Urbanization promotes specific bacteria in freshwater microbiomes including potential pathogens

Bacterial composition in Swedish raw drinking water reveals three major interacting ubiquitous metacommunities

“…The core microbiome was dominated by representatives within the families of Rhodobacteraceae, Puniceicoccaceae, Sphingomonadaceae, Opitutaceae, Rickettsiaceae, and Microbacteriaceae, with some of the other representative taxa present only at very low abundances, which suggests that the core microbiome consists of generalists that occur within a stable span in frequency, and that this pattern reflects a life‐strategy more oriented towards changing conditions and an opportunistic lifestyle. Our finding that there exist well‐defined core taxa among the different sampling sites, coupled with the results of others (Llirós et al, 2014; Newton & McLellan, 2015; Numberger et al, 2020), suggest that the observed genera contain species with a mixture of oligotrophic and eutrophic preferred conditions. Thus, a plausible conclusion is that within‐genus lifestyle specialization is actively shaping the community composition of freshwater in anthropogenic affected areas.…”

“…Other studies have reported a correlation of genera within phyla Proteobacteria and Bacteroidetes to increased nutrient levels, which comes with increased anthropogenic activity, both in microcosms and in lake systems (e.g., Andersson et al, 2018; Buelow et al, 2016; Fisher et al, 2015). Newton and McLellan (2015) found an elevated abundance of the genera Limnohabitans, Polynucleobacter, and Rhodobacter in the urbanized site (urban estuary of Milwaukee), while Numberger et al (2020) found enriched levels of bacterial families with possible association to fecally contaminated water in urban affected lakes in Brandenburg, Germany, such as Bacteroidaceae, Prevotellaceae, Rikenellaceae, Tannerellaceae, and Weeksellaceae, and defined these as an urban bacterial fingerprint.…”

Gut Bacterial Communities Vary across Habitats and Their Diversity Increases with Increasing Glucocorticoids in Toad Tadpoles

“…Similarly to many species of vertebrates including amphibians, we found that the most abundant phyla of intestinal bacteria were Firmicutes, Proteobacteria and Bacteroidota (amphibians: [39,45,74,75], review of vertebrates: [37]. Bacteroidota and Firmicutes are considered more pathogenic bacteria and are associated with the breakdown of organic matter; an earlier study found that these taxa are more abundant in urban lakes [24]. Similar differences may account for the distinct gut bacterial communities we found here, although we have no data on the aquatic microbial communities inhabiting our study sites.…”

“…Agricultural and urban land use alter environments via an increase in chemical pollutants and multiple other factors associated with anthropogenic areas including urban heat island effects [21] and altered environmental and host microbiomes [9,22] Much of this knowledge on wildlife microbiome comes from terrestrial animals [23] while aquatic organisms are relatively under-studied in this regard. Anthropogenic influences on urban aquatic habitats include introduction of sewage water, fecal matter from terrestrial mammals, and pollutants from urban storm water run-off which lead to eutrophication [24][25][26]. In habitats altered for crop production, organisms living in adjacent water bodies are exposed to agrochemicals, nutrients, wastewater and even manure wastes associated with agricultural Diversity 2023, 15, 23 2 of 13 run-off [27][28][29].…”

“…In habitats altered for crop production, organisms living in adjacent water bodies are exposed to agrochemicals, nutrients, wastewater and even manure wastes associated with agricultural Diversity 2023, 15, 23 2 of 13 run-off [27][28][29]. These changes in land use alter the environmental microbial communities in soil and water [24][25][26]. In turn, anthropogenically altered environmental bacterial communities create a potential health risk to aquatic organisms, likely associated with the greater decline in biodiversity observed in freshwater environments than in terrestrial environments [30].…”