scholarly journals Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics

2021 ◽  
Vol 12 ◽  
Author(s):  
Agathe Boudet ◽  
Pauline Sorlin ◽  
Cassandra Pouget ◽  
Raphaël Chiron ◽  
Jean-Philippe Lavigne ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Ring Test ◽  
Methicillin Resistant ◽  
Lung Dysfunction ◽  
Chronic Colonization ◽  
Strain Dependent

Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.

scholarly journals Fungal Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 Inhibits the Growth of Skin Pathogenic Bacterium and Attenuates Biofilms of Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 28 (4) ◽  
pp. 24-36
Author(s):  
Mohd Taufiq Mat Jalil ◽  
Darah Ibrahim
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cell Damage ◽  
Multidrug Resistant ◽  
Industrial Biotechnology ◽  
Bacterial Cells ◽  
Methicillin Resistant ◽  
Fungal Extract

Background: The emergence of multidrug-resistant pathogens associated with biofilm formation can cause life-threatening infections to humans. Therefore, the present study aims to evaluate the effects of the fungal extract of Lasiodiplodia pseudotheobromae (L. pseudotheobromae) Industrial Biotechnology Research Laboratory (IBRL) OS-64 on bacterial cells and the biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA). Methods: Broth microdilution and semi-quantitative adherence assays were conducted to determine the anti-biofilm activity of the fungal extract. Light and scanning electron microscopy (SEM) analyses were performed to observe the effect of the fungal extract on biofilm formation by MRSA. Results: The transmission electron microscopy (TEM) microphotographs showed that the bacterial cells were severely damaged upon 24 h exposure to the extract and displayed several symptoms such as cell shrinkage and breakage. Meanwhile, results from the antibiofilm study indicated the extract attenuated the initial and preformed biofilms of MRSA by 80.82% and 61.39%, respectively. The initial biofilm was more sensitive to the extract compared to the pre-formed biofilm, as evidenced by the light microscopy and SEM observations that demonstrated more severe bacterial cell damage on the initial biofilms compared to pre-formed biofilms. Conclusion: The ethyl acetate extract of L. pseudotheobromae IBRL OS-64 significantly inhibited bacterial cells growth and eliminated biofilm formation by MRSA.

The effects of NX-AS-401 on methicillin resistant Staphylococcus aureus

2021 ◽  
Author(s):  
◽  
Phillip Butterick
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Galleria Mellonella ◽  
Standard Of Care ◽  
Health Concern ◽  
Current Standard ◽  
Methicillin Resistant ◽  
Biofilm Development ◽  
Strain Dependent

Antimicrobial resistance is a global health concern, with once treatable infections becoming resistant to current standard of care antimicrobials. The search for new antimicrobials has led Neem Biotech Ltd. to manufacture NX-AS-401 an ajoene containing compound derived from Allium sativuum, commonly known as garlic. The research contained within this thesis aimed to identify the effects of NX-AS-401 on Methicillin Resistant Staphylococcus aureus (MRSA), one of the most well documented and commonly isolated antimicrobial resistant bacterial pathogens. A multi-stage approach was utilised, identifying how NX-AS-401 affects planktonic growth, biofilm development and virulence factor production. In Chapters 3 and 4 initial comparison between different NX-AS-401 formulations was performed in determined that ajoene content did not alter the antimicrobial effect of NX-AS-401. EUCAST broth microdilution compared NX-AS-401 to current standard of care antibiotic and determined effective inhibitory and bactericidal concentrations as 128 µg/ml and 2048 µg/ml respectively. When NX-AS-401 was used in combination with various antibiotic classes a synergistic effect was identified and the inhibitory concentrations of both agents were reduced. The primary focus on Chapter 5 was how NX-AS-401 affected S. aureus biofilm formation. NX-AS-401 concentrations of 32 µg/ml inhibited biofilm formation and a concentration of 512 µg/ml caused disruption of pre-established biofilms. These effects were confirmed using scanning electron microscopy and confocal microscopy with live/dead staining. In gene expression studies it was determined that the effects of NX-AS-401 on S. aureus biofilms were strain dependent and a target gene was not identified. Chapter 6 demonstrated that NX-AS-401 did not alter the production of Staphylococcus aureus exo-enzyme production in vitro during phenotypic studies. In Galleria mellonella low NX-AS-401 concentrations assisted in the recovery from S. aureus in a strain dependent manner, however, high concentrations caused increased Galleria mellonella fatality. NX-AS-401 altered the ability of S. aureus cells to invade human epithelial cells but did not prevent adhesion of S. aureus to the cells. NX-AS-401 has multiple effects on S. aureus with the ability to affect both planktonic cells and biofilm structure showing promise as an antimicrobial. Its main effects are growth inhibition and biofilm disruption rather than causing bacterial cell death. These attributes and the synergistic effects between NX-AS-401 and multiple antibiotic classes, indicate NX-AS-401 has potential as a strong antimicrobial adjuvant.

scholarly journals Hesperidin inhibits biofilm formation, virulence and staphyloxanthin synthesis in methicillin resistant Staphylococcus aureus by targeting SarA and CrtM: An in vitro and in silico approach

2021 ◽  
Author(s):  
Vijayakumar Karuppiah ◽  
Muhilvannan Seralathan ◽  
Arunvignesh Mani
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Methicillin Resistant ◽  
Atcc Strain ◽  
Multidrug Resistant Bacterium ◽  
Fibronectin Binding Protein ◽  
Inhibitory Potential

Abstract Methicillin resistant Staphylococcus aureus is considered the multidrug resistant bacterium due to developing biofilm formation associated with antimicrobial resistance mechanisms. Therefore, inhibition of biofilm formation is an alternative therapeutic action to control MRSA infections. The present study revealed the non-antibacterial biofilm inhibitory potential of hesperidin against ATCC strain and clinical isolates of S. aureus. In addition, hesperidin treatment significantly impedes lipase, hemolysin, autolysin, autoaggregation and staphyloxanthin production. Reductions of staphyloxanthin production possibly increase the MRSA susceptibility rate to H2O2 oxidative stress condition. In gene expression study revealed the hesperidin treatment downregulated the biofilm-associated gene (sarA), polysaccharide intracellular adhesion gene (icaA and icaD), autolysin (altA), fibronectin-binding protein (fnbA and fnbB) and staphyloxanthin production (crtM). Molecular docking analysis predicted the ability of hesperidin to interact with SarA and CrtM proteins involved in biofilm formation and staphyloxanthin production in MRSA.

scholarly journals The Prevalence of Virulence Determinants and Antibiotic Resistance Patterns in Methicillin—Resistant Staphylococcus aureus in a Nursing Home in Poland

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 427
Author(s):  
Martyna Kasela ◽  
Agnieszka Grzegorczyk ◽  
Bożena Nowakowicz-Dębek ◽  
Anna Malm
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Variable Number Tandem Repeat ◽  
Multidrug Resistant ◽  
Variable Number ◽  
Pulse Field ◽  
Virulence Determinants ◽  
Gene Encoding ◽  
Methicillin Resistant ◽  
Pulse Field Gel Electrophoresis

Nursing homes (NH) contribute to the regional spread of methicillin-resistant Staphylococcus aureus (MRSA). Moreover, residents are vulnerable to the colonization and subsequent infection of MRSA etiology. We aimed at investigating the molecular and phenotypic characteristics of 21 MRSA collected from the residents and personnel in an NH (Lublin, Poland) during 2018. All MRSA were screened for 20 genes encoding virulence determinants (sea-see, eta, etb, tst, lukS-F-PV, eno, cna, ebpS, fib, bbp, fnbA, fnbB, icaADBC) and for resistance to 18 antimicrobials. To establish the relatedness and clonal complexes of MRSA in NH we applied multiple-locus variable-number tandem-repeat fingerprinting (MLVF), pulse field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. We identified four sequence types (ST) among two clonal complexes (CC): ST (CC22) known as EMRSA-15 as well as three novel STs—ST6295 (CC8), ST6293 (CC8) and ST6294. All tested MRSA were negative for sec, eta, etb, lukS-F-PV, bbp and ebpS genes. The most prevalent gene encoding toxin was sed (52.4%; n = 11/21), and adhesins were eno and fnbA (100%). Only 9.5% (n = 2/21) of MRSA were classified as multidrug-resistant. The emergence of novel MRSA with a unique virulence and the presence of epidemic clone EMRSA-15 creates challenges for controlling the spread of MRSA in NH.

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