[Show abstract][Hide abstract] ABSTRACT: Meticillin-resistant Staphylococcus aureus (MRSA) infection continues to be a substantial global problem with significant associated morbidity and mortality. This review summarises the discussions that took place at the 4th MRSA Consensus Conference in relation to the current treatment options for serious MRSA infections and how to optimise whichever therapy is embarked upon. It highlights the many challenges faced by both the laboratory and clinicians in the diagnosis and treatment of MRSA infections.
Journal of Global Antimicrobial Resistance 09/2014; 2(3). DOI:10.1016/j.jgar.2014.03.009
[Show abstract][Hide abstract] ABSTRACT: Around the world, Staphylococcus aureus remains a dominant cause of bacteraemia. Whilst meticillin resistance remains the major phenotype of concern, various levels of reduced glycopeptide susceptibility are emerging with increasing frequency. The most common MRSA phenotypes now have raised vancomycin MICs within the susceptible range (MICs of 1-2mg/L). This phenomenon, known as MIC creep, is hotly contested and often denied. Key to detecting MIC creep may be to examine isolates fresh, as freezing can allow reversion to wild-type MIC, presumably by loss of mutations. Treatment failure is common with vancomycin and it is uncertain whether higher doses are beneficial. At the other extreme, when enough mutations have accumulated, full VISA status is achieved, although this can also be unstable on storage. Heteroresistant and VISA strains can be considered the inevitable end result of continued MIC creep and are even more likely to fail glycopeptide treatment. Currently full vancomycin resistance is uncommon, with only approximately 20 strains described and confirmed worldwide. Empirical treatment for patients with undefined Gram-positive sepsis can undoubtedly be improved by knowledge of MRSA status, so this is a potential advantage of hospital admission screening. If a patient is risk-assessed or screen-positive for MRSA, and infection is not serious, then vancomycin or teicoplanin is appropriate empirical therapy, providing loading doses are given to achieve therapeutic concentrations immediately (trough 15mg/L). For life-threatening infections, the glycopeptides are inadequate unless the isolate is likely to be fully susceptible (Etest<1.5mg/L). If not, daptomycin (8-10mg/L) can be used as monotherapy but the MIC should be measured as soon as possible.
International journal of antimicrobial agents 05/2013; 42. DOI:10.1016/j.ijantimicag.2013.04.006 · 4.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Infection with meticillin-resistant Staphylococcus aureus (MRSA) continues to have significant morbidity and mortality. Vancomycin, which has been the mainstay of treatment of invasive MRSA infections, has several drawbacks related to its pharmacological properties as well as varying degrees of emerging resistance. These resistant subpopulations are difficult to detect, making therapy with vancomycin less reliable. The newer agents such as linezolid, daptomycin, ceftaroline, and the newer glycopeptides telavancin and oritavancin are useful alternatives that could potentially replace vancomycin in the treatment of certain conditions. By summarising the discussions that took place at the III MRSA Consensus Conference in relation to the current place of vancomycin in therapy and the potential of the newer agents to replace vancomycin, this review focuses on the challenges faced by the laboratory and by clinicians in the diagnosis and treatment of MRSA infections.
Journal of Global Antimicrobial Resistance 03/2013; 1(1):23–30. DOI:10.1016/j.jgar.2013.01.002
[Show abstract][Hide abstract] ABSTRACT: The International Society of Chemotherapy's Working Groups on Antibiotic Resistance and Antibiotic Stewardship convened a half-day workshop on the burden of multidrug-resistant organisms in the Asia-Pacific. This short review is a summary of their discussion and conclusions.
Journal of Global Antimicrobial Resistance 01/2013; 2(1). DOI:10.1016/j.jgar.2013.10.005
[Show abstract][Hide abstract] ABSTRACT: To describe secular trends in Staphylococcus aureus bacteraemia (SAB) and to assess the impacts of infection control practices, including universal methicillin-resistant Staphylococcus aureus (MRSA) admission screening on associated clinical burdens.
Retrospective cohort study and multivariate time-series analysis linking microbiology, patient management and health intelligence databases.
Teaching hospital in North East Scotland.
All patients admitted to Aberdeen Royal Infirmary between 1 January 2006 and 31 December 2010: n=420 452 admissions and 1 430 052 acute occupied bed days (AOBDs).
Universal admission screening programme for MRSA (August 2008) incorporating isolation and decolonisation. PRIMARY AND SECONDARY MEASURES: Hospital-wide prevalence density, hospital-associated incidence density and death within 30 days of MRSA or methicillin-sensitive Staphylococcus aureus (MSSA) bacteraemia.
Between 2006 and 2010, prevalence density of all SAB declined by 41%, from 0.73 to 0.50 cases/1000 AOBDs (p=0.002 for trend), and 30-day mortality from 26% to 14% (p=0.013). Significant reductions were observed in MRSA bacteraemia only. Overnight admissions screened for MRSA rose from 43% during selective screening to >90% within 4 months of universal screening. In multivariate time-series analysis (R(2) 0.45 to 0.68), universal screening was associated with a 19% reduction in prevalence density of MRSA bacteraemia (-0.035, 95% CI -0.049 to -0.021/1000 AOBDs; p<0.001), a 29% fall in hospital-associated incidence density (-0.029, 95% CI -0.035 to -0.023/1000 AOBDs; p<0.001) and a 46% reduction in 30-day mortality (-15.6, 95% CI -24.1% to -7.1%; p<0.001). Positive associations with fluoroquinolone and cephalosporin use suggested that antibiotic stewardship reduced prevalence density of MRSA bacteraemia by 0.027 (95% CI 0.015 to 0.039)/1000 AOBDs. Rates of MSSA bacteraemia were not significantly affected by screening or antibiotic use.
Declining clinical burdens from SAB were attributable to reductions in MRSA infections. Universal admission screening and antibiotic stewardship were associated with decreases in MRSA bacteraemia and associated early mortality. Control of MSSA bacteraemia remains a priority.
BMJ Open 05/2012; 2(3). DOI:10.1136/bmjopen-2011-000797 · 2.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper focuses on antimicrobial stewardshipin human healthcare, and some concepts possibly transferable to veterinary medicine. Antimicrobial stewardship is a multidisciplinary effort to reduce antimicrobial resistance in human pathogens, when future drug development is dwindling. These strategies encourage healthcare staff to use antimicrobials prudently and, when needed, for as short a duration and with as narrow a spectrum as possible. Various methods are involved in stewardship within the healthcare setting, often implemented simultaneously, which sometimes makes evaluation of specific measures difficult. All healthcare workers must accept responsibility for stewardship, although the role of infectious diseases physicians, microbiologists, pharmacists and infection control practitioners is crucial, as are appropriate surveillance systems and information technology. Support from management and government is also beneficial. Considering the frequent use of antimicrobials in animals, it would seem sensible to apply a similarly critical approach to conserve the efficacy of the antimicrobials still available, now and in the future.
Revue scientifique et technique (International Office of Epizootics) 04/2012; 31(1):135-44. · 0.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study investigated "creep" in vancomycin and daptomycin MICs among methicillin-resistant Staphylococcus aureus (MRSA) isolates from blood cultures over a 5-year period in a hospital in the United Kingdom, using different susceptibility testing methods. Trends in vancomycin and daptomycin susceptibility were evaluated by using Etest performed prospectively on isolates in routine clinical practice from December 2007 to December 2010 (n = 102). Comparison was made to results from prospective testing of subcultures at the Scottish MRSA Reference Laboratory, using an automated system (Vitek 2) and retrospective testing (Etest and CLSI reference broth microdilution [BMD] method) of stored isolates from 2006 to 2010 (n = 208). Spearman's rank correlations revealed a significant increase in vancomycin MIC (P = 0.012) and a significant decrease in daptomycin MIC (P = 0.03) by year of study for Etest results from the time of isolation. However, neither trend was replicated in MICs from automated or retrospective testing. The Friedman test revealed a significant difference between vancomycin MICs obtained from the same samples by different testing methods (χ(2) [3 degrees of freedom] = 97; P < 0.001). MICs from automated testing and Etest analysis of stored isolates were significantly lower than those from Etest analysis at the time of isolation for both antibiotics (P < 0.001). Effects of storage on the MIC appeared within the first 6 months of storage. Inconsistent evidence on vancomycin MIC creep and the relevance of the MIC to clinical outcome may arise from differences in susceptibility testing methods, including storage of isolates. There is a need to standardize and streamline susceptibility testing of vancomycin against MRSA.
[Show abstract][Hide abstract] ABSTRACT: A multi-national working group on antibiotic stewardship, from the International Society of Chemotherapy, put together ten recommendations to physicians prescribing antibiotics to outpatients. These recommendations are: (1) use antibiotics only when needed; teach the patient how to manage symptoms of non-bacterial infections; (2) select the adequate ATB; precise targeting is better than shotgun therapy; (3) consider pharmacokinetics and pharmacodynamics when selecting an ATB; use the shortest ATB course that has proven clinical efficacy; (4) encourage patients' compliance; (5) use antibiotic combinations only in specific situations; (6) avoid low quality and sub-standard drugs; prevent prescription changes at the drugstore; (7) discourage self-prescription; (8) follow only evidence-based guidelines; beware those sponsored by drug companies; (9) rely (rationally) upon the clinical microbiology lab; and (10) prescribe ATB empirically - but intelligently; know local susceptibility trends, and also surveillance limitations.
Frontiers in Microbiology 11/2011; 2:230. DOI:10.3389/fmicb.2011.00230 · 3.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A Health Technology Assessment (HTA) model on effectiveness of meticillin-resistant Staphylococcus aureus (MRSA) screening in Scotland suggested that universal screening using chromogenic agar was the preferred option in terms of effectiveness and cost.
To test the model's validity through a one-year pilot-study.
A large one-year prospective cohort study of MRSA screening was carried out in six acute hospitals in NHS Scotland, incorporating 81,438 admissions. Outcomes (MRSA colonization and infection rates) were subjected to multivariable analyses, and trends before and after implementation of screening were compared.
The initial colonization prevalence of 5.5% decreased to 3.5% by month 12 of the study (P < 0.0001). Colonization was associated with the number of admissions per patient, specialty of admission, age, and source of admission (home, other hospital or care home). Around 2% of all admissions with no prior history of MRSA infection or colonization tested positive. Those who were screen positive on admission and not previously known positive were 12 times more likely than those who screened negative to develop infection, increasing to 18 times if they were both screen positive and previously known positive. MRSA infections (7.5 per 1000 inpatient-days overall) also reduced significantly over the study year (P = 0.0209).
The risk factors identified for colonization and infection indicate that a universal clinical risk assessment may have a role in MRSA screening.
The Journal of hospital infection 11/2011; 80(1):31-5. DOI:10.1016/j.jhin.2011.09.008 · 2.78 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To estimate the proportion of patients who acquire methicillin-resistant Staphylococcus aureus (MRSA) while in hospital and to identify risk factors associated with acquisition of MRSA.
Retrospective cohort study.
Adult patients discharged from 36 general specialty wards of 2 Scottish hospitals that had implemented universal screening for MRSA on admission.
Patients were screened for MRSA on discharge from hospital by using multisite body swabs that were tested by culture. Discharge screening results were linked to admission screening results. Genotyping was undertaken to identify newly acquired MRSA in MRSA-positive patients on admission.
Of the 5,155 patients screened for MRSA on discharge, 2.9% (95% confidence interval [CI], 2.43-3.34) were found to be positive. In the subcohort screened on both admission and discharge (n = 2,724), 1.3% of all patients acquired MRSA while in hospital (incidence rate, 2.1/1,000 hospital bed-days in this cohort [95% CI, 1.5-2.9]), while 1.3% remained MRSA positive throughout hospital stay. Three risk factors for acquisition of MRSA were identified: age above 64 years, self-reported renal failure, and self-reported presence of open wounds. On a population level, the prevalence of MRSA colonization did not differ between admission and discharge.
Cross-transmission of MRSA takes place in Scottish hospitals that have implemented universal screening for MRSA. This study reinforces the importance of infection prevention and control measures to prevent MRSA cross-transmission in hospitals; universal screening for MRSA on admission will in itself not be sufficient to reduce the number of MRSA colonizations and subsequent MRSA infections.
Infection Control and Hospital Epidemiology 09/2011; 32(9):889-96. DOI:10.1086/661280 · 3.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Candidaemia is associated with high mortality. Despite the fact that Candida species account for close to 10% of all nosocomial bloodstream infections, relatively few studies have investigated the management of candidaemia in hospitals. Our objective was to find out how candidaemia is managed in hospitals. Data relating to all episodes of candidaemia for the year 2008 were retrospectively collected in five centres in Scotland and Wales. A total of 96 candidaemic episodes were recorded in the year 2008, yielding 103 isolates of Candida. Fifty candidaemic episodes were caused by Candida albicans. Fluconazole was the most common agent prescribed for the treatment of candidaemia. There was great variation in the prescribed dose of fluconazole. Forty per cent of patients who survived received <2 weeks of systemic antifungal therapy. Central venous catheters (CVC) were removed in 57% of patients. CVC removal was not associated with better survival. The overall mortality was 40.4%. Management of candidaemia varies between the UK centres and is often inadequate. There is need to have consensus on the dosages of antifungal agents and the duration of therapy. The current guidance on removal of CVC in all cases of candidaemia should be reviewed.
[Show abstract][Hide abstract] ABSTRACT: This study explored strain distribution and resistance patterns of methicillin-resistant Staphylococcus aureus (MRSA) over a 5-year period in northeastern Scotland. We noted a shift in the relative rates of epidemic strains and an increase in community-associated strains. Use of oral antibiotics to eradicate throat carriage may have contributed to trimethoprim resistance, which was observed to increase 10-fold.
[Show abstract][Hide abstract] ABSTRACT: Clin Microbiol Infect 2010; 16: 1721–1728
Methicillin-resistant Staphylococcus aureus (MRSA) clones have caused a huge worldwide epidemic of hospital-acquired infections over the past 20–30 years and continue to evolve, including the advent of virulent community strains. The burden on healthcare services is highly significant, in particular because MRSA has not replaced susceptible staphylococcal infection but is an additional problem. Treatment strategies for MRSA are suboptimal and compromise the care of patients. MRSA is associated with serious morbidity and mortality, both within and without hospitals. Although the literature on the costs of MRSA and its control is suboptimal, it is clear that the control of MRSA is highly desirable and likely to be cost-effective. Any compromises in control are likely to be false economies.
[Show abstract][Hide abstract] ABSTRACT: Bacterial resistance to multiple antibiotics is a serious and emerging threat. Several measures have been proposed to curb this growing trend. These include prescribing restrictions, education, and infection control that target transmission, among several others. Antibiotic cycling has been a subject of debate, and although many investigators have studied the utility of antibiotic cycling with the help of theoretical models or as part of clinical investigations, several areas remain undefined and unclear. This review summarizes the available information on antibiotic heterogeneity (antibiotic cycling, antibiotic mixing, and other types of antibiotic protocols) with a critical analysis of the published studies.
Annals of the New York Academy of Sciences 12/2010; 1213(1):81-91. DOI:10.1111/j.1749-6632.2010.05867.x · 4.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Global changes in antibiotic production and use patterns, in synergy with climate change, suggest that antibiotic resistance will only increase. When combined with the crisis in new drug development, antibiotic stewardship becomes ever more important in order to preserve the activity of these unique drugs.
International journal of antimicrobial agents 11/2010; 36 Suppl 3:S1-2. DOI:10.1016/S0924-8579(10)00497-8 · 4.26 Impact Factor