Search results for "Anti-Bacterial Agents"
showing 10 items of 661 documents
Sindrome nefrosica e sepsi da Gram negativi in corso di strongiloidiasi: considerazioni su un caso in immigrato imunocompetente
2007
Strongyloidiasis is caused by a small intestinal nematode with a complex life cycle. In Italy the infection is endemic in rural areas of the Po Valley. The clinical syndrome of S. stercoralis encompasses a broad spectrum of symptoms and signs and, in the immunocompromised host, larvae can migrate to different organs and tissues. Also immune response seems to play a role in the pathogenesis of the disease. We report a case of strongyloidiasis complicated by Gram-negative sepsis and nephrotic syndrome in an immigrant from South America with a normal immune response. Whereas sepsis cleared up quickly, parasitic clearance was obtained only after treatment with ivermectin and nephrotic syndrome …
Anthemis wiedemanniana essential oil prevents LPS-induced production of NO in RAW 264.7 macrophages and exerts antiproliferative and antibacterial ac…
2012
Anthemis wiedemanniana is known in folk medicine for the treatment of microbial infections, cancer and also urinary and pulmonary problems. In this study, the chemical composition of the essential oil from A. wiedemanniana was evaluated and its antibacterial activity was tested against 10 bacterial strains. The oil was also tested for its potentiality to inhibit nitric oxide production in RAW 264.7 macrophages and for its cytotoxicity against four human cancer cell lines. A. wiedemanniana oil, rich of oxygenated monoterpenes (25.4%), showed a good antibacterial activity against Gram-positive bacteria and a good activity against the two Gram-negative bacteria, Escherichia coli and Proteus vu…
Antibacterial and anticoagulant activities of coumarins isolated from the flowers of Magydaris tomentosa (Desf.) DC (Apiaceae)
2007
The phytochemical investigation of the acetone and methanol extracts of the flowers of Magydaris tomentosa (Desf.) DC afforded six known coumarins as well as (+)-meranzin hydrate (7), not previously reported as a natural product. The antibacterial activity of umbelliprenin (1), osthol (2), imperatorin (3), citropten (4) and (+)-meranzin hydrate (7) was tested against Gram-positive and Gram-negative bacteria. All coumarins (1-7) isolated in this study inhibited growth of all bacterial strains tested (MIC between 16 and 256 μg/mL), the most active being imperatorin (3) (MICs between 32 and 128 μg/mL) and citropten (4) (MICs between 16 and 256 μg/mL). The anticoagulant activity of compounds 1-…
Chemical composition of the essential oil from Thapsia garganica L. (Apiaceae) grown wild in Sicily and its antimicrobial activity.
2015
In this study, the chemical composition of the essential oil from flowers and leaves of Thapsia garganica L. collected in Sicily was evaluated by GC and GC-MS. The main components of T. garganica flower oil (T.f.) were chamazulene (58.3%), humulene oxide II (9.0%), tricosane (8.2%) and pentacosane (8.2%). Also the oil from leaves (T.l.) was characterised by high content of chamazulene (49.2%). Other abundant metabolites were 1,4-dimethylazulene (18.5%), (E)-phytol (6.3%) and neophytadiene (5.1%). The comparison with other studied oils of genus Thapsia is discussed. Antimicrobial activity against several micro-organisms, including some ones infesting historical art craft, was also determined.
Antibiotic Resistance of Gram Negatives isolates from loggerhead sea turtles (Caretta caretta) in the central Mediterranean Sea
2009
Previous studies on fish and marine mammals support the hypothesis that marine species harbor antibiotic resistance and therefore may serve as reservoirs for anti biotic-resistance genetic determinants. The aim of this study was to assess the resistance to antimicrobial agents of Gram negative strains isolated from loggerhead sea turtles (Caretta caretta). Oral and cloacal swabs from 19 live-stranded loggerhead sea turtles, with hooks fixed into the gut, were analyzed. The antimicrobial resistance of the isolates to 31 antibiotics was assessed using the disk-diffusion method. Conventional biochemical tests identified Citrobacter spp., Proteus spp., Enterobacter spp., Escherichia spp., Provi…
A membrane computing simulator of trans-hierarchical antibiotic resistance evolution dynamics in nested ecological compartments (ARES)
2015
In this article, we introduce ARES (Antibiotic Resistance Evolution Simulator) a software device that simulates P-system model scenarios with five types of nested computing membranes oriented to emulate a hierarchy of eco-biological compartments, i.e. a) peripheral ecosystem; b) local environment; c) reservoir of supplies; d) animal host; and e) host's associated bacterial organisms (microbiome). Computational objects emulating molecular entities such as plasmids, antibiotic resistance genes, antimicrobials, and/or other substances can be introduced into this framework and may interact and evolve together with the membranes, according to a set of pre-established rules and specifications. AR…
Bacterial metal nanoparticles to develop new weapons against bacterial biofilms and infections
2021
The widespread use of antibiotics has resulted in the outbreak and spread of antibiotic-resistant pathogens. Bacterial antibiotic resistance may develop at cellular and community levels. In the latter case, it is based on tolerance which implicates the shift from a free-living form of life (i.e., planktonic) to a sessile multi-stratified community (i.e., biofilm). Metal nanoparticles (MNPs) have been shown to be promising candidates as antimicrobial agents. MNPs are able to interact with and penetrate bacterial biofilms, thus, resulting effective antibiofilm compounds. Another interesting aspect is the possibility of using plants, fungi, yeasts, and bacteria to obtain biogenic MNPs (BMNP). …
Synthetic small molecules as anti-biofilm agents in the struggle against antibiotic resistance
2018
Abstract Biofilm formation significantly contributes to microbial survival in hostile environments and it is currently considered a key virulence factor for pathogens responsible for serious chronic infections. In the last decade many efforts have been made to identify new agents able to modulate bacterial biofilm life cycle, and many compounds have shown interesting activities in inhibiting biofilm formation or in dispersing pre-formed biofilms. However, only a few of these compounds were tested using in vivo models for their clinical significance. Contrary to conventional antibiotics, most of the anti-biofilm compounds act as anti-virulence agents as they do not affect bacterial growth. I…
Glycoprotein molecules in the walls of Schizosaccharomyces pombe wild-type cells and a morphologically altered mutant resistant to papulacandin B
1990
SUMMARY: Schizosaccharomyces pombe cell walls contain two major glycoprotein species, I and II, with molecular masses of 2 x 106 and 5 x 105 Da respectively, as determined by gel filtration chromatography and PAGE. The ratio of sugar to protein is higher in species I than in species II. Much of the sugar in both glycoproteins (about 85% in wild-type cells) is O-linked to the peptide moiety. The morphological sph1 mutant is resistant to papulacandin B, and its cell wall contains less glycoprotein II (but not less glycoprotein I) than the parental wild-type strain, although glycoprotein II is still synthesized and released into the growth medium. Papulacandin B largely reverses the morphologi…
Isolation and characterization of Saccharomyces cerevisiae mutants resistant to aculeacin A
1991
Aculeacin A is a lipopeptide that inhibits beta-glucan synthesis in yeasts. A number of Saccharomyces cerevisiae mutants resistant to this antibiotic were isolated, and four loci (ACR1, ACR2, ACR3, and ACR4) whose products are involved in the sensitivity to aculeacin A of yeast cells were defined. Mutants containing mutations in the four loci were also resistant to echinocandin B, another member of this lipopeptide family of antibiotics. In contrast, acr1, acr3, and acr4 mutants were resistant to papulacandin B (an antibiotic containing a disaccharide linked to two fatty acid chains that also inhibits beta-glucan synthesis), but acr2 mutants were susceptible to this antibiotic. This result …