scholarly journals Isolation, Characterization, and Comparison of Efficiencies of Bacteriophages to Reduce Planktonic and Biofilm-Associated Staphylococcus aureus

2020 ◽  
Vol 10 (03) ◽  
pp. 102-108
Author(s):  
Anoopkrishna Rai ◽  
Rajeshwari V. Vittal ◽  
Juliet R. Mohan Raj
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Viable Cell ◽  
Viable Count ◽  
Dna Fingerprint ◽  
Planktonic Cells ◽  
Microtiter Plates ◽  
Reduction Assay ◽  
Need To Evaluate

Abstract Introduction In the present era, wherein occurrence of antimicrobial resistance compounded with biofilms in disease conditions has rendered present antibiotic therapy ineffective, the need for alternative strategies to treat bacterial infections has brought bacteriophages to the forefront. The antimicrobial activity of phages is often determined by a viable cell reduction assay which focuses only on planktonic forms. The physiology of an organism in biofilm differs from those that are planktonic; hence, there is a need to evaluate the activity of phages both on planktonic forms, as well as on biofilms, to select candidate therapeutic phages. Materials and Methods Bacteriophages for Staphylococcus aureus were isolated from environmental samples and characterized based on growth kinetics and DNA fingerprint patterns. Activity of isolated phages on planktonic forms was determined by viable count reduction assay. Phage ability to prevent biofilm formation and ability to disperse formed biofilms were performed in 96-well microtiter plates and biofilm estimated by crystal violet assay. Results Four bacteriophages designated, that is, P3, PD1, PE1, and PE2, were isolated and characterized. Planktonic cells of S. aureus were found to be sensitive to phages PD1, PE1, and PE2. Phages PD1 and PE2 were efficient in preventing biofilm formation and phages PD1, PE1, and P3 were efficient in dispersing formed biofilms. Conclusion The ability of some phages to disperse biofilms effectively, while unable to show the same efficiency on planktonic cells, indicates that viable count reduction assay alone may not be a sufficient tool to imply bactericidal activity of bacteriophages, especially while trying to eradicate biofilms.

scholarly journals RNA III Inhibiting Peptide Inhibits In Vivo Biofilm Formation by Drug-Resistant Staphylococcus aureus

2003 ◽  
Vol 47 (6) ◽  
pp. 1979-1983 ◽  
Author(s):  
Andrea Giacometti ◽  
Oscar Cirioni ◽  
Yael Gov ◽  
Roberto Ghiselli ◽  
Maria Simona Del Prete ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Quorum Sensing ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Drug Resistant ◽  
Dacron Graft

ABSTRACT Staphylococcus aureus is a prevalent cause of bacterial infections associated with indwelling medical devices. RNA III inhibiting peptide (RIP) is known to inhibit S. aureus pathogenesis by disrupting quorum-sensing mechanisms. RIP was tested in the present study for its ability to inhibit S. aureus biofilm formation in a rat Dacron graft model. The activity of RIP was synergistic with those of antibiotics for the complete prevention of drug-resistant S. aureus infections.

scholarly journals Antibacterial and Antibiofilm Potential of Sea Anemone (Stichodactyla haddoni)-Isolated Vibrio (V. parahaemolyticus and V. alginolyticus), and Pseudoalteromonas (P. gelatinilytica and P. piscicida) Against Staphylococcus aureus and Pseudomonas aeruginosa

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Neda Fazeli ◽  
Akram Sadat Naeemi ◽  
Seyed Amir Hossein Jalali ◽  
Hojjatollah Zamani
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Sea Anemone ◽  
Broth Culture ◽  
Antibiofilm Activity ◽  
Microtiter Plates ◽  
Protease Enzyme ◽  
Molecular Identification Methods ◽  
Stichodactyla Haddoni

Background: Staphylococcus aureus and Pseudomonas aeruginosa are important human bacterial pathogens, which are resistant to several antibiotics. One of the main causes of their resistance is the ability of biofilm formation. Objectives: The present study aimed to evaluate the antibacterial and antibiofilm activity of the extracts of Vibrio parahaemolyticus, V. alginolyticus, Pseudoalteromonas gelatinilytica, and Pseudoalteromonas piscicida isolated from sea anemone (Stichodactyla haddoni) against S. aureus and P. aeruginosa. Methods: Four isolated bacteria were identified using biochemical and molecular identification methods, and their extracts were obtained by mixing the cell-free supernatants from their old broth culture using ethyl acetate and methanol as the solvents. The agar well-diffusion and micro-dilution methods were also applied to determine the antibacterial activity, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC) of the extracts. The ability of the extracts to inhibit biofilm formation and disrupt the preformed biofilm of the pathogens was attained through crystal violet staining in 96-well microtiter plates. To determine the nature of the extracts, they were exposed to protease enzyme, and the antibiofilm activity was compared with the untreated extracts. Results: The extracts of the four isolated bacteria inhibited bacterial growth and biofilm formation and disrupted the preformed biofilm of S. aureus (MIC = BIC = 600 µg/mL) and P. aeruginosa (MIC = BIC = 300 µg/mL). In addition, the active compounds of the extracts with antibiofilm activities were mainly proteases. Conclusions: According to the results, V. parahaemolyticus, V. alginolyticus, P. gelatinilytica, and P. piscicida had antibacterial and antibiofilm potential against S. aureus and P. aeruginosa, and their extract could also be further analyzed as an alternative to antibiotics.

scholarly journals Organoselenium Coating on Cellulose Inhibits the Formation of Biofilms by Pseudomonas aeruginosa and Staphylococcus aureus

2009 ◽  
Vol 75 (11) ◽  
pp. 3586-3592 ◽  
Author(s):  
Phat L. Tran ◽  
Adrienne A. Hammond ◽  
Thomas Mosley ◽  
Janette Cortez ◽  
Tracy Gray ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Bacterial Attachment ◽  
Wound Dressings ◽  
Aqueous Environment ◽  
Burn Victims ◽  
Surgical Wounds

ABSTRACT Among the most difficult bacterial infections encountered in treating patients are wound infections, which may occur in burn victims, patients with traumatic wounds, necrotic lesions in people with diabetes, and patients with surgical wounds. Within a wound, infecting bacteria frequently develop biofilms. Many current wound dressings are impregnated with antimicrobial agents, such as silver or antibiotics. Diffusion of the agent(s) from the dressing may damage or destroy nearby healthy tissue as well as compromise the effectiveness of the dressing. In contrast, the antimicrobial agent selenium can be covalently attached to the surfaces of a dressing, prolonging its effectiveness. We examined the effectiveness of an organoselenium coating on cellulose discs in inhibiting Pseudomonas aeruginosa and Staphylococcus aureus biofilm formation. Colony biofilm assays revealed that cellulose discs coated with organoselenium completely inhibited P. aeruginosa and S. aureus biofilm formation. Scanning electron microscopy of the cellulose discs confirmed these results. Additionally, the coating on the cellulose discs was stable and effective after a week of incubation in phosphate-buffered saline. These results demonstrate that 0.2% selenium in a coating on cellulose discs effectively inhibits bacterial attachment and biofilm formation and that, unlike other antimicrobial agents, longer periods of exposure to an aqueous environment do not compromise the effectiveness of the coating.

scholarly journals Antibacterial Effects of Phage Lysin LysGH15 on Planktonic Cells and Biofilms of Diverse Staphylococci

2018 ◽  
Vol 84 (15) ◽  
Author(s):  
Yufeng Zhang ◽  
Mengjun Cheng ◽  
Hao Zhang ◽  
Jiaxin Dai ◽  
Zhimin Guo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Planktonic Cells ◽  
Content Type ◽  
Resistant Strains ◽  
Staphylococcus Hominis ◽  
Phage Lysin

ABSTRACT Treatment of infections caused by staphylococci has become more difficult because of the emergence of multidrug-resistant strains as well as biofilm formation. In this study, we observed the ability of the phage lysin LysGH15 to eliminate staphylococcal planktonic cells and biofilms formed by Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus hominis. All these strains were sensitive to LysGH15, showing reductions in bacterial counts of approximately 4 log units within 30 min after treatment with 20 μg/ml of LysGH15, and the MICs ranged from 8 μg/ml to 32 μg/ml. LysGH15 efficiently prevented biofilm formation by the four staphylococcal species at a dose of 50 μg/ml. At a higher dose (100 μg/ml), LysGH15 also showed notable disrupting activity against 24-h and 72-h biofilms formed by S. aureus and coagulase-negative species. In the in vivo experiments, a single intraperitoneal injection of LysGH15 (20 μg/mouse) administered 1 h after the injection of S. epidermidis at double the minimum lethal dose was sufficient to protect the mice. The S. epidermidis cell counts were 4 log units lower in the blood and 3 log units lower in the organs of mice 24 h after treatment with LysGH15 than in the untreated control mice. LysGH15 reduced cytokine levels in the blood and improved pathological changes in the organs. The broad antistaphylococcal activity exerted by LysGH15 on planktonic cells and biofilms makes LysGH15 a valuable treatment option for biofilm-related or non-biofilm-related staphylococcal infections. IMPORTANCE Most staphylococcal species are major causes of health care- and community-associated infections. In particular, Staphylococcus aureus is a common and dangerous pathogen, and Staphylococcus epidermidis is a ubiquitous skin commensal and opportunistic pathogen. Treatment of infections caused by staphylococci has become more difficult because of the emergence of multidrug-resistant strains as well as biofilm formation. In this study, we found that all tested S. aureus, S. epidermidis, Staphylococcus haemolyticus, and Staphylococcus hominis strains were sensitive to the phage lysin LysGH15 (MICs ranging from 8 to 32 μg/ml). More importantly, LysGH15 not only prevented biofilm formation by these staphylococci but also disrupted 24-h and 72-h biofilms. Furthermore, the in vivo efficacy of LysGH15 was demonstrated in a mouse model of S. epidermidis bacteremia. Thus, LysGH15 exhibits therapeutic potential for treating biofilm-related or non-biofilm-related infections caused by diverse staphylococci.

scholarly journals Unpredictable Effects of Rifampin as an Adjunctive Agent in Elimination of Rifampin-Susceptible and -Resistant Staphylococcus aureus Strains Grown in Biofilms

2010 ◽  
Vol 54 (9) ◽  
pp. 3907-3912 ◽  
Author(s):  
Sander Croes ◽  
Patrick S. Beisser ◽  
Cees Neef ◽  
Cathrien A. Bruggeman ◽  
Ellen E. Stobberingh
Keyword(s):  
Staphylococcus Aureus ◽  
Genetic Background ◽  
Viable Cell ◽  
Viable Count ◽  
Cell Counts ◽  
Resistant Strains ◽  
Resistant Mutants ◽  
Static Conditions ◽  
Additional Value ◽  
Count Change

ABSTRACT The use of rifampin as an adjunct in biofilm-associated infections is based on the ability to penetrate into biofilms and a presumed activity against dormant bacteria. Yet, its efficacy remains contradictory, and rifampin-resistant strains frequently emerge during therapy. Therefore, the efficacy against rifampin-susceptible and isogenic rifampin-resistant methicillin-susceptible Staphylococcus aureus (MSSA) strains was evaluated. Biofilms were generated under static conditions using MSSA with various genetic backgrounds. Oxacillin alone or with rifampin at various concentrations was subsequently added, and after 24 h biomass and viable cell counts were determined. Upon rifampin addition, interstrain variations in viable count change, ranging from a tendency toward antagonism to synergy, were observed among all strains tested, irrespective of the genetic background of the strain. Similar variations were observed in changes in biomass. The decrease in viable count upon rifampin addition was negatively correlated to formation of large amounts of biomass, since strains embedded by more biomass showed a diminished reduction in viable count. Rifampin (1 μg/ml) as adjunct to oxacillin achieved greater reductions in biomass produced by most rifampin-susceptible isolates, ranging from 17 to 54%, compared to 4% for oxacillin alone. In contrast, rifampin had no additional value in reduction of biomass of isogenic rifampin-resistant mutants. At subinhibitory concentrations of rifampin (0.008 μg/ml), none of the strains tested yielded an extra reduction in biomass that was ≥40%. In conclusion, the effects of rifampin as adjunct on biomass and viable count were unpredictable, and the use of rifampin against biofilm containing rifampin-resistant strains seems unwarranted.

scholarly journals Optimum cultural conditions to achieve the best biofilm formation and high level icaA transcription by Staphylococcus aureus

2021 ◽  
Author(s):  
Aram Sharifi ◽  
Abdolmajid Mohammadzadeh ◽  
Pezhman Mahmoodi ◽  
Taghi Zahraei Salehi
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Culture Media ◽  
Brain Heart Infusion ◽  
Microtiter Plate ◽  
Broth Culture ◽  
Microtiter Plates ◽  
Cultural Conditions ◽  
Slime Layer ◽  
High Level

Abstract Background The aim of this study was to investigate the influences of different broth culture media supplemented with glucose, on the biofilm formation and ica expression of Staphylococcus aureus. The phenotypic ability to adhere to a polystyrene surface and to produce slime layer were evaluated using microtiter plate test (MtP) and Congo red tube test, respectively. Using PCR, the presence of ica locus in S. aureus strains was confirmed and subsequently, quantitative real-time RT-PCR was performed to investigate transcription of icaA in various media including Tryptic soy broth (TSB), Brain-heart infusion broth (BHIB), (Nutrient broth) NB and (Muller-Hinton broth) MHB contained 0, 0.25, 0.5, 1 and 2% glucose. Results Our results showed that although all of the studied strains adhered to the wells of polystyrene microtiter plates, the optimum rate of biofilm formation was observed for TSB medium contained 1% glucose, but biofilm formation was not significantly different in NB, MHB and BHIB media. Supplementation of all media with 1% glucose led to the highest production of biofilm formation and in all of media transcription of icaA was increased with glucose addition to one present. Conclusions The results of the present study indicated that TSB medium supplemented with 1% glucose was the most appropriate medium for evaluation of biofilm formation by S. aureus isolates.

scholarly journals Resistance Profile From Staphylococcus Aureus And Pseudomonas Aeruginosa Obtained From Tracheostomized Children

2020 ◽  
Author(s):  
Juliana Afonso de Almeida ◽  
Caroline Espíndola de Barros ◽  
Gustavo Henrique da Silva Ayres ◽  
Mariana Helena e Silva ◽  
Andressa Santos Liberal ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Congo Red ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Molecular Profile ◽  
Resistance Profile ◽  
Phenotypic Tests ◽  
Tracheal Secretion

Abstract Background The tracheostomized patients exhibit high risks of bacterial infections, because the tracheal tube acts as a gateway to these microorganisms. The objective was to characterize microbiologically the tracheal secretion of tracheostomized children, to evaluate the biofilm formation, and to study the phenotypic and molecular profile of antimicrobial resistance of Staphylococcus aureus and Pseudomonas aeruginosa isolated. Methods The study collected 88 tracheal secretion samples. The material processed by phenotypic tests were performed for bacterial identification. For identification of the biofilm, the Congo red agar test and the plaque microtiter test were used, and the qPCR method was used to resistance verification. Results Were obtained 27 samples of S. aureus and 71 of P. aeruginosa . All S. aureus samples were positive for biofilm formation on Congo red agar test. In antibiogram test, S. aureus showed resistance to seven drugs. Regarding the identification of resistance genes, were amplificated bla Z in 42.8% from S. aureus and mec A in 28.6% of them. Pseudomonas aeruginosa presented resistance to eight drugs. The most frequent chromosomal genes were bla OXA with 66.7% and bla KPC with 58.3%. To plasmidial DNA, was highlighted bla NDM with 58.3% positive. Conclusion The S. aureus and P. aeruginosa characterization of colonization from lower respiratory tract associated with the use of the device in tracheotomy patients, and the physiology and antimicrobial resistance profile, will help health professionals to choose the most appropriate treatment to be administered in children with tracheotomy, increasing the chances of airway restoration and decannulation.

scholarly journals Synthesis and biological evaluation of new cephalosporin derivatives containing cyclic disulfide moieties

2021 ◽  
Author(s):  
Inga S. Shchelik ◽  
Karl Gademann
Keyword(s):  
Biofilm Formation ◽  
Bacterial Infections ◽  
Biological Evaluation ◽  
Steady Increase ◽  
Planktonic Cells ◽  
Gram Negative ◽  
Successful Group ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Synthesis And Biological Evaluation

Due to a steady increase of microbial resistance, there is a need to increase the effectiveness of antibiotic performance by involving additional mechanisms of their penetration or retention for their better action. Cephalosporins are a successful group of antibiotics to combat pathogenic microorganisms, including drug-resistant strains. In this study, we investigated the effect of newly synthesized cephalosporin derivatives with cyclic disulfide modifications against several Gram-positive and Gram-negative strains as well as against biofilm formation. The incorporation of asparagusic acid was found to be effective in improving the activity of the drug against Gram-negative strains. Furthermore, we could demonstrate the successful inhibition of biofilm formation for S. aureus and P. aeruginosa at similar concentrations as obtained against planktonic cells. We propose that the incorporation of cyclic disulfides is one additional strategy to improve antibiotic activity and to combat bacterial infections.

scholarly journals Synovial Fluid-Induced Aggregation Occurs across Staphylococcus aureus Clinical Isolates and is Mechanistically Independent of Attached Biofilm Formation

2021 ◽  
Author(s):  
Amelia Staats ◽  
Peter W. Burback ◽  
Mostafa Eltobgy ◽  
Dana M. Parker ◽  
Amal O. Amer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Synovial Fluid ◽  
Prosthetic Joint Infection ◽  
Orthopedic Surgery ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Joint Infection ◽  
Synovial Joint ◽  
Prosthetic Joint ◽  
Induced Aggregation

Bacterial infections of hip and knee implants are rare but devastating complications of orthopedic surgery. Despite a widespread appreciation of the considerable financial, physical, and emotional burden associated with the development of a prosthetic joint infection, the establishment of bacteria in the synovial joint remains poorly understood.

Analysis of the Bacterial Vesicles' Enhanced Toxicological Threat Via Electron Microscopy

2017 ◽  
pp. 19-43
Author(s):  
Roberta Curia ◽  
Marziale Milani ◽  
Lyubov V Didenko ◽  
George A Avtandilov ◽  
Natalia V Shevlyagina ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Plastic Material ◽  
Membrane Vesicles ◽  
Host Cells ◽  
Dental Prostheses ◽  
Bacterial Secretion

This study shows the importance of electron microscopy in the analysis of the interaction of microorganisms (Staphylococcus aureus) with polymeric (polyurethane) dental prostheses. Starting from the biofilm formation and the biodestruction of the plastic material resulting in the production of polyurethane nanoparticles, the focus is on the bacterial secretion of membrane vesicles (in the range of 20-50 nm) loaded with plastic nanoparticles (from 2-3 to 10 nm) and on the toxicological threat that these delivery devices represent when interacting with host cells. The nanoparticles deliverance led by the bacterial infections dynamics opens new ways to the possibility of delivering drugs to selected cells.

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