Work

Prevalence of the cfr gene and co-dissemination with the fosD gene in swine-derived Staphylococcus aureus

Year: 2025

Type: article

Abstract: • MSSA-ST9-t4358 strain co-harboring cfr and fosD demonstrated that both genes were located on a plasmid also carrying fexA and aadD . • Seven cfr -positive S. aureus strains were identified from 302 swine-derived S. aureus . • The spread of cfr in S. aureus strains was closely associated with insertion sequence IS 256 and transposon Tn558 variant, respectively. • Cfr-positive S. aureus isolateswere multi-drug resistant and carried several resistance genes. Animal-derived Staphylococcus aureus frequently exhibits multidrug resistance (MDR), with complex and diverse resistance mechanisms that have raised significant public health concerns. The objective of this study was to determine the prevalence of S. aureus in swine farms and evaluate its antimicrobial resistance and distribution of oxazolidinone resistance genes. The swine samples were collected on 17 swine farms from four provinces in China. All S. aureus isolates were screened for cfr, optrA , and poxtA . Whole-genome sequencing (WGS) of cfr -positive strains revealed their molecular characteristics. All cfr -positive isolates were subjected to antimicrobial susceptibility testing. 302 swine-derived S. aureus were collected from 4973 samples. Seven cfr -positive S. aureus strains including four ST1-t4792 MSSA, two ST9-t4358 MSSA and one ST398-t034 MRSA were identified by whole-genome sequencing. Antimicrobial susceptibility testing against 23 agents from 12 classes revealed that all cfr -positive strains were resistant to penicillin, ampicillin, erythromycin, tetracycline, doxycycline, clindamycin, florfenicol, tiamulin, and valnemulin. Six MSSA strains additionally exhibited resistance to gentamicin, kanamycin, and ciprofloxacin, while three strains showed resistance to tilmicosin, ciprofloxacin, and trimethoprim-sulfamethoxazole. Third-generation sequencing of a strain co-harboring cfr and fosD demonstrated that both genes were located on a plasmid also carrying fexA and aadD . This study revealed the presence of the cfr gene across diverse MLST types of Staphylococcus aureus and highlighted the co-dissemination of cfr with fosD and other resistance genes via plasmids in S. aureus . Based on One Health principles and risk of multidrug resistance spread, continuous surveillance of animal-derived S. aureus was urgently needed.

Source: Journal of Global Antimicrobial Resistance

DOI: 10.1016/j.jgar.2025.11.009

Authors: Wei Li, Wenguang Xiong, Junzhuo Guo, Na Sun, Zhenling Zeng

Institutions: Jilin Agricultural Science and Technology University, South China Agricultural University

Language: English

Topic: Antimicrobial Resistance in Staphylococcus

Subfield: Infectious Diseases

Field: Medicine

Domain: Health Sciences

SDGs: Good health and well-being, Zero hunger

Open Access status: gold

Estimated APC paid: $1,890