Biofilm dispersal of community‐associated methicillin‐resistant Staphylococcus aureus on orthopedic implant material

Orthopedic implant‐related bacterial infections are associated with high morbidity that may lead to limb amputation and exert significant financial burden on the healthcare system. Staphylococcus aureus is a dominant cause of these infections, and increased incidence of community‐associated methicillin‐resistant S. aureus (CA‐MRSA) is being reported. The ability of S. aureus to attach to the foreign body surface and develop a biofilm is an important determinant of resistance to antibiotic prophylaxis. To gain insight on CA‐MRSA biofilm properties, USA300 biofilm maturation and dispersal was examined, and these biofilms were found to exhibit pronounced, quorum‐sensing mediated dispersal from a glass surface. For comparison of biofilm maturation on different surface chemistries, USA300 biofilm growth was examined on glass, polycarbonate, and titanium, and minimal differences were apparent in thickness, total biomass, and substratum coverage. Importantly, USA300 biofilms grown on titanium possessed a functional dispersal mechanism, and the dispersed cells regained susceptibility to rifampicin and levofloxacin treatment. The titanium biofilms were also sensitive to proteinase K and DNaseI, suggesting the matrix is composed of proteinaceous material and extracellular DNA. These studies provide new insights on the properties of CA‐MRSA biofilms on implant materials, and indicate that quorum‐sensing dispersion could be an effective therapeutic strategy. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:55–61, 2010     

Effectiveness of a polyhexanide irrigation solution on methicillin‐resistant Staphylococcus aureus biofilms in a porcine wound model

Irrigation and removal of necrotic debris can be beneficial for proper healing. It is becoming increasingly evident that wounds colonized with biofilm forming bacteria, such as Staphylococcus aureus (SA), can be more difficult to eradicate. Here we report our findings of the effects of an irrigation solution containing propyl‐betaine and polyhexanide (PHMB) on methicillin‐resistant Staphylococcus aureus (MRSA) biofilms in a porcine wound model. Thirty‐nine deep partial thickness wounds were created with six wounds assigned to one of six treatment groups: (i) PHMB, (ii) Ringer's solution, (iii) hypochlorous acid/sodium hypochlorite, (iv) sterile water, (v) octenidine dihydrochloride, and (vi) octenilin. Wounds were inoculated with MRSA and covered with a polyurethane dressing for 24 hours to allow biofilm formation. The dressings were then removed and the wounds were irrigated twice daily for 3 days with the appropriate solution. MRSA from four wounds were recovered from each treatment group at 3 days and 6 days hours after initial treatment. Irrigation of wounds with the PHMB solution resulted in 97·85% and 99·64% reductions of MRSA at the respective 3 days and 6 days assessment times when compared to the untreated group. Both of these reductions were statistically significant compared to all other treatment groups (P values <0·05).     

Lugol's solution and Gentian violet eradicate methicillin‐resistant Staphylococcus aureus biofilm in skin wound infections

The study aimed to evaluate the antibacterial efficacy of Lugol''s solution 5% and Gentian violet 1% against methicillin‐resistant Staphylococcus aureus (MRSA) biofilm in vivo. The bactericidal efficacy for treatment of MRSA‐biofilm skin wound infection was tested in a murine model. Luciferase‐tagged S. aureus Xen31, a MRSA‐strain derived from S. aureus ATCC‐3359130, was used for infection. Wounds were made in the skin of mice and infected with MRSA. The mice were treated with Lugol''s solution and Gentian violet. Application of the antimicrobial agents started 24 hours post infection and was repeated daily for five‐days. The antimicrobial effect on the biofilm bacteria was evaluated by measuring bioluminescence from MRSA daily for seven‐days. Lugol''s solution and Gentian violet showed a significant reduction in luminescent signals from the first assessment day to all subsequent days (P < .001). Lugol''s solution and Gentian violet effectively eradicated MRSA in biofilm in vivo and could be alternatives or in addition to topical antibiotics when MRSA‐biofilm wound infection is suspected.     

Methicillin-resistente Staphylococcus aureus (MRSA) – Klinische Implikationen

Zusammenfassung. Die Isolationsrate von MRSA bei Staphylococcus-aureus-Infektionen ist in deutschen Krankenh?usern im Zeitraum 1990 bis 1995 auf 8,7 % angestiegen. Patienten mit chirurgischen Behandlungen und Physiotherapie wiesen ein dreifach erh?htes Risiko für MRSA-Kolonisation bzw. -Infektionen auf. Die h?ufigste durch MRSA verursachte Infektion ist die chirurgische Wundinfektion (28 %). Der Hauptübertragungsweg von MRSA innerhalb eines Krankenhauses ist die Weiterverbreitung des Keims von einem Patienten zum anderen über Kontakt mit den H?nden des behandelnden Personals. Daher ist die entscheidende Strategie zur Vermeidung von übertragungen die Einhaltung einer strikten H?ndehygiene. Bei gleichzeitig nasaler Besiedlung eines Patienten und Infektion an anderer K?rperstelle ist das derzeit verbreitetste Behandlungsregime die lokale Gabe von Mupirocin-Nasensalbe kombiniert mit parenteraler Vancomycin-Therapie. Der nicht indizierte Einsatz von Vancomycin, wie beispielsweise zur perioperativen Prophylaxe oder zur Pr?vention von Katheterinfektionen, sollte vermieden werden, insbesondere nach den kürzlich erschienenen ersten Berichten über das Auftreten Vancomycin-intermedi?r empfindlicher S.-aureus-St?mme (VISA) in Japan und den USA.      

Prostatic abscess caused by community‐acquired methicillin‐resistant Staphylococcus aureus

Prostatic abscess is uncommon and difficult to diagnose, because its clinical presentation mimics lower urinary tract symptoms. Prostatic abscess is often caused by gram‐negative organisms and occasionally by Staphylococcus aureus. Community‐acquired methicillin‐resistant S. aureus (MRSA) often causes skin and soft‐tissue infections, and rarely causes genitourinary infections. We report what we believe is the second case of a prostatic abscess as a result of MRSA in a healthy diabetic patient who was treated with transurethral resection of the prostate and intravenous administration of vancomycin.     

Financial implications of plans to combat methicillin-resistant Staphylococcus aureus (MRSA) in an orthopaedic department

INTRODUCTION

The aim of this study was to calculate retrospectively the cost of MRSA infections in the elective and trauma orthopaedic population in Rotherham District General Hospital in a 3-month period during 2005.

PATIENTS AND METHODS

A total of 686 patients were admitted to the orthopaedic wards and the surgical wounds 10 patients became infected with MRSA.

RESULTS

The cost of these infections when extrapolated over 12 months was £384,000 excluding staff costs.

CONCLUSIONS

The key in the fight against MRSA in the hospital setting is multifactorial and requires a combination of measures. Our solution is: cohort nursing; non-selective screening of all admissions to the orthopaedic wards; use of a polymerase chain reaction as a diagnostic tool; ring-fencing of beds; and separate wound dressing rooms for each ward. The total cost is projected to be £301,000.     

Nosocomial methicillin-resistant Staphylococcus aureus (MRSA) and epidermidis (MRSE) infections in orthopaedic surgery. Importance, prophylaxis and therapy

Summary MRSA/MRSE infections are a major problem in hospitals and although in orthopaedic units the incidence is low awareness of this problem is necessary. Once a MRSA strain has been isolated the strict use of the hygiene precautions has to be applied to avoid epidemic spread of the strain. The patient has to be isolated. The staff has to use gloves and gowns whilst treating the patient. A antimicrobiel hand wash solution has to be used after taking off the gloves and before leaving the isolation room. Patient and staff have to be informed about the pathogenity and the way of infection spread so that infection precaution rules are fulfilled. Antibiotics should only be used in clinically well defined cases and the overall use of antibiotics should be reduced to lower the incidence of MRSA/E isolates. The problems of an MRSA case and its successful treatment are demonstrated.      

Identification and molecular characterization of Staphylococcus aureus and multi‐drug resistant MRSA from monkey faeces in China

Staphylococcus aureus is a commensal bacterium and an important opportunistic pathogen in humans and animals. The increase in multi‐drug resistant (MDR) strains of S. aureus is a growing concern due to their impact on animal health and potential for zoonotic transmission. Increasing evidence has shown that MRSA could be transmitted by faeces. The present study determined the prevalence, antibiotic resistance profile and genotypic characteristics of S. aureus isolated from monkey faecal samples in China. Thirty‐eight out of 145 (26.21%) macaque faecal samples were S. aureus positive, which eight (5.5%) isolates were identified as MRSA. Antimicrobial susceptibility tests showed that most of the S. aureus isolates were resistant to tetracycline (TE, 44.74%), followed by penicillin (P, 21.05%), cefoxitin (FOX, 21.05%) and ciprofloxacin (CIP, 18.42%). The predominant spa types were t13638 (44.74%) and t189 (13.16%), which are reported to be closely associated with human infections in China. All MRSA isolates belonged to the SCCmecV type, which six of MRSA isolates were ST3268, while the other two isolates belonged to ST4981. This study for the first time describes the prevalence of S. aureus and MRSA in monkey faeces in China, indicating that faeces could be a potential factor of transmitting S. aureus between humans and monkeys.     

Linezolid treatment of prosthetic hip infections due to methicillin-resistant Staphylococcus aureus (MRSA)

Prosthetic joint infection is an infrequent but serious complication of total joint arthroplasty. Complete removal of all foreign material is essential, however when prosthesis removal is not possible or is contraindicated, suppressive antibiotic therapy with retention of the functioning hip arthroplasty may be considered. Linezolid, the first approved oxazolidinone, appears to be a promising new agent for the treatment of serious gram-positive infections. We report two cases of prosthetic hip infections with methicillin-resistant Staphylococcus aureus (MRSA) that were successfully treated with long courses of linezolid. This observation suggests that linezolid is a promising drug for the treatment of prosthetic joint infections due to MRSA or other gram-positive bacteria, particularly when other therapeutic approaches are not feasible or a long-term antibiotic therapy is required. Received: 18 May 2001/Accepted: 30 May 2001     

Wirksamkeit alkoholischer Händedesinfektionsmittel gegenüber Methicillin-resistenten Staphylococcus aureus(MRSA)

Zusammenfassung. Zur Bestimmung der Wirksamkeit alkoholischer H?ndedesinfektionsmittel gegenüber 3 MRSA-St?mmen im Vergleich zu 3 Methicillin-empfindlichen Staphylococcus aureus -St?mmen (MSSA) wurden 1-Propanol (60 %) sowie Sterillium^? und Spitaderm^? in verschiedenen Verdünnungen und bei verschiedenen Einwirkzeiten (15 s, 30 s und 60 s) im quantitativen Suspensionsversuch untersucht. In der Anwendungskonzentration war nach 30 s für alle Pr?parate eine Keimreduktion von mehr als 6 log₁₀-Stufen gegenüber MRSA und MSSA nachweisbar. In Verdünnung (50 %) und bei kürzerer Einwirkzeit (15 s) wiesen alle Pr?parate signifikant niedrigere Reduktionsfaktoren gegenüber MRSA auf (p < 0,05). Verdünntes Sterillium^? (50 %) erreichte weder gegenüber MRSA noch gegenüber MSSA nach 30 s eine Keimreduktion von mehr als 5 log₁₀-Stufen. Die Bedeutung einer sachgerechten Durchführung der H?ndedesinfektion zur Unterbrechung von Infektketten mit MRSA wird deutlich.      

Vancomycin-Impregnated polymethylmethacrylate beads for methicillin-resistant Staphylococcus aureus (MRSA) infection: Report of two cases

Two patients with methicillin-resistant Staphylococcus aureus (MRSA) infection were treated with vancomycin (VCM)-impregnated polymethylmethacrylate (PMMA) beads. One patient, who had a history of polycystic kidney and diabetes mellitus, who was receiving hemodialysis due because of non-functional kidney, underwent resection of an intermediate grade chondrosarcoma in the pelvis. MRSA infection developed and curettage of the lesion was performed, but MRSA infection recurred. During the second revision surgery, VCM-impregnated PMMA beads were implanted. MRSA infection has not recurred for 16 months since the implantation of the VCM beads. The second patient had a history of total hip arthroplasty (THA) performed because of coxarthrosis. After the initial surgery, MRSA infection developed, recurring after the second revision surgery for THA. After curettage following removal of the prosthesis, VCM beads were implanted with a spacer composed of VCM-PMMA and a Luque rod. Infection did not recur and THA revision was performed 3 months after the VCM beads implantation. Fifteen months after the last revision surgery, infection has not recurred. Received for publication on July 24, 1997; accepted on Jan. 13, 1998     

Colonisation with methicillin‐resistant Staphylococcus aureus prior to renal transplantation is associated with long‐term renal allograft failure

Renal transplant recipients are at an increased risk of developing Methicillin‐resistant Staphylococcus aureus due to their immunosuppressed status. Herein, we investigate the incidence of MRSA infection in patients undergoing renal transplantation and determine the effect of MRSA colonisation on renal allograft function and overall mortality. Between January 1st 2007 and December 31st 2012, 1499 consecutive kidney transplants performed in our transplant unit and a retrospective 1:2 matched case‐control study was performed on this patient cohort. The 1‐, 3‐ and 5‐year overall graft survival rates were 100%, 86% and 78%, respectively, in MRSA positive recipients compared with 100%, 100% and 93%, respectively, in the control group (P < 0.05). The 1‐, 3‐ and 5‐year overall patient survival rates were 100%, 97% and 79%, respectively, in MRSA positive recipients compared with 100%, 100% and 95%, respectively, in the control group (P = 0.1). In a multiple logistic regression analysis, colonisation with MRSA pre‐operatively was an independent predictor for renal allograft failure at 5 years (hazard ratio: 4.6, 95% confidence interval: 1–30.7, P = 0.048). These findings demonstrate that the incidence of long‐term renal allograft failure is significantly greater in this patient cohort compared with a matched control population.     

Infection-free surgery: how to improve hand-hygiene compliance and eradicate methicillin-resistant Staphylococcus aureus from surgical wards

INTRODUCTION

Healthcare-associated infections cost the UK National Health Service £1 billion per annum. Poor hand hygiene is the main route of transmission for methicillin-resistant Staphylococcus aureus (MRSA), leading to increased mortality and morbidity for infected patients. This study aims to quantify MRSA infection rates and compliance of alcohol gel application at the entrance to a surgical ward and assess how a simple intervention affects compliance.

SUBJECTS AND METHODS

Compliance was assessed via a discretely positioned close-surveillance camera at the ward entrance, ootage was reviewed to monitor compliance of all persons entering the ward over a 12-month period.

RESULTS

For the initial 6 months, mean alcohol gel compliance was 24% for all persons entering the ward. After this period, a conspicuous strip of bright red tape was positioned along the corridor approaching the ward entrance. The red line continued up the wall to an arrow head pointing to the two alcohol gel dispensers on the wall. Mean compliance over the subsequent 6 months significantly improved to 62% (P< 0.0001). Compliance improved for all persons entering the ward as follows (before – after, significance): doctors (0% – 54%, P< 0.01); nurses (24% – 75%, P< 0.05); porters (21% – 67%, P< 0.05); visitors (35% – 68%, P< 0.01); patients (23% – 44%, P > 0.05). There were two cases of MRSA bacteraemia in the initial 6 months and no cases in the following 6 months with the red line in situ.

CONCLUSIONS

This study demonstrates how a simple intervention significantly improves hand-hygiene compliance with associated eradication of MRSA.     

A study of resistance to antiseptics of methicillin resistant Staphylococcus aureus (MRSA) in gastroenterological surgery

Highly methicillin-resistant Staphylococcus aureus (H-MRSA, MIC greater than 100 micrograms/ml) was prevalent from 1986 in our institution. The failure of povidone-iodine to reduce the prevalence of MRSA led us to choose chlorhexidine-ethanol solution as an antiseptic, and then the isolation frequency of H-MRSA decreased significantly in 1988. When H-MRSA began to increase again recently, we studied the resistance to antiseptics of MRSA in order to investigate the cause of this re-increase. Common antiseptics were tested against 45 strains of H-MRSA and 22 strains of methicillin sensitive S. aureus (MSSA, MIC less than 12.5 micrograms/ml). Dilute preparations (1:100) of povidone-iodine and chlorhexidine-ethanol solution were more effective on H-MRSA than the other antiseptics. Though there was no significant difference between H-MRSA and MSSA in their sensitivity to povidone-iodine, the killing of H-MRSA strains was more delayed than the killing of MSSA strains in chlorhexidine. Even after a 120-second exposure, 13.3% of H-MRSA strains were resistant to chlorhexidine (more than 1000 colonies were recovered). These highly chlorhexidine-resistant strains have been isolated since 1987 when we chose chlorhexidine-ethanol solution as the antiseptic in our institution. Therefore we suspect that the acquirement of resistance to antiseptics by H-MRSA caused the re-increase of this strain.