Environmental dissemination of antibiotic resistance genes and correlation to anthropogenic contamination with antibiotics

Abstract

Antibiotic resistance is a growing problem which threatens modern healthcare globally. Resistance has traditionally been viewed as a clinical problem, but recently non-clinical environments have been highlighted as an important factor in the dissemination of antibiotic resistance genes (ARGs). Horizontal gene transfer (HGT) events are likely to be common in aquatic environments; integrons in particular are well suited for mediating environmental dissemination of ARGs. A growing body of evidence suggests that ARGs are ubiquitous in natural environments. Particularly, elevated levels of ARGs and integrons in aquatic environments are correlated to proximity to anthropogenic activities. The source of this increase is likely to be routine discharge of antibiotics and resistance genes, for example, via wastewater or run-off from livestock facilities and agriculture. While very high levels of antibiotic contamination are likely to select for resistant bacteria directly, the role of sub-inhibitory concentrations of antibiotics in environmental antibiotic resistance dissemination remains unclear. In vitro studies have shown that low levels of antibiotics can select for resistant mutants and also facilitate HGT, indicating the need for caution. Overall, it is becoming increasingly clear that the environment plays an important role in dissemination of antibiotic resistance; further studies are needed to elucidate key aspects of this process. Importantly, the levels of environmental antibiotic contamination at which resistant bacteria are selected for and HGT is facilitated at should be determined. This would enable better risk analyses and facilitate measures for preventing dissemination and development of antibiotic resistance in the environment.

Fate of antibiotic resistance genes and its drivers during anaerobic co-digestion of food waste and sewage sludge based on microwave pretreatment

“…It has been estimated that antibiotic resistance is responsible for more than 25,000, 23,000, and 38,000 deaths every year in the European Union, the United States, and Thailand, respectively (Berglund, 2015). This highlights the need for broad strategies to slow the rate at which resistance spreads, and proactive treatment of anthropogenic waste containing ARGs may help mitigate the spread of ARGs (Pruden et al, 2013).…”

Ecological and Public Health Implications of the Discharge of Multidrug-Resistant Bacteria and Physicochemical Contaminants from Treated Wastewater Effluents in the Eastern Cape, South Africa

“…This presents a serious challenge worldwide, with severe implications for morbidity and mortality both in clinical and community settings. Wastewater treatment facilities are significant "hotspots" for the emergence and spread of clinically important antibiotic resistant genes [15,16]. Antibiotics and other pharmaceuticals residues have been detected in municipal effluents worldwide.…”

Biofilm Formation in Bacillus cereus, B. licheniformis and B. pumilus: An Alternative for Survival in Impacted Environments

“…The urban dejects that are launched in aquatic environments attract decomposing microorganisms, causing ecological imbalances by reducing the oxygen present in the water as well as changes in the dynamics of these ecosystems (Freitas and Gaudio, 2015). The contamination of water bodies by resistant bacteria pathogenic to humans and other animals is another problem that affects these environments (Nascimento and Araújo, 2013;Berglund, 2015). According to the World Health Organization (2016), approximately a half of the population living at the developing world will be affected by infections directly related to water that is out of quality standards and due to inadequate or non-existent sanitation.…”