Areas subject to air pollution contain a growing concentration of bacteria that are resistant to antimicrobials, according to a new study. Consequently, air movement may provide a new ways for their transmission.
The study, highlighting a growth in airborne or air-carried antimicrobial resistant bacteria, has come from China, with a focus on the Beijing. The extent of antimicrobial resistance has been assessed at the genetic level, with the detection of DNA from genes that make bacteria resistant.
The study has been led by Professor Joakim Larsson, of the Sahlgrenska Academy and the University of Gothenburg. Professor Larsson is especially concerned about air as a potential vector for spreading antimicrobial resistant pathogens.
Antimicrobial resistance (including resistance to antibiotics) is the biggest risk faced by human societies. The implications are that life expectancy could fall due to people dying from diseases that are readily treatable today.
With the new research, Professor Larsson’s team tested air samples for genes that make bacteria resistant to antibiotics. From a total of 864 samples, DNA was tested and related back to its source. One area of concern was the detection of a series of genes that provide resistance to carbapenems. These are a group of ‘last resort antibiotics’ and they are administered for infections caused by bacteria that the most resistant to antimicrobials. Carbapenems are members of the beta lactam class of antibiotics, which kill bacteria by binding to penicillin-binding proteins and inhibiting cell wall synthesis.
Importantly, the findings cannot indicate if the bacteria are alive in the air. This narrows the risk somewhat; however, the potential for genetic transfer with viable bacteria, upon contact, remains.
The study is, however, only a starting point. The researchers plan to assess whether antimicrobial resistance can indeed spread through air. Here the focus will move to a study of the air within the vicinity of European sewage treatment plants. Sewage plants are regularly called out as potential sites for the spread of antimicrobial resistance. This is because, with so many different types of bacteria coming together in sewage plants, this provided optimal conditions for organisms to swap genes that confer resistance. This also means antibiotic-resistant bacteria could evolve much faster than they would in isolation.
Data will be cross-checked in relation to the air and to the sewage. Additional samples will be taken from people who live in close proximity to sewage plants.
The research findings are published in the journal Microbiome and the research paper is titled “The structure and diversity of human, animal and environmental resistomes.”