Sanitation and health of populations key to the global fight against antibiotic resistance
The University of Helsinki took part in an international research project encompassing 60 countries where the bacterial resistance of healthy populations to antibiotics was investigated through the study of sewage. The study revealed that the health and level of hygiene of the population of individual countries are new variables associated with bacteria resistant to antibiotics.

The study is the first of its kind to produce globally comparable data relating to the antibiotic resistance of healthy populations in 60 countries and 79 cities. The researchers mapped out the current situation by using bacteria found in municipal wastewater. The research focused on bacterial genes identified in the DNA sequences of bacterial genomes, which shed light on the ability of bacteria to resist various antibiotics.  

“Reliable information on the antibiotic resistance of healthy populations has been difficult to obtain. However, by studying urban sewage we gained new information on the abundance of bacteria resistant to antibiotics at the level of societies. We studied samples collected from the Viikinmäki wastewater treatment plant in Helsinki, and it’s safe to say that the situation in Finland and Helsinki is very good: the prevalence of antibiotic resistance is low,” says researcher Annamari Heikinheimo from the Faculty of Veterinary Medicine, University of Helsinki.   

The researchers collected samples from untreated sewage in the target cities and extracted the DNA material found in them, looking for DNA sequences belonging to the genes of bacteria resistant to antibiotics. Indeed, the researchers recommend employing this method, known as metagenomic analysis, as it is an ethical and inexpensive way of monitoring and predicting antibiotic resistance on a global scale. 

As regards the number of genes belonging to bacteria resistant to antibiotics, the countries under investigation were divided into two groups: the lowest frequencies of antibiotic resistance were found in Western Europe, North America, Australia and New Zealand, while the highest concentrations were observed in Asia, Africa and South America. The widest range of genes from bacteria resistant to antibiotics was found in Brazil, India and Vietnam, the narrowest in Australia and New Zealand. 

Abundant consumption of drugs not the only explanation for bacterial resistance to antibiotics 

The research project compared the prevalence of antibiotic resistance to the consumption of antibiotics, as well as to socioeconomic and health indicators describing the state of the environment collected by the World Bank.  

“Moderate antibiotic consumption is considered one of the most important factors in preventing the rise of antibiotic resistance. However, drug consumption only partially accounted for the prevalence of antimicrobial resistance found in the study,” Heikinheimo points out.  

Several variables associated with the presence of genes belonging to bacteria resistant to antibiotics had a link to the level of hygiene in the country in question, as well as to the general health and socioeconomic status of its population. What kinds of measures do the researchers recommend for the regions where antibiotic resistance is an everyday occurrence? 

“Globally, the prevention of antibiotic resistance should involve measures to improve hygiene in the countries where antibiotic resistance is abundant, for example, by improving sanitation. Investment in the training of physicians also seems to pay off in the fight against antibiotic resistance, as the number of physicians active in a country was found to be a factor related to low frequencies of antibiotic resistance,” Heikinheimo says.  

The project results indicate that controlling antibiotic resistance is also essential to the sustainable development goals of the United Nations.  

The project was funded by the Novo Nordisk Foundation, the Velux Foundation and the EU project COMPARE.

Original article: 
Global monitoring of antimicrobial resistance based on metagenomics analyses of urban sewage 
Nature Communications, 8 March 2019, doi 10.1038/s41467-019-08853-3 

Further information: 
Frank Aarestrup, project leader, professor, fmaa@food.dtu.dk, phone +45 35 886 281 

See also: 
Zoonotic antimicrobial resistance research group