Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli

Abstract

Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-␤-lactamase-producing E. coli. Groups of pigs were orally inoculated with strain E. coli M63 carrying the bla CTX-M-1 gene (n ϭ 84) or used as a control (n ϭ 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and bla CTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log 10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut.

Interplay between bacterial clone and plasmid in the spread of antibiotic resistance genes in the gut: lessons from a temporal study in veal calves

“…5). Spread of bla CTX-M -carrying plasmid among commensal E. coli populations had already been observed in orally inoculated piglets with an E. coli strain carrying bla CTX-M-1 gene (61). It has been shown both in vitro and in vivo in mice that conjugation frequencies vary across plasmid, donor, and recipient combinations (85).…”

“…Loss of bla CTX-M carrying plasmid may have happened during our study, but as we focused only on E. coli clones displaying a phenotype of ESBL production, we cannot estimate the magnitude of such loss rate. Studies showed that spontaneous loss happens rarely in vivo, even when ESBL-producing strains compete with plasmid-free strains, as shown in pigs, rabbits and lambs (60)(61)(62)(63). A modulation of the cost by a selective switch off of horizontally acquired gene expression (64,65) could also explain why no association was found between genes and the ability for a clone to colonize many calves nor to persist in farms.…”

Impact of Escherichia coli probiotic strains ED1a and Nissle 1917 on the excretion and gut carriage of extended-spectrum beta-lactamase-producing E. coli in pigs

“…They were identified with an E. coli -specific PCR ( Furet et al., 2009 ); the presence of the bla CTX − M-1 gene was screened for using PCR ( Woodford, Fagan & Ellington, 2006 ). Moreover, the isolates obtained from pigs were also tested by PCRs specific to the E. coli ED1a or EcN strains ( Mourand et al., 2017 ). Finally, for all faecal samples collected on day 49 and rectum samples on day 58, a cell lysate was prepared from all the pooled colonies obtained on non-supplemented MC plates, and for manure samples, a suspension was prepared from all the pooled colonies of the MC—CTX plates for PCR analysis, as described below.…”

“…Each DNA extract was quantified using the NanoDrop 2000 spectrophotometer (Thermo Scientific) then adjusted to a concentration of 10 ng/µL, before storage at −20 °C. E. coli, E. coli ED1a and E. coli EcN were quantified in faeces, PM and manure samples from piglets according to Mourand et al. (2017) .…”

“…In France, an efficient cephalosporin stewardship programme deployed in swine production units has helped reduce cephalosporin use and contain resistance ( Verliat et al., 2021 ), but strategies to reduce the number of ESCR Enterobacterales in pig faeces are still needed. In a previous study ( Mourand et al., 2017 ), we tested the possibility of competition between ESCR Enterobacterales and E. coli probiotics ( Mourand et al., 2017 ) . Thus, the possibility of preventing the colonization of weaned specific-pathogen-free (SPF) piglets via an oral inoculation of ESCR E. coli was explored by comparing the ESCR E. coli titres of piglets born to E. coli probiotic (ED1a)-treated sows and given the probiotic from birth to weaning, with non-treated piglets born to non-treated sows.…”