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Ueno S, Eguchi H, Hotta F, Fukuda M, Kimura M, Yagita K, Suzuki T, Kusaka S. Microsporidial keratitis retrospectively diagnosed by ultrastructural study of formalin-fixed paraffin-embedded corneal tissue: a case report. Ann Clin Microbiol Antimicrob 2019; 18:17. [PMID: 31182106 PMCID: PMC6558824 DOI: 10.1186/s12941-019-0316-y] [Citation(s) in RCA: 4] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 06/06/2019] [Indexed: 01/07/2023] Open
Abstract
Background The utility of formalin-fixed paraffin-embedded (FFPE) corneal tissue specimens for retrospective diagnosis of microsporidial keratitis was evaluated by transmission electron microscopy (TEM) analysis and the possible second case of microsporidial keratitis after Descemet stripping automated endothelial keratoplasty (DSAEK) was described. Case presentation A 68-year-old man presented with multiple crystalline opacities in the corneal stroma that progressed extremely slowly after DSAEK. Fungiflora Y staining of corneal scrapings from the affected regions revealed an oval microorganism. Topical voriconazole administration was ineffective and penetrating keratoplasty was performed. Histological and molecular analyses were carried out on the excised cornea. Ziehl–Neelsen staining revealed an acid-fast, oval organism that was visible by ultraviolet illumination after Fungiflora Y and Uvitex 2B staining, whereas periodic acid-Schiff and Grocott’s staining did not yield any significant findings. Microsporidium was detected by TEM of FFPE tissue. Nosema or Vittaforma sp. was suspected as the causative microorganism by PCR of FFPE tissue and by the fact that those species are known to cause eye infection. The corneal graft has maintained transparency at 1 year and half postoperatively. Conclusions This is the first known case of microsporidial keratitis diagnosed retrospectively by molecular and ultrastructural study of FFPE tissue, and the possible second case of microsporidial keratitis after DSAEK. Microsporidial keratitis should be considered when corneal opacity refractory to conventionally known therapy would occur after DSAEK. Our findings suggest that more microsporidial keratitis cases than have been reported to date can be identified by TEM or PCR examination of FFPE corneal specimens.
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Affiliation(s)
- Satoru Ueno
- Department of Ophthalmology, Kindai University Faculty of Medicine, 377-2, Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan
| | - Hiroshi Eguchi
- Department of Ophthalmology, Kindai University Faculty of Medicine, 377-2, Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan.
| | - Fumika Hotta
- Department of Ophthalmology, Kindai University Faculty of Medicine, 377-2, Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan
| | - Masahiko Fukuda
- Department of Ophthalmology, Kindai University Faculty of Medicine, 377-2, Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan
| | - Masatomo Kimura
- Department of Pathology, Kindai University Faculty of Medicine, 377-2, Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan
| | - Kenji Yagita
- Department of Parasitology, National Institute of Infectious Diseases, 1-23-1, Toyama, Shinjuku, Tokyo, 162-8640, Japan
| | - Takashi Suzuki
- Department of Ophthalmology, Toho University Medical Center, 6-11-1, Ohmorinishi, Ota, Tokyo, 143-8541, Japan
| | - Shunji Kusaka
- Department of Ophthalmology, Kindai University Faculty of Medicine, 377-2, Ohnohigashi, Osakasayama, Osaka, 589-8511, Japan
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Chen JS, Hsu TK, Hsu BM, Huang TY, Huang YL, Shaio MF, Ji DD. Surveillance of Vittaforma corneae in hot springs by a small-volume procedure. Water Res 2017; 118:208-216. [PMID: 28432932 DOI: 10.1016/j.watres.2017.04.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/21/2017] [Accepted: 04/09/2017] [Indexed: 06/07/2023]
Abstract
Vittaforma corneae is an obligate intracellular fungus and can cause human ocular microsporidiosis. Although accumulating reports of V. corneae causing keratoconjunctivitis in both healthy and immunocompromised persons have been published, little is known about the organism's occurrence in aquatic environments. Limitations in detection sensitivity have meant a large sampling volume is required to detect the pathogen up to now, which is problematic. A recent study in Taiwan has shown that some individuals suffering from microsporidial keratitis (MK) were infected after exposure to the pathogen at a hot spring. As a consequence of this, a survey and analysis of environmental V. corneae present in hot springs became an urgent need. In this study, sixty water samples from six hot spring recreation areas around Taiwan were analyzed. One liter of water from each sample site was filtered to harvest the fungi. The positive samples were detected using a modified nested PCR approach followed by sequencing using specific SSU rRNA gene primer pairs for V. corneae. In total fifteen V. corneae-like isolates were identified (25.0% of sites). Among them, six isolates, which were collected from recreational areas B, C and D, were highly similar to known V. corneae keratitis strains from Taiwan and other countries. Furthermore, five isolates, which were collected from recreation areas A, C, E and F, were very similar to Vittaforma-like diarrhea strains isolated in Portugal. Cold spring water tubs and public foot bath pools had the highest detection rate (50%), suggesting that hot springs might be contaminated via untreated water sources. Comparing the detection rate across different regions of Taiwan, Taitung, which is in the east of the island, gave the highest positive rate (37.5%). Statistical analysis showed that outdoor/soil exposure and a high heterotrophic plate count (HPC) were risk factors for the occurrence of V. corneae. Our findings provide empirical evidence supporting the need for proper control and regulations at hot spring recreational waters in order to avoid health risks from this pathogen. Finally, we have developed a small volume procedure for detecting V. corneae in water samples and this has proved to be very useful.
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Affiliation(s)
- Jung-Sheng Chen
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Tsui-Kang Hsu
- Department of Ophthalmology, Cheng Hsin General Hospital, Taipei, Taiwan, ROC
| | - Bing-Mu Hsu
- Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Minhsiung Township, Chiayi County, 62102, Taiwan, ROC.
| | - Tung-Yi Huang
- Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Minhsiung Township, Chiayi County, 62102, Taiwan, ROC
| | - Yu-Li Huang
- Department of Safety Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan, ROC
| | - Men-Fang Shaio
- Department of Tropical Medicine, National Yang-Ming University, No.155, Sec.2, Li-Nong Street, Taipei, 112, Taiwan, ROC
| | - Dar-Der Ji
- Department of Tropical Medicine, National Yang-Ming University, No.155, Sec.2, Li-Nong Street, Taipei, 112, Taiwan, ROC.
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