Antibiotic manufacturing effluent enriches resistance genes and alter the structure of microbial communities. CROATIA

In this work, we have examined sludge samples from a Croatian azithromycin production plant using shotgun metagenomics, to better understand the full diversity of known resistance genes, mobile genetic elements and the impact on taxonomic composition caused by extensive antibiotic selection pressures. We compare this data to sludge from a wastewater treatment plant receiving municipal sewage. We find that the sludge from pharmaceutical production harbors around three times as much resistance genes as the municipal sewage sludge, with particularly large enrichments of aminoglycoside, amphenicol and sulfonamide resistance genes. The findings highlight that antibiotic production does contribute to the development of antibiotic resistance also in European settings and indicate a large potential for co-selection of resistance genes to a variety of antibiotic classes.