Mycological studies of candida species isolated from vagina
In 1751. John Hill observed yeast-like organisms which he named monilia. Berkhaut gave another nomenclature, candida, which is used today. Among the more than a hundred reported strains of the candida species, Candida albicans was reported by Benham to be the sole pathogenic organism. This was later confirmed by Lodder and kreger-Van Rij.
Some candida species are known to be normal flora which inhabit the oral cavity, bronchus, intestinal lumen and vagina residently or transiently. Candida. however, can show severe pathogenic activities, associated with such predisposing factors as general weakness, diabetes melitus, malnutrition and suppression of normal flora by abusing or mis-using antibacterial agents. The first isolation of Candida from the skin was reported by Epstein; Bret et al. and Mackenzie reported candida species in the oral cavity was the causative organism of oral thrush. Severe candidiasis has also been reported by many workers(Moulder, Chisholm, Pasternack, and etc.)
Various methods of identification of candida have been reported recently developed fluorescent antibody techniques are considered to be the most advanced method of identification. Treatment for candidiais, including antimycotic agents, have been developed. In addition to studied of the candida species, the effect of several antimycotic agents has been analyzed on isolated yeast-like organism. The antimycotic activity was evaluated by comparison with standard strains kindly received from Dr. S.B. Suh in Tae-Ku.
There have been several explanations for the increased candidal growth shown in patients on antibiotics. Some studies on the effect of antibiotics on pure cultures of candida have shown that pure chlortetracycline increases the growth of candida.
The author has observed candida distribution through isolating the specimen from the vagina and studying the effects of various antimycotic agents on candidasis.
Materials and Methods
Specimens were collected from women sho visited this Medical Center. Yeast-like cells were obtained by culturing the specimens on Sabouraud's solid media after microscopic confirmation. Identification of candida was done to determine whether the biochemical and immunological characteristics would show standard patterns.
Evaluations of antimycotic activities: The mechanism of the acquirement of resistance to the candida species is still obscure: many workers are now investigating this problem. Resistant patters were evaluated through subinoculation into a medium containing serially diluted concentrations o the antimycotic agents, and through a careful study of resistant patterns.
Clinical symptoms of candida carriers: The relationship between the clinical symptoms and organisms was studied.
Electron microscopic observations: The morphological changes induced by treatment with various reagents. For this examination, the colonies which had been cultured in the liquid media were centrifuged and fixed with 1 per cent osmium tetraoxide.
After the fixation and embedment of Epon 812, electron microscopic examination was performed with an HU-11 electron micro-scope manufactured by Hitachi Co.
The following results were observed on the identification and distribution of candida species in the vaginea of women and on the antimycotic effect of various therapeutics on candida. Electron microscopic findings were also studied for candida treated with antimycotic agents.
1. Observation of the organism:
The per cent of 15.2(252 cases) of a total of 1,660 cases showed the candida organisms. In the remaining 84.8 per cent (1,408 cases), no organisms could be found.
2. Identification of the organism:
Among the isolated 252 cases, 179 cases or 71.0 per cent were identified as candida while the remaining 73 cases or 29 per cent were unclassified. The distribution of the 179 identified as candida were as follows. C. albicans, 55 cases 21.0 per cent: C. Krusei, 53 cases or 21.0 per cent; C. stellatoidea, 20 cases or 17.9 per cent; C. tropicalis, 13 cases or 17.1 per cent and C.guilliermondii, 8 cases or 3.2 per cent.
3. Observation of antimycotic activities:
1) Antimycotic activity of gentian violet
In an experiment to determine the antimycotic activity of gentian violet, no remarkable difference could be observed between the control group and experimental group, but between each group of candida species there was some significant
difference in the minimum concentration of gentian violet necessary for a growth inhibiting effect. The minimum concentration for growth inhibiting effect in the control groups were as follows; C. albicasn, C. Krusei, C.stellatoidea, C.
tropicalis and C. parakrusei were 1 γ per ml and C. pseudotrioucalis and C.guiliermondii were 5 γper ml. The results of the same experiment in the experimental group are as follow: C. albicans 5 to 10γ per ml, C. parakrusei 1 to 5 γ per ml, C. stellatoidea 1 to 5 γ ml, C. psedudo tropicalis 1 γ per ml. C.
tropicalis 10γ per ml, C. guilliermondii 5γ per ml. and C. krusei 1 to 5γ per Growth inhibition action of gentian violet required a higher concentration of the agent in the experinental than in the control group.
2) Antimycotic activities of Nystatin
Any remarkable difference in antimycotic activity could not be observed between the control and experimental groups in the experiment to determine the effect of nystatin. The minimal concentrations of nystatin necessary for the antimycotic effect was in the range of 1 to 10 unit per ml. in most groups, but C. krusei of the control group showed active growth at a nystatin concentration of 40 unit per ml. In C. krusei of the experinental group, a lower concentration of nystatin was sufficient enough to inhibit growth; i.e. the growth of most C. krusei was impossible at the level of 20 unit per ml. However, some members of C.krusei in the expermental group showed active growth at a concentration of 80 unit per ml.
3) Antimycotic activity of penbritin
No remarkable antinycotic activity could be observed with penbritin, since growth of the organism was not inhibited at a concentiation of 1,000γ per ml. both in the control and in the experimental groups.
4) Antimycotic acitivity of trichomycin
As in the other experiments, no difference was noted between the control and the experimental groups and also between the various groups of different strains. Growth inhibiting effect was observable at a concentration of 1 to 5 unit per ml; to inhibit the growth of C. pseudotropicalis 10 unit per ml. was necessary.
Comparing the result of the control group with that of the experinemental groups, a higher concentration (5 to 20 unit per ml) was necessary for growth inhibition in the experimental groups.
4. The relation between clinical symptoms and condida species isolated:
A study on the clinical significance of candida species revealed the C. albicans and C. krusei group had some relationship with the clinical symptoms.
5. The patterns of resistance:
Progressive resistance was observed in most of the therapeutic agents, except for gentian violet. The concentration of therapeutic agents necessary for the inhibition of growth of the organisms showed a progressive increase for 10 generations. The development of inhibition phenomenon was shown to be relatively
high in the experimental groups. In the control group the result of testing for resistance showed a resistance to all the drugs except gentian violet.
6. Electron microscopic findings:
A definite increase in the cell wall formation in the 3 groups(nystatin, trichomycin and pimaricin treated) was observed through the electron microscopic observation, however, no such effect was observed observations, in the gentian violet group.