Mupirocin Research Articles

Film Forming, Antimicrobial and Growth Promoting Wound Healing Spray Formulation

Background: Bacterial infections at wound site are one of the major causes for delayed healing. The aim of this study was to develop topical film forming spray having Combination of Simvastatin and Mupirocin which can avoid such infections and provide enhanced wound healing. Methods: Film forming spray formulation having Simvastatin and Mupirocin was formulated using Eudragit E100as film forming agent and Glycerol and Polyethylene glycol (PEG-400) as plasticizers. The effect of these excipients on the formulation was assessed by applying factorial design. Optimized formulation was evaluated for swelling index, spray angle, spray pattern, invitro drug release, evaporation time, average weight per dose, antimicrobial efficacy and in-vivo wound healing was assessed and compared with marketed formulation by excision wound healing model. Results: The optimized batch of topical film forming spray having combination of Simvastatin and Mupirocin was selected based on the results of swelling index and in-vitro drug release at respective drugs. Both the drugs gave more than 80% of drug release within 2 hrs and showed satisfactory physicochemical and mechanical properties along with potent antimicrobial efficacy against S. aureus and E. coli. Developed formulation showed comparative wound healing activity as that of marketed conventional formulation. Conclusion: Topical film forming spray was successfully developed using combination of Simvastatin and Mupirocin Calcium. Antimicrobial activity and results of animal studies indicated safety and efficacy of formulation.

Impact of formulary interventions on the minimum inhibitory concentration of methicillin-resistant Staphylococcus aureus to mupirocin, chlorhexidine, and octenidine in a Singapore tertiary institution.

Methicillin-resistant Staphylococcus aureus (MRSA) decolonization is an effective measure to prevent clinical infection but resistance is a concern. We aim to evaluate the impact of mupirocin (MUP) ointment formulary removal, plateauing use of chlorhexidine gluconate (CHG), and hospital-wide introduction of octenidine (OCT)-based products on the minimum inhibitory concentration (MIC) of MRSA to MUP, CHG, and OCT in our hospital. A prevalence study was conducted at three time points (TP) on consecutive MRSA screening isolates to evaluate for their MICs to MUP, CHG, and OCT using broth microdilution sensititre plates and detection of the ileS-2 gene encoding high-level MUP resistance in 2013 (pre-intervention TP1; n = 160), 2016 (early post-intervention TP2; n = 99) and 2017 (late post-intervention TP3; n = 76). Statistical analyses were performed using Chi square test with reference from TP1. There was a significant improvement in MUP susceptibility (MIC < 4 mcg/ml) from 71.9% (TP1) to 86.9% (TP2; p = 0.006) to 88.2% (TP3; p = 0.007). The prevalence of MUP high-level resistance (MIC > 256 mcg/ml) reduced from 25.0% (TP1) to 12.1% (TP2; p = 0.014) to 5.3% (TP3; p = 0.001). Likewise, the prevalence of isolates harboring the ileS-2 gene decreased from 28.1% (TP1) to 18.2% (TP2; p = 0.072) to 9.2% (TP3; p = 0.002). OCT MIC range remains stable at 0.5 to 1 mcg/ml across all three TPs. The proportion of isolates with reduced CHG susceptibility (MIC ≥ 4 mcg/ml) increased over the three TPs from 23.1 to 27.2% (p = 0.45) to 42.1% (p = 0.003). Active formulary regulations have an impact on the resistance profile of MRSA and can be used as a strategy to preserve the MRSA decolonization armamentarium.

Prevalence and molecular characterization of methicillin-resistant Staphylococcus aureus with mupirocin, fusidic acid and/or retapamulin resistance

BackgroundThe data on the prevalence of resistance to mupirocin (MUP), fusidic acid (FA) and retapamulin (RET) in methicillin-resistant Staphylococcus aureus (MRSA) from China are still limited. This study aimed to examine these three antibiotics resistance in 1206 MRSA clinical isolates from Eastern China. Phenotypic MUP, FA and RET resistance was determined by minimum inhibitory concentrations (MICs), and genotypic by PCR and DNA sequencing of the mupA/B, fusB-D, cfr, vgaA/Av/ALC/B/C/E, lsaA-C/E and salA and mutations in ileS, fusA/E, rplC, and 23S RNA V domain. The genetic characteristics of resistance isolates were conducted by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).ResultsOverall MRSA MUP, FA and RET resistance was low (5.1, 1.0 and 0.3%, respectively). MupA was the mechanism of high-level MUP resistance. All low-level MUP resistance isolates possessed an equivocal mutation N213D in IleS; of these, 2 reported an additional V588F mutation with an impact on the Rossman fold. FusA mutations, such as L461K, H457Q, H457Y and V90I were the primary FA mechanisms among high-level resistance isolates, most of which also contained fusC; however, all low-level resistance strains carried fusB. Except lsaE gene detected in one isolate, no other resistance mechanisms tested were found among RET-resistant isolates. Additionally, sixteen PFGE types (A-P) were observed, among which type B was the most common (49/76, 64.5%), followed by types E and G (4/76, 5.3% each) and types C and M (3/76, 3.9% each). All resistant strains were divided into 15 ST types by MLST. ST764 (24/76, 31.6%), ST630 (11/76, 14.5%), ST239 (9/76, 11.8%) and ST5 (7/76, 9.2%) were the major types. PFGE type B isolates with the aforementioned STs were mainly found in mupirocin resistant isolates.ConclusionsMUP, FA and RET exhibited highly activity against the MRSA isolates. Acquired genes and chromosome-borne genes mutations were responsible for MUP and FA resistance; however, the mechanism for some RET-resistant isolates remains to be further elucidated. Also, the surveillance to MUP in MRSA should be strengthened to prevent elevated resistance due to the expansion of clones.

Safety and Efficacy of Mupirocin Gel in Children With Impetigo

Safety and Efficacy of Mupirocin Gel in Children With Impetigo

Significance, epidemiology, and prevention of peritoneal dialysis catheter infections.

Catheter infections are a major cause of morbidity, catheter loss, and transfer to hemodialysis. These infections are mainly due to S. aureus. To date, treatment is less than optimal. Therefore, the primary goal should be prevention of catheter infections. Prevention is based on improving catheter design and implantation technique while using careful exit-site care. Prophylaxis with antimicrobials such as intranasal mupirocin or the use of silver-impregnated catheters appears promising as a way to reduce the risk of developing S. aureus infections. To optimize patient outcome, one must focus on these preventive measures.

Iron Sequestrant DIBI, a Potential Alternative for Nares Decolonization of Methicillin-Resistant Staphylococcus aureus, Is Anti-infective and Inhibitory for Mupirocin-Resistant Isolates.

Methicillin-resistant Staphylococcus aureus (MRSA) opportunistic infections are a major health burden. Decolonization of hospitalized patients with mupirocin (MUP) has reduced the incidence of infection but has led to MUP resistance. DIBI is a developmental-stage anti-infective agent that sequesters bacterial iron and bolsters innate host iron-withdrawal defenses. Clinical isolates possessing low, high, or no MUP resistance all had similarly high susceptibilities to DIBI. Intranasal DIBI reduced nares bacterial burdens in mice to the same extent as MUP. No resistance was found after exposure to DIBI.

Mixing and matching genes of marine and terrestrial origin in the biosynthesis of the mupirocin antibiotics.

With growing understanding of the underlying pathways of polyketide biosynthesis, along with the continual expansion of the synthetic biology toolkit, it is becoming possible to rationally engineer and fine-tune the polyketide biosynthetic machinery for production of new compounds with improved properties such as stability and/or bioactivity. However, engineering the pathway to the thiomarinol antibiotics has proved challenging. Here we report that genes from a marine Pseudoalternomonas sp. producing thiomarinol can be expressed in functional form in the biosynthesis of the clinically important antibiotic mupirocin from the soil bacterium Pseudomonas fluorescens. It is revealed that both pathways employ the same unusual mechanism of tetrahydropyran (THP) ring formation and the enzymes are cross compatible. Furthermore, the efficiency of downstream processing of 10,11-epoxy versus 10,11-alkenic metabolites are comparable. Optimisation of the fermentation conditions in an engineered strain in which production of pseudomonic acid A (with the 10,11-epoxide) is replaced by substantial titres of the more stable pseudomonic acid C (with a 10,11-alkene) pave the way for its development as a more stable antibiotic with wider applications than mupirocin.

1239. Efficacy of Preoperative Chlorhexidine Gluconate and Mupirocin in the Prevention of Orthopedic Surgical Site Infections

BackgroundSurgical site infections (SSIs) affect 1–5% of patients undergoing surgical procedures in the United States each year and have a mortality rate of up to 75%. We sought to assess the efficacy of a bundled preoperative decolonization treatment protocol to prevent SSIs in hip, knee, or spine procedures.MethodsA retrospective chart review was conducted for 2224 adult patients undergoing spine, knee, or hip procedures performed at the JL Pettis Memorial VAMC from October 1, 2010 to December 31, 2018. NHSN/CDC criteria were utilized. The study included spine surgeries with or without new hardware, but only hip and knee surgeries with new hardware. Procedures with an infection present at the time of surgery (PATOS) were excluded. A pre-operative methicillin-resistant Staphylococcus aureus (MRSA) nares screen was performed. Patients treated were given mupirocin (MPN) to apply to their nares and 4% chlorhexidine gluconate (CHG) to wash all skin prior to the procedure. Patients undergoing emergent procedures received CHG without MPN. The intention to treat model and chi-square test were utilized. The primary endpoints were the infection rates in both the untreated and treated groups. Secondary endpoints included the MRSA screening result, SSI class, causative organism(s), and the surgical site.ResultsA total of 2,112 procedures were included in the study. Thirty-three (1.56%) procedures met NHSN/CDC criteria for SSI. Of the 1,754 (83.0%) procedures given decolonization treatment with MPN and/or CHG, 22 (1.25%) developed an SSI. Of the 358 procedures not receiving treatment, 11 (3.07%) developed an SSI.ConclusionPatients given decolonization treatment had a lower infection rate compared with those who were not treated (1.25% vs. 3.07%, P = 0.0115). Even though the decrease in infection rates were most significant for hip procedures, the overall trend favored the use of a preoperative decolonization treatment protocol for all of the orthopedic procedures studied (Table 1). Current barriers include patient compliance and correct use of decolonization agents, which may affect the actual efficacy of decolonization treatment. A possible confounder was the known increased risk of SSIs in emergent procedures. Disclosures All authors: No reported disclosures.

564. A Five-Year Evolutionary Study of the Minimum Inhibitory Concentrations of Methicillin-resistant Staphylococcus aureus to Mupirocin, Chlorhexidine, and Octenidine in a Singaporean Tertiary Institution

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a common cause of healthcare-associated infection. Eradication of MRSA carriage reduces clinical infection and prevents transmission. In Singapore General Hospital, a series of hospital-wide measures were instituted over three years (Figure 1) to reduce mupirocin (MUP) resistance, and to decrease the bioburden of MRSA colonization amongst inpatients using octenidine (OCT)-based products.MethodsA prevalence study was conducted at three time points (TPs) on consecutive MRSA screening isolates to evaluate for their minimum inhibitory concentrations (MICs) to CHG, OCT and MUP using broth microdilution sensitive plates and the presence of the ileS-2 gene, in 2013 (pre-intervention TP, TP1; n = 160), 2016 (early post-intervention TP, TP2; n = 99) and 2017 (late post-intervention TP, TP3; n = 76). Statistical analyses were performed using the Chi-square test with reference from TP1.ResultsA significant improvement in MUP susceptibility by MIC (256 µg/mL) and ileS-2 testing reduced from 25.0% (TP1) to 12.1% (TP2; P = 0.014) to 5.3% (TP3; P = 0.001) and 30.0% (TP1) to 18.2% (TP2; P = 0.036) to 9.2% (TP3; P = 0.001), respectively. OCT MIC range remained stable at 0.5 to 1 across all three TPs. The number of isolates with reduced CHG susceptibility (MIC ≥4 mg/L) increased over the three TPs from 23.1% to 27.2% (P = 0.45) to 42.1% (P = 0.003), despite decreasing CHG prescription.ConclusionA restrictive MUP usage policy can improve MUP susceptibility amongst MRSA isolates over time. Widespread OCT use did not appear to result in a rise of OCT MIC over the intervention period. Although the clinical significance of reduced susceptibility to CHG remains uncertain, this worrying trend in our institution deserves further studies to better understand mechanisms of CHG resistance. Disclosures All authors: No reported disclosures.

Drug Repurposing Approach for Developing Novel Therapy Against Mupirocin-Resistant Staphylococcus aureus.

Multidrug resistance (MDR) is a major health issue for the treatment of infectious diseases throughout the world. Staphylococcus aureus (S. aureus) is a Gram-positive bacteria, responsible for various local and systemic infections in humans. The continuous and abrupt use of antibiotics against bacteria such as S. aureus results in the development of resistant strains. Presently, mupirocin (MUP) is the drug of choice against S. aureus and MDR (methicillin-resistant). However, S. aureus has acquired resistance against MUP as well due to isoleucyl-tRNA synthetase (IleS) mutation at sites 588 and 631. Thus, the aim of the present study was to discover novel bioactives against MUP-resistant S. aureus using in silico drug repurposing approaches. In silico drug repurposing techniques were used to obtain suitable bioactive lead molecules such as buclizine, tasosartan, emetine, medrysone, and so on. These lead molecules might be able to resolve this issue. These leads were obtained through molecular docking simulation based virtual screening, which could be promising for the treatment of MUP-resistant S. aureus. The findings of the present work need to be validated further through in vitro and in vivo studies for their clinical application.

Bacterial isolates and antimicrobial susceptibility profiles in wound swabs from the Central Polokwane NHLS, in Limpopo Province, South Africa

Bacteria are a major cause of wound infections with associated emergence of drug resistance to commonly used antimicrobials. This situation necessitates proper identification of the wound microbiota and their respective antimicrobial susceptibility profiles. A total of 88 wound swab specimens were collected and cultured by standard microbiological methods. The antibiotic susceptibility test of the bacterial isolates was performed by Kirby-Bauer disk diffusion method. Seven different species of bacteria were isolated. The most common organism isolated was Staphylococcus aureus (29%) followed by Staphylococcus epidermidis (15%), lactose fermenting coliforms (15%), Pseudomonas species (11%), Klebsiella species (7%) as well as Eschericia coli (3%) and Streptococcus group D (3%). Only 1% of Staphylococcus saprophyticus was isolated. All the positive samples were monomicrobial. Fourteen (14) samples showed no growth. The majority of the isolates were resistant to almost all the antimicrobials tested. Streptococcus group D was sensitive to mupirocin and oxacillin while Eschericia coli exhibited sensitivity for colistin sulphate and gentamicin. A high rate of multiple antibiotic resistant isolates was observed in both gram-positive and -negative bacteria. The results are presumptive of the likelihood of a changing resistant profile among the specimen tested. That might be attributable to various factors and warrants further investigation.

Mupirocin Pemphigus-Like Drug Reaction in a Dog

Background: Pharmacodermia is defined as adverse reaction in skin, mucosa and appendages, which generates morpho-functional alterations in cutaneous barrier, inducing autoimmune diseases, such as pemphigus foliaceous, which is known as the most common autoimmune skin disease in dogs. This disease involves autoantibodies against desmoglein and desmocolin molecules, being induced by the use of certain drugs. Mupirocin (pseudomonic acid A) is a broad-spectrum antibiotic with bacteriostatic activity, being effective against Gram-positive pathogens and used to control superficial bacterial folliculitis. Based on that, the aim of this study was to report a pemphigus-like lesions after topical use of mupirocin in dog.Case: An 1-year-old, uncastrated male, Poodle dog, weighing 13.8 kg was treated in a private clinic in Fortaleza. The main complaint was related to pruritus in abdominal and inguinal region, in addition of legs licking. Dermatological examination revealed melanic crusts, epidermal collars and diffuse pustules in inguinal, abdominal, perianal and thoraco-lumbar regions. The therapy was based on topical use of Mupirocin in form of 0.2% aquous spray. After drug administration, the animal presented urticaria, diffuse epidermal collars, papulo-crusted and pustular lesions, which were more evident in abdominal and inguinal region. Nasal erythema, binocular blepharitis, apathy and fever were also observed. Cytological examination and bacterial culture were performed, revealing inflammatory and acantholytic cells and no bacterial growth. Biopsy procedure revealed subcorneal pustule with presence of epithelial acantholytic cells and neutrophils, compatible with canine pemphigus foliaceous. The topical treatment of ocular lesions with 0.1% Tacrolimus associated with systemic treatment with high dose of prednisolone (1.2 mg kg-1). The patient improved the dermatological clinical signs, however, some side effects have already become evident, such as the presence of telangiectasia, polyuria, polyphagia and polydipsia. Heterodox therapy based on the use of azathioprine (2 mg kg-1) was chosen in order to reduce corticoid dose. After 3 days of therapy, blood material was collected for hepatic evaluation, detecting hepatotoxicity. From the results, azathioprine therapy was suspended, and only high-dose corticosteroid therapy (1.5 mg kg-1) was maintained. The patient presented a considerable improvement in the lesion after 10 days of treatment.Discussion: There have been reports that pharmacodermic reactions may be associated with the development of autoimmune diseases, such as pemphigus foliaceus and vulgaris. In some cases, the lesions regress after drug discontination. In others, the medication acts as a triggering factor, activating the genetic predisposition of patient, which develops the pathology even after therapy interruption. The drug related pemphigus-foliaceous is a well-recognized disease in humans, however this disease is limited to sporadic cases in dogs. The therapy was based in use of a high dose of prednisolone, which caused some side effects. Therefore, a heterodox therapy was chosen in order to reduce the corticoid dosage. At the first hemato-biochemical evaluation, the patient already presented significant alterations, being requested to suspend the prescribed treatment, although the owners already reported improvement of the dermatological lesions. Due to this, a higher dose of prednisolone was chosen, obtaining the best response among the therapies used since the beginning of the treatment. After clinical improvement, the gradual reduction of steroidal therapy was started in order to avoid side effects related to suppression of the hypothalamic-pituitary-adrenal axis. This report provides evidences of Mupirocin as a potential triggering factor of pemphigus-like lesions in dogs.

The Influence of Essential Oil Compounds on Antibacterial Activity of Mupirocin-Susceptible and Induced Low-Level Mupirocin-Resistant MRSA Strains.

Because of the bacterial drug resistance development, it is reasonable to investigate chemical compounds capable of preventing the spread of resistance to mupirocin (MUP), commonly used in staphylococcal eradication. The objective of the study was to verify the influence of essential oil compounds (EOCs) on the antibacterial activity of MUP against mupirocin-susceptible (MupS) and induced low-level mupirocin-resistant (MupRL) methicillin-resistant Staphylococcus aureus (MRSA) strains. The following parameters were examined: MRSAMupS and MRSAMupRL susceptibility to EOCs (1,8-cineole, eugenol, carvacrol, linalool, (-)-menthone, linalyl acetate, and trans-anethole), the bacterial cell size distribution, and chemical composition by the use of Fourier Transform Infrared Spectroscopy (FTIR) and Raman spectroscopies. The MRSAMupS and MRSAMupRL strains were susceptible to all tested EOCs. 1,8-cineole and (-)-menthone showed synergistic activity against MRSAMupS in combination with mupirocin, whereas 1,8-cineole exhibited synergistic activity against MRSAMupRL as well. In-depth analysis showed that both MRSAMupS and MRSAMupRL displayed similar distributions of the bacterial cell size. The FTIR and Raman spectra of the MRSAMupS and MRSAMupRL strains showed differences in some regions. New bands in the MRSAMupRL Raman spectrum were observed. It was concluded that the use of 1,8-cineole in combination with mupirocin can increase the mupirocin activity against the MRSAMupS and MRSAMupRL strains.

Mupirocin: applications and production.

Mupirocin is an antibiotic from monocarboxylic acid class used as antibacterial agent against methicillin-resistant Staphylococcus aureus (MRSA) and can be obtained as a mixture of four pseudomonic acids by Pseudomonas fluorescens biosynthesis. Nowadays improving antibiotics occupies an important place in the pharmaceutical industry as more and more resistant microorganisms are developing. Mupirocin is used to control the MRSA outbreaks, for infections of soft tissue or skin and for nasal decolonization. Due to its wide use without prescription, the microorganism's resistance to Mupirocin increased from up to 81%, thus becoming imperative its control or improvement. As the biotechnological production of Mupirocin has not been previously reviewed, in the present paper we summarize some consideration on the biochemical process for the production of pseudomonic acids (submerged fermentation and product recovery). Different strains of Pseudomonas, different culture medium and different conditions for the fermentation were analysed related to the antibiotics yield and the product recovery step is analysed in relation to the final purity. However, many challenges have to be overcome in order to obtain pseudomonic acid new versions with better properties related to antibacterial activity.

General Hospital Patient Antiseptic Decolonization Not Beneficial

Skin and nasal decolonization using chlorhexidine bathing and mupirocin nares application have proven quite effective in reducing drug-resistant

Defining the genes for the final steps in biosynthesis of the complex polyketide antibiotic mupirocin by Pseudomonas fluorescens NCIMB10586

The mupirocin trans-AT polyketide synthase pathway, provides a model system for manipulation of antibiotic biosynthesis. Its final phase involves removal of the tertiary hydroxyl group from pseudomonic acid B, PA-B, producing the fully active PA-A in a complex series of steps. To further clarify requirements for this conversion, we fed extracts containing PA-B to mutants of the producer strain singly deficient in each mup gene. This additionally identified mupM and mupN as required plus the sequence but not enzymic activity of mupL and ruled out need for other mup genes. A plasmid expressing mupLMNOPVCFU + macpE together with a derivative of the producer P. fluorescens strain NCIMB10586 lacking the mup cluster allowed conversion of PA-B to PA-A. MupN converts apo-mAcpE to holo-form while MupM is a mupirocin-resistant isoleucyl tRNA synthase, preventing self-poisoning. Surprisingly, the expression plasmid failed to allow the closely related P. fluorescens strain SBW25 to convert PA-B to PA-A.

Effect of Kangfuxin liquid combined with mupirocin on exit-site granulation tissue hyperplasia in peritoneal dialysis patients

Objective To observe the effect of Kangfuxin liquid combined with mupirocin on exit-site granulation tissue hyperplasia in peritoneal dialysis patients. Methods From January 2012 to December 2017, 35 peritoneal dialysis patients with exit-site granulation tissue hyperplasia in the People's Hospital of Huadu District were selected and randomly assigned into treatment group (15 cases) and control group(20 cases). The control group was given conventional treatment, the treatment group received a sterile dressing moistened with Kangfuxin liquid.Before and after treatment, the exit-site granulation tissue outcome and the incidence of complications were recorded and compared. Results The recovery time of the control group was (8.58±1.36)d, which was longer than (3.43±0.85)d of the treatment group (t=3.57, P<0.05). Exit-site exudation was found in 3 patients of the control group.No complications were observed in the treatment group. Conclusion Kangfuxin liquid combined with mupirocin can shorter the recovery time of exit-site granulation tissue hyperplasia in peritoneal dialysis patients, and reduce the side effect, which is worthy of clinical application. Key words: Peritoneal dialysis; Granulation tissue; Kangfu Xin Ye; Mupirocin

The effect of fennel essential oil and trans-anethole on antibacterial activity of mupirocin against Staphylococcus aureus isolated from asymptomatic carriers.

IntroductionStaphylococcus aureus constitutes the most pathogenic species within the staphylococcal genus. Humans remain the major reservoirs of this pathogen which colonizes mostly anterior nares of healthy individuals.AimTo investigate the effect of fennel essential oil (FEO) and trans-anethole (tA) on antibacterial activity of mupirocin (MUP) against S. aureus strains isolated from asymptomatic carriers.Material and methodsThe content of the FEO was analysed with use of the GC-MS method. The research done on 43 S. aureus isolates with different resistance patterns, obtained from nasal vestibule. Antibacterial activity of MUP in combination with FEO or tA was examined using the agar dilution method and E-test method. The data analysis was done with the Pearson’s χ2 test.ResultsThe chemical composition of FEO was consistent with the European Pharmacopoeia (EP) for the main constituent – tA (77.9%) according to the EP recommendations. Macrolide-lincosamide-streptogramin B resistance phenotype was prevalent among 39.5% of S. aureus isolates. FEO concentrations of 2.0% and 2.5% revealed antibacterial activity against 76.7% of isolates, whereas tA inhibited S. aureus growth at concentrations > 4.0%. The MIC values for MUP combined with FEO as well as for MUP combined with tA were < 0.064 µg/ml for 79.1% and 86.0% of S. aureus isolates, respectively.ConclusionsOur experiment revealed FEO and tA influence on MUP effectiveness. The combination of MUP with FEO as well as MUP with tA are worth considering to implement in S. aureus eradication procedures. These findings will be useful in designing efficient antistaphylococcal agents which can limit the emergence of antibiotic resistance.

Peritoneal Dialysis Access Associated Infections.

Infection is a significant driver of morbidity and mortality in patients with end-stage renal disease undergoing maintenance dialysis. In the United States, septicemia and other infections account for 8% deaths in patients undergoing dialysis. In patients undergoing peritoneal dialysis (PD), PD-related peritonitis remains the most frequent treatment-related infection and is the greatest contributor to infection-related morbidity, including risk for hospitalization, and temporary or permanent transfer to hemodialysis. In the 4 decades since the introduction of ambulatory PD in clinical practice, a large number of treatment innovations have been shown to be effective in reducing the risk for exit site infection and PD-related peritonitis. Notwithstanding the evidence for efficacy of these innovations and the numerous adverse health consequences with PD-related peritonitis, the uptake of these interventions in clinical practice around the world remains inconsistent. This article reviews current knowledge with regards to prevention of PD-associated infections, and the diagnosis and management of exit site infections and peritonitis.

Molecular characteristics and antimicrobial susceptibility to Staphylococcus aureus strains isolated from children with skin and soft tissue infections

Objective To investigate the molecular characteristics, virulence genes and antimicrobial susceptibility to Staphylococcus aureus strains isolated from children with skin and soft tissue infections(SSTIs) in Beijing. Methods A total of 52 Staphylococcus aureus isolates were collected from children with SSTIs in Beijing Children′s Hospital, Capital Medical University, and the clinical data were collected and analyzed.Methicillin-resistant Staphylococcus aureus(MRSA) and methicillin-susceptible Staphylococcus aureus(MSSA) were identified by using the cefoxi-tin disc method and the detection of mecA gene.Multilocus sequence typing (MLST) and staphylococcal protein A(spa) typing were analyzed by the PCR method, and the staphylococcal chromosomal cassette mec (SCCmec) type was analyzed for the MRSA isolates.The pvl, eta, etb, tsst-1 and hlg genes were also detected by PCR.The susceptibility strains to 16 antibiotics were evaluated by using the agar dilution method. Results A total of 52 Staphylococcus aureus SSTIs patients, 30 with MRSA infections and 22 with MSSA infections were included in the study.There were 23 patients (44.2%) less than 1 year old.The most frequent infections were the newborn omphalitis (12/52 strains, 23.1%)and abscess(11/52 strains, 21.2%). ST59-MRSA-SCCmecⅣa-t437 was the most predominant clones of MRSA isolates.Among the MSSA isolates(14/30 strains, 46.7%), no significant epidemic clone was found.Ten sequence types (STs) and 14 spa types were identified in MSSA, and the most common types were ST22(6/22 strains, 27.3%)and t309(5/22 strains, 22.7%), respectively.Notably, the multidrug resistant rates of MRSA and MSSA isolates were all >85%.The percentages of the Staphylococcus aureus SSTIs strains resistant to Erythromycin, Penicillin, Chloramphenicol and Clindamycin were 100.0%, 94.2%, 69.2% and 63.5%, respectively.The tested isolates were susceptible to Trimethoprim/Sulfamethoxazole, Mupirocin, Fusidic acid, Tigecycline, Linezolid and Vancomycin.The pvl gene′s positive rate was 40.4%, and no significant difference between MRSA and MSSA was observed (P>0.05). Eta and etb genes were detected in 2 patients with staphylococcal scalded skin syndrome. Conclusions The Staphylococcus aureus SSTIs strains are most frequently isolated from newborn omphalitis and abscess in Beijing.The multidrug resistant rate is relatively high, so the erythromycin and clindamycin should not be preferred in empiric treatment of children with Staphylococcus aureus SSTIs.The prevalence of pvl gene is 40.1%.ST59-MRSA-SCCmecⅣa-t437 is the common clone of MRSA, while the MSSA isolates have a more diverse genetic background. Key words: Staphylococcus aureus; Skin and soft tissue infections; Molecular characteristics; Virulence; Antimicrobial susceptibility; Child