Basidiobolomycosis: an unusual, mysterious, and emerging endemic fungal infection

SCHIZANGIELLA INFECTIONS IN AN EASTERN RATSNAKE (PANTHEROPHIS ALLEGHANIENSIS) AND A TIMBER RATTLESNAKE (CROTALUS HORRIDUS)

This report describes Schizangiella infections in colubrid and viperid snakes. A captive eastern ratsnake (Pantherophis alleghaniensis) was presented for a large intraoral mass associated with the mandible. The mass was debulked and histologic examination revealed severe, granulomatous stomatitis with intralesional fungi exhibiting morphologic features consistent with Schizangiella serpentis. PCR and sequencing of affected tissues confirmed S. serpentis. Because of declining health, the ratsnake was euthanized and postmortem examination identified a disseminated S. serpentis infection involving the skeletal musculature, lung, kidney, mesentery, and mandible. A wild-caught timber rattlesnake (Crotalus horridus) was presented for cutaneous lesions, weakness, and lethargy and later died. Postmortem examination revealed a mass-like structure in the esophagus characterized by high numbers of Schizangiella-like fungi associated with extensive granulomatous inflammation; the snake also had cutaneous mycosis suggestive of ophidiomycosis. This is the first report to document the unique morphologic features of S. serpentis in tissues and the presentation of schizangiellosis in snakes. Schizangiellosis should be considered as a differential diagnosis for nodular lesions involving the oral cavity and/or the gastrointestinal tract of snakes.

Differentiation of Basidiobolus spp. Isolates: RFLP of a Diagnostic PCR Amplicon Matches Sequence-Based Classification and Growth Temperature Preferences

The genus Basidiobolus, known since 1886, is primarily associated with reptiles and amphibians. Although globally distributed, rare infections caused by members of this genus mainly occur in tropical and subtropical regions. Morphological and physiological characteristics were used in the past for the description of species. However, some of these characteristics vary depending on culture conditions. Therefore, most species names are regarded as synonyms of B. ranarum as the only pathogenic species. Yet, not all environmental isolates are necessarily pathogenic. This study aimed to analyze if environmental Basidiobolus isolates can be distinguished reliably based on morpho-physiological and molecular characteristics. Eleven isolates originally obtained from feces of south African reptiles and one type strain, Basidiobolus microsporus DSM 3120, were examined morpho-physiologically. Sequence analysis of the 18S and partial 28S rRNA gene and restriction analysis of a diagnostic amplicon (restriction fragment length polymorphism, RFLP) were performed for all 12 strains. Based on the results obtained, morphological features and the 18S rRNA sequence proved insufficient for the reliable differentiation of isolates. However, isolates were distinguishable by growth temperature profiles, which matched isolate clusters established by partial 28S rRNA gene sequence and restriction analysis of a Basidiobolus specific diagnostic PCR amplicon. Our results indicate that RFLP analysis can be used as a fast screening method to identify Basidiobolus isolates with similar physiological characteristics.

Gastrointestinal basidiobolomycosis: An emerging mycosis difficult to diagnose but curable. Case report and review of the literature

BACKGROUND

Gastrointestinal basidiobolomycosis (GIB) is a rare mycosis affecting almost exclusively immunocompetent subjects.

METHODS

We describe a case of GIB caused by Basidiobolus ranarum in a 25-year-old Italian immunocompetent man resident in Ireland who presented a 2-month history of epigastric pain. Suspecting colon cancer he underwent a right hemicolectomy subsequently leading to a diagnosis of GIB by means of molecular biology. After surgery a 9-month therapy with itraconazole was employed with a good outcome. A review of medical literature regarding GIB cases published in the period 1964-2017 is presented.

RESULTS

One-hundred and two cases of GIB were included in this analysis. The disease was observed predominantly in male gender (74.5%) and children (41.2%). Abdominal pain was the single most common complaint (86.3%) followed by fever (40.2%) and evidence of an abdominal mass (30.4%). Peripheral blood eosinophilia was detected in 85.7% of cases. Most of the patients were diagnosed in Saudi Arabia (37.2%) followed by USA (21.6%) and Iran (20.6%). Surgery plus antifungal therapy was employed in the majority of patients (77.5%). An unfavourable outcome was documented globally in 18.6% of patients.

CONCLUSIONS

GIB seems to be an emerging intestinal mycosis among immunocompetent patients living in the Middle East and Arizona.

First-time isolation and quantification of Basidiobolus spp. from reptile faeces in KwaZulu-Natal (South Africa) using selective media

Members of the genus Basidiobolus are potentially pathogenic fungi, known to cause mycoses in tropical and subtropical countries. Basidiobolus spp. can be associated with animals, and reptiles and amphibians are candidate vectors for the distribution of this fungus. The presence of Basidiobolus spp. was described for different reptiles in several African countries, although not for South Africa. In addition, quantitative data are scarce. The aim of this study was to analyse faeces of selected South African reptiles for the presence and quantity of "viable Basidiobolus units." Faecal samples of gecko and agama lizards were collected and analysed using spread plating, with confirmation by PCR. The addition of dichloran and benomyl to standard fungal media improved the selectivity and allowed quantification of Basidiobolus spp. in reptile faeces. The amount of Basidiobolus spp. varied between 300 and 1.4 × 10⁶  CFU per gram of pooled gecko faeces, which mostly corresponds to >1000 CFU per outside dropping and <100 CFU per inside dropping. About 60% of analysed agama faeces carried Basidiobolus spp., ranging from 150 to 1.2 × 10⁵  CFU per dropping. Our results show for the first time that faeces of South African reptiles frequently carry Basidiobolus spp., confirming that they can contribute to the distribution of this fungus.