# Molecular characterization and susceptibility of foodborne Escherichia coli to conventional antibiotics and natural extracts of Solanum palinacanthum and Siparuna guianensis

## TL;DR

This study found that many E. coli strains from food are resistant to multiple antibiotics and not affected by natural plant extracts, raising concerns for food safety.

## Contribution

The study reports high multidrug resistance in foodborne E. coli and lack of susceptibility to two natural plant extracts.

## Key findings

- 55.3% of E. coli isolates were multidrug-resistant.
- Most E. coli strains belonged to phylogenetic groups B1, A, or C.
- No susceptibility was observed to the tested natural plant extracts.

## Abstract

The present study aimed to evaluate the antimicrobial susceptibility profile and molecular characteristics of Escherichia coli isolated from various foods, including ground beef, pork, Minas fresh cheese, lettuce, and chicken. A total of 150 E. coli strains were recovered and tested against conventional antimicrobials and crude extracts of Solanum palinacanthum and Siparuna guianensis. Susceptibility testing was conducted using disk diffusion and broth microdilution methods. Additionally, phylogenetic characterization and pathotype identification were performed via polymerase chain reaction (PCR). Results indicated that all E. coli isolates were resistant to at least two antimicrobial classes, with 55.3% (n = 83) classified as multidrug-resistant (MDR). Most strains belonged to phylogenetic groups B1, A, or C. Regarding the natural extracts, the isolates were not sensitive to either S. palinacanthum or S. guianensis. In conclusion, the high prevalence of MDR E. coli across diverse food groups represents a critical concern for food safety and public health. Furthermore, the lack of susceptibility to the tested plant extracts highlights the challenge of identifying alternative natural antimicrobials, underscoring the urgent need for stricter control measures to mitigate the spread of resistant foodborne pathogens.

The online version contains supplementary material available at 10.1007/s42770-026-01898-9.