Mycopathologia vol. 57, 2, pag. 73-76, 1975
OBSERVATIONS OF MICROSPORUM CANIS WITH CRYOSCANNING AND SCANNING ELECTRON MICROSCOPY Susumu WATANABE Department of Dermatology, Kurashiki Central Hospital, Kurashiki, Japan
Abstract
Microsporum canis was observed with cryoscanning and scanning electron microscopy without fixation and dehydration. The former showed the almost native state, and the latter showed the marked shrinkage and distortion.
Introduction
Recently in Japan, dermatomycosis caused by Microsporum canis (M. canis) in breeding animals has increased. This is a report on morphology of the macroconidia, microconidia and hypha of m. canis compared with cryoscanning (CSEM) and scanning electron microscopy (SEM) without fixation and dehydration.
Materials and methods
M. canis was obtained from a patient 12 year old boy, with tinea corporis, who aquired the infection from a breeding persian cat with tinea corporis caused by M. eanis (fig. 1). M. canis was cultivated in rice agar at 25 ~ After eight weeks of cultivation, samples from culture were taken out and placed onto the surface of a specimen holder. After the specimen was frozen rapidly with liquid nitrogen, it was examined in CSEM (SMU 3-CRU) at accelerating voltage 5 KV. The examination of M. canis with SEM (JSM) was as follows. Samples from rice agar were taken out after eight weeks of cultivation. Without fixation and dehydration, samples were rapidly coated with gold and carbon, rotated in a vacuum evaporator. It was examined at accelerating voltage5 KV.
Fig. 1. Macroconidia of M. canis on rice agar after eight weeks incubation at 25 ~ x 330. Results
Observations with cryoscanning electron microscopy Macroconidia, microconidia and hypha were seen in the soft, lively and almost native state. Many globular granules having a diameter of about 2/2 on the surface of macroconidia were observed. These granules showed some fuzzy outlines due to frost. Microconidia with a length 2 to 3/2 was seen (fig. 2~5). Observations with seannin 9 electron microscopy Microeonidia and hypha were seen in coarsely wrinkled and distorted states. The large depression of macroconidia was observed. There were many transformed granules
73
Fig. 2. Cigar shaped macroconidia, microconidia and hypha. CSEM. x 500.
Fig. 3. Macroconidia extended from hypha in the almost native state. CSEM. x 1000.
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Fig. 4. Many granules seen on the surface of macroconidia. CSEM. x 600.
Fig. 5. Many globular granules having a diameter of about 2 # On the surface of macroconidia. CSEM. x 2000.
Fig. 6. Magnification of figure 5. Some fuzzy appearance for frost. CSEM. x 5000.
Fig. 8. Many granules on the surface of macroconidia, and the distortion of macroconidia possibly due to an artefact. SEM. x 5000.
Fig. 7. The coarsely distorted macroconidia, microconidia and hypha. SEM. x 1000.
Fig. 9. The wrinkled and distorted microconidia, and hypha. SEM. x 5000. 75
on the surface of macroconidia with a diameter 0.1 to 3 # (fig. 7-9).
Discussion In SEM the fixation and dehydration of samples are the most important problems in the methods of fixation and dehydration as reported by Barber & Boyde (1) and Boyde & Wood (2). Generally, observation with the quick and simple methods is desired. It is said that with CSEM it is not necessary to fix and dehydrate the samples, and moreover one can examine the samples in the almost native state simply and quickly. The author compared CSEM with SEM using samples of M. canis. The observations with CSEM showed the almost native states, but some fuzzy outlines were seen and are probably due to the frost. On the contrary the observations with SEM showed the marked transformations due to the artefact. From these observations without fixation and dehydration it was clear that CSEM was superior to SEM if the frost could be completely removed. What are the globular granules on the surface of the macroconidia of M. canis ? Such granules have been seen in
Microsporum 9ypseum by Watanabe & Watanabe (3). However, electron microscopic observation of M. canis by Werner, Jolly & Spurlock (4) did not show the presence of such granules. The role of the globular granules on the surface of the macroconidia is uncertain.
Summary The observations of Microsporum canis with cryoscanning and scanning electron microscopy without fixation and dehydration were reported. In the former an almost native state was observed though showing some fuzzy outlines due to frost; in the latter it was shown that marked shrinkage and distortion had occured. There were many granules on the surface of the macroconidia though their function is uncertain.
References 1. Barber, V. C. & A, Boyde. 1968. Scanning electron microscopic studies of cilia. Z. Zellforsch. 84: 269-284. 2. Boyde, A. & C. Wood. 1969. Preparation of animal tissue for surfacescanning electron microscopy. J. Microsc. 90: 221-239
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3. Watanabe, S. & S. Watanabe. 1970. Four cases of tinea corporis caused by microsporum bypseum. Acta Derm. (kyoto). 65: 225-236. 4. Werner, H. J. Jr., H. W. Jolly & B. O. Spurlock. 1966. Electron microscope observations of the fine structure of microsporum canis. J. Invest. Derm. 46: 130-134.
OBSERVATIONS OF MICROSPORUM CANIS WITH CRYOSCANNING AND SCANNING ELECTRON MICROSCOPY Susumu WATANABE Department of Dermatology, Kurashiki Central Hospital, Kurashiki, Japan
Abstract
Microsporum canis was observed with cryoscanning and scanning electron microscopy without fixation and dehydration. The former showed the almost native state, and the latter showed the marked shrinkage and distortion.
Introduction
Recently in Japan, dermatomycosis caused by Microsporum canis (M. canis) in breeding animals has increased. This is a report on morphology of the macroconidia, microconidia and hypha of m. canis compared with cryoscanning (CSEM) and scanning electron microscopy (SEM) without fixation and dehydration.
Materials and methods
M. canis was obtained from a patient 12 year old boy, with tinea corporis, who aquired the infection from a breeding persian cat with tinea corporis caused by M. eanis (fig. 1). M. canis was cultivated in rice agar at 25 ~ After eight weeks of cultivation, samples from culture were taken out and placed onto the surface of a specimen holder. After the specimen was frozen rapidly with liquid nitrogen, it was examined in CSEM (SMU 3-CRU) at accelerating voltage 5 KV. The examination of M. canis with SEM (JSM) was as follows. Samples from rice agar were taken out after eight weeks of cultivation. Without fixation and dehydration, samples were rapidly coated with gold and carbon, rotated in a vacuum evaporator. It was examined at accelerating voltage5 KV.
Fig. 1. Macroconidia of M. canis on rice agar after eight weeks incubation at 25 ~ x 330. Results
Observations with cryoscanning electron microscopy Macroconidia, microconidia and hypha were seen in the soft, lively and almost native state. Many globular granules having a diameter of about 2/2 on the surface of macroconidia were observed. These granules showed some fuzzy outlines due to frost. Microconidia with a length 2 to 3/2 was seen (fig. 2~5). Observations with seannin 9 electron microscopy Microeonidia and hypha were seen in coarsely wrinkled and distorted states. The large depression of macroconidia was observed. There were many transformed granules
73
Fig. 2. Cigar shaped macroconidia, microconidia and hypha. CSEM. x 500.
Fig. 3. Macroconidia extended from hypha in the almost native state. CSEM. x 1000.
74
Fig. 4. Many granules seen on the surface of macroconidia. CSEM. x 600.
Fig. 5. Many globular granules having a diameter of about 2 # On the surface of macroconidia. CSEM. x 2000.
Fig. 6. Magnification of figure 5. Some fuzzy appearance for frost. CSEM. x 5000.
Fig. 8. Many granules on the surface of macroconidia, and the distortion of macroconidia possibly due to an artefact. SEM. x 5000.
Fig. 7. The coarsely distorted macroconidia, microconidia and hypha. SEM. x 1000.
Fig. 9. The wrinkled and distorted microconidia, and hypha. SEM. x 5000. 75
on the surface of macroconidia with a diameter 0.1 to 3 # (fig. 7-9).
Discussion In SEM the fixation and dehydration of samples are the most important problems in the methods of fixation and dehydration as reported by Barber & Boyde (1) and Boyde & Wood (2). Generally, observation with the quick and simple methods is desired. It is said that with CSEM it is not necessary to fix and dehydrate the samples, and moreover one can examine the samples in the almost native state simply and quickly. The author compared CSEM with SEM using samples of M. canis. The observations with CSEM showed the almost native states, but some fuzzy outlines were seen and are probably due to the frost. On the contrary the observations with SEM showed the marked transformations due to the artefact. From these observations without fixation and dehydration it was clear that CSEM was superior to SEM if the frost could be completely removed. What are the globular granules on the surface of the macroconidia of M. canis ? Such granules have been seen in
Microsporum 9ypseum by Watanabe & Watanabe (3). However, electron microscopic observation of M. canis by Werner, Jolly & Spurlock (4) did not show the presence of such granules. The role of the globular granules on the surface of the macroconidia is uncertain.
Summary The observations of Microsporum canis with cryoscanning and scanning electron microscopy without fixation and dehydration were reported. In the former an almost native state was observed though showing some fuzzy outlines due to frost; in the latter it was shown that marked shrinkage and distortion had occured. There were many granules on the surface of the macroconidia though their function is uncertain.
References 1. Barber, V. C. & A, Boyde. 1968. Scanning electron microscopic studies of cilia. Z. Zellforsch. 84: 269-284. 2. Boyde, A. & C. Wood. 1969. Preparation of animal tissue for surfacescanning electron microscopy. J. Microsc. 90: 221-239
76
3. Watanabe, S. & S. Watanabe. 1970. Four cases of tinea corporis caused by microsporum bypseum. Acta Derm. (kyoto). 65: 225-236. 4. Werner, H. J. Jr., H. W. Jolly & B. O. Spurlock. 1966. Electron microscope observations of the fine structure of microsporum canis. J. Invest. Derm. 46: 130-134.
