[ Paecilomyces variotii is the asexual state of Byssochlamys spectabilis, a member of the Phylum Ascomycota (Family Trichocomaceae).[4] However, the Byssochlamys state is rarely observed in culture due to the heterothallic nature of this species (i.e., it requires culturing of positive and negative strains in co-culture to produce the teleomorph). Paecilomyces variotii is fast growing, producing powdery to suede-like in colonies that are yellow-brown or sand-colored.[5] It is distinguishable from microscopically from similar microfungi, such as the biverticillate members of the genus Penicillium (affiliated with the genus Talaromyces) by its broadly ellipsoidal to lemon-shaped conidia, loosely branched conidiophores and phialides with pointed tips. Ascospores of the sexual state, B. spectabilis, are strongly heat-resistant. As such, the fungus is a common contaminant of heat-treated foods and juices.[4] It is also known from decaying wood and creosote-treated wood utility poles.[4][5] Paecilomyces variotii has been associated with a number of infective diseases of humans and animals.[9] It is also an important indoor environmental contaminant.[10]]Morphology
The colonies are usually flat, powdery to suede-like and funiculose or tufted.[11] The color is initially white, and becomes yellow, yellow-brown, or sand-colored as they mature. A sweet aromatic odor may be associated with older cultures.[12] Colonies of P. variotii are fast growing and mature within 3 days. Colonies grown on Sabouraud's dextrose agar reach about 7–8 mm after one week. Colonies on CYA are flat, floccose in texture, produce brown or olive brown from conidia, and range in diameter from 30-79 mmn in one week.[13] Colonies on malt extract agar reach 70 mm diameter or more, otherwise very similar in appearance to those on CYA. Colonies on G25N media reach 8–16 mm diameter, similar to on CYA but with predominantly white mycelium. Microscopically, the spore-bearing structures of P. variotii consist of a loosely branched,[14] irregularly brush-like conidiophores with phialides at the tips.[4][11] The phialides are swollen at the base, and gradually taper to a sharp point at the tip.[14] Conidia are single-celled, hyaline, and are borne in chains with the youngest at the base.[4] Chlamydospores (thick-walled vegetative resting structures) are occasionally produced singly or in short chains.[19]
Genetics
This fungus is heterothallic, and mating experiments have shown that P. variotii can form ascomata and ascospores in culture when compatible mating types are present.[1][4] Because of this, the teleomorph of P. variotii, Byssochlamys spectabilis, is rarely observed in cultures from environmental or clinical specimens which tend to be colonized by a single mating type.[4] The genome sequences of two isolates of P. variotii of opposite mating type have been generated.[1]
Ecology
This species is thermophilic, able to grow at high temperatures as high as 50–60 °C.[4][12] It can withstand brief exposures of up to 15 min at 80–100 °C.[26] Accordingly, it typically causes spoilage of food products following pasteurization or other heat-treatments (e.g., curry sauces, fruit juices).[27][28] It also has been reported as a contaminant in salami and margarine.[10] The fungus is known from a number of non-food items including compost, rubber, glue, urea-formaldehyde foam insulation and creosote-treated wooden poles.[10][27] The combination of its ability to survive significant heat stress and its ability to break-down aromatic hydrocarbons has led to interest in P. variotii as a potential candidate organism to assist in bioremediation.
Health significance
Although frequently encountered as a contaminant in clinical specimens, P. variotii is an uncommon causative agent of human and animal infections, but is considered to be an emerging agent of opportunistic disease, particularly in immunocompromised individuals. It has been suggested that the extremotolerant nature of the fungus contributes to the its pathogenic potential. Pneumonia due to P. variotii has been reported, albeit rarely, in the medical literature.[32][33] Most cases are known from diabetics or individuals subject to long-term corticosteroid treatment for other diseases.[34][35] P. variotii has also been reported as a causative agent of sinusitis,[36][37][38] endophthalmitis,[39][40][41] wound infection following tissue transplant,[42] cutaneous hyalohyphomycosis,[43][44][45] onychomycosis,[46] osteomyelitis,[47] otitis media[48] and dialysis-related peritonitis.[9] It has also been reported from mastitis in a goat, and as an agent of mycotic infections of dogs and horses.[50] Besides clinical samples, the fungus is a common contaminant of moisture-damaged materials in the indoor environment including carpet, plaster and wood.[10] It is commonly found in indoor air samples and may contribute to indoor allergy.[10] This species produces the mycotoxin viriditoxin.[10]
References
1. ^{{cite journal | vauthors = Urquhart AS, Mondo SJ, Mäkelä MR, Hane JK, Wiebenga A, He G, Mihaltcheva S, Pangilinan J, Lipzen A, Barry K, de Vries RP, Grigoriev IV, Idnurm A | title = Paecilomyces variotii (Eurotiales) | journal = Frontiers in Microbiology | volume = 9 | pages = 3058 | date = 2018 | pmid = 30619145 | pmc = 6300479 | doi = 10.3389/fmicb.2018.03058 }}
2. ^1 {{cite book | vauthors = Pitt JL, Hocking AD |title=Fungi and food spoilage |edition=3rd |year=2009}}
3. ^1 2 {{cite book | vauthors = Samson RA |title=Paecilomyces and some allied hyphomycetes |journal=Studies in Mycology |year=1974 |volume=6 |pages=1–119 | url = https://www.studiesinmycology.org/sim/Sim06/fulltext.htm | isbn = 978-94-91751-00-4 }}
4. ^1 2 3 4 5 6 {{cite book | vauthors = Samson RA, Houbraken J, Summerbell RC, Flannigan B, Miller JD | chapter = Common and important species of fungi and actinomycetes in indoor environment | veditors = Flannigan B, Samson RA, Miller JD | title = Microorganisms in Home and Indoor Work Environments |year=2001 |pages= 285–473 | isbn = 978-0-203-30293-4 }}
5. ^1 2 {{cite book | vauthors = Samson RA, Hoekstra ES, Frisvad JC |title=Introduction to food- and airborne fungi | edition = 7th | publisher = Centraalbureau voor Schimmelcultures |year=2004 | isbn = 978-90-70351-52-6 }}
6. ^1 2 3 4 5 6 7 8 {{cite journal | vauthors = Houbraken J, Verweij PE, Rijs AJ, Borman AM, Samson RA | title = Identification of Paecilomyces variotii in clinical samples and settings | journal = Journal of Clinical Microbiology | volume = 48 | issue = 8 | pages = 2754–61 | date = August 2010 | pmid = 20519470 | pmc = 2916617 | doi = 10.1128/jcm.00764-10 }}
7. ^1 2 {{cite journal |last=Ellis |first=David | name-list-format = vanc |title=Paecilomyces variotii." Mycology Online |journal=The University of Adelaide |date=May 2001 }}
8. ^1 {{cite journal | vauthors = Piecková ES, Samson RA |title=Heat resistance of Paecilomyces variotii in sauce and juice |journal=Journal of Industrial Microbiology and Biotechnology |year=2000 |volume=24 |issue=4 |pages=227–230 |doi=10.1038/sj.jim.2900794}}
9. ^1 {{cite journal | vauthors = Byrd RP, Roy TM, Fields CL, Lynch JA | title = Paecilomyces varioti pneumonia in a patient with diabetes mellitus | journal = Journal of Diabetes and its Complications | volume = 6 | issue = 2 | pages = 150–3 | year = 1992 | pmid = 1611140 | doi = 10.1016/1056-8727(92)90027-i }}
10. ^1 {{cite journal | vauthors = Eloy P, Bertrand B, Rombeaux P, Delos M, Trigaux JP | title = Mycotic sinusitis | journal = Acta Oto-rhino-laryngologica Belgica | volume = 51 | issue = 4 | pages = 339–52 | date = 1997 | pmid = 9444380 | doi = }}
11. ^1 {{cite journal | vauthors = Otcenásek M, Jirousek Z, Nozicka Z, Mencl K | title = Paecilomycosis of the maxillary sinus | journal = Mykosen | volume = 27 | issue = 5 | pages = 242–51 | date = May 1984 | pmid = 6540366 | doi = 10.1111/j.1439-0507.1984.tb02025.x }}
12. ^1 {{cite journal | vauthors = Thompson RF, Bode RB, Rhodes JC, Gluckman JL | title = Paecilomyces variotii. An unusual cause of isolated sphenoid sinusitis | journal = Archives of Otolaryngology--Head & Neck Surgery | volume = 114 | issue = 5 | pages = 567–9 | date = May 1988 | pmid = 3355698 | doi = 10.1001/archotol.1988.01860170097028 }}
13. ^1 {{cite journal | vauthors = Lam DS, Koehler AP, Fan DS, Cheuk W, Leung AT, Ng JS | title = Endogenous fungal endophthalmitis caused by Paecilomyces variotii | journal = Eye | volume = 13 ( Pt 1) | pages = 113–6 | year = 1999 | pmid = 10396397 | doi = 10.1038/eye.1999.23 }}
14. ^1 {{cite journal | vauthors = Tarkkanen A, Raivio V, Anttila VJ, Tommila P, Ralli R, Merenmies L, Immonen I | title = Fungal endophthalmitis caused by Paecilomyces variotii following cataract surgery: a presumed operating room air-conditioning system contamination | journal = Acta Ophthalmologica Scandinavica | volume = 82 | issue = 2 | pages = 232–5 | date = April 2004 | pmid = 15043549 | doi = 10.1111/j.1600-0420.2004.00235.x }}
15. ^1 {{cite journal | vauthors = Lee J, Yew WW, Chiu CS, Wong PC, Wong CF, Wang EP | title = Delayed sternotomy wound infection due to Paecilomyces variotii in a lung transplant recipient | journal = The Journal of Heart and Lung Transplantation : The Official Publication of the International Society for Heart Transplantation | volume = 21 | issue = 10 | pages = 1131–4 | date = October 2002 | pmid = 12398880 | doi = 10.1016/s1053-2498(02)00404-7 }}
16. ^1 {{cite journal | vauthors = Athar MA, Sekhon AS, Mcgrath JV, Malone RM | title = Hyalohyphomycosis caused by Paecilomyces variotii in an obstetrical patient | journal = European Journal of Epidemiology | volume = 12 | issue = 1 | pages = 33–5 | date = February 1996 | pmid = 8817175 | doi = 10.1007/bf00144425 }}
17. ^1 {{cite journal | vauthors = Naidu J, Singh SM | title = Hyalohyphomycosis caused by Paecilomyces variotii: a case report, animal pathogenicity and 'in vitro' sensitivity | journal = Antonie van Leeuwenhoek | volume = 62 | issue = 3 | pages = 225–30 | date = October 1992 | pmid = 1416918 | doi = 10.1007/bf00582583 }}
18. ^1 {{cite journal | vauthors = Arenas R, Arce M, Munoz H, Ruiz-Esmenjaud J |title=Onychomycosis due to Paecilomyces variotii. Case report and review |journal= Journal de Mycologie Médicale |year=1998 |volume=8 | issue = 1 |pages=32–33}}
19. ^1 {{cite journal | vauthors = Cohen-Abbo A, Edwards KM | title = Multifocal osteomyelitis caused by Paecilomyces varioti in a patient with chronic granulomatous disease | journal = Infection | volume = 23 | issue = 1 | pages = 55–7 | date = 1995 | pmid = 7744494 | doi = 10.1007/bf01710060 }}
20. ^1 {{cite journal | vauthors = Dhindsa MK, Naidu J, Singh SM, Jain SK | title = Chronic suppurative otitis media caused by Paecilomyces variotii | journal = Journal of Medical and Veterinary Mycology | volume = 33 | issue = 1 | pages = 59–61 | year = 1995 | pmid = 7650580 | doi = 10.1080/02681219580000121 }}
21. ^1 2 {{cite journal | vauthors = Rinaldi S, Fiscarelli E, Rizzoni G | title = Paecilomyces variotii peritonitis in an infant on automated peritoneal dialysis | journal = Pediatric Nephrology | volume = 14 | issue = 5 | pages = 365–6 | date = May 2000 | pmid = 10805461 | doi = 10.1007/s004670050775 }}
22. ^1 {{cite journal | vauthors = Marzec A, Heron LG, Pritchard RC, Butcher RH, Powell HR, Disney AP, Tosolini FA | title = Paecilomyces variotii in peritoneal dialysate | journal = Journal of Clinical Microbiology | volume = 31 | issue = 9 | pages = 2392–5 | date = September 1993 | pmid = 8408561 | pmc = 265767 }}
23. ^1 2 {{Cite journal| vauthors = Bainier D |title=Paecilomyces Species. |journal=Paecilomyces Species |date=Nov 2013 |volume=|pages=}}
24. ^1 2 {{cite book | vauthors = de Hoog GS, Guarro J, Gene J, Figueras MJ |title=Atlas of Clinical Fungi | edition = 2nd | volume = 1 | year = 2000 | publisher = Universitat Rovira i Virgili | location = Reus, Spain | isbn = 978-90-70351-43-4 }}
25. ^1 {{cite journal |last=Pitt |first=John | first2 = Ailsa D. | last2 = Hocking | name-list-format = vanc |title=Fungi and Food Spoilage |journal=Sydney: Academic |year=1985 |pages=186–96 }}
26. ^1 {{cite journal | vauthors = Piecková E, Samson RA |title=Heat Resistance of Paecilomyces variotii in Sauce and Juice |journal=Journal of Industrial Microbiology and Biotechnology |year=2000 |volume=24 |issue=4 |pages=227–30 |doi=10.1038/sj.jim.2900794}}
27. ^1 {{cite journal |title=Paecilomyces and Some Allied Hyphomycetes | vauthors = Sampson RA |journal=Transactions of the British Mycological Society |year=1975 |pages=174 | doi =10.1016/s0007-1536(75)80098-2 |volume=64}}
28. ^1 2 {{cite journal | vauthors = Houbraken J, Varga J, Rico-Munoz E, Johnson S, Samson RA | title = Sexual reproduction as the cause of heat resistance in the food spoilage fungus Byssochlamys spectabilis (anamorph Paecilomyces variotii) | journal = Applied and Environmental Microbiology | volume = 74 | issue = 5 | pages = 1613–9 | date = March 2008 | pmid = 18192427 | pmc = 2258620 | doi = 10.1128/aem.01761-07 }}
29. ^1 {{cite journal | vauthors = Vasudevan B, Hazra N, Verma R, Srinivas V, Vijendran P, Badad A | title = First reported case of subcutaneous hyalohyphomycosis caused by Paecilomyces variotii | journal = International Journal of Dermatology | volume = 52 | issue = 6 | pages = 711–3 | date = June 2013 | pmid = 23679876 | doi = 10.1111/j.1365-4632.2012.05761.x }}
30. ^1 {{cite journal | vauthors = Anita KB, Fernandez V, Rao R | title = Fungal endophthalmitis caused by Paecilomyces variotii, in an immunocompetent patient, following intraocular lens implantation | journal = Indian Journal of Medical Microbiology | volume = 28 | issue = 3 | pages = 253–4 | year = 2010 | pmid = 20644318 | doi = 10.4103/0255-0857.66491 }}
31. ^1 {{cite journal | vauthors = Saddad N, Shigemitsu H, Christianson A |title=Pneumonia from Paecilomyces in a 67-year-old immunocompetent man |journal=Chest |year=2007 |volume=132 |issue=4 |pages=710 |doi=10.1378/chest.132.4_meetingabstracts.710}}
32. ^1 {{cite journal | vauthors = Grossman CE, Fowler A |title=Paecilomyces: emerging fungal pathogen |journal=Chest |year=2005 |volume=128 |issue=4 |pages=425S |doi=10.1378/chest.128.4_meetingabstracts.425s}}
33. ^1 {{cite journal | vauthors = Steiner B, Aquino VR, Paz AA, Silla LM, Zavascki A, Goldani LZ | title = Paecilomyces variotii as an Emergent Pathogenic Agent of Pneumonia | journal = Case Reports in Infectious Diseases | volume = 2013 | pages = 1–3 | year = 2013 | pmid = 23819077 | pmc = 3683431 | doi = 10.1155/2013/273848 }}