scholarly journals Evaluating the Effects of Chlortetracycline on the Proliferation of Antibiotic-Resistant Bacteria in a Simulated River Water Ecosystem

2007 ◽  
Vol 73 (17) ◽  
pp. 5421-5425 ◽  
Author(s):  
Jeannette Muñoz-Aguayo ◽  
Kevin S. Lang ◽  
Timothy M. LaPara ◽  
Gerardo González ◽  
Randall S. Singer
Keyword(s):  
River Water ◽  
Biological Activities ◽  
Aerobic Bacteria ◽  
Resistant Bacteria ◽  
Bacterial Populations ◽  
Bacterial Colony ◽  
Water Ecosystem ◽  
Low Levels ◽  
And Control

ABSTRACT Antibiotics and antibiotic metabolites have been found in the environment, but the biological activities of these compounds are uncertain, especially given the low levels that are typically detected in the environment. The objective of this study was to estimate the selection potential of chlortetracycline (CTC) on the antibiotic resistance of aerobic bacterial populations in a simulated river water ecosystem. Six replicates of a 10-day experiment using river water in continuous flow chemostat systems were conducted. Each replicate used three chemostats, one serving as a control to which no antibiotic was added and the other two receiving low and high doses of CTC (8 μg/liter and 800 μg/liter, respectively). The addition of CTC to the chemostats did not impact the overall level of cultivable aerobic bacteria (P = 0.51). The high-CTC chemostat had significantly higher tetracycline-resistant bacterial colony counts than both the low-CTC and the control chemostats (P < 0.035). The differences in resistance between the low-CTC and control chemostats were highly nonsignificant (P = 0.779). In general a greater diversity of tet resistance genes was detected in the high-CTC chemostat and with a greater frequency than in the low-CTC and control chemostats. Low levels of CTC in this in vitro experiment did not select for increased levels of tetracycline resistance among cultivable aerobic bacteria. This finding should not be equated with the absence of environmental risk, however. Low concentrations of antibiotics in the environment may select for resistant bacterial populations once they are concentrated in sediments or other locations.

scholarly journals The Multifunctional Sactipeptide Ruminococcin C1 Displays Potent Antibacterial Activity In Vivo as Well as Other Beneficial Properties for Human Health

2021 ◽  
Vol 22 (6) ◽  
pp. 3253
Author(s):  
Clarisse Roblin ◽  
Steve Chiumento ◽  
Cédric Jacqueline ◽  
Eric Pinloche ◽  
Cendrine Nicoletti ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Human Health ◽  
Biological Activities ◽  
Resistant Bacteria ◽  
Modified Peptides ◽  
The 1960S ◽  
Conventional Antibiotics ◽  
Clinical Potential

The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest.

Reduction of Bacteria on Pork Carcasses Associated with Chilling Method

2003 ◽  
Vol 66 (6) ◽  
pp. 1019-1024 ◽  
Author(s):  
V. P. CHANG ◽  
E. W. MILLS ◽  
C. N. CUTTER
Keyword(s):  
Salmonella Typhimurium ◽  
Meat Products ◽  
Microbial Populations ◽  
Aerobic Bacteria ◽  
Campylobacter Coli ◽  
Test Results ◽  
Bacterial Populations ◽  
Layer Method ◽  
Agar Layer ◽  
Low Levels

In addition to reducing the temperature of pork carcasses immediately after slaughter and before fabrication, blast chilling (snap chill) or conventional chilling can reduce bacterial populations associated with fresh meats. However, there is little information on bacteria survival resulting from the freeze or chill injury of meat products. In this study, porcine fecal slurries with and without pathogens (Listeria monocytogenes, Salmonella Typhimurium, and Campylobacter coli) were inoculated onto skin-on and skin-off pork surfaces and subjected to industry-specific blast or conventional chilling conditions. A thin agar layer method was used for the recovery of freeze- or chill-injured cells. Test results indicated that there were no statistically significant (P &gt; 0.05) differences between blast and conventional chilling treatments with respect to the reduction of high and low inoculation levels of mesophilic aerobic bacteria, total coliforms, or Escherichia coli on either skin-on or skin-off surfaces. Chilling treatments did not differ significantly (P &gt; 0.05) with respect to their ability to reduce low (3 log10 CFU/cm2) levels of L. monocytogenes and Salmonella Typhimurium. However, C. coli was reduced to undetectable levels, even after enrichment, on pork surfaces inoculated with low levels (3 log10 CFU/cm2) and subjected to blast chilling. Blast and conventional chilling treatments were more effective against all pathogenic bacterial populations when pork surfaces where inoculated at high levels (5 log10 CFU/cm2). The effects of chilling techniques on microbial populations could provide pork processors with an additional intervention for pork slaughter or information to modify and/or improve the chilling process. The information obtained from this study has the potential to serve as a means of producing a microbiologically safer product.

Microwave-Assisted One Pot Three-Component Synthesis of Novel Bioactive Thiazolyl-pyridazinediones As Potential Antimicrobial Agents against Antibiotic-Resistant Bacteria

2020 ◽  
Author(s):  
Saraa Abu-Melha ◽  
Sobhi Gomha ◽  
Amr Abouzid ◽  
Mastoura Edrees ◽  
Ahmed Abo Dena ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Biological Activities ◽  
Docking Studies ◽  
Resistant Bacteria ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Antibiotic Resistant ◽  
Naturally Occurring ◽  
High Efficient

Abstract Novel 2-thiazolyl-pyridazinedione derivatives were prepared via multicomponent synthesis under microwave irradiation as ecofriendly energy source and using the eco-friendly naturally occurring chitosan basic catalyst with high/efficient yields and short reaction time. All the prepared compounds were fully characterized by spectroscopic methods, and their in-vitro biological activities were investigated. The obtained results were compared with those of standard antibacterial/antifungal agents. DFT calculations and molecular docking studies were used to investigate the electronic properties and molecular interactions with specific microbial receptors.

Multispecific antibodies targeting CD38 show potent tumor-specific cytotoxicity.

2018 ◽  
Vol 36 (5_suppl) ◽  
pp. 57-57 ◽  
Author(s):  
Shelley Force Aldred ◽  
Andrew Boudreau ◽  
Ben Buelow ◽  
Starlynn Clarke ◽  
Kevin Dang ◽  
...  
Keyword(s):  
Biological Activities ◽  
Building Blocks ◽  
In Vitro Models ◽  
Cytotoxic Effects ◽  
Antibody Therapeutics ◽  
T Cell Lymphomas ◽  
Single Antigen ◽  
Specific Cytotoxicity ◽  
Low Levels

57 Background: Multivalent antibodies targeting either CD38 alone or CD38 in conjunction with PD-L1 may yield therapeutics with superior biological activities and provide benefit for treating malignancies expressing low levels of CD38 (MCL, NHL, T cell lymphomas and Daratumumab refractory MM). Multivalent, multispecific antibodies kill CD38low cells through a variety of mechanisms including stronger and more specific engagement of CD38. Potent and directed immune checkpoint inhibition is realized by adding an anti-PD-L1 binding domain. Teneobio’s discovery platform utilizes VH domains (UniDabs) of fully human heavy chain antibodies (UniAbs) to develop bi-, tri-, and tetravalent antibodies. Methods: Individual UniDabs targeting CD38 and PDL1 were identified using our unique sequence-based discovery platform and high-throughput lead evaluation pipeline (TeneoSeek). This robust screening workflow enables evaluation of a large diversity of natural fully human antibodies, targeting multiple epitopes on a single antigen and uncovering important sequence activity relationships. UniDabs from transgenic rats are ideal building blocks for the generation of potent and highly manufacturable multivalent antibody therapeutics. Results: We have identified UniDabs that efficiently block PD-1/PD-L1 interaction as well as additional UniDabs that bind to five different functional epitopes on human CD38. Using different combinations and arrangements of UniDabs, a variety of multivalent antibodies were constructed and evaluated in in vitro models. Specific combinations of UniDabs show more potent cytotoxic effects than Daratumumab for multiple mechanisms including CDC and direct apoptosis. Conclusions: Data from a range of assay types show that multivalent UniAbs targeting CD38 can be engineered to display superior tumor cell cytotoxicity through multiple mechanisms of action.

scholarly journals Middermal Elastolysis: Dermal Fibroblasts Cooperate with Inflammatory Cells to the Elastolytic Disorder

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Giovanna De Cunto ◽  
Arianna Lamberti ◽  
Maria Margherita de Santi ◽  
Clelia Miracco ◽  
Michele Fimiani ◽  
...  
Keyword(s):  
Inflammatory Cells ◽  
Dermal Fibroblasts ◽  
Reticular Dermis ◽  
Tissue Samples ◽  
Naturally Occurring ◽  
Low Levels ◽  
And Control ◽  
Shed Light

Little is known about the cause and pathophysiology of middermal elastolysis (MDE). In this condition, variable inflammatory infiltrate may be present or not together with loss of elastic fibres in the middermis that spares both papillary and lower reticular dermis. MDE may be a consequence of abnormal extracellular matrix degradation related to an imbalance between elastolytic enzymes released from inflammatory and resident cells and their naturally occurring inhibitors. However, the cause of this imbalance is still an object of investigation. In order to shed light on the role of fibroblasts in MDE, we used fibroblast cultures from MDE and control subjects to evaluate matrix metalloproteinases (MMPs) and their major inhibitor TIMP-1, which in combination with neutrophil or macrophage proteases released in inflamed areas may influence the elastolytic burden. We demonstrate that fibroblasts derived from MDE produce in vitro low levels of TIMP-1, the major inhibitor of MMPs. Elevated levels of MMP-2, MMP-14, and TIMP-2 capable to activate in a cooperative manner pro-MMP-2 are present in MDE tissue samples. Additionally, significant reaction for MMP-1 is present in the same MDE areas. These data all together suggest that ECM changes in MDE are due to cooperation of different cell populations (i.e., inflammatory cells and fibroblasts).

scholarly journals Comparison between Biological Activities of Commercial and Synthesized Carbon Nanotubes by Flame Fragments Deposition Technique

2019 ◽  
Vol 16 (4) ◽  
pp. 0878 ◽  
Author(s):  
Alwindawi Et al.
Keyword(s):  
Carbon Nanotubes ◽  
Standard Sample ◽  
Biological Activities ◽  
Resistant Bacteria ◽  
Liquefied Petroleum Gas ◽  
Standard Samples ◽  
Pharmaceutical Application ◽  
Drug Resistant Bacteria ◽  
Different Types

Carbon nanotubes (CNTs) were synthesized via liquefied petroleum gas (LPG) as precursor using flame fragments deposition (FFD) technique. In vitro, biological activates of carbon nanotubes (CNTs) synthesized by FFD technique were investigated. The physiochemical characterizations of synthesized CNTs are similar to other synthesized CNTs and to the standard sample. Pharmaceutical application of synthesized CNTs was studied via conjugation and adsorption with different types of medicines as promote groups. The conjugation of CNTs was performed by adsorption the drugs such as sulfamethoxazole (SMX) and trimethoprim (TMP) on CNTs depending on physical properties of both bonded parts. The synthesized CNTs almost have the same performance in antibiotic activity compared with standard sample of CNTs (commercial CNTs).The products were effective antibiotic in the treatment as resistant bacteria, may higher concentration of CNTs would have antibacterial activity on multi-drug resistant bacteria such as Acinetobacter and also on resistant E.coli. The bioactivity synthesized and standard samples of CNTs were almost the same against different types of bacteria.

scholarly journals Root Initiation In Mukhikachu (Colocasia Esculenta)As Influenced By IAA And NAA

1970 ◽  
Vol 36 (3) ◽  
pp. 487-494 ◽  
Author(s):  
MKR Bhuiyan ◽  
MJ Hossain ◽  
MS Rahman ◽  
SML Rahman ◽  
MA Sattar
Keyword(s):  
Colocasia Esculenta ◽  
Factorial Experiment ◽  
Lower Percentage ◽  
Root Initiation ◽  
Low Levels ◽  
And Control ◽  
Fresh Surface ◽  
Cambium Zone ◽  
Better Than

In vitro root initiation in Mukhikachu (Colocasia esculenta var. globulifera) was assessed in a factorial experiment using three levels of IAA (0.5, 1.0, and 2.0 mg/l), three levels of NAA (0.5, 1.0, and 2.0 mg/l) and control. Fifty percent intact shoots were used as usual, which was named as normal cut explant and the rest 50 % shoots were cut slantly to expose fresh surface i.e., cambium zone and named as slant cut explant. Low levels of IAA (0.5mg/l) initiated the roots earliest (≈14 DAC) and gave the highest percentage of root (49.71). This treatment also gave the maximum roots/culture (3.63). Root initiation was higher (61.33 %) with slant cut when cultured on a medium containing 0.5 mg/l IAA. The cultures with slant cut end also produced more number of roots and longest roots whereas, the highest root initiation (45.05 %) was given by the treatment 1.0 mg/l NAA, but 2.0 mg/I NAA gave lower percentage of roots (39.89).The maximum number of roots/culture was also obtained by 1.0 mg/l NAA. Slant cut explant performed better regarding root initiation (%), number of roots/culture and length of roots. In this experiment, slant cut explant performed better than that of normal cut and either IAA (0.05 mg/l) or NAA (1.0 mg/l) might be used for root initiation in Mukhikachu. Keywords: Root initiation; Colocasia; IAA; NAA. DOI: http://dx.doi.org/10.3329/bjar.v36i3.9276 BJAR 2011; 36(3): 487-494

Overexpression of SPARC in stably transfected F9 cells mediates attachment and spreading in Ca2+-deficient medium

1992 ◽  
Vol 70 (12) ◽  
pp. 1368-1379 ◽  
Author(s):  
Elizabeth A. Everitt ◽  
E. Helene Sage
Keyword(s):  
Extracellular Matrix ◽  
Cell Lines ◽  
Cell Shape ◽  
F9 Cells ◽  
Deficient Medium ◽  
Enhanced Expression ◽  
Low Levels ◽  
And Control ◽  
Sparc Expression

The Ca2+-binding protein SPARC is one of a group of proteins that function in vitro to promote the rounding of cells. To assess whether the modulation of cell shape by SPARC is affected by extracellular Ca2+, we used F9 cell lines that had been stably transfected with sense or antisense SPARC DNA. Sense-transfected (S) lines that overexpress SPARC are aggregated and rounded, whereas antisense (AS) lines that express low levels of the protein are flat and spread. We tested whether the cell lines would exhibit these altered morphologies in Ca2+ -deficient media. When cultured under these conditions, S lines attached and spread, whereas AS lines attached but remained round, with no subsequent spreading. Addition of CaCl2 or purified SPARC to the Ca2+-deficient medium resulted in spreading of the AS and control lines and a reappearance of the altered morphologies. Expression of the Ca2+-binding cadherin uvomorulin by the cell lines correlated with neither their morphology nor their level of SPARC expression. We conclude that the altered phenotypes of the transected lines reflect, in part, the concentration of extracellular Ca2+ and that the spreading exhibited by the S lines under Ca2+-deficient conditions is directly related to their enhanced expression of SPARC. SPARC might, therefore, mediate interactions between cells and matrix that are permissive for adhesion when levels of extracellular Ca2+ are diminished.Key words: adhesion, cell shape, extracellular matrix, SPARC.

scholarly journals In Vitro Human Metabolism and Inhibition Potency of Verbascoside for CYP Enzymes

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2191 ◽  
Author(s):  
Anna-Mari Reid ◽  
Risto Juvonen ◽  
Pasi Huuskonen ◽  
Marko Lehtonen ◽  
Markku Pasanen ◽  
...  
Keyword(s):  
Biological Activities ◽  
Tuberculosis Treatment ◽  
Inhibitory Potency ◽  
Cyp Enzymes ◽  
Hepatic Microsomes ◽  
Ic50 Values ◽  
Low Levels ◽  
Plant Families ◽  
Inhibition Potency

Verbascoside is found in many medicinal plant families such as Verbenaceae. Important biological activities have been ascribed to verbascoside. Investigated in this study is the potential of verbascoside as an adjuvant during tuberculosis treatment. The present study reports on the in vitro metabolism in human hepatic microsomes and cytosol incubations as well as the presence and quantity of verbascoside within Lippia scaberrima. Additionally, studied are the inhibitory properties on human hepatic CYP enzymes together with antioxidant and cytotoxic properties. The results yielded no metabolites in the hydrolysis or cytochrome P450 (CYP) oxidation incubations. However, five different methylated conjugates of verbascoside could be found in S-adenosylmethionine incubation, three different sulphate conjugates with 3′-phosphoadenosine 5′-phosphosulfate (PAPS) incubation with human liver samples, and very low levels of glucuronide metabolites after incubation with recombinant human uridine 5’-diphospho-glucuronosyltransferase (UGT) 1A7, UGT1A8, and UGT1A10. Additionally, verbascoside showed weak inhibitory potency against CYP1A2 and CYP1B1 with IC50 values of 83 µM and 86 µM, respectively. Potent antioxidant and low cytotoxic potential were observed. Based on these data, verbascoside does not possess any clinically relevant CYP-mediated interaction potential, but it has effective biological activity. Therefore, verbascoside could be considered as a lead compound for further drug development and as an adjuvant during tuberculosis treatment.

scholarly journals Antibiotic resistance in surface waters from a coastal lagoon of Southern Brazil under the impact of anthropogenic activities

2019 ◽  
Vol 14 (5) ◽  
pp. 1
Author(s):  
Belize Leite ◽  
Magda Antunes de Chaves ◽  
Athos Aramis Thopor Nunes ◽  
Louise Jank ◽  
Gertrudes Corção
Keyword(s):  
Antibiotic Resistance ◽  
Coastal Lagoon ◽  
Anthropogenic Activities ◽  
Class I ◽  
Systematic Evaluation ◽  
Resistant Bacteria ◽  
Bacterial Populations ◽  
Antibiotic Resistant ◽  
The Impact

Wastes arising from human activities can reach water bodies and contribute significantly to the presence of antibiotic resistant bacterial populations in aquatic environments. The objective of this study was to evaluate the cultivable antibiotic resistant bacterial populations from a coastal lagoon impacted by agriculture and urbanization activities. Water samples were collected in low and peak season and characterized regarding physicochemical variables, microbiological indicators and the presence of antimicrobial residues. In order to analyze the presence of resistant bacterial populations, the samples were grown in the presence of nalidixic acid, ceftazidime, imipenem and tetracycline. Genes associated with β-lactamic resistance (blaCTX-M-like, blaGES-like, blaOXA-51, blaOXA-23-like, blaSHV-like, blaTEM-like and blaSPM-1), class I integron and efflux systems (tetA, tetB, acrA, acrB, tolC, adeA, adeB, adeR, adeS, mexB, mexD, mexF and mexY) were analyzed by conventional in vitro amplification. Although antimicrobials residues were below the detection limit, resistant bacteria and resistance determinants - blaGES, class I integron, adeS, acrA, acrB, tolC, mexB, mexF - were present at almost all points, in both seasons and for all antimicrobials assessed. The high numbers of resistant bacteria counts observed after the antibiotic treatment were positively correlated to the urbanization effects on the Lagoon. Some resistant populations were even higher in the low season samples, indicating the importance of a systematic evaluation of antibiotic resistance on water resources.

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