Antibiotic resistance (ABR) has direct and indirect repercussions on public health and threatens to decrease the therapeutic effect of antibiotic treatments and lead to more infection-related deaths. There are several mechanisms by which ABR can be transferred from one microorganism to another. The risk of transfer is often related to environmental factors. The food supply chain offers conditions where ABR gene transfer can occur by multiple pathways, which generates concerns regarding food safety. This work reviews mechanisms involved in ABR gene transfer, potential transmission routes in the food supply chain, the prevalence of antibiotic residues in food and ABR organisms in processing lines and final products, and implications for public health. Finally, the paper will elaborate on the application of antimicrobial peptides as new alternatives to antibiotics that might countermeasure ABR and is compatible with current food trends.

Background: Agro-industrial waste from tropical environments could be an important source of lactic acid bacteria (LAB) with probiotic potential. Methods: Twelve LAB isolates were isolated from pineapple silages. The species identification was carried out considering 16S rRNA and pheS genes. Experiments to evaluate the probiotic potential of the isolates included survival under simulated gastrointestinal environment, in vitro antagonistic activity (against Salmonella spp. and Listeria monocytogenes), auto-aggregation assays, antibiotic susceptibility, presence of plasmids, adhesiveness to epithelial cells, and antagonistic activity against Salmonella in HeLa cells. Results: Lacticaseibacillus paracasei, Lentilactobacillus parafarraginis, Limosilactobacillus fermentum, and Weissella ghanensis were identified. Survival of one of the isolates was 90% or higher after exposure to acidic conditions (pH: 2), six isolates showed at least 61% survival after exposure to bile salts. The three most promising isolates, based on survivability tests, showed a strong antagonistic effect against Salmonella. However, only L. paracasei_6714 showed a strong Listeria inhibition pattern; this isolate showed a good auto-aggregation ability, was resistant to some of the tested antibiotics but was not found to harbor plasmids; it also showed a high capacity for adhesion to epithelial cells and prevented the invasion of Salmonella in HeLa cells. After further in vivo evaluations, L. paracasei_6714 may be considered a probiotic candidate for food industry applications and may have promising performance in acidic products due to its origin.

Mycotoxins pose significant threats to food security and human health, necessitating innovative approaches for fungal control. This study investigated the antifungal and antimycotoxigenic potential of lactic acid bacteria (LAB) isolated from agro‐industrial byproducts against the toxigenic fungi Aspergillus flavus and Fusarium verticillioides . Then, 14 LAB isolates were phylogenetically characterized, revealing diverse species including Lactiplantibacillus pentosus , Lactiplantibacillus plantarum, Lacticaseibacillus paracasei , and Leuconostoc pseudomesenteroides . Their antagonistic activity was first screened using an overlay‐streak assay, which evaluated the combined effects of competition, pH reduction, and metabolite production on mycelial growth. Subsequently, the effect of their neutralized cell‐free supernatants (CFS)—containing possible pH‐stable antimicrobial compounds—was tested on fungal proliferation. The results revealed a distinct, mode‐of‐action‐dependent efficacy. In the direct coculturing assay, stronger inhibition was observed against F. verticillioides , with six L. pentosus strains achieving nearly 100% growth suppression. In contrast, CFS treatments exhibited a more pronounced inhibitory effect on A. flavus germination and growth rate, with L. plantarum 71(6)‐2F showing activity comparable to a positive control. This shift in efficacy is explicitly attributed to the different mechanisms assessed in each assay: the overlay method reflects broad‐spectrum inhibition driven largely by competition and acidification, to which F. verticillioides appears highly sensitive. The CFS assay, however, highlights the impact of specific, pH‐neutral antimicrobial metabolites. Furthermore, several CFS extracts significantly reduced mycotoxin biosynthesis, suggesting these LAB metabolites can disrupt critical fungal physiological pathways. These findings underscore the potential of LAB from agro‐industrial byproducts as a source of natural antifungal and antimycotoxigenic compounds.

The aim of this research was to isolate and identify lactic acid bacteria (LAB) from pineapple waste. The survival in refrigerated pineapple juices, of a selected isolate with potential probiotic properties, was also studied. The 16S rRNA and pheS partial genes were used to identify LAB, multilocus sequence typing (MLST) genes were used in order to separate strains grouping with Lactobacillus casei and L. paracasei phylogenetically. Tests for survival at pH 2.0, resistance to lysozyme and tolerance to bile salts were used to screen the strains for potential probiotic properties. A L. fermentum isolate was used for the survival study. Three types of pineapple juice made from pulp, a blend of pulp and peel (80:20), and peel extract were inoculated to approximately 10 ⁶ CFU/mL with L. fermentum and stored at 4 °C for up to six weeks. The physicochemical composition of juices, including concentration of fermentable sugars and organic acids, total solids content, soluble solids content, titratable acidity and pH, was determined during the survival study. Two genera and five species were identified. Pineapple juices supported the survival of L. fermentum during refrigerated storage but the population of the bacteria decreased over time regardless of the juice type. Juice made from pulp was a more suitable vehicle for the survival of the selected LAB. Some of the juice physicochemical properties, including sugars and organic acids content, pH and titratable acidity, varied significantly (P<0.05) during storage. Further sensory studies are necessary to evaluate consumer acceptance of juices containing the selected isolate. IMPORTANCE: Lactic acid bacteria (LAB), isolated from pineapple waste, were phylogenetically analyzed and characterized in regards to their tolerance to pH 2.0, lysozyme and bile salts; showing their potential as probiotic strains, if health benefits associated to their ingestion are eventually confirmed. Moreover, pineapple juice supported the survival of Lactobacillus fermentum , isolated from the same food matrix, during refrigerated storage at 4 °C. Among the three pineapple juices tested (pulp, pulp + peel and peel), L. fermentum survived better in juice made from pulp. However, significant variations were observed overtime in some of the physicochemical properties of the juices including sugars and organic acids content, pH and total titratable acidity.