Ocular Microsporidiosis

Sharma, Savitri; Balne, Praveen Kumar; Das, Sujata

doi:10.1002/9781118395264.ch16

Cited by 5 publications

(8 citation statements)

References 108 publications

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“…41 The acid-fast microsporidian spores appear as round clumped structures with a dark band at the tip. 47 Unfortunately, this stain was impractical for detecting E. cuniculi spores in our study, possibly because the spores have limited lipid content. 23 We have proposed 3 stain categories based on their affinity and sensitivity in detection of E. cuniculi spores.…”

Section: Discussionmentioning

confidence: 86%

“…51,59 Most of the histochemical information in the literature comes from ophthalmologic biopsies or conjunctival smears, without confirmatory detection, using different stains and then extrapolating that information to other microsporidia. 47 We are not aware of any previous literature pertaining to histochemical studies of rabbits infected with E. cuniculi. In our study, renal tissue was selected because E. cuniculi spore-laden cysts are defined more frequently in this organ than in any other tissue.…”

Section: Discussionmentioning

confidence: 99%

“…Significant improvement has been made in the development of complementary staining methods for the detection of microsporidians. In the literature, the majority of the staining techniques are performed on cytologic and wet preparations, 47 and results are presented as general tables, without specifying genera of microsporidia. The stains that are used in these preparations may not give the same results in histologic samples because of the tissue features and the different procedures used for tissue processing.…”

Section: Research-article2017mentioning

confidence: 99%

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Histochemical study of Encephalitozoon cuniculi spores in the kidneys of naturally infected New Zealand rabbits

et al. 2017

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Encephalitozoon cuniculi is an important microsporidian pathogen that is considered an emergent, zoonotic, and opportunistic. It infects both domestic and laboratory rabbits, generating severe chronic interstitial and granulomatous nephritis with fibrosis and granulomatous encephalitis. Encephalitozoonosis is diagnosed in paraffin-embedded sections by examining the spores in the host tissues. The spores are difficult to observe when the samples are stained with hematoxylin and eosin (H&E), particularly when there is an inflammatory reaction and tissue damage. The spores are easily mistaken for other microorganisms, such as fungi (yeasts), protozoa, and bacteria. In our study, we used kidney samples from E. cuniculi-positive rabbits and employed 14 recommended histologic stains for detecting microsporidia spores: alcian blue, calcofluor white, Giemsa, Gram, Grocott, H&E, Luna, Luxol fast blue, Masson trichrome, modified trichrome stain (MTS), periodic acid-Schiff reaction (PAS), Van Gieson, Warthin-Starry (WS), and Ziehl-Neelsen (ZN).We concluded that MTS and Gram stain, detected by light microscopy, and calcofluor white stain, detected by ultraviolet light microscopy, are the best stains for detecting spores of E. cuniculi in paraffin-embedded tissues from infected rabbits. These stains were superior to WS, ZN, Giemsa, and PAS for identifying spores without background "noise" or monochromatic interference. Also, they allow individual spores to be discerned in paraffin-embedded tissues. MTS allows observation of the polar tube, polaroplast, and posterior vacuole, the most distinctive parts of the spore.

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Section: Discussionmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Section: Research-article2017mentioning

confidence: 99%

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Histochemical study of Encephalitozoon cuniculi spores in the kidneys of naturally infected New Zealand rabbits

et al. 2017

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“…Moreover, this group includes 17 species causing human disease; the most common belong to the genera Enterocytozoon and Encephalitozoon (Fayer & Santin‐Duran, 2014; Franzen & Müller, 2001; Stentiford et al., 2016). In immunosuppressed hosts, including humans, Microsporidia can infect any organ system; the most widely reported infections concern encephalitis, myositis, ocular infection and sinusitis (Sharma, Balne, & Das, 2014; Wang et al., 2018; Weiss, 2014; Weiss & Schwartz, 2015).…”

Section: Introductionmentioning

confidence: 99%

A new method of metabarcoding Microsporidia and their hosts reveals high levels of microsporidian infections in mosquitoes (Culicidae)

Trzebny

Słodkowicz-Kowalska

Becnel

et al. 2020

Molecular Ecology Resources

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DNA metabarcoding offers new perspectives, especially with regard to the highthroughput identification and diagnostics of pathogens. Microsporidia are an example of widely distributed, opportunistic and pathogenic microorganisms in which molecular identification is important for both environmental research and clinical diagnostics. We have developed a method for parallel detection of both microsporidian infection and the host species. We designed new primer sets: one specific for the classical Microsporidia (targeting the hypervariable V5 region of small subunit [ssu] rDNA), and a second one targeting a shortened fragment of the COI gene (standard metazoan DNA-barcode); both markers are well suited for next generation sequencing. Analysis of the ssu rDNA data set representing 607 microsporidian species (120 genera) indicated that the V5 region enables identification of >98% species in the data set (596/607). To test the method, we used microsporidians that infect mosquitoes in natural populations. Using mini-COI data, all field-collected mosquitoes were unambiguously assigned to seven species; among them almost 60% of specimens were positive for at least 11 different microsporidian species, including a new microsporidian ssu rDNA sequence (Microsporidium sp. PL01). Phylogenetic analysis showed that this species belongs to one of the two main clades in the Terresporidia. We found a high rate of microsporidian co-infections (9.4%). The numbers of sequence reads for the operational taxonomic units suggest that the occurrence of Nosema spp. in co-infections could benefit them; however, this observation should be retested using a more intensive host sampling. Our results show that DNA barcoding is a rapid and cost-effective method for deciphering sample diversity in greater resolution, including the hidden biodiversity that may be overlooked using classical methodology.

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“…21 In Asia, the prevalence of microsporidial keratoconjunctivitis varies between 0.4% and 19.7%, 23,25 whereas the prevalence of stromal keratitis is lower. 26 To date, 56 cases of Vittaforma corneae corneal lesions were reported in the Southeast Asia (Table 1). [27][28][29][30] The sources and routes of ocular infection are less clear than those for digestive diseases.…”

Section: Discussionmentioning

confidence: 99%

Case Report: Ocular Microsporidiosis: Case in a Patient Returning from India and Review of the Literature

Leroy

Cornu

Deleplancque³

et al. 2018

The American Journal of Tropical Medicine and Hygiene

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Microsporidia are protists close to the kingdom of fungi that may cause eye infections. Most cases are reported in Asia and affect both immunocompromised and immunocompetent patients. Here, we report a rare case of microsporidial keratoconjunctivitis in an immunocompetent French patient 3 weeks after returning from India. In our patient, Weber trichrome staining of conjunctival scrapings revealed rounded elements approximately 1-3 μm in size. Conventional polymerase chain reaction analysis by ribosomal RNA subunit sequencing showed 100% identity with . Treatment by corneal debridement combined with fluoroquinolone eye drops allowed complete resolution of the lesions. Although rare, ocular microsporidiosis should be investigated in a patient who is native to Asia or has returned from an endemic area and presents with keratoconjunctivitis of undetermined etiology.

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Ocular Microsporidiosis

Cited by 5 publications

References 108 publications

Histochemical study of Encephalitozoon cuniculi spores in the kidneys of naturally infected New Zealand rabbits

Histochemical study of Encephalitozoon cuniculi spores in the kidneys of naturally infected New Zealand rabbits

A new method of metabarcoding Microsporidia and their hosts reveals high levels of microsporidian infections in mosquitoes (Culicidae)

Case Report: Ocular Microsporidiosis: Case in a Patient Returning from India and Review of the Literature

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