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Propionibacterium avidum Causing Native Breast Abscess
Case Report
Propionibacterium avidum Causing Native Breast Abscess Richard S. Bradbury, B.Biomed.Sci., Ph.D.,1 Sanchia J. Warren, MB.BS., FRACP,2 David A. Jones, B.App.Sci., M.Med.Sci,2 and Margaret J. Whipp, Ph.D.,3 1School of Medicine, University of Tasmania, Hobart, Tasmania, Australia, 2Department of Microbiology and Infectious Diseases, Royal Hobart Hospital, Hobart, and 3Microbiological Diagnostic Unit, Public Health Laboratory, University of Melbourne, Parkville, Victoria, Australia
Introduction Propionibacterium avidum is traditionally considered an organism of low pathogenicity and is seldom associated with human infection. Rare reports of breast abscess caused by P. avidum have been almost exclusively associated with immunosuppression or prior surgical intervention. There are a small number of reports of this organism causing splenic abscess, septic arthritis, sacroiliitis, and osteomyelitis, as well as one report of perianal abscess (1-5). All these infections occurred in immunocompromised patients, patients with pre-existing medical conditions, or following a medical intervention (1-8). The organism has also been associated rarely with breast abscess (6-8), with only one such case being reported in a previously healthy individual who had no history of prior surgical intervention (8). Corresponding Author: Dr. Richard Bradbury, School of Medicine, University of Tasmania, Private bag 34, Hobart, TAS, 7000, Australia. Tel.: +61 3 6226 4669. Fax: +61 3 6226 474. E-mail: [email protected]
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Because of its low growth rate, it is possible that infections with P. avidum are underreported. We report a case of recurrent breast abscess caused by P. avidum that resulted from mammary duct ectasia in the absence of immunosuppression or prior surgery and propose that the organism is an underrecognized cause of such infections.
Case Report A 44-year-old mother of three presented to her surgeon for management of a recurrent breast abscess. For at least 4 years, she had experienced recurrent inflammation at the “one o’clock” position of the right nipple. There was a significant discharge draining from the area during times of inflammation. Antimicrobial therapy had been attempted (data not available), but the abscess returned. A mammogram conducted 2 years previously was normal. The patient had a history of mastitis with all three of her children but was otherwise well. Given the frequency of the episodes of breast inflammation, occurring approximately once every 6 months, she progressed to © 2011 Elsevier
surgical management. At the time of surgery, there was no external evidence of inflammation; however, an incision revealed a deep pocket of pus underlying the skin. The mammary duct was examined, and black and green debris was noted within. The involved ductal tissue was excised. Histopathology of the tissue revealed a cavity with granulation tissue, chronic active inflammation, and fibrosis. Adjacent ducts that were excised exhibited duct ectasia with dilatation and chronic inflammation. There was no evidence of cell atypia or malignancy. At a post-surgical follow-up visit, pus was expressed from the wound. Over the next 20 postoperative days, the exudate diminished and the wound healed. There have been no further abscesses at this site. However, she was again seen by her surgeon with a new abscess at the “5 o’clock” position on the same breast. Currently, she is being followed for observation with no definitive plan for surgical management. Excised tissue was received in the laboratory for microscopy, culture, and Clinical Microbiology Newsletter 33:19,2011
antibiotic susceptibility testing. A direct Gram-stained smear of the macerated tissue showed many inflammatory cells, but no bacteria were seen. The specimen was inoculated onto chocolate, blood, and MacConkey agars and incubated at 37°C. No growth was seen on the inoculated agar plates after 48 h of incubation. In our laboratory, specimens from which large numbers of inflammatory cells are seen on direct Gram-stained smears but in which no organisms are seen undergo an extended period of incubation under aerobic conditions at 37°C for 21 days. After 5 days of incubation of the breast tissue culture, convex and slightly mucoid, whitepigmented colonies approximately 1 mm in diameter were observed on the chocolate and blood agar plates. The organism produced large zones of beta hemolysis on the blood agar plate. Gram-stained smears of the colonies showed pleomorphic, gram-positive bacilli of diphtheroid morphology. The isolate was catalase positive and nonmotile. Initial identification was performed by using an API Coryne strip (bioMérieux SA, Marcy L’Etoile, France), which gave a biocode reading of 0462325, corresponding to a 99.9% identification of P. avidum (t = 0.95). This identification was confirmed by sequencing the entire 16S rRNA gene, the resultant sequence with 99.5% identical to that of the P. avidum type strain.
cal intervention. In light of our findings, P. avidum may be an underrecognized cause of native soft tissue infection in such patients. Our case highlights the importance of using extended periods of incubation for the detection of slowly growing organisms. Infections with P. avidum and other slowly growing organisms may not be detected without such measures. Propionibacterium species are generally susceptible to β-lactam antibiotics and vancomycin (10). Previously reported antimicrobial treatments for P. avidum breast abscess have included combinations of penicillin, amoxicillinclavulanate, doxycycline, and moxifloxacin (6-8). However, cases of P. avidum breast abscess have often involved a complicated course. Our patient had repeated courses of antibiotic therapy, recurrence of the abscess, and at least one surgical intervention before she presented to our hospital. In two other documented cases, the abscess continued, and surgical intervention was required or was being considered at the time of publication (6,8). In another two published cases, antibiotic treatment of the abscess appeared to be effective (6,7), although in one case, at the time of this writing, the patient had been followed only for 8 weeks and wound healing was not yet completed (7). In our case, surgical management was chosen as the sole method of treatment.
Discussion
Conclusion
P. avidum is typically a member of the normal skin flora of the axilla, perineum, and groin (9). The organism has rarely been reported as a cause of breast abscess. In almost all cases of documented infection, previous surgical intervention was a predisposing factor (6-8). This case represents only the second description (8) of a P. avidum strain causing breast abscess in the absence of immunosuppression or previous surgi-
P. avidum has been reported rarely as causing breast abscess and normally in association with a prior surgical procedure or immunosuppression. Because of low rate of growth and its role as a commensal skin organism, infections may be missed or easily overlooked. We suggest that this organism is an underrecognized cause of breast abscess in the absence of prior trauma. We recommend that P. avidum be considered
Clinical Microbiology Newsletter 33:19,2011
© 2011 Elsevier
in the differential diagnosis of breast abscess and that an extended period of incubation be performed on any bacteriologic culture from any “sterile” breast abscess that shows no growth after only 2 days of incubation. References 1. Estoppy, O. et al. 1997. Propionibacterium avidum sacroiliitis and osteomyelitis. Rev. Rheum. Engl. 67:54-56. 2. Dunne, W.M., Jr. et al. 1986. Propionibacterium avidum as the etiologic agent of splenic abscess. Diagn. Microbiol. Infect. Dis. 4:87-92. 3. Vohra, A. et al. 1998. Splenic abscess caused by Propionibacterium avidum as a complication of cardiac catheterization. Clin. Infect. Dis. 26:770-771. 4. Wang, T.K.F., P.C.Y. Woo, and K.Y. Yuen. 2002. Perianal abscess caused by Propionibacterium avidum in a cirrhotic patient. New Microbiologica 25:239-242. 5. Million, M. et al. 2008. Septic arthritis of the hip with Propionibacterium avidum bacteremia after intraarticular treatment for hip osteoarthritis. Joint Bone Spine 75:356-358. 6. Levin, B., A. Lee, and T. Gottlieb. 2008. Propionibacterium avidum as the cause of severe breast infection following reduction mammoplasty. ANZ J. Surg. 78318-319. 7. Panagea, S. 2005. Breast abscess caused by Propionibacterium avidum following breast reduction surgery: case report and a reviw of the literature. J. Infect. 51:e253-e255. 8. Werno, A.M. 2004. Breast abscess caused by Propionibacterium avidum. Clin. Microbiol. Newsl. 29:70-71. 9. Benediktsdóttir, E. and A. Hambraeus. 1982. Dispersal of non-sporeforming anaerobic bacteria from the skin. J. Hyg. 88:487-500. 10. Citron, D.M. and D.W. Hecht. 2003. Susceptibility test methods: anaerobic bacteria, p. 1141-1148. In P.R. Murray et al. (ed.), Manual of clinical microbiology, 8th ed. ASM Press, Washington, DC.
0196-4399/00 (see frontmatter)
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Propionibacterium avidum Causing Native Breast Abscess Richard S. Bradbury, B.Biomed.Sci., Ph.D.,1 Sanchia J. Warren, MB.BS., FRACP,2 David A. Jones, B.App.Sci., M.Med.Sci,2 and Margaret J. Whipp, Ph.D.,3 1School of Medicine, University of Tasmania, Hobart, Tasmania, Australia, 2Department of Microbiology and Infectious Diseases, Royal Hobart Hospital, Hobart, and 3Microbiological Diagnostic Unit, Public Health Laboratory, University of Melbourne, Parkville, Victoria, Australia
Introduction Propionibacterium avidum is traditionally considered an organism of low pathogenicity and is seldom associated with human infection. Rare reports of breast abscess caused by P. avidum have been almost exclusively associated with immunosuppression or prior surgical intervention. There are a small number of reports of this organism causing splenic abscess, septic arthritis, sacroiliitis, and osteomyelitis, as well as one report of perianal abscess (1-5). All these infections occurred in immunocompromised patients, patients with pre-existing medical conditions, or following a medical intervention (1-8). The organism has also been associated rarely with breast abscess (6-8), with only one such case being reported in a previously healthy individual who had no history of prior surgical intervention (8). Corresponding Author: Dr. Richard Bradbury, School of Medicine, University of Tasmania, Private bag 34, Hobart, TAS, 7000, Australia. Tel.: +61 3 6226 4669. Fax: +61 3 6226 474. E-mail: [email protected]
150
0196-4399/00 (see frontmatter)
Because of its low growth rate, it is possible that infections with P. avidum are underreported. We report a case of recurrent breast abscess caused by P. avidum that resulted from mammary duct ectasia in the absence of immunosuppression or prior surgery and propose that the organism is an underrecognized cause of such infections.
Case Report A 44-year-old mother of three presented to her surgeon for management of a recurrent breast abscess. For at least 4 years, she had experienced recurrent inflammation at the “one o’clock” position of the right nipple. There was a significant discharge draining from the area during times of inflammation. Antimicrobial therapy had been attempted (data not available), but the abscess returned. A mammogram conducted 2 years previously was normal. The patient had a history of mastitis with all three of her children but was otherwise well. Given the frequency of the episodes of breast inflammation, occurring approximately once every 6 months, she progressed to © 2011 Elsevier
surgical management. At the time of surgery, there was no external evidence of inflammation; however, an incision revealed a deep pocket of pus underlying the skin. The mammary duct was examined, and black and green debris was noted within. The involved ductal tissue was excised. Histopathology of the tissue revealed a cavity with granulation tissue, chronic active inflammation, and fibrosis. Adjacent ducts that were excised exhibited duct ectasia with dilatation and chronic inflammation. There was no evidence of cell atypia or malignancy. At a post-surgical follow-up visit, pus was expressed from the wound. Over the next 20 postoperative days, the exudate diminished and the wound healed. There have been no further abscesses at this site. However, she was again seen by her surgeon with a new abscess at the “5 o’clock” position on the same breast. Currently, she is being followed for observation with no definitive plan for surgical management. Excised tissue was received in the laboratory for microscopy, culture, and Clinical Microbiology Newsletter 33:19,2011
antibiotic susceptibility testing. A direct Gram-stained smear of the macerated tissue showed many inflammatory cells, but no bacteria were seen. The specimen was inoculated onto chocolate, blood, and MacConkey agars and incubated at 37°C. No growth was seen on the inoculated agar plates after 48 h of incubation. In our laboratory, specimens from which large numbers of inflammatory cells are seen on direct Gram-stained smears but in which no organisms are seen undergo an extended period of incubation under aerobic conditions at 37°C for 21 days. After 5 days of incubation of the breast tissue culture, convex and slightly mucoid, whitepigmented colonies approximately 1 mm in diameter were observed on the chocolate and blood agar plates. The organism produced large zones of beta hemolysis on the blood agar plate. Gram-stained smears of the colonies showed pleomorphic, gram-positive bacilli of diphtheroid morphology. The isolate was catalase positive and nonmotile. Initial identification was performed by using an API Coryne strip (bioMérieux SA, Marcy L’Etoile, France), which gave a biocode reading of 0462325, corresponding to a 99.9% identification of P. avidum (t = 0.95). This identification was confirmed by sequencing the entire 16S rRNA gene, the resultant sequence with 99.5% identical to that of the P. avidum type strain.
cal intervention. In light of our findings, P. avidum may be an underrecognized cause of native soft tissue infection in such patients. Our case highlights the importance of using extended periods of incubation for the detection of slowly growing organisms. Infections with P. avidum and other slowly growing organisms may not be detected without such measures. Propionibacterium species are generally susceptible to β-lactam antibiotics and vancomycin (10). Previously reported antimicrobial treatments for P. avidum breast abscess have included combinations of penicillin, amoxicillinclavulanate, doxycycline, and moxifloxacin (6-8). However, cases of P. avidum breast abscess have often involved a complicated course. Our patient had repeated courses of antibiotic therapy, recurrence of the abscess, and at least one surgical intervention before she presented to our hospital. In two other documented cases, the abscess continued, and surgical intervention was required or was being considered at the time of publication (6,8). In another two published cases, antibiotic treatment of the abscess appeared to be effective (6,7), although in one case, at the time of this writing, the patient had been followed only for 8 weeks and wound healing was not yet completed (7). In our case, surgical management was chosen as the sole method of treatment.
Discussion
Conclusion
P. avidum is typically a member of the normal skin flora of the axilla, perineum, and groin (9). The organism has rarely been reported as a cause of breast abscess. In almost all cases of documented infection, previous surgical intervention was a predisposing factor (6-8). This case represents only the second description (8) of a P. avidum strain causing breast abscess in the absence of immunosuppression or previous surgi-
P. avidum has been reported rarely as causing breast abscess and normally in association with a prior surgical procedure or immunosuppression. Because of low rate of growth and its role as a commensal skin organism, infections may be missed or easily overlooked. We suggest that this organism is an underrecognized cause of breast abscess in the absence of prior trauma. We recommend that P. avidum be considered
Clinical Microbiology Newsletter 33:19,2011
© 2011 Elsevier
in the differential diagnosis of breast abscess and that an extended period of incubation be performed on any bacteriologic culture from any “sterile” breast abscess that shows no growth after only 2 days of incubation. References 1. Estoppy, O. et al. 1997. Propionibacterium avidum sacroiliitis and osteomyelitis. Rev. Rheum. Engl. 67:54-56. 2. Dunne, W.M., Jr. et al. 1986. Propionibacterium avidum as the etiologic agent of splenic abscess. Diagn. Microbiol. Infect. Dis. 4:87-92. 3. Vohra, A. et al. 1998. Splenic abscess caused by Propionibacterium avidum as a complication of cardiac catheterization. Clin. Infect. Dis. 26:770-771. 4. Wang, T.K.F., P.C.Y. Woo, and K.Y. Yuen. 2002. Perianal abscess caused by Propionibacterium avidum in a cirrhotic patient. New Microbiologica 25:239-242. 5. Million, M. et al. 2008. Septic arthritis of the hip with Propionibacterium avidum bacteremia after intraarticular treatment for hip osteoarthritis. Joint Bone Spine 75:356-358. 6. Levin, B., A. Lee, and T. Gottlieb. 2008. Propionibacterium avidum as the cause of severe breast infection following reduction mammoplasty. ANZ J. Surg. 78318-319. 7. Panagea, S. 2005. Breast abscess caused by Propionibacterium avidum following breast reduction surgery: case report and a reviw of the literature. J. Infect. 51:e253-e255. 8. Werno, A.M. 2004. Breast abscess caused by Propionibacterium avidum. Clin. Microbiol. Newsl. 29:70-71. 9. Benediktsdóttir, E. and A. Hambraeus. 1982. Dispersal of non-sporeforming anaerobic bacteria from the skin. J. Hyg. 88:487-500. 10. Citron, D.M. and D.W. Hecht. 2003. Susceptibility test methods: anaerobic bacteria, p. 1141-1148. In P.R. Murray et al. (ed.), Manual of clinical microbiology, 8th ed. ASM Press, Washington, DC.
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