The use of nasal mupirocin ointment to prevent Staphylococcus aureus bacteraemias in haemodialysis patients: an analysis of cost-effectiveness

Effective screening methods to prevent surgical site infections in orthopedic surgery: an observational study

BACKGROUND

The bacterial source of surgical-site infections (SSIs) can have either endogenous and/or exogenous origins, and some studies have revealed that endogenous transmission is an important pathway for SSIs in orthopedic surgery. However, since the frequency of SSIs is low (0.5-4.7%), screening all surgery patients is labor-intensive and cost-prohibitive. The goal of this study was to better understand how to improve the efficacy of nasal culture screening in preventing SSIs.

METHODS

Nasal cultures for 1616 operative patients over a 3-year period were evaluated for the presence of nasal bacterial microbiota and the species identity. We also investigated the medical factors that influence colonization and evaluated the ratio of agreement between nasal cultures and SSI-causing bacteria.

RESULTS

In a survey of 1616 surgical cases, 1395 (86%) were normal microbiota (NM), 190 (12%) were MSSA carriers, and 31 (2%) were MRSA carriers. The risk factors for MRSA carriers were significantly higher than the NM group in patients with a history of hospitalization (13 [41.9%], p = 0.015), patients who had been admitted to a nursing facility (4 [12.9%], p = 0.005), and patients who were > 75 years of age (19 [61.3%], p = 0.021). The incidence of SSIs was significantly higher in the MSSA group (17/190 [8.4%]) than the NM group (10/1395 [0.7%], p = 0.00). The incidence of SSIs in the MRSA group (1/31 [3.2%]) tended to be higher than that in the NM group, but there was no statistically significant difference (p = 0.114). The concordance rate between causative bacteria of SSI and species present in nasal cultures was 53% (13/25 cases).

CONCLUSIONS

The results of our study suggest screening patients with a history of past hospitalization, a history of admission in a long-term care facility, and older than 75 to reduce SSIs.

TRIAL REGISTRATION

This study was approved by the institutional review board of the authors' affiliated institutions (the ethics committee of Sanmu Medical Center, 2016-02).

Treatment of dialysis catheter infections in 2004

Hemodialysis catheter associated infections are a major source of morbidity and mortality in end stage renal disease patients. There is disagreement about the management of catheter infections, particularly concerning the removal of potentially infected tunneled dialysis catheters. A dialysis catheter should generally be removed when an infection involves a temporary hemodialysis catheter, a septic patient, a patient with a tunnel tract infection, or a patient with evidence of a metastatic infectious complication. In treating stable patients with clinically mild catheter associated bacteremia, parenteral antibiotics alone have a low success rate in eliminating the infection. Antibiotic locks are an emerging strategy for treating these patients, but at present higher rates of success and lower costs are achieved by exchanging the catheter over a guidewire. Antibiotic lock solutions, antibiotic coated catheters, and totally implantable dialysis access systems may play a large role in prevention of catheter associated infections in the future; however, further randomized controlled trials of these strategies are needed. Future efforts should concentrate on limiting the use of traditional tunneled cuffed hemodialysis catheters by early referral to vascular surgery for the creation of an arterio-venous fistula.

Impact of Staphylococcus aureus protein A (spa) genetic typing in cases of prosthetic shunt graft infections

INTRODUCTION

In January 2014 an internal audit was performed at the department of surgery, division of vascular surgery of the Medical University Graz, Austria, to assess the short and long-term outcomes of prosthetic shunt graft implantations performed between December 1998 and December 2013. A 10.8 % explantation rate due to graft infection was detected. The majority of the cases were associated with Staphylococcus aureus. The aim of this study was to clarify whether this constitutes a nosocomial problem.

PATIENTS AND METHODS

Between December 1998 and December 2014 a total of 490 prosthetic shunt grafts were implanted. After exclusion of 54 cases, 436 shunts remained for statistical analysis. Genetic analysis (spa typing) was acquired from three new cases with involvement of S. aureus in 2014. The impact of several factors (e.g. sex, institute for dialysis, age, type of prosthesis, implantation surgeon and position of shunt) on the shunt graft infection rate was statistically analyzed.

RESULTS

Of the prostheses 14.0 % (61 out of 436) had to be explanted of which 12.4 % (54/436) were due to infection. In 77.8 % (42/54) bacteria were found in blood and/or wound cultures. Staphylococcus aureus was present in 76.2 % (32/42) of the cases with detected bacteria and in all cases was sensitive to methicillin. The infection rate was not significantly dependent on any of the investigated factors; however, the factor "institute for dialysis" had a remarkable p‑value of 0.060 with the infection rate ranging from 8.5 % to 18.2 % depending on the institution. Three different S. aureus protein A (spa) types were found: t015, t359, t6265. The detection of three different spa types means that these patients had different sources of S. aureus so that a nosocomial problem is very unlikely.

CONCLUSION

Genetic typing of spa is a suitable technique for distinguishing between nosocomial and community acquired sources of prosthetic shunt graft infections.

Clinical Effectiveness of Mupirocin for Preventing Staphylococcus aureus Infections in Nonsurgical Settings: A Meta-analysis

A systematic literature review and meta-analysis was performed to identify effectiveness of mupirocin decolonization in prevention of Staphylococcus aureus infections, among nonsurgical settings. Of the 15 662 unique studies identified up to August 2015, 13 randomized controlled trials, 22 quasi-experimental studies, and 1 retrospective cohort study met the inclusion criteria. Studies were excluded if mupirocin was not used for decolonization, there was no control group, or the study was conducted in an outbreak setting. The crude risk ratios were pooled (cpRR) using a random-effects model. We observed substantial heterogeneity among included studies (I(2) = 80%). Mupirocin was observed to reduce the risk for S. aureus infections by 59% (cpRR, 0.41; 95% confidence interval [CI], .36-.48) and 40% (cpRR, 0.60; 95% CI, .46-.79) in both dialysis and nondialysis settings, respectively. Mupirocin decolonization was protective against S. aureus infections among both dialysis and adult intensive care patients. Future studies are needed in other settings such as long-term care and pediatrics.

Multidrug-resistant organisms in dialysis patients

Multidrug-resistant organisms (MDROs) have emerged as important causes of healthcare-associated infections (HAIs), and these infections are associated with significant morbidity and mortality. Dialysis patients have been particularly affected by these pathogens, with colonization and infection rates often exceeding those seen in persons with other types of healthcare exposure. The infection control practices that are currently recommended for use in dialysis facilities and other healthcare settings have the potential to eliminate, or at least substantially reduce transmission of and infection with MDROs. Unfortunately, recent data suggest that these recommended practices are not consistently implemented. Additional efforts and research are needed to increase healthcare workers' awareness of and adherence to infection prevention measures, to develop new and more effective prevention strategies, and to determine cost-effective approaches to MDRO prevention to optimize the safety and quality of care provided to dialysis patients.

Epidemiology and prevention of Staphylococcus aureus nasal carriage in hemodialyzed patients

Nasal carriage of Staphylococcus aureus may be responsible for some serious infections among hemodialyzed patients. Its pathogenic potential and commensal nature allows for an easy transmission both in and out of hospital environment.

PURPOSE

This study was to assess the prevalence of S. aureus nasal carriage, to determine its frequency and nature in hemodialyzed patients of the Rabat Ibn Sina University hospital, in Morocco.

PATIENT AND METHOD

The study began in March 2008 according to the following protocol: screening of nasal carriage with five samplings, performed once a month three times, then once a month two times again after an interruption period of three months. Screening was performed weekly during the first month in hemodialyzed patients treated with mupirocin (Bactroban(®) 2%), and then monthly, to monitor the kinetics of S. aureus eradication.

RESULTS

The study included 54 hemodialyzed patients with a mean 44.16±14 years of age, sex ratio of 0.54, and mean hemodialysis duration of 118.7±67 months. Permanent and intermittent S. aureus carriage was found in respectively 18.52% and 25.92% of patients. Eighty-one strains of S. aureus were identified, 14.81% of which were methicillin resistant. Eradication was sustained beyond 20 months in patients treated with mupirocin.

CONCLUSION

This investigation allowed us to identify hemodialyzed patients at risk, so as to implement the rules of individual and collective hygiene, and to extend mupirocin antibiotic prophylaxis in our hemodialysis unit.

Staphylococcus aureus nasal carriage among the diabetic and non-diabetic haemodialysis patients

Staphylococcus aureus is the most common cause of serious infections in patients undergoing long-term haemodialysis (HD). S. aureus infections in HD patients are associated with considerable morbidity and mortality. Especially, methicillin-resistant S. aureus (MRSA) strains are becoming increasingly multidrug-resistant and have recently developed resistance to vancomycin, used successfully to treat MRSA for more than 30 years. In vitro determination of resistance patterns of S. aureus is critical in terms of administering suitable antimicrobial treatment. The objective of this study was to identify the frequency of S. aureus among diabetic and non-diabetic HD patients and to investigate resistance patterns against various antibiotics used broadly for treatment. This study was carried out between January 2004 and December 2004. In the present survey, 261 patients undergoing HD treatment from three HD units in Hatay were examined. A total of 148 Staphylococcus aureus strains were processed to assess their occurrence rates and antimicrobial susceptibility profiles. S. aureus positivity was determined in 148 (56.7%) of the 261 HD patients and 26 (16.2%) of the 160 individuals in the control group. The difference was significant (p < 0.001). HD length was found to be 38.4 +/- 24.3 months in the patients of S. aureus carrier and 27.3 +/- 18.5 months in non-carrier patients. Significant correlation was also identified between durations those on HD and the isolation of S. aureus (p < 0.001). However, the carrier state was unrelated to the presence of diabetes mellitus (DM), age or sex. In conclusion, nasal carriage of S. aureus was found to be more prevalent in HD patients than that in those in the control group. Also, it is concluded that DM was not a risk factor for the nasal carriage of S. aureus. In addition, the rates of antibiotic resistance of S. aureus strains were found to be quite higher in HD patients than in the control group (p < 0.05).

The role of nasal carriage in Staphylococcus aureus infections

Staphylococcus aureus is a frequent cause of infections in both the community and hospital. Worldwide, the increasing resistance of this pathogen to various antibiotics complicates treatment of S aureus infections. Effective measures to prevent S aureus infections are therefore urgently needed. It has been shown that nasal carriers of S aureus have an increased risk of acquiring an infection with this pathogen. The nose is the main ecological niche where S aureus resides in human beings, but the determinants of the carrier state are incompletely understood. Eradication of S aureus from nasal carriers prevents infection in specific patient categories-eg, haemodialysis and general surgery patients. However, recent randomised clinical trials in orthopaedic and non-surgical patients failed to show the efficacy of eliminating S aureus from the nose to prevent subsequent infection. Thus we must elucidate the mechanisms behind S aureus nasal carriage and infection to be able to develop new preventive strategies. We present an overview of the current knowledge of the determinants (both human and bacterial) and risks of S aureus nasal carriage. Studies on the population dynamics of S aureus are also summarised.

Prevention of Staphylococcus aureus infections among surgical patients: Beyond traditional perioperative prophylaxis

BACKGROUND

Health care-related infections cause significant patient morbidity and mortality rates and add excess costs that frequently are not reimbursed. Staphylococcus aureus has long been recognized as an important pathogen in human disease and is the most common cause of nosocomial infections.

METHOD

The objective of this review of the English language literature and a MEDLINE search was to describe recent advances in the prevention of S aureus health care-related infections that are attributable to patients' endogenous colonization. The ecologic niche of S aureus is the anterior nares and nasal carriage increases the risk of the development of a surgical-site, lower respiratory tract, or bloodstream infection. S aureus carriers have a 2- to 9-fold increased risk of the development of a surgical-site or intravenous catheter infection.

RESULTS

Three treatment strategies may eliminate nasal carriage: locally applied antibiotics or disinfectants, systemic antibiotics, and bacterial interference. Among these strategies, locally applied or systemic antibiotics are used most commonly. Nasal ointments or sprays and oral antibiotics have variable efficacy, and their use frequently results in antimicrobial resistance among S aureus strains. Of the commonly used agents, mupirocin (pseudomonic acid) ointment has been shown to be 97% effective in reducing S aureus nasal carriage. In a recently published randomized, double-blind, placebo-controlled trial to determine whether intranasal mupirocin reduced the rate of S aureus-infected surgical-site and other S aureus health care-related infections; 4% of S aureus nasal carriers who received mupirocin acquired S aureus health care-related infections compared with 7.7% of S aureus nasal carriers who received placebo (P=.02). The S aureus surgical-site infection rate was not reduced significantly, but carriers who received mupirocin before cardiothoracic or general surgery operations had almost 50% fewer S aureus surgical-site infections than carriers who received placebo. In this setting resistance rarely has been reported.

CONCLUSIONS

Given the importance of S aureus nosocomial infections and the increased risk of S aureus nasal carriage in patients with health care-related infections, investigators must study cost-effective strategies to further prevent certain types of health care-related infections or nosocomial infections that occur in specific settings. One potential strategy is to decrease or eliminate S aureus nasal carriage among certain patient populations or in certain healthcare settings.

Intranasal mupirocin to prevent postoperative Staphylococcus aureus infections

BACKGROUND

Patients with nasal carriage of Staphylococcus aureus have an increased risk of surgical-site infections caused by that organism. Treatment with mupirocin ointment can reduce the rate of nasal carriage and may prevent postoperative S. aureus infections.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial to determine whether intranasal treatment with mupirocin reduces the rate of S. aureus infections at surgical sites and prevents other nosocomial infections.

RESULTS

Of 4030 enrolled patients who underwent general, gynecologic, neurologic, or cardiothoracic surgery, 3864 were included in the intention-to-treat analysis. Overall, 2.3 percent of mupirocin recipients and 2.4 percent of placebo recipients had S. aureus infections at surgical sites. Of the 891 patients (23.1 percent of the 3864 who completed the study) who had S. aureus in their anterior nares, 444 received mupirocin and 447 received placebo. Among the patients with nasal carriage of S. aureus, 4.0 percent of those who received mupirocin had nosocomial S. aureus infections, as compared with 7.7 percent of those who received placebo (odds ratio for infection, 0.49; 95 percent confidence interval, 0.25 to 0.92; P=0.02).

CONCLUSIONS

Prophylactic intranasal application of mupirocin did not significantly reduce the rate of S. aureus surgical-site infections overall, but it did significantly decrease the rate of all nosocomial S. aureus infections among the patients who were S. aureus carriers.

Infectious complications of the hemodialysis access

Infectious complications of the vascular access are a major source of morbidity and mortality among hemodialysis (HD) patients. Numerous reports implicate the vascular access in up to 48 to 73% of all bacteremias in HD patients. The incidence of vascular access-related infection is highest when central venous dialysis catheters are employed. Native arteriovenous fistulas carry the lowest risk of infection. Unfortunately, prosthetic arteriovenous grafts, which represent the most common type of HD access in the United States, have been repeatedly shown to be a risk factor for bacteremic and nonbacteremic infections. Silent infection in old nonfunctional clotted prosthetic arteriovenous grafts has recently been recognized as a frequent cause of bacteremia and morbidity among HD patients. High proportions of infections related to the vascular access are caused by staphylococcal organisms, which carry high rates of mortality, recurrence, and metastatic complications. Management of vascular access-related infection has two aspects: The first relates to the choice, duration, and mode of administration of antibiotic therapy. Empiric antibiotic therapy, guided by demographic data and severity of illness, should be employed when the causative organisms are unknown. Prolonged administration of specific parenteral antibiotics is crucial in decreasing complications of infection, especially in cases of staphylococcal bacteremia. The second aspect relates to management of the vascular access. Efforts directed toward bacteriological cure should be concurrent with efforts to preserve native venous access sites whenever possible. Efforts to prevent vascular access-related infection should focus on increasing placement of arteriovenous fistulas and minimizing insertion of central venous dialysis catheters. Careful inspection and monitoring of the vascular access is of paramount importance in early detection of vascular access site-related infections. Several new approaches aimed at preventing catheter and prosthetic graft-related infection are being explored.

Opportunities for mupirocin calcium cream in the emergency department

Mupirocin calcium cream is a newly reformulated topical antibiotic with a bactericidal spectrum specific for the pathogens that frequently cause secondary infections in superficial wounds. Both the calcium cream and ointment formulations have demonstrated efficacy in the treatment of secondarily infected traumatic lesions and dermatoses, including eczema, burns, wounds, bites, and ulcers. Mupirocin has a low risk of systemic and topical complications. To date, antimicrobial resistance is rare among target pathogens. The use of mupirocin to treat secondary wound infection has a profile of high efficacy and does not impair the normal healing in traumatized skin.

Prophylactic mupirocin could reduce orthopedic wound infections. 1,044 patients treated with mupirocin compared with 1,260 historical controls

We analyzed the effect of perioperative elimination of nasal carriage of Staphylococcus aureus using mupirocin nasal ointment on the reduction of the postoperative wound infection rate in orthopedics. In an unblinded intervention trial, we compared 1,044 patients treated with mupirocin (intervention group) with 1,260 historical controls (control group). From each group a random sample of 50 patients was taken. Risk factors were analyzed in these random samples and we found it unlikely that different distributions of risk factors might have influenced the results. The wound infection rates were 14/1,044 in the intervention group and 34/1,260 in the control group (p = 0.02). The rates of wound infections caused by S. aureus were subsequently 7/1,044 and 14/1,260 (p = 0.3). On checking the data we found that prophylaxis had unintentionally not been given to 172 patients in the intervention group. Correction of the data gave a comparable total infection rate, but a further reduced infection rate by S. aureus. Our findings suggest that prophylactic treatment with mupirocin in orthopedic surgery can reduce the infection rate.

New approaches to reduce Staphylococcus aureus nosocomial infection rates: treating S. aureus nasal carriage

BACKGROUND

Nosocomial infections cause significant patient morbidity and mortality. The 2.5 million nosocomial infections that occur each year cost the US healthcare system $5 million to $10 million. Staphylococcus aureus has long been recognized as an important pathogen in human disease and is the most common cause of nosocomial infections.

OBJECTIVE

To describe the epidemiology of S. aureus nosocomial infections that are attributable to patients' endogenous colonization.

DATA SOURCES

Review of the English-language literature and a MEDLINE search (as of September 1997).

DATA SYNTHESIS

The ecologic niche of S. aureus is the anterior nares. The prevalence of S. aureus nasal carriage is approximately 20-25%, but varies among different populations, and is influenced by age, underlying illness, race, certain behaviors, and the environment in which the person lives or works. The link between S. aureus nasal carriage and development of subsequent S. aureus infections has been established in patients on hemodialysis, on continuous ambulatory peritoneal dialysis, and those undergoing surgery. S. aureus nasal carriers have a two-to tenfold increased risk of developing S. aureus surgical site or intravenous catheter infections. Thirty percent of 100% of S. aureus infections are due to endogenous flora and infecting strains were genetically identical to nasal strains. Three treatment strategies may eliminate nasal carriage: locally applied antibiotics or disinfectants, systemic antibiotics, and bacterial interference. Among these strategies, locally applied or systemic antibiotics are most commonly used. Nasal ointments or sprays and oral antibiotics have variable efficacy and their use frequently results in antimicrobial resistance among S. aureus strains. Of the commonly used agents, mupirocin (pseudomonic acid) ointment has been shown to be 97% effective in reducing S. aureus nasal carriage. However, resistance occurs when the ointment has been applied for a prolonged period over large surface areas.

CONCLUSIONS

Given the importance of S. aureus nosocomial infections and the increased risk of S. aureus nasal carriage in patients with nosocomial infections, investigators need to study cost-effective strategies to prevent certain types of nosocomial infections or nosocomial infections that occur in specific settings. One potential strategy is to decrease S. aureus nasal carriage among certain patient populations.

Nosocomial Staphylococcus aureus bacteremia among nasal carriers of methicillin-resistant and methicillin-susceptible strains

OBJECTIVES

To determine the relevance of nasal carriage of Staphylococcus aureus, either methicillin-sensitive (MSSA) or methicillin-resistant (MRSA), as a risk factor for the development of nosocomial S aureus bacteremia during an MRSA outbreak.

PATIENTS AND METHODS

In this prospective cohort study, 488 patients admitted to an intensive care unit (ICU) during a 1-year period were screened with nasal swabs within 48 hours of admission and weekly thereafter in order to identify nasal S aureus carriage. Nasal staphylococcal carriers were observed until development of S aureus bacteremia, ICU discharge, or death.

RESULTS

One hundred forty-seven (30.1%) of 488 patients were nasal S aureus carriers; 84 patients (17.2%) harbored methicillin-sensitive S aureus; and 63 patients (12.9%) methicillin-resistant S aureus. Nosocomial S aureus bacteremia was diagnosed in 38 (7.7%) of 488 patients. Rates of bacteremia were 24 (38%) of the MRSA carriers, eight (9.5%) of the MSSA carriers, and six (1.7%) of noncarriers. After adjusting for other predictors of bacteremia by means of a Cox proportional hazard regression model, the relative risk for S aureus bacteremia was 3.9 (95% confidence interval, 1.6-9.8; P = 0.002) for MRSA carriers compared with MSSA carriers.

CONCLUSIONS

Among ICU patients, nasal carriers of S aureus are at higher risk for S aureus bacteremia than are noncarriers; in the setting of an MRSA outbreak, colonization by methicillin-resistant strains represents a greater risk than does colonization by MSSA and strongly predicts the occurrence of MRSA bacteremia.

The significance of nasal carriage of Staphylococcus aureus and the incidence of postoperative wound infection

Staphylococcus aureus infections are associated with considerable morbidity and, in certain situations, mortality. The association between the nasal carriage of S. aureus and subsequent infection has been comprehensively established in a variety of clinical settings, in particular, patients undergoing haemodialysis and continuous ambulatory peritoneal dialysis (CAPD), and in patients undergoing surgery. Postoperative wound infections are associated with a high degree of morbidity and represent an important medical issue. Until recently, eradication of S. aureus nasal carriage by various topical and systemic agents had proved unsuccessful. Mupirocin is a novel topical antibiotic with excellent antibacterial activity against staphylococci. Recent studies have demonstrated that intranasal administration of mupirocin is effective in eradicating the nasal carriage of S. aureus and in reducing the incidence of S. aureus infections in haemodialysis and CAPD patients. It has been suggested that sufficient evidence now exists to test the hypothesis that eradication of the carrier state in surgical patients preoperatively may reduce the incidence of S. aureus postoperative wound infections.

Nasal carriage of Staphylococcus aureus and cross-contamination in a surgical intensive care unit: efficacy of mupirocin ointment

A six month prospective study was carried out in a surgical intensive care unit (SICU) of a university hospital to assess the incidence and routes of exogenous colonization by Staphylococcus aureus. A total of 157 patients were included in the study. One thousand one hundred and eleven specimens (nasal, surgical wound swabs, tracheal secretions obtained on admission and once a week thereafter, and all clinical specimens) were collected over a four month period from patients without nasal decontamination (A). They were compared with 729 specimens collected over a two month period from patients treated with nasal mupirocin ointment (B). All S. aureus strains were typed by restriction fragment length polymorphism (RFLP) pulsed-field gel electrophoresis after SmaI macrorestriction. The nasal colonization rates on admission were 25.5 and 32.7% in groups A and B, respectively. Thirty-one untreated patients (31.3%) and three patients (5.1%) treated with nasal ointment, acquired the nasal S. aureus in the SICU (P = 0.00027). Nasal carriers were more frequently colonized in the bronchopulmonary tract (Bp) and surgical wound (Sw) (62%) than patients who were not nasal carriers (14%) (P < 0.00001). The patterns were identical for nasal, Bp and Sw strains from the same patient. RFLP analysis characterized seven epidemic strains of methicillin-resistant S. aureus (MRSA) which colonized 60% of group A and 9% of group B patients (P < 0.00001). The bronchopulmonary tract infection rate was reduced in group B (P = 0.032). In conclusion, in an SICU, nasal carriage of S. aureus appeared to be the source of endogenous and cross-colonization. The use of nasal mupirocin ointment reduced the incidence of Bp and Sw colonization, as well as the MRSA infection rate.

Mupirocin resistance among consecutive isolates of oxacillin-resistant and borderline oxacillin-resistant Staphylococcus aureus at a university hospital

Mupirocin resistance was determined in consecutive oxacillin-resistant and borderline oxacillin-resistant Staphylococcus aureus clinical isolates collected over 14 months at a university hospital during 1991 and 1992. Twenty of 86 (23%) oxacillin-resistant and borderline oxacillin-resistant S. aureus isolates were mupirocin resistant; 80% were high-level resistant. Prior mupirocin use was a significant risk factor (relative risk, 6.08; 95% confidence interval, 3.7 to 9.99). Seven of 20 resistant isolates were distinct strains, as determined by pulsed-field gel electrophoresis typing. Two instances of clonal dissemination of a single strain occurred, but several other distinct mupirocin-resistant strains were documented. Mupirocin resistance was unexpectedly common among these isolates.

Treatment of Staphylococcus aureus nasal carriers in continuous ambulatory peritoneal dialysis with mupirocin: long-term results

We present the clinical results of a prospective protocol of the treatment of Staphylococcus aureus nasal carriers (SANCs) in our continuous ambulatory peritoneal dialysis unit with mupirocin (Bactroban, SmithKline Beecham Pharmaceuticals, Philadelphia, PA). We monitored the incidence of peritonitis and catheter exit-site infection, the rate of infection-related catheter loss, and the degree of association between SANC state and S aureus infection. The study group included 94 patients with a follow-up of 1,097 patient-months (phase B). The same information was retrospectively collected among 74 continuous ambulatory peritoneal dialysis patients treated during the 24 months preceding the study period (follow-up of 1,043 patient-months) (phase A). S aureus nasal carriage was observed in 47.5% of the patients. Mupirocin was very effective in eradicating S aureus from the nares, but most patients required periodic retreatment. The incidence of S aureus peritonitis decreased from 1 episode/58 patient-months in phase A to 1 episode/548 patient-months in phase B, and the incidence of exit-site infection decreased from one episode/55 patient-months in phase A to 1 episode/137 patient-months in phase B. However, there was a simultaneous increase in the incidence of infections by other gram-positive and -negative bacteria. The rate of catheter loss after peritonitis (P = not significant) or exit-site infection (P < 0.05) tended to decrease from phase A to phase B. Seventy-seven percent of the peritonitis infections and 74% of the exit-site infections by S aureus occurred in SANCs.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of a broad-spectrum antibiotic (mupirocin) in an in vitro model of infected skin

The microbicidal effect of mupirocin (Bactroban) was studied using an in vitro model of burn eschar in contact with this antimicrobial cream, to indicate its inhibiting action after 1, 2, 4, and 24 h. The microorganisms used were 20 isolates of Ps. aeruginosa, 20 isolates of MRSA, 10 isolates of Staph. epidermidis, 12 isolates of Enterobacteriaceae and eight isolates of Candida albicans. There was a marked effect on Gram-negative bacilli (< 0.1 per cent surviving) by 4 h, whereas on Gram-positive organisms its effect was slower, principally on MRSA with 2.2 per cent survivors by 24 h. The action on Candida was very slow initially, but after 24 h, the mupirocin's effect was marked (< 0.1 per cent survivors). The studies showed that mupirocin (a topical broad-spectrum antimicrobial agent) can be used in vitro against Gram-positive and Gram-negative bacteria and yeasts, which contaminate skin and mucosa. Further clinical experience is required before mupirocin can be used to treat colonized or infected wounds in burned patients.