Tannins and Antimicrobials Resistance in Clostridium perfringens

DOMINGUEZ, J E; REDONDO, L M; RABINOVITZ, B C; REDONDO, E A; DIAZ-CARRASCO, JM; FERNANDEZ MIYAKAWA, ME

Friburgo

Congreso; 9th International Conference on the Molecular Biology and Pathogenesis of the Clostridia / CLOSTPATH 2015; 2015

Tannins added tothe diet are being used to improve nutrition and health in farm animals as analternative to antibiotic growth promoters (AGPs) and to control entericclostridial diseases. The use of AGPs is being discouraged due to the developmentof antimicrobial resistance. Tannins as feed additives could be a promisingalternative to control the disease. However, the capacity of Clostridium perfringens (CP) to developresistance under the selective pressure of tannins is unknown. The purpose ofthis study was to determine if CP possesses the ability to develop resistance againsttannins in comparison with antimicrobial agents. Thesusceptibility to tannins and AGPs was evaluated by the determination ofMinimal Inhibitory Concentration (MICs) in poultry and cattle isolates. Withthis, it is challenged the concept that development of tannin resistance isdifficult. Transmission electron microscopy was employed to examine the wallstructure of in vitro tannin-adaptedisolates of CP. Susceptible strains with the lowest MICs were chosen to determineif the exposure of vegetative cells to sub-inhibitory concentrations of AGPs ortannins could induce the development of resistance.Isolates show a decrease in sensitivity to antimicrobialswhich was highly correlated with an increased resistance to AGPs, but this wasnot observed with tannins. TEM showed that there was an alteration of thecell wall when bacteria were exposed to tannins. Theseresults suggest that the antibacterial activity of tannins against CP could beeffective during long periods of time since de development of resistance totannins would be difficult.