Structure-Activity Relationship Study to Develop Peptide Amphiphiles as Species-Specific Antimicrobials.

Antimicrobial peptide amphiphiles (PAs) are a promising class of molecules that can disrupt the bacterial membrane or act as drug nanocarriers. In this study, we prepared 33 PAs to establish supramolecular structure-activity relationships. We studied the morphology and activity of the nanostructures against different Gram-positive and Gram-negative bacterial strains (such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii). Next, we used principal component analysis (PCA) to determine the key contributors to activity. We found that for S. aureus, the zeta potential was the major contributor to the activity while Gram-negative bacteria were more influenced by the partition coefficient (LogP) with the following order P. aeruginosa>E. coli>A. baumannii. We also performed a study of the mechanism of action of selected PAs on the bacterial membrane assessing the membrane permeability and depolarization, changes in zeta potential and overall integrity. We studied the toxicity of the nanostructures against mammalian cells. Finally, we performed an in vivo study using the wax moth larvae to determine the therapeutic efficacy of the active PAs. This study shows cationic PA nanostructures can be an intriguing platform for the development of nanoantibacterials.

Mediating pathways that link adverse childhood experiences with cardiovascular disease.

OBJECTIVES: There is uncertainty about which factors mediate the association between adverse childhood experiences (ACEs) and cardiovascular disease (CVD). This could inform secondary prevention targets. STUDY DESIGN: Mediation analysis of a prospective cohort study. METHODS: English Longitudinal Study of Ageing (ELSA) wave 3 data (2006/7) were used to measure retrospective exposure to 12 individual ACEs and waves 2 to 4 (2004/5 to 2008/9) data to measure current exposure to potential mediators [smoking, physical activity, alcohol consumption, body mass index, depression, and C-reactive protein (CRP)]. Waves 4 to 9 ELSA data (2008/9 to 2018/19) were used to measure incident CVD. Cumulative ACE exposure was categorised into experiencing 0, 1 to 3, or ≥4 individual ACEs. Associations were tested between ACE categories, potential mediators, and incident CVD, to inform which variables were analysed in causal mediation models. RESULTS: The analytical cohort consisted of 4547 participants (56% women), with a mean age of 64 years (standard deviation = 9 years). At least one ACE had been experienced by 45% of the cohort, and 24% developed incident CVD over a median follow-up period of 9.7 years (interquartile range: 5.3-11.4 years). After adjusting for potential confounders, experiencing ≥4 ACEs compared with none was associated with incident CVD [odds ratio (OR): 1.55; 95% confidence interval (CI): 1.10, 2.17], and the association of one to three ACEs compared with none was non-significant (OR: 1.08; 95% CI: 0.93, 1.24). There were two statistically significant mediators of the association between ≥4 ACEs and incident CVD: CRP and depression, which accounted for 10.7% and 10.8% of the association, respectively. CONCLUSIONS: Inflammation and depression partially mediated the association between ACEs and CVD. Targeting these factors may reduce the future incidence of CVD.

Design and Synthesis of Novel 3-Nitro-1H-1,2,4-triazole-1,2,3-triazole-1,4-disubstituted Analogs as Promising Antitrypanosomatid Agents: Evaluation of In Vitro Activity against Chagas Disease and Leishmaniasis.

A series of 28 compounds, 3-nitro-1H-1,2,4-triazole, were synthesized by click-chemistry with diverse substitution patterns using medicinal chemistry approaches, such as bioisosterism, Craig-plot, and the Topliss set with excellent yields. Overall, the analogs demonstrated relevant in vitro antitrypanosomatid activity. Analog 15g (R1 = 4-OCF3-Ph, IC50 = 0.09 µM, SI = >555.5) exhibited an outstanding antichagasic activity (Trypanosoma cruzi, Tulahuen LacZ strain) 68-fold more active than benznidazole (BZN, IC50 = 6.15 µM, SI = >8.13) with relevant selectivity index, and suitable LipE = 5.31. 15g was considered an appropriate substrate for the type I nitro reductases (TcNTR I), contributing to a likely potential mechanism of action for antichagasic activity. Finally, 15g showed nonmutagenic potential against Salmonella typhimurium strains (TA98, TA100, and TA102). Therefore, 3-nitro-1H-1,2,4-triazole 15g is a promising antitrypanosomatid candidate for in vivo studies.

In vitro antifungal activity of Myracrodruon urundeuva Allemão against human vaginal Candida species

ABSTRACT Myracrodruon urundeuva is a plant native to Brazil, which is used by the indigenous population for the treatment of candidiasis. The aims of this study were to evaluate the antifungal activity of extract against human vaginal Candida species and evaluate the possible toxicological activities of M. urundeuva. Initially, ethanol extracts, ethyl acetate fractions, and hydroalcoholic fractions of the bark and leaf of M. urundeuva were used to determine the minimum inhibitory concentration. The extracts that showed antifungal activity were characterized by liquid chromatography and subjected to toxicity assessment. Toxic, cytotoxic, genotoxic, and mutagenic testing were performed using Allium cepa and Ames assays with the ethanol extracts of the bark and leaves. Hemolytic activity was evaluated in erythrocytes and acute toxicity in rats. The ethanol bark extracts showed best activity against Candida albicans, C. krusei, and C. tropicalis ATCC (4-512 µg/mL). Chemical characterization indicated the presence of flavonoids and tannins in the extracts. Hemolytic activity, genotoxicity, and mutagenicity were not observed. The results of the Ames and A. cepa tests were also in agreement, ethanol bark extracts and ethanol leaf extracts of M. urundeuva showed absence of mutagenic activity. Similar results were observed in the A. cepa assay and acute toxicity test in rats. M. urundeuva bark extracts showed potential for the treatment of vaginal infections caused Candida species, as a topical.

Antimicrobial susceptibility profile of Pseudomonas spp. isolated from a swine slaughterhouse in Dourados, Mato Grosso do Sul State, Brazil / Antimicrobial susceptibility profile of Pseudomonas spp. isolated from a swine slaughterhouse in Dourados, Mato Grosso do Sul State, Brazil.

The present work sought to detect the presence of Pseudomonas spp. at different stages of an effluent treatment plant using the Australian system of stabilization ponds, and to determine the susceptibility of those isolates to different antimicrobials. Thirty-four isolates of Pseudomonas spp. derived from effluent treatment station water samples were collected near the transfer ducts between the ponds in November/2008 and december/2009. Among the Pseudomonas spp. isolates, 47.05

showed susceptibility to all antimicrobials tested, 20.58

were resistant to cefepime, and 24

showed intermediate resistance to streptomycin. No Pseudomonas spp. isolates were found in the final pond, or in post-treatment effluents. The Pseudomonas spp. isolates did not exhibit multiresistance to the antimicrobials tested.

Antimicrobial susceptibility profile of Pseudomonas spp. isolated from a swine slaughterhouse in Dourados, Mato Grosso do Sul State, Brazil. / Antimicrobial susceptibility profile of Pseudomonas spp. isolated from a swine slaughterhouse in Dourados, Mato Grosso do Sul State, Brazil.

The present work sought to detect the presence of Pseudomonas spp. at different stages of an effluent treatment plant using the Australian system of stabilization ponds, and to determine the susceptibility of those isolates to different antimicrobials. Thirty-four isolates of Pseudomonas spp. derived from effluent treatment station water samples were collected near the transfer ducts between the ponds in November/2008 and december/2009. Among the Pseudomonas spp. isolates, 47.05

showed susceptibility to all antimicrobials tested, 20.58

were resistant to cefepime, and 24

showed intermediate resistance to streptomycin. No Pseudomonas spp. isolates were found in the final pond, or in post-treatment effluents. The Pseudomonas spp. isolates did not exhibit multiresistance to the antimicrobials tested.