Nasal Carriage of Methicillin-Resistant Staphylococcus aureus in Vascular Surgery

The purpose of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and to define risk factors allowing identification of high-risk patients for MRSA nasal carriage at admission to the vascular surgery unit. From March 23, 2004 to July 13, 2004, screening for nasal carriage of MRSA was conducted at admission to the vascular surgery unit and 1 week thereafter. To analyze risk factors for MRSA nasal carriage at admission to the vascular surgery unit, a case-control study was carried out in patients presenting colonization at the time of admission. A total of 308 patients underwent nasal screening for MRSA. Thirteen were colonized with MRSA (nine at admission and four acquired), i.e., 4.2% of patients. Methicillin-susceptible Staphylococcus aureus (MSSA) was found in 11.4% of patients who underwent screening. Six patients with MRSA infection were identified during the study period. The two patients who acquired infection were colonized at the time of admission. Arrival from another health-care facility and from another department was a significant risk factor for carriage of MRSA. The prevalence of nasal carriage in vascular surgery was 4.2%. Nasal screening is highly cost-effective since 60% of MRSA carriers were undetected using diagnostic specimens alone. French recommendations issued for cardiac and orthopedic surgery by the consensus conference on preoperative management of infectious risk on March 5, 2004, should be extended to vascular surgery.     

Risk factors for Staphylococcus aureus infection in liver transplant recipients.

Staphylococcus aureus is the leading cause of bacterial infection in liver transplant recipients. Preoperative nasal carriage of methicillin-resistant S. aureus (MRSA) is associated with a high risk of infection. We conducted a retrospective cohort study in order to identify independent risk factors for early-onset S. aureus infection after liver transplantation. Patients were screened preoperatively for methicillin-susceptible S. aureus (MSSA) and MRSA nasal carriage. Risk factor analysis was performed by univariate analysis followed by stepwise logistic regression. Of the 323 patients included, 63 (19.5%) patients developed S. aureus infection (36 MRSA, 27 MSSA) within 1 month of surgery. Variables significantly associated with infection in the univariate analysis were MRSA and MSSA nasal carriage, alcoholic cirrhosis, absence of hepatocellular carcinoma, decreased prothrombin ratio, and presence of ascites. In the multivariate analysis, MRSA carriage (odds ratio [OR]: 20.9, P < 0.0001), MSSA carriage (OR: 3.4, P = 0.0004), alcoholic cirrhosis (OR: 2.4, P = 0.01) and decreased prothrombin ratio (OR: 1.2, P = 0.01) were independent predictors of infection. Molecular typing showed that the infecting isolate was identical to the isolate from the nose in most patients. In conclusion, preoperative nasal carriage of MRSA and MSSA is an independent risk factor for S. aureus infection in liver transplant recipients. The infection is most often of endogenous origin. Alcoholic cirrhosis and the severity of liver failure are also associated with a high risk of infection.     

Impact of new methicillin-resistant Staphylococcus aureus carriage postoperatively after living donor liver transplantation

BACKGROUND: Preoperative carriage of methicillin-resistant Staphylococcus aureus (MRSA) is associated with an increased risk of MRSA infection after liver transplantation. It is not known, however, whether new MRSA carriage postoperatively also increases the risk of MRSA infection after liver transplantation. METHODS: We retrospectively reviewed the data from 242 adult patients who underwent living donor liver transplantation (LDLT) including microbiological and medical records from admission to 3 months after LDLT. Uni and multivariate analyses were performed to identify independent risk factors for postoperative MRSA infection among preoperative noncarriers of MRSA. RESULTS: Postoperative MRSA infection occurred in 18 of 219 preoperative noncarriers of MRSA by median postoperative day 26. Operation time of at least 16 hours and postoperative colonization with MRSA independently predicted postoperative MRSA infection. CONCLUSION: Postoperative surveillance cultures should be performed periodically after liver transplantation to identify high-risk candidates for postoperative MRSA infection, even among preoperative noncarriers of MRSA.     

Methicillin-resistant Staphylococcus aureus carriage, infection and transmission in dialysis patients, healthcare workers and their family members.

BACKGROUND: Carriage and subsequent infection with methicillin resistant S. aureus (MRSA) and its transmission between hospital and community settings have not been studied in dialysis patients and their contacts. METHODS: Surveillance for nasal MRSA carriage and infection among dialysis patients, healthcare workers (HCWs) and their family members in a dialysis centre was prospectively undertaken during three time periods within 1 year. Molecular typing was used to determine epidemiological relationship. RESULTS: Among 1687 samples collected, MRSA colonization rates were 2.41% (2/83) for peritoneal dialysis patients and 2.36% (12/509) for haemodialysis patients. Five (5/14) subjects subsequently had MRSA infection. The clinical MRSA isolates had the same molecular type as the colonized strains of the same person, indicating MRSA colonization preceded clinical infection. Significantly higher MRSA nasal carriage rates were observed among family members of HCWs than family members of dialysis patients (P = 0.0024). Only three major clones were observed. Pulmonary diseases (OR: 4.873, 95% CI: 1.668-14.235), recent admission to a hospital (OR: 2.797, 95% CI: 1.291-6.059) and recent antibiotics usage (OR: 2.319, 95% CI: 1.053-5.104) were also significantly associated with MRSA carriage. CONCLUSION: Transmission of MRSA among dialysis patients, HCWs and their family members in a dialysis unit could be inferred. Monitoring and eradication of MRSA from patients, HCWs and their family members should be considered to prevent continuous spread between healthcare facilities and the community.     

Colonization by methicillin-resistant Staphylococcus aureus is a predictive factor for the resistance phenotype of an infectious strain of S. aureus

OBJECTIVE: To assess the predictive value of a previous colonization with methicillin-resistant Staphylococcus aureus for the resistance pattern of a bacteriological specimen significantly positive to S. aureus. STUDY DESIGN: Retrospective study of patients' files. PATIENTS: Patients admitted for at least 48 hours in a surgical intensive care unit from April 1, 1996 to December 31, 1997. METHODS: Collection of patients' characteristics and chronology of positive microbiological specimens with methicillin-susceptible (MSSA) or -resistant (MRSA) S. aureus from medical and laboratory records. During the study period, screening for nasal or perineal colonization with MRSA was systematically performed on admission and weekly thereafter. RESULTS: The files of 540 patients were reviewed. MSSA and MRSA infections occurred in 7% (39/540) and 4% (20/540) of the patients respectively. By opposition with MSSA infections, MRSA infections occurred more frequently in patients previously colonized with MRSA (13 infections in 63 colonized patients [21%] versus 7 infections in 477 non-colonized patients [2%], odds ratio = 18, confidence interval: 6-51, P < 0.0001). The median delay between colonization and infection was 5 days. The positive and negative predictive values for previous colonization with MRSA to predict infection with MRSA in presence of a bacteriological specimen significantly positive with S. aureus were 81 and 84%, respectively. CONCLUSION: The probabilistic use of a glycopeptide in presence of a bacteriological specimen significantly positive with S. aureus should be limited to patients already colonized with MRSA, in order to decrease the abusive administration of these antibiotics.     

Importance of methicillin-resistant Staphylococcus aureus eradication in carriers to prevent postoperative methicillin-resistant Staphylococcus aureus surgical site infection

Although infrequent, postoperative methicillin-resistant Staphylococcus aureus (MRSA) surgical site infection (SSI) is associated with significant morbidity and cost. Previous studies have identified the importance of MRSA screening to diminish the risk of postoperative MRSA SSI. The current study quantifies the importance of eradication of the MRSA carrier state to prevent MRSA SSI. Beginning February 2007, all admissions to an 800-bed tertiary care hospital were screened for MRSA by nasal swab using rapid polymerase chain reaction-based testing. Patients found to be nasal carriers of MRSA were treated with 2 per cent mupirocin nasal ointment and 4 per cent chlorhexidine soap before surgery. The subset of patients undergoing procedures that are part of the Surgical Care Improvement Project (SCIP) were followed for MRSA SSI (n = 8980). The results of preoperative MRSA screening and eradication of the carrier state were analyzed. Since the initiation of universal MRSA screening, 11 patients undergoing SCIP procedures have developed MRSA SSI (0.12%). Of these, six patients (55%) had negative preoperative screens. Of the five patients with positive preoperative screens, only one received treatment to eradicate the carrier state. In patients who develop MRSA SSI, failure to treat the carrier state before surgery results in MRSA SSI.     

The preventive effects of mupirocin against nasotracheal intubation-related bacterial carriage

Nasotracheal intubation is often required during dental and maxillofacial surgery. The complications of nasotracheal intubation are well documented, but there have been few systematic attempts to find methods for their prevention. We examined intubation-related carriage of bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), into the trachea and evaluated the effects of topical nasal treatment with mupirocin on intubation-related bacterial colonization. Of 38 patients without mupirocin treatment (nontreatment group), 27 (71.1%) showed general bacterial colonization in the nasal cavities before intubation. MRSA was isolated from 13.2% of the patients in this group. However, 10 of 22 patients (45%) treated with mupirocin (treatment group) showed colonization by general bacteria, and 2 (9%) were MRSA carriers before intubation. After nasal intubation, general bacteria and MRSA were isolated from the endotracheal tube tip in 66.2% and 16.7% of these patients in the nontreatment group, respectively. In contrast, general bacteria were isolated from the endotracheal tube tip in 19.2% of these patients after oral intubation, but no MRSA was detected. However, after nasal intubation, general bacteria were isolated from the endotracheal tube tip in 3 of the patients in the treatment group (23.1%), and no MRSA was detected, whereas no bacteria were isolated from oral intubation tubes. These results indicate that bacteria were carried into the trachea at a more frequent rate by nasal intubation as compared with oral intubation, and nasal treatment with mupirocin eliminated the nasal carriage of S. aureus. Topical nasal treatment with mupirocin before nasal intubation is thus suggested to be effective for preventing carriage of bacteria into the trachea. IMPLICATIONS: We studied the carriage rate of bacteria into the trachea caused by nasal intubation. The bacterial carriage by nasal intubation was more frequent than that by oral intubation, and intranasal administration of mupirocin eliminated the carriage of S. aureus. These results indicate that topical nasal treatment with mupirocin is effective to prevent carriage of bacteria into the trachea.     

Nasal colonization of Staphylococcus aureus and the risk of surgical site infection after spine surgery: a meta-analysis

BACKGROUND CONTEXTNasal colonization of Staphylococcus aureus may increase the risk of surgical site infection (SSI) after spine surgeries, although the results of previous studies were inconsistent.PURPOSETo evaluate the influences of nasal colonization of S. aureus, methicillin-susceptible SA, and methicillin-resistant SA (MRSA) on the incidence of SSI after spine surgery.STUDY DESIGN/SETTINGSystematic review and meta-analysis.PATIENT SAMPLESeven studies including 10,650 patients who underwent nasal swab examination before spine surgeries were included, and 221 patients had nasal colonization of MRSA at baseline.OUTCOME MEASURESAssociation between baseline nasal colonization of S. aureus, MRSA, and SSI after spine surgery.METHODSRelevant follow-up studies were identified through systematic searches of the PubMed, Embase, and Cochrane Library databases. A random effects model was applied to pool the results. Subgroup analyses were performed according to whether MRSA decolonization was applied.RESULTSDuring follow-up, a total of 244 SSI events occurred, including 57 MRSA-SSI events. Pooled results showed that nasal S. aureus (risk ratio [RR]=0.75, p=.22) or methicillin-susceptible SA colonization (RR=0.60, p=.22) did not significantly affect the risk of overall SSI after surgeries. However, nasal MRSA colonization was associated with significantly increased risks of overall SSI and MRSA-SSI (RR=2.52 and 6.21, respectively, both p<.001). Interestingly, the associations between nasal MRSA colonization and increased risks of overall and MRSA-SSI remained significant in studies without MRSA decolonization, but became insignificant in studies with MRSA decolonization.CONCLUSIONSNasal MRSA colonization may be associated with increased risks of overall SSI and MRSA-SSI after spine surgeries, and nasal MRSA decolonization may be associated with a reduction of SSI in these patients.     

Nasal Methicillin-Resistant S. Aureus is a Major Risk for Mediastinitis in Pediatric Cardiac Surgery

Background: Mediastinitis caused by methicillin-resistant Staphylococcus aureus (MRSA) is a serious complication after pediatric cardiac surgery. An outbreak of surgical site infections (SSIs) provided the motivation to implement SSI prevention measures in our institution.Methods: Subjects comprised 174 pediatric patients who underwent open-heart surgery after undergoing preoperative nasal culture screening. The incidence of SSIs and mediastinitis was compared between an early group, who underwent surgery before SSI measures (Group E, n = 73), and a recent group, who underwent surgery after these measures (Group R, n = 101), and factors contributing to the occurrence of mediastinitis were investigated.Results: The incidence of both SSIs and Mediastinitis has significantly decreased after SSI measures. With regard to factors that significantly affected mediastinitis, preoperative factors were “duration of preoperative hospitalization” and “preoperative MRSA colonization,” intraoperative factors were “Aristotle basic complexity score,” “operation time,” “cardiopulmonary bypass circuit volume” and “lowest rectal temperature.” And postoperative factor was “blood transfusion volume.” Patients whose preoperative nasal cultures were MRSA-positive suggested higher risk of MRSA mediastinitis.Conclusions: SSI prevention measures significantly reduced the occurrence of SSIs and mediastinitis. Preoperative MRSA colonization should be a serious risk factor for mediastinitis following pediatric cardiac surgeries.     

Outcomes of Colonization with MRSA and VRE Among Liver Transplant Candidates and Recipients

Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE) infections cause significant morbidity and mortality among liver transplant candidates and recipients. To assess rates of MRSA and VRE colonization, we obtained active surveillance cultures from 706 liver transplant candidates and recipients within 24 h of admission to an 11-bed liver transplant ICU from October 2000 to December 2005. Patients were followed prospectively to determine the cumulative risk of MRSA or VRE infection or death by colonization status. Outcomes were assessed by Kaplan–Meier survival analysis and Cox regression and multivariate logistic regression adjusting for covariates. The prevalence of newly detected MRSA nasal and VRE rectal colonization was 6.7% and 14.6%, respectively. Liver transplant candidates and recipients with MRSA colonization had an increased risk of MRSA infection (adjusted OR = 15.64, 95% CI 6.63–36.89) but not of death (adjusted OR = 1.00, 95% CI 0.43–2.30), whereas those with VRE colonization had an increased risk both of VRE infection (adjusted OR = 3.61, 95% CI 2.01–6.47) and of death (adjusted OR = 2.12, 95% CI 1.27–3.54) compared with noncolonized patients. Prevention and control strategies, including use of active surveillance cultures, should be implemented to reduce the rates of both MRSA and VRE colonization in this high-risk patient population.     

The impact of nasal carriage of methicillin-resistant and methicillin-susceptible Staphylococcus a ureus (MRSA & MSSA) on vascular access-related septicemia among patients with type-II diabetes on dialysis

BACKGROUND: Fairly higher nasal carriage rates among type-II diabetics place them at a greater risk of endogenous Staphylococcus aureus linked vascular access-related septicemia (VRS) that is also dependent on the type of vascular access used for hemodialysis (HD). The prevalence of nasal carriage of methicillin susceptible and methicillin-resistant S. aureus (MSSA and MRSA) and its impact on VRS was determined in order to identify most vulnerable group and plan potential prophylactic strategies, accordingly. METHODS: Five standardized nasal swab cultures were performed in 208 patients enrolled for long-term HD through July 1996 to July 1999. Persistent nasal carriage was defined by two or more positive cultures for MSSA or MRSA. Peripheral blood cultures were collected on clinical suspicion of septicemia. RESULTS: The prevalence of type-II diabetes of 28.0% with 72.4% of nasal carriage rate and three folds higher S. aureus related VRS (RR-3.19, p<0.0001) than diabetic non-carriers on HD, was observed. Type-II diabetics also had higher MSSA and MRSA nasal carriage rates (53.4% and 19.0%) than non-diabetic nasal carriers (18.6 and 6.0%) yet, carried a comparable (RR-4.0 vs. 4.5) risk of VRS between MSSA and MRSA nasal carriers. Among diabetic type-II S. aureus nasal carriers, central venous catheters (CVCs) carried 35 and 38 times higher collective risk of developing MSSA and MRSA nasal carriage-related VRS respectively than Arterio-venous fistula (AVF). The AVF recorded the lowest risk of developing MSSA and MRSA nasal carriage-related VRS (0.013 and 0.010 episodes/patient-year) in both diabetic type-II MSSA and MRSA nasal carrier groups. CONCLUSIONS: Diabetic type-II S. aureus nasal carriers on HD through CVCs make an extremely high-risk group for MSSA and MRSA nasal carriage-related VRS. The incidence of S. aureus nasal carriage-related VRS could reasonably be reduced through a challenging obligation of optimizing AVF prevalence in this high-risk group, while limiting the use of CVCs, at the same time.     

Endonasal mupirocin in the prevention of nosocomial pneumonia

BACKGROUND: To evaluate efficacy of mupirocin ointment nasal application in prevention of MRSA ventilatory associated pneumonia (VAP). METHODS: Design: prospective, double-blind, randomized, clinical trial. PATIENTS: 48 consecutive intubated patients admitted in the Intensive Care Unit during a three month period. SETTING: University of Florence; Intensive Care. INTERVENTIONS: Randomized application of 2 ml of Mupirocin ointment three times a day for three days (Group A; n = 24) or placebo (Group B n = 24). STATISTIC: Chi 2 or Fisher exact test. MEASUREMENTS: Bacteriologic evaluation of nasal carriage at admission in ICU, and after 3 days of prevention; evaluation of bacteriology of bronchial aspirate in the case of symptoms of ventilatory associated pneumonia. RESULTS AND CONCLUSIONS: Relative risk of nasal carriage by pathological bacterial strains is 7.2 times in hospitalized patients more than in home patients (18/25 vs 7/23); MRSA nasal carriage is present at admission on 20% of hospitalized patients. Nasal carriage of Staphylococcus strains is reduced of 90% by Mupirocin application but is reduced only of 50% by placebo application (p < 0.05). In Group B, VAP occurred in 5 patients vs 3 of Group A; the more frequent incidence of VAP in group B is due to MRSA infection (p < 0.01) and it is related to MRSA nasal carriage.     

<Emphasis Type="Italic">Staphylococcus aureus</Emphasis> Nasal Colonization in Preoperative Orthopaedic Outpatients

Nasal colonization with Staphylococcus aureus (SA) increases the risk of surgical site infection (SSI). We first (1) determined the prevalence of asymptomatic nasal colonization with SA, (2) assessed trends in methicillin resistance with time, (3) ascertained risk factors for nasal colonization; and (4) correlated SSI to nasal colonization status and procedure. We performed a cross-sectional analysis of SA nasal colonization among healthy preoperative orthopaedic outpatients between 2003–2005 who were within 2 weeks of surgery. Of 284 patients, 86 (30%) carried SA; of these, 81 (94%) were colonized with methicillin-sensitive and five (6%) with methicillin-resistant SA (MRSA). Total SA colonization increased from 25/78 (32%) in 2003 to 37/97 (38%) in 2005, and colonization with MRSA increased from 0/78 (0%) to four of 97 (4%), respectively. We found no associations between nasal carriage and demographics or procedures. Surgical site infection occurred in nine of 282 (3%), four of which were attributable to SA; these included 0/43 (0%) carriers who received decolonization with 2% mupirocin, two of 43 (4.7%) who declined decolonization, and two of 196 (1.0%) who were noncarriers. Nasal colonization with SA, including MRSA, among preoperative orthopaedic outpatients is increasing and their rates reflect community rates. Knowledge of colonization status may be important in decolonization, choosing perioperative or any subsequent empiric antibiotics. One of the authors (CSP) has received funding from GlaxoSmithKline Pharmaceuticals.     

Correlation between nutritional status and Staphylococcus colonization in hip and knee replacement patients

Orthopaedic patients with poor nutritional status are at an increased risk of postoperative complications, such as infection and wound healing. Nasal colonization with Staphylococcus aureus, especially with methicillin-resistant Staphylococcus aureus, has been shown to be a risk factor for surgical-site infections. We examined the incidence of nutritional depletion in our arthroplasty population and its correlation with Staphylococcus aureus colonization. We conducted a retrospective review of prospectively collected data of our arthroplasty patient population. Patients with known Staphylococcus aureus colonization or surgical-site infection were compared with a random cohort of patients. Patient demographics, preoperative nasal culture, and two nutritional screening scores were collected. Six hundred and fifty-two patients underwent arthroplasty and completed preoperative nasal cultures and nutritional assessment. A high percentage (27%) of our patients demonstrated some level of nutritional depletion prior to joint replacement. Overall nutritional scores were not significantly associated with surgery-type, preoperative nasal culture, or surgical- site infection in our patient population.     

The relation between positive screening results and MRSA infections in burn patients

IntroductionMethicillin-resistant Staphylococcus aureus (MRSA) is a key pathogen in burn patients. Several factors put them at increased risk of MRSA infection: partial loss of the skin barrier, the immune-compromising effects of burns, prolonged hospital stays, and invasive procedures. This study aims to find the relation between MRSA screening swab cultures taken within 48 h of admission, weekly surveillance cultures, and MRSA infection secondary to colonization.MethodsThe data of all burns patients admitted to the referral centre for burns from 2012 to 2016 were reviewed. MRSA cultures taken at admission and on weekly surveillance screening, including nasal, perianal, and wound swabs, were reviewed. To determine associations between MRSA colonization and infection rates, both MRSA-positive and MRSA-negative swab cultures were included in the analysis. Several risk factors were considered: age, gender, ethnicity, %TBSA, BAUX index, inhalational injury, ICU admission and days, need for ventilator support and days, length of stay (LOS) in hospital, and complications. Univariate and multiple logistic regression analyses were used to predict correlations between positive swab cultures and risk factors.ResultsData from 396 patients were reviewed. The median age at admission for the burn patients was 46 (IQR: 31–59) years. On admission, 2.5% of patients were MRSA positive, whereas 17.9% were found to be MRSA positive on weekly surveillance screening. At surveillance, 60.6% developed an infection secondary to MRSA colonization. An MRSA infection was not identified for any patient who did not have at least one positive admission or surveillance swab. A statistically significant association was found between any positive swab and MRSA infection (P < 0.001).The median number of complications reported in the MRSA-positive group was 2 (IQR: 1–3) versus 0 (IQR: 0–1) in the MRSA-negative group and the median length of hospital stay in the MRSA-positive group was 34.5 (IQR: 20.25–56.25) days versus 7 (IQR: 3–16) days in the MRSA-negative group (P < 0.001).ConclusionNosocomial MRSA colonization rates are high, and patients incurring infections experience a greater than average LOS in hospital and complications. Over 60% of patients who had a positive swab culture at surveillance developed an infection, whereas, no patient with a negative MRSA swab status developed an infection. Hence, pragmatic prevention strategies have to be implemented.     

Prediction of surgical site infection in spine surgery from tests of nasal MRSA colonization and drain tip culture

Purpose

MRSA is an organism that is a possible risk factor for postoperative SSI. The purpose of the study was to examine relationships among surgical site infection (SSI) after spinal surgery, nasal methicillin-resistant staphylococcus aureus (MRSA) colonization, and wound drain culture results.

Methods

The subjects were 132 patients who underwent spinal instrumentation surgery. A preoperative nasal swab was used to check for the presence of MRSA colonization, and a wound drain tip culture was performed for detection of SSI. Data from culture studies using nasal samples and those from the distal tip of the wound drain were used for analysis.

Results

Five patients (3.8%) had nasal MRSA, 17 (13%) had positive drain tip cultures, 15 (11%) had SSIs, and 10 (8%) had SSIs with MRSA. Patients with nasal MRSA had a higher rate of detection of bacteria in the drain tip culture (40 vs. 19%, p = 0.065), and the SSI rate was significantly higher in patients with a positive drain tip culture (33 vs. 10%, p = 0.012). The total SSI rate differed significantly between patients with and without nasal MRSA (40 vs. 10%, p = 0.039); however, the SSI with MRSA rate did not differ significantly between these groups.

Conclusion

MRSA carriers were not necessarily associated with MRSA infection, but were related to a positive drain tip culture and SSI, which might be due to endogenous skin bacteria. Therefore, possible SSI should be considered in patients with nasal MRSA colonization or bacteria detected in a drain tip culture.

     

Influence of methicillin-resistant Staphylococcus aureus carrier status in liver transplant recipients

The prevalence of methicillin-resistant Staphylococus aureus (MRSA) has increased worldwide and MRSA has emerged as an important cause of sepsis in cirrhotic patients and liver transplant recipients. In this retrospective study, the prevalence of MRSA colonization and its influence on infections following orthotopic liver transplantation (OLT) was investigated. From August, 2002 until November, 2004, 66 primary cadaver OLT were performed for adult recipients. Antibody induction used Daclizumab (n = 49) or ATG (n = 14). Maintenance immunosuppression consisted of tacrolimus and steroids, with 30 patients receiving mycophenolate mofetil and 4, rapamune. For perioperative anti-infectious prophylaxis cefotaxime, metronidazole, and tobramycin were administered for 48 hours. The preoperatively performed routine swabs revealed MRSA colonization in 12 of 66 (18.2%) patients. The stage of cirrhosis was equivalent for MRSA(-) patients according to Child score. The mean MELD score was significantly higher for MRSA(+) patients (24.3 versus 18.7, P = .036). More MRSA(+) patients were hospitalized at the time of transplantation (14/54 versus 8/12, P = .018). The incidence of posttransplant infections was not significantly different among the two groups. Within the first year 7 of 66 (10.6%) patients died: 3 of 12 (25%) MRSA(+) and 4 of 54 (7.4%) MRSA(-). The 1-year survival was lower in the MRSA(+) group (74.1% versus 94.1%). In conclusion, this study did not show that an MRSA-positive carrier status implies an increased risk for septic complications following OLT. Mortality was increased for MRSA(+), but failed to show a significant difference. A significantly higher MELD score and pretransplant hospitalization for MRSA(+) patients may contribute to the higher mortality and reflect sicker patients.     

Effect of rifampin onStaphylococcus aureus colonization in children on chronic peritoneal dialysis

The efficacy of rifampin in eliminatingStaphylococcus aureus colonization was evaluated in a pediatric peritoneal dialysis population. Six children with documented nasal colonization were treated for 7 days with rifampin and cloxacillin. Although antimicrobial therapy eliminated nasal carriage in all patients, recolonization occurred in 66%. Exit site colonization proved difficult to eradicate with negative cultures documented in only 3 of 5 children after rifampin/cloxacillin therapy. AlthoughS. aureus carriage is a risk factor forS. aureus infections, efforts to eradicate carriage with rifampin are hindered by rapid recolonization.     

Low Prevalence of Colonization with Vancomycin-Resistant Enterococcus in Patients Awaiting Liver Transplantation

The orthotopic liver transplant (OLT) population has been particularly affected by the increase in vancomycin-resistant enterococcus (VRE) infections in recent years. Pre-transplant colonization prevalence, the role of spontaneous bacterial peritonitis (SBP) antimicrobial prophylaxis as a risk factor, and the risk of post-OLT infection in colonized patients are all unknowns. We prospectively evaluated OLT candidates at our center with the aim of answering these questions. Vancomycin-resistant enterococcus colonization status was determined by rectal culture. Data collected included illness severity, antibiotic use (including SBP prophylaxis), waiting time, previous hospitalizations, and invasive procedures. Eighty-eight patients (31 female, 57 male, median age 52 years) were enrolled. The most common diagnoses were hepatitis C (49%), primary sclerosing cholangitis (13.6%), and alcoholic liver disease. Median MELD score was 11.5 (range 7-24), and median waiting time was 551 days (range 1-2224). Vancomycin-resistant enterococcus risk factors were common in our patients: recent hospitalization in 16%, recent antibiotic exposure in 39%, and renal insufficiency in 7%. Seventeen percent were receiving SBP prophylaxis. Despite the presence of established risk factors, VRE colonization prevalence was 3.4%. Preliminary limited data showed poor correlation between screening rectal cultures and operative/peri-operative cultures. Vancomycin-resistant enterococcus colonization prevalence in an OLT candidate population with mid-level MELD scores was low, and SBP prophylaxis was not a significant risk factor.     

Positives MRSA-Screening – klinische Konsequenzen?

BACKGROUND: The worldwide rise of MRSA is equivalent to an increase of nasal colonization with MRSA. The objectives of this study were to investigate the rate of occult nasal MRSA colonization in trauma patients, to elucidate the role of MRSA carriers for endogenous infection (nose --> wound) and to check the efficiency of mupirocin therapy.PATIENTS AND METHODS: A total of 643 consecutive trauma patients underwent MRSA screening (nasal swabs) on admission. At the same time all MRSA wound infections were registered and all isolates were analysed with PFGE (pulsed-field gel electrophoresis) to detect cross-infection between individuals.RESULTS: In 13 patients (2.0%) we found MRSA in the nose and limited isolation as well as therapy with mupirocin were performed. No endogenous transmission of MRSA from the nose to the wound could be seen, and no cross-infection to other patients could be detected.CONCLUSION: Our findings suggest that in our patients with nasal colonization the risk of intra- and interindividual transmission of MRSA is very small. Therefore, in trauma patients screening on admission does not seem to be absolutely necessary either for clinical or for epidemiological reasons.