Mupirocin resistance after long-term use for Staphylococcus aureus colonization in patients undergoing chronic peritoneal dialysis

Randomized, Controlled Trial of Topical Exit-Site Application of Honey (Medihoney)versusMupirocin for the Prevention of Catheter-Associated Infections in Hemodialysis Patients

The clinical usefulness of hemodialysis catheters is limited by increased infectious morbidity and mortality. Topical antiseptic agents, such as mupirocin, are effective at reducing this risk but have been reported to select for antibiotic-resistant strains. The aim of the present study was to determine the efficacy and the safety of exit-site application of a standardized antibacterial honey versus mupirocin in preventing catheter-associated infections. A randomized, controlled trial was performed comparing the effect of thrice-weekly exit-site application of Medihoney versus mupirocin on infection rates in patients who were receiving hemodialysis via tunneled, cuffed central venous catheters. A total of 101 patients were enrolled. The incidences of catheter-associated bacteremias in honey-treated (n = 51) and mupirocin-treated (n = 50) patients were comparable (0.97 versus 0.85 episodes per 1000 catheter-days, respectively; NS). On Cox proportional hazards model analysis, the use of honey was not significantly associated with bacteremia-free survival (unadjusted hazard ratio, 0.94; 95% confidence interval, 0.27 to 3.24; P = 0.92). No exit-site infections occurred. During the study period, 2% of staphylococcal isolates within the hospital were mupirocin resistant. Thrice-weekly application of standardized antibacterial honey to hemodialysis catheter exit sites was safe, cheap, and effective and resulted in a comparable rate of catheter-associated infection to that obtained with mupirocin (although the study was not adequately powered to assess therapeutic equivalence). The effectiveness of honey against antibiotic-resistant microorganisms and its low likelihood of selecting for further resistant strains suggest that this agent may represent a satisfactory alternative means of chemoprophylaxis in patients with central venous catheters.

Randomized, double-blind trial of antibiotic exit site cream for prevention of exit site infection in peritoneal dialysis patients

Infection is the Achilles heel of peritoneal dialysis. Exit site mupirocin prevents Staphylococcus aureus peritoneal dialysis (PD) infections but does not reduce Pseudomonas aeruginosa or other Gram-negative infections, which are associated with considerable morbidity and sometimes death. Patients from three centers (53% incident to PD and 47% prevalent) were randomized in a double-blinded manner to daily mupirocin or gentamicin cream to the catheter exit site. Infections were tracked prospectively by organism and expressed as episodes per dialysis-year at risk. A total of 133 patients were randomized, 67 to gentamicin and 66 to mupirocin cream. Catheter infection rates were 0.23/yr with gentamicin cream versus 0.54/yr with mupirocin (P = 0.005). Time to first catheter infection was longer using gentamicin (P = 0.03). There were no P. aeruginosa catheter infections using gentamicin compared with 0.11/yr using mupirocin (P < 0.003). S. aureus exit site infections were infrequent in both groups (0.06 and 0.08/yr; P = 0.44). Peritonitis rates were 0.34/yr versus 0.52/yr (P = 0.03), with a striking decrease in Gram-negative peritonitis (0.02/yr versus 0.15/yr; P = 0.003) using gentamicin compared with mupirocin cream, respectively. Gentamicin use was a significant predictor of lower peritonitis rates (relative risk, 0.52; 95% confidence interval, 0.29 to 0.93; P < 0.03), controlling for center and incident versus prevalent patients. Gentamicin cream applied daily to the peritoneal catheter exit site reduced P. aeruginosa and other Gram-negative catheter infections and reduced peritonitis by 35%, particularly Gram-negative organisms. Gentamicin cream was as effective as mupirocin in preventing S. aureus infections. Daily gentamicin cream at the exit site should be the prophylaxis of choice for PD patients.

Catheter-related infections in children treated with hemodialysis

Infectious complications of the central venous catheter (CVC) are a major source of morbidity among children treated with hemodialysis (HD), with catheter-related bloodstream infections (CRBSI) being the most important clinical manifestations. As only a few studies of children on HD have been published, the management of CVC-related infections in this population is mainly based on data derived from adults or occasionally from children not affected by end-stage renal disease (ESRD). The aim of this review is to discuss current knowledge concerning the epidemiology, prevention, and treatment of catheter-related infections in children on HD. Catheters impregnated with antibiotics/antiseptics, lock antibiotic prophylaxis, nasal mupirocin, and the application of ointments at the exit-site have all been proposed as means of reducing the risk of CVC infections, but their real efficacy in the pediatric population has not yet been demonstrated. Furthermore, it is not clear how long antibiotic therapy should be continued, and there is still debate as to whether the catheter has to be removed. We propose some practical guidelines for the management of CRBSI in children with percutaneously inserted and surgically implanted HD catheters, but a number of unresolved clinical issues still remain, which will require prospective clinical trials specifically performed in pediatric patients with ESRD.

Dynamic Analysis of Peritoneal Dialysis Associated Peritonitis

Peritoneal dialysis associated peritonitis (PDAP) has a historical incidence of approximately 0.3 to 0.5 episodes per patient per year; it represents the leading cause for hospitalization in patients on peritoneal dialysis (PD) and imposes a significant burden of morbidity. PDAP is unique in that each dialysis exchange removes a relatively large fraction of the bacteria laden free intraperitoneal fluid. The attendant removal of bacteria existing in the fluid phase (planktonic bacteria) may interact with bacterial growth to modulate the rate at which the peritoneal burden of microorganisms is reduced. We investigated the potential interactions between bacterial growth dynamics, multiphase bacterial kinetics, and mechanical clearance of microorganisms using simple mathematical analyses based upon in vitro data regarding bacterial growth kinetics in peritoneal dialysate. There are strong dynamic interactions predicted between fluid phase bacterial kinetics, dialysis prescription, and the mechanical clearance of planktonic peritoneal bacteria. There are also strong interactions between fluid phase bacterial kinetics and the kinetics of biofilm/sanctuary site formation and clearance. More frequent exchanges might significantly hasten the clearance of intraperitoneal planktonic bacteria in the absence of catheter-associated bacterial biofilm. The formation of bacteria laden biofilm raises the possibility of a "commensal state," in which ongoing mechanical clearance limits the total peritoneal bacterial burden.

Staphylococcus aureus colonization and nosocomial infections: Implications for prevention

Colonization with Staphylococcus aureus is a risk factor for invasive S. aureus infections. Intranasal mupirocin has effectively eradicated S. aureus colonization and appears to prevent S. aureus nosocomial infections in some patient populations. In hospitals and communities where mupirocin use has been widespread, resistance to the drug has emerged. New strategies and agents are needed if we want to significantly decrease the risk of S. aureus infections.

Routine use of mupirocin at the peritoneal catheter exit site and mupirocin resistance: still low after 7 years

OBJECTIVE

The purpose of this study (the third in a series of similar studies) is to evaluate the prevalence of Staphylococcus aureus (SA), methicillin-resistant SA (MRSA) and mupirocin-resistant SA (MuRSA) carriers in a peritoneal dialysis centre where patients have been instructed to use prophylactic mupirocin ointment at the catheter exit site over the last 7 years.

METHODS

Swabs were taken from catheter exit site, nares, axillae and groin in 147 chronic peritoneal dialysis out-patients between November 2003 and January 2004. Axillae/groin and nasal samples were pooled and cultured in the same medium, whereas exit site swabs were cultured separately. All SA isolated were tested for methicillin and mupirocin resistance using oxacillin screening plates and E-test strips.

RESULTS

Sixteen of 147 patients (10.9%) were found to be SA carriers: of these 13 (8.8%) had a positive nasal/axillae/groin culture; two (1.4%) had both nasal/axillae/groin- and exit site-positive culture; and one (0.7%) had only exit site-positive culture. In these 16 SA carriers, we found mupirocin-resistant strains (MuRSA) in four patients (25%) and MRSA in two patients (12.5%). Among the four MuRSA carriers, one had both nasal/axillae/groin- and exit site-positive culture and three had only nasal/axillae/groin-positive culture. Three high-level resistance and one low-level resistance MuRSA carriers were isolated. One MuRSA strain was also methicillin resistant. All MRSA strains were sensitive to vancomycin and rifampicin.

CONCLUSION

After 7 years' routine use of prophylactic mupirocin ointment at the catheter exit site in non-selected chronic peritoneal dialysis patients, MuRSA was found in 25% of SA strains isolated or in 2.7% of the patients. Compared with our previous study, 3 years earlier, there is no significant increase in the MuRSA prevalence in peritoneal dialysis patients who routinely apply mupirocin ointment at the catheter exit site.

Control of endemic MRSA-what is the evidence? A personal view

Although there is extensive literature on the control of MRSA, when that concerning epidemics is excluded, only a limited amount remains regarding the control of endemic MRSA. Several guidelines have been recently published recommending stringent control measures, which are often suggested based on their success in controlling MRSA outbreaks in hospitals with few MRSA or in containing MRSA cases introduced into a hospital with no MRSA. In these settings, multiple measures are usually introduced with apparently successful results. However, results may not be generalizable to other settings and we do not know the minimum effective measures required for MRSA containment. This paper aims critically to review the literature to determine whether evidence exists for the value of the infection control measures that are widely recommended in the endemic setting. Much of this literature is based on observational studies, with few randomized, controlled trials having been conducted. More well-designed studies are required before many of the principles on which we build infection control programmes can be regarded as evidence based.

Continuous peritoneal dialysis-associated peritonitis: a review and current concepts

The percentage of end-stage renal disease (ESRD) patients in the United States maintained on continuous peritoneal dialysis (CPD) therapy is decreasing. Complications from CPD therapy, including peritonitis, may be the reason for the decline. Improvements in CPD technology and a better understanding of the risk factors that predispose patients to the development of peritonitis have been responsible for a decline in the rate of peritonitis. Yet peritonitis remains a significant cause of patient morbidity and mortality and the overall outcome of peritonitis is not acceptable. Factors that have limited our ability to lessen the impact of peritonitis include a lack of data on dosing antibiotics in patients on continuous cycling peritoneal dialysis (CCPD) therapy, a lack of knowledge concerning the biology of bacterial biofilm, and the development of resistance to the current prophylactic antibiotic protocols. Further studies are needed concerning the optimal management of the peritoneal catheter and whether it is feasible to resume CPD therapy after catheter removal.

Peritoneal catheter exit-site infections: predisposing factors, prevention and treatment

Catheter-related infections, exit-site-tunnel infections and peritonitis remain the Achilles heel of peritoneal dialysis. Although the overall incidence of peritoneal-dialysis-related infectious complications has been reduced since the introduction of the Y-set and double bag system, approximately one-fifth of peritonitis episodes are associated with catheter exit-site and tunnel infections. Since its development in 1968, the Tenckhoff catheter has become one of the most widely used peritoneal catheters, and many have proposed that a number of modifications have made it a better choice. Controversies concerning the effect on exit-site infections of catheter(s) with one or two cuffs, with straight, coiled, Swan-Neck, or other modifications led to the randomized controlled studies that are reviewed in this paper. Several studies have confirmed that mupirocin, applied at the exit-site as part of regular exit-site care, reduces the risk of S. aureus exit-site and tunnel infections. Recently, the emergence on a world-wide basis of mupirocin-resistant S. aureus (MuRSA) in peritoneal dialysis patients has brought this prophylactic strategy into question. However the low frequency of resistant organisms after four years of mupirocin prophylaxis suggests that we can continue its use with annual surveillance. Once established, exit-site infections may respond to appropriate treatment, but if not the only option may be catheter removal and replacement. Although peritonitis risk has decreased over the past decade, mainly due to improvements in connection technology, exit-site and tunnel infections have not. An exit-site infection that does not respond to treatment may lead to tunnel infection and to persistent peritonitis, which may require catheter removal and occasionally discontinuation of the peritoneal dialysis. Therefore it is important to be familiar with these factors that predispose to exit-site infection and to know how to prevent and to treat such infections. This review will discuss factors that predispose to catheter-related exit-site infections, techniques of exit-site care, and ways to prevent exit-site infection, with emphasis on S. aureus infections and their treatment.

New insights on preventing and managing peritonitis

Methods to prevent peritonitis are an essential component of any successful peritoneal dialysis (PD) program. Careful attention to training of the parents and child on the proper technique of PD and avoidance of manual spiking by using an assist device for the cycler, or use of the double-bag system for continuous ambulatory PD, should decrease risk of peritonitis from touch contamination. Secondly, reduction of peritonitis can be achieved through reduction of exit site infections by use of mupirocin antibiotic cream at the exit site of the PD catheter as part of routine care. If an exit site infection develops and is refractory to therapy, then the PD catheter can be successfully replaced as a single procedure, to reduce the risk of peritonitis. The third step in reducing the risk of peritonitis is to avoid repetitive episodes with the same organism. This may again involve replacing the catheter; as long as the effluent can be cleared, this again can be performed as a single procedure, thus allowing the child to avoid the trauma of hemodialysis. The focus in pediatric PD programs must always be on preserving the peritoneal membrane, and not on preservation of the catheter. With careful attention, peritonitis can become an uncommon event.

Mupirocin prophylaxis to prevent Staphylococcus aureus infection in patients undergoing dialysis: a meta-analysis

A systematic review of the English-language literature was performed to determine the overall benefit of mupirocin therapy in reducing the rate of Staphylococcus aureus infection among patients undergoing hemodialysis (HD) or peritoneal dialysis (PD). Included studies met the following criteria: they were randomized clinical trials or cohort studies; cohorts consisted of adults (age, > or =18 years) requiring HD or PD; mupirocin therapy was administered to the treatment group, and placebo or no therapy was administered to the control group; and the primary outcome of interest was the difference in the number of S. aureus infections among mupirocin-treated and -untreated patients. Ten studies described in 9 articles were analyzed. A total of 2445 patients were included in the analysis. Use of mupirocin reduced the rate of S. aureus infections by 68% (95% confidence interval [CI], 57%-76%) among all patients undergoing dialysis; risk reductions were 80% (95% CI, 65%-89%) among patients undergoing HD and 63% (95% CI, 50%-73%) among patients undergoing PD. When data were stratified by type of infection, S. aureus bacteremia was found to be reduced by 78% among patients undergoing HD, and peritonitis and exit-site infections were found to be reduced by 66% and 62%, respectively, among patients undergoing PD. Mupirocin prophylaxis substantially reduces the rate of S. aureus infection in the dialysis population. Optimal regimens that minimize the emergence of mupirocin resistance need to be explored.

Treatment of Staphylococcus aureus colonization and prophylaxis for infection with topical intranasal mupirocin: an evidence-based review

Most Staphylococcus aureus infections are endogenously acquired, and treatment of nasal carriage is one potential strategy for prevention. We critically appraised the published evidence regarding the efficacy of intranasal mupirocin for eradication of S. aureus nasal carriage and for prophylaxis of infection. Sixteen randomized, controlled trials were appraised; 9 trials assessed eradication of colonization as a primary outcome measure, and 7 assessed the reduction in the rate of infection. Mupirocin was generally highly effective for eradication of nasal carriage in the short term. Prophylactic treatment of patients with intranasal mupirocin in large trials did not lead to a significant reduction in the overall rate of infections. However, subgroup analyses and several small studies revealed lower rates of S. aureus infection among selected populations of patients with nasal carriage treated with mupirocin. Although mupirocin is effective at reducing nasal carriage, routine use of topical intranasal mupirocin for infection prophylaxis is not supported by the currently available evidence.

Management of peritonitis in children receiving chronic peritoneal dialysis

Bacterial peritonitis is a major threat to long-term peritoneal membrane function in pediatric patients receiving chronic peritoneal dialysis (CPD). This review summarizes the demographics, risk factors, and current recommendations regarding diagnostic procedures, management, and prevention of peritonitis in children. Albeit decreasing in incidence, bacterial peritonitis remains a major cause of technique failure in children with endstage renal disease receiving CPD. The use of standardized diagnostic procedures, efficacious antibacterial treatment, and objective response criteria are crucial in improving the outcome of this complication. Current guidelines recommend combining a first- and third-generation cephalosporin for empiric therapy in uncomplicated cases. The initial use of a glycopeptide/third-generation cephalosporin combination should be restricted to patients with risk factors for severe disease, as defined by clinical presentation, young age (<2 years), and recent infection with a methicillin resistant micro-organism. Several risk factors for primary or relapsing peritonitis have been identified, some of which are amenable to preventive measures. These relate to catheter design and implantation technique, connection methodology, early catheter removal in refractory or relapsing peritonitis, and eradication of Staphylococcus aureus from the catheter exit site and/or nasal reservoirs in patients and their caregivers.

Mupirocin resistance in clinical isolates of Staphylococcus aureus

One hundred isolates of Staphylococcs aureus were collected in a laboratory serving several hospitals and clinics in southeastern Wisconsin and tested for mupirocin susceptibility. Only two isolates of S. aureus showed mupirocin resistance. The mupirocin-resistant isolates were from hospitalized patients with positive blood cultures.

Clinical effectiveness of different approaches to peritoneal dialysis catheter exit-site care

OBJECTIVE

The objective of this review was to appraise and synthesise the best available evidence on the clinical effectiveness of peritoneal dialysis catheter exit-site care.

INCLUSION CRITERIA

This review considered all randomised controlled trials that evaluated the effectiveness of peritoneal exit-site care. In the absence of randomised controlled trials, other controlled research designs such as non-randomised controlled trials were considered for inclusion in a narrative summary to enable the identification of current approaches and possible future strategies. Participants of interest were adults with chronic renal failure on maintenance peritoneal dialysis. Interventions of interest were those used to manage peritoneal catheter exit sites, and included types of dressings, frequency of dressings, types of skin care, and use of topical antiseptic or antimicrobial agents.

SEARCH STRATEGY

The search sought to find both published and unpublished studies. An initial limited search of MEDLINE and CINAHL databases was undertaken to identify key words contained in the title or abstract, and index terms used to describe relevant articles. A second extensive search was undertaken using all identified key words and index terms. The third step was a search of the reference lists and bibliographies of all relevant articles.

METHODOLOGICAL QUALITY

All identified studies that met the inclusion criteria were assessed for methodological validity by two reviewers prior to inclusion in the review. Critical appraisal of studies focused on identifying bias in selection, performance, attrition and detection.

RESULTS

This review found few studies of sufficient quality to meet the inclusion criteria. The included studies often utilised historical control groups, potentially confounding measurement of their outcomes. The outcome measures varied considerably, thus meta-analysis was not possible.

CONCLUSIONS

This review suggests topical mupirocin may reduce the risk of exit-site infection; however, the clinical effectiveness of any one antibiotic, antiseptic or dressing procedure was not established for the prevention or reduction of exit-site infection rates or peritonitis. This review has underlined large gaps in the existing knowledge on the care of exit sites in patients on peritoneal dialysis.

Infection with antimicrobial-resistant microorganisms in dialysis patients

The prevalence of antimicrobial-resistant microorganisms in various health care settings, including outpatient dialysis facilities, has increased dramatically in the last decade. Antimicrobial use and patient-to-patient transmission of resistant strains are the two main factors that have contributed to this rapid increase. Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci are commonly isolated as a cause of hemodialysis (HD) catheter-related bacteremia and peritoneal dialysis (PD)-related catheter infection and peritonitis. The widespread use of vancomycin in dialysis patients is of concern because of an increase in the prevalence of vancomycin-resistant enterococci (VRE) in dialysis patients. Staphylococci with reduced sensitivity to vancomycin have also appeared in dialysis patients. A more recent problem is the appearance of S. aureus isolates with a high degree of resistance to the topical antimicrobial agent mupirocin. This has been seen in PD patients who have received prophylactic application of mupirocin at the peritoneal catheter exit site. Appropriate antimicrobial use will help protect the efficacy of currently used antibiotics, such as vancomycin. Published guidelines for use of vancomycin should be followed. New antimicrobials such as linezolid and quinupristin/dalfopristin have activity against VRE and MRSA, but resistance to these agents has already occurred. Preventing transmission of antimicrobial-resistant microorganisms in health care settings, including outpatient dialysis facilities, is important in limiting the spread of these resistant organisms.

Preventing bacterial infections and antimicrobial resistance in dialysis patients

Antimicrobial use, in concert with patient-to-patient transmission of resistant strains, has caused a rapid increase in the prevalence of antimicrobial resistance in recent years. This increase is a particular threat to dialysis patients, who often have been in the forefront of the epidemic of resistance. In this report, which was written in collaboration between the American Society of Nephrology and the Centers for Disease Control and Prevention and has been endorsed by the Executive Council of the Infectious Diseases Society of America, we review and summarize existing clinical practice guidelines and recommendations concerning the prevention, diagnosis, and treatment of certain bacterial infections in dialysis patients and present four strategies to limit the spread of antimicrobial resistance in dialysis patients. First, preventing infection eliminates the need for antimicrobials, thereby reducing selection pressure for resistant strains. Efforts to prevent infection include avoidance of hemodialysis catheters, when possible, and meticulous care of hemodialysis and peritoneal catheters and other hemodialysis vascular access sites. Second, diagnosing and treating infections appropriately can facilitate the use of narrower spectrum agents, rapidly decrease the number of infecting organisms, and reduce the probability of resistance emerging. This entails the collection of indicated specimens for culture and avoidance of contamination of cultures with common skin microorganisms. Third, optimizing antimicrobial use helps protect the efficacy of such critical agents as vancomycin. Published guidelines for the use of vancomycin should be followed, and alternate agents should be used when infections with beta-lactam-resistant bacteria are unlikely or not documented. Fourth, preventing transmission in health care settings is important to limit the spread of resistant organisms. In this regard, such basic measures as glove use and hand hygiene are most important.

Nasal Carriage of Staphylococcus aureus As a Risk Factor for Skin and Soft Tissue Infections

Nasal carriage of Staphylococcus aureus is a major risk factor for the development of S. aureus infection, including skin and soft tissue infections and foreign body infections, such as catheter-associated bacteremia and peritonitis. In this article, we review the recent literature on S. aureus nasal carriage, including the emergence of methicillin- resistant S. aureus in the community, the pathophysiology of nasal carriage, and the epidemiology and prevention of S. aureus infections associated with nasal carriage.