Impact of colistin and colistin-loaded on alginate nanoparticles on pigs infected with a colistin-resistant enterotoxigenic Escherichia coli strain

Djamel Drider (1) , Rabah Boukherroub (2, 3) , Laetitia Le Devendec (4) , Yanath Belguesmia (1) , Noura Hazime (5, 2) , Gwenaelle Mourand (4) , Frédéric Paboeuf (4) , Isabelle Kempf (4)

1 BioEcoAgro - Equipe 8 - Food and Digestive Microbial Ecosystems: Interactions - Dynamics - Application(s)
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 NBI - IEMN - NanoBioInterfaces - IEMN
4 Laboratoire de Ploufragan-Plouzané-Niort [ANSES]
5 BioEcoAgro - UMR transfrontalière INRAE 1158

Colistin is frequently used for the control of post-weaning diarrhoea in pigs. Colistin resistance caused by plasmidic genes is a public health issue. We evaluated, in experimental animal facilities, whether free colistin or colistin-loaded on alginate nanoparticles (colistin/Alg NPs) could select a colistin-resistant Enterotoxigenic Escherichia coli. The Alg NPs were produced by a simple top-down approach through ball milling of sodium alginate polymer precursor, and colistin loading was achieved through physical adsorption. Colistin loading on Alg NPs was confirmed using various tools such Fourier transform infrared spectroscopy and dynamic light scattering measurements. Thirty-four piglets were orally inoculated or not with a mcr-1-positive, rifampicin-resistant enterotoxigenic E. coli strain, and the inoculated pigs were either treated or not during five days with commercial colistin (100,000 IU/kg) or colistin/Alg NPs (40,415 IU/kg). Clinical signs were recorded. Fecal and post-mortem samples were analyzed by culture. The result clearly indicated that colistin/Alg NPs had a slightly better therapeutic effect. Both treatments led to a transitory decrease of the total E. coli fecal population with a majority of colistin-resistant E. coli isolates during treatment, but the dominant E. coli population was found susceptible at the end of the trial. Further studies are needed to evaluate, in diverse experimental or field conditions, the therapeutic efficacy of colistin/Alg NPs for post-weaning diarrhoea.

Mots clés: Post-weaning diarrhea; Pig Colistin; Enterotoxigenic; Escherichia coli; Alginate; Nanoparticles

Domaines: Chimie; Sciences de l'ingénieur [physics]

Djamel Drider, Rabah Boukherroub, Laetitia Le Devendec, Yanath Belguesmia, Noura Hazime, et al.. Impact of colistin and colistin-loaded on alginate nanoparticles on pigs infected with a colistin-resistant enterotoxigenic Escherichia coli strain. Veterinary Microbiology, 2022, 266, pp.109359. ⟨10.1016/j.vetmic.2022.109359⟩. ⟨hal-03561670⟩