Abstract
The use of antibiotics in animal husbandry has long been associated with the appearance of antibiotic resistance and virulence factor determinants. Nonetheless, the number of cases of human infection involving resistant or virulent microorganisms that originate in farms is increasing. While many antibiotics have been banned as dietary supplements in some countries, other additives thought to be innocuous in terms of the development and spread of antibiotic resistance are used as growth promoters. In fact, several clay materials are routinely added to animal feed with the aim of improving growth and animal product quality. However, recent findings suggest that sepiolite, a clay additive, mediates the direct transfer of plasmids between different bacterial species. We therefore hypothesize that clays present in animal feed facilitate the horizontal transfer of resistance determinants in the digestive tract of farm animals.
Highlights
The exposure of bacteria to inhibitory concentrations of antibiotics results in the selection of resistant sub-populations
There is much concern surrounding the huge quantity of antimicrobial agents used as livestock growth promoters and the possibility that they select for resistance determinants, which can spread by different routes to human pathogens compromising antibiotic efficacy [5,6]
Antibiotic resistance genes conferring resistance to several antimicrobials have been used for the construction of some genetically modified plants which are used as animal feed [7]
Summary
The exposure of bacteria to inhibitory concentrations of antibiotics results in the selection of resistant sub-populations. A relationship between the presence of sand or clay minerals and bacterial genetic exchange has been reported, and the possibility that mineral-mediated DNA transfer between different bacterial species plays a role in the evolution of antibiotic resistance has received some attention [16]. Transformation of bacteria by foreign DNA in the presence of friction forces and clay materials is known as the Yoshida effect [17] This transformation relies on the ability of mineral nanofibers (or nanoneedles), such as those formed by sepiolite, to adsorb DNA and form a chestnut burr-shaped complex when a sliding friction force [18] or even vibrations [16] are applied. This effect was observed in many bacterial species (Table 1)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
