Sinusitis caused by Legionella pneumophila in a patient with the acquired immune deficiency syndrome.

A patient with the acquired immune deficiency syndrome and Legionella pneumophila infection of the maxillary sinus is described. The organism was identified by direct immunofluorescence staining of sinus tissue. Because the Legionella species are intracellular pathogens, it is not surprising that this patient with a cellular immune defect was infected. However, no other site of Legionella infection was found. This appears to be the first reported case of upper respiratory tract infection by a Legionella species.

Lyme carditis. Electrophysiologic and histopathologic study.

To further define the nature of Lyme carditis, electrophysiologic study and endomyocardial biopsy were performed in a patient with Lyme disease, whose principal cardiac manifestation was high-degree atrioventricular block. Intracardiac recording demonstrated supra-Hisian block and complete absence of an escape mechanism. Gallium 67 scanning demonstrated myocardial uptake, and right ventricular endomyocardial biopsy revealed active lymphocytic myocarditis. A structure compatible with a spirochetal organism was demonstrated in one biopsy specimen. It is concluded that Lyme disease can produce active myocarditis, as suggested by gallium 67 imaging and confirmed by endomyocardial biopsy. Furthermore, the presence of high-grade atrioventricular block in this disease requires aggressive management with temporary pacemaker and corticosteroid therapy.

Pneumocystis carinii pneumonitis. The nature and diagnostic significance of the methenamine silver-positive "intracystic bodies".

The cyst forms of Pneumocystis carinii in specimens stained with methenamine silver contain single or paired discrete foci of enhanced staining that measure 1-2 micron in maximum size. The nature of these foci and their location within the cysts have been disputed. We demonstrate by electron microscopy of silver-stained sections that the darkly stained foci correspond to a focal thickening of the cyst wall and are unrelated to sporozoites and other intracystic organelles. The morphology of these structures by light microscopy is characteristic, and their recognition is helpful in identifying P. carinii cysts and in differentiating them from yeast-form fungi and argyrophilic tissue elements in histologic sections and cytology specimens.

Pseudomicrobes: some potential diagnostic pitfalls in the histopathologic assessment of inflammatory lesions.

In the histopathologic evaluation of inflammatory lesions, numerous structures suggestive but not representative of microbial agents are encountered and may lead to erroneous diagnoses. Examples of pseudomicrobes are illustrated and discussed to prevent potential incorrect histopathologic assessments.

Staining qualities of cytomegalovirus inclusions in the lungs of patients with the acquired immunodeficiency syndrome: a potential source of diagnostic misinterpretation.

Gomori's methenamine silver and the periodic acid--Schiff reaction stain cytoplasmic but not intranuclear cytomegalovirus inclusions. The biochemical basis of these staining qualities is discussed, and the staining characteristics are correlated with supporting ultrastructural observations. Failure to recognize this phenomenon may lead to erroneous diagnostic conclusions at the light microscopic level.

Chlamydia trachomatis in chronic abacterial prostatitis: demonstration by colorimetric in situ hybridization.

Twenty-three transurethral resected prostate specimens with histologic evidence of chronic abacterial prostatitis were evaluated by colorimetric in situ hybridization for evidence of Chlamydia trachomatis. Intracellular chlamydia bodies were detected in seven of 23 cases (30.4%). In five of seven positive cases, chlamydia inclusion bodies were present within both epithelial cells and intraluminal histiocytes. In two of seven positive cases, extracellular chlamydia bodies were identified in conjunction with intraepithelial inclusions. In only one case were extraductal, extraacinar, intrahistiocytic inclusion bodies observed. Our study confirms previous reports implicating C trachomatis as an etiologic agent in chronic abacterial prostatitis, and underscores the applicability of DNA probes for the detection and identification of C trachomatis in routinely fixed, paraffin-embedded tissues.

Rapid demonstration of Legionella pneumophila in unembedded tissue. An adaptation of the Giménez stain.

The Giménez stain, originally developed for demonstrating rickettsiae, readily stained the Legionnaires' disease bacterium (Legionella pneumophila) in frozen tissue sections and smears of fresh or formalin-fixed lung tissue from patients who had confirmed Legionnaires' disease. With the Giménez procedure, the bacterium stained bright red against a blue-green background. The tissue Gram procedures also stained L. pneumophila in frozen sections and smears, but the staining reaction was weak, and these stains were neither as sensitive nor a consistent as the Giménez procedure.

Pathogenesis of acute Legionnaires' disease pneumonia.

Immunofluorescent study of the lungs in cases of fatal suspected acute Legionnaires' disease enabled confirmation of the presence of Legionella pneumophila. In addition, probable pathogenetic mechanisms that had not been as clearly visualized by light microscopy became apparent: the retrograde involvement of the larger bronchioles and proximal airways, invasion of the interstitium, extension to pleura, and lymphatic and hematogenous spread. Organisms were demonstrated to occur in the liver and spleen of one patient. The development of technics for the earliest possible diagnostic verification of Legionnaires' disease, with specimens obtained as untraumatically as practical from selected sites and screened by specific immunofluorescent microscopic examination, should contribute to patient survival.

Green algal infection in a human.

Infection by unicellular green algae has not been described in humans. A case is reported in a 30-year-old woman who developed persistent infection of a healing operative wound on the dorsum of the right foot, after possible contamination by river water while canoeing. The wound was debrided 2 months later. Histologically, infected tissues contained mixed suppurative and granulomatous inflammation associated with endosporulating, round to oval microorganisms, ranging from 6-9 microns in diameter. Many of these organisms contained multiple, strongly periodic acid-Schiff, Gomori methenamine-silver, and Gridley fungus-positive granules in the cytoplasm. The organisms in tissue did not stain with fluorescent antibody conjugates specific for the two known pathogenic Prototheca species. In some organisms, electron microscopy revealed membranous cytoplasmic profiles considered to be remnants of degenerated chloroplasts. These findings are consistent with the presence of a green algal infection.

Ultrastructure of the agent of Legionnaires' disease in the human lung.

This report confirms the gram-negative ultrastructural characteristics of the Legionnaires' disease organism by direct examination of pulmonary tissue from six confirmed cases--two from the original Philadelphia epidemic of 1976 and four from more recent sporadic cases. All microorganisms seen in all six lungs were identical ultrastructurally and were predominantely within intra-alveolar macrophages, as previously observed by light microscopy. They appeared as short, blunt rods that were clearly prokaryotic; i.e., they had diffuse electron-lucent nucleoid areas interspersed among areas of well-defined ribosomes, a pinching nonseptic division, and enclosure within a double envelope consisting of two three-layer "unit" membranes, each approximately 75 A wide. This structure, together with a pinching division, is typical of gram-negative bacteria. The Legionnaires' disease organism multiples both intracellularly and extracellularly in tissue and has no unique ultrastructural features that would aid in its specific identification. These findings are compared with recent reports describing the ultrastructure of what was considered to be the Legionnaires' disease organism in yolk sac and culture medium, and in one human lung.

Giant forms of Blastomyces dermatitidis in the pulmonary lesions of blastomycosis. Potential confusion with Coccidioides immitis.

Typical yeast-phase cells of Blastomyces dermatitidis have a characteristic appearance in tissue sections. Fungal morphologic variation occurs infrequently in the lesions of blastomycosis, yet it can complicate the differential diagnosis, particularly if fresh tissue is not available for microbiologic culture. The authors report a case of pulmonary blastomycosis, confirmed by culture and direct immunofluorescence, in which some of the yeast-like cells were abnormally large. These giant yeast-like cells exceeded the size range accepted for the tissue forms of B. dermatitidis; therefore, coccidioidomycosis was considered initially in the differential diagnosis. Otherwise characteristic morphologic features of these cells, in particular multinucleation and the production of broad-based blastoconidia, helped resolve the differential diagnosis. The diagnosis can be confirmed by direct immunofluorescence or microbiologic culture.

Zygomycosis. Report of four cases with formation of chlamydoconidia in tissue.

The authors describe spheric to ovoid chlamydoconidia and mucoraceous hyphae in tissues from four patients, two with cutaneous and two with pulmonary zygomycosis. The diagnosis in each case was confirmed by immunofluorescence staining and the presence of characteristic hyphae in tissue. It is important that these conidia be recognized, because they can easily be mistaken for other fungi, nematode ova, or other microorganisms in tissue sections, thereby resulting in the potential for misdiagnosis.

Acremonium recifei as an agent of mycetoma in India.

Acremonium recifei was identified as the causal agent in a case of white grain eumycotic mycetoma of the hand which occurred in South India. The identification was based on the structure of the granules in tissue and on the morphological characteristics of the culture obtained from the granules. This case represents the first documented instance in which A. recifei has been found outside of Latin America.

Disseminated unicellular green algal infection in two sheep in India.

Unicellular green algae infected and disseminated in two adult Nellore brown rams in India. At necropsy multiple green lesions were observed in the lungs, liver and kidneys of both sheep. Histological examination revealed necrotizing granulomas that contained numerous spheroidal to elliptical organisms ranging from 5-20 micrometers in diameter. These organisms occurred in several reproductive stages: small (5-9 micrometers) single, undifferentiated cells; intermediate (9-15 micrometers) cells undergoing nuclear and cytoplasmic cleavage; and large, mature, endosporulating cells containing two to six or more endospores. In addition, occasional large (20-35 micrometers), round thick-walled forms were among the typical cells. The cytoplasm of the algal cells contained numerous, large, irregularly-shaped and densely packed granules of varying sizes, which were strongly stained by the Gridley fungus, periodic acid-Schiff, and Gomori methenamine silver procedures. Electron microscopic studies revealed chloroplasts in the cytoplasm of these organisms. The chloroplasts consisted of smoothly contoured electron-lucent or electron-dense granules, 0.5 to 3.0 micrometers in diameter, that were either surrounded by or contiguous to two or more tightly appressed membranes or multidisc bands. Some of the alternating membranes appeared to be spirally twisted or associated with several cytoplasmic granules in one plane of section. This is the first record of algal infections in India.

Acquired immunity in B cell-deficient mice to challenge exposure following primary infection with Schistosoma mansoni.

Mice were made B cell-deficient by injections of globulin prepared from goat antimouse mu-chain serum. Anti-mu globulin was administered throughout the experiments (18 or 23 weeks). B cell deficiency was determined at the time of assay of worm burden levels (7 weeks after challenge with Schistosoma mansoni) by quantitation of serum IgM and IgG, by assaying the specific antibody response to cercarial and adult worm antigens in enzyme-linked immunosorbent assay and by histologic examination of the spleen and mesenteric (regional) lymph nodes. Four-week-old mice were exposed to S. mansoni and 8 weeks later were challenged with a second exposure. The B cell-deficient mice developed a degree of resistance (79%) similar to that of the intact controls (81%). The IgM and IgG levels of the B cell-deficient mice were markedly suppressed. Follicular development was not detected in their lymph nodes; but in the spleen of some animals clusters of cells morphologically similar to B cells were observed peripheral to a central T cell-like area. B cell-deficient mice developed schistosome egg granulomas comparable to those of the intact controls. Control animals developed an antibody response with titers of 1:64 to 1:1,024 against cercarial and adult worm antigens; B cell-deficient animals were nonreactive in these assays. The data suggest that specific antibody does not play a major role in resistance acquired within 8 weeks as a result of a primary infection in murine schistosomiasis.

Schistosoma mansoni infection in intact and B cell deficient mice: the effect of pretreatment with BCG in these experimental models.

The course of infection with Schistosoma mansoni was determined in B cell deficient mice by means of a schistosomule lung recovery assay 6 days after infection or by determination of the adult worm burden 7 weeks after infection. The intensity of infection was not significantly different from that in age- and sex-matched intact controls. B cell deficiency was demonstrated by absence of surface immunoglobulin-bearing cells in the spleen and by absence of B cell areas in the lymphoid follicles of the spleen and mesenteric lymph nodes. In addition, B cell deficient mice infected for 7 weeks with S. Mansoni were unable to form anti-schistosome antibodies detectable by the Cercarienhüllenreaktion. A normal granulomatous response, however, was observed around schistosome eggs. Pretreatment with BCG suppressed infection with S. mansoni comparably in intact and B cell deficient mice. A marked depletion of eosinophils occurred in the schistosome egg granuloma of all BCG treated mice.

Characterization of Fort Morgan virus, an alphavirus of the western equine encephalitis virus complex in an unusual ecosystem.

An alphavirus isolated from nestling Cliff Swallows (Petrochelidon pyrrhonota) and House Sparrows (Passer domesticus) and from cimicid bugs (Oeciacus vicarius) in eastern Colorado, for which we propose the name Fort Morgan (FM) virus, is sensitive to the action of sodium deoxycholate, unstable at pH 2.0-4.0, and demonstrates no characteristics of temperature-sensitive mutants. Unpassaged field strains are nonpathogenic, or of low pathogenicity, for suckling mice; however, plaque-purified FM virus is pathogenic for a variety of laboratory hosts. By hemagglutination-inhibition (HI), complement-fixation, and neutralization tests, cross-reactions were observed between FM virus and members of the western equine encephalitis (WEE) virus antigenic complex. Short-incubation HI tests indicated that the new isolate shared closer antigenic relationships with WEE complex virus strains from the eastern United States (Highlands J virus) than with other WEE complex viruses. On the basis of these serological findings, as well as characterization of the structural polypeptides and oligonucleotides, we suggest that FM is a distinct virus belonging to the WEE antigenic complex. A reconsideration of the taxonomy of the WEE complex and discussion of the epizoologic significance of FM virus are presented.

Phaeohyphomycosis in El Salvador caused by Exophiala spinifera.

We identified Exophiala spinifera as the causal agent in a case of subcutaneous phaeohyphomycosis in El Salvador. Identification was based on the morphology of the fungus in tissue and the microscopic features of the culture obtained from the biopsy material. This case is the first of this type to be documented from Central America.

Gross and histological studies of immediate, Arthus, and delayed skin test responses to schistosome antigen, and of delayed response to ubiquitous antigens in Egyptians.

Gross studies of skin reactions to adult antigen of Schistosoma mansoni were made on 156 hospitalized patients with schistosomiasis and 114 subjects from the nonendemic area of Hurghada in Egypt. Wheal areas equal to or greater than 1.0 cm2 indicated a positive immediate (15-min) reaction to adult worm antigen; the criterion of positivity for both 24-hour and 48-hour delayed reactions was an area of induration equal to or greater than 0.6 cm2. Immediate reactions with adult worm antigen were observed in 99% of the patients with schistosomiasis and 11% of the subjects from Hurghada: the percentages with delayed reaction were 58% and 2%, respectively. Biopsies of skin test sites at various intervals after antigen injection were done on 87 individuals. Eosinophilic and mononuclear infiltrates were characteristic of immediate and delayed skin responses, respectively. Biopsies from 22 patients with marked skin reactions 5 hours after antigen injection showed that a neutrophilic response indicative of Arthus reactivity was present in only 18. Thus, Arthus reactivity could not be determined on gross appearance alone. The studies did not show any evidence of delayed basophilic hypersensitivity to schistosome antigen. Immunofluorescent studies on a small number of biopsies suggested that a late phase (5-hour) reaction due to IgE may occur in some patients. Delayed reactivity to mumps and/or monilia skin test antigens was observed in 91% of Egyptians in a nonendemic area of schistosomiasis. Delayed hypersensitivity to PPD was detected in 44% of the same group.

First case of subcutaneous zygomycosis caused by Saksenaea vasiformis in India.

The first case of subcutaneous zygomycotic infection caused by Saksenaea vasiformis in a rice mill worker from India is described. The infection, confined to the man's left foot, showed multiple draining sinuses, inflammation, and intermittent low-grade fever following a crushing injury when a log fell on his foot. Histopathologic examination of two biopsy specimens, taken at 3-wk intervals, revealed the presence of broad, sparsely septate, branched, hyaline hyphae characteristic of a zygomycete. When they were grown on a nutritionally deficient medium, two cultures isolated from the biopsied tissues formed numerous, vase-shaped sporangia typical of S. vasiformis. Necrosis of the affected area led to amputation of the fore part of the foot. A split thickness graft was well accepted, and treatment with potassium iodide, following the graft, cured the infection.