Spread of Antibiotic Resistant Genes Among Bacteria Can be Restricted With Proper Sanitation and Water Facilities, Finds Study

Clean water and proper sanitation facilities can be very effective in curbing the rise of antibiotic resistance amongst many bacteria, especially in urban areas in Africa and Southeast Asia, a Lancet study published recently suggests. Scientists from multiple countries were involved in the study by Amy J Pickering of the University of California, Berkeley. 

Amy Pickering said, “Our study highlights the role of environmental transmission of antibiotic resistance in settings with inadequate sanitation.”

The antibiotic-resistant bacteria are those that can withstand an antibiotic treatment. Antibiotics are medicines primarily used to kill microorganisms, especially bacteria. The resistant bacteria are not affected by such drugs. 

A major global public health concern is the rise of antibiotic resistance amongst bacteria. For this, the reckless use of antibiotics has been criticised largely. It is a well-researched topic that repeated and wide use of antibiotics can confer bacteria with the ability to develop resistance against it over time. Certain genes confer the antibiotic resistance some bacteria acquire called the Antibiotic Resistance Genes (ARGs). In fact, many of the resistant bacteria causing widespread concern in clinical settings acquire it through the ARGs. 

Pathogenic bacteria are the ones that cause infection and disease in populations. Some useful bacteria reside in our body, which helps in several biochemical processes known as commensal bacteria. All pathogenic bacteria may not be antibiotic resistant, meaning they can be treated with antibiotics. But some pathogenic bacteria can acquire antibiotic resistance via the ARGs through a process known as horizontal gene transfer. 

Among the Low and Middle-Income Countries (LMICS), antibiotic-resistant bacteria have become a leading cause of death, and people in such countries bear a higher burden of bacterial infections. The spread of antibiotic resistance through the ARGs in horizontal gene transfer can further aggravate the health situation in such countries. Moreover, some of the most concerning ARGs have also emerged in the LMICS, and they can further spread to other pathogenic bacteria and help them emerge as antibiotic resistant. In this context, looking at ways to curb such ARGs' spread to other bacteria may become effective. Amy Pickering and the team looked for it. 

They found that inadequate facilities of clean drinking water, proper sanitation and hygiene among the LMICS can further complicate the health system by facilitating the spread of the ARGs. Clean water and sanitation are nearly available in most high-income countries. “Inadequate water, sanitation and hygiene (WASH) infrastructure and access could exacerbate the spread of [this] resistance,” the study says. 

For the study, the team of researchers resorted to metagenomics data. The metagenomics data refers to all of the material in a sample. The researchers focused on the metagenomes of the human faecal metagenome. The metagenomes are tagged by geospatial locations, meaning the researchers can know which part of the globe the faecal samples are coming from. Then they linked it with the household survey data, which are also geospatially tagged and the condition of sanitation and drinking water facilities in those areas. The researchers argue that the method was adopted because it can overcome the limitation in the human faecal samples taken from sewage. Many LMICS households are not at all linked to a sewage system. 

The researchers identified around 1600 human faecal metagenomes from 26 countries. The highest abundance of the ARGs was found in Africa compared to Europe, North America and Western countries, with the second highest in Southeast Asia compared to Europe and North America.

With increased facilities of clean water and sanitation, the spread of the ARGs decreased, and this relation was found to be stronger in urban setups than the rural ones. Amy Pickering commented further in this context and the heavy use of antibiotics,  "Controlling antibiotic drug consumption is likely insufficient to stop the spread of antibiotic resistance. Community environmental transmission should be given greater attention.”

Pickering, however, pointed at some limitations of the findings, “Our study is a cross-sectional analysis which can identify associations, but studies are needed to confirm that improved sanitation and water access will reduce antibiotic resistance.”