The High Risk of Bivalve Farming in Coastal Areas With Heavy Metal Pollution and Antibiotic-Resistant Bacteria: A Chilean Perspective

Abstract

Anthropogenic pollution has a huge impact on the water quality of marine ecosystems. Heavy metals and antibiotics are anthropogenic stressors that have a major effect on the health of the marine organisms. Although heavy metals are also associate with volcanic eruptions, wind erosion or evaporation, most of them come from industrial and urban waste. Such contamination, coupled to the use and subsequent misuse of antimicrobials in aquatic environments, is an important stress factor capable of affecting the marine communities in the ecosystem. Bivalves are important ecological components of the oceanic environments and can bioaccumulate pollutants during their feeding through water filtration, acting as environmental sentinels. However, heavy metals and antibiotics pollution can affect several of their physiologic and immunological processes, including their microbiome. In fact, heavy metals and antibiotics have the potential to select resistance genes in bacteria, including those that are part of the microbiota of bivalves, such as Vibrio spp. Worryingly, antibiotic-resistant phenotypes have been shown to be more tolerant to heavy metals, and vice versa, which probably occurs through co- and cross-resistance pathways. In this regard, a crucial role of heavy metal resistance genes in the spread of mobile element-mediated antibiotic resistance has been suggested. Thus, it might be expected that antibiotic resistance of Vibrio spp. associated with bivalves would be higher in contaminated environments. In this review, we focused on co-occurrence of heavy metal and antibiotic resistance in Vibrio spp. In addition, we explore the Chilean situation with respect to the contaminants described above, focusing on the main bivalves-producing region for human consumption, considering bivalves as potential vehicles of antibiotic resistance genes to humans through the ingestion of contaminated seafood.

Ecological Responses of Maize Rhizosphere to Antibiotics Entering the Agricultural System in an Area with High Arsenicals Geological Background

“…From our results, bacteria that are resistant to arsenic that forms in a high geological background may also be resistant to antibiotics, because of weak relationships with biogeochemical processes of ecosystems and antibiotics treatments in the rhizosphere ( Figure 5 ). This could be explained by the facts that soil microbial community were primarily determined by high arsenic background; and the ability of microbes in arsenic-polluted soil to co-resist, cross-resist, co-regulate, or biofilm-induce the antibiotics presence [ 62 , 63 ]. Meanwhile, organic arsenic may be a primordial antibiotic, and the host in arsenic-rich conditions can pose evolutionary dynamics of host–microbe–environment interactions and present existence of a novel detoxification and adaptation mechanism [ 64 , 65 ].…”

Misunderstandings and misinterpretations: Antimicrobial use and resistance in salmon aquaculture

“…They also overlook evidence for the presence of huge amounts of antimicrobial‐resistant bacteria in the intestines of antimicrobial‐treated salmon and other fish as well as in the marine sediments in the areas where these antimicrobials are used (Buschmann et al, 2012 ; Higuera‐Llantén et al, 2018 ) and evidence that aquaculture may be a source of antimicrobial‐resistant zoonotic pathogens (Cabello et al, 2013 ; Weir et al, 2012 ; Ziarati et al, 2022 ). In glossing over the problems of resistance and the potential for selection and ecotoxicity by antimicrobials to other living beings of the aquatic environment, some consumed by humans (Fortt et al, 2007 ; Kovalakova et al, 2020 ; Kumar et al, 2019 ; Pavón et al, 2022 ), Avendaño‐Herrera et al hope to provide support for the expansion of their use in this activity.…”

“…One approach to correcting these shortcomings would involve quantitating antimicrobial‐resistant bacteria and antimicrobial resistance genes in commercially available salmon fillets and then comparing DNA sequences of the resistome and mobilome of these bacteria with those of the total aquatic environment (including fish) and those of commensals and pathogens of the human intestinal microbiome in people who consumed such fillets (Aguiar‐Pulido et al, 2016 ; Bengtsson‐Palme et al, 2017 ; Tümmler, 2020 ; Waskito et al, 2022 ). Neither Avendaño‐Herrera et al, nor Salgado‐Caxito et al, discuss the food safety risk that this antimicrobial use generates by contaminating other aquacultural products such as mussels and wild fish with antimicrobial residues and antimicrobial‐resistant bacteria (Fortt et al, 2007 ; Pavón et al, 2022 ; Ramírez et al, 2022 ).…”

Antibiotic and Heavy Metal Co-Resistant Strain Isolated from Enrichment Culture of Marine Sediments, with Potential for Environmental Bioremediation Applications

“…Growth at different temperatures (4,15,20,28,30,35,37,40,42, and 45 • C) was tested for approximately 7 days on MA medium (growth was recorded every 4 h). Salt tolerance was determined using modified MA (prepared according to the MA formula, but without NaCl) with various concentrations of NaCl (0-20% at 0.5% intervals, w/v).…”

“…The resistance and accumulation capacity of the bacteria ensures that they can be used for the bioremediation of contaminated environments. Antibiotic resistance genes in bacteria arise from the selective pressure or horizontal gene transfer (HGT) of antibiotics [ 29 ], and heavy metals can enhance selection for antibiotic resistance in the environment [ 30 ]. HGT carries the risk of spreading resistance [ 31 ], which needs to be taken into account.…”