Glycoprotein 340’s scavenger receptor cysteine-rich domain promotes adhesion of Staphylococcus aureus and Pseudomonas aeruginosa to contact lens polymers.

2021 ◽  
Author(s):  
Kwaku A. Osei ◽  
Joshua L. Mieher ◽  
Manisha Patel ◽  
Jason J. Nichols ◽  
Champion Deivanayagam

Contact lenses are biomaterials worn on the eye to correct refractive errors. Bacterial adhesion and colonization of these lenses results in adverse events such as microbial keratitis. The adsorption of tear proteins to contact lens materials enhances bacterial adhesion. Glycoprotein 340 (Gp340), a tear component, is known to promote microbial colonization in the oral cavity, however, it has not been investigated in any contact lens-related adverse event. Therefore, this study examined the adsorption of Gp340 and its recombinantly expressed scavenger receptor cysteine rich ( i SRCR 1 Gp340 ) domain on two common contact lens materials, etafilcon A and lotrafilcon B, and the concomitant effects on the adherence of clinical isolates of microbial keratitis causative agents, Pseudomonas aeruginosa (PA6206, PA6294), and Staphylococcus aureus (SA38, USA300). Across all strains and materials, i SRCR 1 Gp340 enhanced adherence of bacteria in a dose-dependent manner. However, i SRCR 1 Gp340 did not modulate lysozyme’s and lactoferrin’s effects on bacterial adhesion to the contact lens. The Gp340 binding surface protein SraP significantly enhanced USA300 binding to i SRCR 1 Gp340 -coated lenses. In addition, i SRCR 1 Gp340 -coated surfaces had significantly diminished biofilms with the SraP mutant (ΔSraP ), and with the Sortase A mutant (ΔSrtA ), there was a further reduction in biofilms, indicating the likely involvement of additional surface proteins. Finally, the binding affinities between i SRCR 1 Gp340 and SraP were determined using surface plasmon resonance (SPR), where the complete SraP binding region displayed nanomolar affinity, whereas its smaller fragments adhered with micromolar affinities. This study concludes that Gp340 and its SRCR domains play an important role in bacterial adhesion to the contact lens.

2021 ◽  
Vol 23 (1) ◽  
pp. 25-35
Author(s):  
Eghosasere Iyamu ◽  
Frederick Osaro Ekhaise

Purpose: The aim of this study was to investigate the adhesion of bacteria to worn silicone hydrogel and conventional soft contact lenses.Methods: Bacterial adhesion experiments / assays were performed on 24 worn and 6 unworn soft contact lenses each of different materials (high- and low- gas permeable lenses) using the strains such as Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 25923.Results: P. aeruginosa adhered in increased number to worn than unworn Lotrafilcon A and conventional lenses. However, a higher number of P. aeruginosa adhered to unworn than worn Lotrafilcon B, the difference in the mean adhesion was not significant (p = 0.66). S. aureus adhered in significantly decreased number to worn Lotrafilcon A, nelfilcon A, nesofilcon A, etafilcon A and omafilcon A (p<0.05); butsignificantly higher number adhered to worn than unworn polymacon (p<0.05). Lens wear had no effect on the adhesion of S. aureus to Lotrafilcon B (p>0.05). The least adhesion of P. aeruginosa to worn contact lenses was seen with polymacon, while S. aureus adhered in least number to worn Lotrafilcon A compared to the other contact lens materials that demonstrated the same trend in adhesion.Conclusion: The higher adhesion of P. aeruginosa to worn lenses is consistent with the claim that it is the most implicated in all culture-positive contact lens related bacterial keratitis. Lens wear has different effects on bacterial adhesion, which may be due to type of lens materials and bacterial species/genera studied. Keywords: Silicone hydrogel lenses, conventional lenses, Pseudomonas aeruginosa, Staphylococcus aureus, bacterial adhesion.


2016 ◽  
Vol 89 (3) ◽  
pp. 430-434 ◽  
Author(s):  
Madalina Anca Lazar ◽  
Dan Vodnar ◽  
Doina Prodan ◽  
Horatiu Rotaru ◽  
Calin Rares Roman ◽  
...  

Background and aims. Despite the fact that implants are sterilized, antiseptic techniques are applied and systemic antibiotics are routinely administered prior to and after craniofacial surgery, infection rates between 3% and 40% are still reported for alloplastic implants, urging for implant removal. The present study focuses on the development of a fiber-reinforced composite (FRC) implant for craniofacial reconstruction with antimicrobial properties.Methods. A new fiber-reinforced composite coated with gentamicin was developed and tested for bacterial adherence and antibacterial efficiency, using two of the most involved bacterial strains in the postoperative infections: Staphylococcus aureus and Pseudomonas aeruginosa.Results. Bacteria were efficiently inactivated in direct contact with gentamicin coatings (p<0.05). The inhibition zone for Staphylococcus aureus ranged from 17.21 mm to 20.13 mm and for Pseudomonas aeruginosa ranged from 12.93 mm to 15.33 mm. Although no significant statistical results were found for bacterial adhesion and gentamicin concentration, (Staphylococcus aureus: β= -0.974; p=0.144>0.05 and Pseudomonas aeruginosa: β = -0.921; p=0.255>0.05), a negative relation was observed, indicating the reversed relation between the antibiotic dosage and the bacterial adherence.Conclusion. The results of the two applied microbiological protocols used in the study suggested that gentamicin eluting coating inhibited not only the bacterial growth, but also led to a lower initial bacterial adhesion to the surface of the implant. Thus, antibiotic coating of craniofacial implants may reduce the infection rate related to reconstructive surgery.


2008 ◽  
Vol 191 (3) ◽  
pp. 832-843 ◽  
Author(s):  
Nekane Merino ◽  
Alejandro Toledo-Arana ◽  
Marta Vergara-Irigaray ◽  
Jaione Valle ◽  
Cristina Solano ◽  
...  

ABSTRACT The capacity of Staphylococcus aureus to form biofilms on host tissues and implanted medical devices is one of the major virulence traits underlying persistent and chronic infections. The matrix in which S. aureus cells are encased in a biofilm often consists of the polysaccharide intercellular adhesin (PIA) or poly-N-acetyl glucosamine (PNAG). However, surface proteins capable of promoting biofilm development in the absence of PIA/PNAG exopolysaccharide have been described. Here, we used two-dimensional nano-liquid chromatography and mass spectrometry to investigate the composition of a proteinaceous biofilm matrix and identified protein A (spa) as an essential component of the biofilm; protein A induced bacterial aggregation in liquid medium and biofilm formation under standing and flow conditions. Exogenous addition of synthetic protein A or supernatants containing secreted protein A to growth media induced biofilm development, indicating that protein A can promote biofilm development without being covalently anchored to the cell wall. Protein A-mediated biofilm formation was completely inhibited in a dose-dependent manner by addition of serum, purified immunoglobulin G, or anti-protein A-specific antibodies. A murine model of subcutaneous catheter infection unveiled a significant role for protein A in the development of biofilm-associated infections, as the amount of protein A-deficient bacteria recovered from the catheter was significantly lower than that of wild-type bacteria when both strains were used to coinfect the implanted medical device. Our results suggest a novel role for protein A complementary to its known capacity to interact with multiple immunologically important eukaryotic receptors.


Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 240 ◽  
Author(s):  
Adriana Vollaro ◽  
Anna Esposito ◽  
Eliana Pia Esposito ◽  
Raffaele Zarrilli ◽  
Annalisa Guaragna ◽  
...  

Pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1 (PYED-1), a heterocyclic corticosteroid derivative of deflazacort, exhibits broad-spectrum antibacterial activity against Gram-negative and Gram-positive bacteria. Here, we investigated the effect of PYED-1 on the biofilms of Staphylococcus aureus, an etiological agent of biofilm-based chronic infections such as osteomyelitis, indwelling medical device infections, periodontitis, chronic wound infections, and endocarditis. PYED-1 caused a strong reduction in biofilm formation in a concentration dependent manner. Furthermore, it was also able to completely remove the preformed biofilm. Transcriptional analysis performed on the established biofilm revealed that PYED-1 downregulates the expression of genes related to quorum sensing (agrA, RNAIII, hld, psm, and sarA), surface proteins (clfB and fnbB), secreted toxins (hla, hlb, and lukD), and capsular polysaccharides (capC). The expression of genes that encode two main global regulators, sigB and saeR, was also significantly inhibited after treatment with PYED-1. In conclusion, PYED-1 not only effectively inhibited biofilm formation, but also eradicated preformed biofilms of S. aureus, modulating the expression of genes related to quorum sensing, surface and secreted proteins, and capsular polysaccharides. These results indicated that PYED-1 may have great potential as an effective antibiofilm agent to prevent S. aureus biofilm-associated infections.


2020 ◽  
Vol 30 (12) ◽  
pp. 1783-1787
Author(s):  
Bartosz Ditkowski ◽  
Kirsten Leeten ◽  
Ramadan Jashari ◽  
Elizabeth Jones ◽  
Ruth Heying

AbstractObjective:Infective endocarditis remains a severe complication associated with a high morbidity and mortality in patients after heart valve replacement. Exploration of the pathogenesis is of high demand and we, therefore, present a competent model that allows studying bacterial adherence and the role of plasma fibrinogen in this process using a new in-house designed low-volume flow chamber. Three cardiac graft tissues used for pulmonary valve replacement have been tested under shear conditions to investigate the impact of surface composition on the adhesion events.Methods:Tissue pieces of cryopreserved homograft (non-decellularised), decellularised homograft and bovine pericardium patch were investigated for fibrinogen binding. Adherence of Staphylococcus aureus to these graft tissues was studied quantitatively under flow conditions in our newly fabricated chamber based on a parallel plates’ modality. The method of counting colony-forming units was reliable and reproducible to assess the propensity of different graft materials for bacterial attachment under shear.Results:Bacterial perfusions over all plasma-precoated tissues identified cryopreserved homograft with the lowest affinity for S. aureus compared to decellularised homograft presenting a significantly higher bacterial adhesion (p < 0.05), which was linked to a more avid fibrinogen binding (p < 0.01). Bovine pericardial patch, as a reference tissue in this study, was confirmed to be the most susceptible tissue graft for the bacterial adhesion, which was in line with our previous work.Conclusion:The two studied homograft tissues showed different levels of bacterial attachment, which might be postulated by the involvement of fibrinogen in the adhesion mechanism(s) shown previously for bovine tissues.


2020 ◽  
Vol 73 (5) ◽  
pp. 261-266
Author(s):  
Sahra Kırmusaoğlu ◽  
Havva Kaşıkçı

AimsStaphylococcus aureus (S. aureus) is a life-threatening pathogen with high morbidity and mortality rates which causes nosocomial and community-acquired infections. Biofilm, considered to be a common virulence factor for pathogens, plays a significant role in recurrent and untreatable infections. Biofilm formation of S. aureus is mediated by synthesis of either poly-N-acetylglucosamine in an ica-dependent manner or surface proteins in an ica-independent manner. In some cases treatment is impossible and recurrent. In this study, ica-dependent biofilm-producing S. aureus isolates were detected and the anti-biofilm effect of ascorbic acid against biofilm formation of isolates was investigated.MethodsA total of 21 methicillin-sensitive S. aureus (MSSA) clinical isolates stored in our bacterial stock were used to detect ica-dependent biofilm-producing MSSA isolates. The anti-biofilm study was undertaken with three ica-dependent biofilm-producing isolates (MSSA2–4) and ATCC 29213 (MSSA1). Biofilms and the anti-biofilm effect of ascorbic acid were detected using the microtitre plate (MtP) method. 16S-rRNA, nuc, icaA and icaD genes and expression levels of icaA and icaD of isolates were detected by RT-PCR.ResultsThe minimum inhibitory concentrations (MICs) of ascorbic acid prevented biofilm formation of MSSA1 and MSSA3. Also, 1/2 MIC of ascorbic acid prevented biofilm formation of MSSA3. It was observed that biofilm formation decreased with increased concentration. There was no significant increase in ica gene expression of MSSA1 and MSSA2. Expression of icaA and icaD of MSSA3 decreased 13% and 38%, respectively. Expression of icaA in MSSA4 decreased 12%.ConclusionThe results of our study show that ascorbic acid can be used as an anti-biofilm agent to prevent biofilm formation of S. aureus and thus biofilm-related infections.


2016 ◽  
Vol 60 (7) ◽  
pp. 4259-4263 ◽  
Author(s):  
Leo Lin ◽  
Janie Kim ◽  
Hope Chen ◽  
Regis Kowalski ◽  
Victor Nizet

ABSTRACTMore than 125 million people wear contact lenses worldwide, and contact lens use is the single greatest risk factor for developing microbial keratitis. We tested the antibacterial activity of multipurpose contact lens solutions and their individual component preservatives against the two most common pathogens causing bacterial keratitis,Pseudomonas aeruginosaandStaphylococcus aureus. Thein vitroantibacterial activity of five multipurpose contact lens solutions (Opti-Free GP, Boston Simplus, Boston Advance, Menicare GP, and Lobob) was assayed by the standard broth dilution method. Synergy between the preservative components found in the top performing solutions was assayed using checkerboard and time-kill assays. The ISO 14729 criteria and the standard broth dilution method were used to define an optimized contact lens solution formulation against a clinical panel of drug-susceptible and drug-resistantP. aeruginosaandS. aureusstrains. Preservatives with the biguanide function group, chlorhexidine and polyaminopropylbiguanide (PAPB), had the best antistaphylococcal activity, while EDTA was the best antipseudomonal preservative. The combination of chlorhexidine and EDTA had excellent synergy againstP. aeruginosa. A solution formulation containing chlorhexidine (30 ppm), PAPB (5 ppm), and EDTA (5,000 ppm) had three to seven times more antipseudomonal activity than anything available to consumers today. A multipurpose contact lens solution containing a combination of chlorhexidine, PAPB, and EDTA could help to reduce the incidence of microbial keratitis for contact lens users worldwide.


2009 ◽  
Vol 2009 ◽  
pp. 1-3 ◽  
Author(s):  
Benoit Hue ◽  
Marc Doat ◽  
Gilles Renard ◽  
Marie-Laure Brandely ◽  
François Chast

Purpose. To report a case of microbial keratitis caused by Pseudomonas aeruginosa treated with a combination of acetazolamide and ceftazidime.Methods. Case report.Results. We report the case of a 17-year-old contact lens-wearing female who developed severe keratitis due toPseudomonas aeruginosatemporarily healed with topical fortified antibiotic eye drops. After few days, the patient relapsed, and topical and intravenous ceftazidime were added. Concomitantly, oral administration of acetazolamide was prescribed. This carbonic anhydrase inhibitor was added to the antibiotic regimen in order to decrease the anterior chamber pH, and then, the ceftazidime ionization. By lowering the state of ionization of the antibiotic in the aqueous humor, its concentration was increased. This was confirmed by an improvement of the patient within few days and a rapid eradication of the infection.Conclusion. This is the first reported case of keratitis caused byP. aeruginosasuccessfully treated using acetazolamide as an enhancer of ceftazidime effectiveness.


2021 ◽  
Vol 4 (2) ◽  
pp. 39-49
Author(s):  
Fatma Kalaycı-Yüksek ◽  
Defne Gümüş ◽  
Mine Anğ-Küçüker

Abstract Pseudomonas aeruginosa and Staphylococcus aureus are known as important nosocomial infectious agents also their co-infections are commonly seen in some patient groups. It is well known that host factors such as hormones have roles in modulation of growth, pathogenesis and susceptibilities to antimicrobials. In our study, the influences of norepinephrine (NE) and melatonin (MEL) on antibiotic susceptibilities were examined in mono and co-culture conditions. Methicilin resistant Staphylococcus aureus (MRSA) ATCC 43300 and Pseudomonas aeruginosa ATCC 27853 were investigated to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of ciprofloxacin and gentamicin in the absence/presence of NE (0.0017 and 0.04μg/mL) and MEL (6 and 60 pg/mL) by microdilution method in mono and co-culture. It was found that hormones decreased (among 2-64 fold) MIC and MBC values of both antibiotics for MRSA. However, it was shown that hormones had no effect on MIC values of both antibiotics for P. aeruginosa. MIC and MBC values of both antibiotics for co-culture were found to be reduced compared to monoculture of MRSA; were found to be increased compared to monoculture of P. aeruginosa. Whereas, hormones decreased MIC values of both antibiotics in co-culture conditions. Our results suggest that both hormones decreased MIC values and it seems that hormones could influence antibiotic susceptibilities in a strain-dependent manner.


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