William Kaplan

RECENT DEVELOPMENTS IN ANIMAL RINGWORM AND THEIR PUBLIC HEALTH IMPLICATIONS

The ability to break down keratin is an important characteristic of the dermatophytes. In vioo, these fungi are parasites of the keratinized tissues of the body, such as the epidermis, the hair, and the nails, and they produce alterations of the structures invaded. These alterations, together with attendant immunological reactions, are clinically classified as ringworm. Both man and the lower animals are susceptible to infection by ringworm fungi. However, the individual dermatophyte species show varying degrees of host specificity. Some are parasites of man, and these rarely, if ever, infect lower animals; others are primarily animal pathogens that are found to produce human disease on occasion. Thus, on the basis of host preference or host adaptation, the ringworm fungi have been divided into two groups. In one category have been placed the human pathogens or anthropophilic organisms and, in the other, the animal pathogens or zoophilic dermatophytes. While it is true that some of the human and animal pathogens have been recovered from the contaminated environment of infected hosts1e3 such apparent saprophytism appears to be secondary to their parasitism of man or animals. Until recently, nearly all of the known dermatophytes have been placed in one or the other of these two groups. Recent findings, however, point to the necessity of establishing still another category of dermatophytes, one that would draw its members from among the keratinophilic soil-inhabiting fungi that have the ability, under certain conditions, to invade the keratinized tissues of human and animal hosts and there to produce disease. Members of this group are essentially saprophytes and, probably, serve along with other keratinophilic organisms in the microbiological breakdown in soil of keratin into simple Plements. To date, only two species, Microsfiorum gypseum4j u and Keratinomyces ajelloi6-8 have been demonstrated to belong in this third category. Thus, from an epidemiological standpoint it is logical, a t this time, to consider the existence of these three groups of ringworm fungi: the anthropophilic or “human-type” organisms, the zoophilic or “animal-type” organisms, and the “geophilic” or soil organisms. hiembers of the three groups of dermatophytes are involved in human disease, and each type presents distinct public health problems. As might be anticipated, the vast majority of ringworm infections in man are caused by anthropophilic organisms. Such conditions as “athlete’s foot,” and ringworm of the groin and nails are comrnon conditions affccting large segments of our population. They are caused by anthropophilic dermatophytcs, and animals have not been shown to play a role in the cpidemiology of thcse diseases. IIowever, if one excludes these common infections and considers only ringworm of the exposed parts of the body, such as the scalp, face, neck, and extremities, then the zoophilic organisms appear as important contributors to human

Disseminated Bilateral Chorioretinitis due to Histoplasma capsulatum in a Patient with the Acquired Immunodeficiency Syndrome

A 31-year-old white male homosexual was healthy until March 1984, when he developed Pneumocystis carinii pneumonia, which resolved with treatment. In April 1984 he developed fever, followed by hepatosplenomegaly, headaches, blurred vision, pancytopenia and pulmonary infiltrates. On June 11, intracytoplasmic yeast were noted within leukocytes on a peripheral blood smear, and amphotericin B was started. The patient developed progressive respiratory and renal insufficiency and died on June 13, 1984. Autopsy histopathology demonstrated disseminated histoplasmosis and Histoplasma capsulatum was cultured from numerous tissues. Ocular histopathologic examination using special fungal stains and electron microscopy revealed numerous budding yeasts characteristic of Histoplasma capsulatum in the choroid, retina and central retinal vein. Their identification as H. capsulatum was confirmed by immunofluorescent staining.

Observations on the seasonal variations in incidence of ringworm in dogs and cats in the United States

The data presented in this report suggest that seasonal variations occur in the incidence of ringworm in dogs and cats in the United States. In addition, it appears that the incidence patterns, when discernible, vary with the dermatophyte involved.

A New Variant of Sporothrix Schenckii

Clinically sporotrichosis manifests itself in a wide variety of forms. These range .from the classical type with linear lymphatic involvement to fixed and disseminated forms. But regardless of these variations, histologically all reveal, with appropriate stains, similar tissue form cells of the etiologic agent. In tissues Sporothrix schenckii produces polymorphic, unicellular cells that reproduce by budding. These cells, some of which are referred to as “cigar-bodies,“ range in size from 2 to 4 p in diameter to 4-6 p. in length. Receipt of photographs and histological material from experimentally infected rats, and a culture from a fixed type of sporotrichosis with tissue-form cells that differed significantly from those regularly noted in this disease prompted a detailed study of the isolate and publication of our findings. The material was submitted to us by Dr. HARRY L. LURIE of the Medical College of Virginia, Richmond, Virginia. It had been obtained by Dr. LURIE while he was a staff member of the South African Institute for Medical Research Johannesburg, South Africa. Pertinent details of the case are excerpted from a communication sent to Dr. LURIE by Dr. Samuel W. HYND of the Raleigh Fitkin MemoriaI Hospital, Bremersdorp, Swaziiand, South Africa.

Specific Fluorescent Antiglobulins for the Detection and Identification of Blastomyces dermatitidis Yeast-Phase Cells.

Two lots of rabbit anti-Blastomyces dermatitidis globulins were conjugated with fluorescein isothiocyanate. These reagents stained brightly elements of the yeast and mycelial phases of 10 strains ofB. dermatitidis. In addition, the labeled antibodies cross-reacted with elements of the yeast and mycelial phases of 7 strains ofHistoplasma capsulatum and cells of numerous other heterologous fungi. Adsorption of one lot of labeled antibodies twice with yeast cells ofH. capsulatum and once with elements ofGeotrichum candidum rendered the conjugate specific for the yeast phase ofB. dermatitidis. Three adsorptions with yeast cells ofH. capsulatum followed by a single adsorption with elements ofG. candidum rendered the second conjugate specific for yeast-phase cells ofB. dermatitidis. The specific reagents did not react with the mycelial phase of this fungus.Two lots of rabbit anti-Blastomyces dermatitidis globulins were conjugated with fluorescein isothiocyanate. These reagents stained brightly elements of the yeast and mycelial phases of 10 strains ofB. dermatitidis. In addition, the labeled antibodies cross-reacted with elements of the yeast and mycelial phases of 7 strains ofHistoplasma capsulatum and cells of numerous other heterologous fungi. Adsorption of one lot of labeled antibodies twice with yeast cells ofH. capsulatum and once with elements ofGeotrichum candidum rendered the conjugate specific for the yeast phase ofB. dermatitidis. Three adsorptions with yeast cells ofH. capsulatum followed by a single adsorption with elements ofG. candidum rendered the second conjugate specific for yeast-phase cells ofB. dermatitidis. The specific reagents did not react with the mycelial phase of this fungus.

Pulmonary mucormycosis in a harp seal caused by Mucor pusillus.

Mucormycosis, a disease caused by fungi belonging to the class Phycomycetes, usually of the order Mucorales, has been reported in both man (BAUER, et al., 1955, BAKER, 1957) and lower animals (AINSWORTH & AUSTWlCK, 1959). The organisms classified in this botanical category are widely disseminated in nature and are not usually considered to be animal pathogens. They are found in soil, water, food and decomposing organic matter where they exist in a free-living state. Although man and lower animals are frequently exposed to these organisms in nature, phycomycete infections are encountered infrequently. In humans, diabetes mellitus, leukemia and other debiliating diseases (BAUER, et al., 1956, and BAKER, 1956) are conditions which have been known to predispose to the development of mucormycosis. In lower animals, however, the association of natural infection with an altered physiological state has not been demonstrated. To date, several species in the genera Mucor, Rhizopus and Absidia have been incriminated in spontaneous mucormycosis in animals. Members of these three genera are commonly encountered in the laboratory as contaminants. Thus, the mere recovery of phycomycetes from clinical materials does not furnish sufficient proof of their incrimination in a disease process. To establish a diagnosis of mucormycosis, it is essential to demonstrate tissue invasion in addition to recovery of the causal agent. In tissues, members of the genera Mucor, Rhizopus, and Absidia develop broad (6--15 #) branched, non-septate mycelium. In culture they are characterized by the formation of similar mycelium and production of asexual sporangiospores and, in some cases, by the development of sexual spores that are termed zygospores.

Fatal aspergillosis in imported parrots

Spontaneous fatal aspergillosis occurred in several species of parrots imported from Latin America, Australia, Malaya and Ghana for studies on the control of psittacosis. Over a period of 4 years, 655 parrots were imported for use in these studies. All birds that died during these investigations were necropsied, and the internal organs of 45 were found to have macroscopic lesions suggestive of aspergillosis. Of these 45 suspected cases, 32 were confirmed as aspergillosis by both histopathology and culture, and three others by histopathology alone. There was no evidence that the remaining 10 had this disease. Of the 32 culturally confirmed cases, 13 were found to be caused by Aspergillus fumigatus, 16 by A. oryzae, and three by both fungi. In this series, three sets of circumstances appear to have been associated with the development of fatal aspergillosis. Their capture and transport to the United States, the administration of chlortetracycline used in the control of psittacosis, and the administration of cortisone acetate in an attempt to activate existent latent psittacosis infections. The possible causal relationship of these factors are discussed.

Exogenous Corneal Ulcer Caused by Tritirachium Roseum

A 29-year-old white man developed a corneal ulcer following trauma to his left cornea by a piece of wire. Tritirachium roseum, a saprophytic fungus, was cultured from corneal scrapings and demonstrated in the corneal button by histopathologic examination.

Antigenic relationships between Aracoccidioides loboi and other pathogenic fungi determined by immunofluorescence

The fluorescent antibody technique was used to study antigenic relationships betweenParacoccidioides loboi and other pathogenic fungi. The findings suggest thatP. loboi is more closely related antigenically to certainP. brasiliensis strains than to others and that it has antigens in common with the yeast form ofHistoplasma capsulatum, H. duboisii, Blastomyces dermatitidis, Candida albicans and also the mycelial form ofCoccidioides immitis. Serum globulins from 3 cases of keloidal blastomycosis were labelled with fluorescein isothiocyanate. These conjugates showed slight or no reactivity withP. loboi, the yeast forms ofP. brasiliensis, H. capsulatum, H. duboisii andB. dermatitidis, However, they stained brightlyC. albicans, serotypes A and B, the tissue form ofC. immitis and the yeast form ofSporotrichum schenckii. Adsorption of these reagents withC. albicans eliminated all staining except that forS. schenckii. These patients had no history of clinical sporotrichosis.

The development and evaluation of immunodiffusion, immunofluorescence and physiological tests for the differentiation of atypical Trichophyton rubrum and T. mentagrophytes isolates.

Five laboratory procedures: 1) immunodiffusion, 2) immunofluorescence, 3) in vitro hair perforation, 4) pigment stimulation, and 5) a urease test were compared for their ability to differentiateT. rubrum fromT. mentagrophytes. Of the physiological tests, thein vitro hair perforation technique was the most reliable for differentiating the two species. With the serological tests, the organisms were not differentiated by immunodiffusion, but if appropriate dilutions of the conjugates were used in immunofluorescence testing, most isolates could be differentiated.