Antimicrobial and anti-biofilm activities of plant extracts against Pseudomonas aeruginosa – a review

Antimicrobial resistance among bacterial pathogens, including Pseudomonas aeruginosa, is a global problem that has led to research on naturally occurring compounds as an alternative source of antibacterial and anti-biofilm agents. This review focuses on determining plant extracts' antimicrobial and anti-biofilm activities against P. aeruginosa, an opportunistic pathogen contributing to microbial and biofilm-associated infections in humans. Medicinal plants are being widely researched as they are rich sources of phytochemicals, including flavonoids, alkaloids, tannins and terpenoids. These phytochemicals have been well known for their antibacterial activity, which contributes to the effectiveness of certain plants, including Punica granatum and Triumfetta welwitschia, against P. aeruginosa. Hypericum perforatum and Berginia ciliata contains phytochemicals that directly inhibit the quorum sensing mechanism, inhibiting the direct cell-to-cell communication, thereby preventing or reducing biofilm formation by P. aeruginosa. Plant extracts also inhibit bacterial growth and should be considered an alternative to antibiotics. Furthermore, plant extracts can be used with antibiotics for better efficacy against P. aeruginosa. However, more research must be carried out to select plants with a broad spectrum of activity against not only P. aeruginosa infections but other gram-negative bacteria in general. It would be economically viable to develop as a therapeutic drug. This would align with the third United Nations sustainable development goals on good health and well-being and is a significant step forward in the battle against antibiotic resistance

Efficacy of phenotypic, PCR and MALDI -ToF identification methods for Campylobacter spp.

This study compared phenotypic and genotypic identification methods of Campylobacter spp. against the polymerase chain reaction (PCR) in terms of sensitivity, specificity, positive-predictive value and negative-predictive value. Thermophilic Campylobacter isolates were identified using conventional biochemical tests, specifically hippurate hydrolysis, matrix assisted laser desorption ionization- time of flight (MALDI-ToF) mass spectrometry and PCR with primers unique to C. jejuni and C. coli. MALDI-ToF was shown to be superior to biochemical tests for identification of C. coli but equivalent to biochemical tests for C. jejuni.The National Research Foundation Thuthuka: Researchers in Training Programme Ref. TTK2007040500009http://www.smltsa.org.zaam2017Physiolog

Rapid bioassay-guided isolation of antibacterial clerodane type diterpenoid from Dodonaea viscosa (L.) Jaeq

Plant extracts are complex matrices and, although crude extracts are widely in use, purified compounds are pivotal in drug discovery. This study describes the application of automated preparative-HPLC combined with a rapid off-line bacterial bioassay, using reduction of a tetrazolium salt as an indicator of bacterial metabolism. This approach enabled the identification of fractions from Dodonaea viscosa that were active against Staphylococcus aureus and Escherichia coli, which, ultimately, resulted in the identification OPEN ACCESS of a clerodane type diterpenoid, 6\u3b2-hydroxy-15,16-epoxy-5\u3b2, 8\u3b2, 9\u3b2, 10\u3b1-cleroda-3, 13(16), 14-trien-18-oic acid, showing bacteriostatic activity (minimum inhibitory concentration (MIC) = 64\u2013128 \u3bcg/mL) against test bacteria. To the best of our knowledge, this is the first report on antibacterial activity of this metabolite from D. viscosa

Neoadjuvant Chemotherapy, Endocrine Therapy, and Targeted Therapy for Breast Cancer: ASCO Guideline

PURPOSE: To develop guideline recommendations concerning optimal neoadjuvant therapy for breast cancer. METHODS: ASCO convened an Expert Panel to conduct a systematic review of the literature on neoadjuvant therapy for breast cancer and provide recommended care options. RESULTS: A total of 41 articles met eligibility criteria and form the evidentiary basis for the guideline recommendations. RECOMMENDATIONS: Patients undergoing neoadjuvant therapy should be managed by a multidisciplinary care team. Appropriate candidates for neoadjuvant therapy include patients with inflammatory breast cancer and those in whom residual disease may prompt a change in therapy. Neoadjuvant therapy can also be used to reduce the extent of local therapy or reduce delays in initiating therapy. Although tumor histology, grade, stage, and estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) expression should routinely be used to guide clinical decisions, there is insufficient evidence to support the use of other markers or genomic profiles. Patients with triple-negative breast cancer (TNBC) who have clinically node-positive and/or at least T1c disease should be offered an anthracycline- and taxane-containing regimen; those with cT1a or cT1bN0 TNBC should not routinely be offered neoadjuvant therapy. Carboplatin may be offered to patients with TNBC to increase pathologic complete response. There is currently insufficient evidence to support adding immune checkpoint inhibitors to standard chemotherapy. In patients with hormone receptor (HR)-positive (HR-positive), HER2-negative tumors, neoadjuvant chemotherapy can be used when a treatment decision can be made without surgical information. Among postmenopausal patients with HR-positive, HER2-negative disease, hormone therapy can be used to downstage disease. Patients with node-positive or high-risk node-negative, HER2-positive disease should be offered neoadjuvant therapy in combination with anti-HER2-positive therapy. Patients with T1aN0 and T1bN0, HER2-positive disease should not be routinely offered neoadjuvant therapy.Additional information is available at www.asco.org/breast-cancer-guidelines

Mistranslation Drives Alterations in Protein Levels and the Effects of a Synonymous Variant at the Fibroblast Growth Factor 21 Locus

Fibroblast growth factor 21 (FGF21) is a liver-derived hormone with pleiotropic beneficial effects on metabolism. Paradoxically, FGF21 levels are elevated in metabolic diseases. Interventions that restore metabolic homeostasis reduce FGF21. Whether abnormalities in FGF21 secretion or resistance in peripheral tissues is the initiating factor in altering FGF21 levels and function in humans is unknown. A genetic approach is used to help resolve this paradox. The authors demonstrate that the primary event in dysmetabolic phenotypes is the elevation of FGF21 secretion. The latter is regulated by translational reprogramming in a genotype- and context-dependent manner. To relate the findings to tissues outcomes, the minor (A) allele of rs838133 is shown to be associated with increased hepatic inflammation in patients with metabolic associated fatty liver disease. The results here highlight a dominant role for translation of the FGF21 protein to explain variations in blood levels that is at least partially inherited. These results provide a framework for translational reprogramming of FGF21 to treat metabolic diseases

Soil mineral nitrogen benefits derived from legumes and comparisons of the apparent recovery of legume or fertiliser nitrogen by wheat

Nitrogen (N) contributed by legumes is an important component of N supply to subsequent cereal crops, yet few Australian grain-growers routinely monitor soil mineral N before applying N fertiliser. Soil and crop N data from 16 dryland experiments conducted in eastern Australia from 1989–2016 were examined to explore the possibility of developing simple predictive relationships to assist farmer decision-making. In each experiment, legume crops were harvested for grain or brown-manured (BM, terminated before maturity with herbicide), and wheat, barley or canola were grown. Soil mineral N measured immediately before sowing wheat in the following year was significantly higher (P < 0.05) after 31 of the 33 legume pre-cropping treatments than adjacent non-legume controls. The average improvements in soil mineral N were greater for legume BM (60 ± 16 kg N/ha; n = 5) than grain crops (35 ± 20 kg N/ha; n = 26), but soil N benefits were similar when expressed on the basis of summer fallow rainfall (0.15 ± 0.09 kg N/ha per mm), residual legume shoot dry matter (9 ± 5 kg N/ha per t/ha), or total legume residue N (28 ± 11%). Legume grain crops increased soil mineral N by 18 ± 9 kg N/ha per t/ha grain harvested. Apparent recovery of legume residue N by wheat averaged 30 ± 10% for 20 legume treatments in a subset of eight experiments. Apparent recovery of fertiliser N in the absence of legumes in two of these experiments was 64 ± 16% of the 51–75 kg fertiliser-N/ha supplied. The 25 year dataset provided new insights into the expected availability of soil mineral N after legumes and the relative value of legume N to a following wheat crop, which can guide farmer decisions regarding N fertiliser use.Mark B. Peoples, Antony D. Swan, Laura Goward, John A. Kirkegaard, James R. Hunt, Guangdi D. Li, Graeme D. Schwenke, David F. Herridge, Michael Moodie, Nigel Wilhelm, Trent Potter, Matthew D. Denton, Claire Browne, Lori A. Phillips, and Dil Fayaz Kha

A mechanistic model of small intestinal starch digestion and glucose uptake in the cow

The high contribution of postruminal starch digestion (up to 50%) to total-tract starch digestion on energy-dense, starch-rich diets demands that limitations to small intestinal starch digestion be identified. A mechanistic model of the small intestine was described and evaluated with regard to its ability to simulate observations from abomasal carbohydrate infusions in the dairy cow. The 7 state variables represent starch, oligosaccharide, glucose, and pancreatic amylase in the intestinal lumen, oligosaccharide and glucose in the unstirred water layer at the intestinal wall, and intracellular glucose of the enterocyte. Enzymatic hydrolysis of starch was modeled as a 2-stage process involving the activity of pancreatic amylase in the lumen and of oligosaccharidase at the brush border of the enterocyte confined within the unstirred water layer. The Na+-dependent glucose transport into the enterocyte was represented along with a facilitative glucose transporter 2 transport system on the basolateral membrane. The small intestine is subdivided into 3 main sections, representing the duodenum, jejunum, and ileum for parameterization. Further subsections are defined between which continual digesta flow is represented. The model predicted nonstructural carbohydrate disappearance in the small intestine for cattle unadapted to duodenal infusion with a coefficient of determination of 0.92 and a root mean square prediction error of 25.4%. Simulation of glucose disappearance for mature Holstein heifers adapted to various levels of duodenal glucose infusion yielded a coefficient of determination of 0.81 and a root mean square prediction error of 38.6%. Analysis of model behavior identified limitations to the efficiency of small intestinal starch digestion with high levels of duodenal starch flow. Limitations to individual processes, particularly starch digestion in the proximal section of the intestine, can create asynchrony between starch hydrolysis and glucose uptake capacity