Estudi de la presència i transmissió de bacteris resistents a antibiòtics en aigües


Cambras Casas, Eloi


Currently, antibiotics are beginning to become less effective in the face of the increase in antibiotic-resistant bacteria. Genetic modifications that normally occur in the form of mobile genetic elements through horizontal gene transmission (HGT) (mainly conjugation) are responsible for the acquisition of this resistance. This work presents a review of the presence of antibiotic resistance in water and its forms of transmission. It has been described that HGT passes largely in resistance hot spots (hotspots) such as those influencing wastewater treatment plants (WWTPs) where the cell concentration is very high (large amount of fecal bacteria and bacteria previously selected) and there is presence of antibiotics in sub-inhibitory concentrations. The induction of the SOS response will be responsible for causing hypermutability and increasing horizontal gene transfer, generating new resistant determinants. WWTPs will carry out disinfection treatments that are not effective enough so that large amounts of bacteria and antibiotics will be released into the environment. Because environmental species have intrinsic mechanisms of resistance to antibiotics, it is likely that mixing with non-native species causes genetic exchange, aggravating the problem of resistance to antibiotics. Due to the misuse of antibiotics in the enormous biomass of cattle and the passage of these through the gastrointestinal tract (reservoir of resistance genes) will become another key point for the origin and spread of resistance. Likewise, administered antibiotics and ARBs may leach and contaminate other ecosystems. The presence of antibiotics generalized to the ecosystem will act as signaling for the bacteria to form biofilms, which provide greater phenotypic resistance. Surprisingly, resistance genes have been found to a greater or lesser extent in all the aquatic ecosystems studied. The fight against antibiotic resistance is difficult but not impossible since scientific studies have provided viable remedies such as the administration of antibiotics together with adjuvant or inhibitors of the SOS response.



Auset Vallejo, Maria


IQS SE -  Undergraduate Program in Biotechnology