Background/Objectives: This study aimed to develop gel nanoemulsions (NEs) of Brazilian essential oils (EOs) from Eugenia uniflora and Psidium guajava, as well as to perform chemical characterization and investigate the antimicrobial activity of the EOs and NEs. Results/Conclusions: The main chemical compounds of E. uniflora EO were curzerene (34.80%) and germacrene B (11.92%), while those of P. guajava EO were β-caryophyllene (25.92%), β-selinene (22.64%), and γ-selinene (19.13%). The NEs of E. uniflora and P. guajava had droplet sizes of 105.30 and 99.50 nm and polydispersity index (PDI) values of 0.32 and 0.43, respectively. The NEs remained stable for 30 days of storage at 25 °C, with droplet sizes of 104.7 and 103.8 nm, PDI values below 0.50, and no phase separation. The NE of E. uniflora exhibited inhibition zones ranging from 8.41 to 15.13 mm against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. Additionally, the NE of E. uniflora showed the largest inhibition zones against Candida albicans (20.97 mm) and Candida krusei (15.20 mm), along with low minimum inhibitory concentration (MIC) values (0.54–1.22 mg/mL) and minimal bactericidal concentration (MBC) values (4.84–11.02 mg/mL) against these pathogenic yeasts. The NE of P. guajava demonstrated low MIC (1.26 mg/mL) and MBC (11.35 mg/mL) values for C. krusei. The time–growth inhibition assay also suggests the effectiveness of the NE against the tested pathogens S. aureus and E. coli, highlighting its potential as a novel alternative therapeutic agent.

Background/Objectives: This study characterized the phenotypic and genotypic profiles of antimicrobial resistance in 104 Escherichia coli isolates obtained from 22 samples of artisanal Minas Frescal cheese from the Federal District, Brazil. Methods: The antimicrobial susceptibility of E. coli isolates was assessed using the disk diffusion method and antimicrobial resistance genes were detected using polymerase chain reaction methods with specific primers. Results: The highest rates of phenotypic antimicrobial resistance were observed for sulfonamides (85.58%, 89/104) and tetracyclines (38.46%, 40/104). In the genotypic profiles, most E. coli isolates carried the sulfonamide resistance genes sul1/sul2 (62.50%, 65/104), tetracycline resistance genes tetA/tetB (65.38%, 68/104), and β-lactam resistance genes blaCTX-M/blaTEM/blaSHV (55.77%, 58/104). Most E. coli strains that presented sulfonamide resistance genes carried the sul1 gene (49.04%, 51/104) and were phenotypically sulfonamide-resistant strains (59.61%, 62/104). Regarding the E. coli strains that carried tetracycline resistance genes, the majority harbored both tetA and tetB genes (34.61%, 36/104), with 35.56% (37/104) being phenotypically resistant and 29.80% (31/104) being phenotypically susceptible. For E. coli strains that presented β-lactam resistance genes, the most frequently detected gene was blaCTX-M (21.15%, 22/104) and, notably, most E. coli strains (43.26%, 45/104) were phenotypically susceptible. The cat1 and clmA genes (associated with phenicol resistance) were detected in 22.12% of the E. coli isolates (23/104), with only two strains (1.92%) being phenotypically resistant to chloramphenicol. Conclusion: The high prevalence of E. coli carrying antimicrobial resistance genes in artisanal cheese raises public health concerns regarding the dissemination of potentially pathogenic antimicrobial-resistant microorganisms through the food chain.

This study evaluated the antimicrobial activity of Chrysopogon zizanioides (vetiver) and Schinus terebinthifolius (aroeira) essential oils (EO) and their nanoemulsions, along with chemical characterization of the EO. The major compounds in C. zizanioides EO were the sesquiterpenes vetivenic acid (22.95%), α‐vetivone (7.50%), khusimol (7.42%), and β‐vetivone (5.63%), while S. terebinthifolius EO was rich in the monoterpenes α‐phellandrene (35.96%), α‐pinene (15.41%), limonene (14.39%), and δ‐3‐carene (10.70%). Nanoemulsion droplet sizes were 304.7 nm for vetiver and 105.7 nm for aroeira, with PDI values of 0.32 and 0.20, and zeta potentials of −0.82 and 0.33 mV, respectively. Vetiver nanoemulsion enhanced antimicrobial activity against Bacillus cereus , Klebsiella pneumoniae , and Salmonella enterica , while aroeira nanoemulsion increased activity against B. cereus , K. pneumoniae , and Escherichia coli . These findings demonstrate that nanoemulsification is an effective strategy to potentiate the antimicrobial properties of vetiver and aroeira EO, improving their efficacy against both Gram‐positive and Gram‐negative bacteria.

Introduction: Essential oils (EO), rich in bioactive compounds, possess diverse biological properties

Introduction: Lactobacillus gasseri and Lactobacillus crispatus are lactic acid bacteria from the vaginal and intestinal microbiota that produce bioactive metabolites with antimicrobial potential

Introduction: Gram-negative bacteria present a major therapeutic challenge due to their phospholipid barrier, which restricts drug penetration