Environment Affects How Superbugs Move Around

In a new investigation on the spread and infection patterns displayed by antibiotic resistant bacteria – commonly known as superbugs – researchers discovered that their prevalence was higher in villages located along roads than in settlements that were out of reach, or difficult to get to.

This appears to suggest that roads played a never-before-considered role in helping superbugs such as antibiotic-resistant Escherichia Coli (E. coli) spread throughout the general population. The new findings confirm previous studies that roads favor the spread of diseases.

However, what the other researches did not evidence was a connection between proximity to a road and the chances a person has of being exposed to antibiotic-resistant bacteria. This study was carried out by researchers at the University of Michigan (U-M) School of Public Health.

Details of the new work were published in a paper called “In-roads to the spread of antibiotic resistance: regional patterns of microbial transmission in northern coastal Ecuador,” which is published in this month's issue of the Journal of the Royal Society, Interface.

U-M professor Hoe Eisenberg was the leader of the research team, which also included colleagues from the Universidad San Francisco de Quito, and Trinity College. He is also a coauthor of the new study.

The study took experts in the northwestern regions of Ecuador. Over a period of five years, the team carried out tests on available strains of antibiotic-resistant E. coli, using a combination of ampicillin and sulfamethoxazole as treatments.

“Our results show it's not just the individual's antibiotic use that affects antibiotic resistance,” the U-M investigator explains. He says that roads provide two factors that tip the scales in the bacteria's favor.

“Important factors that affect the spread of antibiotic resistance are the rates at which people introduce new strains due to movement in and out of the region, as well as poor water quality and sanitation that allow for the transmission of antibiotic resistant strains,” he explains.

This is one of the few studies conducted to date that also takes into account the broader environmental and social context governing the development of resistance to antibiotics in bacteria. Thus far, a lot of emphasis was placed on the individual, and the way in which they consume antibiotics.

“If we want to think about how we deal with antibiotic resistance we have got to think about the broader environmental forces that cause the spread of antibiotic resistance, in addition to how doctors prescribe antibiotics to individuals,” Eisenberg explains.