Antibacterial Efficiency of Tanacetum vulgare Essential Oil against ESKAPE Pathogens and Synergisms with Antibiotics.

Medicinal plants with multiple targets of action have become one of the most promising solutions in the fight against multidrug-resistant (MDR) bacterial infections. Tanacetum vulgare (Tansy) is one of the medicinal plants with antibacterial qualities that deserve to be studied. Thus, this research takes a closer look at tansy extract's composition and antibacterial properties, aiming to highlight its potential against clinically relevant bacterial strains. In this respect, the antibacterial test was performed against several drug-resistant pathogenic strains, and we correlated them with the main isolated compounds, demonstrating the therapeutic properties of the extract. The essential oil was extracted via hydrodistillation, and its composition was characterized via gas chromatography. The main isolated compounds known for their antibacterial effects were α-Thujone, ß-Thujone, Eucalyptol, Sabinene, Chrysanthenon, Camphor, Linalool oxide acetate, cis-Carveol, trans-Carveyl acetate, and Germacrene. The evaluation of the antibacterial activity was carried out using the Kirby-Bauer and binary microdilution methods on Gram-positive and Gram-negative MDR strains belonging to the ESKAPE group (i.e., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.). Tansy essential oil showed MIC values ranging from 62.5 to 500 µg/mL against the tested strains. Synergistic activity with different classes of antibiotics (penicillins, cephalosporins, carbapenems, monobactams, aminoglycosides, and quinolones) has also been noted. The obtained results demonstrate that tansy essential oil represents a promising lead for developing new antimicrobials active against MDR alone or in combination with antibiotics.

Landscape of Genetic Mutations in Appendiceal Cancers.

In appendiceal cancers, the most frequently mutated genes are (i) KRAS, which, when reactivated, restores signal transduction via the RAS-RAF-MEK-ERK signaling pathway and stimulates cell proliferation in the early stages of tumor transformation, and then angiogenesis; (ii) TP53, whose inactivation leads to the inhibition of programmed cell death; (iii) GNAS, which, when reactivated, links the cAMP pathway to the RAS-RAF-MEK-ERK signaling pathway, stimulating cell proliferation and angiogenesis; (iv) SMAD4, exhibiting typical tumor-suppressive activity, blocking the transmission of oncogenic TGFB signals via the SMAD2/SMAD3 heterodimer; and (v) BRAF, which is part of the RAS-RAF-MEK-ERK signaling pathway. Diverse mutations are reported in other genes, which are part of secondary or less critical signaling pathways for tumor progression, but which amplify the phenotypic diversity of appendiceal cancers. In this review, we will present the main genetic mutations involved in appendix tumors and their roles in cell proliferation and survival, and in tumor invasiveness, angiogenesis, and acquired resistance to anti-growth signals.

Phenotypic and genetic virulence and antibiotic resistance markers in Escherichia coli strains isolated from hospital surfaces.

The aim of this study was the phenotypic and genotypic analysis of the antibiotic resistance and virulence markers in enterobacterial strains isolated from the hospital environment. In this purpose, 100 enterobacterial strains isolated from hospital surfaces were investigated for their susceptibility patterns, for the ability to colonize the cellular (HeLa) and inert substrate and for the production of soluble, enzymatic factors. The bacterial strains were also investigated for the presence of resistance and virulence genes (aggR, aggA, EaggEC, EAST1, hlyA). The enterobacterial strains isolated from the hospital surfaces exhibited high levels resistance rates to beta-lactams, including 3'd generation cephalosporins, teteracyclines, sulphametoxazole and nalidixic acid. The PCR analysis demonstrated the presence of TEM1, tetA, tetB, tetC, dfrA12, sulI and sulII in a low percentage of the resistant strains. The majority of the tested strains exhibited ability to colonize the inert and cellular substrate and also the ability to produce a series of soluble enzymes implicated in enteric and extra-intestinal pathogenesis (pore forming enzymes, proteases, mucinases, iron chelating agents). The presence of beta-haemolysis on sheep blood agar was well correlated with the presence of hlyA gene, while the aggregative adherence pattern with the presence of aggA, aggR and EAST/1 genes, in different combinations. Our results are demonstrating that the E. coli strains isolated from the hospital environment harbor phenotypic and genetic virulence markers, thus contributing to the development of resistance and virulence genes reservoirs with potential implication for the human health in the hospital environment.

Novel antipathogenic strategies against adherent enterobacterial strains isolated from the hospital environment.

The emergence of the bacterial antibiotic multi-resistance made more and more stringent the developing of new anti-microbial strategies. The purpose of the present study was to investigate the antimicrobial potential of six (6) newly synthesized chemical compounds (derivating from phenantroline and dimethylguanin-copper complex combinations) versus 97 enterobacterial strains isolated from the hospital environment. The qualitative screening of the antimicrobial activity of the chemical compounds was performed by an adapted diffusion method. The minimal inhibitory concentrations (MIC) of the active chemical compounds were established by Mueller Hinton broth microdillution method. The tested chemical compounds were also tested for their ability to inhibit microbial adherence and biofilm development on inert substrata by a simple microtiter method. All six chemical compounds proved to have antimicrobial activity versus the most of the tested strains, the phenantroline derivatives exhibiting higher antimicrobial activity than the dimethylguanidine-copper complex combinations. The subinhibitory concentrations of the tested chemical products slightly inhibited the adherence ability of the bacterial strains to the inert substratum. Our results demonstrated that phenantroline derivatives may represent a new strategy of antimicrobial treatment, simultaneously with the bactericidal effect, the subinhibitory concentrations of these newly synthesized chemical compounds decreasing the adherence ability of bacteria to the inert substratum.