scholarly journals Advantages and limitations of microtiter biofilm assays in the model of antibiofilm activity of Klebsiella phage KP34 and its depolymerase

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Agnieszka Latka ◽  
Zuzanna Drulis-Kawa

AbstractOne of the potential antibiofilm strategies is to use lytic phages and phage-derived polysaccharide depolymerases. The idea is to uncover bacteria embedded in the biofilm matrix making them accessible and vulnerable to antibacterials and the immune system. Here we present the antibiofilm efficiency of lytic phage KP34 equipped with virion-associated capsule degrading enzyme (depolymerase) and its recombinant depolymerase KP34p57, depolymerase-non-bearing phage KP15, and ciprofloxacin, separately and in combination, using a multidrug-resistant K. pneumoniae biofilm model. The most effective antibiofilm agents were (1) phage KP34 alone or in combination with ciprofloxacin/phage KP15, and (2) depolymerase KP34p57 with phage KP15 and ciprofloxacin. Secondly, applying the commonly used biofilm microtiter assays: (1) colony count, (2) LIVE/DEAD BacLight Bacterial Viability Kit, and (3) crystal violet (CV) biofilm staining, we unravelled the main advantages and limitations of the above methods in antibiofilm testing. The diverse mode of action of selected antimicrobials strongly influenced obtained results, including a false positive enlargement of biofilm mass (CV staining) while applying polysaccharide degrading agents. We suggest that to get a proper picture of antimicrobials’ effectiveness, multiple examination methods should be used and the results must be read considering the principle of each technique and the antibacterial mechanism.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Bing (Catherine) Wu ◽  
Evan F. Haney ◽  
Noushin Akhoundsadegh ◽  
Daniel Pletzer ◽  
Michael J. Trimble ◽  
...  

AbstractBacterial biofilms cause 65% of all human infections and are highly resistant to antibiotic therapy but lack specific treatments. To provide a human organoid model for studying host-microbe interplay and enabling screening for novel antibiofilm agents, a human epidermis organoid model with robust methicillin-resistant Staphylococcus aureus (MRSA) USA300 and Pseudomonas aeruginosa PAO1 biofilm was developed. Treatment of 1-day and 3-day MRSA and PAO1 biofilms with antibiofilm peptide DJK-5 significantly and substantially reduced the bacterial burden. This model enabled the screening of synthetic host defense peptides, revealing their superior antibiofilm activity against MRSA compared to the antibiotic mupirocin. The model was extended to evaluate thermally wounded skin infected with MRSA biofilms resulting in increased bacterial load, cytotoxicity, and pro-inflammatory cytokine levels that were all reduced upon treatment with DJK-5. Combination treatment of DJK-5 with an anti-inflammatory peptide, 1002, further reduced cytotoxicity and skin inflammation.


Author(s):  
Megha Periyappilly Radhakrishnan ◽  
Karthika Suryaletha ◽  
Aparna Shankar ◽  
Akhila Velappan Savithri ◽  
Sanil George ◽  
...  

: Chronic wound biofilm infections are a threat to the population with respect to morbidity and mortality. Presence of multidrug resistant bacterial pathogens in chronic wound renders the action of antibiotics and antibiofilm agents difficult. Therefore an alternative therapy is essential for reducing bacterial biofilm burden. In this scenario, the peptide based antibiofilm therapy for chronic wound biofilm management seeks more attention. Synthetic peptide with a broad range of antibiofilm activity against preformed and established biofilms, ability to kill multispecies bacteria within biofilms and combinatorial activity with other antimicrobial agents give significant insights. In this review we portray the possibilities and difficulties of peptide mediated treatment in chronic wounds biofilm management and how it can be clinically translated into a product.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 761
Author(s):  
Mona M. Okba ◽  
Riham A. El-Shiekh ◽  
Mohammed Abu-Elghait ◽  
Mansour Sobeh ◽  
Rehab M. S. Ashour

The development of multidrug-resistant bacterial strains is a worldwide emerging problem that needs a global solution. Exploring new natural antibiofilm agents is one of the most important alternative therapies in combating bacterial infections. This study aimed at testing the antimicrobial potential of Eucalyptus sideroxylon flowers extract (ESFE) against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans prior to testing the antibiofilm activity against S. aureus, P. aeruginosa and C. albicans. ESFE demonstrated antimicrobial activity and promising inhibition activity against methicillin-resistant S. aureus (MRSA) biofilm formation up to 95.9% (p < 0.05) at a concentration of 0.05 mg/mL and eradicated C. albicans biofilm formation up to 71.2% (p < 0.05) at a concentration of 0.7 mg/mL. LC-MS analysis allowed the tentative identification of eighty-three secondary metabolites: 21 phloroglucinol, 18 terpenes, 16 flavonoids, 7 oleuropeic acid derivatives, 7 ellagic acid derivatives, 6 gallic acid derivatives, 3 phenolic acids, 3 fatty acids and 2 miscellaneous. In conclusion, E. sideroxylon is a rich source of effective constituents that promote its valorization as a promising candidate in the management of multidrug-resistant bacterial infections.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1182
Author(s):  
Claudia Ramirez-Sanchez ◽  
Francis Gonzales ◽  
Maureen Buckley ◽  
Biswajit Biswas ◽  
Matthew Henry ◽  
...  

Successful joint replacement is a life-enhancing procedure with significant growth in the past decade. Prosthetic joint infection occurs rarely; it is a biofilm-based infection that is poorly responsive to antibiotic alone. Recent interest in bacteriophage therapy has made it possible to treat some biofilm-based infections, as well as those caused by multidrug-resistant pathogens, successfully when conventional antibiotic therapy has failed. Here, we describe the case of a 61-year-old woman who was successfully treated after a second cycle of bacteriophage therapy administered at the time of a two-stage exchange procedure for a persistent methicillin-sensitive Staphylococcus aureus (MSSA) prosthetic knee-joint infection. We highlight the safety and efficacy of both intravenous and intra-articular infusions of bacteriophage therapy, a successful outcome with a single lytic phage, and the development of serum neutralization with prolonged treatment.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4654
Author(s):  
Suthee Mangmee ◽  
Onrapak Reamtong ◽  
Thareerat Kalambaheti ◽  
Sittiruk Roytrakul ◽  
Piengchan Sonthayanon

Antimicrobial peptides are promising molecules to address the global antibiotic resistance problem, however, optimization to achieve favorable potency and safety is required. Here, a peptide-template modification approach was employed to design physicochemical variants based on net charge, hydrophobicity, enantiomer, and terminal group. All variants of the scorpion venom peptide BmKn-2 with amphipathic α-helical cationic structure exhibited an increased antibacterial potency when evaluated against multidrug-resistant Salmonella isolates at a MIC range of 4–8 µM. They revealed antibiofilm activity in a dose-dependent manner. Sheep red blood cells were used to evaluate hemolytic and cell selectivity properties. Peptide Kn2-5R-NH2, dKn2-5R-NH2, and 2F-Kn2-5R-NH2 (variants with +6 charges carrying amidated C-terminus) showed stronger antibacterial activity than Kn2-5R (a variant with +5 charges bearing free-carboxyl group at C-terminus). Peptide dKn2-5R-NH2 (d-enantiomer) exhibited slightly weaker antibacterial activity with much less hemolytic activity (higher hemolytic concentration 50) than Kn2-5R-NH2 (l-enantiomer). Furthermore, peptide Kn2-5R with the least hydrophobicity had the lowest hemolytic activity and showed the highest specificity to Salmonella (the highest selectivity index). This study also explained the relationship of peptide physicochemical properties and bioactivities that would fulfill and accelerate progress in peptide antibiotic research and development.


2021 ◽  
Author(s):  
Giuseppe Ancona ◽  
Laura Alagna ◽  
Andrea Lombardi ◽  
Emanuele Palomba ◽  
Valeria Castelli ◽  
...  

Liver transplantation (LT) is a life-saving strategy for patients with end-stage liver disease, hepatocellular carcinoma and acute liver failure. LT success can be hampered by several short-term and long-term complications. Among them, bacterial infections, especially due to multidrug-resistant germs, are particularly frequent with a prevalence between 19 and 33% in the first 100 days after transplantation. In the last decades, a number of studies have highlighted how gut microbiota (GM) is involved in several essential functions to ensure the intestinal homeostasis, becoming one of the most important virtual metabolic organs. GM works through different axes with other organs, and the gut-liver axis is among the most relevant and investigated ones. Any alteration or disruption of GM is defined as dysbiosis. Peculiar phenotypes of GM dysbiosis have been associated to several liver conditions and complications, such as chronic hepatitis, fatty liver disease, cirrhosis and hepatocellular carcinoma. Moreover, there is growing evidence of the crucial role of GM in shaping the immune response, both locally and systemically, against pathogens. This paves the way to the manipulation of GM as a therapeutic instrument to modulate the infectious risk and outcome. In this minireview we provide an overview of the current understanding on the interplay between gut microbiota and the immune system in liver transplant recipients and the role of the former in infections.


2021 ◽  
Author(s):  
Rodrigo L Fabri ◽  
Jhamine C O Freitas ◽  
Ari S O Lemos ◽  
Lara M Campos ◽  
Irley O M Diniz ◽  
...  

Abstract Spilanthol is a bioactive alkylamide from the native Amazon plant species, Acmella oleracea. However, antifungal activities of spilanthol and its application to the therapeutic treatment of candidiasis remains to be explored. This study sought to evaluate the in vitro and in vivo antifungal activity of spilanthol previously isolated from A. oleracea (spilanthol(AcO)) against Candida albicans ATCC® 10231™, a multidrug-resistant fungal strain. Microdilution methods were used to determine inhibitory and fungicidal concentrations of spilanthol(AcO). In planktonic cultures, the fungal growth kinetics, yeast cell metabolic activity, cell membrane permeability and cell wall integrity were investigated. The effect of spilanthol(AcO) on the proliferation and adhesion of fungal biofilms was evaluated by whole slide imaging and scanning electron microscopy. The biochemical composition of the biofilm matrix was also analyzed. In parallel, spilanthol(AcO) was tested in vivo in an experimental vulvovaginal candidiasis model. Our in vitro analyses in C. albicans planktonic cultures detected a significant inhibitory effect of spilanthol(AcO), which affects both yeast cell membrane and cell wall integrity, interfering with the fungus growth. C. albicans biofilm proliferation and adhesion, as well as, carbohydrates and DNA in biofilm matrix were reduced after spilanthol(AcO) treatment. Moreover, infected rats treated with spilanthol(AcO) showed consistent reduction of both fungal burden and inflammatory processes compared to the untreated animals. Altogether, our findings demonstrated that spilanthol(AcO) is an bioactive compound against planktonic and biofilm forms of a multidrug resistant C. albicans strain. Furthermore, spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans. Lay Abstract This study sought to evaluate the antifungal activity of spilanthol against Candida albicans ATCC® 10 231™, a multidrug-resistant fungal strain. Our findings demonstrated that spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans.


2020 ◽  
Author(s):  
Himanshi Singh ◽  
Avinash Y. Gahane ◽  
Virender Singh ◽  
Shreya Ghosh ◽  
Ashwani Kumar Thakur

AbstractBackgroundBiofilm associated infections are the major contributor of mortality, morbidity and financial burden in patients with bacterial infection. Molecules with surfactant behaviour are known to show significant antibiofilm effect against these infections. Thus, newly discovered antibacterial Fmoc-phenylalanine (Fmoc-F) and other Fmoc-amino acids (Fmoc-AA) with surfactant properties, could have potential antibiofilm properties.ObjectivesTo evaluate and characterise the antibiofilm activity of Fmoc-F and some Fmoc-AA against various clinically relevant bacteria.MethodsBiofilm inhibition and eradication was evaluated by crystal violet staining procedure along with scanning electron microscopy (SEM). Attenuated Total Reflection - Fourier Transform Infrared Spectroscopy (ATR-FTIR), Biochemical assays and Congo red staining were employed to investigate mechanism of antibiofilm action.ResultsWe showed that Fmoc-F not only inhibits the biofilm formation in S. aureus and P. aeruginosa, but also eradicates the already formed biofilms over the surface. Further, Fmoc-F coated glass surface resists S. aureus and P. aeruginosa biofilm formation and attachment, when biofilm is grown over the surface. The mechanistic investigation suggests that Fmoc-F reduces the ECM components such as proteins carbohydrates and eDNA in the biofilm and affect its stability via direct interactions with ECM components and/ or indirectly through reducing bacterial cell population. Finally, we showed that Fmoc-F treatment in combination with other antibiotics such as vancomycin and ampicillin synergistically inhibit biofilm formation.ConclusionsOverall, the study demonstrates the potential application of Fmoc-F and other Fmoc-AA molecules individually as well as in combination as antibiofilm agents and antibiofilm coating material for treating biofilm associated infections.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shaoe Zhang ◽  
Xiao Wang ◽  
Xiaotao Shi ◽  
Honglue Tan ◽  
Himanshu Garg

Background. External socking and washing with the Chinese herbal Sanhuang Jiedu decoction (SHJD) can effectively control local limb infections with bone and implant exposure. However, the antibiofilm activities of this decoction in vitro have not yet been investigated. Therefore, the aim of this study was to examine the effects and characteristics of SHJD on the mature biofilms of multidrug-resistant staphylococci on a titanium surface. Methods. Biofilm-forming methicillin-resistant Staphylococcus epidermidis ATCC 35984 and S. aureus ATCC 43330, and non-biofilm-forming S. epidermidis ATCC 12228 were selected as the experimental strains. The mature biofilms were prepared on titanium surfaces. The five experimental groups were based on dilution concentrations (DC) of SHJD: the control group (biofilm incubated with 0.85% NaCl solution), the SHJD (DC:1/8) group (initial SHJD solution was diluted 1/8), the SHJD (DC:1/4) group, the SHJD (DC:1/2) group, and the SHJD (DC:1/1) group (initial SHJD solution). The effects of SHJD on the mature biofilms were observed with the bacterial spread plate method, crystal violet (CV) staining, scanning electron microscopy, and confocal laser scanning microscopy. Results. After culture in tryptic soy broth for 72 h, ATCC 43300 and ATCC 35984 produced mature biofilms and ATCC 12228 did not. The optical density value of ATCC 12228 was 0.11 ± 0.02 , significantly lower than that of ATCC 35984 ( 0.42 ± 0.05 ) or ATCC 43300 ( 0.41 ± 0.03 ) ( P < 0.05 ). The mature biofilms of ATCC 43300 and ATCC 35984 clearly disintegrated when incubated for 12–24 h with SHJD (DC:1/1) or SHJD (DC:1/2), showing only scattered bacterial adhesion. In the SHJD (DC:1/4) group, although many residual bacterial colonies still clustered together, presenting a biofilm structure, it was very looser than that in the SHJD (DC:1/8) group in which the biofilm was similar to that in the control group. For ATCC 12228, only colony adhesion was observed, and the number of colonies decreased as the concentration of SHJD or the culture period increased. The quantitative results for the bacterial spread plate and CV staining showed significant differences between the SHJD groups ( P < 0.05 ). Conclusion. SHJD has antibiofilm activity against multidrug-resistant Staphylococcus strains. It weakens or disrupts already-formed mature biofilms on titanium surfaces in a concentration- and incubation time-dependent manner.


Sign in / Sign up

Export Citation Format

Share Document