Wastewater

Wastewater is a sink for human activities and contains resistance genes from human feces, farms, households and hospitals. Treated wastewaters often are released into surface waters such as rivers, which are used for recreational activities like sports, fishing and swimming. A cross-sectional study revealed that the gut of surfers is three to four times more likely to be colonized by multi-drug resistant microbes compared to the gut of non-surfers.

In addition, potable water is obtained from treated surface or groundwater. Research has shown that drinking water biofilms (aggregation of microbes living on surfaces) can transfer antimicrobial resistance genes to the mouse gut, indicating that they might also be transferred to the human gut.

Food

To increase animal productivity, antimicrobials are often applied on farms, and this can lead to the selection and development of resistance genes. The application of animal manure and sludge (byproduct of wastewater treatment) in agriculture can mediate the transfer of antimicrobial resistance genes to food crops. Several ARGs have been found to travel from soil to edible parts of plants such as tomato, lettuce and broad bean crops.

Air

Inhalable antimicrobial resistance genes pose an increasingly growing silent health threat. Recent reports from hospital samples have revealed that the daily human exposure to resistant bacteria contained in aerosols is 10 times higher than those present in drinking water.

Health-care facilities

Health-care facilities are one of the most prominent locations for acquiring multi-drug resistant infections due to the presence of opportunistic pathogens that infect immunologically compromised patients. Presence of antimicrobials further aid in the development and selection of resistant microbes, which then can be transferred from one patient to others by interpersonal contact or via common surfaces such as door handles, bed rails or lockers.

Travel

International travellers who travelled to developing countries have been found to acquire multi-drug resistant bacteria. They may have acquired these microbes via contaminated food and water, due to poor hygiene practices or because of differential antimicrobial usage policies across countries

Source: thehindu.com