Molecular evidence for multiple host-specific strains in the genus Rhinosporidium

Rhinosporidiosis-Factors predicting disease recurrence

BACKGROUND

Rhinosporidiosis is a chronic granulomatous disease of the nose caused by Rhinosporidium seeberi. The disease is largely non-amenable to medical therapy and shows high recurrence rates requiring patients to undergo multiple surgeries often resulting in increased morbidity.

OBJECTIVE

To analyse the epidemiological, clinical, histopathological characteristics, treatment and outcome in rhinosporidiosis and to identify factors which predispose to recurrence of the disease.

PATIENTS/METHODS

Retrospective analysis of data of all patients with a diagnosis of rhinosporidiosis confirmed by histopathology at a tertiary care hospital from 2015 to 2019.

RESULTS

There were 42 patients, 40 males and two females, with a mean age of 37.37 years. Disease showed bilateral involvement in 17 (40.48%) patients. Nineteen (45.24%) patients had more than two sites involved at initial presentation. Most patients had nasal cavity involvement followed by nasopharynx. Among the 28 patients who had a follow-up, 12 showed recurrent disease. However, 21 patients were disease free following a revision excision. Involvement of more than two sites was an independent significant factor for recurrence. On univariate analysis, other factors which showed statistically significant odds of developing recurrence were previous surgery (p = .054), involvement of nasal septum (p = .022), middle turbinate (p = .024), nasopharynx (p = .049) and posterior pharyngeal wall (p = .05). Factors which showed significantly less likelihood of developing a recurrence included patients who had less than 12 months duration from first symptom to intervention (p = .016), involvement of less than two sites (p = .0003) and unilateral disease (p = .019).

CONCLUSION

Early intervention in rhinosporidiosis especially when the disease is unilateral and involves less than two sites improves the outcome.

Lacrimal sac rhinosporidiosis

Rhinosporidiosis is a chronic mucocutaneous granulomatous disease caused by Rhinosporidium seeberi, involving primarily the nose and nasopharynx. Very rarely, the disease can affect the lacrimal sac. Here we report a 35-year-old male patient who had rhinosporidial involvement of the nose 5 years ago, for which he underwent endoscopic nasal surgery. Five years after the excision of the nasal mass, he presented with lacrimal sac involvement. The clinical presentation and the management of lacrimal sac rhinosporidiosis are discussed here.

Rhinosporidiosis in the Americas: A Systematic Review of Native Cases

Rhinosporidiosis is a chronic mucosal infection caused by Rhinosporidium seeberi, an aquatic protistan parasite. It presents as nasal or ocular polypoidal or vascularized masses. It is endemic in tropical and subtropical areas, especially in South Asia; R. seeberi´s endemicity in the Americas is often overlooked. The objective of this study was to describe the demographic and clinical characteristics of patients with rhinosporidiosis in the Americas, its management, and patient outcomes. This study is a systematic review of cases of human rhinosporidiosis in the Americas reported in the literature from 1896 to February 28, 2019. This review screened 1,994 reports, of which 115 were eligible for further analysis. The selected reports described 286 cases of human rhinosporidiosis between 1896 and 2019. Cases were diagnosed in Brazil (32.2%), Colombia (24.4%), Paraguay (12.6%), and the United States (11.9%). The majority of the cases (91%) occurred in geographic areas with altitudes < 1,000 m above sea level and in areas with median temperatures ≥ 25°C (67.3%). Most of the patients presented nasal (65%) and ocular involvement (35%). Surgical treatment was provided for 99.6% of patients, but 19.8% of them recurred. This review describes the under-recognized geographic distribution and clinical presentation of rhinosporidiosis in the Americas and highlights clinical differences to cases in Asia, specifically in reference to a higher prevalence of ocular disease and higher relapse rates.

Tracheobronchial rhinosporidiosis: an uncommon life-threatening benign cause of airway obstruction

Rhinosporidiosis is a chronic granulomatous infectious disease caused by Mesomycetozoea Rhinosporidium seeberi. This highly recurrent polypoid lesion has a predilection for the nose and nasopharynx, although other organ systems may be affected. Involvement of the tracheobronchial tree is very rare, and poses a challenge for diagnosis and management. In this report, we present a 30-year-old man with a history of recurrent nasal polyp who presented with cough, shortness of breath, haemoptysis, and a radiological feature of right lung collapse on imaging. He was diagnosed with rhinosporidiosis based on histopathological examination of bronchoscopic biopsy specimen taken from the right principal bronchial mass. Shortly after hospitalization, he developed acute respiratory distress requiring emergency bronchoscopic intervention. A pinkish mulberry-like tracheal and right bronchial mass was removed endoscopically with cauterization of the base of the lesion. On long-term follow-up, the patient was free of symptoms without recurrence of airway disease.

Long-term use of Le Fort I osteotomy for the management of nasopharyngeal rhinosporidiosis: A case series

Rhinosporidiosis is a rare, chronic, granulomatous infection of the mucous membranes that mainly involves the nose and nasopharynx; it occasionally involves the pharynx, conjunctiva, larynx, trachea and, rarely, the skin. The characteristic clinical features of this disease include the formation of painless polyps in the nasal mucosa or the nasopharynx that bleed easily on touch. At our center, excision of the lesion with a Le Fort I osteotomy is carried out in patients (1) in whom two or more previous attempts at excision of biopsy-proven rhinosporidiosis arising from the nasal mucosa was carried out or (2) in whom the rhinosporidiosis arises from the nasophayrngeal mucosa and/or extranasal sites. In this article we retrospectively present 7 cases in which, according to our inclusion criteria, complete excision of the lesion was carried out with a Le Fort I osteotomy. Excellent visualization of the entire maxillary and ethmoidal air cells after the down-fracture of the maxilla helped in the total removal of the lesions. Most of these lesions had multiple points of origin through the nasal, maxillary, and ethmoidal mucosa; the excellent visualization enabled direct cauterization of all these points of origin. The mean follow-up period was 7.96 years, and all patients were disease-free by the time the study was prepared. This article presents details of the treatment protocol and technique followed at our center for the treatment of nasopharyngeal rhinosporidiosis and the details of long-term follow-up. Through this study we hope to prove the efficacy of Le Fort I osteotomy in the definitive management of nasopharyngeal rhinosporidiosis.

Nasopharyngeal rhinosporidiosis with intracranial extension masquerading as juvenile angiofibroma: an unusual entity

Rhinosporidiosis is a chronic fungal inflammatory disease prevalent in India and Sri Lanka. Its manifestations are mostly nasal and extranasal lesions are relatively rare. Occasional atypical presentations of this disease lead to diagnostic dilemma. Herein we report on a case of nasopharyngeal rhinosporidiosis having extensive involvement of paranasal sinuses along with intracranial extension which mimicked radiologically as juvenile nasopharyngeal angiofibroma. To our knowledge, this is the first reported case of rhinosporidiosis having intracranial extension. We discuss the pathology, treatment and briefly review the literature of this rare disease.

A review of the pathology and treatment of canine respiratory infections

Numerous infectious agents are responsible for causing primary or secondary respiratory disease in dogs. These agents can cause upper or lower respiratory infections commonly observed in veterinary practices. Clinical signs might vary from mild dyspnea, sneezing, and coughing to severe pneumonia with systemic manifestations. Depending on the etiologic agent, the gross and microscopic changes observed during these infections can be rather unspecific or have highly characteristic patterns. While histopathology and cytology are not always required for diagnosis of respiratory infections, they are often useful for establishing a definitive diagnosis and identifying specific etiologic agents. Research regarding epidemiology, pathogenesis, diagnostics, and clinical manifestations related to these infectious pathogens provides valuable information that has improved treatments and management of the diseases they cause. This review discusses the epidemiology, general clinical characteristics, and pathologic lesions for some of the important viral, bacterial, fungal, and parasitic etiologies of canine respiratory disease.

Introduced pathogens and native freshwater biodiversity: a case study of Sphaerothecum destruens

A recent threat to European fish diversity was attributed to the association between an intracellular parasite, Sphaerothecum destruens, and a healthy freshwater fish carrier, the invasive Pseudorasbora parva originating from China. The pathogen was found to be responsible for the decline and local extinction of the European endangered cyprinid Leucaspius delineatus and high mortalities in stocks of Chinook and Atlantic salmon in the USA. Here, we show that the emerging S. destruens is also a threat to a wider range of freshwater fish than originally suspected such as bream, common carp, and roach. This is a true generalist as an analysis of susceptible hosts shows that S. destruens is not limited to a phylogenetically narrow host spectrum. This disease agent is a threat to fish biodiversity as it can amplify within multiple hosts and cause high mortalities.

The regional sero-epidemiology of rhinosporidiosis in Sri Lankan humans and animals

No data is available in the world literature on serum anti-rhinosporidial antibody levels in animals, and as far as we aware this is the first report. Although rhinosporidiosis in farm and domestic animals has been widely reported from other countries, rhinosporidiosis in animals has not been reported in Sri Lanka, though this country has the highest world-wide prevalence of human rhinosporidiosis on a unit-population basis. Serum IgG titres in 6 species of Sri Lankan animals (buffalo, cat, cattle, dog, goat, horse; total 291) were assayed by the Immuno blot (dot-ELISA) method on nitrocellulose paper and were compared with serum IgG titres in normal Sri Lankan human subjects (total 211) in different geographical areas, and in human Sri Lankan patients with rhinosporidiosis as reference values (total 36). Sensitization to rhinosporidial antigen(s) was detected in all 6 species of animals and the highest titres (1/3200) were found in cats, and free-grazing horses. Cattle showed higher levels of antibody than buffaloes. The titres in these animals are compared with world reports on overt rhinosporidiosis in these species, and with titres in normal Sri Lankan humans. Human, but not animal titres showed variations compatible with the regional prevalence of rhinosporidiosis. The variations in titres in animals especially horses, were probably more related to their mode of feeding, while in humans the titres in normal persons were probably related to the rhinosporidial-endemicity of their respective regions. No conclusions from sero-positivity in animals could be made regarding the absence of reports on rhinosporidiosis as an overt disease in these Sri Lankan animal species but the possibility of a genetically-determined insusceptibility to rhinosporidiosis in Sri Lanka, is considered. Rhinosporidium seeberi-specific PCR positive reactions were obtained with nasal scrapings from cattle that microscopically showed PAS+ bodies that were compatible with rhinosporidial sporangia. Sequence-analysis of the reactions products from five positive R. seeberi-specific PCR samples (four in this study and 1 in a previous study) gave results confirmatory of R. seeberi.

[A new case of rhinosporidiosis in Chile]

BACKGROUND

Rhinosporidiosis is a chronic, granulomatous, and non-contagious infection, in which highly vascularized polyps (mainly present in the nasal cavity) appear. These polyps usually bleed easily.

AIMS

To present the case of a 14 year-old male suffering from an obstruction and injury of the right nostril due to a polypoid shaped-lesion with a raspberry-like appearance.

METHODS

A wide surgery resection of the base of the lesion was performed, as well as a standard histopathology procedure, including microscopic analysis with haematoxylin-eosin and Grocott staining.

RESULTS AND CONCLUSIONS

The histopathology report indicated that the chronic inflammatory polyp was compatible with rhinosporidiosis.

Nasal rhinosporidiosis in humans: new interpretations and a review of the literature of this enigmatic disease

Rhinosporidiosis is a disease caused by Rhinosporidium seeberi which primarily affects the mucosa of the nose, conjunctiva and urethra. While it is endemic in some Asian regions, isolated cases are reported in other parts of the world as a result of the socio-cultural phenomenon of the migration. Its manifestation is a polypoid mass growing inside the affected cavity and the only treatment is surgical excision. Rhinosporidiosis is a condition which both clinicians and microbiologists should keep in mind when managing patients with nasal masses even those from non endemic areas. It is critical in such cases to follow the clinical course to ensure against recurrence of the disease. This study describes the clinical features, diagnosis, and treatment of rhinosporidiosis of the nose and nasopharynx in a series of three cases in East Delhi, India.

Nasal rhinosporidiosis in two dogs native to the upper Mississippi river valley region

Two dogs, 4 and 7 years of age, were presented for evaluation and treatment of excessive sneezing. Physical examinations in both cases were within acceptable limits except for the presence of a single mass in the left nasal passage in the first case and left-sided nasal discharge in the second case. Rhinoscopy was used to visualize the nasal masses, and in both cases a single mass was surgically removed. Impression smears and histopathology submitted from each mass revealed lymphoplasmacytic and neutrophilic inflammation with spores typical of Rhinosporidium seeberi. These are the first reported cases of nasal rhinosporidiosis in two dogs native to the Upper Mississippi River Valley area with no travel history outside the region.

Multiple isolations of a culturable, motile Ichthyosporean (Mesomycetozoa, Opisthokonta), Creolimax fragrantissima n. gen., n. sp., from marine invertebrate digestive tracts

A fragrant, spherical, osmotrophic eukaryote was isolated 27 times from the digestive tracts of marine invertebrates collected from the Northeast Pacific. The isolates were cultured from 7 animal collections over a 2-year period, most from the peanut worm, Phascolosoma agassizii. A small subunit ribosomal DNA phylogeny placed the spherical organism within the ichthyosporea, closest to Sphaeroforma arctica and Pseudoperkinsus tapetis. Supporting the close relationship of isolates, the sequences of ribosomal gene internal transcribed spacers determined for 26 isolates were identical, as were the elongation factor 1-alpha-like gene fragments from 7 isolates. Dispersal via amoeboid cells distinguished this species from its closest relatives and led to the erection of a new genus and species, "Creolimax fragrantissima." Vegetative cells reproduced asexually in vitro after they reached 30-60 microm in diameter by producing amoebae or endospores, which escaped through openings in the parent cell wall. Ultrathin sections of vegetative cells prepared by high-pressure-freeze substitution provided some of the first images of ichthyosporean spindle pole bodies and document, for the first time, tubular extensions of the plasma membrane into an electron-translucent inner layer of the cell wall. Ichthyosporeans are parasites and commensals of animals and culturable species are few. Because "C. fragrantissima" can be isolated regularly and repeatedly from nature and then grown easily through cycles of asexual reproduction, it has the potential to serve as a model organism for further research into marine ichthyosporeans.

Equine rhinosporidiosis in United Kingdom

We report 4 cases of equine rhinosporidiosis in the United Kingdom. These cases provide evidence of spread of infectious agents from rhinosporidiosis-endemic areas to nonendemic areas by increased international movement of livestock. Surveillance should continue for this infective agent of potential relevance for numerous species, including humans.

Molecular identification of the ichthyosporean protist "Pseudoperkinsus tapetis" from the mytilid mussel Adipicola pacifica associated with submerged whale carcasses in Japan

A protist tentatively designated "Pseudoperkinsus tapetis" belonging to the eukaryotic group Ichthyosporea (Mesomycetozoa) was previously isolated from carpet shell clams in Galicia (northwest Spain). In the present study, based on molecular data, a potential P. tapetis specimen was identified from the gill tissues of the mussel Adipicola pacifica associated with whale carcasses (generating chemosynthetic-based ecosystems) collected at shelf depths in the northwest Pacific (southwest Japan). Small subunit ribosomal DNA sequences (1751 sites) of the genotypes of P. tapetis from Spain and Japan were almost identical (only one substitution and one insertion/deletion difference). On the other hand, differences of 10 and 8 substitutions were found in two internal transcribed spacer regions of ribosomal DNA, ITS1 (288 sites) and ITS2 (251 sites) between these two genotypes, respectively, indicating that they are genetically different at the population level. These findings suggest that P. tapetis occurs worldwide and can associate with (and possibly infect) various types of bivalves. Further, a PCR method to specifically detect the P. tapetis cells in the host was also established.

Outbreaks of phaeohyphomycosis in the chinook salmon (Oncorhynchus tshawytscha) caused by Phoma herbarum

Phoma herbarum has been associated with two outbreaks of systemic mycosis in hatchery-reared chinook salmon (Oncorhynchus tshawytscha) fingerlings. Affected fish exhibited abnormal swimming behavior, exophthalmia, multiple rounded areas of muscle softening, protruded hemorrhagic vents, and abdominal swelling. In all affected fish, swimbladders were filled with whitish creamy viscous fungal mass, surrounded by dark red areas in swimbladder walls, kidneys, and musculature. Clinical and histopathological examinations suggest that the infection may have started primarily in the swimbladder and then spread to the kidneys, gastrointestinal tract, and surrounding musculature. Consistent microscopical findings included broad septate branched fungal hyaline hyphae, 5-12 microm in diameter within the swimbladder, stomach, and often within and adjacent to blood vessels. Profuse growths of woolly brown fungal colonies were obtained from swimbladders and kidneys on Sabouraud medium. On corn meal agar the formation of pycnidia, characteristic of Phoma spp., was detected within 10 days of incubation. Morphological and molecular analyses identified this fungus as Phoma herbarum. This report underscores systemic fungal infections as a threat to raceway-raised salmon.

Nasal rhinosporidiosis in a mule

A mass was removed from the nostril of a mule that exhibited unilateral epistaxis and nasal discharge. Impression smears revealed oval structures consistent with spores of Rhinosporidium seeberi. Microscopically, the mass was composed of fibrovascular granulomatous tissue containing sporangia R. seeberi. Surgical excision and antifungal treatment proved curative.

Nosocomial candiduria in women undergoing urinary catheterization. Clonal relationship betweenstrains isolated from vaginal tract and urine

We determined the incidence of nosocomial candiduria associated with indwelling urinary catheters in 42 women with and without Candida spp. vaginal colonization being treated in the intensive care unit (ICU). We established a relationship between strains initially isolated from the vaginal tract and those subsequently recovered from urine samples through the use of random amplified polymorphic DNA (RAPD). The overall incidence of nosocomial candiduria in these patients was 21.4%. Vaginal colonization by Candida spp. was detected in 11 patients (26.2%) of whom 6 (54.5%) developed candiduria. In comparison, only 3 (9.7%) cases of candiduria were found in women who were not colonized by the yeast (RR: 4.4, 95% CI 1.61-86.8, P=0.005). The dendrogram obtained by RAPD using 14 primers showed that the strains isolated from vagina and urine samples in five women had high similarity values (SAB >0.9) forming independent clusters. Our study suggests that women vaginally colonized by Candida spp. in an ICU setting have a high risk of acquiring nosocomial candiduria and that strains isolated from both sites in a single patient may be genetically related.

Lacazia loboi and Rhinosporidium seeberi: a genomic perspective

In the past five years, with the use of molecular strategies the phylogenetic affinities of the two more resilient pathogens studied in medical mycology, Lacazia loboi and Rhinosporidium seeberi were finally deciphered. These studies found that L. loboi was the sister taxon to Paraccidioides brasiliensis, and R. seeberi was closely related to protistan spherical aquatic fish pathogens, located at the point were animals diverged from the fungi, in the class Mesomycetozoea. These initial studies indicated that a molecular strategy was the ideal approach to further understand these anomalous pathogens. However, the limited amount of information gathered so far from few DNA sequences, although crucial to place these organisms in the tree of life and to take a glance to their ecological preferences, did not provide answers to other important traits. In the following pages we discuss a genomic perspective for both pathogens and the benefit that such information could generate to understand more about these two uncultivated pathogens.