Photoinactivation of Staphylococcus aureus using protoporphyrin IX: the role of haem-regulated transporter HrtA

Nakonieczna, Joanna; Kossakowska-Zwierucho, Monika; Filipiak, Michalina; Hewelt-Belka, Weronika; Grinholc, Mariusz; Bielawski, Krzysztof Piotr

doi:10.1007/s00253-015-7145-5

Cited by 13 publications

(17 citation statements)

References 45 publications

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“…S. aureus is not the only bacterial species that can express CSHRs enabling rapid hemin acquisition; indeed, studies aimed at elucidating the roles of specific heme transporters in aPDT are just now emerging. 45 To determine whether Ga-PpIX might be considered for targeted aPDT against additional pathogens, we developed a fluorescence imaging assay and screened a diverse panel of Gram-positive and negative bacteria for rapid Ga-PpIX uptake. Based on prior studies, 37 we expected bacteria to fall into three types: (1) those capable of rapid hemin acquisition via expression of CSHRs; (2) those that acquire hemin by the release and recovery of harvesting proteins (hemophores), 46 with a consequent delay in hemin acquisition rate; and (3) species that do not produce hemin-harvesting systems for iron acquisition (Figure 7).…”

Section: Resultsmentioning

confidence: 99%

Rapid Uptake and Photodynamic Inactivation of Staphylococci by Ga(III)-Protoporphyrin IX

et al. 2018

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Antimicrobial photodynamic therapy (aPDT) is a promising method for the topical treatment of drug-resistant staphylococcal infections and can be further improved by identifying mechanisms that increase the specificity of photosensitizer uptake by bacteria. Here we show that Ga(III)-protoporphyrin IX chloride (Ga-PpIX), a fluorescent hemin analog with previously undisclosed photosensitizing properties, can be taken up within seconds by Staphylococcus aureus including multidrug-resistant strains such as MRSA. The uptake of Ga-PpIX by staphylococci is likely diffusion-limited and is attributed to the expression of high-affinity cell-surface hemin receptors (CSHRs), namely iron-regulated surface determinant (Isd) proteins. A structure-activity study reveals the ionic character of both the heme center and propionyl groups to be important for uptake specificity. Ga-PpIX was evaluated as a photosensitizer against S. aureus and several clinical isolates of MRSA using a visible light source, with antimicrobial activity at 0.03 μM with 10 s of irradiation by a 405 nm diode array (1.4 J/cm); antimicrobial activity could also be achieved within minutes using a compact fluorescent lightbulb. GaPpIX was not only many times more potent than PpIX, a standard photosensitizer featured in clinical aPDI, but also demonstrated low cytotoxicity against HEK293 cells and human keratinocytes. Ga-PpIX uptake was screened against a diverse panel of bacterial pathogens using a fluorescence-based imaging assay, which revealed rapid uptake by several Gram-positive species known to express CSHRs, suggesting future candidates for targeted aPDT.

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Section: Resultsmentioning

confidence: 99%

Rapid Uptake and Photodynamic Inactivation of Staphylococci by Ga(III)-Protoporphyrin IX

et al. 2018

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“…While applying sublethal doses of aPDI, we have to not only ensure suitable aPDI treatment, i.e., the availability of a proper aPDI dose (PS concentration plus light dose), but also consider situations where many subpopulations of bacteria coexist within a single niche that may respond differently to aPDI. From the previous studies, we could tell that there were several bacterial features that influence the response to aPDI, e.g., superoxide dismutase activity 49 , membrane fluidity 50 , PS uptake 51 , and growth rate 52 . Some cells are exposed to sublethal doses due to insufficient availability of PS or light, whereas others cope better (or worse) due to all the intrinsic features mentioned above.…”

Section: Discussionmentioning

confidence: 99%

Validation of stable reference genes in Staphylococcus aureus to study gene expression under photodynamic treatment: a case study of SEB virulence factor analysis

Ogonowska

Nakonieczna

2020

Sci Rep

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Staphylococcal enterotoxin B (SEB), encoded by the seb gene, is a virulence factor produced by Staphylococcus aureus that is involved mainly in food poisoning and is known to act as an aggravating factor in patients with atopic dermatitis. Research results in animal infection models support the concept that superantigens, including SEB contribute to sepsis and skin and soft tissue infections. In contrast to antibiotics, antimicrobial photodynamic inactivation (aPDI) is a promising method to combat both bacterial cells and virulence factors. The main aims of this research were to (1) select the most stable reference genes under sublethal aPDI treatments and (2) evaluate the impact of aPDI on seb. Two aPDI combinations were applied under sublethal conditions: rose bengal (RB) and green light (λmax = 515 nm) and new methylene blue (NMB) and red light (λmax = 632 nm). The stability of ten candidate reference genes (16S rRNA, fabD, ftsZ, gmk, gyrB, proC, pyk, rho, rpoB and tpiA) was evaluated upon aPDI using four software packages—BestKeeper, geNorm, NormFinder and RefFinder. Statistical analyses ranked ftsZ and gmk (RB + green light) and ftsZ, proC, and fabD (NMB + red light) as the most stable reference genes upon photodynamic treatment. Our studies showed downregulation of seb under both aPDI conditions, suggesting that aPDI could decrease the level of virulence factors.

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“…The gene hemY , which was expressed in the oxic sunlight-exposed experiments ~6-fold more than in the dark controls, codes for a protoporphyrinogen oxidase and is involved in porphyrin metabolism. Porphyrins are well-known photosensitizers, and the use of synthetic or naturally occurring porphyrins for the enhancement of photoinactivation in applications like photodynamic therapy has been studied for many years (Jori and Brown, 2004 ; Ferro et al, 2007 ; Khlebtsov et al, 2013 ; Nakonieczna et al, 2016 ). Specifically, hemY catalyzes the oxidation of protoporphyrinogen (or coproporphyrinogen), yielding protoporphyrin (or coproporphyrin) and hydrogen peroxide.…”

Section: Discussionmentioning

confidence: 99%

Transcriptional Response of Staphylococcus aureus to Sunlight in Oxic and Anoxic Conditions

McClary

Boehm

2018

Front. Microbiol.

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The transcriptional response of Staphylococcus aureus strain Newman to sunlight exposure was investigated under both oxic and anoxic conditions using RNA sequencing to gain insight into potential mechanisms of inactivation. S. aureus is a pathogenic bacterium detected at recreational beaches which can cause gastrointestinal illness and skin infections, and is of increasing public health concern. To investigate the S. aureus photostress response in oligotrophic seawater, S. aureus cultures were suspended in seawater and exposed to full spectrum simulated sunlight. Experiments were performed under oxic or anoxic conditions to gain insight into the effects of oxygen-mediated and non-oxygen-mediated inactivation mechanisms. Transcript abundance was measured after 6 h of sunlight exposure using RNA sequencing and was compared to transcript abundance in paired dark control experiments. Culturable S. aureus decayed following biphasic inactivation kinetics with initial decay rate constants of 0.1 and 0.03 m2 kJ−1 in oxic and anoxic conditions, respectively. RNA sequencing revealed that 71 genes had different transcript abundance in the oxic sunlit experiments compared to dark controls, and 18 genes had different transcript abundance in the anoxic sunlit experiments compared to dark controls. The majority of genes showed reduced transcript abundance in the sunlit experiments under both conditions. Three genes (ebpS, NWMN_0867, and NWMN_1608) were found to have the same transcriptional response to sunlight between both oxic and anoxic conditions. In the oxic condition, transcripts associated with porphyrin metabolism, nitrate metabolism, and membrane transport functions were increased in abundance during sunlight exposure. Results suggest that S. aureus responds differently to oxygen-dependent and oxygen-independent photostress, and that endogenous photosensitizers play an important role during oxygen-dependent indirect photoinactivation.

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Photoinactivation of Staphylococcus aureus using protoporphyrin IX: the role of haem-regulated transporter HrtA

Cited by 13 publications

References 45 publications

Rapid Uptake and Photodynamic Inactivation of Staphylococci by Ga(III)-Protoporphyrin IX

Rapid Uptake and Photodynamic Inactivation of Staphylococci by Ga(III)-Protoporphyrin IX

Validation of stable reference genes in Staphylococcus aureus to study gene expression under photodynamic treatment: a case study of SEB virulence factor analysis

Transcriptional Response of Staphylococcus aureus to Sunlight in Oxic and Anoxic Conditions

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