Nasal carriage of MRSA: the role of mupirocin and outlook for resistance

Since the first attempts (1) to eradicate nasal carriage of Staphylococcus aureus with local applications of penicillin, many other topical and systemic antimicrobial agents have been tested, all with limited success. More recently, mupirocin has been much more successful and, in a controlled trial, nasal carriage of S. aureus was eliminated in all subjects and when re-colonisation eventually took place, only 29% had relapsed with their pre-treatment strain. During an MRSA outbreak at a London hospital, standard infection control measures failed to prevent colonisation and infection of more than two hundred patients, but the use of mupirocin was associated with epidemiological control. Of forty patients and thirty-two staff studied, 98.6% of staff and 90.1% of patient-weeks were free of nasal MRSA after treatment. Although resistance to at least 40 mg/l of mupirocin can be produced in vitro and resistant S. aureus have been isolated from patients undergoing prolonged skin treatment with mupirocin, there has been no evidence for the emergence of mupirocin resistance as a mechanism for the relapse of nasal carriage.     

A comparison of the new topical antibiotic mupirocin ('Bactroban') with oral antibiotics in the treatment of skin infections in general practice

A trial was carried out in general practice in 200 patients presenting with skin infections to compare topical antibiotic treatment with mupirocin ointment with orally administered flucloxacillin or erythromycin. Patients were assigned at random to receive 4 to 10 days' treatment with either mupirocin applied 3-times daily or one of the oral antibiotics in the dosage normally used by the general practitioner for skin infections. The majority of infections were impetigo and infected wounds/lacerations; the main organisms isolated initially from 127 of the patients were either Staphylococcus aureus or beta-haemolytic Group A streptococci. Clinical response to mupirocin ointment (86% cured, 13% improved) was significantly better than that seen with erythromycin (47% cured, 26% improved) and similar to that with flucloxacillin (76% cured, 23% improved). Treatment outcome was not related to treatment duration with either the topical or oral preparations. Post-treatment samples from 76 patients showed that in the mupirocin group all the pathogens originally isolated were eliminated, including Gram-negative organisms.     

Mupirocin: a topical antibiotic with a unique structure and mechanism of action

The chemistry, mechanism of action, antimicrobial activity, pharmacokinetics, clinical efficacy, adverse effects, dosage, and administration of mupirocin are reviewed. Mupirocin, formerly termed pseudomonic acid A, is a topical antibiotic under investigation for the treatment of impetigo and other superficial primary and secondary skin infections. Mupirocin (Bactroban, Beecham Laboratories) is currently formulated as a 2% ointment in a water-miscible polyethylene glycol base. The drug is a unique antimicrobial agent because of its structure and mechanism of action. Mupirocin apparently exerts its antimicrobial activity by reversibly inhibiting isoleucyl-transfer RNA, thereby inhibiting bacterial protein and RNA synthesis. Mupirocin has excellent in vitro activity against staphylococci and most streptococci but less activity against other gram-positive and gram-negative bacteria. The drug will only be used topically because of its rapid and extensive systemic metabolism. Several controlled clinical trials documented that mupirocin was significantly better than the polyethylene glycol vehicle alone or ampicillin and as effective as cloxacillin, dicloxacillin, or erythromycin in producing clinical and bacteriological cures in patients with impetigo and wound infections caused by gram-positive pathogens. Limited studies suggest that mupirocin may also have a role in eradicating nasal carriage of staphylococci. Reported adverse effects are local and may be related to the polyethylene glycol vehicle base. Mupirocin should be useful for treating patients with impetigo and wound infections caused by Staphylococcus aureus. However, additional controlled, comparative clinical studies are needed to identify the role of mupirocin in treating other primary and secondary skin infections and for eliminating nasal carriage of staphylococci.     

Antibiotics for treatment of infections caused by MRSA and elimination of MRSA carriage. What are the choices?

The widespread appearance of methicillin resistant Staphylococcus aureus (MRSA) has significantly undermined the efficacy of currently available antibiotic therapies as strains tend to be multi-resistant. Clinicians are therefore faced with a restricted choice in effective anti-MRSA therapies for infection or elimination of carriage. MRSA remain uniformly susceptible to glycopeptides vancomycin and teicoplanin which remain drugs of choice in treatment of infections. Centres with a high incidence of MRSA should use glycopeptides as empirical monotherapies against these organisms. The low toxicity of teicoplanin makes it an alternative for patients unable to tolerate vancomycin. Only mupirocin is truly effective for use as a topical agent in elimination of MRSA colonisation. For systemic use developmental glycopeptides such as daptomycin, MDL 63246, and LY191145 show better in vitro activity than vancomycin. New cephalosporins TOC-39 and FK-037 show promising anti-MRSA potential with low MICs, as does carbapenem BO-2727 which has a high in vitro activity. Whether the new cephalosporins and carbapenems with good in vitro and/or in vivo activities against MRSA will be clinically effective remains to be determined. New fluoroquinolones levofloxacin, temafloxacin and sparfloxacin have enhanced in vitro anti-MRSA activity, although the emergence of resistance, and subsequent cross resistance to related compounds during therapy is a problem. BAY 12-8039, DV-7751 and CS-940 are developmental fluoroquinolones with better in vitro activity and lower spontaneous mutation rates than related compounds. Co-trimoxazole shows good in vivo anti-MRSA activity, comparable to vancomycin, however, severe infections do not respond well and many strains are resistant to this drug. Rifampicin has excellent bactericidal activity but rapidly emerging resistance undermines its use as a monotherapy. Its use in a combination therapy offers limited potential as an alternative. Arbekacin shows good in vitro activity against many MRSA isolates, although resistance to related aminoglycosides is a problem. Streptogramins, virginiamicin and RP 59500 (dalfopristin/quinupristin), and the everninomicin SCH 27899, show excellent activity in vitro and in vivo activity against MRSA and real future potential as alternative agents to vancomycin. Azeleic acid and ramoplanin show future potential as agents for topical use against MRSA. In conclusion only vancomycin as a systemic agent and mupirocin as a topical agent, offer sufficient reliability for use against MSRA. Alternatives to glycopeptides and mupirocin rest with the development of new drugs from several classes of compounds.     

Effect of antibiotic prescribing in primary care on meticillin-resistant Staphylococcus aureus carriage in community-resident adults: a controlled observational study

The objectives of this study were to investigate the relationship between primary care antibiotics prescribed within 2 months and 12 months and the carriage of meticillin-resistant Staphylococcus aureus (MRSA) in nasal flora from a large representative sample of community-resident adults. S. aureus isolates were obtained from nasal samples submitted by UK resident adults aged ≥ 16 years registered with 12 general practices in the former Avon and Gloucestershire health authority areas. Individual-level antibiotic exposure data during the 12 months prior to providing the samples were collected from the primary care electronic records. MRSA status was determined by measuring resistance to cefoxitin. In total, 6937 adults were invited to take part, of whom 5917 returned a nasal sample. S. aureus was identified in 946 samples and a total of 761 participants consented to primary care record review and had complete data for the analyses. There was no evidence of an association between any antibiotic in the previous 2 months and MRSA isolation, with an adjusted odds ratio (aOR) of 1.33 [95% confidence interval (CI) 0.12-15; P=0.8]. There was a suggestion of an association between any antibiotic use in the previous 12 months and MRSA, with an aOR of 2.45 (95% CI 0.95-6.3; P=0.06). In conclusion, there is a suggestion that antibiotics prescribed within 12 months is associated with the carriage of MRSA, but not within 2 months, although the 2-month analysis had fewer data subjects and was therefore underpowered to detect this association. A larger study would be able to clarify these associations further.     

Does chronic hepatitis B increase Staphylococcus nasal carriage?

OBJECTIVES: To determine the prevalence of Staphylococcus aureus nasal carriage in patients with chronic hepatitis B virus infection. PATIENTS AND METHODS: The prevalence of S. aureus nasal carriage was determined in patients with chronic hepatitis B virus infection and compared with the prevalence of S. aureus nasal carriage among control patients. RESULTS: Between February 2003 and November 2004, 70 chronic hepatitis B patients and 70 control patients were enrolled in the study. S. aureus nasal carriage was shown in 15 (12%) of the patients with chronic hepatitis B and 13 (19%) of the control group (P > 0.05). There was no difference in nasal colonization between the cases and controls when analysed by age, sex, frequency of skin infection, prior use of antibiotics and hospital admission in the preceding six months. CONCLUSION: The results of our study show that chronic hepatitis B virus infection is not associated with S. aureus nasal carriage.     

Synergistic effects of mupirocin and an isoflavanone isolated from Erythrina variegata on growth and recovery of methicillin-resistant Staphylococcus aureus

The phytochemical 2',4'-dihydroxy-8-gamma,gamma-dimethylallyl-2",2"-dimethylpyrano[5",6":6,7]isoflavanone (bidwillon B) was isolated from Erythrina variegata and its antibacterial properties against methicillin-resistant Staphylococcus aureus (MRSA) were investigated. Bidwillon B inhibited the growth of 12 MRSA strains at minimum inhibitory concentrations (MICs) of 3.13-6.25mg/l, while MICs of mupirocin were 0.20-3.13 mg/l. The minimum bactericidal concentration (MBC) for bidwillon B and mupirocin against MRSA were 6.25-25mg/l (MBC(90): 12.5mg/l) and 3.13-25mg/l (MBC(90): 25mg/l), respectively. When bidwillon B and mupirocin were combined, synergistic effects were observed for 11 strains of MRSA (fractional inhibitory concentration indices, 0.5-0.75). The MBCs of mupirocin in the presence of bidwillon B (3.13 mg/l) were reduced to 0.05-1.56 mg/l. Bidwillon B at MIC values strongly inhibited incorporation of radio-labelled thymidine, uridine, glucose and isoleucine into MRSA cells. Mupirocin showed lower inhibitory effects than bidwillon B on thymidine, uridine and glucose incorporation, but incorporation of isoleucine was completely blocked with this antibiotic. These results indicate that bidwillon B possesses sufficient anti-MRSA activity for inhibiting growth and recovery, and that the compound acts synergistically with mupirocin. The results also suggest that both compounds act on MRSA via different mechanisms. Bidwillon B may prove to be a potent phytotherapeutic and/or combination agent with mupirocin in the elimination of nasal and skin carriage of MRSA.     

Susceptibility pattern of Staphylococcus aureus isolated in Malaysian hospitals

Isolates of 390 Staphylococcus aureus were tested against 13 different antibiotics by a disc diffusion method as recommended by the National Committee for Clinical Laboratory Standards (NCCLS). Strains were isolated from blood (5.7%), cerebrospinal fluid (0.5%), respiratory tract (11.8%), pus and wound (73.3%), urine (1.8%), genital specimens (1.0%) and other specimens (4.3%). Only 4.6% of the isolates were fully susceptible to all the drugs tested. Resistance to penicillin was 94.1%, methicillin, 39.7%, chloramphenicol, 8.5%, ciprofloxacin, 29.2%, clindamycin, 2.1%, erythromycin, 45.9% gentamicin, 40.5%; rifampicin, 3.3% tetracycline, 47.2%, co-trimoxazole, 38.5%, mupirocin, 2.8%, fusidic acid, 3.6%. None of the isolates was resistant to vancomycin. The susceptibility of methicillin-resistant strains to erythromycin, gentamicin, tetracycline and ciprofloxacin was low, while clindamycin, fusidic acid, mupirocin, and rifampicin remained active.     

Topical mupirocin in the treatment of bacterial skin infections

Mupirocin is an investigational topical antibiotic used for treatment and prophylaxis of bacterial skin infections. Mupirocin differs from other antibiotics in its synthesis, structure, and mechanism of action. In vitro, mupirocin possesses antimicrobial activity against staphylococci, streptococci, Hemophilus influenzae, and Neisseria gonorrhoeae. Few studies comparing mupirocin to other topical antibiotics are available. Initial studies comparing mupirocin to inactive vehicle in the treatment of impetigo indicate an overall 92 percent pathogen eradication rate with active drug and 58 percent eradication rate with vehicle. Overall response to treatment of secondary skin infections was favorable in 91 percent of patients treated with mupirocin and 77 percent of those treated with vehicle. Although incidence is not greater than placebo, adverse effects have included pruritus, burning, dry skin, and erythema. Additional trials and clinical use should further help determine the role of mupirocin in the treatment of minor, primary, and secondary skin infections.     

耐甲氧西林金黄色葡萄球菌耐药性分析

目的了解耐甲氧西林金黄色葡萄球菌(MRSA)对各种抗菌药物的耐药性。方法 对30株MRSA进行药敏实验,药敏实验采用VITEK32全自动微生物分析仪GPS药敏板。结果 在测试的14种抗菌药物中,万古霉素未出现耐药菌株,对呋喃妥因、利福平、复方磺胺甲口恶唑耐药率低(分别为6.7%、10.0%、20.0%)。对氯霉素耐药率为53.3%,对克林霉素、红霉素、庆大霉素、四环素、左氧氟沙星耐药率均在90.0%以上。对氨苄西林、头孢唑啉、苯唑西林、青霉素则是全耐药。结论 应加强抗菌药物的合理应用,减少MRSA耐药事件的发生。     

Changes in susceptibilities to teicoplanin, vancomycin and other antibiotics among Staphylococcus aureus isolates in a tertiary-care University hospital

Changes in antibiotics susceptibilities were evaluated among 374 nosocomial clinical isolates of Staphylococcus aureus collected from 1986 to 1994 in a tertiary-care University hospital where methicillin-resistant S. aureus (MRSA) is an increasing cause of infection. Significant increases in resistance to ciprofloxacin, clindamycin and rifampicin were observed among MRSA isolates in recent years. No resistance to glycopeptides was observed. However, during the last 2 years a significant trend towards a decreasing susceptibility to teicoplanin was observed among MRSA isolates.     

Mupirocin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use

Mupirocin (pseudomonic acid A) is a novel topical antibacterial agent which inhibits bacterial protein and RNA synthesis. It has excellent in vitro activity against staphylococci and most streptococci, but has less activity against other Gram-positive and most Gram-negative bacteria. Its rapid systemic metabolism means it will only be used topically which, combined with its novel chemical structure, should make cross-resistance less likely to occur than with other currently available topical antibacterial agents. Mupirocin 2% ointment administered 2 or 3 times daily has shown excellent efficacy in both primary and secondary superficial skin infections, usually with at least 80% of patients being clinically cured or markedly improved, and over 90% eradication of the bacterial pathogen involved. Efficacy in impetigo and, to a somewhat lesser extent, infected wounds has been particularly convincingly demonstrated, while in other secondary skin infections the clinical response seen with mupirocin was often similar to the high success rate of vehicle alone. Limited evidence suggests that mupirocin may be as effective as chlortetracycline, fusidic acid, neomycin and other antibacterial agents, but more controlled, comparative studies are needed. The evidence of efficacy against nasal carriage of Staphylococcus aureus, including methicillin-resistant forms, is encouraging and currently work is being undertaken to improve the acceptability of the vehicle for this use. Side effects are limited to local reactions (in less than 3% of patients) and are no more frequent than observed with the vehicle alone. Thus, mupirocin appears to be a useful addition to the agents available for the treatment of superficial primary skin infections, such as impetigo, although its precise place in therapy remains to be established.     

Designing an ultra‐short antibacterial peptide with potent activity against Mupirocin‐resistant MRSA

Staphylococcus aureus is the pathogen responsible for the majority of human skin infections. In particular, the methicillin‐resistant variety, MRSA, has become a global clinical concern. The extensive use of mupirocin, the first‐line topical antibacterial drug of choice, has led to the emergence of mupirocin‐resistant MRSA globally, resulting in the urgent need for a replacement. Antimicrobial peptides are deemed plausible candidates. Herein, we describe a structure–activity relationship approach in the design of an ultra‐short peptide with potent anti‐MRSA activity with a rapid, bactericidal mode of action. Coupled to a low cytotoxic activity, we believe our lead compound can be developed into a topical antibacterial agent to replace mupirocin as the first‐line drug for treating MRSA skin infections.     

耐甲氧西林与甲氧西林敏感金黄色葡萄球菌对复方新诺明耐药性的对比分析

目的 对比分析耐甲氧西林金黄色葡萄球菌(MRSA)与甲氧西林敏感金黄色葡萄球菌(MSSA)对复方新诺明(SXT)的耐药性.方法 对2009年1月至2012年9月临床分离的522株金黄色葡萄球菌进行分析,细菌鉴定和药敏试验采用VITEK 2 Compact全自动细菌培养鉴定仪.根据金黄色葡萄球菌对SXT耐药或敏感,分为SXT耐药(SXT-R)组和SXT敏感(SXT-S)组,比较2组MRSA和MSSA对各抗菌药物的耐药性.结果 MRSA与MSSA对万古霉素、替考拉宁、奎奴普丁/达福普汀、利奈唑胺、替加环素和呋喃妥因的耐药率均＜1.5％,且二者之间差异无统计学意义(均P＞0.05);MSSA对亚胺培南、氨苄西林/舒巴坦、利福平、莫西沙星、左旋氧氟沙星和环丙沙星的耐药率均＜9.1％,但MRSA的耐药率高达84.6％～100.0％,MSSA与MRSA比较差异有统计学意义(均P＜0.05).MRSA对SXT的耐药率[41.2％(127/308)]低于MSSA[57.9％ (114/197)],差异有统计学意义(P＜0.05).SXT-R组和SXT-S组中MRSA分离率分别为52.7％和68.6％.SXT-R组MSSA对氨苄西林/舒巴坦、亚胺培南、左旋氧氟沙星、环丙沙星、莫西沙星的耐药性低于SXT-S组[0(0.0)比25.0％ (1/4),0(0.0)比25.0％ (1/4),1.6％(1/63)比5.1％(4/79),6.1％ (7/114)比10.8％ (9/83),6.2％ (7/113)比10.8％ (9/83)],差异均有统计学意义(均P＜0.05).结论 MRSA对SXT的耐药率低于MSSA,SXT可作为治疗MRSA的可选药物之一.     

Development of a Nose Cream Containing the Synthetic Antimicrobial Peptide P60.4Ac for Eradication of Methicillin-Resistant Staphylococcus aureus Carriage

Methicillin-resistant Staphylococcus aureus (MRSA) infections are an increasing problem, and current treatment options are suboptimal. Nasal carriage of MRSA is a major risk factor for infection, but nasal eradication strategies are increasingly considered to be insufficiently effective. In this study, a water-in-oil cream formulation was developed for nasal application with an antimicrobial peptide, P60.4Ac, aimed at the eradication of MRSA carriage. Quality control of the cream included the measurement of the content and release of the peptide by a validated high-performance liquid chromatography method. Stability of the peptide in the formulation was investigated including the evaluation of the effect of stress conditions. Preliminary shelf-life study of the drug formulation demonstrated that the peptide is stable in the formulation at least for 5 months. Microbial-killing assays with MRSA LUH14616 as a target demonstrated the dose-dependent antimicrobial activity of the peptide formulation.     

儿童社区获得性肺炎耐甲氧西林金黄色葡萄球菌的耐药性及定植危险因素分析

目的:探讨我院儿童社区获得性肺炎(CAP)耐甲氧西林金黄色葡萄球菌(MRSA)的耐药性,分析呼吸道定植危险因素。方法:采用回顾性研究方法,从2012-2014年在我院住院的CAP患儿中选取痰培养检出金黄色葡萄球菌(SA)的患儿692例,根据药敏试验结果将692株SA分为社区获得性甲氧西林敏感金黄色葡萄球菌(CA-MSSA)和社区获得性MRSA(CA-MRSA)两组,检测分析SA对常用抗菌药物的耐药率,并采用Logistic回归分析方法从性别、年龄、发病地点、抗菌药物使用时间等方面分析MRSA呼吸道定植的危险因素。结果:2012-2014年我院SA检出率为7.23% (692/9569), 692株SA中MRSA 226株(32.66%)。CA-MSSA对红霉素、阿奇霉素耐药率较高;CA-MRSA对青霉素类、头孢菌素类基本耐药,对亚胺培南、阿奇霉素及克林霉素部分耐药,对利福平、复方磺胺甲唑及左氧氟沙星的耐药率较低,对万古霉素未产生耐药。CA-MRSA对常用抗菌药物的耐药率均高于CA-MSSA(P均<0.05)。低龄(<3岁)、在农村发病、长时间使用抗生素(≥7 d) 是CA-MRSA定植的危险因素。结论:基层医疗机构规范使用抗生素对控制CA-MRSA定植与感染有重要意义。我们在临床工作中应加强具有高危因素患儿的管理,及时完善细菌学检查,合理选用抗菌药物。     

Ramoplanin versus methicillin-resistant Staphylococcus aureus: in vitro experience

The authors have investigated the activity of ramoplanin against 162 isolates of MRSA from some twenty-six countries around the world. MICs were determined by the plate dilution method in isosensitest agar with an inoculum of 10(6) cfu. MBCs were measured by replication, using velvet pads, from MIC plates after 24 h incubation at 37 degrees C. Time-kill curves were determined from viable counts of cultures in Isosensitest broth (inoculum ca. 5.0 x 10(6) cfu/ml) taken at intervals during shaking culture at 37 degrees C for up to 24 h. Ciprofloxacin, mupirocin, rifampicin, teicoplanin and vancomycin were used as comparison compounds. The following MIC90 (MBC90) values (mg/l) were obtained against a selection of 60 strains: ciprofloxacin 0.8 (1.8), mupirocin 0.27 (19.0), ramoplanin 0.5 (1.0), rifampicin 0.007 (0.01), teicoplanin 1.2 (greater than 32) and vancomycin 2.2 (greater than 32.0). In time-kill experiments, ramoplanin at 20 mg/l and ciprofloxacin at 3.0 mg/l produced 99.9% killing in less than 4h. Mupirocin at 4.0 mg/l was only slowly bactericidal. No resistance was found to mupirocin, ramoplanin, teicoplanin or vancomycin in the 162 isolates tested, whereas ca. 20% resistance was found to ciprofloxacin and rifampicin. The absence of resistance, the high intrinsic activity and the rapid bactericidal effect of ramoplanin against this diverse group of MRSA are very encouraging, and suggest that clinical trials are indicated.     

An antibiotic care bundle approach based on results of rapid molecular screening for nasal carriage of methicillin-resistant Staphylococcus aureus in the intensive care unit

The potential role of active methicillin-resistant Staphylococcus aureus (MRSA) surveillance in the intensive care unit (ICU), has been recently proposed as a guide for antibiotic treatment in patients suspected of being infected with MRSA by using an antibiotic care bundle (ACB) approach. A group of 376 consecutive ICU patients were prospectively screened for nasal carriage of MRSA using a real-time polymerase chain reaction test. The study group consisted of 244 (64.9%) males and (35.1%) females, with a median age of 64 (range 17-95 years). Overall, 26 (6.9%) patients were positive for MRSA, while 350 (93.1%) were MRSA-negative. No difference was observed in gender and age between groups. During ICU stay, 9 (2.4%) patients developed generalized MRSA infection, of whom 8 out of 26 (30.8%) were MRSA-carriers and one out of the 350 (0.3%) was MRSA-negative. Thus, a strong relationship between MRSA infection and MRSA carriage (relative risk=107.7, 95% confidence interval=14.0-828.5, p<0.0001) was found. Subsequently, in our ICU, we developed and introduced a new ACB approach based on rapid nasal screening results for improving the management of critically ill patients. The use of anti-MRSA agents should be re-evaluated daily on the basis of clinical and laboratory features, with positive cultures from sterile site or signs of active infection supporting prolongation of empirical treatment. On the contrary, MRSA-negative clinical cultures support a de-escalation strategy. In conclusion, the early identification of MRSA-carriers using a rapid molecular screening is safe and accurate, allowing MRSA-positive patients, who will more likely develop MRSA infections, to be detected.     

Impact of rifampicin addition to clarithromycin in Legionella pneumophila pneumonia

We evaluated the effectiveness and safety of rifampicin addition to clarithromycin in the treatment of Legionnaires' disease. An observational cohort study was conducted on patients assigned to a Legionnaires' disease outbreak. Of 32 patients with confirmed Legionella pneumonia, 11 received clarithromycin monotherapy and 21 received combination therapy of clarithromycin with rifampicin. Both groups had similar baseline characteristics and all patients were cured. Patients who received rifampicin had a 50% longer length of stay (P=0.035) and a trend towards higher bilirubin levels (P=0.053). Length of stay was directly correlated with the duration of rifampicin treatment (P=0.001). Combination therapy of clarithromycin and rifampicin had no additional benefit compared with clarithromycin monotherapy and could prolong the length of stay owing to possible negative drug interactions that could also affect other antibiotics.     

Agents for the Decolonization of Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) bacteria are a common cause of hospital- and community-acquired infections. Persons may have asymptomatic colonization with MRSA in the nares, axillae, perineum, or groin. Since MRSA colonization often precedes infection, and infection is associated with significant morbidity and mortality, there is great interest in preventing the transmission of MRSA and decolonizing persons who harbor these bacteria. We provide an evidence-based review of MRSA decolonization agents. Our search strategy included the databases of the Cochrane Central Register of Controlled Trials, MEDLINE (1962-May 2008), and EMBASE (1980-May 2008). To identify unpublished trials, abstract books from appropriate major scientific meetings were hand searched, manufacturers were contacted, and pharmacology references were researched for available commercial products, formulations, adverse events, and dosing. The most extensive research in MRSA decolonization has been conducted with mupirocin, which is applied to the anterior nares 2–3 times/day for 5 days. Increased use is correlated to resistance development; therefore, routine decolonization is not prudent unless MRSA colonization is confirmed in the nares or other site. Retapamulin is under investigation for use in nares decolonization. If total body decolonization is necessary, bathing or showering with an antiseptic agent such as chlorhexidine gluconate is recommended in combination with mupirocin applied to the nares to improve the likelihood of eradication. Oral antibiotics have been evaluated for use in decolonization of the skin and nares but should be considered only in conjunction with topical agents and when all other decolonization attempts and environmental controls have been exhausted. Homeopathic and investigational agents may also be effective. Although mupirocin is the standard of care for decolonization of MRSA, several agents demonstrate efficacy and many merit further investigation.