Triclosan Alters Microbial Communities in Freshwater Microcosms

Abstract

The effect of triclosan on microbial communities that are found in soil and sediments is well documented. However, little is known regarding the possible effects of triclosan on microbial communities that are present in the column of freshwater streams as the antimicrobial is released from sediments or from water sewage outflow. We show that a concentration of triclosan as low as 1 ng/L decreases richness and evenness in freshwater microbial communities growing in the water column while using controlled experimental microcosms. Crucially, the decrease in evenness that was observed in the microbial communities was due to the selection of bacteria commonly associated with human activity, such as Acinetobacter, Pseudomonas, and Rhodobacter, as opposed to an increase in Cyanobacteria, as previously suggested. Finally, our results demonstrate that higher concentrations of triclosan comparable to heavily polluted environments can also impact the overall phylogenetic structure and community composition of microbial communities. Understanding the impact of triclosan on these microbial populations is crucial from a public health perspective as human populations are more often exposed to microbial communities that are present in the water column via recreative use.

Bacterial ecotoxicity and shifts in bacterial communities associated with the removal of ibuprofen, diclofenac and triclosan in biopurification systems

“…Recent studies have demonstrated that TCS is an environmental stressor, alters the community structure and reduces species diversity and richness (Clarke et al, 2019;Oh et al, 2019;Peng et al, 2019). The simultaneous treatment with the three PPCPs gave alpha diversity values generally lower than those obtained for IBP and DCF, and higher than for TCS alone, but not significantly different from the controls, except for a higher evenness after 7 days.…”

Structure of Bacterial Community with Resistance to Antibiotics in Aquatic Environments. A Systematic Review

“…Of these, there were 128 duplicates, and 16,013 were excluded on the basis of title and abstract screening. A total of 68 studies [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , ...…”

“…The majority of ARGs reported are those that confer resistance to β-lactam antibiotics, aminoglycosides, fluoroquinolones and macrolides. However, of the studies, 12 (17.6%) did not have precise information on the types of ARGs found, as is the case for the reports made by Port et al [ 27 ], Han et al [ 48 ], Fang et al [ 51 ], Pan et al [ 54 ], Chen et al [ 55 ], Eduardo-Correia et al [ 57 ], Quintela-Baluja [ 42 ], Clarke et al [ 61 ], Fernandes Cardoso de Oliveira et al [ 62 ], Coutinho et al [ 45 ], Miranda et al [ 63 ], Lu et al [ 64 ], Jiang et al [ 65 ], and Qu et al [ 66 ].…”

“…In relation to the reports of bla genes in artificial waters, in North America, bla CTX , bla GES , bla NDM , bla VIM , bla SHV , bla OXA , bla MOX , bla KPC , bla IMP and bla TEM genes were identified in WWTP effluents [ 76 ], and in Europe, the bla VIM gene (12%) was the most prevalent [ 11 , 48 ]. In Asia, a higher abundance of bla TEM (33%) was detected, followed by bla KPC (22%) in water samples from WWTP and aquaculture [ 36 , 38 , 73 ], while in Latin American countries, bla CTX (25%) and bla TEM (25%) were the most prevalent [ 15 , 43 , 44 , 61 ]. No studies were found reporting on these genes in artificial waters from Africa.…”

“…The increasing anthropogenic and industrial activity near or directly in water systems has contributed to the growth and strengthening of the bacterial resistome [ 7 , 9 , 41 , 61 ]. There is no doubt that aquatic environments act as reservoirs for the acquisition and spread of bacteria with resistance to antibiotics, so human exposure to bacteria resistant to antibiotics and ARGs from these environments may represent an additional risk to health.…”