scholarly journals Biomimetic Approaches for the Development of New Antifouling Solutions: Study of Incorporation of Macroalgae and Sponge Extracts for the Development of New Environmentally-Friendly Coatings

2019 ◽  
Vol 20 (19) ◽  
pp. 4863 ◽  
Author(s):  
Ilse Sánchez-Lozano ◽  
Claudia Judith Hernández-Guerrero ◽  
Mauricio Muñoz-Ochoa ◽  
Claire Hellio
Keyword(s):  
Biofilm Formation ◽  
Gulf Of California ◽  
Environmentally Friendly ◽  
In Vitro Assays ◽  
Economic Losses ◽  
Maritime Industry ◽  
Marine Biotechnology ◽  
La Paz ◽  
Selection Of

Biofouling causes major economic losses in the maritime industry. In our site study, the Bay of La Paz (Gulf of California), biofouling on immersed structures is a major problem and is treated mostly with copper-based antifouling paints. Due to the known environmental effect of such treatments, the search for environmentally friendly alternatives in this zone of high biodiversity is a priority to ensure the conservation and protection of species. The aim of this work was to link chemical ecology to marine biotechnology: indeed, the natural defense of macroalgae and sponge was evaluated against biofoulers (biofilm and macrofoulers) from the same geographical zone, and some coatings formulation was done for field assays. Our approach combines in vitro and field bioassays to ensure the selection of the best AF agent prospects. The 1st step consisted of the selection of macroalgae (5 species) and sponges (2 species) with surfaces harboring a low level of colonizers; then extracts were prepared and assayed for toxicity against Artemia, activity towards key marine bacteria involved in biofilm formation in the Bay of La Paz, and the potency to inhibit adhesion of macroorganisms (phenoloxidase assays). The most active and non-toxic extracts were further studied for biofouling activity in the adhesion of the bacteria involved in biofilm formation and through incorporation in marine coatings which were immersed in La Paz Bay during 40 days. In vitro assays demonstrated that extracts of Laurencia gardneri, Sargassum horridum (macroalgae), Haliclona caerulea and Ircinia sp. (sponges) were the most promising. The field test results were of high interest as the best formulation were composed of extracts of H. caerulea and S. horridum and led to a reduction of 32% of biofouling compared with the control.

scholarly journals Engraftment after infusion of CD34+ marrow cells in patients with breast cancer or neuroblastoma

Blood ◽  
1991 ◽  
Vol 77 (8) ◽  
pp. 1717-1722 ◽  
Author(s):  
RJ Berenson ◽  
WI Bensinger ◽  
RS Hill ◽  
RG Andrews ◽  
J Garcia-Lopez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stage Iv ◽  
In Vitro Assays ◽  
Hematopoietic Progenitors ◽  
Cd34 Antigen ◽  
Stage Iv Breast Cancer ◽  
Cd34 Cells ◽  
Selection Of ◽  
Marrow Cells

Abstract The CD34 antigen is expressed by 1% to 4% of human and baboon marrow cells, including virtually all hematopoietic progenitors detectable by in vitro assays. Previous work from our laboratory has shown that CD34+ marrow cells can engraft lethally irradiated baboons. Because the CD34 antigen has not been detected on most solid tumors, positive selection of CD34+ cells may be used to provide marrow cells capable of engraftment, but depleted of tumor cells. In seven patients with stage IV breast cancer and two patients with stage IV neuroblastoma, 2.5 to 17.5 x 10(9) marrow cells were separated by immunoadsorption with the anti-CD34 antibody 12–8 and 50 to 260 x 10(6) positively selected cells were recovered that were 64 +/- 16% (range 35% to 92%) CD34+. The patients received 1.0 to 5.2 x 10(6) CD34-enriched cells/kg after marrow ablative therapy. Six patients engrafted, achieving granulocyte counts of greater than 500/mm3 at 34 +/- 10 (range 21 to 47) days and platelets counts of greater than 20,000/mm3 at 46 +/- 14 (range 28 to 66) days posttransplant. Five of these patients showed durable engraftment until the time of death 82 to 386 days posttransplant. One patient failed to sustain engraftment associated with metastatic marrow disease. Three patients died at days 14, 14, and 17 posttransplant, two of whom had evidence of early engraftment. These studies suggest that CD34+ marrow cells are capable of reconstituting hematopoiesis in humans.

scholarly journals Enterotoxins production, biofilm formation and antimicrobial resistance of Staphylococcus aureus strains isolated from refrigerated raw cow milk

2019 ◽  
Vol 42 ◽  
pp. e45231
Author(s):  
Camila Lampugnani ◽  
Maike Taís Maziero Montanhini ◽  
Maria Emilene Martino Campos‐Galvão ◽  
Luis Augusto Nero ◽  
Luciano dos Santos Bersot
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Raw Milk ◽  
Cow Milk ◽  
In Vitro Assays ◽  
Vitro Assay ◽  
Milk Samples ◽  
Adherence Ability

This study aimed to isolate Staphylococcus aureus in refrigerated raw cow milk, and identify the presence of enterotoxin-expression genes, enterotoxin production and adherence ability, and antimicrobial resistance potential of the isolated strains. Fifty raw milk samples obtained in different dairy farms were analyzed for S. aureus and evaluated in the isolates the presence of genes associated with the production of major staphylococcal enterotoxins and biofilm formation. In vitro assays were also performed to evaluate the production of enterotoxins and adherence ability, and the antimicrobial resistance. One half (25/50) of raw milk samples presented coagulase-positive staphylococci and 95.2% of the isolates were confirmed to be S. aureus. Among them, 42.4% were carrying genes for enterotoxins production; however, only one isolate was able to produce enterotoxins. All S. aureus isolates were carrying at least two genes associated with biofilm formation and 95.2% isolates was able to adhere upon the in vitro assay. All isolates demonstrated antimicrobial resistance potential to one or more of the tested antibiotics.

scholarly journals Potential Application of Propolis Extracts to Control the Growth of Stemphylium vesicarium in “Rocha” Pear

2020 ◽  
Vol 10 (6) ◽  
pp. 1990 ◽  
Author(s):  
Marcella Loebler ◽  
Claudia Sánchez ◽  
Elisabete Muchagato Maurício ◽  
Eugénio Diogo ◽  
Mário Santos ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Brown Spot ◽  
In Vitro Assays ◽  
Economic Losses ◽  
Yield Reduction ◽  
Stemphylium Vesicarium ◽  
Spot Disease ◽  
Brown Spot Disease

Stemphylium vesicarium (Wallr.) E. G. Simmons is the pathogen responsible of brown spot disease in pear and has become one of the main concerns for European pear producers. In Portugal, S. vesicarium is responsible for significant yield reduction and economic losses in “Rocha” pear (Pyrus communis L. cv Rocha) production. Considering the antimicrobial potential of propolis, the high incidence of brown spot in pears and the emergence of fungicides resistance in S. vesicarium, this study aimed to evaluate the potential of Portuguese propolis as an alternative strategy to control brown spot disease in “Rocha” pear. In vitro assays showed that propolis extracts were able to inhibit up to 90% the S. vesicarium mycelial growth. In vivo assays in artificially wounded and inoculated “Rocha” pears showed that, compared to the control, the disease incidence decreased up to 25% and the lesions diameter up to 57%, in fruits treated with propolis. Moreover, propolis seems to be more efficient in reducing the disease incidence when applied after pathogen inoculation (curative assay) than when applied before pathogen inoculation (prophylactic assay). Thus, the results suggest that propolis extracts have potential to be applied as part of an integrated approach for the control of brown spot of pear.

ENHANCEMENT OF POLLEN GERMINATION BY PROMOTIVE FACTORS IN INCOMPATIBLE POLLEN

1999 ◽  
Vol 47 (3) ◽  
pp. 165-168
Author(s):  
Dan Eisikowitch ◽  
Hazel Y. Wetzstein
Keyword(s):  
Pollen Grains ◽  
Commercial Production ◽  
In Vitro Assays ◽  
Viable Seed ◽  
Inhibitory Effects ◽  
Incompatible Pollen ◽  
Elemental Analyses ◽  
Compatible Pollen ◽  
Selection Of

Cultivated and wild almonds are self-incompatible and thus require outcrossing by insect pollinators to produce viable seed. In commercial production, considerable efforts are directed towards placement and selection of cultivars for cross-pollination. However, since honeybees do not distinguish between the different cultivars, stigmas are usually covered by a mixture of both compatible and incompatible pollen. Using in vitro assays, we demonstrated that pollen extracts promoted germination in self pollen with no inhibitory effects observed. Elemental analyses of pollen extracts showed that enhanced levels of Ca, Mg, K, Na, and P were eluted from the grains. From this, we raise the question of possible interaction between compatible and incompatible pollen, and speculate that incompatible pollen grains may support and enhance germination of adjacent compatible pollen.

scholarly journals oxyR, a LysR-Type Regulator Involved in Klebsiella pneumoniae Mucosal and Abiotic Colonization

2009 ◽  
Vol 77 (12) ◽  
pp. 5449-5457 ◽  
Author(s):  
Claire Hennequin ◽  
Christiane Forestier
Keyword(s):  
Gastrointestinal Tract ◽  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Defense Mechanisms ◽  
In Vitro Assays ◽  
Intestinal Epithelial ◽  
Bacterial Transcription ◽  
Host Interaction

ABSTRACT Colonization of the gastrointestinal tract is the first event in Klebsiella pneumoniae nosocomial infections, followed by colonization of the bladder or respiratory tract or entry into the bloodstream. To survive in the host, bacteria must harbor specific traits and overcome multiple stresses. OxyR is a conserved bacterial transcription factor with a key role both in the upregulation of defense mechanisms against oxidative stress and in pathogenesis by enhancing biofilm formation, fimbrial expression, and mucosal colonization. A homolog of oxyR was detected in silico in the K. pneumoniae sequenced genome and amplified from the LM21 wild-type strain. To determine the role of oxyR in K. pneumoniae host-interaction processes, an oxyR isogenic mutant was constructed, and its behavior was assessed. At concentrations lower than 107 ml−1, oxyR-deficient organisms were easily killed by micromolar concentrations of H2O2 and exhibited typical aerobic phenotypes. The oxyR mutant was impaired in biofilm formation and types 1 and 3 fimbrial gene expression. In addition, the oxyR mutant was unable to colonize the murine gastrointestinal tract, and in vitro assays showed that it was defective in adhesion to Int-407 and HT-29 intestinal epithelial cells. The behavior of the oxyR mutant was also determined under hostile conditions, reproducing stresses encountered in the gastrointestinal environment: deletion of oxyR resulted in higher sensitivity to bile and acid stresses but not to osmotic stress. These results show the pleiotropic role of oxyR in K. pneumoniae gastrointestinal colonization.

scholarly journals ALS3 Expression as an Indicator for Candida albicans Biofilm Formation and Drug Resistance

2021 ◽  
Vol 12 ◽  
Author(s):  
Keke Deng ◽  
Wei Jiang ◽  
Yanyu Jiang ◽  
Qi Deng ◽  
Jinzhong Cao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Antifungal Agents ◽  
Early Prevention ◽  
Therapy Failure ◽  
Prevention And Treatment ◽  
Selection Of ◽  
Prevention And Therapy

Resistance caused by the formation of the Candida albicans (C. albicans) biofilm is one of the main reasons for antifungal therapy failure. Thus, it is important to find indicators that predict C. albicans biofilm formation to provide evidence for the early prevention and treatment of the C. albicans biofilms. In this study, C. albicans samples were selected from C. albicans septicemia that were sensitive to common antifungal agents. It was found that the agglutinin-like sequence 3 (ALS3) gene was differentially expressed in free, antifungal, drug-sensitive C. albicans. The average ALS3 gene expression was higher in the C. albicans strains with biofilm formation than that in the C. albicans strains without biofilm formation. Then, it was further confirmed that the rate of biofilm formation was higher in the high ALS3 gene expression group than that in the low ALS3 gene expression group. It was found that C. albicans with biofilm formation was more resistant to fluconazole, voriconazole, and itraconazole. However, it maintained its sensitivity to caspofungin and micafungin in vitro and in mice. Further experiments regarding the prevention of C. albicans biofilm formation were performed in mice, in which only caspofungin and micafungin prevented C. albicans biofilm formation. These results suggest that the expression level of ALS3 in C. albicans may be used as an indicator to determine whether C. albicans will form biofilms. The results also show that the biofilm formation of C. albicans remained sensitive to caspofungin and micafungin, which may help to guide the selection of clinical antifungal agents for prevention and therapy.

scholarly journals "Cara inchada" of cattle, an infectious, apparently soil antibiotics-dependant periodontitis in Brazil

2000 ◽  
Vol 20 (2) ◽  
pp. 47-64 ◽  
Author(s):  
Jürgen Döbereiner ◽  
Iveraldo S. Dutra ◽  
Ivan V. Rosa ◽  
Hans Blobel
Keyword(s):  
Recent Observation ◽  
Oral Treatment ◽  
In Vitro Assays ◽  
Economic Losses ◽  
Genus Streptomyces ◽  
Periodontal Tissues ◽  
Subinhibitory Concentrations ◽  
1960S And 1970S ◽  
Determinant Factor

The objective of this review on the investigation of "cara inchada" in cattle (CI), pursued over the last 30 years, was to elucidate the pathogenicity of the disease and come to proper conclusions on its etiology. CI has been widely considered to be of nutritional origin, caused primarily by mineral deficiency or imbalance. However, the disease consists of a rapidly progressive periodontitis, affecting the periodontal tissues at the level of the premolars and molars during the period of tooth eruption generally starting in young calves. The disease led to great economic losses for farmers in central-western Brazil, after the occupation of new land for cattle raising in the 1960s and 1970s. The lateral enlargement of the maxillary bones of affected calves gave the disease the popular name of "cara inchada", i.e., swollen or enlarged face. The enlargement was found to be due to a chronic ossifying periostitis resulting from the purulent alveolitis of CI. Black-pigmented non-saccharolytic Bacteroides melaninogenicus, always together with Actinomyces (Corynebacterium) pyogenes, were isolated in large numbers from the periodontal lesions. B. melaninogenicus could be isolated in small numbers also from the marginal gingiva of a few healthy calves maintained on CI-free farms. "In vitro"-assays showed that streptomycin and actinomycin, as well as the supernatants of cultivates of actinomycetes from soils of CI-prone farms, applied in subinhibitory concentrations to the bacteria tested, enhanced significantly (up to 10 times) the adherence of the black-pigmented B.melaninogenicus to epithelial cells of the bovine gingiva. The antibiotics are apparently produced in large quantities by the increased number of soil actinomycetes, including the genus Streptomyces, that develop when soil microflora are modified by cultivating virgin forest or "Cerrado" (tree-savanna) for the first time for cattle grazing. The epidemiology of CI now provides strong evidence that the ingestion with the forage of such antibiotics could possibly be an important determinant factor for the onset and development of this infectious periodontitis. The antibiotic enhanced adherence of B.melaninogenicus to the sulcus-epithelium of the marginal gingiva, is thought to allow it to colonize, form a plaque and become pathogenic. There is experimental evidence that this determinant factor for the development of the periodontitis is present also in the milk of the mothers of CI-diseased calves. It has been shown that the bacteria isolated from the periodontal CI-lesions produce enzymes and endotoxins capable of destroying the periodontal tissues. The epidemiology of CI, with its decline in incidence and its disappearance after several years, could be explained by the fact that the former equilibrium of the microflora of the once undisturbed virgin soil has been reached again and that the number of antibiotic producing actinomycetes has been anew reduced. By this reasoning and all the data available, CI should be considered as a multifactorial infectious disease, caused primarily by the anaerobic black-pigmented non-saccharolytic Bacteroides melaninogenicus, always together with the micro-anaerobic Actinomyces pyogenes. Accordingly, the onset and development of the infectious periodontitis is apparently determined by ingestion with the forage of subinhibitory concentrations of antibiotics produced in recently cultivated virgin soils. This hypothesis is supported by the recent observation of renewed outbreaks of CI-periodontitis in former CI-prone areas, following fresh cultivation after many years. The infectious nature of CI is confirmed by trials in which virginiamycin was used efficiently for the oral treatment of CI-diseased cattle. Previously it has been shown, that spiramycin and virginiamycin, used as additives in mineral supplements, prevented CI-periodontitis.

scholarly journals Point Mutations and Cytochrome P450 Can Contribute to Resistance to ACCase-Inhibiting Herbicides in Three Phalaris Species

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1703
Author(s):  
José G. Vázquez-García ◽  
Joel Torra ◽  
Candelario Palma-Bautista ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado
Keyword(s):  
Point Mutations ◽  
Resistance Mechanisms ◽  
Target Site ◽  
In Vitro Assays ◽  
Cross Resistance ◽  
Northern Iran ◽  
Target Site Resistance ◽  
Acetyl Coenzyme A Carboxylase ◽  
Selection Of

Species of Phalaris have historically been controlled by acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides; however, overreliance on herbicides with this mechanism of action has resulted in the selection of resistant biotypes. The resistance to ACCase-inhibiting herbicides was characterized in Phalaris brachystachys, Phalaris minor, and Phalaris paradoxa samples collected from winter wheat fields in northern Iran. Three resistant (R) biotypes, one of each Phalaris species, presented high cross-resistance levels to diclofop-methyl, cycloxydim, and pinoxaden, which belong to the chemical families of aryloxyphenoxypropionates (FOPs), cyclohexanediones (DIMs), and phenylpyrazolines (DENs), respectively. The metabolism of 14C-diclofop-methyl contributed to the resistance of the P. brachystachys R biotype, while no evidence of herbicide metabolism was found in P. minor or P. paradoxa. ACCase in vitro assays showed that the target sites were very sensitive to FOP, DIM, and DEN herbicides in the S biotypes of the three species, while the R Phalaris spp. biotypes presented different levels of resistance to these herbicides. ACCase gene sequencing confirmed that cross-resistance in Phalaris species was conferred by specific point mutations. Resistance in the P. brachystachys R biotype was due to target site and non-target-site resistance mechanisms, while in P. minor and P. paradoxa, only an altered target site was found.

scholarly journals In silico ADME in drug design – enhancing the impact

ADMET & DMPK ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 15 ◽  
Author(s):  
Susanne Winiwarter ◽  
Ernst Ahlberg ◽  
Edmund Watson ◽  
Ioana Oprisiu ◽  
Mickael Mogemark ◽  
...  
Keyword(s):  
In Silico ◽  
In Vitro Assays ◽  
Lead Compounds ◽  
Human Dose ◽  
Pharmacokinetic Properties ◽  
In Silico Predictions ◽  
In Silico Models ◽  
The Impact ◽  
Selection Of

<p>Each year the pharmaceutical industry makes thousands of compounds, many of which do not meet the desired efficacy or pharmacokinetic properties, describing the absorption, distribution, metabolism and excretion (ADME) behavior. Parameters such as lipophilicity, solubility and metabolic stability can be measured in high throughput in vitro assays. However, a compound needs to be synthesized in order to be tested. In silico models for these endpoints exist, although with varying quality. Such models can be used before synthesis and, together with a potency estimation, influence the decision to make a compound. In practice, it appears that often only one or two predicted properties are considered prior to synthesis, usually including a prediction of lipophilicity. While it is important to use all information when deciding which compound to make, it is somewhat challenging to combine multiple predictions unambiguously. This work investigates the possibility of combining in silico ADME predictions to define the minimum required potency for a specified human dose with sufficient confidence. Using a set of drug discovery compounds,in silico predictions were utilized to compare the relative ranking based on minimum potency calculation with the outcomes from the selection of lead compounds. The approach was also tested on a set of marketed drugs and the influence of the input parameters investigated.</p>

A Role for Secreted Immune Effectors in Microbial Biofilm Formation Revealed by Simple In Vitro Assays

2021 ◽  
pp. 127-140
Author(s):  
Assunta Liberti ◽  
Brittany A. Leigh ◽  
Zachary Graham ◽  
Ojas Natarajan ◽  
Larry J. Dishaw
Keyword(s):  
Biofilm Formation ◽  
In Vitro Assays ◽  
Microbial Biofilm
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