Blue and red light photoemitters as approach to inhibit Staphylococcus aureus and Pseudomonas aeruginosa growth / Fotoemissores de luz azul e vermelha como abordagem para inibir o crescimento de Staphylococcus aureus e Pseudomonas aeruginosa

The ability of pathogenic bacteria acquire resistance to the existing antibiotics has long been considered a dangerous health risk threat. Currently, the use of visible light has been considered a new approach to treat bacterial infections as an alternative to antibiotics. Herein, we investigated the antimicrobial effect of two range of visible light, blue and red, on Staphylococcus aureus and Pseudomonas aeruginosa, two pathogenic bacterial commonly found in healthcare settings-acquired infections and responsible for high rate of morbidity and mortality. Bacterial cultures were exposed to blue or red light (470 nm and 660 nm) provided by light-emitting diodes - LED. The fluencies and irradiance used for blue and red light were 284.90 J/cm2, 13.19 mW/cm2 and 603.44 J/cm2, 27.93 mW/cm2 respectively. Different experimental approaches were used to determine the optimal conditions of light application. Only exposure to blue light for 6 hours was able to inhibit about 75% in vitro growth of both bacterial species after 24 hours. The surviving exposed bacteria formed colonies significantly smaller than controls, however, these bacteria were able to resume growth after 48 hours. Blue light was able to inhibit bacterial growth upon inoculation in both saline solution and BHI culture medium. We can conclude that blue light, but not red light, is capable of temporarily retarding the growth of gram negative and gram positive bacteria.

A capacidade das bactérias patogênicas adquirirem resistência aos antibióticos existentes há muito tempo é considerada uma ameaça perigosa à saúde. Atualmente, o uso da luz visível tem sido considerado uma nova abordagem no tratamento de infecções bacterianas como alternativa aos antibióticos. Neste trabalho, investigamos o efeito antimicrobiano de duas faixas de luz visível, azul e vermelha, em Staphylococcus aureus e Pseudomonas aeruginosa, duas bactérias patogênicas comumente encontradas em infecções adquiridas em instituições de saúde e responsáveis por alta taxa de morbimortalidade. As culturas bacterianas foram expostas à luz azul ou vermelha (470 nm e 660 nm) fornecida por diodos emissores de luz - LED. As fluências e irradiâncias utilizadas para luz azul e vermelha foram 284,90 J/cm2, 13,19 mW/cm2 e 603,44 J/cm2, 27,93 mW/cm2, respectivamente. Várias abordagens experimentais foram utilizadas para determinar as condições ótimas de aplicação da luz. Apenas a exposição à luz azul por 6 horas foi capaz de inibir cerca de 75% o crescimento in vitro de ambas as espécies bacterianas após 24 horas. As bactérias expostas sobreviventes formaram colônias com um tamanho significativamente menor do que os controles, contudo, essas bactérias conseguiram retomar o crescimento normal após 48 horas. A luz azul foi capaz de inibir o crescimento das bactérias após sua inoculação em solução salina ou no meio de cultura rico em nutrientes BHI. Podemos concluir que a luz azul mas não a luz vermelha é capaz de retardar temporariamente o crescimento de bactérias Gram-negativas e Gram-positivas.

Blue and red light photoemitters as approach to inhibit Staphylococcus aureus and Pseudomonas aeruginosa growth / Fotoemissores de luz azul e vermelha como abordagem para inibir o crescimento de Staphylococcus aureus e Pseudomonas aeruginosa

The ability of pathogenic bacteria acquire resistance to the existing antibiotics has long been considered a dangerous health risk threat. Currently, the use of visible light has been considered a new approach to treat bacterial infections as an alternative to antibiotics. Herein, we investigated the antimicrobial effect of two range of visible light, blue and red, on Staphylococcus aureus and Pseudomonas aeruginosa, two pathogenic bacterial commonly found in healthcare settings-acquired infections and responsible for high rate of morbidity and mortality. Bacterial cultures were exposed to blue or red light (470 nm and 660 nm) provided by light-emitting diodes - LED. The fluencies and irradiance used for blue and red light were 284.90 J/cm², 13.19 mW/cm² and 603.44 J/cm², 27.93 mW/cm² respectively. Different experimental approaches were used to determine the optimal conditions of light application. Only exposure to blue light for 6 hours was able to inhibit about 75% in vitro growth of both bacterial species after 24 hours. The surviving exposed bacteria formed colonies significantly smaller than controls, however, these bacteria were able to resume growth after 48 hours. Blue light was able to inhibit bacterial growth upon inoculation in both saline solution and BHI culture medium. We can conclude that blue light, but not red light, is capable of temporarily retarding the growth of gram negative and gram positive bacteria.

A capacidade das bactérias patogênicas adquirirem resistência aos antibióticos existentes há muito tempo é considerada uma ameaça perigosa à saúde. Atualmente, o uso da luz visível tem sido considerado uma nova abordagem no tratamento de infecções bacterianas como alternativa aos antibióticos. Neste trabalho, investigamos o efeito antimicrobiano de duas faixas de luz visível, azul e vermelha, em Staphylococcus aureus e Pseudomonas aeruginosa, duas bactérias patogênicas comumente encontradas em infecções adquiridas em instituições de saúde e responsáveis por alta taxa de morbimortalidade. As culturas bacterianas foram expostas à luz azul ou vermelha(470 nm e 660 nm) fornecida por diodos emissores de luz - LED. As fluências e irradiâncias utilizadas para luz azule vermelha foram 284,90 J/cm², 13,19 mW/cm² e 603,44 J/cm², 27,93 mW/cm², respectivamente. Várias abordagens experimentais foram utilizadas para determinar as condições ótimas de aplicação da luz. Apenas a exposição à luz azul por 6 horas foi capaz de inibir cerca de 75% o crescimento in vitro de ambas as espécies bacterianas após24 horas. As bactérias expostas sobreviventes formaram colônias com um tamanho significativamente menor do que os controles, contudo, essas bactérias conseguiram retomar o crescimento normal após 48 horas. A luz azul foi capaz de inibir o crescimento das bactérias após sua inoculação em solução salina ou no meio de cultura rico em nutrientes BHI. Podemos concluir que a luz azul mas não a luz vermelha é capaz de retardar temporariamente o crescimento de bactérias Gram-negativas e Gram-positivas.

Blue and red light photoemitters as approach to inhibit Staphylococcus aureus and Pseudomonas aeruginosa growth

Abstract The ability of pathogenic bacteria acquire resistance to the existing antibiotics has long been considered a dangerous health risk threat. Currently, the use of visible light has been considered a new approach to treat bacterial infections as an alternative to antibiotics. Herein, we investigated the antimicrobial effect of two range of visible light, blue and red, on Staphylococcus aureus and Pseudomonas aeruginosa, two pathogenic bacterial commonly found in healthcare settings-acquired infections and responsible for high rate of morbidity and mortality. Bacterial cultures were exposed to blue or red light (470 nm and 660 nm) provided by light-emitting diodes - LED. The fluencies and irradiance used for blue and red light were 284.90 J/cm2, 13.19 mW/cm2 and 603.44 J/cm2, 27.93 mW/cm2 respectively. Different experimental approaches were used to determine the optimal conditions of light application. Only exposure to blue light for 6 hours was able to inhibit about 75% in vitro growth of both bacterial species after 24 hours. The surviving exposed bacteria formed colonies significantly smaller than controls, however, these bacteria were able to resume growth after 48 hours. Blue light was able to inhibit bacterial growth upon inoculation in both saline solution and BHI culture medium. We can conclude that blue light, but not red light, is capable of temporarily retarding the growth of gram negative and gram positive bacteria.

Resumo A capacidade das bactérias patogênicas adquirirem resistência aos antibióticos existentes há muito tempo é considerada uma ameaça perigosa à saúde. Atualmente, o uso da luz visível tem sido considerado uma nova abordagem no tratamento de infecções bacterianas como alternativa aos antibióticos. Neste trabalho, investigamos o efeito antimicrobiano de duas faixas de luz visível, azul e vermelha, em Staphylococcus aureus e Pseudomonas aeruginosa, duas bactérias patogênicas comumente encontradas em infecções adquiridas em instituições de saúde e responsáveis por alta taxa de morbimortalidade. As culturas bacterianas foram expostas à luz azul ou vermelha (470 nm e 660 nm) fornecida por diodos emissores de luz - LED. As fluências e irradiâncias utilizadas para luz azul e vermelha foram 284,90 J/cm2, 13,19 mW/cm2 e 603,44 J/cm2, 27,93 mW/cm2, respectivamente. Várias abordagens experimentais foram utilizadas para determinar as condições ótimas de aplicação da luz. Apenas a exposição à luz azul por 6 horas foi capaz de inibir cerca de 75% o crescimento in vitro de ambas as espécies bacterianas após 24 horas. As bactérias expostas sobreviventes formaram colônias com um tamanho significativamente menor do que os controles, contudo, essas bactérias conseguiram retomar o crescimento normal após 48 horas. A luz azul foi capaz de inibir o crescimento das bactérias após sua inoculação em solução salina ou no meio de cultura rico em nutrientes BHI. Podemos concluir que a luz azul mas não a luz vermelha é capaz de retardar temporariamente o crescimento de bactérias Gram-negativas e Gram-positivas.

Possible therapeutic targets and promising drugs based on unsymmetrical hetaryl-substituted porphyrins to combat SARS-CoV-2 / 药物分析学报

Coronavirus disease 2019 is a serious disease that causes acute respiratory syndrome and negatively affects the central nervous system.Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)crosses the blood-brain barrier due to the spike (S) protein on the surface of the viral particles.Thus,it is important to develop compounds that not only have an inhibitory effect but are also capable of completely deactivating the S protein function.This study describes the purposeful modification of porphyrins and proposes compounds,asymmetrically hetaryl-substituted porphyrins with benzothia-zole,benzoxazole,and N-methylbenzimidazole residues,to deactivate the S protein functions.Molecular docking of SARS-CoV-2 proteins with hetaryl-substituted porphyrins showed that the viral S protein,nucleocapsid (N) protein,and non-structural protein 13 (nsp13) exhibited the highest binding affinity.Hetaryl-substituted porphyrins form strong complexes (13-14 kcal/mol) with the receptor-binding domain of the S protein,while the distance from the porphyrins to the receptor-binding motif (RBM)does not exceed 20 (A);therefore,RBM can be oxidized by 1O2,which is generated by porphyrin.Hetaryl-substituted porphyrins interact with the N protein in the serine/arginine-rich region,and a number of vulnerable amino acid residues are located in the photooxidation zone.This damage complicates the packaging of viral RNA into new virions.High-energy binding of hetaryl-substituted porphyrins with the N-and C-terminal domains of nsp13 was observed.This binding blocks the action of nsp13 as an enzyme of exoribonuclease and methyltransferase,thereby preventing RNA replication and processing.A pro-cedure for the synthesis of hetaryl-substituted porphyrins was developed,new compounds were ob-tained,their structures were identified,and their photocatalytic properties were studied.

Studies on Separation and Identification of the Components as well as the Tu- mor-photobiological Activities of the Major Components of Photocarcinorin / 第二军医大学学报

The chemical composition, separation and identification of the components as well as the tumor photobiological activities of the major components of the new tumor-photochemodiagnostic and photochemotherapeutic agent photocarcinorin (PsD-007) were represented in this paper. It has been shown by the results of HPLC analysis in combination with spectroscopic determinations that PsD-007 is composed of 7 different porphyrins: MHD, DMD, MVD, AHD, HVD, Hp and Pp. The experimental results show that MHD, DMD and MVD are the major tumor photobiologically active components of PsD-007.