t h e s u r g e o n x x x ( 2 0 1 4 ) 1 e6
Available online at www.sciencedirect.com
ScienceDirect The Surgeon, Journal of the Royal Colleges of Surgeons of Edinburgh and Ireland www.thesurgeon.net
Causative organisms in revision total hip & knee arthroplasty for infection: Increasing multiantibiotic resistance in coagulase-negative Staphylococcus and the implications for antibiotic prophylaxis A.M. Malhas a,*, R. Lawton a, M. Reidy a, D. Nathwani b, B.A. Clift a a
Department of Trauma and Orthopaedics, Ward 18/19, Ninewells Hospital, NHS Tayside, Dundee, Scotland DD2 1UB, UK b Department of Infectious Diseases, Ward 18/19, Ninewells Hospital, NHS Tayside, Dundee, Scotland DD2 1UB, UK
article info
abstract
Article history:
Background and purpose: Increasing resistance among post-operative Coagulase-negative
Received 20 February 2014
Staphylococci (CNS) infections have been reported. We present our experience changing
Received in revised form
resistance patterns.
2 April 2014
Methods: We examined microbiological results from hip and knee revisions from 2001 to
Accepted 7 April 2014
2010 and compared resistance to all Staphylococcus aureus (SA) and CNS cultured from
Available online xxx
regional pan-speciality sources, in order to examine the patterns of antibiotic resistance. Main findings: 72 revisions in 67 patients were included. The most common organisms were
Keywords:
SA (36%) and CNS (35%). Resistance to methicillin was 72% for CNS versus 20% for SA and
Revision surgery
resistance to gentamicin was 40% for CNS versus 4% for SA. Among all regional (back-
Arthroplasty
ground pan-speciality) cultures SA resistance to methicillin fell from 32% to 16% from 2006
Infection
to 10 with no change in gentamicin resistance at 3%. During the same period resistance of
Antibiotic resistance
CNS to methicillin and gentamicin increased from 63% to 70% and 32%e47% respectively.
Total hip replacement
Conclusions: Resistance of CNS to both methicillin and gentamicin is higher than with SA
Total knee replacement
and appears to be increasing. At least 32% of CNS and 4% of SA from infected TKRs/THRs were resistant to our current prophylaxis regime. These changing patterns of resistance may have implications for future antibiotic prophylaxis regimes. ª 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Department of Trauma and Orthopaedics, Ward 18/19, Ninewells Hospital, NHS Tayside, Dundee, Scotland DD2 1UB, UK. Tel.: þ44 07776291869. E-mail addresses: [email protected], [email protected] (A.M. Malhas). http://dx.doi.org/10.1016/j.surge.2014.04.002 1479-666X/ª 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Malhas AM, et al., Causative organisms in revision total hip & knee arthroplasty for infection: Increasing multi-antibiotic resistance in coagulase-negative Staphylococcus and the implications for antibiotic prophylaxis, The Surgeon (2014), http://dx.doi.org/10.1016/j.surge.2014.04.002
2
t h e s u r g e o n x x x ( 2 0 1 4 ) 1 e6
Introduction Revision arthroplasty surgery for an infected prosthesis is associated with significant costs and morbidity.1 Annually, approximately 2500 Total hip replacements (THR) and 1,100, Total knee replacements (TKR) are revised due to infection in England and Wales.2 Treatment often requires multiple operations, prolonged hospital stays, long-term antibiotics and rehabilitation.1 Although infection rates remain low at around 1e3%,1 with increasing numbers of primary arthroplasties being performed, revision surgery of infected total hip (THR) and total knee (TKR) replacements is an increasing burden on health services.1,2 Prophylactic antibiotics have an established role in the prevention of infection in arthroplasty surgery at the time of implantation. Historically, Lidwell et al.3 reported a reduction in infection rates in arthroplasty surgery from 2.3% to 0.6%. Antibiotic loaded cement as a mechanism of antibiotic delivery has also been shown to reduce infection rates.4,5 Data from the Norwegian Arthroplasty Register confirms infection rates of 0.4e0.5% with the use of antibiotics.5 Their data also demonstrates that the combined use of systemic antibiotics and antibiotic loaded cement gives a greater reduction in infection rates than either delivery system alone. This use of antibiotics is therefore the most important proven prophylactic strategy in arthroplasty surgery when compared to other measures such as laminar flow and body exhaust suits.3 The current Scottish Intercollegiate Guidelines Network (SIGN) guidelines recommend the selection of prophylactic antibiotics in accordance with local resistance profiles and 24 h of antibiotic prophylaxis to cover the intra- and postoperative period coupled with antibiotic laden cement (in cemented implants).6 The commonest causative organisms of arthroplasty infections are both commensals. Coagulase-negative Staphylococcus (CNS), of which Staphylococcus epidermis (SE) is the most common species, and Staphylococcus aureus (SA) are the commonest organisms, accounting for 60e80% of infections.7,8 Commensal CNS are more common, with carriage rates up to 90%. SA carriage rates are lower with around 20% of the population persistently colonized and 30% intermittently colonized.7e9 Despite being a less common cause of these infections, SA has traditionally received the most attention due to the combination of its greater pathogenicity and the emergence of antibiotic resistance.5 Concerns over methicillin resistant S. aureus (MRSA) have led to the national introduction of measures designed to prevent the spread of resistance including preadmission screening and decolonisation of MRSA carriers in accordance with both NICE guidelines in the England and Whales10 and SIGN guidelines in Scotland.6 While the important role of CNS in causing prosthetic joint infections has long been recognised11 they are often regarded as less virulent than SA, with little emphasis on colonisation and the emergence of antibiotic resistance. Their increasing importance as core infecting pathogens have been confirmed in recent studies.7,8 Furthermore, recent screening studies show that whilst MRSA rates on pre-op skin swabs remain low at 1e5%,9 MR CNS rates are much higher at around 25%.10 Indeed, comparing MR rates for SA and CNS specifically at
revision arthroplasty show significantly lower rates for MRSA of
Available online at www.sciencedirect.com
ScienceDirect The Surgeon, Journal of the Royal Colleges of Surgeons of Edinburgh and Ireland www.thesurgeon.net
Causative organisms in revision total hip & knee arthroplasty for infection: Increasing multiantibiotic resistance in coagulase-negative Staphylococcus and the implications for antibiotic prophylaxis A.M. Malhas a,*, R. Lawton a, M. Reidy a, D. Nathwani b, B.A. Clift a a
Department of Trauma and Orthopaedics, Ward 18/19, Ninewells Hospital, NHS Tayside, Dundee, Scotland DD2 1UB, UK b Department of Infectious Diseases, Ward 18/19, Ninewells Hospital, NHS Tayside, Dundee, Scotland DD2 1UB, UK
article info
abstract
Article history:
Background and purpose: Increasing resistance among post-operative Coagulase-negative
Received 20 February 2014
Staphylococci (CNS) infections have been reported. We present our experience changing
Received in revised form
resistance patterns.
2 April 2014
Methods: We examined microbiological results from hip and knee revisions from 2001 to
Accepted 7 April 2014
2010 and compared resistance to all Staphylococcus aureus (SA) and CNS cultured from
Available online xxx
regional pan-speciality sources, in order to examine the patterns of antibiotic resistance. Main findings: 72 revisions in 67 patients were included. The most common organisms were
Keywords:
SA (36%) and CNS (35%). Resistance to methicillin was 72% for CNS versus 20% for SA and
Revision surgery
resistance to gentamicin was 40% for CNS versus 4% for SA. Among all regional (back-
Arthroplasty
ground pan-speciality) cultures SA resistance to methicillin fell from 32% to 16% from 2006
Infection
to 10 with no change in gentamicin resistance at 3%. During the same period resistance of
Antibiotic resistance
CNS to methicillin and gentamicin increased from 63% to 70% and 32%e47% respectively.
Total hip replacement
Conclusions: Resistance of CNS to both methicillin and gentamicin is higher than with SA
Total knee replacement
and appears to be increasing. At least 32% of CNS and 4% of SA from infected TKRs/THRs were resistant to our current prophylaxis regime. These changing patterns of resistance may have implications for future antibiotic prophylaxis regimes. ª 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Department of Trauma and Orthopaedics, Ward 18/19, Ninewells Hospital, NHS Tayside, Dundee, Scotland DD2 1UB, UK. Tel.: þ44 07776291869. E-mail addresses: [email protected], [email protected] (A.M. Malhas). http://dx.doi.org/10.1016/j.surge.2014.04.002 1479-666X/ª 2014 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Malhas AM, et al., Causative organisms in revision total hip & knee arthroplasty for infection: Increasing multi-antibiotic resistance in coagulase-negative Staphylococcus and the implications for antibiotic prophylaxis, The Surgeon (2014), http://dx.doi.org/10.1016/j.surge.2014.04.002
2
t h e s u r g e o n x x x ( 2 0 1 4 ) 1 e6
Introduction Revision arthroplasty surgery for an infected prosthesis is associated with significant costs and morbidity.1 Annually, approximately 2500 Total hip replacements (THR) and 1,100, Total knee replacements (TKR) are revised due to infection in England and Wales.2 Treatment often requires multiple operations, prolonged hospital stays, long-term antibiotics and rehabilitation.1 Although infection rates remain low at around 1e3%,1 with increasing numbers of primary arthroplasties being performed, revision surgery of infected total hip (THR) and total knee (TKR) replacements is an increasing burden on health services.1,2 Prophylactic antibiotics have an established role in the prevention of infection in arthroplasty surgery at the time of implantation. Historically, Lidwell et al.3 reported a reduction in infection rates in arthroplasty surgery from 2.3% to 0.6%. Antibiotic loaded cement as a mechanism of antibiotic delivery has also been shown to reduce infection rates.4,5 Data from the Norwegian Arthroplasty Register confirms infection rates of 0.4e0.5% with the use of antibiotics.5 Their data also demonstrates that the combined use of systemic antibiotics and antibiotic loaded cement gives a greater reduction in infection rates than either delivery system alone. This use of antibiotics is therefore the most important proven prophylactic strategy in arthroplasty surgery when compared to other measures such as laminar flow and body exhaust suits.3 The current Scottish Intercollegiate Guidelines Network (SIGN) guidelines recommend the selection of prophylactic antibiotics in accordance with local resistance profiles and 24 h of antibiotic prophylaxis to cover the intra- and postoperative period coupled with antibiotic laden cement (in cemented implants).6 The commonest causative organisms of arthroplasty infections are both commensals. Coagulase-negative Staphylococcus (CNS), of which Staphylococcus epidermis (SE) is the most common species, and Staphylococcus aureus (SA) are the commonest organisms, accounting for 60e80% of infections.7,8 Commensal CNS are more common, with carriage rates up to 90%. SA carriage rates are lower with around 20% of the population persistently colonized and 30% intermittently colonized.7e9 Despite being a less common cause of these infections, SA has traditionally received the most attention due to the combination of its greater pathogenicity and the emergence of antibiotic resistance.5 Concerns over methicillin resistant S. aureus (MRSA) have led to the national introduction of measures designed to prevent the spread of resistance including preadmission screening and decolonisation of MRSA carriers in accordance with both NICE guidelines in the England and Whales10 and SIGN guidelines in Scotland.6 While the important role of CNS in causing prosthetic joint infections has long been recognised11 they are often regarded as less virulent than SA, with little emphasis on colonisation and the emergence of antibiotic resistance. Their increasing importance as core infecting pathogens have been confirmed in recent studies.7,8 Furthermore, recent screening studies show that whilst MRSA rates on pre-op skin swabs remain low at 1e5%,9 MR CNS rates are much higher at around 25%.10 Indeed, comparing MR rates for SA and CNS specifically at
revision arthroplasty show significantly lower rates for MRSA of
