Differences and fingerprints of ESBL-producing E. coli from chicken faeces

Area of Science:

• Microbiology
• Genetics
• Biotechnology

Background:

• Escherichia coli (E. coli) is a significant reservoir for β-lactam resistance, with Extended Spectrum β-Lactamase (ESBL) producing strains posing a major public health threat due to their phylogenetic transmission.
• Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) is an FDA-approved technology for microbial identification, offering sensitive and specific applications in clinical diagnostics and food safety.

Purpose of the Study:

• To investigate β-lactamase genes in E. coli isolates.
• To explore the potential of protein expression profiles, analyzed via MALDI-TOF MS, to differentiate ESBL-producing E. coli.
• To examine the phenotypic protein differences in ESBL-producing bacteria.

Main Methods:

• Polymerase Chain Reaction (PCR) was employed to detect various β-lactamase genes, including bla_CTX-M, bla_CTX-M-1, bla_CTX-M-15, bla_SHV, bla_TEM, bla_OXA-10, bla_CIT, and bla_MOX.
• MALDI-TOF MS was utilized for phyloproteomic analysis to assess protein expression differences.
• Principle Component Analysis (PCA) was applied to analyze the proteomic data and identify variations among isolates.

Main Results:

• In Duzce, Türkiye, 28.6% of 122 Chicken Faeces E. coli (CFEC) isolates were identified as ESBL producers.
• The bla_CTX-M gene was the most frequently detected resistance gene (88.5%).
• Phyloproteomic analysis revealed distinct protein profiles between ESBL-producing and susceptible E. coli strains, highlighting isolate heterogeneity and homogeneity.

Conclusions:

• MALDI-TOF MS-based phyloproteomic analysis is a valuable tool for characterizing the phenotypic behavior of bacterial resistance, particularly in ESBL-producing E. coli.
• The study identified specific E. coli isolates with unique genetic and proteomic characteristics, contributing to a better understanding of resistance mechanisms.
• Further research is needed to address the limitations and fully elucidate the potential of these methods in combating antimicrobial resistance.