Identifying hotspots for antibiotic resistance emergence and selection, and elucidating pathways to human exposure: Application of a systems-thinking approach to aquaculture systems

Abstract

Aquaculture systems are highly complex, dynamic and interconnected systems influenced by environmental, biological, cultural, socio-economic and human behavioural factors. Intensification of aquaculture production is likely to drive indiscriminate use of antibiotics to treat or prevent disease and increase productivity, often to compensate for management and husbandry deficiencies. Surveillance or monitoring of antibiotic usage (ABU) and antibiotic resistance (ABR) is often lacking or absent. Consequently, there are knowledge gaps for the risk of ABR emergence and human exposure to ABR in these systems and the wider environment. The aim of this study was to use a systems-thinking approach to map two aquaculture systems in Vietnam – striped catfish and white-leg shrimp – to identify hotspots for emergence and selection of resistance, and human exposure to antibiotics and antibiotic-resistant bacteria. System mapping was conducted by stakeholders at an interdisciplinary workshop in Hanoi, Vietnam during January 2018, and the maps generated were refined until consensus. Thereafter, literature was reviewed to complement and cross-reference information and to validate the final maps. The maps and component interactions with the environment revealed the grow-out phase, where juveniles are cultured to harvest size, to be a key hotspot for emergence of ABR in both systems due to direct and indirect ABU, exposure to water contaminated with antibiotics and antibiotic-resistant bacteria, and duration of this stage. The pathways for human exposure to antibiotics and ABR were characterised as: occupational (on-farm and at different handling points along the value chain), through consumption (bacterial contamination and residues) and by environmental routes. By using systems thinking and mapping by stakeholders to identify hotspots we demonstrate the applicability of an integrated, interdisciplinary approach to characterising ABU in aquaculture. This work provides a foundation to quantify risks at different points, understand interactions between components, and identify stakeholders who can lead and implement change.

Simple, fast and environmentally friendly method to determine ciprofloxacin in wastewater samples based on an impedimetric immunosensor

“…The curve obtained through standard addition (y ¼ 1.57 Â 10 5 [CIP] + 9.20; R 2 ¼ 0.998) enabled us to determine the CIP concentration in the wastewater samples. Considering the dilution performed previously, the CIP concentration in the wastewater sample was 2.90 Â 10 À4 mg mL À 1 .…”

“…The main consequence reported is the appearance of multi-resistant bacteria. [2][3][4][5] This microbial resistance could be caused by the overuse of antibiotics in veterinary therapy or by the presence in the environment. Thus, antibiotics in the environment are considered as a major threat to human health and aquatic ora and fauna, even at the extremely low concentrations found in the environment, such as micrograms and nanograms per liter.…”

A cellulose-based colour test-strip for equipment-free drug detection on-site: application to sulfadiazine in aquatic environment

“…However, the presence of antibiotics in the aquatic environment has been linked to episodes of resistance to pathogenic bacteria [10][11][12][13][14][15]. This is also an outcome of using the same antibiotic compounds in humans and in fish and raises serious public health concerns [16]. The antibiotics used in aquaculture belong to several groups of human use [6,17], among which sulphonamides appear as a relevant target [7,10].…”

Optimising efficacy of antibiotics against systemic infection by varying dosage quantities and times

“…Bacterial antibiotic resistance is not only of great concern for human patients, but it also has a significant impact in agriculture [9], aquaculture [10][11], horticulture [12], and the natural environment [13]. With the growth of the human population and the increased demand for animal protein in particular, the use of antibiotics in food production continues to increase [14].…”