scholarly journals In Vitro Evaluation of the Therapeutic Potential of Phage VA7 against Enterotoxigenic Bacteroides fragilis Infection

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2044
Author(s):  
Nata Bakuradze ◽  
Maya Merabishvili ◽  
Khatuna Makalatia ◽  
Elene Kakabadze ◽  
Nino Grdzelishvili ◽  
...  

Since the beginning of the 20th century, bacteriophages (phages), i.e., viruses that infect bacteria, have been used as antimicrobial agents for treating various infections. Phage preparations targeting a number of bacterial pathogens are still in use in the post-Soviet states and are experiencing a revival in the Western world. However, phages have never been used to treat diseases caused by Bacteroides fragilis, the leading agent cultured in anaerobic abscesses and postoperative peritonitis. Enterotoxin-producing strains of B. fragilis have been associated with the development of inflammatory diarrhea and colorectal carcinoma. In this study, we evaluated the molecular biosafety and antimicrobial properties of novel phage species vB_BfrS_VA7 (VA7) lysate, as well as its impact on cytokine IL-8 production in an enterotoxigenic B. fragilis (ETBF)-infected colonic epithelial cell (CEC) culture model. Compared to untreated infected cells, the addition of phage VA7 to ETBF-infected CECs led to significantly reduced bacterial counts and IL-8 levels. This in vitro study confirms the potential of phage VA7 as an antibacterial agent for use in prophylaxis or in the treatment of B. fragilis infections and associated colorectal carcinoma.

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


1999 ◽  
Vol 43 (9) ◽  
pp. 2251-2255 ◽  
Author(s):  
M. L. Peterson ◽  
L. B. Hovde ◽  
D. H. Wright ◽  
A. D. Hoang ◽  
J. K. Raddatz ◽  
...  

ABSTRACT In vitro pharmacodynamic studies investigating the antimicrobial properties of five fluoroquinolones, (trovafloxacin, sparfloxacin, clinafloxacin, levofloxacin, and ciprofloxacin) againstBacteroides fragilis ATCC 23745 were conducted. The times required to reduce the viable counts by 3 log units were as follows: clinafloxacin, 2.9 h; levofloxacin, 4.6 h; trovafloxacin, 6 h; and sparfloxacin, 10 h. Exposure to ciprofloxacin did not achieve a 3-log decrease in viable counts. The susceptibility ofB. fragilis was determined both prior to exposure and following 24 h of exposure to each of the five fluoroquinolones tested. The MICs of clinafloxacin, levofloxacin, trovafloxacin, sparfloxacin, ciprofloxacin, metronidazole, cefoxitin, chloramphenicol, and clindamycin were determined by the broth microdilution method. The MICs for B. fragilis preexposure were as follows: clinafloxacin, 0.25 μg/ml; trovafloxacin, 0.5 μg/ml; sparfloxacin, 2 μg/ml; levofloxacin, 2 μg/ml; and ciprofloxacin, 8 μg/ml. Similar pre- and postexposure MICs were obtained for cultures exposed to trovafloxacin, clinafloxacin, levofloxacin, and ciprofloxacin. However, following 24 h of exposure to sparfloxacin, a fluoroquinolone-resistant strain emerged. The MICs for this strain were as follows: clinafloxacin, 1 μg/ml; trovafloxacin, 4 μg/ml; sparfloxacin, 16 μg/ml; levofloxacin, 16 μg/ml; and ciprofloxacin, 32 μg/ml. No changes in the susceptibility of B. fragilispre- and postexposure to sparfloxacin were noted for metronidazole (MIC, 1 μg/ml), cefoxitin (MIC, 4 μg/ml), chloramphenicol (MIC, 4 μg/ml), and clindamycin (MIC, 0.06 μg/ml). Resistance remained stable as the organism was passaged on antibiotic-free agar for 10 consecutive days. Mutant B. fragilis strains with decreased susceptibility to clinafloxacin, trovafloxacin, sparfloxacin, levofloxacin, and ciprofloxacin were selected on brucella blood agar containing 8× the MIC of levofloxacin at a frequencies of 6.4 × 10−9, 4× the MICs of trovafloxacin and sparfloxacin at frequencies of 2.2 × 10−9 and 3.3 × 10−10, respectively, and 2× the MIC of clinafloxacin at a frequency of 5.5 × 10−11; no mutants were selected with ciprofloxacin. The susceptibilities of strains to trovafloxacin, levofloxacin, clinafloxacin, sparfloxacin, and ciprofloxacin before and after exposure to sparfloxacin were modestly affected by the presence of reserpine (20 μg/ml), an inhibitor of antibiotic efflux. The mechanism of fluoroquinolone resistance is being explored, but it is unlikely to be efflux due to a lack of cross-resistance to unrelated antimicrobial agents and to the fact that the MICs for strains before and after exposure to sparfloxacin are minimally affected by reserpine.


Author(s):  
. Isha ◽  
Neetu Sachan

Aims: To synthesize thiazole derivatives and evaluate their therapeutic potential to continue our quest for new antibacterial and antioxidant drugs. Place and Duration of Study: Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, between January 2021 and July 2021. Methodology: The target compounds in this investigation were synthesized in the search for new molecules having antioxidant and antimicrobial activity. Physicochemical and spectroanalytical studies validated the derivatives molecular structures. Antioxidant and antimicrobial properties of the synthesized molecules were evaluated in vitro using the DPPH and tube dilution methods, respectively. Results: The majority of the synthesized derivatives displayed antioxidant and antimicrobial activity. The efficacy of the derivatives varied based upon the substituent. Compound 7c exhibited significant antioxidant and antibacterial activity, according to the results of the study. Conclusion: Our results showed the antioxidant and antibacterial properties of novel thiazole compounds, implying the probability of their utilization in the development of new therapeutics.


Author(s):  
Mayson H. Alkhatib ◽  
Dalal Al-Saedi ◽  
Wadiah S. Backer

The combination of anticancer drugs in nanoparticles has great potential as a promising strategy to maximize efficacies by eradicating resistant, reduce the dosage of the drug and minimize toxicities on the normal cells. Gemcitabine (GEM), a nucleoside analogue, and atorvastatin (ATV), a cholesterol lowering agent, have shown anticancer effect with some limitations. The objective of this in vitro study was to evaluate the antitumor activity of the combination therapy of GEM and ATVencapsulated in a microemulsion (ME) formulation in the HCT116 colon cancer cells. The cytotoxicity and efficacy of the formulation were assessed by the 3- (4,5dimethylthiazole-2-yl)-2,5-diphyneltetrazolium bromide (MTT) assay. The mechanism of cell death was examined by observing the morphological changes of treated cells under light microscope, identifying apoptosis by using the ApopNexin apoptosis detection kit, and viewing the morphological changes in the chromatin structure stained with 4′,6-diamidino-2-phenylindole (DAPI) under the inverted fluorescence microscope. It has been found that reducing the concentration of GEM loaded on ME (GEM-ME) from 5μM to 1.67μM by combining it with 3.33μM of ATV in a ME formulation (GEM/2ATV-ME) has preserved the strong cytotoxicity of GEM-ME against HCT116 cells. The current study proved that formulating GEM with ATV in ME has improved the therapeutic potential of GEM and ATV as anticancer drugs.


BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Ahmed M. Senan ◽  
Binru Yin ◽  
Yaoyao Zhang ◽  
Mustapha M. Nasiru ◽  
Yong‐Mei Lyu ◽  
...  

AbstractWith the increasing demand for antimicrobial agents and the spread of antibiotic resistance in pathogens, the exploitation of plant oils to partly replace antibiotic emerges as an important source of fine chemicals, functional food utility and pharmaceutical industries. This work introduces a novel catalytic method of plant oils hydroxylation by Fe(III) citrate monohydrate (Fe3+-cit.)/Na2S2O8 catalyst. Methyl (9Z,12Z)-octadecadienoate (ML) was selected as an example of vegetable oils hydroxylation to its hydroxy-conjugated derivatives (CHML) in the presence of a new complex of Fe(II)-species. Methyl 9,12-di-hydroxyoctadecanoate 1, methyl-9-hydroxyoctadecanoate 2 and methyl (10E,12E)-octadecanoate 3 mixtures is produced under optimized condition with oxygen balloon. The specific hydroxylation activity was lower in the case of using Na2S2O8 alone as a catalyst. A chemical reaction has shown the main process converted of plantoils hydroxylation and (+ 16 Da) of OH- attached at the methyl linoleate (ML-OH). HPLC and MALDI-ToF-mass spectrometry were employed for determining the obtained products. It was found that adding oxidizing agents (Na2S2O8) to Fe3+ in the MeCN mixture with H2O would generate the new complex of Fe(II)-species, which improves the C-H activation. Hence, the present study demonstrated a new functional method for better usage of vegetable oils.Producing conjugated hydroxy-fatty acids/esters with better antipathogenic properties. CHML used in food industry, It has a potential pathway to food safety and packaging process with good advantages, fundamental to microbial resistance. Lastly, our findings showed that biological monitoring of CHML-minimum inhibitory concentration (MIC) inhibited growth of various gram-positive and gram-negative bacteria in vitro study. The produced CHML profiles were comparable to the corresponding to previousstudies and showed improved the inhibition efficiency over the respective kanamycin derivatives.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2223
Author(s):  
Moises Bustamante-Torres ◽  
Victor H. Pino-Ramos ◽  
David Romero-Fierro ◽  
Sandra P. Hidalgo-Bonilla ◽  
Héctor Magaña ◽  
...  

The design of new polymeric systems for antimicrobial drug release focused on medical/surgical procedures is of great interest in the biomedical area due to the high prevalence of bacterial infections in patients with wounds or burns. For this reason, in this work, we present a new design of pH-sensitive hydrogels copolymerized by a graft polymerization method (gamma rays), intended for localized prophylactic release of ciprofloxacin and silver nanoparticles (AgNPs) for potential topical bacterial infections. The synthesized hydrogels were copolymerized from acrylic acid (AAc) and agar. Cross-linked hydrogel film formation depended on monomer concentrations and the degree of radiation used (Cobalt-60). The obtained hydrogel films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical testing. The swelling of the hydrogels was evidenced by the influence of their pH-sensitiveness. The hydrogel was loaded with antimicrobial agents (AgNPs or ciprofloxacin), and their related activity was evaluated. Finally, the antimicrobial activity of biocidal-loaded hydrogel was tested against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) on in vitro conditions.


2021 ◽  
Author(s):  
Luca Mazzei ◽  
Lara Massai ◽  
Michele Cianci ◽  
Luigi Messori ◽  
Stefano Ciurli

A few gold compounds were recently found to show antimicrobial properties in vitro, holding great promise for the discovery of new drugs to overcome antibiotic resistance.


Author(s):  
Hetal Ashvin Kumar Mavani ◽  
In Meei Tew ◽  
Lishen Wong ◽  
Hsu Zenn Yew ◽  
Alida Mahyuddin ◽  
...  

Sodium hypochlorite (NaOCl), an effective endodontic irrigant against Enterococcus faecalis (EF), is harmful to periapical tissues. Natural pineapple-orange eco-enzymes (M-EE) and papaya eco-enzyme (P-EE) could be potential alternatives. This study aimed to assess the antimicrobial efficacy of M-EE and P-EE at different concentrations and fermentation periods against EF, compared to 2.5% NaOCl. Fermented M-EE and P-EE (3 and 6 months) at various concentrations were mixed with EF in a 96-well plate incubated for 24 h anaerobically. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of M-EE and P-EE were determined via EF growth observation. EF inhibition was quantitatively measured and compared between different irrigants using the one-way analysis of variance (ANOVA), and different fermentation periods using the independent-samples T-test. M-EE and P-EE showed MIC at 50% and MBC at 100% concentrations. There was no significant difference in antimicrobial effect when comparing M-EE and P-EE at 50% and 100% to 2.5% NaOCl. P-EE at 6 months fermentation exhibited higher EF inhibition compared to 3 months at concentrations of 25% (p = 0.017) and 0.78% (p = 0.009). The antimicrobial properties of M-EE and P-EE, at both 100% and 50% concentrations, are comparable to 2.5% NaOCl. They could therefore be potential alternative endodontic irrigants, but further studies are required.


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