Previous Article in Journal
Evaluation of Clean-Label Additives to Inhibit Molds and Extend the Shelf Life of Preservative-Free Bread
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Microbiology Research
Volume 16
Issue 8
10.3390/microbiolres16080180
microbiolres-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Article

Occurrence and Transfer by Conjugation of Linezolid- Resistance Among Non-Enterococcus faecalis and Enterococcus faecium in Intensive Pig Farms

by
Giorgia Piccioni
1,
Andrea Di Cesare
2,3,
Raffaella Sabatino
2,3,
Gianluca Corno
2,3,
Gianmarco Mangiaterra
1,*,
Daniela Marchis
4 and
Barbara Citterio
1
1
Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino, Italy
2
Water Research Institute (IRSA)— Molecular Ecology Group (MEG), National Research Council of Italy (CNR), Largo Tonolli 50, 28922 Verbania, Italy
3
National Biodiversity Future Center (NBFC), Piazza Marina 61, 90133 Palermo, Italy
4
Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d’Aosta, 10154 Torino, Italy
*
Author to whom correspondence should be addressed.
Microbiol. Res. 2025, 16(8), 180; https://doi.org/10.3390/microbiolres16080180 (registering DOI)
Submission received: 23 May 2025 / Revised: 30 July 2025 / Accepted: 31 July 2025 / Published: 2 August 2025
(This article belongs to the Special Issue Zoonotic Bacteria: Infection, Pathogenesis and Drugs—Second Edition)
Versions Notes

Abstract

Enterococcus spp. are opportunistic and nosocomial pathogens. Intensive pig farms have been recently described as important hotspots for antibiotic resistance and reservoirs of potentially pathogenic enterococci, including other species than the most known E. faecalis and E. faecium. Here, we identified Linezolid-resistant non-E. faecalis and E. faecium (NFF) Enterococcus strains isolated from different production stages (suckling piglets, weaning pigs, and fatteners) across six intensive pig farms. The transferability of the linezolid-resistance determinants was assessed by bacterial conjugation and strains were also characterized for biofilm production, hemolytic and gelatinase activity. Among 64 identified NFF Enterococcus strains, 27 were resistant to at least three different antibiotic classes and 8/27 specifically to Linezolid. E. gallinarum and E. casseliflavus both transferred their Linezolid resistance determinants to the main pathogenic species E. faecium. Remarkably, this is the first report of the optrA gene transfer from E. casseliflavus to E. faecium by conjugation, which can greatly contribute to the spread of antibiotic resistance genes among pathogenic enterococcal species. The “weaning pigs” stage exhibited a significantly higher number of antibiotic-resistant enterococci than the “fatteners”. These findings highlight the importance of monitoring pig farms as hotspots for the spread of antibiotic-resistant enterococci, especially in the early stages of production. Furthermore, they underscore the significant role of NFF Enterococcus species as carriers of antibiotic resistance genes, even to last-resort antibiotics, which may be transferable to the major enterococcal species.
Keywords: NFF Enterococcus species; linezolid resistance; resistance genes; conjugation; intensive pig farms NFF Enterococcus species; linezolid resistance; resistance genes; conjugation; intensive pig farms

Share and Cite

MDPI and ACS Style

Piccioni, G.; Di Cesare, A.; Sabatino, R.; Corno, G.; Mangiaterra, G.; Marchis, D.; Citterio, B. Occurrence and Transfer by Conjugation of Linezolid- Resistance Among Non-Enterococcus faecalis and Enterococcus faecium in Intensive Pig Farms. Microbiol. Res. 2025, 16, 180. https://doi.org/10.3390/microbiolres16080180

AMA Style

Piccioni G, Di Cesare A, Sabatino R, Corno G, Mangiaterra G, Marchis D, Citterio B. Occurrence and Transfer by Conjugation of Linezolid- Resistance Among Non-Enterococcus faecalis and Enterococcus faecium in Intensive Pig Farms. Microbiology Research. 2025; 16(8):180. https://doi.org/10.3390/microbiolres16080180

Chicago/Turabian Style

Piccioni, Giorgia, Andrea Di Cesare, Raffaella Sabatino, Gianluca Corno, Gianmarco Mangiaterra, Daniela Marchis, and Barbara Citterio. 2025. "Occurrence and Transfer by Conjugation of Linezolid- Resistance Among Non-Enterococcus faecalis and Enterococcus faecium in Intensive Pig Farms" Microbiology Research 16, no. 8: 180. https://doi.org/10.3390/microbiolres16080180

APA Style

Piccioni, G., Di Cesare, A., Sabatino, R., Corno, G., Mangiaterra, G., Marchis, D., & Citterio, B. (2025). Occurrence and Transfer by Conjugation of Linezolid- Resistance Among Non-Enterococcus faecalis and Enterococcus faecium in Intensive Pig Farms. Microbiology Research, 16(8), 180. https://doi.org/10.3390/microbiolres16080180

Article Metrics

Back to TopTop