Isolation Of Pathogenic Fungi Research Articles

Effect of gentamicin on growth of yeasts, yeast-like organisms, and Aspergillus fumigatus.

The growth of 26 strains of various Candida species, five strains each of Torulopsis glabrata and Aspergillus fumigatus , two strains of Saccharomyces cervisiae , and six strains of various Cryptococcus species was studied on inhibitory mold agar with and without gentamicin at 5 μ g. per ml. There was no apparent inhibition of the organisms tested by the concentration of gentamicin used. This study gives further support to the use of gentamicin as a bacterial inhibitor in media used for the isolation of pathogenic fungi.

The isolation of pathogenic fungi from sodium hydroxide-processed sputum specimens from patients suspected to have tuberculosis.

Specimens received for tuberculosis bacteriology from 1966 to 1969 were processed by the sodium hydroxide technic. Occasionally, these specimens produced fungi on the Lowenstein-Jensen and Middlebrook-Cohn 7H-10 media. Attempts to determine whether these isolates had pathogenic potential revealed that 23 of the 860 fungal isolates were known pathogens. Allescheria boydii, Aspergillus fumigatus and Nocardia asteroides were among those isolated. Although the ratio of pathogenic to saprophytic fungal isolates in this study was small, it is significant to learn that it is possible to isolate and identify some pathogenic fungi when using this relatively lethal digestion procedure for routine mycobacterial isolation.

Optimal combination and concentration of antibiotics in media for isolation of pathogenic fungi and Nocardia asteroides.

Strains of Blastomyces dermatitidis, Sporothrix schenckii, Histoplasma capsulatum, Cryptococcus neoformans, Nocardia asteroides, and Coccidioides immitis were tested for in vitro susceptibility to polymyxin, gentamicin, kanamycin, chloramphenicol, and neomycin at concentrations of 1, 2, 4, 8, and 16 mug/ml. Polymyxin was the most inhibitory and gentamicin was the least inhibitory of the five antibiotics. Two Histoplasma mycelial strains were partially inhibited by 2 and 8 mug of gentamicin per ml and showed at least a 2+ growth at the higher antibiotic concentration. Kanamycin and neomycin produced significant inhibition of N. asteroides but otherwise were noninhibitory. A combination of chloramphenicol and kanamycin, each at 16 mug/ml, and gentamicin, at 4 mug/ml, was noninhibitory to the strains tested except for N. asteroides. Chloramphenicol at 16 mug/ml was not inhibitory for N. asteroides. The results suggest that the optimal antibiotic combination to use in the isolation of fungi and higher bacteria is chloramphenicol, 16 mug/ml, and gentamicin, 4 mug/ml. Addition of sheep blood (5%) had no effect on antibiotic susceptibility of the organisms studied.

Optimal Combination and Concentration of Antibiotics in Media for Isolation of Pathogenic Fungi and Nocardia asteroides

Strains of Blastomyces dermatitidis, Sporothrix schenckii, Histoplasma capsulatum, Cryptococcus neoformans, Nocardia asteroides, and Coccidioides immitis were tested for in vitro susceptibility to polymyxin, gentamicin, kanamycin, chloramphenicol, and neomycin at concentrations of 1, 2, 4, 8, and 16 mug/ml. Polymyxin was the most inhibitory and gentamicin was the least inhibitory of the five antibiotics. Two Histoplasma mycelial strains were partially inhibited by 2 and 8 mug of gentamicin per ml and showed at least a 2+ growth at the higher antibiotic concentration. Kanamycin and neomycin produced significant inhibition of N. asteroides but otherwise were noninhibitory. A combination of chloramphenicol and kanamycin, each at 16 mug/ml, and gentamicin, at 4 mug/ml, was noninhibitory to the strains tested except for N. asteroides. Chloramphenicol at 16 mug/ml was not inhibitory for N. asteroides. The results suggest that the optimal antibiotic combination to use in the isolation of fungi and higher bacteria is chloramphenicol, 16 mug/ml, and gentamicin, 4 mug/ml. Addition of sheep blood (5%) had no effect on antibiotic susceptibility of the organisms studied.

Selective Media for Isolation of Pathogenic Fungi

Selective Media for Isolation of Pathogenic Fungi

Isolation of pathogenic fungi from nature and their pathogenicity

Isolation of pathogenic fungi from nature and their pathogenicity

The isolation of pathogenic fungi from the soils of Egypt, the Sudan, and Ethiopia.

Soils collected from selected sites in Egypt, the Sudan, and Ethiopia were examined for the presence of pathogenic fungi by utilizing hair baiting and animal injection techniques. M. gypseum and M. apiospermum was recovered from soils from all 3 countries. K. ajelloi was isolated from Egyptian and Ethiopian soils but not from those from the Sudan. Macroconidia resembling those of M. cookei were observed microscopically on hair bait that had been placed on soil collected in the Sudan. Isolation of this strain was not successful. No recoveries of systemic fungi are reported. Dans des échantillons de sols prélevés en divers lieux sélectionnés en Egypte, au Soudan et en Ethiopie, on a recherché la présence de champignons pathogènes en utilisant les techniques de piégeage sur kératine et d'injection aux animaux de laboratoire. Microsporam gypseum et Monosporium apiospermum ont été isolés à partir des sols des trois pays. Keratinomyces ajelloi a éte isolé des sols provenant d'Egypte et d'Ethiopie mais non de ceux provenant du Soudan. Sur des poils placés sur les échantillons de sols prélevés au Soudan, des macroconidies semblables à celles de Microsporum cookei ont été observées au microscope. L'isolement de cette souche n'a pas été possible. Aucun champignon de mycoses profondes n'a été obtenu.

Use of desertomycin medium in routine selective isolation of fungi pathogenic to man.

THE isolation of pathogenic fungi producing superficial or systemic diseases in man from clinical materials is made difficult by different contaminating bacteria and saprophytic fungi overgrowing the culture medium and suppressing or inhibiting the growth of pathogenic fungi. In order to obtain pathogenic fungi in a pure culture, attempts were made to mix various substances in the medium in such a way that they would be liable to prevent the growth of contaminants. After a great deal of effort, the most satisfactory result was obtained by cultivation media containing actidione. Actidione (cycloheximide)2 was the only antifungal antibiotic which, though exerting no antibacterial effect, inhibits the growth of most saprophytic fungi, yet does not inhibit the development of fungi pathogenic to man. For this very reason, it can be used with penicillin and streptomycin2,3 or chloramphenicol4 for the preparation of selective culture media.

Use of achromycin in the preparation of selective media for fungi.

The isolation of pathogenic fungi from heavily contaminated material has always been difficult uptil now. Brain Heart Infusion medium containing 30 units of penicillin and 40 units of streptomycin has been found to be the best medium for the isolation of pathogenic fungi. Better results have been obtained by using Achromycin in place of penicillin and streptomycin.

Microbial growth stimulants in spleen.

PREVIOUS studies have revealed that rabbit spleen contains unidentified, water-soluble substances that are growth stimulatory for Escherichia coli1, and also that beef spleen yields heat-resistant, water-soluble extractives stimulatory for species of pathogenic fungi2. A blood agar medium incorporating aqueous spleen infusion was formulated for the isolation of pathogenic fungi at 37° C.2. The stimulatory effects of spleen extracts on the growth of micro-organisms in chemically defined culture media has been investigated by us.

A New Species of Trichophyton from New South Wales

Recent work on the isolation of pathogenic fungi, including dermato? phytes, has been briefly reviewed in a previous paper (4). In the course of investigating a series of samples of soil for the presence of keratino? philic fungi, a new species of Trichophyton has been encountered. It was isolated from two different samples of soil by a technique described by Vanbreuseghem (8) and modified by Ajello (1).

The Usefulness of the Hotchkiss-McManus Stain for the Diagnosis of the Deep Mycoses

The isolation of pathogenic fungi is more difficult than most physicians appreciate and the average hospital bacteriology laboratory approaches the problem in a half-hearted and uninstructed manner. Too often the diagnosis is a “coup de grace” administered by the pathologist at the clinical pathological conference. As a matter of fact, a considerable number of deep mycoses must go unrecognized each year despite the provision of adequate material to the pathologist for at least a tentative diagnosis. There are a number of reasons for this state of affairs; the two which are outstanding implicate both the clinician and the pathologist.

Collecting specimens for the laboratory demonstration and isolation of fungi.

Clinical laboratory procedures in medical mycology are directed toward the demonstration and isolation of pathogenic fungi occurring in body tissues and fluids. The diagnostic laboratory, however, cannot function unless adequate specimens, properly collected and handled, are received. This paper has been prepared to assist clinicians in the collection of appropriate specimens from patients suspected of having mycotic infection. In general, the procedures involved are simple, and no elaborate equipment is required. The types of specimens needed to demonstrate these fungi and to isolate them from clinical materials will be described for the following groups of fungus infections and for each specific disease. SUPERFICIAL MYCOSES These are fungus infections confined to the outermost layer of the skin and hair. The diseases included in this category are (1) erythrasma, (2) piedra, (3) tinea nigra, (4) tinea versicolor and (5) trichomycosis axillaris. The mycotic nature of erythrasma, tinea nigra and tinea versicolor is

Isolation of Pathogenic Fungi from Experimentally Inoculated Guinea Pigs

Isolation of Pathogenic Fungi from Experimentally Inoculated Guinea Pigs

Potassium Tellruite and Copper Sulphate in Sabouraud’s Medium for Isolation of Pathogenic Fungi

Potassium Tellruite and Copper Sulphate in Sabouraud’s Medium for Isolation of Pathogenic Fungi

Potassium Tellurite and Copper Sulphate in Sabouraud's Medium for Isolation of Pathogenic Fungi

In the isolation of pathogenic fungi, one of the principal difficulties is the occurrence of bacterial contamination. This is particularly true when dealing with scales and crusts which are usually loaded with saprophytic bacteria. In trying to overcome this difficulty we have found potassium tellurite and copper sulphate to be of value as by incorporating them into Sabouraud's medium they are found to be capable of suppressing the growth of bacteria but not that of fungi. In reviewing the literature, we have been able to find few reports in which chemicals were incorporated in Sabouraud's medium for the inhibition of contaminants. Sauthof1 found that with stock cultures, 1-2% of yatren in Sabouraud's medium was able to inhibit the growth of staphylococcus but not of fungi. In our study the experimental material was taken directly from lesions of fungous infections since it seemed more practical to work with actual specimens than with stock cultures. The details of this study are presented below.Different...