Antimicrobial resistance in environment and wastewaters of a swine slaughterhouse – tracking ESKAPE bacteria and ESBL-/carbapenemase-producing Escherichia coli
4 affiliations
- 1Department of Food and Drug Sciences, University of Parma
- 2“B. Umbertini” Experimental Zooprophylactic Institute of Lombardy and Emilia-Romagna
- 3Department of Veterinary Medicine, “G. Tiecco” Postgraduate Specialization School of Inspection of Food of Animal Origin, University of Teramo
- 4AST Marche, Area Vasta 5, I.A.O.A. Veterinary Service
Abstract
Introduction: This study investigated the occurrence, antimicrobial resistance (AMR) profiles, and genomic features of selected ESKAPE bacteria and ESBL-/carbapenemase-producing Escherichia coli isolated from wastewater and floor swabs in a swine slaughterhouse in Central Italy.
Methods: By integrating microbiological and genomic analyses across different operational phases, the study observed persistence and dissemination of antimicrobial resistant bacteria (ARB) within the abattoir environment.
Results: E. coli was the most prevalent species (39.6%) across all matrices, confirming its role as an indicator of fecal and environmental contamination. Despite cleaning and depuration, few ARB and antimicrobial resistance genes (ARGs) persisted, particularly in wastewater, reflecting the partial efficacy of conventional sanitation and treatment measures. The antimicrobial susceptibility tests revealed high resistance against ampicillin (47.2%), tetracycline (41.2%), and trimethoprim (34.0%), with multidrug resistant isolates occurring in nearly one-third of samples. Whole-genome sequencing identified the resistome, e.g., bla TEM , bla CTX-M , and bla OXA-48 genes. The detection of bla NDM in treated wastewater underscores the potential for environmental dissemination of carbapenemase producers. Phylogenetic analyses revealed clonal persistence of OXA- and ESBL-producing E. coli and Acinetobacter baumannii across samples, while livestock-associated MRSA ST398 indicated localized contamination events.
Discussion: These findings demonstrate that slaughterhouse ecosystems can function as active reservoirs and transmission nodes for AMR.
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BibTeX
@article{manfreda2026antimicrobial,
title = {{Antimicrobial resistance in environment and wastewaters of a swine slaughterhouse – tracking ESKAPE bacteria and ESBL-/carbapenemase-producing Escherichia coli}},
author = {Chiara Manfreda and Flavia Guarneri and Gianluigi Ferri and Chiara Di Vittori and Alberto Olivastri and Maria Antonietta Piccioni and Adriana Ianieri and Giovanni Loris Alborali and Alberto Vergara},
journal = {Frontiers in Microbiology},
year = {2026},
month = oct,
doi = {10.3389/fmicb.2026.1957049},
url = {https://www.frontiersin.org/articles/10.3389/fmicb.2026.1957049/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Antimicrobial resistance in environment and wastewaters of a swine slaughterhouse – tracking ESKAPE bacteria and ESBL-/carbapenemase-producing Escherichia coli
AU - Chiara Manfreda
AU - Flavia Guarneri
AU - Gianluigi Ferri
AU - Chiara Di Vittori
AU - Alberto Olivastri
AU - Maria Antonietta Piccioni
AU - Adriana Ianieri
AU - Giovanni Loris Alborali
AU - Alberto Vergara
PY - 2026
DA - 2026/10/28
JO - Frontiers in Microbiology
DO - 10.3389/fmicb.2026.1957049
UR - https://www.frontiersin.org/articles/10.3389/fmicb.2026.1957049/full
AB - Introduction: This study investigated the occurrence, antimicrobial resistance (AMR) profiles, and genomic features of selected ESKAPE bacteria and ESBL-/carbapenemase-producing Escherichia coli isolated from wastewater and floor swabs in a swine slaughterhouse in Central Italy. Methods: By integrating microbiological and genomic analyses across different operational phases, the study observed persistence and dissemination of antimicrobial resistant bacteria (ARB) within the abattoir environment. Results: E. coli was the most prevalent species (39.6%) across all matrices, confirming its role as an indicator of fecal and environmental contamination. Despite cleaning and depuration, few ARB and antimicrobial resistance genes (ARGs) persisted, particularly in wastewater, reflecting the partial efficacy of conventional sanitation and treatment measures. The antimicrobial susceptibility tests revealed high resistance against ampicillin (47.2%), tetracycline (41.2%), and trimethoprim (34.0%), with multidrug resistant isolates occurring in nearly one-third of samples. Whole-genome sequencing identified the resistome, e.g., bla TEM , bla CTX-M , and bla OXA-48 genes. The detection of bla NDM in treated wastewater underscores the potential for environmental dissemination of carbapenemase producers. Phylogenetic analyses revealed clonal persistence of OXA- and ESBL-producing E. coli and Acinetobacter baumannii across samples, while livestock-associated MRSA ST398 indicated localized contamination events. Discussion: These findings demonstrate that slaughterhouse ecosystems can function as active reservoirs and transmission nodes for AMR.
SN - 1664-302X
ER -