An Overview of the Impact of Pharmaceuticals on Aquatic Microbial Communities

Abstract

Pharmaceuticals are present as pollutants in several ecosystems worldwide. Despite the reduced concentrations at which they are detected, their negative impact on natural biota constitutes a global concern. The consequences of pharmaceuticals' presence in water sources and food have been evaluated with a higher detail for human health. However, although most of the pharmaceuticals detected in the environment had not been designed to act against microorganisms, it is of utmost importance to understand their impact on the environmental native microbiota. Microbial communities can suffer serious consequences from the presence of pharmaceuticals as pollutants in the environment, which may directly impact public health and ecosystem equilibrium. Among this class of pollutants, the ones that have been studied in more detail are antibiotics. This work aims to provide an overview of the impacts of different pharmaceuticals on environmental biofilms, more specifically in biofilms from aquatic ecosystems and engineered water systems. The alterations caused in the biofilm function and characteristics, as well as bacteria antimicrobial tolerance and consequently the associated risks for public health, are also reviewed. Despite the information already available on this topic, the need for additional data urges the assessment of emerging pollutants on microbial communities and the potential public health impacts.

Keywords: antimicrobial resistance; biofilms; ecological interactions; emerging contaminants; microbial diversity; one health; virulence.

Figure 1

Publications reporting the occurrence of ECs in different water systems from 2000–Present (■—groundwater; ■—drinking water or tap water; ■—wastewater; ■—surface water; ■—seawater).

Figure 2

Overview of ECs sources and transport to point-of-use: Anthropogenic activities (coming from human and animal consumption and excretion; hospital waste; industrial discharge; untreated or inefficiently treated wastewater; direct disposal; landfill leaching; agricultural activities; runoff [43,44]) are the main sources of emission of these pollutants, that are not currently monitored and are usually detected at trace level concentrations in the environment. Contaminated water resources are the source of EC presence in DW, as the equipment used in WTPs does not remove these contaminants and results in treated water being redirected to DWDS. Finally, the consumer is exposed to ECs.