Clinafloxacin versus piperacillin-tazobactam in treatment of patients with severe skin and soft tissue infections

Brazilian Society of Angiology and Vascular Surgery 2023 guidelines on the diabetic foot

The diabetic foot interacts with anatomical, vascular, and neurological factors that challenge clinical practice. This study aimed to compile the primary scientific evidence based on a review of the main guidelines, in addition to articles published on the Embase, Lilacs, and PubMed platforms. The European Society of Cardiology system was used to develop recommendation classes and levels of evidence. The themes were divided into six chapters (Chapter 1 - Prevention of foot ulcers in people with diabetes; Chapter 2 - Pressure relief from foot ulcers in people with diabetes; Chapter 3 -Classifications of diabetic foot ulcers; Chapter 4 - Foot and peripheral artery disease; Chapter 5 - Infection and the diabetic foot; Chapter 6 - Charcot's neuroarthropathy). This version of the Diabetic Foot Guidelines presents essential recommendations for the prevention, diagnosis, treatment, and follow-up of patients with diabetic foot, offering an objective guide for medical practice.

Clinical practice recommendations for infectious disease management of diabetic foot infection (DFI) - 2023 SPILF

In march 2020, the International Working Group on the Diabetic Foot (IWGDF) published an update of the 2015 guidelines on the diagnosis and management of diabetic foot infection (DFI). While we (the French ID society, SPILF) endorsed some of these recommendations, we wanted to update our own 2006 guidelines and specifically provide informative elements on modalities of microbiological diagnosis and antibiotic treatment (especially first- and second-line regiments, oral switch and duration). The recommendations put forward in the present guidelines are addressed to healthcare professionals managing patients with DFI and more specifically focused on infectious disease management of this type of infection, which clearly needs a multidisciplinary approach. Staging of the severity of the infection is mandatory using the classification drawn up by the IWGDF. Microbiological samples should be taken only in the event of clinical signs suggesting infection in accordance with a strict preliminarily established protocol. Empirical antibiotic therapy should be chosen according to the IWGDF grade of infection and duration of the wound, but must always cover methicillin-sensitive Staphylococcus aureus. Early reevaluation of the patient is a fundamental step, and duration of antibiotic therapy can be shortened in many situations. When osteomyelitis is suspected, standard foot radiograph is the first-line imagery examination and a bone biopsy should be performed for microbiological documentation. Histological analysis of the bone sample is no longer recommended. High dosages of antibiotics are recommended in cases of confirmed osteomyelitis.

Systemic Antimicrobial Therapy for Diabetic Foot Infections: An Overview of Systematic Reviews

Diabetic foot infections (DFIs) are a common complication of diabetes; however, there is clinical uncertainty regarding the optimal antimicrobial selection. The aim of this review was to critically evaluate the recent systematic reviews on the efficacy and safety of systemic (parenteral or oral) antimicrobials for DFI. Medline, Embase, CENTRAL, and CINAHL databases and the PROSPERO register were searched from January 2015 to January 2023. Systematic reviews with or without meta-analyses on systemic antimicrobials for DFI, with outcomes of clinical infection resolution or complications, were included. Of the 413 records identified, 6 systematic reviews of 29 individual studies were included. Heterogeneity of individual studies precluded meta-analysis, except for ertapenem versus piperacillin-tazobactam (RR 1.07, 95% CI [0.96-1.19]) and fluoroquinolones versus piperacillin-tazobactam (RR 1.03, 95% CI [0.89-1.20]) in one review. The application of the AMSTAR-2 tool determined two reviews to be of high quality. There was no statistical difference in the clinical resolution of infections for 24 different antimicrobial regimens (penicillins, cephalosporins, carbapenems, fluoroquinolones, vancomycin, metronidazole, clindamycin, linezolid, daptomycin, and tigecycline). However, tigecycline did not meet non-inferiority against ertapenem ± vancomycin (absolute difference -5.5%, 95% CI [-11.0-0.1]) and was associated with a higher incidence of adverse drug events. There is minimal systematic review evidence to suggest one regimen is superior to another for DFI.

Beta-Lactam vs. Fluoroquinolone Monotherapy for Pseudomonas aeruginosa Infection: A Systematic Review and Meta-Analysis

Introduction: Pseudomonas aeruginosa (PA) is a leading cause of healthcare-associated infections. A variety of antibiotic classes are used in the treatment of PA infections, including beta-lactams (BLs) and fluoroquinolones (FQs), given either together in combination therapy or alone in monotherapy. A systematic review and meta-analysis were performed to evaluate the therapeutic efficacy of BL agents versus FQ agents as active, definitive monotherapy in PA infections in adults. Methods: Comprehensive literature searches of the Medline and Scopus electronic databases, alongside hand searches of the Cochrane Database of Systematic Reviews, PubMed, and Google Scholar, were performed without a time restriction to identify studies published in English comparing BL and FQ agents given as monotherapy for PA infection in hospitalized adults for which mortality, bacteriological eradication, or clinical response was evaluated. One reviewer screened search results based on pre-defined selection criteria. Two reviewers independently assessed included studies for methodological quality using NIH assessment tools. Two fixed-effects meta-analyses were performed. Results: A total of 368 articles were screened, and six studies involving 338 total patients were included in the meta-analysis. Upon evaluation of methodological quality, two studies were rated good, three fair, and one poor. A meta-analysis of three studies demonstrates FQ monotherapy is associated with significantly improved survival compared to BL monotherapy for patients with PA bacteremia (OR, 3.65; 95% CI, 1.27–10.44; p = 0.02). A meta-analysis of three studies demonstrates FQ monotherapy is associated with equivalent bacteriological eradication compared to BL monotherapy for PA pneumonia or skin and soft tissue infection (RD, 0.07; 95% CI, −0.09 to 0.24; p = 0.39). Conclusion: The meta-analyses demonstrate FQ monotherapy significantly improves survival in PA bacteremia and is associated with similar rates of bacteriological eradication in pneumonia and skin and soft tissue infection caused by PA compared to BL monotherapy. However, more research is needed to make meaningful clinical recommendations.

Interventions in the management of infection in the foot in diabetes: a systematic review

The optimal approaches to managing diabetic foot infections remain a challenge for clinicians. Despite an exponential rise in publications investigating different treatment strategies, the various agents studied generally produce comparable results, and high-quality data are scarce. In this systematic review, we searched the medical literature using the PubMed and Embase databases for published studies on the treatment of diabetic foot infections as of June 2018. This systematic review is an update of previous reviews, the first of which was undertaken in 2010 and the most recent in 2014, by the infection committee of the International Working Group of the Diabetic Foot. We defined the context of literature by formulating clinical questions of interest, then developing structured clinical questions (PICOs) to address these. We only included data from controlled studies of an intervention to prevent or cure a diabetic foot infection. Two independent reviewers selected articles for inclusion and then assessed their relevant outcomes and the methodological quality. Our literature search identified a total of 15 327 articles, of which we selected 48 for full-text review; we added five more studies discovered by means other than the systematic literature search. Among these selected articles were 11 high-quality studies published in the last 4 years and two Cochrane systematic reviews. Overall, the outcomes in patients treated with the different antibiotic regimens for both skin and soft tissue infection and osteomyelitis of the diabetic foot were broadly equivalent across studies, except that treatment with tigecycline was inferior to ertapenem (±vancomycin). Similar outcomes were also reported in studies comparing primarily surgical and predominantly antibiotic treatment strategies in selected patients with diabetic foot osteomyelitis. There is insufficient high-quality evidence to assess the effect of various adjunctive therapies, such as negative pressure wound therapy, topical ointments or hyperbaric oxygen, on infection related outcomes of the diabetic foot. In general, the quality of more recent trial designs are better in past years, but there is still a great need for further well-designed trials to produce higher quality evidence to underpin our recommendations.

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis and treatment of foot infection in persons with diabetes and updates the 2015 IWGDF infection guideline. On the basis of patient, intervention, comparison, outcomes (PICOs) developed by the infection committee, in conjunction with internal and external reviewers and consultants, and on systematic reviews the committee conducted on the diagnosis of infection (new) and treatment of infection (updated from 2015), we offer 27 recommendations. These cover various aspects of diagnosing soft tissue and bone infection, including the classification scheme for diagnosing infection and its severity. Of note, we have updated this scheme for the first time since we developed it 15 years ago. We also review the microbiology of diabetic foot infections, including how to collect samples and to process them to identify causative pathogens. Finally, we discuss the approach to treating diabetic foot infections, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and for bone infections, when and how to approach surgical treatment, and which adjunctive treatments we think are or are not useful for the infectious aspects of diabetic foot problems. For this version of the guideline, we also updated four tables and one figure from the 2016 guideline. We think that following the principles of diagnosing and treating diabetic foot infections outlined in this guideline can help clinicians to provide better care for these patients.

A case study of venous leg ulceration

Venous ulcers or stasis ulcers account for 80% of lower extremity ulcerations. Approximately 1-2% of the population will suffer from the chronic debilitating condition, with chronic venous insufficiency affecting up to 50% of the adult population. There are many methods of treatment and common treatments include conventional, surgical or mechanical methods. This article examines the complications of leg ulcer management, with the emphasis on the use of antibiotics. The case study demonstrates the positive impact self-care can have as part of a treatment plan.

Clinical efficacy of piperacillin/tazobactam in the treatment of complicated skin and soft tissue infections

INTRODUCTION

Complicated skin and soft tissue infections (cSSTIs) are skin and soft tissue infections (SSTIs) that involve deep soft tissue. cSSTIs often require surgical intervention and/or hospitalization. cSSTIs are associated with significant mortality and morbidity, and carry a significant burden on health care systems. Piperacillin/tazobactam has been regarded as a standard treatment for cSSTIs because of its antibiotic spectrum, safety and clinical efficacy. Several antibiotics, as compared to piperacillin/tazobactam, have been evaluated in the treatment of cSSTIs. Areas covered: This review summarizes randomized controlled trials (RCTs) evaluating the clinical efficacy of piperacillin/tazobactam for the treatment of cSSTIs. Expert opinion: Piperacillin/tazobactam, which covers most causative organisms in cSSTIs, is the drug of choice for the treatment of cSSTIs. Other options such as ertapenem and moxifloxacin may be reasonable where multiple daily dosing or intravenous administration is inappropriate. But in general, they should be avoided as an empirical treatment because of their highly association with resistant bacteria, which are becoming a global threat. Therefore, piperacilin/tazobactam is appropriate as an empirical therapy for the treatment of SSTIs and should be de-escalated as soon as causative organisms are identified, their drug-sensitivity results are available, and clinical condition becomes stable.

Clostridium difficile infection following systemic antibiotic administration in randomised controlled trials: a systematic review and meta-analysis

Antibiotics have been the most important risk factor for Clostridium difficile infection (CDI). However, only data from non-randomised studies have been reviewed. We sought to evaluate the risk for development of CDI associated with the major antibiotic classes by analysing data from randomised controlled trials (RCTs). The PubMed, Cochrane and Scopus databases were searched and the references of selected RCTs were also hand-searched. Eligible studies should have compared only one antibiotic versus another administered systemically. Inclusion of studies comparing combinations of antibiotics was allowed only if the second antibiotic was the same or from the same class or if it was administered in a subset of the enrolled patients who were equally distributed in the two arms. Only a minority of the selected RCTs (79/1332; 5.9%) reported CDI episodes. Carbapenems were associated with more CDI episodes than fluoroquinolones [risk ratio (RR) = 2.44, 95% confidence interval (CI) 1.32-4.49] and cephalosporins (RR = 2.24, 95% CI 1.46-3.42), but not penicillins (RR = 2.53, 95% CI 0.87-7.41). Cephalosporins were associated with more CDIs than penicillins (RR = 2.36, 95% CI 1.32-4.23) and fluoroquinolones (RR = 2.84, 95% CI 1.60-5.06). There was no difference in CDI frequency between fluoroquinolones and penicillins (RR = 1.34, 95% CI 0.55-3.25). Finally, clindamycin was associated with more CDI episodes than cephalosporins and penicillins (RR = 3.92, 95% CI 1.15-13.43). In conclusion, data from RCTs showed that clindamycin and carbapenems were associated with more CDIs than other antibiotics.

Clinafloxacin for Treatment of Burkholderia cenocepacia Infection in a Cystic Fibrosis Patient

Respiratory infection with Burkholderia cenocepacia is associated with accelerated decline in lung function and increased mortality in cystic fibrosis (CF) patients (A. M. Jones, M. E. Dodd, J. R. W. Govan, V. Barcus, C. J. Doherty, J. Morris, and A. K. Webb, Thorax 59:948-951, 2004, http://dx.doi.org/10.1136/thx.2003.017210). B. cenocepacia often possesses innate resistance to multiple antimicrobial classes, making eradication uncommon in established infection (P. B. Davis, Am J Respir Crit Care Med 173:475-482, 2006, http://dx.doi.org/10.1164/rccm.200505-840OE). We report the use of clinafloxacin in a CF patient with advanced B. cenocepacia infection, present pharmacokinetic (PK) data, and discuss the potential therapeutic role of clinafloxacin in patients with this condition.

Clinafloxacin for Treatment of Burkholderia cenocepacia Infection in a Cystic Fibrosis Patient

Respiratory infection with Burkholderia cenocepacia is associated with accelerated decline in lung function and increased mortality in cystic fibrosis (CF) patients (A. M. Jones, M. E. Dodd, J. R. W. Govan, V. Barcus, C. J. Doherty, J. Morris, and A. K. Webb, Thorax 59:948-951, 2004, http://dx.doi.org/10.1136/thx.2003.017210). B. cenocepacia often possesses innate resistance to multiple antimicrobial classes, making eradication uncommon in established infection (P. B. Davis, Am J Respir Crit Care Med 173:475-482, 2006, http://dx.doi.org/10.1164/rccm.200505-840OE). We report the use of clinafloxacin in a CF patient with advanced B. cenocepacia infection, present pharmacokinetic (PK) data, and discuss the potential therapeutic role of clinafloxacin in patients with this condition.

Interventions in the management of infection in the foot in diabetes: a systematic review

The expert panel on diabetic foot infection (DFI) of the International Working Group on the Diabetic Foot conducted a systematic review seeking all published reports relating to any type of treatment for infection of the foot in persons with diabetes published as of 30 June 2014. This review, conducted with both PubMed and EMBASE, was used to update an earlier one undertaken on 30 June 2010 using the same search string. Eligible publications included those that had outcome measures reported for both a treated and a control population that were managed either at the same time, or as part of a before-and-after case design. We did not include studies that contained only information related to definition or diagnosis, but not treatment, of DFI. The current search identified just seven new articles meeting our criteria that were published since the 33 identified with the previous search, making a total of 40 articles from the world literature. The identified articles included 37 randomised controlled trials (RCTs) and three cohort studies with concurrent controls, and included studies on the use of surgical procedures, topical antiseptics, negative pressure wound therapy and hyperbaric oxygen. Among the studies were 15 RCTs that compared outcomes of treatment with new antibiotic preparations compared with a conventional therapy in the management of skin and soft tissue infection. In addition, 10 RCTs and 1 cohort study compared different treatments for osteomyelitis in the diabetic foot. Results of comparisons of different antibiotic regimens generally demonstrated that newly introduced antibiotic regimens appeared to be as effective as conventional therapy (and also more cost-effective in one study), but one study failed to demonstrate non-inferiority of a new antibiotic compared with that of a standard agent. Overall, the available literature was both limited in both the number of studies and the quality of their design. Thus, our systematic review revealed little evidence upon which to make recommendations for treatment of DFIs. There is a great need for further well-designed trials that will provide robust data upon which to make decisions about the most appropriate treatment of both skin and soft tissue infection and osteomyelitis in diabetic patients.

Isolation and Antibiotic Susceptibility of the Microorganisms Isolated from Diabetic Foot Infections in Nemazee Hospital, Southern Iran

Background. Diabetic foot infections (DFIs) are a major public health issue and identification of the microorganisms causing such polymicrobial infections is useful to find out appropriate antibiotic therapy. Meanwhile, many reports have shown antibiotic resistance rising dramatically. In the present study, we sought to determine the prevalence of microorganisms detected on culture in complicated DFIs in hospitalized patients and their antibiotic sensitivity profiles. Methods. A cross-sectional study was conducted for a period of 24 months from 2012 to 2014 in Nemazee Hospital, Shiraz, Iran. The demographic and clinical features of the patients were obtained. Antimicrobial susceptibility testing to different agents was carried out using the disc diffusion method. Results. During this period, 122 aerobic microorganisms were isolated from DFIs. Among Gram-positive and Gram-negative bacteria, Staphylococcus spp. and E. coli were the most frequent organisms isolated, respectively. Of the isolates, 91% were multidrug while 78% of S. aureus isolates were methicillin resistant. 53% of Gram-negative bacteria were positive for extended-spectrum β-lactamase. Conclusion. Given the involvement of different microorganisms and emergence of multidrug resistant strains, clinicians are advised to consider culture before initiation of empirical therapy.

Systemic antibiotics for treating diabetic foot infections

BACKGROUND

Foot infection is the most common cause of non-traumatic amputation in people with diabetes. Most diabetic foot infections (DFIs) require systemic antibiotic therapy and the initial choice is usually empirical. Although there are many antibiotics available, uncertainty exists about which is the best for treating DFIs.

OBJECTIVES

To determine the effects and safety of systemic antibiotics in the treatment of DFIs compared with other systemic antibiotics, topical foot care or placebo.

SEARCH METHODS

In April 2015 we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library); Ovid MEDLINE, Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE, and EBSCO CINAHL. We also searched in the Database of Abstracts of Reviews of Effects (DARE; The Cochrane Library), the Health Technology Assessment database (HTA; The Cochrane Library), the National Health Service Economic Evaluation Database (NHS-EED; The Cochrane Library), unpublished literature in OpenSIGLE and ProQuest Dissertations and on-going trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating the effects of systemic antibiotics (oral or parenteral) in people with a DFI. Primary outcomes were clinical resolution of the infection, time to its resolution, complications and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the risk of bias, and extracted data. Risk ratios (RR) were estimated for dichotomous data and, when sufficient numbers of comparable trials were available, trials were pooled in a meta-analysis.

MAIN RESULTS

We included 20 trials with 3791 participants. Studies were heterogenous in study design, population, antibiotic regimens, and outcomes. We grouped the sixteen different antibiotic agents studied into six categories: 1) anti-pseudomonal penicillins (three trials); 2) broad-spectrum penicillins (one trial); 3) cephalosporins (two trials); 4) carbapenems (four trials); 5) fluoroquinolones (six trials); 6) other antibiotics (four trials).Only 9 of the 20 trials protected against detection bias with blinded outcome assessment. Only one-third of the trials provided enough information to enable a judgement about whether the randomisation sequence was adequately concealed. Eighteen out of 20 trials received funding from pharmaceutical industry-sponsors.The included studies reported the following findings for clinical resolution of infection: there is evidence from one large trial at low risk of bias that patients receiving ertapenem with or without vancomycin are more likely to have resolution of their foot infection than those receiving tigecycline (RR 0.92, 95% confidence interval (CI) 0.85 to 0.99; 955 participants). It is unclear if there is a difference in rates of clinical resolution of infection between: 1) two alternative anti-pseudomonal penicillins (one trial); 2) an anti-pseudomonal penicillin and a broad-spectrum penicillin (one trial) or a carbapenem (one trial); 3) a broad-spectrum penicillin and a second-generation cephalosporin (one trial); 4) cephalosporins and other beta-lactam antibiotics (two trials); 5) carbapenems and anti-pseudomonal penicillins or broad-spectrum penicillins (four trials); 6) fluoroquinolones and anti-pseudomonal penicillins (four trials) or broad-spectrum penicillins (two trials); 7) daptomycin and vancomycin (one trial); 8) linezolid and a combination of aminopenicillins and beta-lactamase inhibitors (one trial); and 9) clindamycin and cephalexin (one trial).Carbapenems combined with anti-pseudomonal agents produced fewer adverse effects than anti-pseudomonal penicillins (RR 0.27, 95% CI 0.09 to 0.84; 1 trial). An additional trial did not find significant differences in the rate of adverse events between a carbapenem alone and an anti-pseudomonal penicillin, but the rate of diarrhoea was lower for participants treated with a carbapenem (RR 0.58, 95% CI 0.36 to 0.93; 1 trial). Daptomycin produced fewer adverse effects than vancomycin or other semi-synthetic penicillins (RR 0.61, 95%CI 0.39 to 0.94; 1 trial). Linezolid produced more adverse effects than ampicillin-sulbactam (RR 2.66; 95% CI 1.49 to 4.73; 1 trial), as did tigecycline compared to ertapenem with or without vancomycin (RR 1.47, 95% CI 1.34 to 1.60; 1 trial). There was no evidence of a difference in safety for the other comparisons.

AUTHORS' CONCLUSIONS

The evidence for the relative effects of different systemic antibiotics for the treatment of foot infections in diabetes is very heterogeneous and generally at unclear or high risk of bias. Consequently it is not clear if any one systemic antibiotic treatment is better than others in resolving infection or in terms of safety. One non-inferiority trial suggested that ertapenem with or without vancomycin is more effective in achieving clinical resolution of infection than tigecycline. Otherwise the relative effects of different antibiotics are unclear. The quality of the evidence is low due to limitations in the design of the included trials and important differences between them in terms of the diversity of antibiotics assessed, duration of treatments, and time points at which outcomes were assessed. Any further studies in this area should have a blinded assessment of outcomes, use standardised criteria to classify severity of infection, define clear outcome measures, and establish the duration of treatment.

Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) in non surgical wounds

BACKGROUND

Non surgical wounds include chronic ulcers (pressure or decubitus ulcers, venous ulcers, diabetic ulcers, ischaemic ulcers), burns and traumatic wounds. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonisation (i.e. presence of MRSA in the absence of clinical features of infection such as redness or pus discharge) or infection in chronic ulcers varies between 7% and 30%. MRSA colonisation or infection of non surgical wounds can result in MRSA bacteraemia (infection of the blood) which is associated with a 30-day mortality of about 28% to 38% and a one-year mortality of about 55%. People with non surgical wounds colonised or infected with MRSA may be reservoirs of MRSA, so it is important to treat them, however, we do not know the optimal antibiotic regimen to use in these cases.

OBJECTIVES

To compare the benefits (such as decreased mortality and improved quality of life) and harms (such as adverse events related to antibiotic use) of all antibiotic treatments in people with non surgical wounds with established colonisation or infection caused by MRSA.

SEARCH METHODS

We searched the following databases: The Cochrane Wounds Group Specialised Register (searched 13 March 2013); The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2); Database of Abstracts of Reviews of Effects (2013, Issue 2); NHS Economic Evaluation Database (2013, Issue 2); Ovid MEDLINE (1946 to February Week 4 2013); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, March 12, 2013); Ovid EMBASE (1974 to 2013 Week 10); EBSCO CINAHL (1982 to 8 March 2013).

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) comparing antibiotic treatment with no antibiotic treatment or with another antibiotic regimen for the treatment of MRSA-infected non surgical wounds. We included all relevant RCTs in the analysis, irrespective of language, publication status, publication year, or sample size.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials, and extracted data from the trial reports. We calculated the risk ratio (RR) with 95% confidence intervals (CI) for comparing the binary outcomes between the groups and planned to calculate the mean difference (MD) with 95% CI for comparing the continuous outcomes. We planned to perform the meta-analysis using both fixed-effect and random-effects models. We performed intention-to-treat analysis whenever possible.

MAIN RESULTS

We identified three trials that met the inclusion criteria for this review. In these, a total of 47 people with MRSA-positive diabetic foot infections were randomised to six different antibiotic regimens. While these trials included 925 people with multiple pathogens, they reported the information on outcomes for people with MRSA infections separately (MRSA prevalence: 5.1%). The only outcome reported for people with MRSA infection in these trials was the eradication of MRSA. The three trials did not report the review's primary outcomes (death and quality of life) and secondary outcomes (length of hospital stay, use of healthcare resources and time to complete wound healing). Two trials reported serious adverse events in people with infection due to any type of bacteria (i.e. not just MRSA infections), so the proportion of patients with serious adverse events was not available for MRSA-infected wounds. Overall, MRSA was eradicated in 31/47 (66%) of the people included in the three trials, but there were no significant differences in the proportion of people in whom MRSA was eradicated in any of the comparisons, as shown below.1. Daptomycin compared with vancomycin or semisynthetic penicillin: RR of MRSA eradication 1.13; 95% CI 0.56 to 2.25 (14 people).2. Ertapenem compared with piperacillin/tazobactam: RR of MRSA eradication 0.71; 95% CI 0.06 to 9.10 (10 people).3. Moxifloxacin compared with piperacillin/tazobactam followed by amoxycillin/clavulanate: RR of MRSA eradication 0.87; 95% CI 0.56 to 1.36 (23 people).

AUTHORS' CONCLUSIONS

We found no trials comparing the use of antibiotics with no antibiotic for treating MRSA-colonised non-surgical wounds and therefore can draw no conclusions for this population. In the trials that compared different antibiotics for treating MRSA-infected non surgical wounds, there was no evidence that any one antibiotic was better than the others. Further well-designed RCTs are necessary.

Diagnostics and treatment of the diabetic foot

Every 30 s, a lower limb is amputated due to diabetes. Of all amputations in diabetic patients 85% are preceded by a foot ulcer which subsequently deteriorates to a severe infection or gangrene. There is a complexity of factors related to healing of foot ulcers including strategies for treatment of decreased perfusion, oedema, pain, infection, metabolic disturbances, malnutrition, non-weight bearing, wound treatment, foot surgery, and management of intercurrent disease. Patients with diabetic foot ulcer and decreased perfusion do often not have rest pain or claudication and as a consequence non-invasive vascular testing is recommended for early recognition of ulcers in need of revascularisation to achieve healing. A diabetic foot infection is a potentially limb-threatening condition. Infection is diagnosed by the presence or increased rate of signs inflammation. Often these signs are less marked than expected. Imaging studies can diagnose or better define deep, soft tissue purulent collections and are frequently needed to detect pathological findings in bone. The initial antimicrobial treatment as well as duration of treatment is empiric. There is a substantial delay in wound healing in diabetic foot ulcer which has been related to various abnormalities. Several new treatments related to these abnormalities have been explored in wound healing with various successes. An essential part of the strategy to achieve healing is an effective offloading. Many interventions with advanced wound management have failed due to not recognizing the need for effective offloading. A multidisciplinary approach to wounds and foot ulcer has been successfully implemented in different centres with a substantial decrease in amputation rate.

A systematic review of the effectiveness of interventions in the management of infection in the diabetic foot

The International Working Group on the Diabetic Foot expert panel on infection conducted a systematic review of the published evidence relating to treatment of foot infection in diabetes. Our search of the literature published prior to August 2010 identified 7517 articles, 29 of which fulfilled predefined criteria for detailed data extraction. Four additional eligible papers were identified from other sources. Of the total of 33 studies, 29 were randomized controlled trials, and four were cohort studies. Among 12 studies comparing different antibiotic regimens in the management of skin and soft-tissue infection, none reported a better response with any particular regimen. Of seven studies that compared antibiotic regimens in patients with infection involving both soft tissue and bone, one reported a better clinical outcome in those treated with cefoxitin compared with ampicillin/sulbactam, but the others reported no differences between treatment regimens. In two health economic analyses, there was a small saving using one regimen versus another. No published data support the superiority of any particular route of delivery of systemic antibiotics or clarify the optimal duration of antibiotic therapy in either soft-tissue infection or osteomyelitis. In one non-randomized cohort study, the outcome of treatment of osteomyelitis was better when the antibiotic choice was based on culture of bone specimens as opposed to wound swabs, but this study was not randomized, and the results may have been affected by confounding factors. Results from two studies suggested that early surgical intervention was associated with a significant reduction in major amputation, but the methodological quality of both was low. In two studies, the use of superoxidized water was associated with a better outcome than soap or povidone iodine, but both had a high risk of bias. Studies using granulocyte-colony stimulating factor reported mixed results. There was no improvement in infection outcomes associated with hyperbaric oxygen therapy. No benefit has been reported with any other intervention, and, overall, there are currently no trial data to justify the adoption of any particular therapeutic approach in diabetic patients with infection of either soft tissue or bone of the foot.

Interventions for cellulitis and erysipelas

BACKGROUND

Cellulitis and erysipelas are now usually considered manifestations of the same condition, a skin infection associated with severe pain and systemic symptoms. A range of antibiotic treatments are suggested in guidelines.

OBJECTIVES

To assess the efficacy and safety of interventions for non-surgically-acquired cellulitis.

SEARCH STRATEGY

In May 2010 we searched for randomised controlled trials in the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and the ongoing trials databases.

SELECTION CRITERIA

We selected randomised controlled trials comparing two or more different interventions for cellulitis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included 25 studies with a total of 2488 participants. Our primary outcome 'symptoms rated by participant or medical practitioner or proportion symptom-free' was commonly reported. No two trials examined the same drugs, therefore we grouped similar types of drugs together.Macrolides/streptogramins were found to be more effective than penicillin antibiotics (Risk ratio (RR) 0.84, 95% CI 0.73 to 0.97). In 3 trials involving 419 people, 2 of these studies used oral macrolide against intravenous (iv) penicillin demonstrating that oral therapies can be more effective than iv therapies (RR 0.85, 95% CI 0.73 to 0.98).Three studies with a total of 88 people comparing a penicillin with a cephalosporin showed no difference in treatment effect (RR 0.99, 95% CI 0.68 to 1.43).Six trials which included 538 people that compared different generations of cephalosporin, showed no difference in treatment effect (RR 1.00, 95% CI 0.94 to1.06).We found only small single studies for duration of antibiotic treatment, intramuscular versus intravenous route, the addition of corticosteroid to antibiotic treatment compared with antibiotic alone, and vibration therapy, so there was insufficient evidence to form conclusions. Only two studies investigated treatments for severe cellulitis and these selected different antibiotics for their comparisons, so we cannot make firm conclusions.

AUTHORS' CONCLUSIONS

We cannot define the best treatment for cellulitis and most recommendations are made on single trials. There is a need for trials to evaluate the efficacy of oral antibiotics against intravenous antibiotics in the community setting as there are service implications for cost and comfort.

Synergy between gemifloxacin and trimethoprim/sulfamethoxazole against community-associated methicillin-resistant Staphylococcus aureus

OBJECTIVES

The rapid emergence of methicillin-resistant Staphylococcus aureus from the community (CA-MRSA) presents difficulties in making treatment choices. We evaluated whether combining another orally available agent commonly used to treat CA-MRSA with gemifloxacin would enhance gemifloxacin activity against CA-MRSA.

METHODS

Fifty strains of SCCmec IV, agr group 1, Panton-Valentine leucocidin-positive CA-MRSA were evaluated for susceptibilities to gemifloxacin, trimethoprim/sulfamethoxazole, doxycycline, levofloxacin, rifampicin, clindamycin and erythromycin. Twenty of these strains were evaluated for the potential for synergy between gemifloxacin and trimethoprim/sulfamethoxazole, clindamycin and rifampicin by time-kill analysis. Two strains were further evaluated in an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model.

RESULTS

In time-kill analyses, gemifloxacin combined with trimethoprim/sulfamethoxazole produced additivity (6/20) or synergy (11/20) in 85% of the isolates tested. The addition of clindamycin to gemifloxacin showed additivity (3/20) or synergy (2/20) in 25% of the isolates. All isolates displayed indifference to the combination of gemifloxacin and rifampicin. In the PK/PD model, combining gemifloxacin and trimethoprim/sulfamethoxazole provided potent and sustained bactericidal activity to detection limits of 2 log(10) cfu/mL by 48 h; gemifloxacin combined with clindamycin or with rifampicin killed to detection limits by 56 h or later. One isolate developed efflux-mediated resistance to gemifloxacin at 96 h with gemifloxacin monotherapy. All combinations prevented the emergence of this resistance.

CONCLUSIONS

Synergy or additivity was demonstrated by time-kill analysis between gemifloxacin and trimethoprim/sulfamethoxazole in most isolates tested. In the PK/PD model, the addition of trimethoprim/sulfamethoxazole, clindamycin and rifampicin enhanced the activity of gemifloxacin against CA-MRSA and suppressed the emergence of resistance to gemifloxacin.

Factors associated with treatment failure in patients with diabetic foot infections: An analysis of data from randomized controlled trials

BACKGROUND

Although several antibiotics have been studied for the treatment of foot infections, their effectiveness has been considered to be similar. The scope of this analysis was the identification of factors that are associated with treatment failure based on evidence from randomized controlled trials (RCTs).

METHODS

Two reviewers independently extracted data from published RCTs comparing different antibiotics for diabetic foot infections (DFIs).

RESULTS

The combined observed treatment failure was 22.7% in the 18 RCTs included in the analysis. When different regimens of various antibiotics (penicillins, carbapenems, cephalosporins, and fluoroquinolones) were directly compared in the individual RCTs, they were associated with similar frequency of treatment failure. However, when all patients were combined, carbapenems were associated with fewer treatment failures. Also, treatment failure in patients with DFIs from whom methicillin-resistant S. aureus (MRSA) alone or as part of a polymicrobial infection was isolated was more common than in patients from whom other bacteria were isolated [24/68 (35.3%) versus 350/1522 (23%), p=0.02]. Among patients with DFIs due to MRSA the use of linezolid was not associated with better effectiveness in comparison to other antibiotics [treatment failure: 6/19 (31.6%) versus 18/49 (36.7%), p=0.69]. Of interest, treatment failure was similar in patients with and without osteomyelitis [44/169 (26.5%) versus 330/1424 (23.2%), p=0.34].

CONCLUSIONS

The isolation of MRSA seems to be a significant factor associated with treatment failure in patients with DFIs. Further research efforts are needed for the identification of additional risk factors for treatment failure and optimization of the management of patients with DFIs.

Piperacillin-tazobactam: a beta-lactam/beta-lactamase inhibitor combination

Piperacillin-tazobactam is a beta-lactam/beta-lactamase inhibitor combination with a broad spectrum of antibacterial activity that includes Gram-positive and -negative aerobic and anaerobic bacteria. Piperacillin-tazobactam retains its in vitro activity against broad-spectrum beta-lactamase-producing and some extended-spectrum beta-lactamase-producing Enterobacteriaceae, but not against isolates of Gram-negative bacilli harboring AmpC beta-lactamases. Piperacillin-tazobactam has recently been reformulated to include ethylenediaminetetraacetic acid and sodium citrate; this new formulation has been shown to be compatible in vitro with the two aminoglycosides, gentamicin and amikacin, allowing for simultaneous Y-site infusion, but not with tobramycin. Multicenter, randomized, double-blinded clinical trials have demonstrated piperacillin-tazobactam to be as clinically effective as relevant comparator antibiotics. Clinical trials have demonstrated piperacillin-tazobactam to be effective for the treatment of patients with intra-abdominal infections, skin and soft tissue infections, lower respiratory tract infections, complicated urinary tract infections, gynecological infections and more recently, febrile neutropenia. Piperacillin-tazobactam has an excellent safety and tolerability profile and continues to be a reliable option for the empiric treatment of moderate-to-severe infections in hospitalized patients.

Fluoroquinolones vs beta-lactams for empirical treatment of immunocompetent patients with skin and soft tissue infections: a meta-analysis of randomized controlled trials

OBJECTIVE

To compare the effectiveness and safety of fluoroquinolones with beta-lactams in the treatment of patients with skin and soft tissue infections (SSTIs).

METHODS

We searched the PubMed database, Cochrane Database of Controlled Trials, and references of relevant articles for study reports published between January 1980 and February 2006.

RESULTS

Twenty randomized controlled trials that enrolled 4817 patients were included in the analysis. Fluoroquinolones as empirical treatment of patients with SSTIs were more effective than beta-lactams for the clinically evaluable patients (90.4% vs 88.2%; odds ratio [OR], 1.29; 95% confidence interval [CI], 1.00-1.66). This was also true in subset analyses of randomized controlled trials that studied ciprofloxacin (OR, 2.49; 95% CI, 1.45-4.26) and for patients with mild to moderate infections (OR, 1.83; 95% CI, 1.13-2.96). In contrast, no difference was found between the compared regimens for patients with moderate to severe infections (OR, 1.12; 95% CI, 0.80-1.55), for patients who did not receive third-generation cephalosporins as the comparator antibiotic (OR, 0.99; 95% CI, 0.73-1.34), or for the microbiologically evaluable patients (OR, 1.19; 95% CI, 0.89-1.59). Fluoroquinolones were also associated with more adverse effects (19.2% vs 15.2%; OR, 1.33; 95% CI, 1.13-1.57).

CONCLUSION

The high proportion of successfully treated patients in the compared groups of antibiotics and the development of more adverse effects associated with fluoroquinolone use suggest that these antibiotics do not have substantial advantages compared with beta-lactams for empirical treatment of patients with SSTIs.

In vitro antimicrobial activity of liposomal meropenem against Pseudomonas aeruginosa strains

Twelve lipid formulations of liposomal meropenem were tested on six drug-susceptible and two drug-resistant Pseudomonas aeruginosa strains to determine their antibacterial activity. Cationic liposomes, especially PC/DOPE/SA 4:4:2 and PC/DOTAP/Chol 5:2:3, were more effective than anionic ones against sensitive isolates as the MICs of those formulations were two to four times lower than those of the free drug. None of the studied liposomal forms of meropenem exhibited bactericidal activity against isolates, which are drug-resistant due to low permeability. Even Fluidosomes (liposomes made of DPPC/DMPG 18:1), which demonstrated fusion with P. aeruginosa membranes, showed 4-16 times higher MICs for sensitive and resistant strains than did the free meropenem.

In vitro activities of 11 fluoroquinolones against 816 non-typhoidal strains of Salmonella enterica isolated from Finnish patients with special reference to reduced ciprofloxacin susceptibility

Background

The number of Salmonella strains with reduced susceptibility to fluoroquinolones has increased during recent years in many countries, threatening the value of this antimicrobial group in the treatment of severe salmonella infections.

Methods

We analyzed the in vitro activities of ciprofloxacin and 10 additional fluoroquinolones against 816 Salmonella strains collected from Finnish patients between 1995 and 2003. Special attention was focused on the efficacy of newer fluoroquinolones against the Salmonella strains with reduced ciprofloxacin susceptibility.

Results

The isolates represented 119 different serotypes. Of all 816 Salmonella strains, 3 (0.4%) were resistant to ciprofloxacin (MIC ≥ 4 μg/ml), 232 (28.4%) showed reduced susceptibility to ciprofloxacin (MIC ≥ 0.125 – 2 μg/ml), and 581 (71.2%) were ciprofloxacin-susceptible. The MIC₅₀ and MIC₉₀ values of ciprofloxacin for these strains were 0.032 and 0.25 μg/ml, respectively, being lower than those of the other fluoroquinolone compounds presently on market in Finland (ofloxacin, norfloxacin, levofloxacin, and moxifloxacin). For two newer quinolones, clinafloxacin and sitafloxacin, the MIC₅₀ and MIC₉₀ values were lowest, both 0.016 and 0.064 μg/ml, respectively. Moreover, clinafloxacin and sitafloxacin exhibited the lowest MIC₅₀ and MIC₉₀ values, 0.064 and 0.125 μg/ml, against the 235 Salmonella strains with reduced susceptibility and strains fully resistant to ciprofloxacin.

Conclusion

Among the registered fluoroquinolones in Finland, ciprofloxacin still appears to be the most effective drug for the treatment salmonella infections. Among the newer preparations, both clinafloxacin and sitafloxacin are promising based on in vitro studies, especially for strains showing reduced ciprofloxacin susceptibility. Their efficacy, however, has not been demonstrated in clinical investigations.

Flucloxacillin alone or combined with benzylpenicillin to treat lower limb cellulitis: a randomised controlled trial

OBJECTIVE

To determine whether using intravenous benzylpenicillin in addition to intravenous flucloxacillin would result in a more rapid clinical response in patients with lower limb cellulitis.

METHODS

This was a randomised controlled trial set in an inner city teaching hospital, comprising 81 patients with lower limb cellulitis requiring intravenous antibiotics. The main outcome measure was the mean number of doses of antibiotic required until clinical response.

RESULTS

The mean number of doses required was 8.47 (95% confidence interval (CI) 7.09 to 9.86) in the benzylpenicillin and flucloxacillin combined group. In the flucloxacillin only group it was 8.71 doses (95% CI 6.90 to 10.5), a mean difference of -0.24 doses (95% CI -2.48 to 2.01, p = 0.83). Other markers of treatment efficacy showed no difference between groups at review the following day; temperature decrease (mean difference -0.07 degrees C, 95% CI -0.76 to 0.62, p = 0.84), or diameter decrease of affected area (mean difference -34 mm, 95% CI -99 to 31, p = 0.30). Patient subjective assessments were also similar between the different drug regimen; improvement on a visual analogue scale of pain/discomfort from admission to first review (mean difference 10 mm, 95% CI -12.6 to 14.2, p = 0.91) and on second review (mean difference 15 mm, 95% CI -18.6 to 21.6, p = 0.88). Patient overall subjective feelings of improvement on first review (p = 0.32) and on second review (p = 0.64) were also similar.

CONCLUSIONS

This study provides no evidence to support the addition of intravenous benzylpenicillin to intravenous flucloxacillin in the treatment of lower limb cellulitis.

Neutropenia secundaria a betalactámicos. Una vieja compañera olvidada

Beta-lactam-induced neutropenia has been a well-recognized problem since the initiation of penicillin use. It generally develops following high-dose beta-lactam treatment lasting longer than 10 days, and its frequency rises with increases in the cumulative antibiotic dose. Beta-lactam-induced neutropenia is frequently preceded by fever or rash, which can be considered alarm signs. Unlike neutropenia induced by other nonchemotherapy drugs, beta-lactam-induced neutropenia usually lasts less than 10 days and infrequently causes infectious complications or death. Although any beta-lactam agent can cause neutropenia, recent studies have focused on cases of piperacillin-tazobactam- or cefepime-induced neutropenia; a high incidence of neutropenia has been demonstrated during prolonged treatment with these antibiotics. The apparent contradiction with the results of clinical trials that did not detect this complication is due to the fact that they involved treatments shorter than two weeks. The potential for the development of neutropenia during lengthy intravenous treatment should be borne in mind in the development of new beta-lactams.

An open-label, randomized study comparing efficacy and safety of intravenous piperacillin/tazobactam and ampicillin/sulbactam for infected diabetic foot ulcers

BACKGROUND

Soft tissue and bone infections of the lower limb continue to be a frequent and serious complication in patients with diabetes mellitus. The best choice of antimicrobial for the empiric treatment of moderate to severe diabetic foot infections has not been established clearly.

METHODS

We conducted a prospective, randomized, open-label, multicenter trial comparing piperacillin/tazobactam (P/T) (4 g/0.5 g q8h) and ampicillin/sulbactam (A/S) (2 g/1 g q6h) as a parenteral treatment for 314 adult patients with moderate-to-severe infected diabetic foot ulcers. Patients with polymicrobial infections involving methicillin-resistant Staphylococcus aureus also received vancomycin 1 g q12h.

RESULTS

Clinical efficacy rates (cure or improvement) were statistically equivalent overall (81% for P/T vs. 83.1% for A/S), and median duration of treatment was similar in the clinically evaluable populations (nine days for P/T, 10 days for A/S). Drug-related adverse events for both study drugs were comparable in frequency and type.

CONCLUSIONS

Although both study drugs provide safe and effective empiric treatment for moderate-to-severe infected diabetic foot ulcers, piperacillin/tazobactam has the advantage of covering Pseudomonas aeruginosa (bacteriologic success rate of 85.7%), the most commonly isolated gram-negative pathogen in this study.

A systematic approach to diabetic foot infections

Foot infection is the most common reason for hospitalization and subsequent lower extremity amputation among persons with diabetes. Foot ulceration caused by diabetic neuropathy, trauma, and peripheral vascular disease can lead to a limbor life-threatening infection. The optimum treatment of these potentially devastating conditions depends on a multidisciplinary approach that addresses the related or underlying disorders and thus ensures proper wound healing and a positive outcome. In addition to antibiotic therapy, severe soft-tissue or bone infections may necessitate surgical treatment, including drainage, débridement, and vascular reconstruction. Initial (empiric) antibiotic therapy should provide coverage against staphylococci and streptococci and should be revised according culture results. Antibiotic therapy is not indicated in clinically noninfected wounds. The duration of antibiotic treatment can range from 1 week for mild infections to 6 weeks or more for residual osteomyelitis and severe deep tissue infections. Aggressive (and sometimes repeated or staged) surgical intervention and appropriate antibiotic therapy can reduce the likelihood of a major amputation and the duration of hospitalization.

A review of the microbiology, antibiotic usage and resistance in chronic skin wounds

Chronic leg and foot wounds represent an increasing burden to healthcare systems as the age of the population increases. The deep dermal tissues of all chronic wounds harbour microorganisms, however, the precise interaction between microbes in the wounds and impaired healing is unknown. With regard to antibiotic therapy, there is a lack of evidence concerning its effectiveness, optimal regimens or clinical indications for treatment. Despite this lack of evidence, antibiotics are frequently a feature of the management of chronic wounds and these patients receive significantly more antibiotic prescriptions (both systemic and topical) than age and sex-matched patients. Current guidelines for antibiotic prescribing for such wounds are often based on expert opinion rather than scientific fact and may present difficulties in interpretation and implementation to the clinician. Although the increasing prevalence of antibiotic resistance is widely recognized, the relationships between antibiotic resistance, chronic wound microbiology and rationales for antibiotic therapy have yet to be determined. This review discusses the role of microbes in chronic wounds from a clinical perspective with particular focus on the occurrence of bacteria and their impact on such wounds. The evidence and role of antibiotics in the treatment of such wounds are outlined and current practice of antibiotic usage for chronic wounds in the primary care setting described. The implications of antibiotic usage with regard to antibiotic resistance are also considered.

Results of a multicenter, randomized, open-label efficacy and safety study of two doses of tigecycline for complicated skin and skin-structure infections in hospitalized patients

BACKGROUND

Tigecycline is a broad-spectrum glycylcycline antibiotic being investigated for the treatment of serious infections in hospitalized patients. Tigecycline has been shown to be efficacious against serious infections in animals, and preliminary studies in healthy adults have shown that tigecycline has an acceptable tolerability profile.

OBJECTIVE

This study compared the clinical and microbiological efficacy, pharmacokinetic properties, and tolerability of 2 doses of tigecycline in hospitalized patients with a complicated skin and skin-structure infection (cSSSI).

METHODS

This Phase II, randomized, open-label study was conducted between September 1999 and March 2001 at 14 investigative centers across the United States. Patients were randomized to receive tigecycline 25 or 50 mg IV q12h for 7 to 14 days. The primary efficacy end point was the clinically observed cure rate among clinically evaluable (CE) patients at the test-of-cure visit. Secondary end points were the clinical cure rate at the end of treatment and bacteriologic response in microbiologically evaluable (ME) patients. Also, in vitro tests of susceptibility to tigecycline were performed for selected pathogens known to cause skin infections, including methicillin-resistant and methicillin-susceptible Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Enterococcus faecium. Tolerability assessments also were conducted.

RESULTS

A total of 160 patients received > or =1 dose of tigecycline; 109 patients were CE, and 91 were ME. The majority of patients (74%) were men, and the mean (SD) age was 49.0 (14.8) years. At the test-of-cure visit, the clinical cure rate in the 25-mg group was 67% (95% CI, 53.3%-79.3%) and in the 50-mg group was 74% (95% CI, 60.3%-85.0%). In the 25-mg group, 56% of the patients had eradication (95% CI, 40.0%-70.4%) of the pathogens compared with 69% (95% CI, 54.2%-82.3%) in the 50-mg group. Values for the minimum concentration of tigecycline that is inhibitory for 90% of all isolates ranged from 0.06 to 0.50 microg/mL for the selected pathogens. Both tigecycline doses were generally well tolerated. Nausea and vomiting were the most common adverse events.

CONCLUSIONS

In this study, tigecycline appeared efficacious and showed a favorable pharmacokinetic profile and an acceptable safety profile in the treatment of hospitalized patients with cSSSI. In patients who received 50-mg doses of tigecycline q12h, the clinical cure rates and microbial eradication rates were 74% and 70%, respectively, and were 67% and 56% in patients who received 25-mg doses.

Advances in the treatment of diabetic foot infections

Lower extremity infections are frequent causes of substantial morbidity and mortality in the diabetic population, and these infections consume a large portion of resources expended on diabetic complications. Gram-positive cocci, particularly Staphylococcus aureus, are the most important pathogens in diabetic foot infections. These organisms are predominant both in mild infections (which are often monomicrobial), as well as in more severe and chronic infected wounds that more often have a polymicrobial cause. Appropriate clinical assessment and culturing of infections are critical in establishing the presence and severity of infection, in detecting osteomyelitis, and in directing the optimal treatment approach. Following necessary debridement and other surgical interventions (e.g., bone resection, revascularization), appropriate antibiotic therapy is a cornerstone of managing the infected lower extremity. Peripheral vascular (i.e., arterial) insufficiency and the increasing prevalence of antibiotic resistance are primary barriers to successfully managing these infections. Fortunately, alternative delivery systems (e.g., antibiotic beads, impregnated sponges) and novel antibiotics (e.g., levofloxacin, linezolid) are providing possible solutions to the challenges posed by this physically, emotionally, and financially devastating condition.

Efficacy of ertapenem against methicillin-susceptible Staphylococcus aureus in complicated skin/skin structure infections: results of a double-blind clinical trial versus piperacillin-tazobactam

Staphylococcus aureus is the predominant pathogen in complicated skin/skin structure infections. In this analysis of a subgroup of data from a randomised, double-blind trial, the efficacy of ertapenem 1 g daily was compared with piperacillin-tazobactam 3.375 g Q6H for treatment of complicated skin/skin structure infections caused by methicillin-susceptible S. aureus (MSSA). Of the 529 treated patients in this trial, 185 (35.0%) had MSSA as a baseline pathogen. At the test of cure assessment 10-21 days post-therapy, 54 of 67 (80.6%) protocol evaluable patients in the ertapenem group and 55 of 68 (80.9%) in the piperacillin-tazobactam group were cured (odds ratio: 1.0 (95% confidence interval (CI): 0.4-2.4), P = 0.99). In both treatment groups, cure rates were higher in patients with monomicrobial than polymicrobial infections, but the difference was not significant. In this subgroup analysis of patients with MSSA complicated skin/skin structure infections, therapy with ertapenem 1 g daily was as effective as piperacillin-tazobactam 13.5 g divided in four daily doses.

Incidence of Neutropenia during Treatment of Bone-Related Infections with Piperacillin-Tazobactam

Of 41 patients with bone-related infections who were treated for > or =10 days with piperacillin-tazobactam, 14 (34%) developed neutropenia. Cumulative doses of piperacillin administered to neutropenic patients were higher than those administered to nonneutropenic ones (330 vs. 237 g; P=.008), and an inverse correlation was detected between the absolute neutrophil count at the end of treatment and the cumulative dose of piperacillin (r=-0.47, P=.002). Moreover, the incidence of piperacillin-tazobactam-induced neutropenia increased with an increase in the cumulative dose of piperacillin: 0% of patients in the first quartile of cumulative piperacillin doses, 33.3% in the second quartile, 40% in the third quartile, and 66.7% in the fourth quartile.

A practical guide to the treatment of complicated skin and soft tissue infections

Complicated skin and soft tissue infections (SSTIs) remain a common reason for hospitalisation. Optimal management of complicated SSTIs begins with a physical examination, and obtaining the complete social and medical history of the patient. Empirical intravenous antibacterial therapy is guided by expected pathogens, patient factors and diagnostic procedure reports, such as the Gram-stained smear of discharge or exudates. The majority of community-acquired SSTIs are caused by Staphylococcus aureus and beta-haemolytic streptococci. On the basis of recent surveillance data, 80-90% of these pathogens remain susceptible to cefazolin or oxacillin. Consequently, a first generation cephalosporin or an antistaphylococcal penicillin remains the first line empirical therapy for community-acquired skin and soft tissue infections. Vancomycin may be an appropriate alternative when vancomycin-resistant S. aureus is highly suspected on the basis of patient history and co-morbid conditions. With the global emergence and spread of macrolide-resistant S. aureus and beta-haemolytic streptococci, clindamycin rather than a macrolide is the recommended agent for empirical antibacterial therapy of community-acquired SSTIs in penicillin-allergic patients. Nosocomial complicated SSTIs are predominantly caused by S. aureus, Pseudomonas aeruginosa, Enterococcus spp., Escherichia coli and other Enterobacteriaceae. Piperacillin/tazobactam with or without vancomycin is the preferred agent for empirical treatment depending on local resistance statistics. The newer fluoroquinolones may have a role in the treatment of complicated SSTIs, especially in penicillin-allergic patients. More clinical studies are needed before a formal recommendation can be made. Many of the newer antimicrobial agents such as the carbapenems, oxazolidinones and streptogramins have been shown to be effective for the treatment of complicated SSTIs. However, because of their proven activity against highly resistant organisms including methicillin-resistant S. aureus and vancomycin-resistant enterococci (oxazolidinones and streptogramins), and Gram-negative bacilli producing extended spectrum beta-lactamases (carbapenems), these antibacterials should be reserved for life-threatening situations and/or when resistant pathogens are suspected. Complicated skin and soft tissue infections are often associated with exudates, ulcerations, fluid collections or abscesses. Adequate debridement of devitalized tissues and drainage of abscesses and fluid collections in addition to systemic antibacterial therapy is an integral part of appropriate management.

Diabetic foot infections and antibiotic therapy

Diabetic foot infections are associated with high morbidity and mortality rates as well as significant financial impact on the health care system. Improved patient outcomes and intelligent use of resources should determine the selection of diagnostic procedures and the therapeutic modalities used. Diabetic patients who develop lower extremity infections require a multidisciplinary approach in the management of their infections and other disorders. Aggressive surgical debridement and appropriate and adequate antibiotic therapy are necessary to successfully treat severe foot infections and permit faster recovery.

Ertapenem versus piperacillin-tazobactam for treatment of mixed anaerobic complicated intra-abdominal, complicated skin and skin structure, and acute pelvic infections

BACKGROUND

Anaerobes are an important component of many serious, deep tissue infections, especially complicated intra-abdominal (IAI), complicated skin and skin structure (SSSI), and acute pelvic (PI) infections. This study compares the efficacy of ertapenem, 1 g once a day, in the treatment of adults with anaerobic IAI, SSSI, and PI to piperacillin-tazobactam, 3.375 g every 6 hours.

METHODS

Three randomized, double-blind trials comparing ertapenem to piperacillin-tazobactam for treatment of IAI, SSSI, and PI were conducted. This subgroup analysis included 623 patients, whose baseline culture grew one or more anaerobic pathogens, from these three studies.

RESULTS

Anaerobes most commonly isolated were Bacteroides fragilis group (IAI) and peptostreptococci (SSSI and PI). The median duration of ertapenem and piperacillin-tazobactam therapy, respectively, in these subgroups was 6 and 7 days for IAI, 7 and 8 days for SSSI, and 4 and 5 days for PI. Cure rates for all evaluable patients with anaerobic infection were 89.3% (242/271) for ertapenem and 85.9% (220/256) for piperacillin-tazobactam (95% CI for the difference, adjusting for infection, -2.6% to 9.3%), indicating that the two treatments were equivalent. Cure rates by infection, for ertapenem and piperacillin-tazobactam, respectively, were as follows: IAI, 86.4% (133/154) and 82.4% (117/142); SSSI, 84.4% (27/32) and 82.4% (28/34); PI, 96.5% (82/85) and 93.8% (75/80). The frequency and severity of drug-related adverse experiences were comparable in both treatment groups.

CONCLUSION

In this subgroup analysis, ertapenem was as effective as piperacillin-tazobactam for treatment of adults with moderate to severe anaerobic IAI, SSSI, and PI, was generally well tolerated, and had a similar safety profile.

Surgical infections with enterococcus: outcome in patients treated with ertapenem versus piperacillin-tazobactam

BACKGROUND

The pathogenicity of Enterococcus in polymicrobial surgical infections is controversial. The objective of this analysis was two-fold. The impact of Enterococcus on clinical outcome was assessed in adults with complicated intra-abdominal (IAI), complicated skin and skin structure (CSSSI), or acute pelvic (PI) infection treated with ertapenem or piperacillin-tazobactam, which is more active in vitro against enterococci than ertapenem. Baseline characteristics were identified that were associated with Enterococcus infection and with treatment failure.

METHODS

This analysis included 1,558 patients treated in three randomized, triple-blind studies. Of these patients, 223 had Enterococcus in initial cultures: 125 of 623 (20%) with IAI, 28 of 529 (5%) with CSSSI, and 70 of 406 (17%) with PI. Logistic regression models were fit to assess each objective.

RESULTS

The cure rates for the two treatment groups were similar in each of the three studies, regardless of the presence or absence of Enterococcus. Cure rates for both treatment groups combined were significantly lower in patients with Enterococcus than without Enterococcus for IAI (76% [69/91] versus 87% [264/305], OR 2.3 [95% CI, 1.2-4.1], P = 0.009) and CSSSI (58% [11/19] versus 84% [241/287], OR 3.8 [95% CI, 1.5-10.0], P = 0.010); but for PI, rates were similar (96% [50/52] versus 92% [188/205], OR 0.4 [95% CI, 0.1-1.9], P = 0.220). Characteristics predictive of the presence of Enterococcus were Pseudomonas aeruginosa as a baseline pathogen for IAI, older age, and the presence of a complicating underlying disease for CSSSI, and infection severity rated moderate rather than severe for PI. The strongest predictors of treatment failure were >2 days postoperative infection at study entry for patients with IAI and older age for patients with CSSSI.

CONCLUSION

Choice of antimicrobial therapy did not affect cure rates in patients with or without Enterococcus. The strongest predictors of failure were postoperative infection at study entry in patients with IAI and older age in patients with CSSSI.

In vitro activity of ertapenem against common clinical isolates in relation to human pharmacokinetics

The in vitro activity of ertapenem against bacterial pathogens isolated from patients with moderate to severe complicated intra-abdominal, complicated skin/skin structure, acute pelvic, or complicated urinary tract infection or community acquired pneumonia was compared to ceftriaxone and piperacillin-tazobactam and related to known plasma concentrations of the three agents. Ertapenem was more potent against methicillin-susceptible Staphylococcus aureus (MSSA) than ceftriaxone and piperacillin-tazobactam and was more potent and more active than both of these agents against Enterobacteriaceae and anaerobes. Piperacillin-tazobactam was the most active agent against enterococci and Pseudomonas aeruginosa. All isolates of Enterobacteriaceae (n=1088), Streptococcus pyogenes (n=37), Streptococcus agalactiae (n=48), MSSA (n=187), Haemophilus influenzae (n=59), and Moraxella catarrhalis (n=9) were susceptible to ertapenem; < 1% of 1284 anaerobes and only 1 of 113 Streptococcus pneumoniae (a penicillin-resistant isolate) were resistant to ertapenem. The MIC value at which 90% of all Enterobacteriaceae, streptococci, MSSA, H. influenzae, M. catarrhalis, and anaerobes were inhibited (MIC90) was < or = 1 microg/ml and below the mean plasma concentration of total ertapenem following a 1 g intravenous infusion for at least 24 hours, i.e., the entire recommended dosing interval, and below the free drug concentration for at least 8 h.

General microbiology and in vitro susceptibility of anaerobes isolated from complicated skin and skin-structure infections in patients enrolled in a comparative trial of ertapenem versus piperacillin-tazobactam

In a recently completed study of once-a-day ertapenem versus piperacillin-tazobactam every 6 h in the treatment of complicated skin and skin-structure infections, 540 patients were randomized in a 1rcolon;1 ratio and assigned to 1 of 2 strata: those with a complicating underlying disease or all others. The most common infections in the study were deep soft-tissue abscess (18.9%), followed by diabetic lower extremity infection (18.1%); 7.0% of these were perineal cellulitis/abscess. With the exception of methicillin-resistant Staphylococcus aureus, almost all of the predominant aerobic pathogens were susceptible to both study drugs. Eighty-seven patients (16%) had >/=1 anaerobe identified in their baseline wound cultures, with a total of 232 anaerobic isolates. Of the 141 anaerobes tested for susceptibility, 97.2% were susceptible to ertapenem and 97.9% to piperacillin-tazobactam. Ertapenem had excellent in vitro activity against the most common aerobic pathogens and almost all anaerobes recovered from patients with infections of the skin and skin structures.

Ertapenem once daily versus piperacillin-tazobactam 4 times per day for treatment of complicated skin and skin-structure infections in adults: results of a prospective, randomized, double-blind multicenter study

We conducted a prospective, randomized, double-blind trial comparing ertapenem (1 g once daily) with piperacillin-tazobactam (3.375 g every 6 h) as parenteral treatment for 540 adults with complicated skin and skin-structure infections. The most common diagnoses were skin or soft-tissue abscesses and lower-extremity infections associated with diabetes. The mean duration (+/- standard deviation) of therapy was 9.1+/-3.1 days for ertapenem and 9.8+/-3.3 days for piperacillin-tazobactam. At the assessment of primary efficacy end point, 10-21 days after treatment, 82.4% of those who received ertapenem and 84.4% of those who received piperacillin-tazobactam were cured. The difference in response rates, adjusting for the patients' assigned strata, was -2.0% (95% confidence interval, -10.2% to 6.2%), indicating that the response rates in the 2 treatment groups were equivalent. Cure rates for the 2 treatment groups were similar when compared by stratum, diagnosis, and severity of infection. The frequency and severity of drug-related adverse events were similar in the treatment groups.