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.

Salmonella represents one of the most common foodborne pathogens, frequently associated with the contamination of poultry products, constituting a prominent worldwide public health concern. This study determined the prevalence and antimicrobial resistance of Salmonella spp. in chilled chicken meat (115 samples) commercialized at retail in the Federal District, Brazil. Microbiological tests were performed to screen for Salmonella spp. in the chicken meat samples, and the isolated strains were confirmed by the invA gene presence (PCR technique). The strains were evaluated for antimicrobial susceptibility by the disk diffusion technique (Kirby-Bauer method) and tested for the presence of the sul2, blaCTX, and tetB antimicrobial resistance genes. The Salmonella spp. prevalence in chilled chicken meat sold at retail in the Federal District, Brazil, was 46.1% (53 of 115 chicken meat samples analyzed had invA gene-positive strains). Seventy-eight strains of Salmonella spp. isolated from the 53 contaminated samples showed higher resistance to amoxicillin/clavulanic acid (83.3%), followed by sulfonamide (64.1%) and tetracycline (46.2%); 53.8% of the isolates were multidrug-resistant (MDR). The sul2 gene that confers resistance to sulfonamide was found in 53 strains (68.0%), the blaCTX gene that confers resistance to beta-lactams was identified in 39 strains (50.0%), and the tetB gene that confers resistance to tetracycline was identified in 29 strains (37.2%). The high percentage of Salmonella contamination in chicken meat can pose a risk to consumers' health due to the possibility of causing salmonellosis. In addition, many isolates were MDR and carried antimicrobial resistance genes. Public agencies can use these results to develop effective public health policies and strategies to ensure the safety of these food products.

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.

Este trabalho teve como objetivo avaliar a qualidade microbiológica de carnes bovinas in natura resfriadas comercializadas em supermercados do Distrito Federal. Foram coletadas 16 amostras, sendo 8 amostras embaladas a vácuo (CA) e 8 amostras embaladas em bandeja de poliestireno envoltas em papel filme (CB). As análises microbiológicas incluíram a determinação de microrganismos mesófilos e psicrotróficos, coliformes totais e termotolerantes, Staphylococcus aureus e a pesquisa de Escherichia coli e Salmonella spp. Além disso, realizou-se o teste de suscetibilidade antimicrobiana das cepas de E. coli isoladas. Os resultados mostraram que 37,50% (6/16) das amostras ultrapassaram o limite permitido pela legislação brasileira de 2,00 log NMP/g para coliformes termotolerantes, sendo 2 amostras (12,50%) de CV e 4 amostras (25,00%) de CB. Nenhuma amostra apresentou contaminação por Salmonella spp. Em relação a bactéria S. aureus, 10 amostras (62,50%) estavam contaminadas, com contagens entre 2,00 e 2,88 log UFC/g, sendo que 4 amostras (25,00%) eram de CA e 6 amostras (37,50%) eram de CB. Foram confirmadas geneticamente 27 cepas de E. coli e observou-se o maior perfil de resistência antimicrobiana à sulfonamida (48,15%), além de perfis relevantes de resistência e sensibilidade intermediária para amoxicilina + ácido clavulânico (48,15%) e sensibilidade intermediária à ciprofloxacina (37,04%). Além disso, 22,22% (6/27) das cepas de E. coli apresentaram um perfil de multirresistência a antimicrobianos, caracterizado pela resistência a pelo menos três classes distintas de antibióticos. Assim, os resultados evidenciam preocupações quanto à qualidade microbiológica em carnes bovinas comercializadas no Distrito Federal, ressaltando a necessidade de melhores práticas sanitárias.

Introduction: Oregano (Origanum vulgare L

Introduction: Essential oils (EO), present in leaves, flowers, stems, and roots, are rich in terpenes and phenolic compounds, conferring antimicrobial and antioxidant activities