Antibiotic-Resistant Produces HS from Supplements for Animal Farming.

Sulphate-reducing bacteria, primarily , are responsible for the active generation of HS in swine production waste. The model species for sulphate reduction studies, strain L2, was previously isolated from swine manure characterized by high rates of dissimilatory sulphate reduction. The source of electron acceptors in low-sulphate swine waste for the high rate of HS formation remains uncertain. Here, we demonstrate the ability of the L2 strain to use common animal farming supplements including L-lysine-sulphate, gypsum and gypsum plasterboards as electron acceptors for HS production. Genome sequencing of strain L2 revealed the presence of two megaplasmids and predicted resistance to various antimicrobials and mercury, which was confirmed in physiological experiments. Most of antibiotic resistance genes (ARG) are carried by two class 1 integrons located on the chromosome and on the plasmid pDsulf-L2-2. These ARGs, predicted to confer resistance to beta-lactams, aminoglycosides, lincosamides, sulphonamides, chloramphenicol and tetracycline, were probably laterally acquired from various and . Resistance to mercury is likely enabled by two operons also located on the chromosome and on pDsulf-L2-2 and acquired via horizontal gene transfer. The second megaplasmid, pDsulf-L2-1, encoded nitrogenase, catalase and type III secretion system suggesting close contact of the strain with intestinal cells in the swine gut. The location of ARGs on mobile elements allows us to consider strain L2 as a possible vector transferring antimicrobials resistance determinants between the gut microbiote and microbial communities in environmental biotopes.