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Romano V, Ferrara M, Gatti F, Airaldi M, Borroni D, Aragona E, Rocha-de-Lossada C, Gabrielli F, Papa FT, Romano MR, Calza S, Semeraro F. Topical Antiseptics in Minimizing Ocular Surface Bacterial Load Before Ophthalmic Surgery: A Randomized Controlled Trial. Am J Ophthalmol 2024; 261:165-175. [PMID: 38211781 DOI: 10.1016/j.ajo.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/28/2023] [Accepted: 01/05/2024] [Indexed: 01/13/2024]
Abstract
PURPOSE To investigate the reduction of the ocular surface bacterial load induced by 2 commercially available ophthalmic antiseptic formulations, povidone-iodine (PVI) 0.6% and chlorhexidine (CLX) 0.02%, before ocular surgery. DESIGN Randomized controlled trial. METHODS Seventy adult patients undergoing intraocular surgery (phacoemulsification) were randomized to receive in the index eye PVI (group A) 4 times a day for 3 days or CLX (group B) 4 times a day for 3 days before surgery. The untreated eye was used as control. A conjunctival swab was taken in both eyes before (T0) and after (T1) therapy. Microbial DNA was quantified with real-time polymerase chain reaction (PCR) analysis. The Mick algorithm was used to compare the abundance of each genus/genera against the distribution of abundances from the reference. At T1, patients filled a questionnaire to evaluate therapy-induced symptoms. Primary outcome was the reduction of bacterial DNA at T1 (microbial load), vs control arm, expressed as mean number of real-time PCR cycle times (CTs). Secondary outcomes were taxonomic composition, differential abundance, and therapy-induced ocular symptoms. RESULTS The T0-T1 difference in CT was significant in group B, but not in group A (mean [95% CI], 0.99 [0.33] vs 0.26 [0.15], P < .001, and 0.65 [0.3] vs 0.45 [0.41], P = .09, respectively). The taxonomic composition, alpha, and beta diversity remained consistent at all time points in both groups. The rate of patients reporting therapy-induced ocular symptoms and the mean discomfort grade were greater in group A than in group B (97% vs 26% and 4.97±2.48 vs 0.66±1.53, respectively). CONCLUSIONS Compared with PVI 0.6%, CLX 0.02% induced a greater reduction of ocular surface bacterial load, with no significant alterations of the taxonomic composition. Moreover, CLX was better tolerated than PVI.
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Affiliation(s)
- Vito Romano
- From the Eye Unit, ASST Spedali Civili di Brescia (V.R., F.S.), Brescia, Italy; Eye Unit, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia (V.R., Fr.G., F.S.), Brescia, Italy
| | | | - Francesca Gatti
- Eye Unit, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia (V.R., Fr.G., F.S.), Brescia, Italy
| | - Matteo Airaldi
- Department of Molecular and Translational Medicine, Università degli Studi di Brescia (M.A.), Brescia, Italy; St. Paul's Eye Unit, Royal Liverpool University Hospital (M.A.), Liverpool, United Kingdom
| | - Davide Borroni
- Eyemetagenomics Ltd, Covent Garden (D.B., C.R.-d.-l.), London, United Kingdom
| | - Emanuela Aragona
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute (E.A.), Milan, Italy
| | - Carlos Rocha-de-Lossada
- Eyemetagenomics Ltd, Covent Garden (D.B., C.R.-d.-l.), London, United Kingdom; Ophthalmology Department, QVision, Vithas Almería (C.R.-d.-l.), Almeria, Spain; Ophthalmology Department, Hospital Regional Universitario Málaga (C.R.-d.-l.), Malaga, Spain
| | - Federico Gabrielli
- Biolab SRL, Laboratorio di Genetica e Genomica Molecolare (Fe.G., F.T.P.), Ascoli Piceno, Italy
| | - Filomena Tiziana Papa
- Biolab SRL, Laboratorio di Genetica e Genomica Molecolare (Fe.G., F.T.P.), Ascoli Piceno, Italy
| | - Mario R Romano
- Department of Biomedical Sciences, Humanitas University (M.R.R.), Milan, Italy; Department of Ophthalmology, Humanitas Gavazzeni-Castelli (M.R.R.), Bergamo, Italy
| | - Stefano Calza
- Unit of Biostatistics and Bioinformatics, Department of Molecular and Translational Medicine, University of Brescia (S.C.), Brescia, Italy
| | - Francesco Semeraro
- From the Eye Unit, ASST Spedali Civili di Brescia (V.R., F.S.), Brescia, Italy; Eye Unit, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia (V.R., Fr.G., F.S.), Brescia, Italy
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Chen Z, Xiao Y, Jia Y, Lin Q, Qian Y, Cui L, Xiang Z, Li M, Yang C, Zou H. Metagenomic analysis of microbiological changes on the ocular surface of diabetic children and adolescents with a dry eye. BMC Microbiol 2023; 23:286. [PMID: 37803284 PMCID: PMC10557306 DOI: 10.1186/s12866-023-03013-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 09/11/2023] [Indexed: 10/08/2023] Open
Abstract
BACKGROUND Microbiome changes on the ocular surface may cause dry eyes. A metagenome assay was used to compare the microbiome composition and function of the ocular surface between diabetic children and adolescents with dry eye, diabetic children and adolescents without dry eye, and normal children. MATERIALS AND METHODS Twenty children and adolescents aged 8 to 16 with diabetes were selected from the Shanghai Children and Adolescent Diabetes Eye Study. Ten healthy children and adolescents belonging to the same age group were selected from the outpatient clinic during the same period. The participants were classified into the dry eye group (DM-DE group, n = 10), the non-dry eye group (DM-NDE group, n = 10) and the normal group (NDM group, n = 10). A conjunctival sac swab was collected for metagenomic sequencing, and the relationship between the microbiome composition and functional gene differences on the ocular surface with dry eye was studied. RESULTS The classification composition and metabolic function of the microorganisms on the ocular surface of children in the 3 groups were analyzed. It was found that children's ocular microbiota was composed of bacteria, viruses and fungi. There were significant differences in α diversity and β diversity of microbial composition of ocular surface between DM-DE group and NDM group(P<0.05). There were significant differences in α and β diversity of metabolic pathways between the two groups(P<0.05). The functional pathways of ocular surface microorganisms in diabetic children with dry eyes were mainly derived from human disease, antibiotic resistance genes, carbohydrate, coenzyme and lipid transport and metabolism-related functional genes; In normal children, the functional pathways were mainly derived from replication, recombination, repair, signal transduction and defense-related functional genes. CONCLUSION The DM-DE group have unique microbial composition and functional metabolic pathways. The dominant species and unique metabolic pathways of the ocular surface in the DM-DE group may be involved in the pathogenesis of dry eye in diabetic children.
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Affiliation(s)
- Zhangling Chen
- Department of Ophthalmology, Shanghai General Hospital, Nanjing Medical University, Shanghai, China
- Department of Ophthalmology, Shanghai Songjiang District Central Hospital, Shanghai, China
| | - Ying Xiao
- Department of Ophthalmology, Children's Hospital of Fudan University, Shanghai, China
| | - Yan Jia
- Department of Ophthalmology, Children's Hospital of Fudan University, Shanghai, China
| | - Qiurong Lin
- Shanghai Eye Diseases Prevention & Treatment Center/Shanghai Eye Hospital, Shanghai, China
| | - Yu Qian
- Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lipu Cui
- Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhaoyu Xiang
- Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Mingfang Li
- Department of Ophthalmology, Shanghai Songjiang District Central Hospital, Shanghai, China
| | - Chenhao Yang
- Department of Ophthalmology, Children's Hospital of Fudan University, Shanghai, China.
| | - Haidong Zou
- Department of Ophthalmology, Shanghai General Hospital, Nanjing Medical University, Shanghai, China.
- Shanghai Eye Diseases Prevention & Treatment Center/Shanghai Eye Hospital, Shanghai, China.
- Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
- Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.
- National Clinical Research Center for Eye Diseases, Shanghai, China.
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China.
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Ozkan J, Majzoub ME, Coroneo M, Thomas T, Willcox M. Ocular microbiome changes in dry eye disease and meibomian gland dysfunction. Exp Eye Res 2023; 235:109615. [PMID: 37586456 DOI: 10.1016/j.exer.2023.109615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 07/17/2023] [Accepted: 08/11/2023] [Indexed: 08/18/2023]
Abstract
The most common and chronic ocular problem of aging is dry eye disease (DED) and the associated condition of meibomian gland dysfunction (MGD). The resident ocular surface bacteria may have a role in maintaining homeostasis and perturbation may contribute to disease development. The aim of this study was to compare the microbiomes of the conjunctiva and eyelid margin in humans with mild and moderate DED and controls using 16 S rRNA gene sequencing. The conjunctiva and lid margin of three cohorts (N = 60; MGD, MGD with lacrimal dysfunction [MGD + LD] and controls) were swabbed bilaterally three times over three months. Microbial communities were analysed by extracting DNA and sequencing the V3-V4 region of the 16 S ribosomal RNA gene using the Illumina MiSeq platform. Sequences were quality filtered, clustered into amplicon sequence variants (ASVs) using UNOISE algorithm and taxonomically classified using a Bayesian Last Common Ancestor (BCLA) algorithm against the GTDB 2207 database. The overall microbial communities of the MGD, MGD + LD and control groups were significantly different from each other (P = 0.001). The MGD and MGD + LD dry eye groups showed greater variability between individuals compared to the control (PERMDISP, P < 0.01). There was decreased richness and diversity in females compared to males for the conjunctiva (P < 0.04) and eyelid margin (P < 0.018). The conjunctiva in the MGD + LD group had more abundant Pseudomonas azotoformans, P. oleovorans and Caballeronia zhejiangensis compared to MGD and control (P < 0.05), while the MGD group had more abundant Corynebacterium macginleyi and C. kroppenstedtii compared to control (P < 0.05). The lid margin in MGD was more abundant in C. macginleyi, C. accolens, and C. simulans compared to the MGD + LD and control (P < 0.05). There were differences in the overall microbial community composition and certain taxa, including increased levels of lipophilic bacteria, on the conjunctiva and eyelid margin in mild to moderate DED/MGD compared to controls. DED/MGD was also associated with a reduced bacterial richness and diversity in females.
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Affiliation(s)
- Jerome Ozkan
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia; Centre for Marine Science and Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.
| | - Marwan E Majzoub
- Host-Microbiome Interactions Group, School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, Australia
| | - Minas Coroneo
- Department of Ophthalmology, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Torsten Thomas
- Centre for Marine Science and Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Herzog EL, Kreuzer M, Zinkernagel MS, Zysset-Burri DC. Challenges and insights in the exploration of the low abundance human ocular surface microbiome. Front Cell Infect Microbiol 2023; 13:1232147. [PMID: 37727808 PMCID: PMC10505673 DOI: 10.3389/fcimb.2023.1232147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/18/2023] [Indexed: 09/21/2023] Open
Abstract
Purpose The low microbial abundance on the ocular surface results in challenges in the characterization of its microbiome. The purpose of this study was to reveal factors introducing bias in the pipeline from sample collection to data analysis of low-abundant microbiomes. Methods Lower conjunctiva and lower lid swabs were collected from six participants using either standard cotton or flocked nylon swabs. Microbial DNA was isolated with two different kits (with or without prior host DNA depletion and mechanical lysis), followed by whole-metagenome shotgun sequencing with a high sequencing depth set at 60 million reads per sample. The relative microbial compositions were generated using the two different tools MetaPhlan3 and Kraken2. Results The total amount of extracted DNA was increased by using nylon flocked swabs on the lower conjunctiva. In total, 269 microbial species were detected. The most abundant bacterial phyla were Actinobacteria, Firmicutes and Proteobacteria. Depending on the DNA extraction kit and tool used for profiling, the microbial composition and the relative abundance of viruses varied. Conclusion The microbial composition on the ocular surface is not dependent on the swab type, but on the DNA extraction method and profiling tool. These factors have to be considered in further studies about the ocular surface microbiome and other sparsely colonized microbiomes in order to improve data reproducibility. Understanding challenges and biases in the characterization of the ocular surface microbiome may set the basis for microbiome-altering interventions for treatment of ocular surface associated diseases.
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Affiliation(s)
- Elio L. Herzog
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Marco Kreuzer
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| | - Martin S. Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Denise C. Zysset-Burri
- Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
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Rigas Y, Treat BR, Shane J, Shanks RMQ, St. Leger AJ. Genetic Manipulation of Corynebacterium mastitidis to Better Understand the Ocular Microbiome. Invest Ophthalmol Vis Sci 2023; 64:19. [PMID: 36799874 PMCID: PMC9942783 DOI: 10.1167/iovs.64.2.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 01/24/2023] [Indexed: 02/18/2023] Open
Abstract
Purpose Corynebacterium spp. are Gram-positive bacteria commonly associated with the ocular surface. Corynebacterium mastitidis was isolated from mouse eyes and was demonstrated to induce a beneficial immune response that can protect the eye from pathogenic infection. Because eye-relevant Corynebacterium spp. are not well described, we generated a C. mast transposon (Tn) mutant library to gain a better understanding of the nature of eye-colonizing bacteria. Methods Tn mutagenesis was performed with a custom Tn5-based transposon that incorporated a promoterless gene for the fluorescent protein mCherry. We screened our library using flow cytometry and enzymatic assays to identify useful mutants that demonstrate the utility of our approach. Results Fluorescence-activated cell sorting (FACS) of mCherry+ bacteria allowed us to identify a highly fluorescent mutant that was detectable on the murine ocular surface using microscopy. We also identified a functional knockout that was unable to hydrolyze urea, UreaseKO. Although uric acid is an antimicrobial factor produced in tears, UreaseKO bacterium maintained an ability to colonize the eye, suggesting that urea hydrolysis is not required for colonization. In vitro and in vivo, both mutants maintained the potential to stimulate protective immunity as compared to wild-type C. mast. Conclusions In sum, we describe a method to genetically modify an eye-colonizing microbe, C. mast. Furthermore, the procedures outlined here will allow for the continued development of genetic tools for modifying ocular Corynebacterium spp., which will lead to a more complete understanding of the interactions between the microbiome and host immunity at the ocular surface.
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Affiliation(s)
- Yannis Rigas
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh Pennsylvania, United States
| | - Benjamin R. Treat
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh Pennsylvania, United States
| | - Jackie Shane
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh Pennsylvania, United States
| | - Robert M. Q. Shanks
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh Pennsylvania, United States
| | - Anthony J. St. Leger
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh Pennsylvania, United States
- Department of Immunology, University of Pittsburgh, Pittsburgh Pennsylvania, United States
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Chen Z, Xiang Z, Cui L, Qin X, Chen S, Jin H, Zou H. Significantly different results in the ocular surface microbiome detected by tear paper and conjunctival swab. BMC Microbiol 2023; 23:31. [PMID: 36707800 PMCID: PMC9883858 DOI: 10.1186/s12866-023-02775-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 01/16/2023] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Great variation has been observed in the composition of the normal microbiota of the ocular surface, and therefore, in addition to differences in detection techniques, the method of collecting ocular surface specimens has a significant impact on the test results.The goal of this study is to ascertain whether the eye surface microbial communities detected by two different sampling methods are consistent and hence explore the feasibility of using tear test paper instead of conjunctival swabs to collect eye surface samples for microbial investigation. MATERIALS AND METHODS From July 15, 2021, to July 30, 2021, nonirritating tear test strips and conjunctival swabs of both eyes were used in 158 elderly people (> 60 years old) (79 diabetic and 79 nondiabetic adults) in Xinjing Community for high-throughput sequencing of the V3-V4 region of the 16S rRNA gene. The composition of the microbial communities in tear test paper and conjunctival swab samples was analyzed. RESULTS There was no statistically significant difference in Alpha diversity of ocular surface microorganisms represented by tear strip and conjunctival swab in diabetic group (P > 0.05), but there was statistically significant difference in Alpha diversity of ocular surface microorganisms detected by tear strip and conjunctival swab in nondiabetic group (P < 0.05). There were statistically significant differences in Beta diversity of ocular surface microorganisms detected by two sampling methods between diabetic group and nondiabetic group (P < 0.05). There were statistically significant differences in ocular surface microorganisms detected by tear strip method between diabetic group and nondiabetic group (P < 0.05), but there was no statistically significant difference in conjunctival swab method (P > 0.05). CONCLUSIONS Tear test paper and conjunctival swabs detect different compositions of microbes through two different techniques of eye surface microbe sampling. Tear test paper cannot completely replace conjunctival swab specimens for the study of microbes related to eye surface diseases.
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Affiliation(s)
- Zhangling Chen
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Preparatory Stage), Shanghai, China ,grid.412478.c0000 0004 1760 4628Department of Ophthalmology, Shanghai General Hospital, Nanjing Medical University, Hongkou District, No. 100, Haining Road, Shanghai, 200080 China
| | - Zhaoyu Xiang
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lipu Cui
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xinran Qin
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shuli Chen
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Huiyi Jin
- grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Haidong Zou
- grid.412478.c0000 0004 1760 4628Department of Ophthalmology, Shanghai General Hospital, Nanjing Medical University, Hongkou District, No. 100, Haining Road, Shanghai, 200080 China ,grid.16821.3c0000 0004 0368 8293Department of Ophthalmology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Key Laboratory of Fundus Diseases, Shanghai, China ,Shanghai Eye Diseases Prevention & Treatment Center/Shanghai Eye Hospital, Shanghai, China ,grid.412478.c0000 0004 1760 4628National Clinical Research Center for Eye Diseases, Shanghai, China ,grid.412478.c0000 0004 1760 4628Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
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Delbeke H, Casteels I, Joossens M. DNA extraction protocol impacts ocular surface microbiome profile. Front Microbiol 2023; 14:1128917. [PMID: 37152736 PMCID: PMC10157640 DOI: 10.3389/fmicb.2023.1128917] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/20/2023] [Indexed: 05/09/2023] Open
Abstract
Purpose The aim of this study is to provide a reference frame to allow the comparison and interpretation of currently published studies on 16S ribosomal ribonucleic acid amplicon sequencing of ocular microbiome samples using different DNA extraction protocols. Alongside, the quantitative and qualitative yield and the reproducibility of different protocols has been assessed. Methods Both eyes of 7 eligible volunteers were sampled. Five commercially available DNA extraction protocols were selected based on previous publications in the field of the ocular surface microbiome and 2 host DNA depletion protocols were added based on their reported effective host DNA depletion without significant reduction in bacterial DNA concentration. The V3-V4 region of the 16S rRNA gene was targeted using Illumina MiSeq sequencing. The DADA2 pipeline in R was used to perform the bio-informatic processing and taxonomical assignment was done using the SILVA v132 database. The Vegdist function was used to calculate Bray-Curtis distances and the Galaxy web application was used to identify potential metagenomic biomarkers via linear discriminant analysis Effect Size (LEfSe). The R package Decontam was applied to control for potential contaminants. Results Samples analysed with PowerSoil, RNeasy and NucleoSpin had the highest DNA yield. The host DNA depletion kits showed a very low microbial DNA yield; and these samples were pooled per kit before sequencing. Despite pooling, 1 of both failed to construct a library.Looking at the beta-diversity, clear microbial compositional differences - dependent on the extraction protocol used - were observed and remained present after decontamination. Eighteen genera were consistently retrieved from the ocular surface of every volunteer by all non-pooled extraction kits and a comprehensive list of differentially abundant bacteria per extraction method was generated using LefSe analysis. Conclusion High-quality papers have been published in the field of the ocular surface microbiome but consensus on the importance of the extraction protocol used are lacking. Potential contaminants and discriminative genera per extraction protocol used, were introduced and a reference frame was built to facilitate both the interpretation of currently published papers and to ease future choice - making based on the research question at hand.
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Affiliation(s)
- Heleen Delbeke
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
- Department of Neurosciences, Research Group Ophthalmology, Biomedical Sciences Group, KU Leuven, Leuven, Belgium
- *Correspondence: Heleen Delbeke,
| | - Ingele Casteels
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
- Department of Neurosciences, Research Group Ophthalmology, Biomedical Sciences Group, KU Leuven, Leuven, Belgium
| | - Marie Joossens
- Laboratory of Microbiology, Department of Biochemistry and Microbiology (WE10), Ghent University, Ghent, Belgium
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Tong L, Constancias F, Hou A, Chua SL, Drautz-Moses DI, Schuster SC, Yang L, Williams RBH, Kjelleberg S. Shotgun metagenomic sequencing analysis of ocular surface microbiome in Singapore residents with mild dry eye. Front Med (Lausanne) 2022; 9:1034131. [PMID: 36438051 PMCID: PMC9684611 DOI: 10.3389/fmed.2022.1034131] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/24/2022] [Indexed: 07/30/2023] Open
Abstract
The ocular surface microbiome has implications for ocular surface inflammation and immunology. Previous shotgun metagenomics analyses were performed in China, showing results that differed according to environment and age. Patients with Sjogren's syndrome were reported to have altered conjunctival microbiome, but such studies have not been done in milder dry eye. The aim of this study is to describe the conjunctival microbiome in people with mild dry eye in Singapore. Samples were collected from 14 participants with mild dry eye and 10 age-matched comparison participants recruited from Singapore National Eye Centre (SNEC) clinics. Shotgun metagenomic sequencing analysis was employed to evaluate the conjunctival microbiome composition. Proteobacteria formed the predominant phylum in the conjunctiva. As in a study from a coastal city in China, Achromobacter spp. was numerically most abundant. Compared to age-matched controls, the conjunctival microbial composition in mild dry eye was similar. Several microorganisms, including Streptococcus spp. increased in representation with age, and the abundance of Staphylococcus correlated with Schirmer readings. In addition, when cultured corneal epithelial cells were exposed to three strains of Achromobacter xylosoxidans, cytokines such as TNF-α and IL-6 were upregulated in the cell lysates and supernatants. Ourresults suggest that age is an important factor that affects composition of the conjunctival microbiome, and relative abundance of specific microorganism may vary according to the environment of the human host.
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Affiliation(s)
- Louis Tong
- Ocular Surface Research Group, Singapore Eye Research Institute, Singapore, Singapore
- Corneal and External Eye Disease Service, Singapore National Eye Centre, Singapore, Singapore
- Eye-Academic Clinical Programme, Office of Clinical, Academic and Faculty Affairs, Duke-NUS Medical School, Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Florentin Constancias
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Aihua Hou
- Ocular Surface Research Group, Singapore Eye Research Institute, Singapore, Singapore
- Eye-Academic Clinical Programme, Office of Clinical, Academic and Faculty Affairs, Duke-NUS Medical School, Singapore, Singapore
| | - Song Lin Chua
- Lee Kong Chian School of Medicine (LKCMedicine), Nanyang Technological University, Singapore, Singapore
| | - Daniela I. Drautz-Moses
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
| | - Stephan Christoph Schuster
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Liang Yang
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Rohan B. H. Williams
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Staffan Kjelleberg
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Centre for Marine Science and Innovation, School of Biological Earth and Environmental Sciences, University of New South Wales, Kensington, NSW, Australia
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Cavuoto KM, Zhu AY. The Role of the Ocular Surface Microbiome (OSM) in Diseases of the Anterior Segment and Ocular Surface. Curr Ophthalmol Rep 2022. [DOI: 10.1007/s40135-022-00294-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Ji X, Dong K, Pu J, Yang J, Zhang Z, Ning X, Ma Q, Kang Z, Xu J, Sun B. Comparison of the ocular surface microbiota between thyroid-associated ophthalmopathy patients and healthy subjects. Front Cell Infect Microbiol 2022; 12:914749. [PMID: 35959376 PMCID: PMC9360483 DOI: 10.3389/fcimb.2022.914749] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/04/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose Thyroid-associated ophthalmopathy (TAO) is a chronic autoimmune disease. In this study, high-throughput sequencing was used to investigate the diversity and composition of the ocular microbiota in patients with TAO. Methods Patients with TAO did not receive treatment for the disease and did not have exposed keratitis. Patients with TAO (TAO group) and healthy individuals (control group) were compared. All samples were swabbed at the conjunctival vault of the lower eyelid. The V3 to V4 region of the 16S rDNA was amplified using polymerase chain reaction and sequenced on the Illumina HiSeq 2500 Sequencing Platform. Statistical analysis was performed to analyze the differences between the groups and the correlation between ocular surface microbiota and the disease. The ocular surface microbiota of patients and healthy individuals were cultured. Results The ocular surface microbiota structure of TAO patients changed significantly. The average relative abundance of Bacillus and Brevundimonas increased significantly in the TAO group. Corynebacterium had a significantly decreased relative abundance (P<0.05). Paracoccus, Haemophilus, Lactobacillus, and Bifidobacterium were positively correlated with the severity of clinical manifestations or disease activity (P<0.05). Bacillus cereus and other opportunistic pathogens were obtained by culture from TAO patients. Conclusions This study found that the composition of ocular microbiota in patients with TAO was significantly different from that in healthy individuals. The ocular surface opportunistic pathogens, such as Bacillus, Brevundimonas, Paracoccus, and Haemophilus in TAO patients, increase the potential risk of ocular surface infection. The findings of this study provide a new avenue of research into the mechanism of ocular surface in TAO patients.
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Affiliation(s)
- Xuan Ji
- Shanxi Eye Hospital, Shanxi Province Key Laboratory of Ophthalmology, Taiyuan, China
| | - Kui Dong
- Shanxi Eye Hospital, Shanxi Province Key Laboratory of Ophthalmology, Taiyuan, China
| | - Ji Pu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018 RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Jing Yang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018 RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Zhaoxia Zhang
- Shanxi Eye Hospital, Shanxi Province Key Laboratory of Ophthalmology, Taiyuan, China
| | - Xiaoling Ning
- Shanxi Eye Hospital, Shanxi Province Key Laboratory of Ophthalmology, Taiyuan, China
| | - Qin Ma
- Shanxi Eye Hospital, Shanxi Province Key Laboratory of Ophthalmology, Taiyuan, China
| | - Zhiming Kang
- Shanxi Eye Hospital, Shanxi Province Key Laboratory of Ophthalmology, Taiyuan, China
| | - Jianguo Xu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Research Units of Discovery of Unknown Bacteria and Function (2018 RU010), Chinese Academy of Medical Sciences, Beijing, China
| | - Bin Sun
- Shanxi Eye Hospital, Shanxi Province Key Laboratory of Ophthalmology, Taiyuan, China
- *Correspondence: Bin Sun,
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11
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Datta A, Lee J, Truong T, Evans DJ, Fleiszig SMJ. Topical antibiotics reduce CD11c+ cell numbers in the healthy murine cornea and modulate their response to contact lens wear. Sci Rep 2022; 12:10655. [PMID: 35739166 PMCID: PMC9226138 DOI: 10.1038/s41598-022-14847-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 06/13/2022] [Indexed: 11/21/2022] Open
Abstract
Previously we reported contact lens-induced CD11c+ cell responses in healthy mouse corneas, a phenomenon that also occurs in humans. To test involvement of ocular-associated bacteria, the impact of topical antibiotics on corneal CD11c+ cell populations during 24 h of lens wear was examined. Corneas were treated with gentamicin and ofloxacin (0.3%) or gentamicin alone, some also treated prior to lens wear (24 h). Contralateral PBS-treated eyes served as controls. CD11c-YFP (Yellow Fluorescent Protein) mice allowed CD11c+ cell visualization. Viable bacteria, on the ocular surface or contact lens, were labeled using FISH (16S rRNA-targeted probe) or click-chemistry (alkDala). Antibiotic treatment reduced baseline CD11c+ cell numbers without lens wear and suppressed CD11c+ cell responses to lens wear if corneas were both pretreated and treated during wear. Few bacteria colonized corneas or lenses under any circumstances. Conjunctival commensals were significantly reduced by antibiotics with or without lens wear, but minimally impacted by lens wear alone. Deliberate inoculation with conjunctival commensals triggered CD11c+ cell responses irrespective of antibiotic pretreatment. These results suggest that while lens wear does not necessarily increase quantifiable numbers of conjunctival commensals, those neutralized by antibiotics play a role in lens-associated CD11c+ cell responses and maintaining baseline CD11c+ cell populations.
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Affiliation(s)
- Ananya Datta
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA
| | - Justin Lee
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA
| | - Tiffany Truong
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA
| | - David J Evans
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA.,College of Pharmacy, Touro University California, Vallejo, CA, USA
| | - Suzanne M J Fleiszig
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, 94720, USA. .,Graduate Groups in Vision Science, Microbiology, and Infectious Diseases and Immunity, University of California, Berkeley, CA, USA.
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12
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Lee J, Lim S, Shin JH, Lee Y, Seo JH. Differences in the eyelid and buccal microbiome between open-angle glaucoma and uveitic glaucoma. Acta Ophthalmol 2022; 100:e770-e778. [PMID: 34233092 DOI: 10.1111/aos.14967] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 06/17/2021] [Indexed: 12/21/2022]
Abstract
PURPOSE Microbiomes have immunoregulatory functions and may be involved in the pathophysiology of eye diseases. However, the effects of microbiomes on uveitic glaucoma (UG) and open-angle glaucoma (OAG) have not been sufficiently investigated. This study analysed differences in eyelid and buccal microbiomes between UG and OAG using metagenomic technology. METHODS Eyelid and buccal specimens were collected from 34 UG and 62 OAG patients. The taxonomic composition of the microbiome was determined via 16S rRNA gene sequencing, operational taxonomic unit analysis and diversity analysis. Differential gene expression analysis (DEG) and principal component analyses (PCoA) determined taxon differences between the microbiomes of the UG and OAG patients. Subgroup analysis according to age and baseline IOP was performed. RESULTS There was no significant difference in alpha-diversity between the microbiomes of UG and OAG patients. Further, PCoA revealed no differences in eyelid microbiome between the UG and OAG groups, but significant differences were found in buccal microbiome between the groups, especially in a subgroup of OAG patients with normal IOP. DEG analysis of the eyelid microbiome revealed various taxa differences, including the enrichment of Rhodococcus in UG samples over OAG samples. Taxa such as Lactobacillus and Proteus were significantly depleted (q-value = 9.98e-6 and q-value = 1.38 × 10-4 , respectively) in the buccal microbiome of UG patients, whereas Enterococcus was enriched (q-value = 5.26e-5 ). CONCLUSIONS This study showed that the buccal microbiome in UG differs from that in OAG; reduced Lactobacillus was observed in UG. These results suggest that apart than OAG, microbiome composition may be a factor in the pathogenesis of UG.
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Affiliation(s)
- Ji‐Woong Lee
- Department of Ophthalmology Pusan National University Hospital Busan Korea
| | - Su‐Ho Lim
- Department of Ophthalmology Daegu Veterans Health Service Medical Center Daegu Korea
| | - Jong Hoon Shin
- Department of Ophthalmology Pusan National University Yangsan Hospital Yangsan Korea
| | - Young Lee
- Veterans Medical Research Institute Veterans Health Service Medical Center Seoul Korea
| | - Je Hyun Seo
- Veterans Medical Research Institute Veterans Health Service Medical Center Seoul Korea
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13
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Singh N, Haider NB. Microbiota, Microbiome, and Retinal Diseases. Int Ophthalmol Clin 2022; 62:197-214. [PMID: 35325919 DOI: 10.1097/iio.0000000000000418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Hatcher JB, de Castro-Abeger A, LaRue RW, Hingorani M, Mawn L, Donahue SP, Sternberg P, Shieh C. MRSA Decolonization and the Eye: A Potential New Tool for Ophthalmologists. Semin Ophthalmol 2022; 37:541-553. [DOI: 10.1080/08820538.2022.2039220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Jeremy B Hatcher
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Alex de Castro-Abeger
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Richard W LaRue
- Department of Medicine, Division of Infectious Disease, Vanderbilt Medical Center, Nashville, TN, United States
| | - Melanie Hingorani
- Department of Paediatrics, Moorfields Eye Hospital, NHS Foundation Trust, London, UK
| | - Louise Mawn
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Sean P Donahue
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Paul Sternberg
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Christine Shieh
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, United States
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15
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de Paiva CS, St Leger AJ, Caspi RR. Mucosal immunology of the ocular surface. Mucosal Immunol 2022; 15:1143-57. [PMID: 36002743 DOI: 10.1038/s41385-022-00551-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/26/2022] [Accepted: 06/10/2022] [Indexed: 02/04/2023]
Abstract
The eye is a sensory organ exposed to the environment and protected by a mucosal tissue barrier. While it shares a number of features with other mucosal tissues, the ocular mucosal system, composed of the conjunctiva, Meibomian glands, and lacrimal glands, is specialized to address the unique needs of (a) lubrication and (b) host defense of the ocular surface. Not surprisingly, most challenges, physical and immunological, to the homeostasis of the eye fall into those two categories. Dry eye, a dysfunction of the lacrimal glands and/or Meibomian glands, which can both cause, or arise from, sensory defects, including those caused by corneal herpes virus infection, serve as examples of these perturbations and will be discussed ahead. To preserve vision, dense neuronal and immune networks sense various stimuli and orchestrate responses, which must be tightly controlled to provide protection, while simultaneously minimizing collateral damage. All this happens against the backdrop of, and can be modified by, the microorganisms that colonize the ocular mucosa long term, or that are simply transient passengers introduced from the environment. This review will attempt to synthesize the existing knowledge and develop trends in the study of the unique mucosal and immune elements of the ocular surface.
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16
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Tuft S, Somerville TF, Li JPO, Neal T, De S, Horsburgh MJ, Fothergill JL, Foulkes D, Kaye S. Bacterial keratitis: identifying the areas of clinical uncertainty. Prog Retin Eye Res 2021; 89:101031. [PMID: 34915112 DOI: 10.1016/j.preteyeres.2021.101031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/24/2021] [Accepted: 11/29/2021] [Indexed: 12/12/2022]
Abstract
Bacterial keratitis is a common corneal infection that is treated with topical antimicrobials. By the time of presentation there may already be severe visual loss from corneal ulceration and opacity, which may persist despite treatment. There are significant differences in the associated risk factors and the bacterial isolates between high income and low- or middle-income countries, so that general management guidelines may not be appropriate. Although the diagnosis of bacterial keratitis may seem intuitive there are multiple uncertainties about the criteria that are used, which impacts the interpretation of investigations and recruitment to clinical studies. Importantly, the concept that bacterial keratitis can only be confirmed by culture ignores the approximately 50% of cases clinically consistent with bacterial keratitis in which investigations are negative. The aetiology of these culture-negative cases is unknown. Currently, the estimation of bacterial susceptibility to antimicrobials is based on data from systemic administration and achievable serum or tissue concentrations, rather than relevant corneal concentrations and biological activity in the cornea. The provision to the clinician of minimum inhibitory concentrations of the antimicrobials for the isolated bacteria would be an important step forward. An increase in the prevalence of antimicrobial resistance is a concern, but the effect this has on disease outcomes is yet unclear. Virulence factors are not routinely assessed although they may affect the pathogenicity of bacteria within species and affect outcomes. New technologies have been developed to detect and kill bacteria, and their application to bacterial keratitis is discussed. In this review we present the multiple areas of clinical uncertainty that hamper research and the clinical management of bacterial keratitis, and we address some of the assumptions and dogma that have become established in the literature.
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Affiliation(s)
- Stephen Tuft
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London, EC1V 2PD, UK.
| | - Tobi F Somerville
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Ji-Peng Olivia Li
- Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London, EC1V 2PD, UK.
| | - Timothy Neal
- Department of Clinical Microbiology, Liverpool Clinical Laboratories, Liverpool University Hospital NHS Foundation Trust, Prescot Street, Liverpool, L7 8XP, UK.
| | - Surjo De
- Department of Clinical Microbiology, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, UK.
| | - Malcolm J Horsburgh
- Department of Infection and Microbiomes, University of Liverpool, Crown Street, Liverpool, L69 7BX, UK.
| | - Joanne L Fothergill
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Daniel Foulkes
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | - Stephen Kaye
- Department of Eye and Vision Sciences, University of Liverpool, 6 West Derby Street, Liverpool, L7 8TX, UK.
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17
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Weitzman CL, Rostama B, Thomason CA, May M, Belden LK, Hawley DM. Experimental test of microbiome protection across pathogen doses reveals importance of resident microbiome composition. FEMS Microbiol Ecol 2021; 97:6385755. [PMID: 34626186 DOI: 10.1093/femsec/fiab141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/07/2021] [Indexed: 01/04/2023] Open
Abstract
The commensal microbes inhabiting a host tissue can interact with invading pathogens and host physiology in ways that alter pathogen growth and disease manifestation. Prior work in house finches (Haemorhous mexicanus) found that resident ocular microbiomes were protective against conjunctival infection and disease caused by a relatively high dose of Mycoplasma gallisepticum. Here, we used wild-caught house finches to experimentally examine whether protective effects of the resident ocular microbiome vary with the dose of invading pathogen. We hypothesized that commensal protection would be strongest at low M. gallisepticum inoculation doses because the resident microbiome would be less disrupted by invading pathogen. Our five M. gallisepticum dose treatments were fully factorial with an antibiotic treatment to perturb resident microbes just prior to M. gallisepticum inoculation. Unexpectedly, we found no indication of protective effects of the resident microbiome at any pathogen inoculation dose, which was inconsistent with the prior work. The ocular bacterial communities at the beginning of our experiment differed significantly from those previously reported in local wild-caught house finches, likely causing this discrepancy. These variable results underscore that microbiome-based protection in natural systems can be context dependent, and natural variation in community composition may alter the function of resident microbiomes in free-living animals.
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Affiliation(s)
- Chava L Weitzman
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
| | - Bahman Rostama
- Department of Biomedical Sciences, University of New England, Biddeford - 04005, ME, USA
| | - Courtney A Thomason
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA.,Division of Remediation, Tennessee Department of Environment and Conservation, Oak Ridge - 37830, TN, USA
| | - Meghan May
- Department of Biomedical Sciences, University of New England, Biddeford - 04005, ME, USA
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
| | - Dana M Hawley
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
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18
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Katzka W, Dong TS, Luu K, Lagishetty V, Sedighian F, Arias-Jayo N, Jacobs JP, Hsu HY. The Ocular Microbiome Is Altered by Sampling Modality and Age. Transl Vis Sci Technol 2021; 10:24. [PMID: 34661621 PMCID: PMC8525833 DOI: 10.1167/tvst.10.12.24] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Background Studies of the ocular microbiome have used a variety of sampling techniques, but no study has directly compared different sampling methods applied to the same eyes to one another or to a reference standard of corneal epithelial biopsy. We addressed this lack by comparing the microbiome from three conjunctival swabs with those of corneal epithelial biopsy. Methods Twelve eyes (11 patients) were swabbed by calcium alginate swab, cotton-tipped applicator, and Weck-Cel cellulose sponge before a corneal epithelial biopsy (48 samples). We then performed 16S rRNA gene sequencing and universal 16S rRNA gene real-time polymerase chain reaction. Negative/blank controls were used to eliminate contaminants. An analysis was performed to examine the concordance of the three swab types to corneal epithelial biopsy. The effect of patient age on the ocular microbiome as determined by epithelial biopsy was also examined. Results The ocular microbiome from corneal epithelial biopsies consisted of 31 genera with a relative abundance of 1% or more, including Weisella, Corynebacterium, and Pseudomonas. Of the three swab types, Weck-Cel differed the most from corneal biopsies based on beta-diversity analysis. Cotton swabs were unable to capture the Bacteroides population seen on epithelial biopsy. Therefore, calcium alginate swabs seemed to be the closest to epithelial biopsies. Older patients (≥65 years old) had higher alpha diversity (P < 0.05) than younger patients. Differential abundance testing showed that there were 18 genera that were differentially abundant between the two age groups, including Streptococcus and eight members of the Proteobacteria phylum. Conclusions We demonstrate that ocular sampling method and patient age can greatly affect the outcome of sequencing-based analysis of the ocular microbiome. Translational Relevance By understanding the impact of different sampling methods on the results obtained from the ocular surface microbiome, future research on the topic will be more reproducible, leading to a better understanding of ocular surface microbiome in health and disease.
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Affiliation(s)
- William Katzka
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,UCLA Microbiome Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Tien S Dong
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,UCLA Microbiome Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Division of Gastroenterology, Hepatology and Parenteral Nutrition, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Department of Medicine, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Kayti Luu
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,UCLA Microbiome Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Division of Gastroenterology, Hepatology and Parenteral Nutrition, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Department of Medicine, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Venu Lagishetty
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,UCLA Microbiome Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Division of Gastroenterology, Hepatology and Parenteral Nutrition, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Department of Medicine, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Farzaneh Sedighian
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,UCLA Microbiome Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Nerea Arias-Jayo
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,UCLA Microbiome Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Jonathan P Jacobs
- The Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,UCLA Microbiome Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Division of Gastroenterology, Hepatology and Parenteral Nutrition, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Department of Medicine, Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Hugo Y Hsu
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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19
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Valentine L, Norris MR, Bielory L. Comparison of structural components and functional mechanisms within the skin vs. the conjunctival surface. Curr Opin Allergy Clin Immunol 2021; 21:472-9. [PMID: 34387279 DOI: 10.1097/ACI.0000000000000775] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE OF REVIEW The purpose of this review is to highlight and compare the structural and functional differences between the ocular surface and the skin. The goal is to further understand how these components interact from an immunobiological standpoint, which may inform future therapeutic uses. RECENT FINDINGS Treatment agents, such as Dupilumab and Apremilast are traditionally indicated for integumentary conditions, such as atopic dermatitis and psoriasis, respectively. Both were also found to have potent effects on the conjunctival surface and ocular glands, which may be attributed to the similarities in structure. SUMMARY Surfaces of the eyes and the skin are found to have similar composition in terms of immunohistology, steroidogenic properties, and allergic mechanisms. These translate directly into both the adverse effects and therapeutic benefits that overlap when treating these surfaces.
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20
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Abstract
Bacterial infections of the cornea, or bacterial keratitis (BK), are notorious for causing rapidly fulminant disease and permanent vision loss, even among treated patients. In the last sixty years, dramatic upward trajectories in the frequency of BK have been observed internationally, driven in large part by the commercialization of hydrogel contact lenses in the late 1960s. Despite this worsening burden of disease, current evidence-based therapies for BK - including broad-spectrum topical antibiotics and, if indicated, topical corticosteroids - fail to salvage vision in a substantial proportion of affected patients. Amid growing concerns of rapidly diminishing antibiotic utility, there has been renewed interest in urgently needed novel treatments that may improve clinical outcomes on an individual and public health level. Bridging the translational gap in the care of BK requires the identification of new therapeutic targets and rational treatment design, but neither of these aims can be achieved without understanding the complex biological processes that determine how bacterial corneal infections arise, progress, and resolve. In this chapter, we synthesize the current wealth of human and animal experimental data that now inform our understanding of basic BK pathophysiology, in context with modern concepts in ocular immunology and microbiology. By identifying the key molecular determinants of clinical disease, we explore how novel treatments can be developed and translated into routine patient care.
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Affiliation(s)
- Lawson Ung
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - James Chodosh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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21
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Siegal N, Gutowski M, Akileswaran L, Beauchamp NJ 3rd, Ding LC, Chambers CB, Van Gelder RN. Elevated levels of Merkel cell polyoma virus in the anophthalmic conjunctiva. Sci Rep 2021; 11:15366. [PMID: 34321490 DOI: 10.1038/s41598-021-92642-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 06/03/2021] [Indexed: 01/09/2023] Open
Abstract
The human ocular surface hosts a paucibacterial resident microbiome and virome. The factors contributing to homeostasis of this mucosal community are presently unknown. To determine the impact of ocular enucleation and prosthesis placement on the ocular surface microbiome, we sampled conjunctival swabs from 20 anophthalmic and 20 fellow-eye intact conjunctiva. DNA was extracted and subjected to quantitative 16S rDNA PCR, biome representational karyotyping (BRiSK), and quantitative PCR (qPCR) confirmation of specific organisms. 16S ribosomal qPCR revealed equivalent bacterial loads between conditions. Biome representational in silico karyotyping (BRiSK) demonstrated comparable bacterial fauna between anophthalmic and intact conjunctiva. Both torque teno virus and Merkel cell polyoma virus (MCPyV) were detected frequently in healthy and anophthalmic conjunctiva. By qPCR, MCPyV was detected in 19/20 anophthalmic samples compared with 5/20 fellow eyes. MCPyV copy number averaged 891 copies/ng in anophthalmic conjunctiva compared with 193 copies/ng in fellow eyes (p < 0.001). These results suggest that enucleation and prosthesis placement affect the ocular surface flora, particularly for the resident virome. As MCPyV has been shown to be the etiologic cause of Merkel cell carcinoma, understanding the mechanisms by which the ocular surface regulates this virus may have clinical importance.
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22
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Lim SH, Shin JH, Lee JW, Lee Y, Seo JH. Differences in the eyelid and buccal microbiome of glaucoma patients receiving long-term administration of prostaglandin analog drops. Graefes Arch Clin Exp Ophthalmol 2021; 259:3055-3065. [PMID: 33961112 DOI: 10.1007/s00417-021-05218-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/13/2021] [Accepted: 04/21/2021] [Indexed: 12/01/2022] Open
Abstract
PURPOSE To investigate the differences in the eyelid and buccal microbiomes between patients receiving long-term prostaglandin analogs for open-angle glaucoma (PG-OAG) and naïve-OAG patients by using metagenomics. METHODS Eyelid and buccal samples were collected from 30 PG-OAG and 32 naïve-OAG patients. The taxonomic composition of the microbiome was obtained via 16S rRNA gene sequencing, operational taxonomic unit analysis, and diversity analysis. Differential gene expression analysis (DEG) and Bland-Altman (MA) plots were used to determine taxon differences between the microbiomes of PG-OAG and naïve-OAG patients. RESULTS The eyelid microbiome showed marginally significant differences, while the alpha-diversity of the buccal microbiome showed significant differences between PG-OAG and naïve-OAG patients. However, the beta-diversity of both eyelid and buccal microbiomes was higher in PG-OAG patients than in naïve-OAG patients. The MA plot showed cluster differences in the eyelid microbiome. DEG analysis of the eyelid microbiome revealed various taxa differences, including enrichment of Azomonas, Pseudomonas, and Granulicatella in PG-OAG patients over naïve-OAG patients, as well as significant depletion of Delftia and Rothia. In the buccal microbiome in PG-OAG patients, taxa such as Rikenella and Stenotrophomonas were significantly enriched. CONCLUSION Our findings suggest that the eyelid microbiome differs between PG-OAG and naïve-OAG patients, raising concerns regarding the eyelid environment in patients receiving these drugs. The overexpressed microbiome in the eyelid area suggests that microbiota may change after the administration of glaucoma medications in OAG.
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Affiliation(s)
- Su-Ho Lim
- Department of Ophthalmology, Daegu Veterans Health Service Medical Center, 42835, 60 Wolgok-ro, Dalseo-gu, Daegu, Republic of Korea
| | - Jong Hoon Shin
- Department of Ophthalmology, Pusan National University Yangsan Hospital, 50612, 20 Geumo-ro, Mulgeum-eup, Yangsan, Republic of Korea
| | - Ji-Woong Lee
- Department of Ophthalmology, Pusan National University Hospital, 49241, 179 Gudeok-ro, Seo-gu, Busan, Republic of Korea
| | - Young Lee
- Veterans Medical Research Institute, Veterans Health Service Medical Center , 05368, Jinhwangdo-ro 61-gil 53, Gangdong-gu, Seoul, Republic of Korea
| | - Je Hyun Seo
- Veterans Medical Research Institute, Veterans Health Service Medical Center , 05368, Jinhwangdo-ro 61-gil 53, Gangdong-gu, Seoul, Republic of Korea.
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Tummanapalli SS, Kuppusamy R, Yeo JH, Kumar N, New EJ, Willcox MDP. The role of nitric oxide in ocular surface physiology and pathophysiology. Ocul Surf 2021; 21:37-51. [PMID: 33940170 DOI: 10.1016/j.jtos.2021.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 12/31/2022]
Abstract
Nitric oxide (NO) has a wide array of biological functions including the regulation of vascular tone, neurotransmission, immunomodulation, stimulation of proinflammatory cytokine expression and antimicrobial action. These functions may depend on the type of isoform that is responsible for the synthesis of NO. NO is found in various ocular tissues playing a pivotal role in physiological mechanisms, namely regulating vascular tone in the uvea, retinal blood circulation, aqueous humor dynamics, neurotransmission and phototransduction in retinal layers. Unregulated production of NO in ocular tissues may result in production of toxic superoxide free radicals that participate in ocular diseases such as endotoxin-induced uveitis, ischemic proliferative retinopathy and neurotoxicity of optic nerve head in glaucoma. However, the role of NO on the ocular surface in mediating physiology and pathophysiological processes is not fully understood. Moreover, methods used to measure levels of NO in the biological samples of the ocular surface are not well established due to its rapid oxidation. The purpose of this review is to highlight the role of NO in the physiology and pathophysiology of ocular surface and propose suitable techniques to measure NO levels in ocular surface tissues and tears. This will improve the understanding of NO's role in ocular surface biology and the development of new NO-based therapies to treat various ocular surface diseases. Further, this review summarizes the biochemistry underpinning NO's antimicrobial action.
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Affiliation(s)
| | - Rajesh Kuppusamy
- School of Optometry & Vision Science, University of New South Wales, Australia; School of Chemistry, University of New South Wales, Australia
| | - Jia Hao Yeo
- The University of Sydney, School of Chemistry, NSW, 2006, Australia
| | - Naresh Kumar
- School of Chemistry, University of New South Wales, Australia
| | - Elizabeth J New
- The University of Sydney, School of Chemistry, NSW, 2006, Australia; The University of Sydney Nano Institute (Sydney Nano), The University of Sydney, NSW, 2006, Australia
| | - Mark D P Willcox
- School of Optometry & Vision Science, University of New South Wales, Australia
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Ozkan J, Majzoub ME, Coroneo M, Thomas T, Willcox M. Comparative analysis of ocular surface tissue microbiome in human, mouse, rabbit, and guinea pig. Exp Eye Res 2021; 207:108609. [PMID: 33932398 DOI: 10.1016/j.exer.2021.108609] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/06/2021] [Accepted: 04/21/2021] [Indexed: 01/21/2023]
Abstract
Animal models are a critical element of ocular surface research for investigating therapeutic drops, surgical implants, and infection research. This study was a comparative analysis of the microbial communities on conjunctival tissue samples from humans compared to several commonly used laboratory animals (BALB/c mice, New Zealand white rabbits and IMVS colored stock guinea pigs). Microbial communities were analyzed by extracting total DNA from conjunctival tissue and sequencing the 16 S rRNA gene using the Illumina MiSeq platform. Sequences were quality filtered using the UNOISE pipeline in USEARCH and taxonomically classified using GTDB database. Sequences associated with blank extraction and sampling negative controls were removed with the decontam R software package prior to downstream analysis. There was a difference in the diversity measures of richness (P = 0.0124) and Shannon index (P = 0.0002) between humans and rabbits but not between human, mouse and guinea pigs. There was a difference between the human and any animal for bacterial community structure (P = 0.006). There was a higher degree of similarity between the bacterial composition of the human and mouse samples with each dominated by the phyla Proteobacteria and Firmicutes. The use of mouse models may be more appropriate for studies investigating changes to the ocular microbiome due to interventions such as application of antibiotics due to greater similarities in bacterial community structure and composition to humans.
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Affiliation(s)
- Jerome Ozkan
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia; Centre for Marine Science and Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.
| | - Marwan E Majzoub
- Centre for Marine Science and Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Minas Coroneo
- Department of Ophthalmology, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Torsten Thomas
- Centre for Marine Science and Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Kalaiselvan P, Dutta D, Bhombal F, Konda N, Vaddavalli PK, Sharma S, Stapleton F, Willcox MDP. Ocular microbiota and lens contamination following Mel4 peptide-coated antimicrobial contact lens (MACL) extended wear. Cont Lens Anterior Eye 2021;:101431. [PMID: 33676840 DOI: 10.1016/j.clae.2021.02.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/31/2021] [Accepted: 02/20/2021] [Indexed: 12/28/2022]
Abstract
PURPOSE The purpose of this study was to investigate the effect of Mel4 antimicrobial peptide-coated contact lenses (MACL) on the microbiota of the conjunctiva and lenses during three months of extended wear. METHODS One hundred and seventy-six participants were recruited into a randomised, contralateral, double masked, biweekly extended wear MACL and uncoated control lens trial. At the one month and 3-month visit, the conjunctival microbiota was sampled using sterile cotton swabs and contact lenses were collected aseptically. Standard microbiological procedures were employed for culture of the swabs and contact lenses and identification of the isolated microorganisms. RESULTS Gram-positive bacteria (predominantly coagulase-negative staphylococci) were the most frequently isolated microbes from both contact lenses and conjunctiva. There was no difference in the frequency of isolation of most bacteria or fungi from the conjunctival swabs of eyes wearing either MACL or control lenses. The only exception was a higher frequency of eyes harbouring Staphylococcus arlettae when wearing control lenses (5%) versus MACL (<1%) (p = 0.002). There was no significant difference in the frequency of microbes isolated from MACL or control contact lenses. There were also no differences between lens types in the frequency of isolation of >1 microbial type per sampling occasion for either conjunctiva swabs or contact lenses. CONCLUSION MACL wear did not change the conjunctival microbiota during extended wear, and the types of microbes isolated from MACL were similar to those isolated from control lenses.
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26
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Szczotka-Flynn LB, Shovlin JP, Schnider CM, Caffery BE, Alfonso EC, Carnt NA, Chalmers RL, Collier S, Jacobs DS, Joslin CE, Kroken AR, Lakkis C, Pearlman E, Schein OD, Stapleton F, Tu E, Willcox MDP. American Academy of Optometry Microbial Keratitis Think Tank. Optom Vis Sci 2021; 98:182-198. [PMID: 33771951 PMCID: PMC8075116 DOI: 10.1097/opx.0000000000001664] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
SIGNIFICANCE Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious infections associated with Acanthamoeba and fungi. The growing use of contact lenses in children demands our attention with surveillance and case-control studies. PURPOSE The American Academy of Optometry (AAO) gathered researchers and key opinion leaders from around the world to discuss contact lens-associated microbial keratitis at the 2019 AAO Annual Meeting. METHODS Experts presented within four sessions. Session 1 covered the epidemiology of microbial keratitis, pathogenesis of Pseudomonas aeruginosa, and the role of lens care systems and storage cases in corneal disease. Session 2 covered nonbacterial forms of keratitis in contact lens wearers. Session 3 covered future needs, challenges, and research questions in relation to microbial keratitis in youth and myopia control, microbiome, antimicrobial surfaces, and genetic susceptibility. Session 4 covered compliance and communication imperatives. RESULTS The absolute rate of microbial keratitis has remained very consistent for three decades despite new technologies, and extended wear significantly increases the risk. Improved oxygen delivery afforded by silicone hydrogel lenses has not impacted the rates, and although the introduction of daily disposable lenses has minimized the risk of severe disease, there is no consistent evidence that they have altered the overall rate of microbial keratitis. Overnight orthokeratology lenses may increase the risk of microbial keratitis, especially secondary to Acanthamoeba, in children. Compliance remains a concern and a significant risk factor for disease. New insights into host microbiome and genetic susceptibility may uncover new theories. More studies such as case-control designs suited for rare diseases and registries are needed. CONCLUSIONS The first annual AAO Think Tank acknowledged that the risk of microbial keratitis has not decreased over decades, despite innovation. Important questions and research directions remain.
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Affiliation(s)
| | | | | | | | - Eduardo C Alfonso
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Nicole A Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | | | - Sarah Collier
- U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Deborah S Jacobs
- Massachusetts Eye and Ear, Cornea Service, Harvard Medical School, Boston, Massachusetts
| | - Charlotte E Joslin
- Department of Ophthalmology and Visual Science, College of Medicine, Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, Illinois
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, Berkeley, California
| | | | - Eric Pearlman
- Departments of Ophthalmology, and Physiology and Biophysics, University of California, Irvine, Irvine, California
| | - Oliver D Schein
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Fiona Stapleton
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Elmer Tu
- University of Illinois Eye and Ear Infirmary, Chicago, Illinois
| | - Mark D P Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
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Ranjith K, Sharma S, Shivaji S. Microbes of the human eye: Microbiome, antimicrobial resistance and biofilm formation. Exp Eye Res 2021; 205:108476. [PMID: 33549582 DOI: 10.1016/j.exer.2021.108476] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/21/2023]
Abstract
BACKGROUND The review focuses on the bacteria associated with the human eye using the dual approach of detecting cultivable bacteria and the total microbiome using next generation sequencing. The purpose of this review was to highlight the connection between antimicrobial resistance and biofilm formation in ocular bacteria. METHODS Pubmed was used as the source to catalogue culturable bacteria and ocular microbiomes associated with the normal eyes and those with ocular diseases, to ascertain the emergence of anti-microbial resistance with special reference to biofilm formation. RESULTS This review highlights the genetic strategies used by microorganisms to evade the lethal effects of anti-microbial agents by tracing the connections between candidate genes and biofilm formation. CONCLUSION The eye has its own microbiome which needs to be extensively studied under different physiological conditions; data on eye microbiomes of people from different ethnicities, geographical regions etc. are also needed to understand how these microbiomes affect ocular health.
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Affiliation(s)
- Konduri Ranjith
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India.
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India.
| | - Sisinthy Shivaji
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India.
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28
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Delbeke H, Younas S, Casteels I, Joossens M. Current knowledge on the human eye microbiome: a systematic review of available amplicon and metagenomic sequencing data. Acta Ophthalmol 2021; 99:16-25. [PMID: 32602257 DOI: 10.1111/aos.14508] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/06/2020] [Accepted: 05/21/2020] [Indexed: 12/23/2022]
Abstract
Insights in the ocular surface microbiome are still at an early stage and many more questions remain unanswered compared with other human-associated microbial communities. The current knowledge on the human microbiome changed our viewpoint on bacteria and human health and significantly enhanced our understanding of human pathophysiology. Also in ocular medicine, microbiome research might impact treatment. Here, we summarize the current knowledge on ocular microbiome research with a particular focus on potential confounding factors and their effects on microbiome composition. Moreover, we present the ocular surface core microbiome based on current available data and defined it as genera present in almost half of the published control cohorts with a relative abundance of at least 1%.
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Affiliation(s)
- Heleen Delbeke
- Department of Ophthalmology University Hospitals Leuven Leuven Belgium
| | - Saif Younas
- Department of Internal Medicine University Hospitals Leuven Leuven Belgium
| | - Ingele Casteels
- Department of Ophthalmology University Hospitals Leuven Leuven Belgium
| | - Marie Joossens
- Department of Molecular Bacteriology REGA institute Catholic University Leuven Leuven Belgium
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29
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Abstract
The ocular surface is exposed continuously to the environment and, as a consequence, to a variety of different microbes. After the results of the Human Microbiome Project became publicly available, international research groups started to focus interest on exploring the ocular surface microbiome and its physiopathological relationship to the eye. For example, numerous research studies the existence of the ocular surface's bacterial flora, typically gathering cultures from healthy patients and finding few variations in the bacterial species. More recently, culture-independent methods, including 16S ribosomal ribonucleic acid (rRNA) gene sequencing, are being used to define the ocular microbiome. These newer methods suggest that the microbial communities have a greater diversity than previously reported. These communities seem to serve an immune-modulating function and maintain relationships with other microbes and organs, even distant ones. This review summarizes the literature exploring the ocular microbiome, both in health and in different diseases.
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Affiliation(s)
- José Álvaro P Gomes
- Department of Ophthalmology and Visual Sciences, Federal University of Sao Paulo, UNIFESP, Brazil
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30
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Tsai JC, Casteneda G, Lee A, Dereschuk K, Li WT, Chakladar J, Lombardi AF, Ongkeko WM, Chang EY. Identification and Characterization of the Intra-Articular Microbiome in the Osteoarthritic Knee. Int J Mol Sci 2020; 21:E8618. [PMID: 33207573 DOI: 10.3390/ijms21228618] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/04/2020] [Accepted: 11/13/2020] [Indexed: 12/21/2022] Open
Abstract
Osteoarthritis (OA) is the most common joint disorder in the United States, and the gut microbiome has recently emerged as a potential etiologic factor in OA development. Recent studies have shown that a microbiome is present at joint synovia. Therefore, we aimed to characterize the intra-articular microbiome within osteoarthritic synovia and to illustrate its role in OA disease progression. RNA-sequencing data from OA patient synovial tissue was aligned to a library of microbial reference genomes to identify microbial reads indicative of microbial abundance. Microbial abundance data of OA and normal samples was compared to identify differentially abundant microbes. We computationally explored the correlation of differentially abundant microbes to immunological gene signatures, immune signaling pathways, and immune cell infiltration. We found that microbes correlated to OA are related to dysregulation of two main functional pathways: increased inflammation-induced extracellular matrix remodeling and decreased cell signaling pathways crucial for joint and immune function. We also confirmed that the differentially abundant and biologically relevant microbes we had identified were not contaminants. Collectively, our findings contribute to the understanding of the human microbiome, well-known OA risk factors, and the role microbes play in OA pathogenesis. In conclusion, we present previously undiscovered microbes implicated in the OA disease progression that may be useful for future treatment purposes.
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31
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Flores Bueso Y, Walker SP, Tangney M. Characterization of FFPE-induced bacterial DNA damage and development of a repair method. Biol Methods Protoc 2020; 5:bpaa015. [PMID: 33072872 PMCID: PMC7548031 DOI: 10.1093/biomethods/bpaa015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/15/2020] [Accepted: 07/18/2020] [Indexed: 01/13/2023] Open
Abstract
Formalin-fixed, paraffin-embedded (FFPE) specimens have huge potential as source material in the field of human microbiome research. However, the effects of FFPE processing on bacterial DNA remain uncharacterized. Any effects are relevant for microbiome studies, where DNA template is often minimal and sequences studied are not limited to one genome. As such, we aimed to both characterize this FFPE-induced bacterial DNA damage and develop strategies to reduce and repair this damage. Our analyses indicate that bacterial FFPE DNA is highly fragmented, a poor template for PCR, crosslinked and bears sequence artefacts derived predominantly from oxidative DNA damage. Two strategies to reduce this damage were devised – an optimized decrosslinking procedure reducing sequence artefacts generated by high-temperature incubation, and secondly, an in vitro reconstitution of the base excision repair pathway. As evidenced by whole genome sequencing, treatment with these strategies significantly increased fragment length, reduced the appearance of sequence artefacts and improved the sequencing readability of bacterial and mammalian FFPE DNA. This study provides a new understanding of the condition of bacterial DNA in FFPE specimens and how this impacts downstream analyses, in addition to a strategy to improve the sequencing quality of bacterial and possibly mammalian FFPE DNA.
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Affiliation(s)
- Yensi Flores Bueso
- CancerResearch@UCC, University College Cork, Cork, T12 XF62, Ireland.,SynBioCentre, University College Cork, Cork, T12 XF62, Ireland.,APC Microbiome Ireland, University College Cork, Cork, T12 YT20, Ireland
| | - Sidney P Walker
- CancerResearch@UCC, University College Cork, Cork, T12 XF62, Ireland.,SynBioCentre, University College Cork, Cork, T12 XF62, Ireland.,APC Microbiome Ireland, University College Cork, Cork, T12 YT20, Ireland
| | - Mark Tangney
- CancerResearch@UCC, University College Cork, Cork, T12 XF62, Ireland.,SynBioCentre, University College Cork, Cork, T12 XF62, Ireland.,APC Microbiome Ireland, University College Cork, Cork, T12 YT20, Ireland
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Flores Bueso Y, Walker SP, Hogan G, Claesson MJ, Tangney M. Protoblock - A biological standard for formalin fixed samples. Microbiome 2020; 8:122. [PMID: 32828122 PMCID: PMC7443293 DOI: 10.1186/s40168-020-00901-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/24/2020] [Indexed: 05/16/2023]
Abstract
BACKGROUND Formalin-fixed, paraffin-embedded (FFPE) tissue is the gold standard in pathology tissue storage, representing the largest collections of patient material. Their reliable use for DNA analyses could open a trove of potential samples for research and are currently being recognised as a viable source material for bacterial analysis. There are several key features which limit bacterial-related data generation from this material: (i) DNA damage inherent to the fixing process, (ii) low bacterial biomass that increases the vulnerability to contamination and exacerbates the host DNA effects and (iii) lack of suitable DNA extraction methods, leading to data bias. The development and systematic use of reliable standards is a key priority for microbiome research. More than perhaps any other sample type, FFPE material urgently requires the development of standards to ensure the validity of results and to promote reproducibility. RESULTS To address these limitations and concerns, we have developed the Protoblock as a biological standard for FFPE tissue-based research and method optimisation. This is a novel system designed to generate bespoke mock FFPE 'blocks' with a cell content that is user-defined and which undergoes the same treatment conditions as clinical FFPE tissues. The 'Protoblock' features a mix of formalin-fixed cells, of known number, embedded in an agar matrix which is solidified to form a defined shape that is paraffin embedded. The contents of various Protoblocks populated with mammalian and bacterial cells were verified by microscopy. The quantity and condition of DNA purified from blocks was evaluated by qPCR, 16S rRNA gene amplicon sequencing and whole genome sequencing. These analyses validated the capability of the Protoblock system to determine the extent to which each of the three stated confounding features impacts on eventual analysis of cellular DNA present in FFPE samples. CONCLUSION The Protoblock provides a representation of biological material after FFPE treatment. Use of this standard will greatly assist the stratification of biological variations detected into those legitimately resulting from experimental conditions, and those that are artefacts of the processed nature of the samples, thus enabling users to relate the outputs of laboratory analyses to reality. Video Abstract.
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Affiliation(s)
- Yensi Flores Bueso
- CancerResearch@UCC, University College Cork, Cork, Ireland
- SynBioCentre, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Sidney P Walker
- CancerResearch@UCC, University College Cork, Cork, Ireland
- SynBioCentre, University College Cork, Cork, Ireland
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- School of Microbiology, University College Cork, Cork, Ireland
| | - Glenn Hogan
- CancerResearch@UCC, University College Cork, Cork, Ireland
- SynBioCentre, University College Cork, Cork, Ireland
| | - Marcus J Claesson
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- School of Microbiology, University College Cork, Cork, Ireland
| | - Mark Tangney
- CancerResearch@UCC, University College Cork, Cork, Ireland.
- SynBioCentre, University College Cork, Cork, Ireland.
- APC Microbiome Ireland, University College Cork, Cork, Ireland.
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Avetisov SE, Abramova ND, Gogoleva NE, Gusev OA, Mitichkina TS, Novikov IA, Subbot AM, Shagimardanova EI. [Rational strategy for studying microbiome of the ocular surface of people using hard contact lenses by method of 16S rRNA gene metabarcoding]. Vestn Oftalmol 2020; 136:3-9. [PMID: 32504470 DOI: 10.17116/oftalma20201360313] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study is based on the hypothesis that high taxonomic diversity of bacteria detectable on the eye surface by molecular genetic methods is attributed to the high level of its contamination by skin microflora. Such contamination would make it problematic to identify the fractions of real ocular surface microbiome, which remains behind the one-percent cut-off threshold adopted in the metagenomic analysis. Hard contact lenses for long-wearing act as a physical filter preventing DNA contamination from random microorganisms, and at the same time providing adhesion to the living cells of bacteria and fungi. To confirm this assumption, a detailed analysis of references was carried out, supplemented by original laboratory research. MATERIAL AND METHODS The analysis included 16 hard contact lenses obtained from 11 patients with impaired refraction (myopia). Additionally, conjunctival mucosa scrapings were collected from 42 patients. Samples were cross-analyzed by 16S rRNA gene sequencing using 454 GS Junior (Ion Torrent) and Illumina MiSeq platforms. RESULTS Results obtained by the Illumina platform (analysis of the V3-V4 variable region of the 16S rRNA gene) showed better convergence with the data of culture tests reported in the literature. The major microorganism groups found were: Acinetobacter (39%), Gluconacetobacter (10.8%), Propionibacterium (9.3%), Corynebacterium (9.3%), Staphylococcus (7.2%), Streptococcus (7%), Pseudomonas (4.1%), Micrococcus (3.3%), Yersinia (3%), Chondromyces (2.4%), Serratia (2.3%), and Bacillus (2.1%). Analysis of the samples obtained directly from the mucosa revealed dominance of typical skin-associated microorganisms. CONCLUSION The present study proposes a contamination-reduction algorithm for microbiological testing of the ocular surface using hard contact lenses for prolonged wearing as a carrier for microbial DNA.
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Affiliation(s)
- S E Avetisov
- Research Institute of Eye Diseases, Moscow, Russia.,I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - N D Abramova
- Research Institute of Eye Diseases, Moscow, Russia
| | - N E Gogoleva
- Kazan Institute of Biochemistry and Biophysics - stand-alone branch of Kazan Scientific Center of RAS, Kazan, Russia.,Kazan Federal University (Volga Region), Institute of Fundamental Medicine and Biology, Kazan, Russia
| | - O A Gusev
- RIKEN-KFU Translational Genomics Unit, RIKEN Cluster for Science, Technology and Innovation Hub, Yokohama City, Japan
| | | | - I A Novikov
- Research Institute of Eye Diseases, Moscow, Russia
| | - A M Subbot
- Research Institute of Eye Diseases, Moscow, Russia
| | - E I Shagimardanova
- Kazan Federal University (Volga Region), Institute of Fundamental Medicine and Biology, Kazan, Russia
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34
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Zilliox MJ, Gange WS, Kuffel G, Mores CR, Joyce C, de Bustros P, Bouchard CS. Assessing the ocular surface microbiome in severe ocular surface diseases. Ocul Surf 2020; 18:706-12. [PMID: 32717380 DOI: 10.1016/j.jtos.2020.07.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 07/05/2020] [Accepted: 07/09/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE There is growing evidence for a critical role of the microbiome in ocular health and disease. We performed a prospective, observational study to characterize the ocular surface microbiome (OSM) in four chronic ocular surface diseases (OSDs) and healthy controls. METHODS Sterile swabs were used to collect samples from each eye of 39 patients (78 eyes). Sterile technique and multiple controls were used to assess contamination during DNA extraction, amplification and sequencing. Concurrent use of topical antibiotics, steroids, and bandage contact lenses (BCLs) was documented. RESULTS Despite the low biomass of the ocular surface, 47/78 (60%) eyes sampled had positive sequencing reads. We observed that half of patients (8/17, 47%) had distinct microbiomes in each eye. Healthy controls had a Lactobacillus/Streptococcus mixture or significant Corynebacterium. Staphylococcus predominated in 4/7 (57%) patients with Stevens-Johnson Syndrome (SJS) in at least one eye, compared to 0/10 healthy controls. Interestingly, 8/11 (73%) eyes with SJS were using BCLs, including 4/5 (80%) eyes dominated by Staphylococcus. Lax eyelid syndrome (LES) and Dry Eye Disease (DED) patients had similar OSMs, with Corynebacterium being the most prevalent bacteria. Alpha diversity was higher in controls and ocular graft-vs-host (oGVHD) patients compared to the other OSDs. CONCLUSIONS Only 50% of the 39 patients had similar microbiomes in each eye. A majority of healthy eyes had a Lactobacillus/Streptococcus mix or Corynebacterium microbiome. Staphylococcus predominated in SJS, Lactobacillus in oGVHD, and Corynebacterium in DED and LES. There may be an association between different OSDs and the microbiome.
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Ozkan J, Coroneo M, Sandbach J, Subedi D, Willcox M, Thomas T. Bacterial contamination of intravitreal needles by the ocular surface microbiome. Ocul Surf 2020; 19:169-175. [PMID: 32497656 DOI: 10.1016/j.jtos.2020.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 05/15/2020] [Accepted: 05/15/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE The ocular surface microbiota are recognised as one of causative microorganisms in post-procedural endophthalmitis but in many cases the vitreous tap is culture negative. This study investigated bacterial contamination of intravitreal (IVT) needles using multiple approaches covering culturing, 16S rRNA gene sequencing, fluorescent in situ hybridisation (FISH) and scanning electron microscopy (SEM). METHODS IVT needles were obtained immediately after injection from patients undergoing treatment for predominantly age-related macular degeneration. Eighteen needles were analysed by culturing on chocolate blood agar. In addition, 40 needles were analysed by extracting DNA and paired-end sequencing of the 16S rRNA gene. Sequences were quality filtered (USEARCH), taxonomically classified (SILVA) and contaminant filtered (DECONTAM). Nine needles were analysed by either FISH using the bacterial probe EUB338 or SEM. RESULTS Using culturing, three bacteria were identified from 5 of 18 needles (28%) - Kocuria kristinae, Staphylococcus hominis and Sphingomonas paucimobilis. The negative control needles showed no growth. Following rigorous data filtering, bacterial community analysis using 16S rRNA gene sequencing showed the presence of predominantly Corynebacterium but also Pseudomonas, Acinetobacter, Sphingomonas, Staphylococcus and Bacillus on the needles. Cocci-shaped cells in a tetrad formation were observed using FISH, while SEM images showed cocci-shaped bacteria in pairs and irregular tetrads. CONCLUSIONS The study showed evidence for a large diversity of bacteria on IVT needles and visually confirmed their adherence. The diversity was similar to that found on the ocular surface and in conjunctival tissue. This suggests the risk of exogenous endophthalmitis remains even with sterilization of the conjunctival surface.
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Affiliation(s)
- Jerome Ozkan
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia; School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.
| | - Minas Coroneo
- Department of Ophthalmology, Prince of Wales Hospital, University of New South Wales, Sydney, Australia
| | - Jennifer Sandbach
- Department of Ophthalmology, Prince of Wales Hospital, University of New South Wales, Sydney, Australia
| | - Dinesh Subedi
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Torsten Thomas
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
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Okonkwo A, Rimmer V, Walkden A, Brahma A, Carley F, Mcbain AJ, Radhakrishnan H. Next-Generation Sequencing of the Ocular Surface Microbiome: In Health, Contact Lens Wear, Diabetes, Trachoma, and Dry Eye. Eye Contact Lens 2020; 46:254-61. [DOI: 10.1097/icl.0000000000000697] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Abstract
Purpose The purpose of this study was to investigate the microbiome in the meibum, conjunctival sac, and eyelid skin in young and elderly healthy subjects, and analyze the effect that age, sex, and region have on microbiome composition. Methods This study involved 36 healthy subjects (young-age subjects: 9 men/9 women, age range: 20–35 years; elderly age subjects: 9 men/9 women, age range: 60–70 years). In all subjects, lower-eyelid meibum, lower conjunctival sac, and lower-eyelid skin specimens were collected from one eye, and then stored at –20°C. Taxonomic composition of the microbiome was obtained via 16S rRNA gene sequencing, and then analyzed. Results The meibum microbiome showed a high α-diversity (within-community diversity), particularly in the young subjects. However, in approximately 30% of the elderly subjects, a low-diversity microbiome dominated by Corynebacterium sp. or Neisseriaceae was observed. In the young subjects, the microbiome of the meibum resembled that of the conjunctival-sac, yet in the elderly subjects, the microbiome of the conjunctival-sac became more similar to that of the eyelid skin. The eyelid-skin microbiome was relatively simple, and was typically dominated by Propionibacterium acnes in the young subjects, or by Corynebacterium sp. or Neisseriaceae in the elderly subjects. In both age groups, no significant difference was seen between the men and women in regard to the meibum, conjunctival-sac, and eyelid-skin microbiome. Conclusions Our findings confirmed that the meibum of healthy adult-age subjects harbors highly diverse microbiota, and revealed that the meibum microbiome, especially the decrease of its diversity, alters with aging and may affect the homeostasis of the ocular surface.
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Ung L, Bispo PJM, Doan T, Van Gelder RN, Gilmore MS, Lietman T, Margolis TP, Zegans ME, Lee CS, Chodosh J. Clinical metagenomics for infectious corneal ulcers: Rags to riches? Ocul Surf 2020; 18:1-12. [PMID: 31669750 PMCID: PMC9837861 DOI: 10.1016/j.jtos.2019.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 10/21/2019] [Indexed: 01/17/2023]
Abstract
The emergence of clinical metagenomics as an unbiased, hypothesis-free approach to diagnostic testing is set to fundamentally alter the way infectious diseases are detected. Long envisioned as the solution to the limitations of culture-based conventional microbiology, next generation sequencing methods will soon mature, and our attention will inevitably turn to how they can be applied to areas of medicine which need it most urgently. In ophthalmology, the demand for this technology is particularly pressing for the care of infectious corneal ulcers, where current diagnostic tests may fail to identify a causative organism in over half of cases. However, the optimism found in the budding discourse surrounding clinical metagenomics belies the reality that clinicians and scientists will soon be inundated by oppressive volumes of sequencing data, much of which will be foreign and unfamiliar. Therefore, our success in translating clinical metagenomics is likely to hinge on how we make sense of these data, and understanding its implications for the interpretation and implementation of sequencing into routine clinical care. In this consortium-led review, we provide an outline of these data-related issues and how they may be used to inform technical workflows, with the hope that we may edge closer to realizing the potential of clinical metagenomics for this important unmet need.
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Affiliation(s)
- Lawson Ung
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute and Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Paulo J M Bispo
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute and Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Thuy Doan
- Francis I. Proctor Foundation, Department of Ophthalmology, University of California, San Francisco, CA, USA
| | | | - Michael S Gilmore
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute and Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Thomas Lietman
- Francis I. Proctor Foundation, Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Todd P Margolis
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in Saint Louis, Saint Louis, USA
| | - Michael E Zegans
- Department of Surgery (Ophthalmology), and Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, USA
| | - Cecilia S Lee
- Department of Ophthalmology, University of Washington, Seattle, WA, USA.
| | - James Chodosh
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA; Infectious Disease Institute and Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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Fleiszig SMJ, Kroken AR, Nieto V, Grosser MR, Wan SJ, Metruccio MME, Evans DJ. Contact lens-related corneal infection: Intrinsic resistance and its compromise. Prog Retin Eye Res 2019; 76:100804. [PMID: 31756497 DOI: 10.1016/j.preteyeres.2019.100804] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 11/05/2019] [Accepted: 11/12/2019] [Indexed: 12/20/2022]
Abstract
Contact lenses represent a widely utilized form of vision correction with more than 140 million wearers worldwide. Although generally well-tolerated, contact lenses can cause corneal infection (microbial keratitis), with an approximate annualized incidence ranging from ~2 to ~20 cases per 10,000 wearers, and sometimes resulting in permanent vision loss. Research suggests that the pathogenesis of contact lens-associated microbial keratitis is complex and multifactorial, likely requiring multiple conspiring factors that compromise the intrinsic resistance of a healthy cornea to infection. Here, we outline our perspective of the mechanisms by which contact lens wear sometimes renders the cornea susceptible to infection, focusing primarily on our own research efforts during the past three decades. This has included studies of host factors underlying the constitutive barrier function of the healthy cornea, its response to bacterial challenge when intrinsic resistance is not compromised, pathogen virulence mechanisms, and the effects of contact lens wear that alter the outcome of host-microbe interactions. For almost all of this work, we have utilized the bacterium Pseudomonas aeruginosa because it is the leading cause of lens-related microbial keratitis. While not yet common among corneal isolates, clinical isolates of P. aeruginosa have emerged that are resistant to virtually all currently available antibiotics, leading the United States CDC (Centers for Disease Control) to add P. aeruginosa to its list of most serious threats. Compounding this concern, the development of advanced contact lenses for biosensing and augmented reality, together with the escalating incidence of myopia, could portent an epidemic of vision-threatening corneal infections in the future. Thankfully, technological advances in genomics, proteomics, metabolomics and imaging combined with emerging models of contact lens-associated P. aeruginosa infection hold promise for solving the problem - and possibly life-threatening infections impacting other tissues.
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Affiliation(s)
- Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, CA, USA; Graduate Group in Vision Science, University of California, Berkeley, CA, USA; Graduate Groups in Microbiology and Infectious Diseases & Immunity, University of California, Berkeley, CA, USA.
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, CA, USA
| | - Vincent Nieto
- School of Optometry, University of California, Berkeley, CA, USA
| | | | - Stephanie J Wan
- Graduate Group in Vision Science, University of California, Berkeley, CA, USA
| | | | - David J Evans
- School of Optometry, University of California, Berkeley, CA, USA; College of Pharmacy, Touro University California, Vallejo, CA, USA
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Abstract
This article summarises research undertaken since 1993 in the Willcox laboratory at the University of New South Wales, Sydney on the tear film, its interactions with contact lenses, and the use of tears as a source of biomarkers for ocular and non-ocular diseases. The proteome, lipidome and glycome of tears all contribute to important aspects of the tear film, including its structure, its ability to defend the ocular surface against microbes and to help heal ocular surface injuries. The tear film interacts with contact lenses in vivo and interactions between tears and lenses can affect the biocompatibility of lenses, and may be important in mediating discomfort responses during lens wear. Suggestions are made for follow-up research.
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Affiliation(s)
- Mark Dp Willcox
- School of Optometry and Vision Science, The University of New South Wales, Sydney, New South Wales, Australia
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Sherchand SP, Aiyar A. Ammonia generation by tryptophan synthase drives a key genetic difference between genital and ocular Chlamydia trachomatis isolates. Proc Natl Acad Sci U S A 2019; 116:12468-77. [PMID: 31097582 DOI: 10.1073/pnas.1821652116] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A striking difference between genital and ocular clinical isolates of Chlamydia trachomatis is that only the former express a functional tryptophan synthase and therefore can synthesize tryptophan by indole salvage. Ocular isolates uniformly cannot use indole due to inactivating mutations within tryptophan synthase, indicating a selection against maintaining this enzyme in the ocular environment. Here, we demonstrate that this selection occurs in two steps. First, specific indole derivatives, produced by the human gut microbiome and present in serum, rapidly induce expression of C. trachomatis tryptophan synthase, even under conditions of tryptophan sufficiency. We demonstrate that these indole derivatives function by acting as de-repressors of C. trachomatis TrpR. Second, trp operon de-repression is profoundly deleterious when infected cells are in an indole-deficient environment, because in the absence of indole, tryptophan synthase deaminates serine to pyruvate and ammonia. We have used biochemical and genetic approaches to demonstrate that expression of wild-type tryptophan synthase is required for the bactericidal production of ammonia. Pertinently, although these indole derivatives de-repress the trpRBA operon of C. trachomatis strains with trpA or trpB mutations, no ammonia is produced, and no deleterious effects are observed. Our studies demonstrate that tryptophan synthase can catalyze the ammonia-generating β-elimination reaction within any live bacterium. Our results also likely explain previous observations demonstrating that the same indole derivatives inhibit the growth of other pathogenic bacterial species, and why high serum levels of these indole derivatives are favorable for the prognosis of diseased conditions associated with bacterial dysbiosis.
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Abstract
Aim: The ocular surface is continually exposed to bacteria from the environment and traditional culture-based microbiological studies have isolated a low diversity of microorganisms from this region. The use of culture-independent methods to define the ocular microbiome, primarily involving 16S ribosomal RNA gene sequencing studies, have shown that the microbial communities present on the ocular surface have a greater diversity than previously reported. Method: A review of the literature on ocular microbiome research in health and disease. Results: Molecular techniques have been used to investigate the effect of contact lens wear and disease on the microbiota of the ocular surface and eyelids and the immunoregulatory role of the ocular surface microbiota. Studies have shown that compositional changes in the microbiota occur in ocular surface disorders such as blepharitis, trachoma and dry eye and also suggest a role of the ocular and non-ocular microbiome in retinal disease including age-related macular degeneration, glaucoma, uveitis and diabetic retinopathy. However, ocular microbiome studies need to recognise the potential for contamination to impact findings and carefully control each stage of the experimental procedure and to utilise statistical methods to identify contamination signals. Conclusion: The healthy ocular surface is characterised by a relatively stable, comparatively low diversity microbiome with recent findings that the bacteria of the ocular surface appear to have a role in maintaining homeostasis by modulating immune function.
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Affiliation(s)
- Jerome Ozkan
- a School of Optometry and Vision Science , University of New South Wales , Sydney , Australia.,b School of Biological, Earth and Environmental Sciences , University of New South Wales , Sydney , Australia
| | - Mark D Willcox
- a School of Optometry and Vision Science , University of New South Wales , Sydney , Australia
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Darden JE, Scott EM, Arnold C, Scallan EM, Simon BT, Suchodolski JS. Evaluation of the bacterial ocular surface microbiome in clinically normal cats before and after treatment with topical erythromycin. PLoS One 2019; 14:e0223859. [PMID: 31603921 PMCID: PMC6788832 DOI: 10.1371/journal.pone.0223859] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 09/30/2019] [Indexed: 02/01/2023] Open
Abstract
The ocular surface microbiome of veterinary species has not been thoroughly characterized using next generation sequencing. Furthermore, alterations in the feline ocular surface microbiome over time or following topical antibiotic treatment are unknown. Aims of this study were to further characterize the ocular surface microbiome of healthy cats and to identify whether there are microbial community changes over time and following topical antibiotic use. Twenty-four eyes from twelve adult, research-bred, female spayed domestic shorthaired cats were evaluated. Erythromycin ophthalmic ointment (0.5%) was applied to the ocular surface of one randomly assigned eye per cat three times daily for 7 days, while the fellow eye served as an untreated control. The ocular surface was sampled by swabbing the inferior conjunctival fornix of both eyes prior to initiating treatment (day 0), after 1 week of treatment (day 7), and 4 weeks after concluding treatment (day 35). Genomic DNA was extracted from the swabs and sequenced using primers that target the V4 region of bacterial 16S rRNA genes. At baseline, the most common bacterial phyla identified were Proteobacteria (42.4%), Firmicutes (30.0%), Actinobacteria (15.6%), and Bacteroidetes (8.1%). The most abundant bacterial families sequenced were Corynebacteriaceae (7.8%), Helicobacteraceae (7.5%), Moraxellaceae (6.1%), and Comamonadaceae (5.6%). Alpha and beta diversity measurements were largely unchanged in both treatment and control eyes over time. However, univariate and linear discriminant analyses revealed significant and similar changes in the abundance of some bacterial taxa over time in both treatment and control eyes. Overall, the feline ocular surface microbiome remained stable over time and following topical antibiotic therapy.
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Affiliation(s)
- Joshua E. Darden
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Erin M. Scott
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
| | - Carolyn Arnold
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Elizabeth M. Scallan
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Bradley T. Simon
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Jan S. Suchodolski
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
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Ozkan J, Willcox M, Wemheuer B, Wilcsek G, Coroneo M, Thomas T. Biogeography of the human ocular microbiota. Ocul Surf 2019; 17:111-118. [DOI: 10.1016/j.jtos.2018.11.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/22/2018] [Accepted: 11/09/2018] [Indexed: 12/20/2022]
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