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Actinomyces odontolyticus as a rare cause of thoracoactinomycosis—A case report
ARTICLE IN PRESS Respiratory Medicine Extra (2007) 3, 159–160
respiratory MEDICINE Extra
CASE REPORT
Actinomyces odontolyticus as a rare cause of thoracoactinomycosis—A case report Rajesh Thomasa, Devasahayam J. Christophera,, M.K. Lalithab, Promila Mohan Rajb, Balamugesh Thagakunama, Prince Jamesa a
Department of Pulmonary Medicine, Christian Medical College, Vellore 632 004, India Department of Microbiology, Christian Medical College, Vellore 632 004, India
b
Received 7 July 2007; accepted 1 August 2007
KEYWORDS Thoracoactinomycosis; Actinomyces odontolyticus; Solitary pulmonary nodule
Summary Actinomycosis, a bacterial infection in humans is most commonly caused by Actinomyces israelii. Less frequent causes include Actinomyces odontolyticus and Actinomyces viscosus. We present a rare case of thoracoactinomycosis caused by A. odontolyticus. It presented as a solitary pulmonary nodule, and formed neither draining sinuses nor granule formation, which is an unusual presentation. There are only nine cases of A. odontolyticus causing thoracoactinomycosis in the world literature, and this is the first such case reported from India. & 2007 Elsevier Ltd. All rights reserved.
Introduction Actinomyces odontolyticus causing thoracoactinomycosis in a healthy individual has been very rarely documented in literature. The first case of thoracoactinomycosis caused by A. odontolyticus was reported in 19931 and this is the first such case reported from India.
Case report A 32-year-old male presented to us with a 1-year history of cough and recurrent, small-volume hemoptysis. He did not Corresponding author. Tel.: +91 416 2282859.
E-mail address: [email protected] (D.J. Christopher). 1744-9049/$ - see front matter & 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.rmedx.2007.08.004
complain of fever, anorexia or loss of weight. There was no history of pulmonary tuberculosis, or diseases leading to an immuno-compromised state. General and systemic examination was unremarkable. Routine blood and urine examination were normal. Routine sputum culture grew normal flora. Chest roentgenogram and computed tomography (CT) scan of the thorax showed a 2 2 cm nodule in the posterobasal segment of the right lower lobe. Flexible bronchoscopy revealed no endobronchial pathology. Bronchial wash cytology was negative for malignant cells. Sputum and bronchial wash smear and culture were negative for acidfast bacilli. Fine needle aspiration cytology of the nodule showed only inflammatory cells, and there was no evidence of malignancy. In view of persistent consolidation and lack of evidence of malignancy, he was treated with antibiotics for 6 weeks.
ARTICLE IN PRESS 160
Figure 1 Gram stain of the needle aspirate from the lung nodule showing Gram-positive, irregularly stained, thin, branching, filamentous forms suggestive of Actinomyces species.
The CT scan of thorax was repeated after 6 weeks. This showed a marginal increase in size of the nodule in the right lower lobe. Therefore, a CT-guided needle biopsy of the nodule was done, histopathology of which showed nonspecific inflammation. However, Gram stain of the aspirate (Figure 1) showed Gram-positive, irregularly stained, thin, branching, filamentous forms. Kinyon’s acid-fast stain showed non-acid-fast, branching, filamentous forms. The material was inoculated into brain–heart infusion agar (BHIA), sheep blood agar (SBA) and multiple thioglycollate broths. Three thioglycollate broths were incubated aerobically and the remaining three thioglycollate broths, BHIA and SBA plates were incubated anaerobically. The organism grew after 14 days of anaerobic incubation only on the primary SBA plate. Initially the colonies were non-haemolytic, white, 0.5–1.0 mm in diameter, and smooth. On further incubation, it turned red. Microscopy of the colony revealed small, filamentous forms with rudimentary branching and diphtheroidal forms. In the thioglycollate broth, it produced a granular growth at the bottom two-thirds of the tube. It was identified as A. odontolyticus by conventional and biochemical tests.2 The patient was advised treatment with oral Penicillin for 6 months. Subsequent follow-up could not be done as the patient did not return for further treatment.
Discussion Actinomycosis is a chronic disease characterized by abscess formation, tissue fibrosis and draining sinuses caused by Actinomyces species. Actinomyces are Gram-positive, nonspore forming and non-acid-fast organisms with diphtheroidal or thin filamental and pleomorphic prokaryotic forms, which are 0.4–1.0 mm wide. The filaments may be up to 50 mm in length with true branching.2 Actinomycosis is most commonly caused by A. israelii3 and less frequently, by A. odontolyticus or A. viscosus.4 Actinomycosis can affect virtually any site in the body and usually presents as one of the three forms; cervico-facial, thoracic or abdomino-genital. The most frequent site of human infection is the cervico-facial area, accounting for about 40–50% of cases.3–5 Approximately 15% of the actinomycoses occurs in thorax.3 Extension of the cervicofacial actinomycosis or aspiration of the infectious agent
R. Thomas et al. leads to thoracoactinomycosis. Thoracoactinomycosis may involve lung, pleura, mediastinum or chest wall. It can be mistaken for malignant disease or for infections as tuberculosis, nocardiosis and histoplasmosis.6 Our patient had isolated lung involvement as a solitary pulmonary nodule and there was no evidence of involvement of head and neck, or any other site. A. odontolyticus is thought to be less virulent than A. israelii, and it causes cutaneous, cervico-facial, peritoneal and brain abscesses.7,8 The first case of thoracoactinomycosis caused by A. odontolyticus was reported in 1993.1 Thoracopulmonary cases with A. odontolyticus infections are very rare and only nine cases have been documented.9 The insidious nature of the infection makes diagnosis difficult. CT or sonographic-guided biopsies are the best method to obtain material for appropriate diagnosis. A high index of suspicion and proper techniques for collection and submission of specimens is essential for appropriate diagnosis. Surgical removal of the infected tissue was the mainstay of the treatment in the pre-antibiotic era. Presently, it is difficult to define the true incidence of actinomycosis because common use of antibiotics eradicates many mild cases. Therefore actinomycosis has become an uncommon entity. This case was unique for several reasons. Thoracoactinomycosis presenting as a solitary pulmonary nodule is very rare. There was no evidence of any other site of involvement as cervico-facial or peritoneal abscess formation. Finally, A. odontolyticus causing thoracoactinomycosis in a healthy individual has been very rarely documented in literature and this is the first such case reported from India.
Conflict of interest statement This is to confirm that none of the authors have a conflict of interest to declare in relation to this work.
References 1. Verrot D, Disdier P, Harla JR, et al. Pulmonary actinomycosis: caused by A. odontolyticus? Rev Med Intern 1993;14:179–81. 2. Bowden GHW. Actinomyces. 9th ed Topley and Wilson’s microbiology and microbial infection, vol. 2. London: Edward Arnold; 1998. p. 445–62. 3. Bennhoff DF. Actinomycosis: diagnostic and therapeutic considerations and a review of 32 cases. Laryngoscope 1984;94: 1198–217. 4. Russo TA. Agents of actinomycosis. In: Mandell GL, Bennett JE, Dolin R, editors. Mandel, Douglas and Bennett’s principles and practice of infectious disease. 4th ed. New York: Churchill Livingstone; 1995. p. 2280–8. 5. Rippon JW. Actinomycosis. Medical mycology: the pathogenic fungi and the pathogenic Actinomycetes, 3rd ed. Philadelphia: WB Saunders; 1988. 6. Joel S. Patient clinical information; Actinomyces. John Hopkins microbiology newsletter, vol. 15, August 5, 1996. p. 30. 7. Peloux Y, Raoult D, Chardon H, et al. A. odontolyticus infections: review of six patients. J Infect 1985;11:125–9. 8. Hutton R, Behrens R. A. odontolyticus as a cause of brain abscess. J Infect 1979;1:195–7. 9. Takiguchi Yasuo, Terano Takashi, Hirai Akira. Lung abscess caused by A. odontolyticus. Intern Med 2003;42:723–5.
respiratory MEDICINE Extra
CASE REPORT
Actinomyces odontolyticus as a rare cause of thoracoactinomycosis—A case report Rajesh Thomasa, Devasahayam J. Christophera,, M.K. Lalithab, Promila Mohan Rajb, Balamugesh Thagakunama, Prince Jamesa a
Department of Pulmonary Medicine, Christian Medical College, Vellore 632 004, India Department of Microbiology, Christian Medical College, Vellore 632 004, India
b
Received 7 July 2007; accepted 1 August 2007
KEYWORDS Thoracoactinomycosis; Actinomyces odontolyticus; Solitary pulmonary nodule
Summary Actinomycosis, a bacterial infection in humans is most commonly caused by Actinomyces israelii. Less frequent causes include Actinomyces odontolyticus and Actinomyces viscosus. We present a rare case of thoracoactinomycosis caused by A. odontolyticus. It presented as a solitary pulmonary nodule, and formed neither draining sinuses nor granule formation, which is an unusual presentation. There are only nine cases of A. odontolyticus causing thoracoactinomycosis in the world literature, and this is the first such case reported from India. & 2007 Elsevier Ltd. All rights reserved.
Introduction Actinomyces odontolyticus causing thoracoactinomycosis in a healthy individual has been very rarely documented in literature. The first case of thoracoactinomycosis caused by A. odontolyticus was reported in 19931 and this is the first such case reported from India.
Case report A 32-year-old male presented to us with a 1-year history of cough and recurrent, small-volume hemoptysis. He did not Corresponding author. Tel.: +91 416 2282859.
E-mail address: [email protected] (D.J. Christopher). 1744-9049/$ - see front matter & 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.rmedx.2007.08.004
complain of fever, anorexia or loss of weight. There was no history of pulmonary tuberculosis, or diseases leading to an immuno-compromised state. General and systemic examination was unremarkable. Routine blood and urine examination were normal. Routine sputum culture grew normal flora. Chest roentgenogram and computed tomography (CT) scan of the thorax showed a 2 2 cm nodule in the posterobasal segment of the right lower lobe. Flexible bronchoscopy revealed no endobronchial pathology. Bronchial wash cytology was negative for malignant cells. Sputum and bronchial wash smear and culture were negative for acidfast bacilli. Fine needle aspiration cytology of the nodule showed only inflammatory cells, and there was no evidence of malignancy. In view of persistent consolidation and lack of evidence of malignancy, he was treated with antibiotics for 6 weeks.
ARTICLE IN PRESS 160
Figure 1 Gram stain of the needle aspirate from the lung nodule showing Gram-positive, irregularly stained, thin, branching, filamentous forms suggestive of Actinomyces species.
The CT scan of thorax was repeated after 6 weeks. This showed a marginal increase in size of the nodule in the right lower lobe. Therefore, a CT-guided needle biopsy of the nodule was done, histopathology of which showed nonspecific inflammation. However, Gram stain of the aspirate (Figure 1) showed Gram-positive, irregularly stained, thin, branching, filamentous forms. Kinyon’s acid-fast stain showed non-acid-fast, branching, filamentous forms. The material was inoculated into brain–heart infusion agar (BHIA), sheep blood agar (SBA) and multiple thioglycollate broths. Three thioglycollate broths were incubated aerobically and the remaining three thioglycollate broths, BHIA and SBA plates were incubated anaerobically. The organism grew after 14 days of anaerobic incubation only on the primary SBA plate. Initially the colonies were non-haemolytic, white, 0.5–1.0 mm in diameter, and smooth. On further incubation, it turned red. Microscopy of the colony revealed small, filamentous forms with rudimentary branching and diphtheroidal forms. In the thioglycollate broth, it produced a granular growth at the bottom two-thirds of the tube. It was identified as A. odontolyticus by conventional and biochemical tests.2 The patient was advised treatment with oral Penicillin for 6 months. Subsequent follow-up could not be done as the patient did not return for further treatment.
Discussion Actinomycosis is a chronic disease characterized by abscess formation, tissue fibrosis and draining sinuses caused by Actinomyces species. Actinomyces are Gram-positive, nonspore forming and non-acid-fast organisms with diphtheroidal or thin filamental and pleomorphic prokaryotic forms, which are 0.4–1.0 mm wide. The filaments may be up to 50 mm in length with true branching.2 Actinomycosis is most commonly caused by A. israelii3 and less frequently, by A. odontolyticus or A. viscosus.4 Actinomycosis can affect virtually any site in the body and usually presents as one of the three forms; cervico-facial, thoracic or abdomino-genital. The most frequent site of human infection is the cervico-facial area, accounting for about 40–50% of cases.3–5 Approximately 15% of the actinomycoses occurs in thorax.3 Extension of the cervicofacial actinomycosis or aspiration of the infectious agent
R. Thomas et al. leads to thoracoactinomycosis. Thoracoactinomycosis may involve lung, pleura, mediastinum or chest wall. It can be mistaken for malignant disease or for infections as tuberculosis, nocardiosis and histoplasmosis.6 Our patient had isolated lung involvement as a solitary pulmonary nodule and there was no evidence of involvement of head and neck, or any other site. A. odontolyticus is thought to be less virulent than A. israelii, and it causes cutaneous, cervico-facial, peritoneal and brain abscesses.7,8 The first case of thoracoactinomycosis caused by A. odontolyticus was reported in 1993.1 Thoracopulmonary cases with A. odontolyticus infections are very rare and only nine cases have been documented.9 The insidious nature of the infection makes diagnosis difficult. CT or sonographic-guided biopsies are the best method to obtain material for appropriate diagnosis. A high index of suspicion and proper techniques for collection and submission of specimens is essential for appropriate diagnosis. Surgical removal of the infected tissue was the mainstay of the treatment in the pre-antibiotic era. Presently, it is difficult to define the true incidence of actinomycosis because common use of antibiotics eradicates many mild cases. Therefore actinomycosis has become an uncommon entity. This case was unique for several reasons. Thoracoactinomycosis presenting as a solitary pulmonary nodule is very rare. There was no evidence of any other site of involvement as cervico-facial or peritoneal abscess formation. Finally, A. odontolyticus causing thoracoactinomycosis in a healthy individual has been very rarely documented in literature and this is the first such case reported from India.
Conflict of interest statement This is to confirm that none of the authors have a conflict of interest to declare in relation to this work.
References 1. Verrot D, Disdier P, Harla JR, et al. Pulmonary actinomycosis: caused by A. odontolyticus? Rev Med Intern 1993;14:179–81. 2. Bowden GHW. Actinomyces. 9th ed Topley and Wilson’s microbiology and microbial infection, vol. 2. London: Edward Arnold; 1998. p. 445–62. 3. Bennhoff DF. Actinomycosis: diagnostic and therapeutic considerations and a review of 32 cases. Laryngoscope 1984;94: 1198–217. 4. Russo TA. Agents of actinomycosis. In: Mandell GL, Bennett JE, Dolin R, editors. Mandel, Douglas and Bennett’s principles and practice of infectious disease. 4th ed. New York: Churchill Livingstone; 1995. p. 2280–8. 5. Rippon JW. Actinomycosis. Medical mycology: the pathogenic fungi and the pathogenic Actinomycetes, 3rd ed. Philadelphia: WB Saunders; 1988. 6. Joel S. Patient clinical information; Actinomyces. John Hopkins microbiology newsletter, vol. 15, August 5, 1996. p. 30. 7. Peloux Y, Raoult D, Chardon H, et al. A. odontolyticus infections: review of six patients. J Infect 1985;11:125–9. 8. Hutton R, Behrens R. A. odontolyticus as a cause of brain abscess. J Infect 1979;1:195–7. 9. Takiguchi Yasuo, Terano Takashi, Hirai Akira. Lung abscess caused by A. odontolyticus. Intern Med 2003;42:723–5.