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Sarveswari HB, Kalimuthu S, Shanmugam K, Neelakantan P, Solomon AP. Exploration of Anti-infectives From Mangrove-Derived Micromonospora sp. RMA46 to Combat Vibrio cholerae Pathogenesis. Front Microbiol 2020; 11:1393. [PMID: 32765430 PMCID: PMC7381277 DOI: 10.3389/fmicb.2020.01393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/29/2020] [Indexed: 12/29/2022] Open
Abstract
Vibrio cholerae, the etiological agent of cholera, employs quorum sensing (QS) pathways to control the expression of virulence factors, including the production of cholera toxin and biofilm formation. Acquired antibiotic resistance in V. cholerae draws attention to the development of novel therapeutics that counteract virulence, rather than the viability of the pathogen. In this context, we explored the anti-infective potential of rare marine Actinobacteria (RMA) from a mangrove ecosystem. Here, we report the effects of Micromonospora sp. RMA46 against V. cholerae in vitro. The RMA46 organic extract was non-bactericidal to V. cholerae cells and non-cytotoxic to macrophage RAW264.7 cell lines. RMA46 inhibited the formation of V. cholerae biofilms and downregulated the QS global switches LuxO and HapR, as well as other virulence genes including ct, tcp, and hapA. In silico molecular docking simulation of RMA46 ethyl acetate extract with LuxO and HapR revealed that 2-methoxy-4-vinylphenol and hexahydro-3-(phenylmethyl)-pyrrolo[1,2-a]pyrazine-1,4-dione could interact with the active sites of LuxO and HapR and potentially inhibit them. This study highlights Micromonospora sp. RMA46 as a potential source of anti-infectives against V. cholerae.
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Affiliation(s)
- Hema Bhagavathi Sarveswari
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Shanthini Kalimuthu
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Karthi Shanmugam
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | | | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
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Deepthi KG, Prabagaran SR. Ocular bacterial infections: Pathogenesis and diagnosis. Microb Pathog 2020; 145:104206. [PMID: 32330515 DOI: 10.1016/j.micpath.2020.104206] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 12/19/2022]
Abstract
The human eye is a rigid asymmetric structure with unique defence system. Despite considerable resident microbiota, eye is exposed to external environment where a range of microorganisms also inhabits. Opportunistically, some of these microorganisms could associate with eye pathogen that could contact incidentally, leading to destructive visual consequences. Among such microbiota, bacteria form the major proportion concerning ocular complications worldwide. The succession of genome based approach through 16S rRNA gene based identification tremendously augmented the knowledge on diversity of ocular surface bacteria. Such evidence suggests that while few bacteria contribute towards normal ocular functions, considerable number of bacteria play active role in pathophysiology of ocular diseases. Thus, understanding the complexity of ocular microflora not only throw light on their critical role towards normal function of the eye, but also enlighten on certain visual exigencies. Under these circumstances, development of a rapid, reliable and cost effective method is essential that eventually evolve as a routine diagnostic protocol. Such precise prognostic modalities facilitate ophthalmologists to formulate pioneering therapeutics towards challenging ocular diseases.
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Sandhu HS, Hajrasouliha A, Kaplan HJ, Wang W. Diagnostic Utility of Quantitative Polymerase Chain Reaction versus Culture in Endophthalmitis and Uveitis. Ocul Immunol Inflamm 2018; 27:578-582. [DOI: 10.1080/09273948.2018.1431291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Harpal Singh Sandhu
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, USA
| | - Amir Hajrasouliha
- Division of Ophthalmology, Cook County Health and Hospitals System, Chicago, Illinois, USA
| | - Henry J. Kaplan
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, USA
| | - Wei Wang
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, USA
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Sjoholm-Gomez de Liano C, Soberon-Ventura VF, Salcedo-Villanueva G, Santos-Palacios A, Guerrero-Naranjo JL, Fromow-Guerra J, García-Aguirre G, Morales-Canton V, Velez-Montoya R. Sensitivity, specificity and predictive values of anterior chamber tap in cases of bacterial endophthalmitis. EYE AND VISION 2017; 4:18. [PMID: 28706959 PMCID: PMC5506679 DOI: 10.1186/s40662-017-0083-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/28/2017] [Indexed: 11/29/2022]
Abstract
Background To assess the sensitivity, specificity, positive predictive value and negative predictive value of anterior chamber tap for the diagnosis of bacterial endophthalmitis on a population with high prevalence. Methods Retrospective, single centre, case series study. We reviewed all medical records with clinical diagnosis of bacterial endophthalmitis in our hospital from January 1st, 2000 to December 31st 2014. From each record, we documented general demographic data, best corrected visual acuity and vitreous and aqueous tap microbiological results. All cases were further divided according to the endophthalmitis aetiology to perform individual calculations of sensitivity, specificity, positive predictive value, negative predictive value, accuracy and prevalence. We used the results of the vitreous tap as the gold standard for diagnosis of bacterial endophthalmitis. We excluded those records in which the aqueous and vitreous samples were not taken simultaneously or had an incomplete microbiological report. Significance were assessed with chi squared statistics, with an alpha value of 0.05 for statistical significance. Results A total of 190 cases fulfilled the inclusion/exclusion criteria. Positive culture rate from vitreous samples was 64.74%. Positive culture rate from aqueous sample was 32.11%. Bacteria isolated from aqueous samples matched those isolated from vitreous samples 78.68% of the time. The overall sensitivity was 38.21%, specificity: 75.51%, positive predictive value: 79.66%, negative predictive value: 32.74% (p = 0.08). Subgroup analysis showed that anterior chamber taps in cases of post-surgical endophthalmitis had a moderate to low sensitivity (37.73%), high specificity (93%) and high positive predictive value (95%) (p < 0.04). Conclusion The sensitivity and specificity of anterior chamber tap are low and should not be used for critical therapeutic decisions in patients with suspected bacterial endophthalmitis. In cases of post-surgical endophthalmitis, the result of an anterior chamber tap could be used for therapeutic guidance, but only in conjunction with clinical presentation and in the absence of a better method for diagnosis.
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Affiliation(s)
- Carl Sjoholm-Gomez de Liano
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico
| | - Vidal F Soberon-Ventura
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico
| | - Guillermo Salcedo-Villanueva
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico
| | | | - Jose Luis Guerrero-Naranjo
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico.,Ophthalmology Department, Macula Retina Consultants, Mexico City, Mexico
| | - Jans Fromow-Guerra
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico.,Ophthalmology Department, Macula Retina Consultants, Mexico City, Mexico
| | - Gerardo García-Aguirre
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico.,Ophthalmology Department, Macula Retina Consultants, Mexico City, Mexico
| | - Virgilio Morales-Canton
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico
| | - Raul Velez-Montoya
- Retina Department, Asociación para Evitar la Ceguera en Mexico, Hospital "Dr. Luis Sanchez Bulnes" IAP, Mexico City, Mexico.,Ophthalmology Department, Macula Retina Consultants, Mexico City, Mexico
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Buza TM, Jack SW, Kirunda H, Khaitsa ML, Lawrence ML, Pruett S, Peterson DG. ERAIZDA: a model for holistic annotation of animal infectious and zoonotic diseases. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2015; 2015:bav110. [PMID: 26581408 PMCID: PMC4651161 DOI: 10.1093/database/bav110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/21/2015] [Indexed: 12/28/2022]
Abstract
There is an urgent need for a unified resource that integrates trans-disciplinary annotations of emerging and reemerging animal infectious and zoonotic diseases. Such data integration will provide wonderful opportunity for epidemiologists, researchers and health policy makers to make data-driven decisions designed to improve animal health. Integrating emerging and reemerging animal infectious and zoonotic disease data from a large variety of sources into a unified open-access resource provides more plausible arguments to achieve better understanding of infectious and zoonotic diseases. We have developed a model for interlinking annotations of these diseases. These diseases are of particular interest because of the threats they pose to animal health, human health and global health security. We demonstrated the application of this model using brucellosis, an infectious and zoonotic disease. Preliminary annotations were deposited into VetBioBase database (http://vetbiobase.igbb.msstate.edu). This database is associated with user-friendly tools to facilitate searching, retrieving and downloading of disease-related information. Database URL: http://vetbiobase.igbb.msstate.edu.
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Affiliation(s)
- Teresia M Buza
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 USA, Institute for Genomics, Biocomputing & Biotechnology (IGBB), Mississippi State University, Mississippi State, MS 39762 USA,
| | - Sherman W Jack
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 USA and
| | - Halid Kirunda
- National Livestock Resources Research Institute (NaLIRRI), Tororo, Uganda
| | - Margaret L Khaitsa
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 USA and
| | - Mark L Lawrence
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 USA
| | - Stephen Pruett
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762 USA
| | - Daniel G Peterson
- Institute for Genomics, Biocomputing & Biotechnology (IGBB), Mississippi State University, Mississippi State, MS 39762 USA
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Kell D, Potgieter M, Pretorius E. Individuality, phenotypic differentiation, dormancy and 'persistence' in culturable bacterial systems: commonalities shared by environmental, laboratory, and clinical microbiology. F1000Res 2015; 4:179. [PMID: 26629334 PMCID: PMC4642849 DOI: 10.12688/f1000research.6709.2] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/04/2015] [Indexed: 01/28/2023] Open
Abstract
For bacteria, replication mainly involves growth by binary fission. However, in a very great many natural environments there are examples of phenotypically dormant, non-growing cells that do not replicate immediately and that are phenotypically 'nonculturable' on media that normally admit their growth. They thereby evade detection by conventional culture-based methods. Such dormant cells may also be observed in laboratory cultures and in clinical microbiology. They are usually more tolerant to stresses such as antibiotics, and in clinical microbiology they are typically referred to as 'persisters'. Bacterial cultures necessarily share a great deal of relatedness, and inclusive fitness theory implies that there are conceptual evolutionary advantages in trading a variation in growth rate against its mean, equivalent to hedging one's bets. There is much evidence that bacteria exploit this strategy widely. We here bring together data that show the commonality of these phenomena across environmental, laboratory and clinical microbiology. Considerable evidence, using methods similar to those common in environmental microbiology, now suggests that many supposedly non-communicable, chronic and inflammatory diseases are exacerbated (if not indeed largely caused) by the presence of dormant or persistent bacteria (the ability of whose components to cause inflammation is well known). This dormancy (and resuscitation therefrom) often reflects the extent of the availability of free iron. Together, these phenomena can provide a ready explanation for the continuing inflammation common to such chronic diseases and its correlation with iron dysregulation. This implies that measures designed to assess and to inhibit or remove such organisms (or their access to iron) might be of much therapeutic benefit.
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Affiliation(s)
- Douglas Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, Manchester, Lancashire, M1 7DN, UK
| | - Marnie Potgieter
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, 0007, South Africa
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, 0007, South Africa
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Kell D, Potgieter M, Pretorius E. Individuality, phenotypic differentiation, dormancy and 'persistence' in culturable bacterial systems: commonalities shared by environmental, laboratory, and clinical microbiology. F1000Res 2015; 4:179. [PMID: 26629334 DOI: 10.12688/f1000research.6709.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/29/2015] [Indexed: 01/28/2023] Open
Abstract
For bacteria, replication mainly involves growth by binary fission. However, in a very great many natural environments there are examples of phenotypically dormant, non-growing cells that do not replicate immediately and that are phenotypically 'nonculturable' on media that normally admit their growth. They thereby evade detection by conventional culture-based methods. Such dormant cells may also be observed in laboratory cultures and in clinical microbiology. They are usually more tolerant to stresses such as antibiotics, and in clinical microbiology they are typically referred to as 'persisters'. Bacterial cultures necessarily share a great deal of relatedness, and inclusive fitness theory implies that there are conceptual evolutionary advantages in trading a variation in growth rate against its mean, equivalent to hedging one's bets. There is much evidence that bacteria exploit this strategy widely. We here bring together data that show the commonality of these phenomena across environmental, laboratory and clinical microbiology. Considerable evidence, using methods similar to those common in environmental microbiology, now suggests that many supposedly non-communicable, chronic and inflammatory diseases are exacerbated (if not indeed largely caused) by the presence of dormant or persistent bacteria (the ability of whose components to cause inflammation is well known). This dormancy (and resuscitation therefrom) often reflects the extent of the availability of free iron. Together, these phenomena can provide a ready explanation for the continuing inflammation common to such chronic diseases and its correlation with iron dysregulation. This implies that measures designed to assess and to inhibit or remove such organisms (or their access to iron) might be of much therapeutic benefit.
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Affiliation(s)
- Douglas Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, Manchester, Lancashire, M1 7DN, UK
| | - Marnie Potgieter
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, 0007, South Africa
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, 0007, South Africa
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Gokhale VV, Therese KL, Bagyalakshmi R, Biswas J. Detection of Escherichia fergusonii by PCR-based DNA sequencing in a case of delayed-onset chronic endophthalmitis after cataract surgery. J Cataract Refract Surg 2014; 40:327-30. [PMID: 24461505 DOI: 10.1016/j.jcrs.2013.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 07/23/2013] [Indexed: 10/25/2022]
Abstract
UNLABELLED We report a case of chronic low-grade endophthalmitis after cataract surgery presenting with recurrent episodes of severe anterior chamber reactions and hypopyon uveitis caused by Escherichia fergusonii, which was isolated from vitreous aspirate by polymerase chain reaction-based DNA sequencing. Polymerase chain reaction has emerged as an essential, powerful, and rapid laboratory diagnostic technique and a useful adjunct to the conventional gold standard. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Varada Vinay Gokhale
- From the Uvea Department (Gokhale, Biswas), Medical Research Foundation, and L & T Microbiology Research Centre (Therese, Bagyalakshmi), Vision Research Foundation, Chennai, India.
| | - K Lily Therese
- From the Uvea Department (Gokhale, Biswas), Medical Research Foundation, and L & T Microbiology Research Centre (Therese, Bagyalakshmi), Vision Research Foundation, Chennai, India
| | - R Bagyalakshmi
- From the Uvea Department (Gokhale, Biswas), Medical Research Foundation, and L & T Microbiology Research Centre (Therese, Bagyalakshmi), Vision Research Foundation, Chennai, India
| | - Jyotirmay Biswas
- From the Uvea Department (Gokhale, Biswas), Medical Research Foundation, and L & T Microbiology Research Centre (Therese, Bagyalakshmi), Vision Research Foundation, Chennai, India
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Identification of polybacterial communities in patients with postoperative, posttraumatic, and endogenous endophthalmitis through 16S rRNA gene libraries. J Clin Microbiol 2014; 52:1459-66. [PMID: 24574297 DOI: 10.1128/jcm.02093-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Endophthalmitis is a potential vision-threatening complication following surgical procedures (postoperative endophthalmitis [POE]), trauma (posttraumatic endophthalmitis [PTE]), and bacteremic seeding of the eye from a distant infection site (endogenous endophthalmitis [EE]). Several studies have revealed the polybacterial characteristics of endophthalmitis, which make the administration of antibiotics to treat the disease challenging. However, until now, the polybacterial communities of POE, PTE, and EE have not been precisely studied. Hence, the present study was designed to identify the bacterial community of endophthalmitis through 16S rRNA gene libraries. Of the 40 intraocular samples tested, 30 libraries were constructed with bacterial nested-PCR-positive samples. The obtained recombinant clones were screened through amplified rRNA gene restriction analysis (ARDRA) to identify unique clones. The multiple types of ARDRA patterns (P=0.345) and diverse bacterial sequences (P=0.277) within the libraries revealed the polybacterial nature of infection in POE, PTE, and EE. Moreover, to the best of our knowledge, this is the first report on polybacterial infection in EE. Gram-positive bacteria, including Bacillus spp. (n=19), Streptococcus spp. (n=18), Staphylococcus spp. (n=6), Exiguobacterium spp. (n=3), Gemella spp. (n=2), Enterococcus spp. (n=2), a Lysinibacillus sp. (n=1), a Clostridium sp. (n=1), and a Nocardia sp. (n=1), and Gram-negative bacteria, including Serratia spp. (n=18), Pseudomonas spp. (n=10), Enterobacter spp. (n=8), Acinetobacter spp. (n=3), Pantoea spp. (n=3), a Haemophilus sp. (n=1), and a Massilia sp. (n=1), were identified. Interestingly, among them, 10 bacterial species were not previously reported to be associated with endophthalmitis or other ocular infections. Besides, the presence of 4 unidentifiable clones suggests the possibility of novel organisms that might cause eye infections. Therefore, it is recommended that, in addition to the polybacterial nature of POE, PTE, and EE infections, the spectrum of the pathogenic bacterial community identified in this work should be considered while administering antibiotic therapy in suspected endophthalmitis cases.
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Kirkup BC, Mahlen S, Kallstrom G. Future-Generation Sequencing and Clinical Microbiology. Clin Lab Med 2013; 33:685-704. [DOI: 10.1016/j.cll.2013.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Orr Gandy KA, Obeid LM. Targeting the sphingosine kinase/sphingosine 1-phosphate pathway in disease: review of sphingosine kinase inhibitors. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:157-66. [PMID: 22801037 DOI: 10.1016/j.bbalip.2012.07.002] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 07/05/2012] [Accepted: 07/06/2012] [Indexed: 12/01/2022]
Abstract
Sphingosine 1-phosphate (S1P) is an important bioactive sphingolipid metabolite that has been implicated in numerous physiological and cellular processes. Not only does S1P play a structural role in cells by defining the components of the plasma membrane, but in the last 20 years it has been implicated in various significant cell signaling pathways and physiological processes: for example, cell migration, survival and proliferation, cellular architecture, cell-cell contacts and adhesions, vascular development, atherosclerosis, acute pulmonary injury and respiratory distress, inflammation and immunity, and tumorogenesis and metastasis [1,2]. Given the wide variety of cellular and physiological processes in which S1P is involved, it is immediately obvious why the mechanisms governing S1P synthesis and degradation, and the manner in which these processes are regulated, are necessary to understand. In gaining more knowledge about regulation of the sphingosine kinase (SK)/S1P pathway, many potential therapeutic targets may be revealed. This review explores the roles of the SK/S1P pathway in disease, summarizes available SK enzyme inhibitors and examines their potential as therapeutic agents. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.
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Affiliation(s)
- K Alexa Orr Gandy
- The Department of Molecular and Cellular Biology, The Medical University of South Carolina, Charleston, SC 29425, USA
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Aarthi P, Bagyalakshmi R, Therese KL, Malathi J, Mahalakshmi B, Madhavan HNR. Optimization and application of a reverse transcriptase polymerase chain reaction to determine the bacterial viability in infectious endophthalmitis. Curr Eye Res 2012; 37:1114-20. [PMID: 22757687 DOI: 10.3109/02713683.2012.704476] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To develop RNA based assay - reverse transcriptase polymerase chain reaction (RT-PCR) to detect viable bacteria in intraocular specimens obtained from patients with infectious endophthalmitis. MATERIALS AND METHODS Thirty-five intraocular specimens (19 vitreous fluid and 16 aqueous humor) collected from patients with typical infectious endophthalmitis were subjected to conventional and molecular microbiological investigations. Culture negative, eubacterial genome PCR positive intraocular specimens were subjected to denaturing high performance liquid chromatography (dHPLC) for separation of mixed genomes and subsequently identified by PCR based DNA sequencing. In parallel, RT-PCR was performed to detect the presence of viable bacteria in intraocular specimens. RESULTS Among 35 intraocular specimens, single bacterial genome was detected in 9 (25.7%) and two or more genomes in 26 (74.28%) intraocular specimens. Eubacterial genome was detected by RT-PCR in 29 (82.85%) specimens. PCR based dHPLC followed by PCR based DNA sequencing revealed the presence of 65 bacterial genomes in 35 intraocular specimens. Five novel genera namely Terrabacter species, Facklamia species, Xylella fastidiosa, Duganella species and Synechococcus species were detected. CONCLUSION RT-PCR serves as a rapid and reliable tool to detect viable bacteria causing endophthalmitis.
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Affiliation(s)
- Pasupathi Aarthi
- Larsen and Toubro Microbiology Research Centre, Kamal Nayan Bajaj Institute for Research in Vision and Ophthalmology, Vision Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
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Joseph CR, Lalitha P, Sivaraman KR, Ramasamy K, Behera UC. Real-time polymerase chain reaction in the diagnosis of acute postoperative endophthalmitis. Am J Ophthalmol 2012; 153:1031-7.e2. [PMID: 22381364 DOI: 10.1016/j.ajo.2011.12.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 12/17/2011] [Accepted: 12/19/2011] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the efficacy of quantitative real-time polymerase chain reaction (qPCR) in the diagnosis of postoperative bacterial endophthalmitis among patients who underwent cataract surgery at a tertiary care center. DESIGN Prospective experimental study. METHODS This was a single-center study of 64 eyes of 64 patients presenting with clinical signs and symptoms of endophthalmitis within 1 year of cataract surgery. Patients with glaucoma filtering or cornea surgery in the past year, postoperative trauma, fungal endophthalmitis, or preoperative inflammatory conditions were excluded. Vitreous samples were obtained during vitreous tap or vitrectomy and sent for both culture and qPCR with sequencing. Vitreous samples obtained from 50 patients undergoing vitrectomy for noninflammatory indications served as controls. The main outcome measures were the sensitivity of qPCR compared to culture and concordance of results of pathogen identification with sequencing vs phenotypic speciation. RESULTS qPCR detected 16s bacterial DNA in 37 patients (66%), compared to 19 (34%) with traditional culture. Only 1 patient had a positive result by culture (Nocardia species) but negative result by qPCR. For the 18 samples positive by both qPCR and culture, there was a 100% concordance in pathogen identification between sequencing and phenotypic speciation. CONCLUSION In cases of suspected bacterial endophthalmitis, qPCR offers an improved diagnostic yield and may be a useful adjunct to traditional culture. Further large-scale clinical studies are needed to elucidate the full clinical utility of qPCR.
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Affiliation(s)
- Cornelia Reena Joseph
- Department of Microbiology, Dr G. Venkasamy Eye Research Institute Aravind Medical Research Foundation, Madurai, Tamil Nadu, India
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