The use of essential oils (EO) loaded with nanoparticles is the most promising alternative to increase food quality and safety. Interesting works describe the antimicrobial properties of EO for pathogen control in natural and processed foods for human health and animal production, also contributing to sustainability. Their association with different nanosystems allows novel developments in the micronutrition, health promotion, and pathogen control fields, preventing the aggravation of bacterial microevolution and combating antibiotic resistance. Benefits to the environment are also provided, as they are biodegradable and biocompatible. However, such compounds have some physicochemical properties that prevent commercial use. This review focuses on recent developments in antimicrobial EO-based nanoparticles and their application in different food matrices.

Salmonella spp. continues to figure prominently in world epidemiological registries as one of the leading causes of bacterial foodborne disease. We characterised 43 Brazilian lineages of Salmonella Typhimurium (ST) strains, characterized drug resistance patterns, tested copper (II) complex as control options, and proposed effective antimicrobial measures. The minimum inhibitory concentration was evaluated for seven antimicrobials, isolated and combined with the copper (II) complex [Cu(4-FH)(phen)(ClO₄)₂] (4-FH = 4-fluorophenoxyacetic acid hydrazide and phen = 1,10-phenanthroline), known as DRI-12, in planktonic and sessile ST. In parallel, 42 resistance genes were screened (PCR/microarray). All strains were multidrug resistant (MDR). Resistance to carbapenems and polymyxins (86 and 88%, respectively) have drawn attention to the emergence of the problem in Brazil, and resistance is observed also to CIP and CFT (42 and 67%, respectively), the drugs of choice in treatment. Resistance to beta-lactams was associated with the genes bla_TEM/bla_CTX-M in 39% of the strains. Lower concentrations of DRI-12 (62.7 mg/L, or 100 μM) controlled planktonic and sessile ST in relation to AMP/SUL/TET and AMP/SUL/TET/COL, respectively. The synergistic effect provided by DRI-12 was significant for COL/CFT and COL/AMP in planktonic and sessile ST, respectively, and represents promising alternatives for the control of MDR ST.

This study evaluated the feasibility and the production of transcripts of sodB, p19, ciaB and dnaJ genes in strains of Campylobacter jejuni ATCC 33291, NCTC 11351, and 2383 IAL stored in whole UHT milk and or neopepton + 12% glycerol, submitted or not to pre-treatments at 4°C or 10°C for 30 minutes. The analyzes were performed immediately after freezing in liquid nitrogen (day 0) and after maintenance for 30, 60, and 90 days at -20ºC. The viability was evaluated by the traditional culture method and the production of transcripts by the RT-PCR technique. The quantification was only possible on the first day of analysis (day 0) and presented a mean of 3.0 x 107 CFU, and in the other periods of storage the strains presented confluent growth, not allowing their enumeration. The results indicated that whole UHT milk was more adequate for cryopreservation than the use of neopepton + 12% glycerol. The use of pre-treatments combined with the use of UHT milk as a cryoprotective medium stabilized the cells in order to transcribe the ciaB, dnaJ, sodBand p19 genes in the strains maintained under -20 ° for 30 to 60 days, indicating that they are more suitable methods for the maintenance of strains in the laboratory.