Anaerobe 34 (2015) 84e85
Contents lists available at ScienceDirect
Anaerobe journal homepage: www.elsevier.com/locate/anaerobe
Note
Actinobaculum schaalii bacteremia: A report of two cases Lemuel R. Non a, *, Allison Nazinitsky a, Mark D. Gonzalez b, Carey-Ann D. Burnham b, Rupa Patel a a b
Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, USA Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 26 February 2015 Received in revised form 27 March 2015 Accepted 10 April 2015 Available online 13 April 2015
We report two cases of bacteremia with Actinobaculum schaalii, a rarely reported, anaerobic, Grampositive bacterium. The first case was a patient with renal cancer who developed pyelonephritis after cryoablation, and the second was a patient who developed sepsis after a urogenital procedure. Bacteremia resolved after administration of empiric antibiotic therapy. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Actinobaculum schaalii Anaerobe Bacteremia MALDI-TOF
1. Introduction Actinobaculum schaalii is an emerging uropathogen that is well documented in Europe [1e4]. To date, only one case has been reported in North America [5]. Herein, we report the first two cases of A. schaalii bacteremia in the United States identified using matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). 2. Case one A 61-year-old male with history of chronic kidney disease and left renal cell carcinoma, status post-cryoablation three weeks prior to admission presented to an outside hospital with fever of 40.1 C and severe flank pain. Physical examination revealed costovertebral angle tenderness. Laboratory studies upon admission revealed a white blood cell (WBC) count of 11.5 103 WBC/mm3 (reference range: 3.8e9.8 103/mm3). Urinalysis disclosed 3 þ leukocyte esterase, negative nitrites, and 29 WBCs/hpf. An abdominal CT demonstrated left perinephric stranding with hydronephrosis. Upon transfer to Barnes-Jewish Hospital, the patient was administered intravenous daptomycin and cefepime, and then underwent
* Corresponding author. Infectious Diseases Division, Washington University School of Medicine, Box 8051, 660 S. Euclid Ave, St. Louis, MO 63110, USA. E-mail address: [email protected] (L.R. Non). http://dx.doi.org/10.1016/j.anaerobe.2015.04.006 1075-9964/© 2015 Elsevier Ltd. All rights reserved.
percutaneous nephrostomy tube placement. A Gram stain of an aspirate from the procedure demonstrated Gram-positive bacilli (GPB) and culture grew >50,000 colonies/mL of A. schaalii on sheep's blood agar. The organism was identified using the Bruker Biotyper MALDI-TOF MS system as previously described [6] with score of 2.104. Aerobic and anaerobic blood culture bottles collected at the prior hospital, using the BD BACTEC FX blood culture system, also grew A. schaalii, which was identified using the Bruker Biotyper MALDI-TOF MS with a score of 2.067. His antibiotics were deescalated to intravenous ceftriaxone 2 gm IV every 24 h and repeat blood cultures three days later were sterile. He completed ceftriaxone for 2 weeks and then was transitioned to oral amoxicillin 500 mg every 8 h for 2 weeks. 3. Case two A 54-year-old female presented with complaints of abdominal pain and hematochezia, and was found to have a large pelvic mass on CT imaging. Her initial WBC was 11.8 103/mm3 and her urinalysis demonstrated 5e10 WBCs/hpf, 1 þ leukocyte esterase, and negative nitrites. To investigate the mass, she underwent pelvic examination under anesthesia with endocervical curettage, which was non-diagnostic, and rigid sigmoidoscopy, which revealed a fungating rectal mass 8 cm from the anal verge, eventually identified as invasive squamous cell carcinoma. One day postprocedure, she developed fevers of 38.8 C, tachycardia of
L.R. Non et al. / Anaerobe 34 (2015) 84e85
112 bpm, and hypotension. Urine culture demonstrated insignificant growth, but aerobic blood culture using the VersaTREK blood culture system grew GPB, later identified as A. schaalii using the Bruker Biotyper MALDI-TOF MS with a score of 2.13. She was started on intravenous ertapenem 1 gm every 24 h with defervescence and clearance of her bacteremia on subsequent blood cultures four days after. She completed four weeks of ertapenem, which was switched to oral amoxicillin-clavulanic acid 875 mg twice daily for four weeks. 4. Discussion A. schaalii was first described as a separate species from Actinomyces and Arcanobacterium in 1997. It is a Gram-positive, nonmotile, non-spore-forming, non-acid-fast, facultative anaerobic bacilli [1]. The habitat of A. schaalii is unknown but it is believed to be a commensal of the human genital or urinary tract, but may cause infection in those predisposed to developing urinary tract infections (UTI) [1]. In a prospective study in Denmark from 2008 to 2009, the researchers detected A. schaalii in as many as 22% of samples taken from asymptomatic patients >60 years of age using quantitative real-time PCR [2]. However, it is not uncommon to isolate A. schaalii in younger patients [7]. Risk factors identified include old age, presence of genitourinary abnormalities, urinary catheterizations, and chronic kidney disease [1,4,7,8]. Urinary tract infection, including acute and chronic cystitis, and pyelonephritis, is the most common clinical syndrome associated with A. schaalii. It is usually suspected in patients with compatible symptoms, urinalysis showing pyuria with presence of leukocyte esterase but no nitrites and finding of GPB on Gram stain [1,7]. A. schaalii has also been reported in cases of epididymitis, osteomyelitis, abscesses, Fournier's gangrene, endocarditis and, as in our 2 cases, bacteremia. In a retrospective review from 2009 to 2013 in a major hospital in Sweden, 17 cases of A. schaalii bacteremia were identified. Fifteen (88%) patients had symptoms of UTI, 13 (77%) had urinary catheterization, 1 had urethral stricture, and 2 patients had underlying malignancies. Urine culture was done on 15 patients and, interestingly, none of them grew A. schaalii [9]. In our first patient, he likely acquired A. schaalii bacteremia due to translocation of bacteria from his underlying pyelonephritis or from the cryoablation procedure; whereas the second patient likely acquired the bacteremia from manipulation of her urogenital tract. As there is no commercially available biochemical identification system that reliably identifies this bacteria, diagnosis is made with molecular methods, usually by 16S rRNA gene sequencing, or by MALDI-TOF MS [1,10,11]. In one study, the investigators were able to reliably identify A. schaalii in 11 of 11 clinical isolates using MALDITOF MS with Bruker Biotyper scores above 2.0, which is considered a score compatible with accurate species level identification [10]. Farfour evaluated the use of MALDI in identifying GPB, with 16S rRNA gene sequencing as the reference identification technique, and the investigators were able to correctly identify A. schaalii in 100% of their isolates [11]. In both of our cases, antimicrobial susceptibility testing was not performed as there is no formal methodology established for A. schaalii, but the gradient diffusion method has been used in various clinical settings. Cattoir et al. evaluated the in vitro susceptibilities of human clinical isolates of A. schaalii using gradient diffusion with interpretation based on clinical breakpoints for anaerobes [12]. They demonstrated that all the isolates were susceptible to amoxicillin, ceftriaxone, gentamicin, vancomycin, linezolid and nitrofurantoin. It was also found to be intrinsically resistant to metronidazole, similar to other non-spore-forming,
85
anaerobic Gram-positive rods. All the isolates were also resistant to ciprofloxacin and colistin. Only 15% were susceptible to trimethoprim-sulfamethoxazole [7,12]. Clinically, agents such as amoxicillin, amoxicillin-clavulanate, clindamycin, cefuroxime, gentamicin, ceftriaxone and piperacillin-tazobactam have been used successfully in treating A. schaalii [5,7,13e16]. Optimal duration of antibiotic therapy is not clearly defined, but a duration of more than two weeks has been suggested because of documented clinical failure with one-week regimens [1,17]. 5. Conclusion A. schaalii is a uropathogen that can potentially cause bacteremia. The identification of this organism relies on newer technologies, such as MALDI-TOF MS, which is important since this bacterium is resistant to many of the common empiric therapies used for UTI and usually requires a longer treatment duration to prevent treatment failure. Acknowledgments We are grateful to the Barnes-Jewish Hospital Clinical Microbiology laboratory for their ongoing efforts for the patients of Barnes Jewish Hospital. References [1] V. Cattoir, Actinobaculum schaalii: review of an emerging uropathogen, J. Infect. 64 (2012) 260e267. [2] S. Bank, A. Jensen, T.M. Hansen, K.M. Søby, J. Prag, Actinobaculum schaalii, a common uropathogen in elderly patients, Den. Emerg. Infect. Dis. 16 (2010) 76e80. [3] M. Reinhard, et al., Ten cases of Actinobaculum schaalii infection: clinical relevance, bacterial identification, and antibiotic susceptibility, J. Clin. Microbiol. 43 (2005) 5305e5308. [4] S. Tschudin-sutter, R. Frei, M. Weisser, D. Goldenberger, A.F. Widmer, Actinobaculum schaalii e invasive pathogen or innocent bystander? A retrospective observational study, BMC Infect. Dis. 11 (2011) 1e5. [5] O.E. Larios, et al., First report of Actinobaculum schaalii urinary tract infection in North America, Diagn. Microbiol. Infect. Dis. 67 (2010) 282e285. [6] E. McElvania Tekippe, S. Shuey, D.W. Winkler, M.a Butler, C.-A.D. Burnham, Optimizing identification of clinically relevant gram-positive organisms by use of the Bruker Biotyper matrix-assisted laser desorption ionization-time of flight mass spectrometry system, J. Clin. Microbiol. 51 (2013) 1421e1427. [7] C. Beguelin, et al., Actinobaculum schaalii: clinical observation of 20 cases, Clin. Microbiol. Infect. 17 (2011) 1027e1031. €hnk, A.B. Olsen, J.B. Prag, K.M. Søby, Severe phimosis as cause of uro[8] M.L. Jo sepsis with Actinobaculum schaalii, Ugeskr. Laeger 174 (2012) 1539e1540. [9] J. Sandlund, M. Glimåker, A. Svahn, A. Brauner, Bacteraemia caused by Actinobaculum schaalii: an overlooked pathogen? Scand. J. Infect. Dis. 46 (2014) 605e608. [10] T. Tuuminen, P. Suomala, I. Harju, Actinobaculum schaalii: identification with MALDI-TOF, New Microbes New Infect. 2 (2014) 38e41. [11] E. Farfour, et al., Evaluation of the Andromas matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of aerobically growing gram-positive bacilli, J. Clin. Microbiol. 50 (2012) 2702e2707. [12] V. Cattoir, A. Varca, G. Greub, P. Legrand, R. Lienhard, In vitro susceptibility of Actinobaculum schaalii to 12 antimicrobial agents and molecular analysis of fluoroquinolone resistance, J. Antimicrob. Chermother. (2010) 2514e2517, http://dx.doi.org/10.1093/jac/dkq383. [13] P. Haller, et al., Vertebral osteomyelitis caused by Actinobaculum schaalii: a difficult-to-diagnose and potentially invasive uropathogen, Eur. J. Clin. Microbiol. Infect. Dis. 26 (2007) 667e670. [14] A. Gupta, P. Gupta, A. Khaira, Actinobaculum schaalii pyelonephritis in a kidney allograft recipient, Iran. J. Kidney Dis. 6 (2012) 386e388. [15] M. Hoenigl, et al., Endocarditis caused by Actinobaculum schaalii, Emerg. Infect. Dis. 16 (2010) 1171e1173. [16] R. Lotte, et al., A rare case of histopathological bladder necrosis associated with Actinobaculum schaalii: the incremental value of an accurate microbiological diagnosis using 16S rDNA sequencing, Anaerobe 26 (2014) 46e48. [17] C. Barberis, et al., Case report Actinobaculum schaalii causing urinary tract infections: report of four cases from Argentina, J. Infect. Dev. Ctries. 8 (2014) 240e244.
Contents lists available at ScienceDirect
Anaerobe journal homepage: www.elsevier.com/locate/anaerobe
Note
Actinobaculum schaalii bacteremia: A report of two cases Lemuel R. Non a, *, Allison Nazinitsky a, Mark D. Gonzalez b, Carey-Ann D. Burnham b, Rupa Patel a a b
Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, USA Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, USA
a r t i c l e i n f o
a b s t r a c t
Article history: Received 26 February 2015 Received in revised form 27 March 2015 Accepted 10 April 2015 Available online 13 April 2015
We report two cases of bacteremia with Actinobaculum schaalii, a rarely reported, anaerobic, Grampositive bacterium. The first case was a patient with renal cancer who developed pyelonephritis after cryoablation, and the second was a patient who developed sepsis after a urogenital procedure. Bacteremia resolved after administration of empiric antibiotic therapy. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Actinobaculum schaalii Anaerobe Bacteremia MALDI-TOF
1. Introduction Actinobaculum schaalii is an emerging uropathogen that is well documented in Europe [1e4]. To date, only one case has been reported in North America [5]. Herein, we report the first two cases of A. schaalii bacteremia in the United States identified using matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). 2. Case one A 61-year-old male with history of chronic kidney disease and left renal cell carcinoma, status post-cryoablation three weeks prior to admission presented to an outside hospital with fever of 40.1 C and severe flank pain. Physical examination revealed costovertebral angle tenderness. Laboratory studies upon admission revealed a white blood cell (WBC) count of 11.5 103 WBC/mm3 (reference range: 3.8e9.8 103/mm3). Urinalysis disclosed 3 þ leukocyte esterase, negative nitrites, and 29 WBCs/hpf. An abdominal CT demonstrated left perinephric stranding with hydronephrosis. Upon transfer to Barnes-Jewish Hospital, the patient was administered intravenous daptomycin and cefepime, and then underwent
* Corresponding author. Infectious Diseases Division, Washington University School of Medicine, Box 8051, 660 S. Euclid Ave, St. Louis, MO 63110, USA. E-mail address: [email protected] (L.R. Non). http://dx.doi.org/10.1016/j.anaerobe.2015.04.006 1075-9964/© 2015 Elsevier Ltd. All rights reserved.
percutaneous nephrostomy tube placement. A Gram stain of an aspirate from the procedure demonstrated Gram-positive bacilli (GPB) and culture grew >50,000 colonies/mL of A. schaalii on sheep's blood agar. The organism was identified using the Bruker Biotyper MALDI-TOF MS system as previously described [6] with score of 2.104. Aerobic and anaerobic blood culture bottles collected at the prior hospital, using the BD BACTEC FX blood culture system, also grew A. schaalii, which was identified using the Bruker Biotyper MALDI-TOF MS with a score of 2.067. His antibiotics were deescalated to intravenous ceftriaxone 2 gm IV every 24 h and repeat blood cultures three days later were sterile. He completed ceftriaxone for 2 weeks and then was transitioned to oral amoxicillin 500 mg every 8 h for 2 weeks. 3. Case two A 54-year-old female presented with complaints of abdominal pain and hematochezia, and was found to have a large pelvic mass on CT imaging. Her initial WBC was 11.8 103/mm3 and her urinalysis demonstrated 5e10 WBCs/hpf, 1 þ leukocyte esterase, and negative nitrites. To investigate the mass, she underwent pelvic examination under anesthesia with endocervical curettage, which was non-diagnostic, and rigid sigmoidoscopy, which revealed a fungating rectal mass 8 cm from the anal verge, eventually identified as invasive squamous cell carcinoma. One day postprocedure, she developed fevers of 38.8 C, tachycardia of
L.R. Non et al. / Anaerobe 34 (2015) 84e85
112 bpm, and hypotension. Urine culture demonstrated insignificant growth, but aerobic blood culture using the VersaTREK blood culture system grew GPB, later identified as A. schaalii using the Bruker Biotyper MALDI-TOF MS with a score of 2.13. She was started on intravenous ertapenem 1 gm every 24 h with defervescence and clearance of her bacteremia on subsequent blood cultures four days after. She completed four weeks of ertapenem, which was switched to oral amoxicillin-clavulanic acid 875 mg twice daily for four weeks. 4. Discussion A. schaalii was first described as a separate species from Actinomyces and Arcanobacterium in 1997. It is a Gram-positive, nonmotile, non-spore-forming, non-acid-fast, facultative anaerobic bacilli [1]. The habitat of A. schaalii is unknown but it is believed to be a commensal of the human genital or urinary tract, but may cause infection in those predisposed to developing urinary tract infections (UTI) [1]. In a prospective study in Denmark from 2008 to 2009, the researchers detected A. schaalii in as many as 22% of samples taken from asymptomatic patients >60 years of age using quantitative real-time PCR [2]. However, it is not uncommon to isolate A. schaalii in younger patients [7]. Risk factors identified include old age, presence of genitourinary abnormalities, urinary catheterizations, and chronic kidney disease [1,4,7,8]. Urinary tract infection, including acute and chronic cystitis, and pyelonephritis, is the most common clinical syndrome associated with A. schaalii. It is usually suspected in patients with compatible symptoms, urinalysis showing pyuria with presence of leukocyte esterase but no nitrites and finding of GPB on Gram stain [1,7]. A. schaalii has also been reported in cases of epididymitis, osteomyelitis, abscesses, Fournier's gangrene, endocarditis and, as in our 2 cases, bacteremia. In a retrospective review from 2009 to 2013 in a major hospital in Sweden, 17 cases of A. schaalii bacteremia were identified. Fifteen (88%) patients had symptoms of UTI, 13 (77%) had urinary catheterization, 1 had urethral stricture, and 2 patients had underlying malignancies. Urine culture was done on 15 patients and, interestingly, none of them grew A. schaalii [9]. In our first patient, he likely acquired A. schaalii bacteremia due to translocation of bacteria from his underlying pyelonephritis or from the cryoablation procedure; whereas the second patient likely acquired the bacteremia from manipulation of her urogenital tract. As there is no commercially available biochemical identification system that reliably identifies this bacteria, diagnosis is made with molecular methods, usually by 16S rRNA gene sequencing, or by MALDI-TOF MS [1,10,11]. In one study, the investigators were able to reliably identify A. schaalii in 11 of 11 clinical isolates using MALDITOF MS with Bruker Biotyper scores above 2.0, which is considered a score compatible with accurate species level identification [10]. Farfour evaluated the use of MALDI in identifying GPB, with 16S rRNA gene sequencing as the reference identification technique, and the investigators were able to correctly identify A. schaalii in 100% of their isolates [11]. In both of our cases, antimicrobial susceptibility testing was not performed as there is no formal methodology established for A. schaalii, but the gradient diffusion method has been used in various clinical settings. Cattoir et al. evaluated the in vitro susceptibilities of human clinical isolates of A. schaalii using gradient diffusion with interpretation based on clinical breakpoints for anaerobes [12]. They demonstrated that all the isolates were susceptible to amoxicillin, ceftriaxone, gentamicin, vancomycin, linezolid and nitrofurantoin. It was also found to be intrinsically resistant to metronidazole, similar to other non-spore-forming,
85
anaerobic Gram-positive rods. All the isolates were also resistant to ciprofloxacin and colistin. Only 15% were susceptible to trimethoprim-sulfamethoxazole [7,12]. Clinically, agents such as amoxicillin, amoxicillin-clavulanate, clindamycin, cefuroxime, gentamicin, ceftriaxone and piperacillin-tazobactam have been used successfully in treating A. schaalii [5,7,13e16]. Optimal duration of antibiotic therapy is not clearly defined, but a duration of more than two weeks has been suggested because of documented clinical failure with one-week regimens [1,17]. 5. Conclusion A. schaalii is a uropathogen that can potentially cause bacteremia. The identification of this organism relies on newer technologies, such as MALDI-TOF MS, which is important since this bacterium is resistant to many of the common empiric therapies used for UTI and usually requires a longer treatment duration to prevent treatment failure. Acknowledgments We are grateful to the Barnes-Jewish Hospital Clinical Microbiology laboratory for their ongoing efforts for the patients of Barnes Jewish Hospital. References [1] V. Cattoir, Actinobaculum schaalii: review of an emerging uropathogen, J. Infect. 64 (2012) 260e267. [2] S. Bank, A. Jensen, T.M. Hansen, K.M. Søby, J. Prag, Actinobaculum schaalii, a common uropathogen in elderly patients, Den. Emerg. Infect. Dis. 16 (2010) 76e80. [3] M. Reinhard, et al., Ten cases of Actinobaculum schaalii infection: clinical relevance, bacterial identification, and antibiotic susceptibility, J. Clin. Microbiol. 43 (2005) 5305e5308. [4] S. Tschudin-sutter, R. Frei, M. Weisser, D. Goldenberger, A.F. Widmer, Actinobaculum schaalii e invasive pathogen or innocent bystander? A retrospective observational study, BMC Infect. Dis. 11 (2011) 1e5. [5] O.E. Larios, et al., First report of Actinobaculum schaalii urinary tract infection in North America, Diagn. Microbiol. Infect. Dis. 67 (2010) 282e285. [6] E. McElvania Tekippe, S. Shuey, D.W. Winkler, M.a Butler, C.-A.D. Burnham, Optimizing identification of clinically relevant gram-positive organisms by use of the Bruker Biotyper matrix-assisted laser desorption ionization-time of flight mass spectrometry system, J. Clin. Microbiol. 51 (2013) 1421e1427. [7] C. Beguelin, et al., Actinobaculum schaalii: clinical observation of 20 cases, Clin. Microbiol. Infect. 17 (2011) 1027e1031. €hnk, A.B. Olsen, J.B. Prag, K.M. Søby, Severe phimosis as cause of uro[8] M.L. Jo sepsis with Actinobaculum schaalii, Ugeskr. Laeger 174 (2012) 1539e1540. [9] J. Sandlund, M. Glimåker, A. Svahn, A. Brauner, Bacteraemia caused by Actinobaculum schaalii: an overlooked pathogen? Scand. J. Infect. Dis. 46 (2014) 605e608. [10] T. Tuuminen, P. Suomala, I. Harju, Actinobaculum schaalii: identification with MALDI-TOF, New Microbes New Infect. 2 (2014) 38e41. [11] E. Farfour, et al., Evaluation of the Andromas matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of aerobically growing gram-positive bacilli, J. Clin. Microbiol. 50 (2012) 2702e2707. [12] V. Cattoir, A. Varca, G. Greub, P. Legrand, R. Lienhard, In vitro susceptibility of Actinobaculum schaalii to 12 antimicrobial agents and molecular analysis of fluoroquinolone resistance, J. Antimicrob. Chermother. (2010) 2514e2517, http://dx.doi.org/10.1093/jac/dkq383. [13] P. Haller, et al., Vertebral osteomyelitis caused by Actinobaculum schaalii: a difficult-to-diagnose and potentially invasive uropathogen, Eur. J. Clin. Microbiol. Infect. Dis. 26 (2007) 667e670. [14] A. Gupta, P. Gupta, A. Khaira, Actinobaculum schaalii pyelonephritis in a kidney allograft recipient, Iran. J. Kidney Dis. 6 (2012) 386e388. [15] M. Hoenigl, et al., Endocarditis caused by Actinobaculum schaalii, Emerg. Infect. Dis. 16 (2010) 1171e1173. [16] R. Lotte, et al., A rare case of histopathological bladder necrosis associated with Actinobaculum schaalii: the incremental value of an accurate microbiological diagnosis using 16S rDNA sequencing, Anaerobe 26 (2014) 46e48. [17] C. Barberis, et al., Case report Actinobaculum schaalii causing urinary tract infections: report of four cases from Argentina, J. Infect. Dev. Ctries. 8 (2014) 240e244.
