Urban microbes are adapting to resist disinfectants.

The coronavirus pandemic has prompted people to use disinfectants more often. However, efforts to create a sterile urban environment may backfire. This is evidenced by the results of a new study by scientists from Xi’an Jiaotong-Liverpool University (China), the university’s press service reports.

Scientists have discovered new strains of microbes that have adapted to use the limited resources available in cities.

Anthropogenic environments have special conditions that distinguish them from natural and artificial habitats, scientists note.

Areas with many buildings contain little of the traditional nutrients and essential resources microbes need to survive, so these built environments have a unique microbiome.

Our use of detergents and other industrial products creates a unique environment that places selective pressure on microbes to adapt or disappear, but the mechanisms by which microbes adapt and survive in the built environment are not well understood, the researchers note.

For the study, the researchers collected 738 samples from a variety of built environments, including subways, residential buildings, public facilities, piers and human skin in Hong Kong. They then used metagenomic sequencing to analyze the genomic content of the microbes and understand how they adapted to complex urban environments.

As a result:

• scientists have identified 363 strains of previously unidentified microorganisms that live on human skin and in the environment;
• the genomes of some of these strains contained genes for metabolizing industrial products found in cities and using them as sources of carbon and energy;
• in particular, a strain of Candidatus phylum Eremiobacterota was discovered, which had previously been found only in the soil of Antarctic deserts. The genome of this new strain of Eremiobacterota allows it to metabolize ammonium ions found in detergents. The strain also has alcohol and aldehyde dehydrogenase genes to break down residual alcohol found in common disinfectants.

Scientists note that microbes with an increased ability to use limited resources and transport industrial products such as disinfectants and metals outpace unstable strains, enhancing their survival and evolution in the built environment. Therefore, they may pose a health risk if they are pathogenic.

Thus, the team of researchers identified 11 unique, previously undescribed strains of Micrococcus luteus, which are usually not pathogenic, but can cause opportunistic infections in people with weakened immune systems.

The issue of their adaptation to our behavior takes on particular importance in clinical settings, where hospitals serve as hot spots for various pathogens that cause hospital-acquired infections (HAIs). Nosocomial infections pose a significant threat, especially in intensive care units, where mortality rates can reach 30%, the scientists note.

The researchers also discovered two new strains of Patescibacteria, known as “nanobacteria” because they have tiny genomes that don’t contain many genes to produce their own resources.

Some strains of Patescibacteria are considered parasitic because they rely on bacterial hosts to supply their nutrients.

However, in this study, scientists discovered that one of the strains of nanobacteria extracted from human skin contained genes for the biosynthesis of carotenoids and ubiquinone. These antioxidant compounds are vital for humans, and we typically obtain them, especially carotenoids, from our diet, suggesting a possible mutualistic relationship between bacteria and us as their hosts, the researchers note.

The team is now investigating the transmission and evolution of resistance of pathogenic microbes in intensive care units exposed to stringent and extensive disinfection methods. They hope to improve infection control practices and make the clinical environment safer for healthcare workers and patients.

Source: Racurs

David

I am David Wyatt, a professional writer and journalist for Buna Times. I specialize in the world section of news coverage, where I bring to light stories and issues that affect us globally. As a graduate of Journalism, I have always had the passion to spread knowledge through writing.