which may pose health risks for the general public, according to a study unveiled on Saturday (June 22).

Researchers at the University of Southern California (USC) discovered how plant foods serve as vehicles for spreading antibiotic resistance to the gut microbiome, said a study presented to ASM Microbe 2019, an annual meeting of the American Society for Microbiology (ASM) being held here from June 20 to 24.

During a mouse experiment, the scientists observed that antibiotic bacteria or superbugs successfully hid in the intestines of the mice fed with lettuce contaminated with the antibiotic-resistant bacteria of E. coli.

"We found differences in the ability of bacteria to silently colonise the gut after ingestion, depending on a variety of host and bacterial factors," said USC researcher Marlene Maeusli, who is also the lead author on the study.

Unlike the outbreaks of diarrhoeal illnesses caused immediately after humans eat contaminated vegetables, the antibiotic-resistant bacteria can hide in the human intestines for months or even years before they cause an illness such as a urinary infection, said the study.

"Our findings highlight the importance of tackling food-borne antibiotic-resistance from a complete food chain perspective that includes plant-foods in addition to meat," Ms Maeusli said.

About two million cases of antibiotic-resistant infections occur every year in the United States and 20 per cent of them are linked to agriculture, according to the estimates of the US Centres for Disease Control and Prevention.