Tag Archives: basidiobolus

Basidiobolus! – genus of the month at ATCC

ATCC sent out this email with the Genus of the month as Basidiobolus. It is worth noting they call out B. ranarum as inhabitant of bat and rodent guts but it is mainly known (and named) for being associated with frogs (hence the ‘rana’). It has some quite cool biology, it grows dimorphically as a yeast or hyphae, and is reported to have a large genome (Henk and Fisher PLoS One 2012).
Note that the genome and transcriptome of B. meristosporus is being sequenced as part of the 1000 Fungal genomes project from samples Andrii Gryganski prepared. Don’t forget that YOU can propose genomes to this project by logging in here and submitting a proposed species in a family that is not sufficiently sampled (2 per Family).

The info below is from ATCC®. I couldn’t find a link to the on their site so I am copying the email text in.

There is nothing more fascinating than when a microbial species begins popping up in the literature as a true pathogen. Basidiobolus ranarum, which typically inhabits the guts of bats and small rodents, has been recently tagged as an emerging human pathogen that may have previously been unrecognized.1

       B. ranarum was first added to the CDC’s Morbidity and Mortality Weekly Report (MMWR)1 in 1999 after 6 immunocompetent individuals tested positive for gastrointestinal basidiobolomycosis over a 5-year period. The most interesting aspect of this study, however, was the fact that each patient was originally misdiagnosed with some other intestinal ailment, ranging from diverticulitis to cancer.

While many of the Zygomycetes, including Basidiobolus, have been implicated in subcutaneous human diseases, it is still relatively uncommon for Basidiobolus to colonize the human intestine. This new development piqued the interest of several researchers at the Mayo Clinic in Scottsdale, Arizona, a region of the U.S. where the majority of such cases have been reported.  Following an in-depth analysis of all known case records, they discovered a total of 44 cases of gastrointestinal basidiobolomycosis worldwide; 19 of which occurred in the southwestern U.S., 11 in Saudi Arabia, and 14 in other arid regions of the globe.2

Symptoms displayed in each case were similar, with complaints ranging from abdominal distention and pain to a palpable abdominal mass. Of particular interest was a patient originally treated for Clostridium difficile colitis. This patient underwent several surgeries and treatment with oral vancomycin before a stool fungal culture revealed the presence of B. ranarum. While this patient was successfully treated with a 3-month course of voriconazole, repeated at 1-year follow-up, the investigators cautioned that antifungal resistance may pose a problem in the future. Earlier work performed by the same group revealed uniform resistance to amphotericin B and flucytosine in four  B. ranarum isolates, as well as mixed resistance to several other azoles.2

The source of B. ranarum infection leading to gastrointestinal disease is still not understood, but the fecal-oral route has been suggested. Pathologists and clinicians should be aware of this potential new threat, and additional work to understand the pathogenesis and antifungal susceptibility/resistance of B. ranarum should be an on-going effort among the research and medical communities.

ATCC® Basidiobolus Strains
Want to learn more about ATCC Basidiobolus strains available from ATCC? View a list of Basidiobolus spp. online.

References

1. Centers for Disease Control and Prevention (CDC). MMWR: Gastrointestinal Basidiobolomycosis – Arizona, 1994-1999. August 20, 1999.

2. Vikram, et al. Emergence of Gastrointestinal Basidiobolomycosis in the United States, with a Review of Worldwide Cases. Clinical Infectious Diseases Advance Access published on March 22, 2012.

Escaping the dung pile quickly: Speedy Pilobolus spores

ResearchBlogging.orgSporangiophore discharge in the fungus <em/>Pilobolus kleinii captured with high speed video. In a paper appearing today in PLoS One, “The Fastest Flights in Nature: High-Speed Spore Discharge Mechanisms among Fungi” Nicholas Money and colleagues including 6 undergraduates and 3 graduate students, have measured the speed of flight of spores discharging from several Ascomycete and Zygomycete dung fungi including Pilobolus kleinii, Basidiobolus ranarum, Podospora anserina, and Ascobolus immersus. The team used high speed cameras that recorded at 250,000 frames per second and were able to capture spores being launched at 25 meters per second at accelerations of 180,000 g. The publication also provides multimedia including a video of the spore discharge slowed down and set to music. Nik and Mark Fisher both presented portions of the work at the Mycological Society of America 2008 meeting this summer and showed clips of these dramatic videos, so it was great to see this in print shortly following the meeting.

By way of the press release the major findings from this work show that

… the discharge mechanisms in fungi are powered by the same levels of pressure that are characteristic of the cells that make up the feeding colonies of fungi. Therefore, the long flights enjoyed by spores result not from unusually high pressure, but from the way in which explosive pressure loss is linked to the propulsion of the spores. There appear to be some similarities between the escape of the spores and the expulsion of ink droplets through nozzles on inkjet printers.

As Dr Money has described in a humorous and humble manner before in his Mr Bloomfield’s Orchard, some of the coolest and fundamental observations about spore flight and discharge, from Buller to the present, have come from simple and careful observations of fungi. In this case they have used a new tools of ultra high speed photography to capture events. Some of the previous work from the Money lab on this front include a demonstration that conidia are actively launched and rather than being passively released by low velocity airflow in the toxic indoor mold Stachybotrys (Tucker et al FGB 2007; free at PMC)

Yafetto L, Carroll L, Cui Y, Davis DJ, Fischer MWF,Henterly AC,, Kessler JD, Kilroy HA, Shidler JB, Stolze-Rybczynski JL, Sugawara Z, Money NP (2008). The Fastest Flights in Nature: High-Speed Spore Discharge Mechanisms among Fungi PLoS One, 3 (9) DOI: 10.1371/journal.pone.0003237