Environmental Distribution of AR Class 1 Integrons in Upper Adige River Catchment (Northern Italy)

• Main Authors: Federica Piergiacomo, Luigimaria Borruso, Sonia Ciccazzo, Stefano Rizzi, Stefan Zerbe, Lorenzo Brusetti
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: <i>intl1</i>; gene cassettes; antibiotic resistance; public health; bioindicators; land use
• Online Access: https://www.mdpi.com/1660-4601/17/7/2336
• ISSN: 1661-7827; 1660-4601

The source of antibiotic residuals can be directly related to the presence of municipal or industrial wastewater and agricultural activities. Antibiotics can trigger the dissemination of antibiotic resistance genes within bacterial communities. The mobile genetic elements Class 1 integrons (<i>intl1</i> region) has been already found to be correlated with a wide range of pollutants (i.e., antibiotics, heavy metals), and hence, it has been proposed as a proxy for environmental health. This study aimed to assess the presence of <i>intl1</i> in different environmental matrices, including agricultural and forest soils, freshwater and unpolluted sediments in the upper Adige River catchment (N Italy), in order to identify the spread of pollutants. <i>Intl1</i> was detected by direct PCR amplification at different frequencies. The urban and agricultural areas revealed the presence of <i>intl1</i>, except for apple orchards, where it was below the detection limit. Interestingly, <i>intl1</i> was found in a presumed unpolluted environment (glacier moraine), maybe because of the high concentration of metal ions in the mineral soil. Finally, <i>intl1</i> was absent in forest fresh-leaf litter samples and occurred with low rates in soil. Our results provide new data in supporting the use of <i>intl1</i> to detect the environmental health of different land-use systems.