Vet. Pathol. 14: 387-391 (1977)
Paecilomycosis in a Nonhuman Primate (Macaca mulatta) R. W.
FLEISCHMAN
and D.
MCCRACKEN
Department of Pathology, Mason Research Institute, Inc., Worcester, Mass.
Abstract. Focal granulomas caused by fungi in the genus Paecilomyces occurred at subcutaneous and laryngeal sites in a Rhesus monkey. Slight wheezing was noted 8 months before the monkey died. Death was unexpected and was caused by asphyxiation after occlusion of the larynx by a fungal granuloma.
We necropsied a Rhesus monkey that died unexpectedly while being used in a reproductive physiology study. This paper which describes the clinical and pathological findings of Paecilomycosis, is believed to be the first report of this mycotic infection in a nonhuman primate. Case History Our Rhesus monkey (Macaca mulatta) , a 4-year-old female, probably came from northeastern India and arrived in a shipment from a commercial supplier in July 1973. Tuberculin tests on arrival and at 3-month intervals thereafter were negative. About 2 months after arrival, the monkey was ovariectomized for a series of estrogen bioassays. For a year the monkey was given a series of five 10-day oral treatments with unknown estrogenic compounds. Near the end of the treatment period a slight wheezing respiration was noted. The respiratory signs became more severe until the monkey died 8 months later. In the early weeks breathing was labored only when the monkey was nervous. During the last days before death the monkey made a groaning sound when breathing in and out. About 16 months after treatment began there was a firm, oval, freely movable, 20x20x6 millimeters, subcutaneous nodule over the right scapula. The skin over the mass was hairless with patchy erosions. Three months later a similar nodule, 5x6x3 millimeters, was found on the right thigh. A chest radiograph and tuberculin test the next day were negative. A day later one nodule was removed for histological diagnosis and 4 days later the monkey died. The monkey's appetite had been good except for the last 2 weeks when she ate less. The monkey died unexpectedly a few hours after eating normally. 387
388
Fleischman and McCracken
Materials and Methods Skin lesions removed 3 days before the monkey died were fixed in 10 percent buffered formalin, embedded in paraffin, sectioned at 5-6 micrometers, and strained with hematoxylin and eosin (HE). The monkey was necropsied soon after death and tissues were fixed and processed as above. Selected tissues were stained with Brown and Brenn, Grocott's methenamine silver, Ziehl-Neelsen acid fast, periodic acid-Schiff (PAS), mucicarmine and May-Griinwald Giemsa.
Results
The monkey was thin but well developed. All body openings, eyes, skin and coat were normal. All teeth except the last molars had erupted. Visible and palpable in the subcutaneous tissues near the right scapula was a 20x20x6 millimeter, firm, oval mass. The skin over the mass was tight, hairless and eroded over 10 percent of the surface. On section, the mass was slightly granular, uniform and gray-tan. In the mid lateral region of the right thigh was a 25-millimeter sutured incision. Body cavities and serosal surfaces were free of hemorrhages, effusions and adhesions. The lungs were diffusely distended, moderately crepitant and did not collapse when the thorax was opened. The size of the larynx was not changed, however, the laryngeal passageway was almost occluded near the thyroid and cricoid cartilages by an ovoid mass of gray-tan tissue (fig. 1) that originated immediately behind the left vocal fold. The mass was 11x7x5 millimeters and had a texture, density and color similar to the subcutaneous masses found at the right scapula and left thigh. The tracheobronchial tree was dry except for slight edema in the main stem bronchi. The ovaries were absent having been removed 13/4 years previously. Significant microscopic changes were limited to the nodules in the subcutaneous tissues near the right scapula, right thigh and larynx. The histologic pattern at each site was essentially the same and was characterized by granulomatous inflammation with sheets and nodules mainly of reticuloendothelial cells separated by mature connective tissue (fig. 2). There were many Langhans' and foreign-body giant cells. Fungal hyphae, conidia and spores were primarily within the cytoplasm of epithelioid and giant cells. The fungi could be seen with HE, Giemsa and mucicarmine but were best demonstrated with PAS and Grocott methenamine-silver. The short septate hyphae seemed compartmentalized by pleomorphic vesicles and swellings (fig. 3). Occasionally vacuolated oval conidia were seen at the end of the mycelia. More often pleomorphic conidia were without associated mycelia and were surrounded by a small artefactual space. The fungi were negative with acid-fast and Brown and Brenn stains. Other inflammatory cells randomly distributed throughout the mass were polymorphonuclear leucocytes, eosinophils, plasma cells and lymphocytes. The lymphocytes sometimes formed small aggregates in the connective tissue stroma and adjacent skeletal muscle bundles. Necrosis was absent throughout the nodules except where minor superficial erosion and acute inflammation occurred over the skin masses.
Simian Paecilomycosis
389
Fig 1: Postero-anterior view (lower specimen) of open larynx with epiglottis (e), divided arytenoid cartilages (a) and vocal folds (v). Lesion arises caudal to left vocal fold. Transverse section (upper specimen) through the esophagus and larynx, 7 millimeters posterior to the vocal folds. Lesion occludes the lumen of the larynx.
The morphologic features of the tissue phase of the fungal agent are compatible with those of genus Paecilomyces, most probably P. varioti. Discussion The unusual location of the paecilomyces fungal granuloma within the larynx of the monkey led to its respiratory difficulty and death from asphyxiation. The failure of the lungs to collapse after the chest was opened suggests the laryngeal nodule acted as a valve and interfered with normal expiration and probably inspiration. The pathogenesis of this fungal infection is unknown; however, subcutaneous and laryngeal localization may have come after unrecognized trauma. It is unlikely that the infection was blood-borne because there was no visceral involvement and because the distribution of the lesions was unrelated. The wheezing of the monkey 7 months before death suggests there were laryngeal lesions without skin involvement. There were no predisposing causes for an increased incidence of mycotic disease such as a long and debilitating illness or prolonged use of immunosuppressive drugs or antibiotics. Paecilomyces has been associated with spoiled canned fruits [10]. Fresh fruit was fed to the monkey three times a week.
390
Fleischman and McCracken
3
2 Fig 2: Intracytoplasmic Paecilomyces (arrows) within multinucleated giant cells. PAS. Fig 3: Septate hyphae and conidia of Paecilomyces. Grocott's methenamine silver.
The genus Paecilomyces was first described in 1907 by Bainier as a saprophytic mold related to Penicillium and Aspergillus that is never green [1]. Paecilomyces are found world wide and are believed to be airborne nonpathogenic common laboratory contaminants [13]. Nevertheless, a few naturally occurring human and animal infections have been reported. In man, Paecilomyces was isolated from lesions of endocarditis occurring after cardiac surgery [4, 8, 13, 14] and from a single case of posttraumatic endophthalmitis [12]. During the past 15 years fungal endocarditis has increased in incidence because of the greater occurrence of cardiac surgery and the increase in the number of narcotic addicts using nonsterile intravenous techniques [5]. Deep mycoses caused by Paecilomyces have been reported in horse [3), tortoise [2] and dog [6, 7,9]. Experimental infections with this fungus have been studied in guinea pigs, rabbits, mice, rats, pigeons and chickens [11] and the action of its mycotoxin has been tested in embryonated eggs, ducklings and rabbits [4]. Acknowledgements We thank Dr. Alexander De Paoli and consultants in Geographic Pathology at the Armed Forces Institute of Pathology and mycologists at the National Institutes of Health for diagnosis and Dr. Molinari for translating Italian manuscripts. Supported by contract NOI-HD-2-2746, Contraceptive Development Branch, National Institute of Child Health and Development.
References Brown, A. H. S.; Smith, G.: The genus Paecilomyces Bainier and its perfect stage Byssochlamys Westling. Trans Br Mycol Soc 40: 17, 1957
Simian Paecilomycosis
391
2 Georg, L. K.; Williamson, W. M.; Tilden, E. B.; Getty, R. E.: Mycotic pulmonary disease of captive giant tortoises due to Beauvaria bassiana and Paecilomycesfumoso roseus. Sabouraudia 2: 80-86,1962 3 Gaullini, L.; Mandelli, G.: Osservazioni sull'azione patogena sperimentale di Paeeilomyces varioti Bainter 1907. Atti Soc Ital Sci Vet 21: 832-834, 1967 4 Gaullini, L.: Sulla caratterizzazione biologica dell'attivita micotossica di un ceppo diPaeciiomyces variotiBainier 1907. Clin Vet Milano 91: 7-15,1968 5 Haldane, E. V.; MacDonald, J. L.; Gittens, W.O.; Yuce, K.; Rooyen, C. E. van: Prosthetic valvular endocarditis due to the fungus' Paecilomyces. Can Med Assoc J III: 963-968, 1974 6 Hoven, E. van den: SuspectedPaeciiomyces in a dog. Aust Vet J 50: 363-367,1974 7 Jang, S. S.; Biberstein, E. L.; Slauson, D.O.; Suter, P. F.: Paecilomycosis in a dog. J Am Vet Med Assoc 159: 1775-1779, 1971 8 McClellan, J. R.; Hamilton, J. D.; Alexander, J. A.; Wolfe, W. G.; Reed, J. B.: Paecilomyces varioti endocarditis on a prosthetic aortic valve. J Thorac Cardiovasc Surg 71: 472-475, 1976 9 Patnaik, A. K.; Si-Kwang, L.; Wilkins, R. J.; Johnson, G. F.; Seitz, P. E.: Paecilomycosis in a dog. J Am Vet Med Assoc 161: 806-813, 1972 10 Raper, K. B.; Thorn, C.: A manual of Penicillia, p. 688; Williams and Wilkins, Baltimore, 1949 11 Redaelli, G.; Guallini, L.; Mandelli, G.: Osservazioni sull'azione patogena sperimentale di (Paeeilomyces variotiBainier; 1907). Arch Vet Ita119: 185-198, 1968 12 Rodrigues, M. M.; MacLeod, D.: Exogenous fungal endophthalmitis caused by Paecilomyees. Am J Opthalmol 79: 687-690, 1975 13 Silver, M. D.; Tuffnell, P. G.; Bigelow, W. G.: Endocarditis caused by Paecilomyces varioti affecting an aortic valve allograft. J Thorac Cardiovasc Surg 61: 278-281, 1971 14 Uys, C. J .; Don, P. A.; Schrire, V.; Barnard, C. N.: Endocarditis following cardiac surgery due to the fungusPaeciiomyces. S Afr Med J 37: 1276-1280, 1963 15 Wolf, P. L.; Russell, B.; Shimoda, A.: Practical clinical microbiology and mycology techniques and interpretations, pp. 429-530; John Wiley and Sons, New York, 1975
Request reprints from Dr. Robert W. Fleischman, Department of Pathology, Mason Research Institute, Worcester, MA 01608 (USA).
Paecilomycosis in a Nonhuman Primate (Macaca mulatta) R. W.
FLEISCHMAN
and D.
MCCRACKEN
Department of Pathology, Mason Research Institute, Inc., Worcester, Mass.
Abstract. Focal granulomas caused by fungi in the genus Paecilomyces occurred at subcutaneous and laryngeal sites in a Rhesus monkey. Slight wheezing was noted 8 months before the monkey died. Death was unexpected and was caused by asphyxiation after occlusion of the larynx by a fungal granuloma.
We necropsied a Rhesus monkey that died unexpectedly while being used in a reproductive physiology study. This paper which describes the clinical and pathological findings of Paecilomycosis, is believed to be the first report of this mycotic infection in a nonhuman primate. Case History Our Rhesus monkey (Macaca mulatta) , a 4-year-old female, probably came from northeastern India and arrived in a shipment from a commercial supplier in July 1973. Tuberculin tests on arrival and at 3-month intervals thereafter were negative. About 2 months after arrival, the monkey was ovariectomized for a series of estrogen bioassays. For a year the monkey was given a series of five 10-day oral treatments with unknown estrogenic compounds. Near the end of the treatment period a slight wheezing respiration was noted. The respiratory signs became more severe until the monkey died 8 months later. In the early weeks breathing was labored only when the monkey was nervous. During the last days before death the monkey made a groaning sound when breathing in and out. About 16 months after treatment began there was a firm, oval, freely movable, 20x20x6 millimeters, subcutaneous nodule over the right scapula. The skin over the mass was hairless with patchy erosions. Three months later a similar nodule, 5x6x3 millimeters, was found on the right thigh. A chest radiograph and tuberculin test the next day were negative. A day later one nodule was removed for histological diagnosis and 4 days later the monkey died. The monkey's appetite had been good except for the last 2 weeks when she ate less. The monkey died unexpectedly a few hours after eating normally. 387
388
Fleischman and McCracken
Materials and Methods Skin lesions removed 3 days before the monkey died were fixed in 10 percent buffered formalin, embedded in paraffin, sectioned at 5-6 micrometers, and strained with hematoxylin and eosin (HE). The monkey was necropsied soon after death and tissues were fixed and processed as above. Selected tissues were stained with Brown and Brenn, Grocott's methenamine silver, Ziehl-Neelsen acid fast, periodic acid-Schiff (PAS), mucicarmine and May-Griinwald Giemsa.
Results
The monkey was thin but well developed. All body openings, eyes, skin and coat were normal. All teeth except the last molars had erupted. Visible and palpable in the subcutaneous tissues near the right scapula was a 20x20x6 millimeter, firm, oval mass. The skin over the mass was tight, hairless and eroded over 10 percent of the surface. On section, the mass was slightly granular, uniform and gray-tan. In the mid lateral region of the right thigh was a 25-millimeter sutured incision. Body cavities and serosal surfaces were free of hemorrhages, effusions and adhesions. The lungs were diffusely distended, moderately crepitant and did not collapse when the thorax was opened. The size of the larynx was not changed, however, the laryngeal passageway was almost occluded near the thyroid and cricoid cartilages by an ovoid mass of gray-tan tissue (fig. 1) that originated immediately behind the left vocal fold. The mass was 11x7x5 millimeters and had a texture, density and color similar to the subcutaneous masses found at the right scapula and left thigh. The tracheobronchial tree was dry except for slight edema in the main stem bronchi. The ovaries were absent having been removed 13/4 years previously. Significant microscopic changes were limited to the nodules in the subcutaneous tissues near the right scapula, right thigh and larynx. The histologic pattern at each site was essentially the same and was characterized by granulomatous inflammation with sheets and nodules mainly of reticuloendothelial cells separated by mature connective tissue (fig. 2). There were many Langhans' and foreign-body giant cells. Fungal hyphae, conidia and spores were primarily within the cytoplasm of epithelioid and giant cells. The fungi could be seen with HE, Giemsa and mucicarmine but were best demonstrated with PAS and Grocott methenamine-silver. The short septate hyphae seemed compartmentalized by pleomorphic vesicles and swellings (fig. 3). Occasionally vacuolated oval conidia were seen at the end of the mycelia. More often pleomorphic conidia were without associated mycelia and were surrounded by a small artefactual space. The fungi were negative with acid-fast and Brown and Brenn stains. Other inflammatory cells randomly distributed throughout the mass were polymorphonuclear leucocytes, eosinophils, plasma cells and lymphocytes. The lymphocytes sometimes formed small aggregates in the connective tissue stroma and adjacent skeletal muscle bundles. Necrosis was absent throughout the nodules except where minor superficial erosion and acute inflammation occurred over the skin masses.
Simian Paecilomycosis
389
Fig 1: Postero-anterior view (lower specimen) of open larynx with epiglottis (e), divided arytenoid cartilages (a) and vocal folds (v). Lesion arises caudal to left vocal fold. Transverse section (upper specimen) through the esophagus and larynx, 7 millimeters posterior to the vocal folds. Lesion occludes the lumen of the larynx.
The morphologic features of the tissue phase of the fungal agent are compatible with those of genus Paecilomyces, most probably P. varioti. Discussion The unusual location of the paecilomyces fungal granuloma within the larynx of the monkey led to its respiratory difficulty and death from asphyxiation. The failure of the lungs to collapse after the chest was opened suggests the laryngeal nodule acted as a valve and interfered with normal expiration and probably inspiration. The pathogenesis of this fungal infection is unknown; however, subcutaneous and laryngeal localization may have come after unrecognized trauma. It is unlikely that the infection was blood-borne because there was no visceral involvement and because the distribution of the lesions was unrelated. The wheezing of the monkey 7 months before death suggests there were laryngeal lesions without skin involvement. There were no predisposing causes for an increased incidence of mycotic disease such as a long and debilitating illness or prolonged use of immunosuppressive drugs or antibiotics. Paecilomyces has been associated with spoiled canned fruits [10]. Fresh fruit was fed to the monkey three times a week.
390
Fleischman and McCracken
3
2 Fig 2: Intracytoplasmic Paecilomyces (arrows) within multinucleated giant cells. PAS. Fig 3: Septate hyphae and conidia of Paecilomyces. Grocott's methenamine silver.
The genus Paecilomyces was first described in 1907 by Bainier as a saprophytic mold related to Penicillium and Aspergillus that is never green [1]. Paecilomyces are found world wide and are believed to be airborne nonpathogenic common laboratory contaminants [13]. Nevertheless, a few naturally occurring human and animal infections have been reported. In man, Paecilomyces was isolated from lesions of endocarditis occurring after cardiac surgery [4, 8, 13, 14] and from a single case of posttraumatic endophthalmitis [12]. During the past 15 years fungal endocarditis has increased in incidence because of the greater occurrence of cardiac surgery and the increase in the number of narcotic addicts using nonsterile intravenous techniques [5]. Deep mycoses caused by Paecilomyces have been reported in horse [3), tortoise [2] and dog [6, 7,9]. Experimental infections with this fungus have been studied in guinea pigs, rabbits, mice, rats, pigeons and chickens [11] and the action of its mycotoxin has been tested in embryonated eggs, ducklings and rabbits [4]. Acknowledgements We thank Dr. Alexander De Paoli and consultants in Geographic Pathology at the Armed Forces Institute of Pathology and mycologists at the National Institutes of Health for diagnosis and Dr. Molinari for translating Italian manuscripts. Supported by contract NOI-HD-2-2746, Contraceptive Development Branch, National Institute of Child Health and Development.
References Brown, A. H. S.; Smith, G.: The genus Paecilomyces Bainier and its perfect stage Byssochlamys Westling. Trans Br Mycol Soc 40: 17, 1957
Simian Paecilomycosis
391
2 Georg, L. K.; Williamson, W. M.; Tilden, E. B.; Getty, R. E.: Mycotic pulmonary disease of captive giant tortoises due to Beauvaria bassiana and Paecilomycesfumoso roseus. Sabouraudia 2: 80-86,1962 3 Gaullini, L.; Mandelli, G.: Osservazioni sull'azione patogena sperimentale di Paeeilomyces varioti Bainter 1907. Atti Soc Ital Sci Vet 21: 832-834, 1967 4 Gaullini, L.: Sulla caratterizzazione biologica dell'attivita micotossica di un ceppo diPaeciiomyces variotiBainier 1907. Clin Vet Milano 91: 7-15,1968 5 Haldane, E. V.; MacDonald, J. L.; Gittens, W.O.; Yuce, K.; Rooyen, C. E. van: Prosthetic valvular endocarditis due to the fungus' Paecilomyces. Can Med Assoc J III: 963-968, 1974 6 Hoven, E. van den: SuspectedPaeciiomyces in a dog. Aust Vet J 50: 363-367,1974 7 Jang, S. S.; Biberstein, E. L.; Slauson, D.O.; Suter, P. F.: Paecilomycosis in a dog. J Am Vet Med Assoc 159: 1775-1779, 1971 8 McClellan, J. R.; Hamilton, J. D.; Alexander, J. A.; Wolfe, W. G.; Reed, J. B.: Paecilomyces varioti endocarditis on a prosthetic aortic valve. J Thorac Cardiovasc Surg 71: 472-475, 1976 9 Patnaik, A. K.; Si-Kwang, L.; Wilkins, R. J.; Johnson, G. F.; Seitz, P. E.: Paecilomycosis in a dog. J Am Vet Med Assoc 161: 806-813, 1972 10 Raper, K. B.; Thorn, C.: A manual of Penicillia, p. 688; Williams and Wilkins, Baltimore, 1949 11 Redaelli, G.; Guallini, L.; Mandelli, G.: Osservazioni sull'azione patogena sperimentale di (Paeeilomyces variotiBainier; 1907). Arch Vet Ita119: 185-198, 1968 12 Rodrigues, M. M.; MacLeod, D.: Exogenous fungal endophthalmitis caused by Paecilomyees. Am J Opthalmol 79: 687-690, 1975 13 Silver, M. D.; Tuffnell, P. G.; Bigelow, W. G.: Endocarditis caused by Paecilomyces varioti affecting an aortic valve allograft. J Thorac Cardiovasc Surg 61: 278-281, 1971 14 Uys, C. J .; Don, P. A.; Schrire, V.; Barnard, C. N.: Endocarditis following cardiac surgery due to the fungusPaeciiomyces. S Afr Med J 37: 1276-1280, 1963 15 Wolf, P. L.; Russell, B.; Shimoda, A.: Practical clinical microbiology and mycology techniques and interpretations, pp. 429-530; John Wiley and Sons, New York, 1975
Request reprints from Dr. Robert W. Fleischman, Department of Pathology, Mason Research Institute, Worcester, MA 01608 (USA).
