Essential Oil from the Leaves, Fruits and Twigs of Schinus terebinthifolius: Chemical Composition, Antioxidant and Antibacterial Potential.

Schinus terebinthifolius Raddi, popularly known as "Pink pepper", is a plant native to Brazil. The objective of this work was to analyze the chemical composition and the antioxidant and antibacterial potential of essential oils (EOs) from the leaves, fruits and twigs of S. terebinthifolius, aiming for their application in food safety. EOs were obtained by hydrodistillation and the chemical composition was determined by gas chromatography coupled to mass spectrometry. Phenolic compounds were quantified and antioxidant activity was evaluated using three different methods. The antibacterial activity was determined by the broth microdilution method against foodborne bacteria. In the chemical analysis, 22 compounds were identified in the leaves, 13 compounds in the fruits and 37 compounds in the twigs, revealing the presence of the main compounds germacrene D (12.04%, 15.78%, 20,41%), caryophyllene (15.97%, 3.12%, 11.73%), α-pinene (11.6%, 17.16%, 2.99%), ß-pinene (5.68%, 43.34%, 5.60%) and γ-gurjunene (16,85%, 3,15%) respectively. EOs showed better antioxidant potential using the ß-carotene/linoleic acid method with 40.74, 61.52 and 63.65% oxidation inhibition for leaves, fruits and twigs, respectively. The EO from the leaves showed greater antibacterial potential against Escherichia coli and Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 0.62 mg mL-1, a value lower than the MIC of sodium nitrite (5.00 mg mL-1), the antimicrobial standard synthetic. The activities of pink pepper EOs suggest their potential as a biopreservative in foods.

Antimicrobial resistance profile of gram-positive isolates belonging to the microbiota of non-human primates.

BACKGROUND: The aim of this work was to identify gram-positive bacteria and their respective resistance profiles of free-living capuchin monkeys. METHODS: For this, 15 Sapajus nigritus were captured in a municipal urban park in the northern region of the state of Paraná, Brazil, and under pharmacological restraint, samples were collected with sterile swabs from the oral, rectal, ocular, nasal, and auricular regions. After isolation of the 22 gram-positive bacteria, each isolate was subjected to the catalase and coagulase tests for presumptive identification. Subsequently, phenotypic tests for bacterial resistance were performed using the agar diffusion disc method. The samples resistant to oxacillin were submitted to the PCR technique to search for the mecA gene. RESULTS: Of the 22 gram-positive cocci of these two (9.09%) are Streptococcus spp. and twenty (90.91%) Staphylococcus spp. Among Staphylococcus spp. three (13.64%) were coagulate-negative (CoNS) and seventeen (86.36%) coagulate-positive (CoPS). Of the antimicrobials tested, enrofloxacin had the best performance, with only one (04.54%) isolate resistant to it, on the other hand, the antimicrobials with the lowest performance were cefotaxime and penicillin with 19 (82.36%) and 18 (81.81%) resistant isolates, respectively. Only five isolates had MAR less than 0.2, being one ocular, one oral, and three nasal, they had multiple resistance index varied between 0.07 and 0.92, with an average of 0.45 and a mode of 0.3. Among the samples with the highest resistance index, a positive coagulase Staphylococcus stood out, being intermediate to gentamicin and resistant to other antibiotics and an intermediate streptococcus to gentamicin, enrofloxacin, and resistant to other antibiotics. No sample was positive to mecA gene. CONCLUSIONS: Future studies should be conducted to identify the Staphylococcus species, the high rate of antimicrobial resistance of the monkeys in this study suggests that Grooming's behavior may be contributing to the sharing of the resistant microorganism among the members of this group of primates.

Short communication: Inhibitory activities of the lantibiotic nisin combined with phenolic compounds against Staphylococcus aureus and Listeria monocytogenes in cow milk.

We aimed to investigate the antibacterial activities of carvacrol, thymol, eugenol, cinnamaldehyde, and lantibiotic nisin against standard bacterial strains of the milk pathogens Staphylococcus aureus ATCC 25923 and Listeria monocytogenes ATCC 15313 in cow milk. The minimum inhibitory concentrations (MIC) of these substances were recorded. The synergistic effects were also assessed in culture medium (time kill curve) and in a food model (cow milk) during the storage period (4 °C for 6 d) after inoculation with S. aureus and L. monocytogenes individually by combining nisin and the phenolic compounds at proportions of 1/4 + 1/4 the MIC (determined in a previous in vitro assay) in the culture medium and 1/4 + 1/4 of MIC in the food model. Inhibitory activities of nisin and the tested compounds, as well as synergism in the combinations, were found against both bacteria assayed. Bacteriostatic effects were found with all combinations and a significant difference in L. monocytogenes reduction was found compared with the control assays. Thus, the antibacterial activity of nisin combined with phenolic compounds was confirmed against these pathogenic bacteria that are important in the milk industry, or more broadly in food science, with potential applications for milk preservation.

Sinergismo entre óleos essenciais e drogas antimicrobianas sobre linhagens de Staphylococcus aureus e Escherichia coli isoladas de casos clínicos humanos / Synergism between essential oils and antimicrobial drugs against Staphylooccus aureus and Escherichia coli strains from human infections

Estudos com plantas e utilização em terapias combinatórias têm sido estimulados. Verificou-se as possíveis interações entre óleos essenciais de plantas [canela (Cinnamomum zeylanicum Blume Lauraceae), capim-cidreira (Cymbopogon citratus (DC.) Stapf, Poaceae), hortelã-pimenta (Mentha piperita L. Lamiaceae), gengibre (Zingiber officinale Roscoe Zingiberaceae), cravo-da-índia (Caryophillus aromaticus L. Myrtaceae) e alecrim (Rosmarinus officinalis L. Lamiaceae)] combinados a oito drogas antimicrobianas frente a doze linhagens de Staphylococcus aureus e doze de Escherichia coli isoladas de humanos. Após determinação da Concentração Inibitória Mínima (CIM) para os óleos pelo método da diluição foram realizados ensaios para verificação de sinergismo entre os óleos essenciais e os antimicrobianos pela metodologia de Kirby & Bauer. S. aureus foi mais suscetível às interações óleos e drogas, tendo o óleo de capim cidreira apresentado sinergismo com as oito drogas testadas, seguido pelo óleo de hortelã com sete drogas. Nos ensaios com E. coli, houve sinergismo apenas para os óleos de alecrim (três drogas) e capim-cidreira (duas drogas). Não ocorreram casos de antagonismo e os resultados de sinergismo foram influenciados pelos microrganismos estudados.

The studies with plants and combinatory therapy have been stimulated. The interactions between cinnamon (Cinnamomun zeylanicum Blume Lauraceae), lemon grass (Cymbopogon citratus (DC.) Stapf, Poaceae), mint (Mentha piperita L. Lamiaceae), ginger (Zingiber officinale Roscoe Zingiberaceae), clove (Caryophillus aromaticus L. Myrtaceae) and rosemary (Rosmarinus officinalis L. Lamiaceae) and eight antimicrobial drug was carried. It was made against twelve S. aureus and twelve E.coli strains isolated from human specimens. After minimal inhibitory concentration (MIC) values determination of essential oils by dilution agar method, the synergism assays were performed by Kirby and Bauer method. The S. aureus was susceptible to oils and drugs interactions, and the lemon grass oils showed synergism with all drugs tested followed by mint with seven drugs. E.coli assays, synergism was observed only with rosemary (three drugs) and lemon grass (two drugs). No antagonism between drugs and oils tested was observed and the results were variable according to microorganism used.