Antimicrobial photodynamic therapy (aPDT) against vancomycin resistant Staphylococcus aureus (VRSA) biofilm disruption: a putative role of phagocytosis in infection control

Author(s):  
Farheen Akhtar ◽  
Asad U Khan
Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 869
Author(s):  
Beatriz Müller Nunes Souza ◽  
Juliana Guerra Pinto ◽  
André Henrique Correia Pereira ◽  
Alejandro Guillermo Miñán ◽  
Juliana Ferreira-Strixino

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine® (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm2. The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains.


2012 ◽  
Author(s):  
João Alves dos Reis Júnior ◽  
Patrícia Nascimento de Assis ◽  
Garde^nia Matos Paraguassú ◽  
Isabele Cardoso Vieira de de Castro ◽  
Renan Ferreira Trindade ◽  
...  

1996 ◽  
Vol 17 (8) ◽  
pp. 496-502 ◽  
Author(s):  
Didier Pittet ◽  
Edith Safran ◽  
Stephan Harbarth ◽  
François Borst ◽  
Pascale Copin ◽  
...  

AbstractBackground: Methicillin-resistant Staphylococcus aureus (MRSA) is an escalating problem in hospitals worldwide. The hospital reservoir for MRSA includes recognized and unrecognized colonized or infected patients, as well as previously colonized or infected patients readmitted to the hospital. Early and appropriate infection control measures (ICM) are key elements to reduce MRSA transmission and to control the hospital reservoir.Objective: To describe the role of an expert system applied to the control of MRSA at a large medical center (1,600 beds) with high endemic rates.Methods: The University Hospital of Geneva has an extended hospital information system (HIS), DIOGENE, structured with an open distributed architecture. It includes administrative, medical, nursing, and laboratory applications with their relational databases. Among available patient databases, clinical microbiology laboratory and admission-discharge-transfer (ADT) databases are used to generate computer alerts. A laboratory alert (lab alert) is printed daily in the Infection Control Program (ICP) offices, listing all patients with cultures positive for MRSA detected within the preceding 24 hours. Patients might be either newly detected patients colonized or infected with MRSA, or previously recognized MRSA patients having surveillance cultures. The ICP nurses subsequently go to the ward or call the ward personnel to implement ICM. A second alert, the “readmission alert,” detects readmission to the hospital of any patient previously colonized or infected with MRSA by periodic queries (q 1 min) to the ADT database. The readmission alert is printed in the ICP offices, but also forwarded with added guidelines to the emergency room.Results: During the first 12 months of application (July 1994 to June 1995), the lab alert detected an average of 4.6 isolates per day, corresponding to 314 hospital admissions (248 patients); the use of this alert saved time for the ICP nurses by improving work organization. There were 438 readmission alerts (1.2 alerts per day) over the study period; of 347 patients screened immediately upon readmission, 114 (33%) were positive for MRSA carriage. Delayed recognition of readmitted MRSA carriers decreased significantly after the implementation of this alert; the proportion of MRSA patients recognized at the time of admission to the hospital increased from 13% in 1993 to 40% in 1995 (P<.001).Conclusions: Hospital information system-based alerts can play an important role in the surveillance and early prevention of MRSA transmission, and it can help to recognize patterns of colonization and transmission.


2022 ◽  
pp. 201-277
Author(s):  
Mariana Q. Mesquita ◽  
Cristina J. Dias ◽  
Maria G. P. M. S. Neves ◽  
Adelaide Almeida ◽  
M. Amparo F. Faustino

2016 ◽  
Vol 13 ◽  
pp. 139-147 ◽  
Author(s):  
Fahim Vohra ◽  
Zohaib Akram ◽  
Syarida Hasnur Safii ◽  
Rathna Devi Vaithilingam ◽  
Alexis Ghanem ◽  
...  

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