Studies on histoplasmosis farciminosi (epizootic lymphangitis) in Egypt. Isolation of Histoplasma farciminosum from cases of histoplasmosis farciminosi in horses and its morphological characteristics.
Abstract: Isolation of Histoplasma farciminosum from five horses, showing typical signs of histoplasmosis farciminosi (epizootic lymphangitis) was successfully attempted. The mycelial form of H. farciminosum was isolated on Sabouraud dextrose agar enriched with 2.5% glycerol, brain heart infusion (BHI) agar enriched with 10% horse blood and PPLO dextrose glycerol agar. The last medium proved to be the most effective, both for primary isolation and subculturing of the fungus. It was found that on primary isolation, the lag phase of the mycelial form of the fungus was relatively long, involving 4-8 weeks at 25 degrees C. Colonies of the mycelial form of H. farciminosum appeared on subculture as a yellowish, light brown to deep brown, convoluted, waxy, cauliflower-like growth tending to form scant aerial growth. Conversion of the mycelial form to the yeast form of H. farciminosum was successful by subculturing either on BHI agar with 5% blood or on Pine's medium and incubating at 35-37 degrees C. Complete conversion to the yeast form was achieved only after 4-5 repeated serial transfers onto fresh media every 8 days. The yeast colonies were flat, raised, slightly or deeply wrinkled, white to light gray to grayish brown, and were pasty in consistency.
Publication Date: 1985-06-01 PubMed ID: 3842362DOI: 10.1007/BF00141797Google Scholar: Lookup
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Summary
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The article presents the research results on isolating Histoplasma farciminosum, a fungus causing histoplasmosis farciminosi in horses, and presents its morphological characteristics. The research also studies the transformation of this fungus from the mycelial form to the yeast form.
Isolation of Histoplasma Farciminosum
- From five horses showing typical signs of histoplasmosis farciminosi, scientists managed to extract and isolate the Histoplasma farciminosum, a specific type of fungus.
- Sabouraud dextrose agar enriched with 2.5% glycerol, brain heart infusion agar enriched with 10% horse blood, and PPLO dextrose glycerol agar were all used for the isolation. However, the PPLO dextrose glycerol agar proved to be the most effective in terms of primary isolation and subculturing.
- Initial isolation revealed that the mycelial (fungi’s vegetative part) form of the fungus goes through a lag phase of between 4 to 8 weeks at a temperature of 25 degrees C.
Characteristics of the Mycelial Form
- Upon subculturing, colonies of the mycelial form showed up as a yellowish, light brown to deep brown, convoluted, waxy, cauliflower-like growth with minimal aerial growth.
Conversion to the Yeast Form
- The conversion of this mycelial form of H. farciminosum fungus into its yeast form was achieved by subculturing it either on BHI agar with 5% blood or on Pine’s medium and then incubating it at a temperature between 35-37 degrees C.
- This conversion was only possible after 4-5 repeated rounds of serial transfers onto fresh media every 8 days.
- Complete transformation of the fungal form resulted in yeast colonies that were flat, raised, slightly or deeply wrinkled, ranging in color from white to light gray or grayish brown and acquiring a pasty consistency.
Cite This Article
APA
Selim SA, Soliman R, Osman K, Padhye AA, Ajello L.
(1985).
Studies on histoplasmosis farciminosi (epizootic lymphangitis) in Egypt. Isolation of Histoplasma farciminosum from cases of histoplasmosis farciminosi in horses and its morphological characteristics.
Eur J Epidemiol, 1(2), 84-89.
https://doi.org/10.1007/BF00141797 Publication
Researcher Affiliations
MeSH Terms
- Animals
- Culture Media
- Histoplasma / cytology
- Histoplasma / growth & development
- Histoplasma / isolation & purification
- Histoplasmosis / microbiology
- Histoplasmosis / veterinary
- Horse Diseases / microbiology
- Horses
- Lymphangitis / microbiology
- Lymphangitis / veterinary
References
This article includes 6 references
- Fouad K, Saleh MS, Sokkar S, Shouman MT. Studies on lachrymal histoplasmosis in donkeys in Egypt.. Zentralbl Veterinarmed B 1973 Oct;20(8):584-93.
- Fawi MT. Histoplasma farciminosum, the aetiological agent of equine cryptococcal pneumonia.. Sabouraudia 1971 Jul;9(2):123-5.
- Refai M, Loot A. Incidence of epizootic lymphangitis in Egypt with reference to its geographical distribution.. Mykosen 1970 May 1;13(5):247-52.
- PINE L, DROUHET E. [ON INDUCTION AND PRESERVATION OF THE YEAST PHASE OF HISTOPLASMA CAPSULATUM AND H. DUBOISI IN A CHEMICALLY DEFINED MEDIUM].. Ann Inst Pasteur (Paris) 1963 Oct;105:798-804.
- Ajello L. Comparative morphology and immunology of members of the genus Histoplasma. A review.. Mykosen 1968 Jul 1;11(7):507-14.
- Abou-Gabal M, Hassan FK, Al-Siad AA, Al-Karim KA. Study on equine histoplasmosis "epizootic lymphangitis".. Mykosen 1983 Mar;26(3):145-51.
Citations
This article has been cited 5 times.- Ameni G, Messele Kebede A, Zewude A, Girma Abdulla M, Asfaw R, Gobena MM, Kyalo M, Stomeo F, Gumi B, Sori T. Equine Histoplasmosis in Ethiopia: Phylogenetic Analysis by Sequencing of the Internal Transcribed Spacer Region of rRNA Genes. Front Cell Infect Microbiol 2022;12:789157.
- Rodrigues AM, Beale MA, Hagen F, Fisher MC, Terra PPD, de Hoog S, Brilhante RSN, de Aguiar Cordeiro R, de Souza Collares Maia Castelo-Branco D, Rocha MFG, Sidrim JJC, de Camargo ZP. The global epidemiology of emerging Histoplasma species in recent years. Stud Mycol 2020 Sep;97:100095.
- Hadush B, Michaelay M, Menghistu HT, Abebe N, Genzebu AT, Bitsue HK, Afera B, Duguma BE, Gugsa G, Ameni G. Epidemiology of epizootic lymphangitis of carthorses in northern Ethiopia using conventional diagnostic methods and nested polymerase chain reaction. BMC Vet Res 2020 Oct 7;16(1):375.
- Teixeira Mde M, Patané JS, Taylor ML, Gómez BL, Theodoro RC, de Hoog S, Engelthaler DM, Zancopé-Oliveira RM, Felipe MS, Barker BM. Worldwide Phylogenetic Distributions and Population Dynamics of the Genus Histoplasma. PLoS Negl Trop Dis 2016 Jun;10(6):e0004732.
- Alpysbayeva SE, Abdykalyk AA, Tileukhanov K, Abdimukhtar AR, Toleukhan AT, Sarmykova MK, Anarbekova AM, Shayakhmetov YA, Syrym NS, Nurabaev SS, Yespembetov BA. Evaluating the Biochemical and Haematological Safety of the Histoplasma capsulatum var. farciminosum '8ZH' Vaccine in Foals. Vet Med Sci 2026 Jan;12(1):e70764.
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