Inhibition of Bacterial Adhesion and Biofilm Formation by Seed-Derived Ethanol Extracts from Persea americana Mill.

The increase in antibiotic resistance demands innovative strategies to combat microorganisms. The current study evaluated the antibacterial and antivirulence effects of ethanol extracts from Persea americana seeds obtained by the Soxhlet (SE) and maceration (MaE) methods. The UHPLC-DAD-QTOF analysis showed mainly the presence of polyphenols and neolignan. Ethanol extracts were not cytotoxic to mammalian cells (CC50 > 500 µg/mL) and displayed a moderate antibacterial activity against Pseudomonas aeruginosa (IC50 = 87 and 187 µg/mL) and Staphylococcus aureus (IC50 = 144 and 159 µg/mL). Interestingly, no antibacterial activity was found against Escherichia coli. SE and MaE extracts were also able to significantly reduce the bacterial adhesion to A549 lung epithelial cells. Additionally, both extracts inhibited the biofilm growth at 24 h and facilitated the release of internal cell components in P. aeruginosa, which might be associated with cell membrane destabilization. Real-time PCR and agarose electrophoresis gel analysis indicated that avocado seed ethanol extracts (64 µg/mL) downregulated virulence-related factors such as mexT and lasA genes. Our results support the potential of bioproducts from P. americana seeds as anti-adhesive and anti-biofilm agents.

LC-MS Characterization and Biological Activities of Cuban Cultivars of Plectranthus neochilus Schltr.

Plectranthus neochilus Schltr. (Lamiaceae) is a plant recently introduced in Cuba. Worldwide, it is an ethnomedicinal alternative for its use against microbial infections, but the Cuban population use the extracts to treat sleep disorders. To address this apparent incongruity, four collections (from different seasonal conditions in the year) of Cuban P. neochilus cultivars were analyzed in terms of their pharmacognostic characteristics. Three extracts using fresh and dried leaves were chemically and biologically characterized. UPLC-DAD-MS/MS analysis was performed to determine their chemical composition, while a panel of nine microorganisms was used to evaluate their antimicrobial activity. Finally, cytotoxic effects of different fractions were measured in three cell lines by the resazurin viability assay. In contrast to previously reported micro and macromorphological properties of P. neochilus, the leaves from the Cuban cultivars did not present glandular trichomes, nor did they produce quantifiable levels of essential oils. Moreover, aqueous extracts used by the population revealed no significant antimicrobial activity and were not cytotoxic. The three extracts showed a similar phytochemical composition, i.e., eight flavonoids, seven abietane diterpenes, and rosmarinic acid as the major constituent, most of them reported for the first time in this species. The low yield of essential oil, the absence of glandular trichomes, compounds with a high level of oxidation, and a moderate antimicrobial activity detected were the most distinctive pharmacognostic and biological characteristics of P. neochilus grown in Cuba. These aspects could explain its non-use as an antimicrobial.

Should Screening for Chlamydia Trachomatis Be Performed on Asymptomatic Young Adults as well as on the Victims of Sexual Assault?

In recent years, chlamydia trachomatis (CT) screening has been discussed among different scientific boards. However, in Spain, chlamydia screening is offered to women who attend a hospital after sexual assault. We found that 5.1% of 59 cases attending our hospital after sexual assault between January 2017 and December 2019 tested positive for chlamydia infection. The mean age of the cases was 23.3 years. In comparison, screening asymptomatic patients of similar age attending hospital for other reasons have revealed a prevalence of CT of 7%. Hence, since CT is common in asymptomatic individuals as well as victims of sexual assault, we believe that chlamydia screening should also be a priority in asymptomatic patients.

Efficacy in reducing potassium load in irradiated red cell bags with a potassium adsorption filter.

BACKGROUND: The transfusion of red cell (RBC) bags with high amounts of potassium (K(+)) causes concern about an increased risk of cardiac arrest because of transient hyperkalemia. To prevent K(+) overload, a K(+) adsorption filter (PAF) is available for use at bedside. The aim of the present study was to analyze the efficacy in reducing K(+) load in irradiated RBC bags with this PAF. STUDY DESIGN AND METHODS: Whole-blood (WB) bags were collected from volunteer donors on Day 0. RBC bags were prepared from WB bags on Day +1 and stored at 2 to 6 degrees C. RBC bags were irradiated on Day +14 and filtered with the PAF on Day +28, according to the manufacturers' instructions. The plasma electrolyte levels (Na(+), K(+), Cl(-), Ca(2+), and Mg(2+)) were measured at the different points during storage. RESULTS: Twelve RBC bags were prepared with a final volume of 274 +/- 15 mL. On Day +28, the volume of RBC bags was 257 +/- 15 mL, and the PAF was used at a flow rate of 4 +/- 0.7 mL per minute. K(+) level after RBC bag preparation was 1.28 +/- 0.59 mmol per L. The K(+) level was 60.6 +/- 2.68 mmol per L on Day +28, just before filtration with the PAF. After filtration, the level of K(+) was 3.42 +/- 2.91 mmol per L. CONCLUSION: This study has shown a high efficacy in reducing potassium load in irradiated RBC bags with the use of the PAF.