Aeromonas spp.: model for monitoring the impact of antibiotic compounds in water environments
Presentano: Federica Mauri, Alessandro Carnelli e Antonella Demarta
Antibiotic resistant bacteria and antibiotic resistance genes are causing increasing problems especially in clinical settings. Nowadays they are considered important environmental contaminants but little is known yet about their fate in the environment or about how they affect the natural microbial populations. In the environment, especially in water, antibiotic determinants may become part of the environmental gene pool, may spread horizontally, and may move back to humans and animals via contaminated food and drinking water.
Bacteria of the genus Aeromonas are ubiquitous in aquatic environments. They can therefore be used as a model of hydric microorganisms exposed to the residual antibiotic compounds and to the aquatic resistome. On the other hand, fecal coliforms, a non taxonomic group that includes genera of bacteria that originate mainly from human and animal feces, represent an allochthonous population of the water environment; they are primarily exposed to antibiotics used and misused in clinical and veterinarian settings.
We at first examined the presence, the distribution and the transferability of the more important resistance determinants. i.e. transposons, integrons, and plasmids, in strains isolated from aquatic environments submitted to diverse levels of antibiotic contamination. In a second time, we investigated the role of Aeromonas spp. in the spread of resistances studying their conjugation, transformation and transduction abilities.
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