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Cabral FV, dos Santos Souza TH, Sellera FP, Fontes A, Ribeiro MS. Strengthening collaborations at the Biology-Physics interface: trends in antimicrobial photodynamic therapy. Biophys Rev 2023; 15:685-697. [PMID: 37681106 PMCID: PMC10480098 DOI: 10.1007/s12551-023-01066-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/23/2023] [Indexed: 09/09/2023] Open
Abstract
The unbridled use of antimicrobial drugs over the last decades contributed to the global dissemination of drug-resistant pathogens and increasing rates of life-threatening infections for which limited therapeutic options are available. Currently, the search for safe, fast, and effective therapeutic strategies to combat infectious diseases is a worldwide demand. Antimicrobial photodynamic therapy (APDT) rises as a promising therapeutic approach against a wide range of pathogenic microorganisms. APDT combines light, a photosensitizing drug (PS), and oxygen to kill microorganisms by oxidative stress. Since the APDT field involves branches of biology and physics, the strengthening of interdisciplinary collaborations under the aegis of biophysics is welcome. Given this scenario, Brazil is one of the global leaders in the production of APDT science. In this review, we provide detailed reports of APDT studies published by the Laboratory of Optical Therapy (IPEN-CNEN), Group of Biomedical Nanotechnology (UFPE), and collaborators over the last 10 years. We present an integrated perspective of APDT from basic research to clinical practice and highlight its promising use, encouraging its adoption as an effective and safe technology to tackle important pathogens. We cover the use of methylene blue (MB) or Zn(II) porphyrins as PSs to kill bacteria, fungi, parasites, and pathogenic algae in laboratory assays. We describe the impact of MB-APDT in Dentistry and Veterinary Medicine to treat different infectious diseases. We also point out future directions combining APDT and nanotechnology. We hope this review motivates further APDT studies providing intuitive, vivid, and insightful information for the readers.
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Affiliation(s)
- Fernanda Viana Cabral
- Center for Lasers and Applications, Nuclear and Energy Research Institute (IPEN-CNEN), São Paulo, Brazil
| | | | - Fábio Parra Sellera
- Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
- School of Veterinary Medicine, Metropolitan University of Santos, Santos, Brazil
| | - Adriana Fontes
- Department of Biophysics and Radiobiology, Federal University of Pernambuco (UFPE), Recife, PE 50670-901 Brazil
| | - Martha Simões Ribeiro
- Center for Lasers and Applications, Nuclear and Energy Research Institute (IPEN-CNEN), São Paulo, Brazil
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2
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Piksa M, Lian C, Samuel IC, Pawlik KJ, Samuel IDW, Matczyszyn K. The role of the light source in antimicrobial photodynamic therapy. Chem Soc Rev 2023; 52:1697-1722. [PMID: 36779328 DOI: 10.1039/d0cs01051k] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Antimicrobial photodynamic therapy (APDT) is a promising approach to fight the growing problem of antimicrobial resistance that threatens health care, food security and agriculture. APDT uses light to excite a light-activated chemical (photosensitiser), leading to the generation of reactive oxygen species (ROS). Many APDT studies confirm its efficacy in vitro and in vivo against bacteria, fungi, viruses and parasites. However, the development of the field is focused on exploring potential targets and developing new photosensitisers. The role of light, a crucial element for ROS production, has been neglected. What are the main parameters essential for effective photosensitiser activation? Does an optimal light radiant exposure exist? And finally, which light source is best? Many reports have described the promising antibacterial effects of APDT in vitro, however, its application in vivo, especially in clinical settings remains very limited. The restricted availability may partially be due to a lack of standard conditions or protocols, arising from the diversity of selected photosensitising agents (PS), variable testing conditions including light sources used for PS activation and methods of measuring anti-bacterial activity and their effectiveness in treating bacterial infections. We thus sought to systematically review and examine the evidence from existing studies on APDT associated with the light source used. We show how the reduction of pathogens depends on the light source applied, radiant exposure and irradiance of light used, and type of pathogen, and so critically appraise the current state of development of APDT and areas to be addressed in future studies. We anticipate that further standardisation of the experimental conditions will help the field advance, and suggest key optical and biological parameters that should be reported in all APDT studies. More in vivo and clinical studies are needed and are expected to be facilitated by advances in light sources, leading to APDT becoming a sustainable, alternative therapeutic option for bacterial and other microbial infections in the future.
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Affiliation(s)
- Marta Piksa
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Science, Weigla 12, 53-114, Wroclaw, Poland
| | - Cheng Lian
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, Fife, KY16 9SS, UK.
| | - Imogen C Samuel
- School of Medicine, University of Manchester, Manchester, M13 9PL, UK
| | - Krzysztof J Pawlik
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Science, Weigla 12, 53-114, Wroclaw, Poland
| | - Ifor D W Samuel
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, Fife, KY16 9SS, UK.
| | - Katarzyna Matczyszyn
- Institute of Advanced Materials, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw, Poland.
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González-Martín M, Silva V, Poeta P, Corbera JA, Tejedor-Junco MT. Microbiological aspects of osteomyelitis in veterinary medicine: drawing parallels to the infection in human medicine. Vet Q 2022; 42:1-11. [PMID: 34936853 PMCID: PMC8725753 DOI: 10.1080/01652176.2021.2022244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/22/2021] [Accepted: 12/20/2021] [Indexed: 11/29/2022] Open
Abstract
Osteomyelitis is a challenging infectious disease affecting humans and animals. It is difficult to diagnose because, in many cases, symptoms are non-specific and, for example in implant-related cases, can appear long time after surgery. In addition to this, it is also difficult to treat due to the need to find the appropriate antibiotic regime and delivery system to reach the site of infection and to avoid development of bacterial resistance. The central purpose of this review is to compare the microbiological aspects of osteomyelitis in human and veterinary medicine, with the aim of improving the microbiological diagnosis and treatment of this infection in animals. Furthermore, the study of osteomyelitis in animals may help to improve the development of animal models for testing new treatments in humans. Host factors and underlying conditions have been studied mainly in humans, although aspects as immunodeficiency have been described in some veterinary cases. Even when Staphylococcus aureus is still considered the most prevalent causing microorganism, this prevalence should be reviewed using molecular diagnostic techniques, and this could affect treatment options. New approaches to treatment include local delivery of antibiotics using different biomaterials, antimicrobial photodynamic therapy, and new antimicrobial compounds. We would like to remark the need of large, high-quality clinical trials and of the development of guides for the diagnosis and treatment of osteomyelitis in different animal species.
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Affiliation(s)
- Margarita González-Martín
- Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain
- Department of Clinical Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain
| | - Vanessa Silva
- Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
- Associated Laboratory for Green Chemistry (LAQV-REQUIMTE), University NOVA of Lisboa, Caparica, Portugal
- Veterinary and Animal Research Centre, Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Patricia Poeta
- Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
- Associated Laboratory for Green Chemistry (LAQV-REQUIMTE), University NOVA of Lisboa, Caparica, Portugal
- Veterinary and Animal Research Centre, Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal
| | - Juan Alberto Corbera
- Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain
- Department of Animal Pathology, Animal Production and Food Science and Technology, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain
| | - María Teresa Tejedor-Junco
- Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain
- Department of Clinical Sciences, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Canary Islands, Spain
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Machado CS, Seeger MG, Moreira KS, Burgo TAL, Iglesias BA, Vogel FSF, Cargnelutti JF. In vitro porphyrin-based photodynamic therapy against mono and polyculture of multidrug-resistant bacteria isolated from integumentary infections in animals. Photodiagnosis Photodyn Ther 2022; 40:103179. [PMID: 36334907 DOI: 10.1016/j.pdpdt.2022.103179] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/19/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022]
Abstract
Multidrug-resistant (MDR) organisms have been frequently isolated from integumentary lesions of animals, and these lesions are usually infected by more than one pathogen. This study evaluated an in vitro antimicrobial photodynamic therapy (aPDT) using two water-soluble tetra-cationic porphyrins (3-H2TMeP and 4-H2TMeP) against mono and polyculture of MDR bacteria isolated from dogs, cats, and horses. Ten isolates of MDR bacteria (two of each species: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus pseudointermedius) were used to evaluate aPDT against the monoculture using a non-cytotoxic concentration of 3-H2TMeP and 4-H2TMeP porphyrins (40 µM), with 30 min of light irradiation in Gram-positive and 90 min for Gram-negative bacteria. The aPDT using the 4-H2TMeP porphyrin was also tested against five different polycultures (Coagulase positive Staphylococcus (CPS) and Pseudomonas sp.; E. coli and Proteus sp.; Pseudomonas sp. and Proteus sp.; CPS and E. coli; and CPS and Proteus sp.) for 90 min. The efficacy of both treatments was evaluated by plating the solution exposed to light or kept in the dark and counting the colonies forming units after 24 h of incubation at 37 °C. Atomic force microscope analysis was used to map bacteria morphological changes and extract adhesion force parameters from the bacteria membranes. Only the 4-H2TMeP porphyrin had antibacterial activity against MDR bacteria in monoculture, especially S. pseudointermedius and P. aeruginosa. In polyculture, the 4-H2TMeP porphyrin reduced bacterial concentrations (p < 0.05) in the associations of E. coli and S. pseudointermedius, P. aeruginosa and S. pseudointermedius, and P. aeruginosa and P. mirabilis. These results showed that aPDT using 4-H2TMeP is a good option for future associations of aPDT and other therapies or in vivo research.
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Affiliation(s)
- Carolina S Machado
- Programa de Pós-graduação em Medicina Veterinária (PPGMV) - Av. Roraima, Universidade Federal de Santa Maria (UFSM), 1000, prédio 97 - HVU, bairro Camobi, Santa Maria, RS CEP 97105-900, Brazil
| | - Marlane G Seeger
- Programa de Pós-graduação em Medicina Veterinária (PPGMV) - Av. Roraima, Universidade Federal de Santa Maria (UFSM), 1000, prédio 97 - HVU, bairro Camobi, Santa Maria, RS CEP 97105-900, Brazil
| | - Kelly S Moreira
- Coulomb Electrostatic and Mechanochemical Laboratory, Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Campus Camobi, Santa Maria, RS CEP 97105-900, Brazil
| | - Thiago A L Burgo
- Coulomb Electrostatic and Mechanochemical Laboratory, Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Campus Camobi, Santa Maria, RS CEP 97105-900, Brazil; Department of Chemistry and Environmental Sciences, Ibilce, São Paulo state University (Unesp), São José do Rio Preto, São Paulo, Brazil
| | - Bernardo A Iglesias
- Laboratório de Bioinorgânica e Materiais Porfirínicos - Departamento de Química, Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Campus Camobi, Santa Maria, RS CEP 97105-900, Brazil.
| | - Fernanda S F Vogel
- Departamento de Medicina Veterinária Preventiva (DMVP) - Av. Roraima, Universidade Federal de Santa Maria (UFSM), 1000, prédio 63D - bairro Camobi, Santa Maria, RS CEP 97105-900, Brazil
| | - Juliana F Cargnelutti
- Departamento de Medicina Veterinária Preventiva (DMVP) - Av. Roraima, Universidade Federal de Santa Maria (UFSM), 1000, prédio 63D - bairro Camobi, Santa Maria, RS CEP 97105-900, Brazil.
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Valandro P, Massuda MB, Rusch E, Birgel DB, Pereira PPL, Sellera FP, Ribeiro MS, Pogliani FC, Birgel Junior EH. Antimicrobial photodynamic therapy can be an effective adjuvant for surgical wound healing in cattle. Photodiagnosis Photodyn Ther 2021; 33:102168. [PMID: 33497814 DOI: 10.1016/j.pdpdt.2020.102168] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 01/28/2023]
Abstract
BACKGROUND Rumenostomy is a useful procedure commonly performed in cattle for medical treatment of domestic ruminants with forestomach diseases. Methylene blue (MB)-mediated antimicrobial photodynamic therapy (APDT) has been broadly investigated to treat infected wounds. AIM The aim of the study was to evaluate the effectiveness of MB-mediated APDT (MB-APDT) combined with chlorhexidine and zinc oxide ointment on wound healing process after rumenostomy. METHODS Fourteen Nelore bulls were subjected to rumenostomy procedure. Animals were randomly divided into MB-APDT (MB associated with a red diode laser performed immediately after surgery and repeated on days 3, 5, 7 and 10) and control groups. Daily care included topical cleaning with chlorhexidine 2% followed by topical zinc oxide ointment. Animals were followed-up until the 28th day. RESULTS Wounds presented a better post-surgical profile in MB-APDT group when it was compared with the control group. In MB-APDT group, it was also possible to observe less pain on palpation of wounds borders, less edema and inflammatory exudate. Additionally, animals from MB-APDT group were faster discharged from the cattle care facility. CONCLUSION Our results support the use of MB-APDT for the post-surgical management of rumenostomy. This pilot study ratifies the use of APDT in cattle and also suggests that it could be performed for other surgical procedures as a complementary approach or an alternative for topical administration of antibiotics.
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Affiliation(s)
- Patrícia Valandro
- Department of Veterinary Medicine, School of Animal Science and Food Engineering University of São Paulo, Pirassununga, Brazil
| | - Mayara B Massuda
- Department of Veterinary Medicine, School of Animal Science and Food Engineering University of São Paulo, Pirassununga, Brazil
| | - Elidiane Rusch
- Department of Veterinary Medicine, School of Animal Science and Food Engineering University of São Paulo, Pirassununga, Brazil
| | - Daniela B Birgel
- Department of Veterinary Medicine, School of Animal Science and Food Engineering University of São Paulo, Pirassununga, Brazil
| | - Philipe P L Pereira
- Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Fábio P Sellera
- Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil; School of Veterinary Medicine, Metropolitan University of Santos, Santos, Brazil
| | - Martha S Ribeiro
- Center for Lasers and Applications, Nuclear, and Energy Research Institute, National Commission for Nuclear Energy, São Paulo, SP, Brazil
| | - Fabio C Pogliani
- Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Eduardo H Birgel Junior
- Department of Veterinary Medicine, School of Animal Science and Food Engineering University of São Paulo, Pirassununga, Brazil.
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Validation of stable reference genes in Staphylococcus aureus to study gene expression under photodynamic treatment: a case study of SEB virulence factor analysis. Sci Rep 2020; 10:16354. [PMID: 33004977 PMCID: PMC7530716 DOI: 10.1038/s41598-020-73409-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/14/2020] [Indexed: 12/27/2022] Open
Abstract
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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Toledo VH, Yoshimura TM, Pereira ST, Castro CE, Ferreira FF, Ribeiro MS, Haddad PS. Methylene blue-covered superparamagnetic iron oxide nanoparticles combined with red light as a novel platform to fight non-local bacterial infections: A proof of concept study against Escherichia coli. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 209:111956. [PMID: 32673883 DOI: 10.1016/j.jphotobiol.2020.111956] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 01/25/2023]
Abstract
Currently, antimicrobial photodynamic therapy (APDT) is limited to the local treatment of topical infections, and a platform that can deliver the photosensitizer to internal organs is highly desirable for non-local ones; SPIONs can be promising vehicles for the photosensitizer. This work reports an innovative application of methylene blue (MB)-superparamagnetic iron oxide nanoparticles (SPIONs). We report on the preparation, characterization, and application of MB-SPIONs for antimicrobial photodynamic therapy. When exposed to light, the MB photosensitizer generates reactive oxygen species (ROS), which cause irreversible damage in microbial cells. We prepare SPIONs by the co-precipitation method. We cover the nanoparticles with a double silica layer - tetraethyl orthosilicate and sodium silicate - leading to the hybrid material magnetite-silica-MB. We characterize the as-prepared SPIONs by Fourier transform infrared spectroscopy, powder X-ray diffraction, and magnetic measurements. We confirm the formation of magnetite using powder X-ray diffraction data. We use the Rietveld method to calculate the average crystallite size of magnetite as being 14 nm. Infrared spectra show characteristic bands of iron‑oxygen as well as others associated with silicate groups. At room temperature, the nanocomposites present magnetic behavior due to the magnetite core. Besides, magnetite-silica-MB can promote ROS formation. Thus, we evaluate the photodynamic activity of Fe3O4-silica-MB on Escherichia coli. Our results show the bacteria are completely eradicated following photodynamic treatment depending on the MB release time from SPIONs and energy dose. These findings encourage us to explore the use of magnetite-silica-MB to fight internal infections in preclinical assays.
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Affiliation(s)
- Victor Hladkyi Toledo
- Department of Chemistry, Federal University of São Paulo (UNIFESP), 09961-400 Diadema, SP, Brazil
| | - Tania Mateus Yoshimura
- Center for Laser and Applications, Energy and Nuclear Research Institute (IPEN), 05508-000 São Paulo, SP, Brazil
| | - Saulo Toledo Pereira
- Center for Laser and Applications, Energy and Nuclear Research Institute (IPEN), 05508-000 São Paulo, SP, Brazil
| | - Carlos Eduardo Castro
- Center for Natural and Human Sciences (CCNH), Federal University of ABC (UFABC), 09210-580 Santo André, SP, Brazil
| | - Fabio Furlan Ferreira
- Center for Natural and Human Sciences (CCNH), Federal University of ABC (UFABC), 09210-580 Santo André, SP, Brazil
| | - Martha Simões Ribeiro
- Center for Laser and Applications, Energy and Nuclear Research Institute (IPEN), 05508-000 São Paulo, SP, Brazil
| | - Paula Silvia Haddad
- Department of Chemistry, Federal University of São Paulo (UNIFESP), 09961-400 Diadema, SP, Brazil.
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Identification of Reptarenaviruses, Hartmaniviruses, and a Novel Chuvirus in Captive Native Brazilian Boa Constrictors with Boid Inclusion Body Disease. J Virol 2020; 94:JVI.00001-20. [PMID: 32238580 DOI: 10.1128/jvi.00001-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 03/20/2020] [Indexed: 01/03/2023] Open
Abstract
Boid inclusion body disease (BIBD) is a transmissible viral disease of captive snakes that causes severe losses in snake collections worldwide. It is caused by reptarenavirus infection, which can persist over several years without overt signs but is generally associated with the eventual death of the affected snakes. Thus far, reports have confirmed the existence of reptarenaviruses in captive snakes in North America, Europe, Asia, and Australia, but there is no evidence that it also occurs in wild snakes. BIBD affects boa species within the subfamily Boinae and pythons in the family Pythonidae, the habitats of which do not naturally overlap. Here, we studied Brazilian captive snakes with BIBD using a metatranscriptomic approach, and we report the identification of novel reptarenaviruses, hartmaniviruses, and a new species in the family Chuviridae The reptarenavirus L segments identified are divergent enough to represent six novel species, while we found only a single novel reptarenavirus S segment. Until now, hartmaniviruses had been identified only in European captive boas with BIBD, and the present results increase the number of known hartmaniviruses from four to six. The newly identified chuvirus showed 38.4%, 40.9%, and 48.1% amino acid identity to the nucleoprotein, glycoprotein, and RNA-dependent RNA polymerase, respectively, of its closest relative, Guangdong red-banded snake chuvirus-like virus. Although we cannot rule out the possibility that the found viruses originated from imported snakes, the results suggest that the viruses could circulate in indigenous snake populations.IMPORTANCE Boid inclusion body disease (BIBD), caused by reptarenavirus infection, affects captive snake populations worldwide, but the reservoir hosts of reptarenaviruses remain unknown. Here, we report the identification of novel reptarenaviruses, hartmaniviruses, and a chuvirus in captive Brazilian boas with BIBD. Three of the four snakes studied showed coinfection with all three viruses, and one of the snakes harbored three novel reptarenavirus L segments and one novel S segment. The samples originated from collections with Brazilian indigenous snakes only, which could indicate that these viruses circulate in wild snakes. The findings could further indicate that boid snakes are the natural reservoir of reptarena- and hartmaniviruses commonly found in captive snakes. The snakes infected with the novel chuvirus all suffered from BIBD; it is therefore not possible to comment on its potential pathogenicity and contribution to the observed changes in the present case material.
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Valenzuela-Valderrama M, González IA, Palavecino CE. Photodynamic treatment for multidrug-resistant Gram-negative bacteria: Perspectives for the treatment of Klebsiella pneumoniae infections. Photodiagnosis Photodyn Ther 2019; 28:256-264. [PMID: 31505296 DOI: 10.1016/j.pdpdt.2019.08.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 08/09/2019] [Indexed: 12/25/2022]
Abstract
The emergence of multi-drug resistance for pathogenic bacteria is one of the most pressing global threats to human health in the 21st century. Hence, the availability of new treatment becomes indispensable to prevent morbidity and mortality caused by infectious agents. This article reviews the antimicrobial properties of photodynamic therapy (PDT), which is based on the use of photosensitizers compounds (PSs). The PSs are non-toxic small molecules, which induce oxidative stress only under excitation with light. Then, the PDT has the advantage to be locally activated using phototherapy devices. We focus on PDT for the Klebsiella pneumoniae, as an example of Gram-negative bacteria, due to its relevance as an agent of health-associated infections (HAI) and a multi-drug resistant bacteria. K. pneumoniae is a fermentative bacillus, member of the Enterobacteriaceae family, which is most commonly associated with producing infection of the urinary tract (UTI) and pneumonia. K. pneumoniae infections may occur in deep organs such as bladder or lungs tissues; therefore, activating light must get access or penetrate tissues with sufficient power to produce effective PDT. Consequently, the rationale for selecting the most appropriate PSs, as well as photodynamic devices and photon fluence doses, were reviewed. Also, the mechanisms by which PDT activates the immune system and its importance to eradicate the infection successfully, are discussed.
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Affiliation(s)
- Manuel Valenzuela-Valderrama
- Laboratorio de Microbiología Celular, Instituto de Investigación e Innovación en Salud, Facultad de Ciencias de la Salud, Universidad Central de Chile, Chile; Centro de Estudios Avanzados en Enfermedades Crónicas (ACCDiS), Independencia, Santiago 8380000, Chile.
| | - Iván Alonzo González
- Instituto de Investigación e Innovación en Salud, Facultad de Ciencias de la Salud, Universidad Central de Chile, Chile.
| | - Christian Erick Palavecino
- Laboratorio de Microbiología Celular, Instituto de Investigación e Innovación en Salud, Facultad de Ciencias de la Salud, Universidad Central de Chile, Chile.
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Abstract
The emergence of antimicrobial drug resistance requires development of alternative therapeutic options. Multidrug-resistant strains of Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa and Enterobacter spp. are still the most commonly identified antimicrobial-resistant pathogens. These microorganisms are part of the so-called 'ESKAPE' pathogens to emphasize that they currently cause the majority of hospital acquired infections and effectively 'escape' the effects of antibacterial drugs. Thus, alternative, safer and more efficient antimicrobial strategies are urgently needed, especially against 'ESKAPE' superbugs. Antimicrobial photodynamic inactivation is a therapeutic option used in the treatment of infectious diseases. It is based on a combination of a photosensitizer, light and oxygen to remove highly metabolically active cells.
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