scholarly journals Antimicrobial and Antibiofilm Activities of 4,5-Dihydro-1H-pyrazole-1-carboximidamide Hydrochloride against Salmonella spp.

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Andressa C. Damim ◽  
Danilo Y. de Albuquerque ◽  
Fabiana G. S. Dantas ◽  
Fernanda Galvão ◽  
Melyssa Negri ◽  
...  

In the present study, the antimicrobial and antibiofilm activities of two 4,5-dihydro-1H-pyrazole-1-carboximidamide hydrochloride, (trifluoromethyl) phenyl-substituted (compound 1) and bromophenyl-substituted (compound 2), were evaluated against four Salmonella spp. serotypes through broth microdilution and biofilm-forming activity. Further, the cytotoxicity of the compounds was evaluated by cell viability assays using cultures of HeLa and Vero cell lines, and the mutagenic potential was assessed by the Ames test. In the broth microdilution test, compound 1 inhibited 90% of the strains tested at the minimum inhibitory concentration of 62.5 μg mL−1. Furthermore, both compounds prevented biofilm formation, with a reduction of up to 5.2 log10. HeLa and Vero cells exhibited 100% viability in the presence of compound 1. In contrast, low cell viability was observed in the presence of 15 µg mL−1 of compound 2. Furthermore, no mutagenic potential was detected at any of the tested concentrations of compound 1.

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1856 ◽  
Author(s):  
Fabiana Gomes da Silva Dantas ◽  
Adriana Araújo de Almeida-Apolonio ◽  
Renata Pires de Araújo ◽  
Lis Regiane Vizolli Favarin ◽  
Pamella Fukuda de Castilho ◽  
...  

The high mortality rate of candidemia and the limited option for the treatment of Candida spp. infection have been driving the search for new molecules with antifungal property. In this context, coordination complexes of metal ions and ligands appear to be important. Therefore, this study aimed to synthesize two new copper(II) complexes with 2-thiouracil and 6-methyl-2-thiouracil ligands and to evaluate their mutagenic potential and antifungal activity against Candida. The complexes were synthesized and characterized by infrared vibrational spectroscopy, CHN elemental analysis, UV-Vis experiments and ESI-HRMS spectrometry studies. The antifungal activity was evaluated by broth microdilution against 21 clinical isolates of Candida species. The mutagenic potential was evaluated by the Ames test. The complexes were Cu(Bipy)Cl2(thiouracil) (Complex 1) and Cu(Bipy)Cl2(6-methylthiouracil) (Complex 2). Complex 1 showed fungicidal and fungistatic activities against all isolates. Furthermore, the Minimum Inhibitory Concentration (MIC) from 31 to 125 µg/mL and inhibition percentage of 9.9% against the biofilms of C. krusei and C. glabrata were demonstrated. At the concentrations tested, complex 1 exhibited no mutagenic potential. Complex 2 and the free ligands exhibited no antifungal activity at the concentrations evaluated. Since complex 1 presented antifungal activity against all the tested isolates and no mutagenic potential, it could be proposed as a potential new drug for anti-Candida therapy.


2020 ◽  
Vol 16 (7) ◽  
pp. 1049-1062
Author(s):  
Balasupramaniam Kirubakari ◽  
Yeng Chen ◽  
Jagat R. Kanwar ◽  
Lai N. Shin ◽  
Sreenivasan Sasidharan

Background: Polyalthia longifolia which originates from India is rich with various useful phytochemicals which are valuable for human health. Accordingly, the current study was conducted to evaluate the combinational antimicrobial activity of P. longifolia Ethyl Acetate Fraction (PLEAF) with ampicillin, antioxidant and cytotoxicity activities. Methods: The evaluation of the synergistic activity of PLEAF fraction and ampicillin against MRSA local isolate was conducted with various antimicrobial assays. Results: The Minimum Inhibitory Concentration (MIC) values of PLEAF fraction (62.5 μg/mL) and ampicillin (5000 μg/mL) were found to decrease to 15.63 μg/mL for PLEAF and 2500 μg/mL for ampicillin respectively in the Fractional Inhibitory Concentration (FIC) assay against the MRSA bacteria. The 2,2-diphenyl1-picrylhydrazyl (DPPH) and nitric oxide free radical scavenging activities showed that PLEAF fraction possessed high antioxidant activity and the combinational of PLEAF fraction and ampicillin exhibited moderate antioxidant activity. The total phenolic content (TPC) of PLEAF was 168.22 ± 0.00407 μg GAE/g of PLEAF fraction. Discussion: henolic compounds might be responsible for the observed antioxidant and antimicrobial activity of PLEAF fraction. In addition, in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity test against Vero cells the PLEAF fraction was proven to be non-toxic (98.14% of cell viability) and the combination of PLEAF fraction and ampicillin treatment against the Vero cells showed an improved cell viability (52.44%) as compared with ampicillin alone in the treated group. Conclusions: The PLEAF fraction works well in combination with ampicillin to kill the MRSA local resistance strain. PLEAF fraction also showed favourable antioxidant activity and improved Vero cell viability in the presence of ampicillin which is an important attribute of PLEAF fraction to be used in the future combinational therapy.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hadiza Aliyu-Amoo ◽  
Hamza Ibrahim Isa ◽  
Emmanuel Mfotie Njoya ◽  
Lyndy Joy McGaw

Abstract Background Terminalia avicennioides Guill and Perr (Combretaceae) is an important West African medicinal plant. The plant is used locally against microbes and parasites in both humans and animals and studies have demonstrated its cytotoxicity potential. Thus, this study was carried out to test the cytotoxic effect of the extracts and fractions of the root of the medicinal plant Terminalia avicennioides Guill and Perr (Combretaceae) in two different cell lines. Methods Methanol, ethanol, 30 % ethanol, hot water and cold water extracts and ethylacetate, hexane, chloroform, butanol and residual water fractions, were evaluated at 1000, 750, 500, 250, 100 and 50 µg/mL concentrations, with doxorubicin as positive control. The cells were incubated with the extracts for 48 h at 37 °C in a 5 % CO2 humidified incubator. The inhibition of cell viability, determined with the methyl blue thiazole tetrazolium bromide (MTT) assay, was used to assess the anti-proliferative effect of the extracts, in normal Vero Monkey kidney and human liver cancer (HepG2) cell lines. Results There was a concentration-dependent inhibition of cell viability in both the HepG2 and Vero cell lines. For HepG2 cells, antiproliferative effect was highest for the hexane fraction (viability ranged from 19.63 ± 1.10 % to 70.30 ± 1.78 % for 1000 and 50 µg/mL, respectively. For Vero cells, the highest antiproliferative effect, at 1000 µg/mL, was with hexane fraction (cell viability 21.37 ± 3.50 %), while at 50 µg/mL the chloroform fraction demonstrated the highest effect (viability of 86.10 ± 1.95 %). Conclusions The extracts and fractions from the root of Terminalia avicennioides have antiproliferative effect on the Vero and HepG2 cell lines tested. However, the extracts and fractions were not more toxic to the HepG2 than to the Vero cells. The cytotoxic effect of stem-bark and leaf extracts could be evaluated in the future to determine its anticancer potential.


2020 ◽  
Vol 26 (24) ◽  
pp. 2807-2816 ◽  
Author(s):  
Yun Su Jang ◽  
Tímea Mosolygó

: Bacteria within biofilms are more resistant to antibiotics and chemical agents than planktonic bacteria in suspension. Treatment of biofilm-associated infections inevitably involves high dosages and prolonged courses of antimicrobial agents; therefore, there is a potential risk of the development of antimicrobial resistance (AMR). Due to the high prevalence of AMR and its association with biofilm formation, investigation of more effective anti-biofilm agents is required. : From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota. : With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 785
Author(s):  
Abubakar Siddique ◽  
Sara Azim ◽  
Amjad Ali ◽  
Saadia Andleeb ◽  
Aitezaz Ahsan ◽  
...  

Salmonellosis caused by non-typhoidal Salmonellaenterica from poultry products is a major public health concern worldwide. This study aimed at estimating the pathogenicity and antimicrobial resistance in S. enterica isolates obtained from poultry birds and their food products from different areas of Pakistan. In total, 95/370 (25.67%) samples from poultry droppings, organs, eggs, and meat were positive for Salmonella. The isolates were further identified through multiplex PCR (mPCR) as Salmonella Typhimurium 14 (14.7%), Salmonella Enteritidis 12 (12.6%), and other Salmonella spp. 69 (72.6%). The phenotypic virulence properties of 95 Salmonella isolates exhibited swimming and/or swarming motility 95 (100%), DNA degrading activity 93 (97.8%), hemolytic activity 92 (96.8%), lipase activity 87 (91.6%), and protease activity 86 (90.5%). The sopE virulence gene known for conferring zoonotic potential was detected in S. Typhimurium (92.8%), S. Enteritidis (100%), and other Salmonella spp. (69.5%). The isolates were further tested against 23 antibiotics (from 10 different antimicrobial groups) and were found resistant against fifteen to twenty-one antibiotics. All isolates showed multiple drug resistance and were found to exhibit a high multiple antibiotic-resistant (MAR) index of 0.62 to 0.91. The strong biofilm formation at 37 °C reflected their potential adherence to intestinal surfaces. There was a significant correlation between antimicrobial resistance and the biofilm formation potential of isolates. The resistance determinant genes found among the isolated strains were blaTEM-1 (59.3%), blaOxA-1 (18%), blaPSE-1 (9.5%), blaCMY-2 (43%), and ampC (8.3%). The detection of zoonotic potential MDR Salmonella in poultry and its associated food products carrying cephalosporin and quinolone resistance genes presents a major threat to the poultry industry and public health.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S391-S391
Author(s):  
Maria M Traczewski ◽  
Denise Beasley ◽  
Amanda Harrington ◽  
Sharon DesJarlais ◽  
Omai Garner ◽  
...  

Abstract Background Updated US FDA/CLSI ciprofloxacin breakpoints were evaluated against data from a multicenter clinical study with Enterobacterales, Salmonella spp. and P. aeruginosa on a MicroScan Dried Gram-negative MIC (MSDGN) Panel. MIC results were compared to results obtained with frozen broth microdilution panels prepared according to CLSI methodology. Methods MSDGN panels were evaluated at three clinical sites by comparing MIC values obtained using the MSDGN panels to MICs utilizing a CLSI broth microdilution reference panel. Data from the combined phases of efficacy and challenge included 803 Enterobacterales, Salmonella spp. and P. aeruginosa clinical isolates tested using the turbidity and Prompt® methods of inoculation. To demonstrate reproducibility, a subset of 12 organisms were tested on MSDGN panels at each site during reproducibility. MSDGN panels were incubated at 35 ± 1ºC and read on the WalkAway System, the autoSCAN-4 instrument, and visually. Read times for the MSDGN panels were at 16-20 hours. Frozen reference panels were prepared and read according to CLSI methodology. FDA and CLSI breakpoints (µg/mL) used for interpretation of MIC results were: Enterobacterales ≤ 0.25 S, 0.5 I, ≥ 1 R; Salmonella spp. ≤ 0.06 S, 0.12-0.5 I, ≥ 1 R; P. aeruginosa ≤ 0.5 S, 1 I, ≥ 2 R. Results Essential and categorical agreement was calculated compared to frozen reference panel results. Results for isolates tested during efficacy and challenge with Prompt inoculation and manual read are as follows: Conclusion Ciprofloxacin MIC results for Enterobacterales, Salmonella spp., and P. aeruginosa obtained with the MSDGN panel correlate well with MICs obtained using frozen reference panels using updated FDA/CLSI interpretive criteria in this multicenter study. * PROMPT® is a registered trademark of 3M Company, St. Paul, MN USA. BEC, the stylized logo and the BEC product and service marks mentioned herein are trademarks or registered trademarks of Beckman Coulter, Inc. in the US and other countries. Disclosures Maria M. Traczewski, BS MT (ASCP), Beckman Coulter (Scientific Research Study Investigator) Denise Beasley, BS, Beckman Coulter (Other Financial or Material Support, Research personnel) Amanda Harrington, PhD, Beckman Coulter (Scientific Research Study Investigator) Sharon DesJarlais, BS, Beckman Coulter (Other Financial or Material Support, Research personnel) Omai Garner, PhD, D(ABMM), Beckman Coulter (Scientific Research Study Investigator) Christine Hastey, PhD, Beckman Coulter (Employee) Regina Brookman, BS, Beckman Coulter (Employee) Zabrina Lockett, MS, Beckman Coulter (Employee) Jennifer Chau, PhD, Beckman Coulter (Employee)


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1704
Author(s):  
Krzysztof Pałka ◽  
Małgorzata Miazga-Karska ◽  
Joanna Pawłat ◽  
Joanna Kleczewska ◽  
Agata Przekora

The aim of this study was to evaluate the effect of modification with liquid rubber on the adhesion to tooth tissues (enamel, dentin), wettability and ability to inhibit bacterial biofilm formation of resin-based dental composites. Two commercial composites (Flow-Art–flow type with 60% ceramic filler and Boston–packable type with 78% ceramic filler; both from Arkona Laboratorium Farmakologii Stomatologicznej, Nasutów, Poland) were modified by addition of 5% by weight (of resin) of a liquid methacrylate-terminated polybutadiene. Results showed that modification of the flow type composite significantly (p < 0.05) increased the shear bond strength values by 17% for enamel and by 33% for dentine. Addition of liquid rubber significantly (p < 0.05) reduced also hydrophilicity of the dental materials since the water contact angle was increased from 81–83° to 87–89°. Interestingly, modified packable type material showed improved antibiofilm activity against Steptococcus mutans and Streptococcus sanguinis (quantitative assay with crystal violet), but also cytotoxicity against eukaryotic cells since cell viability was reduced to 37% as proven in a direct-contact WST-8 test. Introduction of the same modification to the flow type material significantly improved its antibiofilm properties (biofilm reduction by approximately 6% compared to the unmodified material, p < 0.05) without cytotoxic effects against human fibroblasts (cell viability near 100%). Thus, modified flow type composite may be considered as a candidate to be used as restorative material since it exhibits both nontoxicity and antibiofilm properties.


2004 ◽  
Vol 48 (1) ◽  
pp. 151-160 ◽  
Author(s):  
Giovanni Di Bonaventura ◽  
Ilaria Spedicato ◽  
Domenico D'Antonio ◽  
Iole Robuffo ◽  
Raffaele Piccolomini

ABSTRACT We investigated the in vitro effects of seven fluoroquinolones (ciprofloxacin, grepafloxacin, levofloxacin, moxifloxacin, norfloxacin, ofloxacin, and rufloxacin), compared to those of trimethoprim-sulfamethoxazole (SXT) and ceftazidime on total biomass and cell viability of Stenotrophomonas maltophilia biofilm. S. maltophilia attached rapidly to polystyrene, within 2 h of incubation, and then biofilm formation increased over time, reaching maximum growth at 24 h. In the presence of fluoroquinolones at one-half and one-fourth the MIC, biofilm biomass was significantly (P < 0.01) reduced to 55 to 70% and 66 to 76% of original mass, respectively. Ceftazidime and SXT did not exert any activity. Biofilm bacterial viability was significantly reduced by all antibiotics tested at one-half the MIC. At one-fourth the MIC all antibiotics, except levofloxacin, significantly reduced viability. Treatment of preformed biofilms with bactericidal concentrations (500, 100, and 50 μg/ml) of all fluoroquinolones caused, except for norfloxacin, significant reduction of biofilm biomass to 29.5 to 78.8, 64.1 to 83.6, and 70.5 to 82.8% of original mass, respectively. SXT exerted significant activity at 500 μg/ml only. Ceftazidime was completely inactive. Rufloxacin exhibited the highest activity on preformed biofilm viability, significantly decreasing viable counts by 0.6, 5.4, and 17.1% at 500, 100, and 50 μg/ml, respectively. Our results show that (i) subinhibitory (one-half and one-fourth the MIC) concentrations of fluoroquinolones inhibit adherence of S. maltophilia to polystyrene and (ii) clinically achievable concentrations (50 and 100 μg/ml) of rufloxacin are able to eradicate preformed S. maltophilia biofilm.


Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2013 ◽  
Author(s):  
Ricardo Murcia ◽  
Sandra Leal ◽  
Martha Roa ◽  
Edgar Nagles ◽  
Alvaro Muñoz-Castro ◽  
...  

In this work, six complexes (2–7) of Cr(III) and Co(II) transition metals with triazole ligands were synthesized and characterized. In addition, a new ligand, 3,5-bis(1,2,4-triazol-1-ylmethyl)toluene (1), was synthesized and full characterized. The complexes were obtained as air-stable solids and characterized by melting point, electrical conductivity, thermogravimetric analysis, and Raman, infrared and ultraviolet/visible spectroscopy. The analyses and spectral data showed that complexes 3–7 had 1:1 (M:L) stoichiometries and octahedral geometries, while 2 had a 1:2 (M:L) ratio, which was supported by DFT calculations. The complexes and their respective ligands were evaluated against bacterial and fungal strains with clinical relevance. All the complexes showed higher antibacterial and antifungal activities than the free ligands. The complexes were more active against fungi than against bacteria. The activities of the chromium complexes against Candida tropicalis are of great interest, as they showed minimum inhibitory concentration 50 (MIC50) values between 7.8 and 15.6 μg mL−1. Complexes 5 and 6 showed little effect on Vero cells, indicating that they are not cytotoxic. These results can provide an important platform for the design of new compounds with antibacterial and antifungal activities.


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