Download Osteomyelitits Due to Linezolid-Resistant

Osteomyelitits Due to
Linezolid-Resistant
Staphylococcus epidermidis
To the Editor—Described are the first
reported cases of osteomyelitis due to
linezolid-resistant Staphylococcus epidermidis.
Case 1 was a 73-year-old woman with
severe peripheral vascular disease and
a recent diagnosis 6 months prior to
admission of polymicrobial osteomyelitis of the left calcaneus, which had
required multiple heel debridements,
partial calcanectomy, and a skin grafting
procedure. Linezolid and piperacillintazobactam were administered throughout her surgical course and for 6 weeks
following her skin graft, at which time
she was switched to linezolid monotherapy (linezolid was eventually discontinued 2 weeks prior to admission).
She was admitted after a fall at home
and was found to have purulent drainage from her left lower extremity graft
with exposed bone. Imipenem-cilastatin
was started empirically, and linezolid
was added 2 days later. A deep wound
swab obtained 2 days after admission
isolated a coagulase-negative staphylococcus species that was not subjected
to further laboratory testing. Surgical
intervention was delayed due to initial patient refusal but was ultimately
performed 2 weeks later. Bone cultures obtained intraoperatively isolated
linezolid-resistant S. epidermidis (Table 1).
The patient was eventually treated successfully with intravenous vancomycin
and extensive plastic surgery.
Case 2 was a 55-year-old man with
chronically infected patellar hardware
and associated left patellar osteomyelitis.
He had been receiving linezolid for
6 weeks prior to admission from an
outside prescriber following his most
recent patellar debridement. He presented after a fall at his long-term
acute care facility and was found to
have a swollen left knee with purulent
drainage. Culture of this drainage grew
Table 1. Antimicrobial Susceptibilities of Linezolid-Resistant Staphylococcus epidermidis
Isolatesa
Minimum Inhibitory Concentration, lg/mL
Antimicrobial
Isolate 1
Isolate 2
Linezolidb
.256
.256
Ceftriaxone
.32
#8
Ciprofloxacin
.2
.2
Clindamycin
.4
Daptomycin
Erythromycin
#0.5
2
Gentamicin
.8
.8
Levofloxacin
.4
.4
Oxacillin
.2
2
Penicillin
.8
2
Quinupristin-dalfopristin
2
1
Rifampin
#1
#1
Tetracycline
Trimethoprim-sulfamethoxazole
#4
2-38
#4
2-38
2
1
Vancomycin
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CID 2012:54 (15 April)
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4
#0.5
2
a
Performed with MicroScan combination breakpoint panels (Siemens Healthcare Diagnostics).
b
Confirmed by Etest (bioMèrieux).
CORRESPONDENCE
methicillin-resistant S. epidermidis susceptible to linezolid (minimum inhibitory concentration, #2 lg/mL). Bone
cultures obtained during hardware removal 5 days later isolated 2 colony
types of S. epidermidis: one that was
linezolid susceptible and another that
was linezolid resistant (Table 1). Due
to a reported allergy to vancomycin,
the patient was transitioned to daptomycin. He underwent 5 additional
debridements in the month following
hardware removal, and the linezolidresistant S. epidermidis strain was isolated
from each of 4 debridements in which
cultures were obtained. After his surgical course was completed and his
wound was closed, he received an additional 6 weeks of daptomycin therapy with successful suppression of his
infection.
These are the first reports of osteomyelitis due to linezolid-resistant
S. epidermidis. As in similar cases of
linezolid-resistant staphylococcal infections, both patients received prolonged
courses of linezolid in the setting of
inadequate surgical debridement prior
to isolation of a linezolid-resistant organism [1–9]. Although a detailed molecular analysis could not be performed,
the antimicrobial susceptibility profiles
of each isolate were different, suggesting that linezolid resistance developed
independently during therapy (Table 1).
Because of the deep-seated nature of osteomyelitis, the inconsistent concentrations of linezolid achievable in infected
bone [10], and the frequency with
which staphylococci cause osteomyelitis, we believe our experience could be
replicated. The potential for Staphylococcus aureus to acquire linezolid resistance in a similar clinical setting is
of particular concern. Linezolid should
be reserved for patients failing or intolerant of conventional therapies for
osteomyelitis.
Notes
Financial support. This work was supported by the use of resources at Utah Valley
Regional Medical Center.
Potential conflicts of interest. I. Z. A. has
received speaker fees from Pfizer, Forest
Pharmaceuticals, Merck, and Wyeth Pharmaceuticals. All other authors report no potential
conflicts.
All authors have submitted the ICMJE Form
for Disclosure of Potential Conflicts of Interest.
Conflicts that the editors consider relevant to the
content of the manuscript have been disclosed.
Russell J. Benefield,1 George K. Hinde,2 and
Igor Z. Abolnik3
1Department of Pharmacy, University of Utah Hospital,
Salt Lake City; and 2Central Laboratory, Intermountain
Healthcare, Murray; and 3Infectious Diseases, Central
Utah Multispecialty Clinic, Provo, Utah
a patient with left ventricular assist system.
Scand J Infect Dis 2007; 39:463–5.
3. Peeters MJ, Sarria JC. Clinical characteristics
of linezolid-resistant Staphylococcus aureus
infections. Am J Med Sci 2005; 330:102–4.
4. Wilson P, Andrews JA, Charlesworth R, et al.
Linezolid resistance in clinical isolates of
Staphylococcus aureus. J Antimicrob Chemother 2003; 51:186–8.
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linezolid treatment in two paediatric cystic
fibrosis patients. J Antimicrob Chemother
2010; 65:442–5.
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Linezolid resistance in a clinical isolate of
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et al. Emergence of linezolid-resistant
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J Antimicrob Chemother 2010; 65:2001–4.
8. Bonilla H, Huband MD, Seidel J, et al.
Multicity outbreak of linezolid-resistant
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9. Treviño M, Martinez-Lamas L, RomeroJung PA, Giráldez JM, Alvarez-Escudero J,
Regueiro BJ. Endemic linezolid-resistant
Staphylococcus epidermidis in a critical care
unit. Eur J Clin Microbiol Infect Dis 2009;
28:527–33.
10. Kutscha-Lissberg F, Hebler U, Muhr G,
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Chemother 2003; 47:3964–6.
References
1. Gales AC, Sader HS, Andrade SS, Lutz L,
Machado A, Barth AL. Emergence of linezolid-resistant Staphylococcus aureus during
treatment of pulmonary infection in a patient with cystic fibrosis. Int J Antimicrob
Agents 2006; 27:300–2.
2. Kola A, Kirschner P, Gohrbandt B, et al. An
infection with linezolid-resistant S. aureus in
Correspondence: Russell J. Benefield, PharmD, Department
of Pharmacy, University of Utah Hospital, 50 N Medical Dr,
A-050, Salt Lake City, UT 84132 ([email protected]).
Clinical Infectious Diseases 2012;54(8):1216–7
Ó The Author 2012. Published by Oxford University Press on
behalf of the Infectious Diseases Society of America. All rights
reserved. For Permissions, please e-mail: journals.permissions@
oup.com.
DOI: 10.1093/cid/cis018
CORRESPONDENCE
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