Staphylococcus aureus colonisation and strategies for decolonisation

Staphylococcus aureus is a leading cause of death by infectious diseases worldwide. Treatment of S aureus infections is difficult due to widespread antibiotic resistance, necessitating alternative approaches and measures for prevention of infection. Because S aureus infections commonly arise from asymptomatic colonisation, decolonisation is considered a key approach for their prevention. Current decolonisation procedures include antibiotic-based and antiseptic-based eradication of S aureus from the nose and skin. However, despite the widespread implementation and partial success of such measures, S aureus infection rates remain worrisome, and resistance to decolonisation agents is on the rise. In this Review we outline the epidemiology and mechanisms of S aureus colonisation, describe how colonisation underlies infection, and discuss current and novel approaches for S aureus decolonisation, with a focus on the latest findings on probiotic strategies and the intestinal S aureus colonisation site.

Comparison of global decolonization efficacy with mupirocin nasal drop and chlorhexidine mouthwash in acute leukemia patients: randomized clinical trial

PURPOSE

Neutropenic fever remains a major complication in acute leukemia. Decolonization is assumed as a promising intervention for eradicating causative agents of infection.

METHODS

In this randomized clinical trial, 96 patients with acute leukemia were assigned randomly to mupirocin nasal drop 2% (n = 32), chlorhexidine mouthwash 0.2% (n = 33), and control group (n = 31). In control group, patients did not receive any medication for decolonization. All patients received treatment for 5 days (2 days prior to chemotherapy until 3 days after chemotherapy). Pharynx and nasal swabs were taken prior to the intervention and at the end of decolonization period in all groups. Antibiotic susceptibility testing was performed by the disc diffusion method in order to identify bacterial isolates.

RESULTS

Bacterial recovery of both nasal and pharynx swabs was observed after global decolonization with mupirocin nasal drop. Decolonization with mupirocin significantly eradicated Coagulase-negative staphylococci (CONS) in both nasal and pharynx swabs (p-value = 0.000). Moreover, mupirocin decreased Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) species. Chlorhexidine mouthwash significantly eradicated CONS in pharynx swabs (p-value = 0.000). In addition, both decolonization strategies decreased both antibiotic use and frequency of fever in leukemic patients.

CONCLUSION

Global decolonization with mupirocin nasal drop not only eradicates both nasal and pharynx microorganisms, but also reduces antibiotic requirement and frequency of fever in patients with acute leukemia. The protocol of the present study was approved on December 2016 (registry number: IRCT20160310026998N6).

Nasal decolonization: What antimicrobials and antiseptics are most effective before surgery and in the ICU

BACKGROUND

Staphylococcus aureus colonization is a key risk factor for S. aureus infections in surgical patients and in hospitalized patients. Many studies have assessed various decolonization agents, protocols, and settings. This review summarizes key findings about nasal decolonization for 2 different patient populations: patients undergoing surgery and patients hospitalized in intensive care units.

METHODS

We reviewed major studies related to decolonization of patients colonized with S. aureus and who were either undergoing surgical procedures or were hospitalized in intensive care units. We focused on recent studies, particularly randomized controlled trials and robust quasi-experimental trials. We also reviewed select non-randomized trials when more rigorous trials were limited.

DISCUSSION/CONCLUSIONS

Mupirocin is the best-studied agent for decolonization. Its use reduces the risk of surgical site infection following orthopedic surgery (strongest data) and cardiac surgery. Mupirocin decolonization also reduces the incidence of S. aureus clinical cultures in the intensive care unit. Povidone-iodine is less well-studied. Current data suggest that it decreases the risk of surgical site infections after orthopedic surgical procedures. In contrast, povidone-iodine is less effective than mupirocin for reducing the incidence of S aureus clinical cultures in the intensive care unit. Both mupirocin and povidone-iodine have important limitations, highlighting the need for future decolonization research.

Exploring differentially expressed genes of Staphylococcus aureus exposed to human tonsillar cells using RNA sequencing

BACKGROUND

The nose and the throat are the most predominant colonizing sites of Staphylococcus aureus, and colonization is a risk factor for infection. Nasal colonization is well described; however, we have limited knowledge about S. aureus throat colonization. The main objective of this study was to explore differentially expressed genes (DEGs) in S. aureus throat isolate TR145 exposed to human tonsil epithelial cells (HTEpiC) by using RNA sequencing (RNA-seq) and pathway analysis. DEGs in S. aureus at 1 or 3 hours (h) interaction with its host were explored.

RESULTS

S. aureus was co-cultured in absence and presence of tonsillar cells at 1 or 3 h. Over the 3 h time frame, the bacteria multiplied, but still caused only minor cytotoxicity. Upon exposure to tonsillar cell line, S. aureus changed its transcriptomic profile. A total of 508 DEGs were identified including unique (1 h, 160 DEGs and 3 h, 78 DEGs) and commonly shared genes (1 and 3 h, 270 DEGs). Among the DEGs, were genes encoding proteins involved in adhesion and immune evasion, as well as iron acquisition and transport. Reverse transcription qPCR was done on selected genes, and the results correlated with the RNA-seq data.

CONCLUSION

We have shown the suitability of using HTEpiC as an in vitro model for investigating key determinants in S. aureus during co-incubation with host cells. Several DEGs were unique after 1 or 3 h exposure to host cells, while others were commonly expressed at both time points. As their expression is induced upon meeting with the host, they might be explored further for future targets for intervention to prevent either colonization or infection in the throat.

Clinical Evidence for the Use of Octenidine Dihydrochloride to Prevent Healthcare-Associated Infections and Decrease Staphylococcus aureus Carriage or Transmission-A Review

BACKGROUND

The antiseptic agent octenidine dihydrochloride (OCT) is used for skin preparation, for Staphylococcus aureus decolonization, and within bundles for the prevention of catheter-related or surgical site infections (SSIs). Here, we review the evidence for the effects of OCT from clinical studies.

METHODS

Review of studies published in the Medline, Scopus, and Cochrane databases until August 2022, performed in clinical settings and reporting on effects of OCT on S. aureus carriage/transmission, SSI prevention, and prevention of intensive care unit (ICU)-related or catheter-related bloodstream and insertion site infections.

RESULTS

We included 31 articles. The success of S. aureus decolonization with OCT-containing therapies ranged between 6 and 87%. Single studies demonstrated that OCT application led to a reduction in S. aureus infections, acquisition, and carriage. No study compared OCT for skin preparation before surgical interventions to other antiseptics. Weak evidence for the use of OCT for pre-operative washing was found in orthopedic and cardiac surgery, if combined with other topical measures. Mostly, studies did not demonstrate that daily OCT bathing reduced ICU-/catheter-related bloodstream infections with one exception.

CONCLUSIONS

There is a need to perform studies assessing the clinical use of OCT compared with other antiseptics with respect to its effectiveness to prevent nosocomial infections.

Staphylococcus aureus FadB is a dehydrogenase that mediates cholate resistance and survival under human colonic conditions

Staphylococcus aureus is a common colonizer of the human gut and in doing so it must be able to resist the actions of the host's innate defences. Bile salts are a class of molecules that possess potent antibacterial activity that control growth. Bacteria that colonize and survive in that niche must be able to resist the action of bile salts, but the mechanisms by which S. aureus does so are poorly understood. Here we show that FadB is a bile-induced oxidoreductase which mediates bile salt resistance and when heterologously expressed in Escherichia coli renders them resistant. Deletion of fadB attenuated survival of S. aureus in a model of the human distal colon.

Incidence and risk factors for surgical site infection (SSI) after primary hip hemiarthroplasty: an analysis of the ACS-NSQIP hip fracture procedure targeted database

INTRODUCTION

Primary hip hemiarthroplasty (HHA) is frequently utilized to treat geriatric hip fractures, which are associated with significantly higher morbidity and mortality. While not particularly common, surgical site infection (SSI) is a major complication that frequently requires revision surgery in a frail population. The objective of this study was to determine the incidence of and risk factors for SSI after HHA in hip fracture patients.

MATERIALS AND METHODS

This retrospective cohort study was performed using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Geriatric patients (65+) who underwent HHA for non-pathologic, traumatic hip fractures between 2016-2017 were included. Demographic variables, comorbidities, operative variables, and complications were compared between "SSI" and "non-SSI" groups. Multivariate regression identified independent risk factors for postoperative SSI. Significance was set at P = 0.05.

RESULTS

A total of 6169 patients were included. The overall incidence of SSI was 1.3%. SSI was significantly associated with body mass index (BMI), preoperative functional status, congestive heart failure, chronic corticosteroid use, intraoperative time, sepsis, wound dehiscence, readmission within 30-days, and reoperation. On multivariate analysis, chronic steroid use (OR: 2.30, 95% CI: 1.13-4.70), BMI ≥ 35 kg/m² (OR: 3.59, 95% CI: 1.57-8.18), and intraoperative time ≥120 mins (OR: 2.15, 95% CI: 1.08-4.27) were found to be independent risk factors.

CONCLUSIONS

Postoperative SSI is a serious complication that is responsible for prolonged hospital stays, increased mortality, and greater healthcare costs. Here, we identified multiple risk factors for SSI after primary HHA in the US elderly population.

30-day postoperative sepsis risk factors following laminectomy for intradural extramedullary tumors

BACKGROUND

Posterior laminectomy (LA) for resection of intradural extramedullary tumors (IDEMTs) is associated with postoperative complications, including sepsis. Sepsis is an uncommon but serious complication that can lead to increased morbidity and mortality, prolonged hospital stays, and greater costs. Given the susceptibility of a solid tumor patients to sepsis-related complications, it is important to recognize IDEMT patients as a unique population when assessing the risk factors for sepsis after laminectomy.

METHODS

The study design was a retrospective cohort study. Adult patients undergoing LA for IDEMTs from 2012 to 2018 were identified in the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Baseline patient characteristics/comorbidities, operative and hospital variables, and 30-day postoperative complications were collected.

RESULTS

Of 2,027 total patients undergoing LA for IDEMTs, 38 (2%) had postoperative sepsis. On bivariate analysis sepsis was associated with superficial surgical site infection [odds ratio (OR) 11.62, P<0.001], deep surgical site infection (OR 10.67, P<0.001), deep vein thrombosis (OR 10.75, P<0.001), pulmonary embolism (OR 15.27, P<0.001), transfusion (OR 6.18, P<0.001), length of stay greater than five days (OR 5.41, P<0.001), and return to the operating room within thirty days (OR 8.72, P<0.001). Subsequent multivariate analysis identified the following independent risk factors for sepsis and septic shock: operative time ≥50th percentile (OR 2.11, P=0.032), higher anesthesia class (OR 1.76, P=0.046), dependent functional status (OR 2.23, P=0.001), diabetes (OR 2.31, P=0.037), and chronic obstructive pulmonary disease (OR 3.56, P=0.037).

CONCLUSIONS

These findings can help spine surgeons identify high-risk patients and proactively deploy measures to avoid this potentially devastating complication in individuals who may be more vulnerable than the general elective spine population.

Enteral Vancomycin to Eliminate MRSA Carriership of the Digestive Tract in Critically Ill Patients

Background: Carriership with methicillin resistant Staphylococcus aureus (MRSA) is a risk for the development of secondary infections in critically ill patients. Previous studies suggest that enteral vancomycin is able to eliminate enteral carriership with MRSA. Data on individual effects of this treatment are lacking. Methods: Retrospective analysis of a database containing 15 year data of consecutive patients from a mixed medical-(cardio)surgical 18 bedded intensive care unit was conducted. All consecutive critically ill patients with enteral MRSA carriership detected in throat and/or rectal samples were collected. We analyzed those with follow-up cultures to determine the success rate of enteral vancomycin. Topical application of 2% vancomycin in a sticky oral paste was performed combined with a vancomycin solution of 500 mg four times daily in the nasogastric tube. This treatment was added to a regimen of selective digestive tract decontamination (SDD) to prevent ICU acquired infection. Results: Thirteen patients were included. The mean age was 65 years and the median APACHE II score was 21. MRSA was present in the throat in 8 patients and in both throat and rectum in 5 patients. In all patients MRSA was successfully eliminated from both throat and rectum, which took 2–11 days with a median duration until decontamination of 4 days. Secondary infections with MRSA did not occur. Conclusions: Topical treatment with vancomycin in a 2% sticky oral paste four times daily in the nasogastric tube was effective in all patients in the elimination of MRSA and prevented secondary MRSA infections.

OUP accepted manuscript

Background

Carriers of Staphylococcus aureus among healthcare workers (HCWs) can spread the bacteria to patients and the environment, in addition to their own risk of infection.

Objectives

To determine the prevalence of S. aureus carriers among HCWs and the rate of recolonization after decolonization therapy with mupirocin.

Methods

Nasal and hand swabs from HCWs of a tertiary care hospital in Nepal were cultured on mannitol salt agar and S. aureus isolated were identified using standard microbiological procedures. Detection of MRSA and mupirocin-resistant S. aureus (MupRSA) isolates were done phenotypically. Identified S. aureus carriers were decolonized with 2% mupirocin nasal ointment. Recolonization of the carriers was assessed monthly for the next 5 months.

Results

Among the 213 HCWs, 18.3% were S. aureus carriers (35 nasal carriers, 4 both nasal and hand carriers, and no hand carriers). Overall, 9.4% of the HCWS were MRSA carriers and none were MupRSA carriers. After decolonization, 25.6% of them were recolonized and 50.0% of the recolonization was detected after 3 months of decolonization. All recolonized carriers had only MSSA strains (which colonized only nose), and none were recolonized with MupRSA.

Conclusions

HCWs are frequent carriers of S. aureus and MRSA. Due to their continuous exposure to the hospital environment, they are at risk of colonization by this MDR organism. Regular screening and decolonization of HCWs working with high risk, vulnerable patients would reduce the risk of MRSA transmission from HCWs to patients.

Gastrointestinal colonization of methicillin-resistant Staphylococcus aureus: an unrecognized burden in the hospital infection control

The incidence, risk factors, outcomes, and genomic relatedness of patients with newly diagnosed gastrointestinal colonization of meticillin-resistant Staphylococcus aureus (MRSA) were analyzed epidemiologically and genetically by whole genome sequencing (WGS) in a hospital network in Hong Kong. Between 1 October 2015 and 31 December 2018, 919 (2.7%) of 34,667 patients had newly diagnosed gastrointestinal MRSA colonization by admission screening. The incidence was 0.67±0.32 per 1,000-patient-days-per-quarter. Including patients with gastrointestinal MRSA colonization, the overall burden of MRSA increased by 59.2% (from 1.13±0.13 to 1.80±0.36 case per 1,000-patient-days-per-quarter), with an addition of MRSA 4,727 patient-days during the study period. Patients referred from residential care home for the elderly [odds ratio (95% confidential interval): 4.18 (3.50-4.99), p<0.001], with history of hospitalization in the past 6 months [1.90 (1.56-2.30), p<0.001], and consumption of fluoroquinolones [1.76 (1.34-2.30), p<0.001], cephalosporins [1.61 (1.11-2.31), p=0.011], and proton pump inhibitors [1.31 (1.10-1.56), p=0.002] in the preceding 6 months were found to be independent risk factors by multivariable analysis in the case-control analysis. The median survival of case was significantly shorter than control (860 vs 1507 days, p<0.001). 127 (13.8%) of 919 patients developed symptomatic MRSA infection in 112 days (median, range: 2-712 days). Of 19 patients with paired MRSA faecal and blood culture isolates subjected to WGS, clonality was found in 16 (84.2%) pairs of MRSA isolates. MRSA ST45 constituted 44.7% (17/38) of MRSA isolates. Gastrointestinal MRSA colonization may contribute to adverse clinical outcomes and pose an unrecognized burden to the hospital infection control.

How to Prevent and Treat Complications in Facelift Surgery, Part 1: Short-Term Complications

This article provides a review of available evidence with regard to short-term complications in facelift surgery. The article reviews both the most common complications and less common, but well-described ones. The goal is to offer objective means to minimize postoperative complications and a guide for treatment when they occur.

Outpatient decolonization after recurrent skin infection with Panton-Valentine leukocidin (PVL)-producing S. aureus-The importance of treatment repetition

BACKGROUND

Recurrent skin abscesses are often associated with Panton-Valentine leukocidin-producing strains of S. aureus (PVL-SA). Decolonization measures are required along with treatment of active infections to prevent re-infection and spreading. Even though most PVL-SA patients are treated as outpatients, there are few studies that assess the effectiveness of outpatient topical decolonization in PVL-SA patients.

METHODS

We assessed the results of topical decolonization of PVL-SA in a retrospective review of patient files and personal interviews. Successful decolonization was defined as the absence of any skin abscesses for at least 6 months after completion of the final decolonization treatment. Clinical and demographic data was assessed. An intention-to-treat protocol was used.

RESULTS

Our cohort consisted of 115 symptomatic patients, 66% from PVL-positive MSSA and 19% from PVL-positive MRSA. The remaining 16% consisted of symptomatic patients with close contact to PVL-SA positive index patients but without detection of PVL-SA. The majority of patients were female (66%). The median age was 29.87% of the patients lived in multiple person households. Our results showed a 48% reduction in symptomatic PVL-SA cases after the first decolonization treatment. The results also showed that the decrease continued with each repeated decolonization treatment and reached 89% following the 5th treatment. A built multivariable Cox proportional-hazards model showed that the absence of PVL-SA detection (OR 2.0) and living in single person households (OR 2.4) were associated with an independently increased chance of successful decolonization.

CONCLUSION

In our cohort, topical decolonization was a successful preventive measure for reducing the risk of PVL-SA skin abscesses in the outpatient setting. Special attention should be given to patients living in multiple person households because these settings could confer a risk that decolonization will not be successful.

Antimicrobial photodynamic therapy effectiveness against susceptible and methicillin-resistant Staphylococcus aureus biofilms

BACKGROUND

Staphylococcus aureus have a great ability to become rapidly resistant to conventional antimicrobial therapies. This study evaluated the efficacy of antimicrobial photodynamic therapy (aPDT) mediated by Curcumin (Cur) and light-emitting diode (LED) in the inactivation of biofilms of methicillin susceptible and resistant S. aureus (MSSA and MRSA, respectively).

METHODS

Biofilms were treated with Cur (20, 40 or 80 μM) and illuminated with LED source (455 ± 3 nm; 5.28 J/cm²) (aPDT groups), or treated either with Cur or LED only. Other samples were not exposed to Cur or LED (negative control). The biofilms viability after all experimental conditions were evaluated by counting the number of colonies (CFU/mL) and XTT assay. Additional samples were also evaluated by LIVE/DEAD® staining using confocal laser scanning microscopy (CLSM). Data were analyzed by ANOVAs followed by the Games-Howell post hoc test (α = 0.05).

RESULTS

For both strains, all aPDT groups significantly reduced both CFU/mL and metabolic activity of biofilms compared to the negative control (p < 0.001). The results were enhanced when 80 μM of Cur was used. CLSM images showed that both bacteria biofilms submitted to aPDT had a large number of red-stained colonies, especially at aPDT80. In general, MRSA biofilms tended to be less susceptible to aPDT than MSSA biofilms.

CONCLUSIONS

It can be concluded that aPDT mediated by Cur and LED was an efficient method to inactivate 48 -h biofilms of both S. aureus strains.

Intersection of HIV and community-associated methicillin-resistant Staphylococcus aureus

The epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has evolved over the past approximately 20 years, with certain populations appearing to have disproportionate risk. Of concern is the potential worsening of S. aureus infections in light of the continued opioid crisis. This review will discuss how CA-MRSA has significantly impacted HIV-infected individuals and address additional factors and populations that are associated with increased risk for MRSA. It will review therapeutic options and infection control strategies as well as highlight how whole genome sequencing can be used to extend traditional epidemiologic analysis and ultimately, inform infection prevention efforts. Continued work identifying those at the highest risk for MRSA, what the best infection prevention settings are in community settings and how to effectively implement and target these strategies is needed. Ultimately, infection control efforts will likely need to extend beyond healthcare settings to effectively and sustainably reduce MRSA infections.

Conjugative and replicative biology of the Staphylococcus aureus antimicrobial resistance plasmid, pC02

Genetic transfer among bacteria propels rapid resistance to antibiotics and decreased susceptibility to antiseptics. Staphylococcus aureus is a common culprit of hospital and community acquired infections, and S. aureus plasmids have been shown to carry a multitude of antimicrobial resistance genes. We previously identified a novel conjugative, multidrug resistance plasmid, pC02, from the clinical S. aureus isolate C02. This plasmid contained the chlorhexidine resistance gene qacA, and we were able to demonstrate that conjugative transfer of pC02 imparted decreased chlorhexidine susceptibility to recipient strains. In silico sequence analysis of pC02 suggested that the plasmid is part of the pWBG749-family of conjugative plasmids and that it contains three predicted origins of transfer (oriT), two of which we showed were functional and could mediate plasmid transfer. Furthermore, depending on which oriT was utilized, partial transfer of pC02 was consistently observed. To define the ability of the pC02 plasmid to utilize different oriT sequences, we examined the mobilization ability of nonconjugative plasmid variants that were engineered to contain a variety of oriT family inserts. The oriT-OTUNa family was transferred at the highest frequency; additional oriT families were also transferred but at lower frequencies. Plasmid stability was examined, and the copy number of pC02 was defined using droplet digital PCR (ddPCR). pC02 was stably maintained at approximately 4 copies per cell. Given the conjugative plasticity of pC02, we speculate that this plasmid could contribute to the spread of antimicrobial resistance across Staphylococcal strains and species.

Conjugative Transfer of a Novel Staphylococcal Plasmid Encoding the Biocide Resistance Gene, qacA

Staphylococcus aureus is the leading cause of skin and soft tissue infections (SSTI). Some S. aureus strains harbor plasmids that carry genes that affect resistance to biocides. Among these genes, qacA encodes the QacA Multidrug Efflux Pump that imparts decreased susceptibility to chlorhexidine, a biocide used ubiquitously in healthcare facilities. Furthermore, chlorhexidine has been considered as a S. aureus decolonization strategy in community settings. We previously conducted a chlorhexidine-based SSTI prevention trial among Ft. Benning Army trainees. Analysis of a clinical isolate (C02) from that trial identified a novel qacA-positive plasmid, pC02. Prior characterization of qacA-containing plasmids is limited and conjugative transfer of those plasmids has not been demonstrated. Given the implications of increased biocide resistance, herein we characterized pC02. In silico analysis identified genes typically associated with conjugative plasmids. Moreover, pC02 was efficiently transferred to numerous S. aureus strains and to Staphylococcus epidermidis. We screened additional qacA-positive S. aureus clinical isolates and pC02 was present in 27% of those strains; other unique qacA-harboring plasmids were also identified. Ten strains were subjected to whole genome sequencing. Sequence analysis combined with plasmid screening studies suggest that qacA-containing strains are transmitted among military personnel at Ft. Benning and that strains carrying qacA are associated with SSTIs within this population. The identification of a novel mechanism of qacA conjugative transfer among Staphylococcal strains suggests a possible future increase in the prevalence of antiseptic tolerant bacterial strains, and an increase in the rate of infections in settings where these agents are commonly used.

Staphylococcus aureus in the nose and throat of Iowan families

The study objective was to determine the prevalence of Staphylococcus aureus colonisation in the nares and oropharynx of healthy persons and identify any risk factors associated with such S. aureus colonisation. In total 263 participants (177 adults and 86 minors) comprising 95 families were enrolled in a year-long prospective cohort study from one urban and one rural county in eastern Iowa, USA, through local newspaper advertisements and email lists and through the Keokuk Rural Health Study. Potential risk factors including demographic factors, medical history, farming and healthcare exposure were assessed. Among the participants, 25.4% of adults and 36.1% minors carried S. aureus in their nares and 37.9% of adults carried it in their oropharynx. The overall prevalence was 44.1% among adults and 36.1% for minors. Having at least one positive environmental site for S. aureus in the family home was associated with colonisation (prevalence ratio: 1.34, 95% CI: 1.07-1.66). The sensitivity of the oropharyngeal cultures was greater than that of the nares cultures (86.1% compared with 58.2%, respectively). In conclusion, the nares and oropharynx are both important colonisation sites for healthy community members and the presence of S. aureus in the home environment is associated with an increased probability of colonisation.

Update on infection control practices in cancer hospitals

Therapies in oncology have evolved rapidly over the last years. At the same pace, supportive care for patients receiving cancer therapy has also evolved, allowing patients to safely receive the newest advances in treatment in both an inpatient and outpatient basis. The recognition of the role of infection control and prevention (ICP) in the outcomes of patients living with cancer has been such that it is now a requirement for hospitals and involves multidisciplinary groups. Some unique aspects of ICP for patients with cancer that have gained momentum over the past few decades include catheter-related infections, multidrug-resistant organisms, community-acquired viral infections, and the impact of the health care environment on the horizontal transmission of organisms. Furthermore, as the potential for infections to cross international borders has increased, alertness for outbreaks or new infections that occur outside the area have become constant. As the future approaches, ICP in immunocompromised hosts will continue to integrate emerging disciplines, such as antibiotic stewardship and the microbiome, and new techniques for environmental cleaning and for controlling the spread of infections, such as whole-genome sequencing. CA Cancer J Clin 2018;000:000-000. © 2018 American Cancer Society.

Staphylococcal Protein A Contributes to Persistent Colonization of Mice with Staphylococcus aureus

Staphylococcus aureus persistently colonizes the nasopharynx in humans, which increases the risk for invasive diseases, such as skin infection and bacteremia. Nasal colonization triggers IgG responses against staphylococcal surface antigens; however, these antibodies cannot prevent subsequent colonization or disease. Here, we describe S. aureus WU1, a multilocus sequence type 88 (ST88) isolate that persistently colonizes the nasopharynx in mice. We report that staphylococcal protein A (SpA) is required for persistence of S. aureus WU1 in the nasopharynx. Compared to animals colonized by wild-type S. aureus, mice colonized with the Δspa variant mount increased IgG responses against staphylococcal colonization determinants. Immunization of mice with a nontoxigenic SpA variant, which cannot cross-link B cell receptors and divert antibody responses, elicits protein A-neutralizing antibodies that promote IgG responses against colonizing S. aureus and diminish pathogen persistence.IMPORTANCE Staphylococcus aureus persistently colonizes the nasopharynx in about one-third of the human population, thereby promoting community- and hospital-acquired infections. Antibiotics are currently used for decolonization of individuals at increased risk of infection. However, the efficacy of antibiotics is limited by recolonization and selection for drug-resistant strains. Here, we propose a model of how staphylococcal protein A (SpA), a B cell superantigen, modifies host immune responses during colonization to support continued persistence of S. aureus in the nasopharynx. We show that this mechanism can be thwarted by vaccine-induced anti-SpA antibodies that promote IgG responses against staphylococcal antigens and diminish colonization.

Evaluation and management of Staphylococcus aureus bacteriuria: an updated review

BACKGROUND AND AIMS

There is little guidance regarding the evaluation and management of patients with Staphylococcus aureus bacteriuria (SABU). Here, we aimed to provide an up-to-date review of the literature.

METHODS

We searched PubMed, Scopus, and clinical trial registries for articles evaluating the epidemiology of SABU, risk factors of SABU, the association of SABU with urinary tract infection, bacteremia and invasive S. aureus infections, and the management of patients with SABU.

RESULTS

S. aureus is an uncommon isolate in urine cultures. It is more common among certain patients, e.g., patients with indwelling urinary tract devices or prior urinary tract instrumentation. SABU may represent asymptomatic bacteriuria, primary urinary tract infection, or hematogenous seeding of the urinary tract associated with other foci of infection. SABU may also serve as the focus for subsequent bacteremia and invasive infections. We did not find any clinical trials regarding the management of patients with SABU.

CONCLUSIONS

Based on our review, we suggest an algorithmic approach for the evaluation and management of patients with SABU. However, evidence from clinical trials is lacking and there are several gaps in the current literature. These are discussed in this review.

Eradication of methicillin-resistant Staphylococcus aureus (MRSA) throat carriage: a randomised trial comparing topical treatment with rifampicin-based systemic therapy

Eradication of methicillin-resistant Staphylococcus aureus (MRSA) colonisation may prevent transmission of strains between patients and reduces the risk of clinical infection. Colonisation of the throat is associated with prolonged carriage and is more difficult to eradicate. An open randomised study was conducted to evaluate two eradication protocols. Patients with pharyngeal carriage of MRSA were enrolled at six Swedish centres during 4 years. One treatment group received oral rifampicin and either clindamycin or trimethoprim/sulfamethoxazole (SXT) for 7 days in combination with nasal mupirocin. Patients in the other group were treated with nasal mupirocin only. Patients in the same household were randomised together. Both groups followed a hygiene protocol including chlorhexidine washing. Cultures from the nares, perineum and throat were taken at baseline and then at 2 weeks, 2 months and 6 months after the end of treatment. A total of 28 patients received rifampicin-based systemic antibiotics and 24 subjects received mupirocin only. At follow-up 6 months after the end of treatment, 61% of patients and 50% of households in the systemic antibiotics group had culture results negative for MRSA. Significantly less patients (12%) and households (10%) became decolonised in the group receiving topical treatment only. A combination of rifampicin and either clindamycin or SXT was more effective in eliminating pharyngeal MRSA carriage compared with topical treatment with mupirocin only.

Epidemiology and clinical relevance of Staphylococcus aureus intestinal carriage: a systematic review and meta-analysis

Recent data highlight the importance of screening more than one site for improving the detection of S. aureus colonization. Intestinal carriage is frequently under-investigated and its clinical impact ought to be defined a better way. Areas covered: This review and meta-analysis provide an updated overview of prevalence, characteristics and clinical significance of S. aureus intestinal carriage in different populations, both for methicillin-susceptible and -resistant S. aureus strains. Expert commentary: Intestinal S. aureus carriage is documented with higher prevalence in children and in patients with S. aureus skin and soft tissue infections. This site of colonization was shown to be associated with a high risk of dissemination in the environment and with S. aureus infection. Intestinal carriage is frequently retrieved in nasal carriers, reflecting probably an association with a high bacterial load. Exclusive intestinal carriage present in one third of intestinal carriers can be associated with infection. Comparative genotyping analysis of different strains from nasal and extra-nasal sites of carriage, including the intestinal ones, in the same individuals, would allow a better comprehension of the pathophysiology of S. aureus endogenous infection. It could also permit to improve the prevention of these infections by decolonization of sites implicated in infection genesis.

Microbiological efficacy of early MRSA treatment in cystic fibrosis in a randomised controlled trial

OBJECTIVE

To evaluate microbiological effectiveness, that is, culture negativity of a non-blinded eradication protocol (Rx) compared with observation (Obs) in clinically stable cystic fibrosis participants with newly positive methicillin resistant Staphylococcusaureus (MRSA) cultures.

DESIGN

This non-blinded trial randomised participants ages 4-45 years with first or early (≤2 positive cultures within 3 years) MRSA-positive culture without MRSA-active antibiotics within 4 weeks 1:1 to Rx or Obs. The Rx protocol was: oral trimethoprim-sulfamethoxazole or if sulfa-allergic, minocycline plus oral rifampin; chlorhexidine mouthwash for 2 weeks; nasal mupirocin and chlorhexidine body wipes for 5 days and environmental decontamination for 21 days. The primary end point was MRSA culture status at day 28.

RESULTS

Between 1 April 2011 to September 2014, 45 participants (44% female, mean age 11.5 years) were randomised (24 Rx, 21 Obs). At day 28, 82% (n=18/22) of participants in the Rx arm compared with 26% (n=5/19) in the Obs arm were MRSA-negative. Adjusted for interim monitoring, this difference was 52% (95% CI 23% to 80%, p<0.001). Limiting analyses to participants who were MRSA-positive at the screening visit, 67% (8/12) in the Rx arm and 13% (2/15) in the Obs arm were MRSA-negative at day 28, adjusted difference: 49% (95% CI 22% to 71%, p<0.001). Fifty-four per cent in the Rx arm compared with 10% participants in the Obs arm remained MRSA-negative through day 84. Mild gastrointestinal side effects were higher in the Rx arm.

CONCLUSIONS

This MRSA eradication protocol for newly acquired MRSA demonstrated microbiological efficacy with a large treatment effect.

TRIAL REGISTRATION NUMBER

NCT01349192.

The effect of vancomycin powder on human dural fibroblast culture and its implications for dural repair during spine surgery

OBJECTIVE

Surgical site infections (SSIs) are a major source of morbidity after spinal surgery. Several recent studies have described the finding that applying vancomycin powder to the surgical bed may reduce the incidence of SSI. However, applying vancomycin in high concentrations has been shown in vitro to inhibit osteoblast proliferation and to induce cell death. Vancomycin may have a deleterious effect on dural healing after repair of an intentional or unintentional durotomy. This study was therefore undertaken to assess the effect of different concentrations of vancomycin on a human dura mater cell culture.

METHODS

Human dura intended for disposal after decompressive craniectomy was harvested. Explant primary cultures and subcultures were subsequently performed. Cells were characterized through common staining and immunohistochemistry. A growth curve was performed to assess the effect of different concentrations of vancomycin (40, 400, and 4000 μg/ml) on cell count. The effect of vancomycin on cellular shape, intercellular arrangement, and viability was also evaluated.

RESULTS

All dural tissue samples successfully developed into fusiform cells, demonstrating pseudopod projections and spindle formation. The cells demonstrated vimentin positivity and also had typical features of fibroblasts. When applied to the cultures, the highest dose of vancomycin induced generalized cell death within 24 hours. The mean (± SD) cell counts for control, 40, 400, and 4000 μg/ml were 38.72 ± 15.93, 36.28 ± 22.87, 19.48 ± 6.53, and 4.07 ± 9.66, respectively (p < 0.0001, ANOVA). Compared with controls, vancomycin-exposed cells histologically demonstrated a smaller cytoplasm and decreased pseudopodia formation resulting in the inhibition of normal spindle intercellular arrangement.

CONCLUSIONS

When vancomycin powder is applied locally, dural cells are exposed to a concentration several times greater than when delivered systemically. In this in vitro model, vancomycin induced dural cell death, inhibited growth, and altered cellular morphology in a concentration-dependent fashion. Defining a safe vancomycin concentration that is both bactericidal and also does not inhibit normal dural healing is necessary.

Multidrug-Resistant Organisms Detected More Than 48 Hours After Hospital Admission Are Not Necessarily Hospital-Acquired

BACKGROUND Infections and colonization with multidrug-resistant organisms (MDROs) identified >48 hours after hospital admission are considered healthcare-acquired according to the definition of the Centers for Disease Control and Prevention (CDC). Some may originate from delayed diagnosis rather than true acquisition in the hospital, potentially diluting the impact of infection control programs. In addition, such infections are not necessarily reimbursed in a healthcare system based on the diagnosis-related groups (DRGs). OBJECTIVE The goal of the study was to estimate the preventable proportion of healthcare-acquired infections in a tertiary care hospital in Switzerland by analyzing patients colonized or infected with MDROs. METHODS All hospitalized patients with healthcare-acquired MDRO infection or colonization (HAMIC) or according to the CDC definition (CDC-HAMIC) were prospectively assessed from 2002 to 2011 to determine whether there was evidence for nosocomial transmission. We utilized an additional work-up with epidemiological, microbiological, and molecular typing data to determine the true preventable proportion of HAMICs. RESULTS Overall, 1,190 cases with infection or colonization with MDROs were analyzed; 274 (23.0%) were classified as CDC-HAMICs. Only 51.8% of CDC-HAMICs had confirmed evidence of hospital-acquisition and were considered preventable. Specifically, 57% of MRSA infections, 83.3% of VRE infections, 43.9% of ESBL infections, and 74.1% of non-ESBL MDRO infections were preventable HAMICs. CONCLUSIONS The CDC definition overestimates the preventable proportion of HAMICs with MDROs by more than 50%. Relying only on the CDC definition of HAMICs may lead to inaccurate measurement of the impact of infection control interventions and to inadequate reimbursement under the DRG system. Infect. Control Hosp. Epidemiol. 2016;1-6.

Approach to Decrease Infection Following Total Joint Arthroplasty

Surgical site infection in total joint arthroplasty is a challenging complication that warrants discussion with regard to prevention and management. Limiting postoperative infection rate is a paramount quest in the orthopedic community. Several preoperative risk factors have been identified in orthopedic literature with regards to likelihood of developing postoperative infection. This article evaluates several factors that predispose total joint arthroplasty patients to infection. Methods of patient surgical preparation designed to decrease postoperative infection, decreasing intraoperative traffic during procedural settings, and elaborate intraoperative prophylactic advancements are assessed. Approaches to decrease postoperative infection by discussing means of lowering rates of postoperative transfusion, wound drainage, and hematoma formation are analyzed.

Reducing Length of Stay in Total Joint Arthroplasty Care

As health care reforms continue to improve quality of care, significant emphasis will be placed on evaluation of orthopedic patient outcomes. Total joint arthroplasty (TJA) has a proven track record of enhancing patient quality of life and are easily replicable. The outcomes of these procedures serve as a measure of health care initiative success. Specifically, length of stay, will be targeted as a marker of quality of surgical care delivered to TJA patients. Within this review, we will discuss preoperative and postoperative methods by which orthopedic surgeons may enhance TJA outcomes and effectively reduce length of stay.

Prevention of Recurrent Staphylococcal Skin Infections

Staphylococcus aureus infections pose a significant health burden. The emergence of community-associated methicillin-resistant S aureus has resulted in an epidemic of skin and soft tissue infections (SSTI), and many patients experience recurrent SSTI. As S aureus colonization is associated with subsequent infection, decolonization is recommended for patients with recurrent SSTI or in settings of ongoing transmission. S aureus infections often cluster within households, and asymptomatic carriers serve as reservoirs for transmission; therefore, a household approach to decolonization is more effective than measures performed by individuals alone. Novel strategies for the prevention of recurrent SSTI are needed.

Methicillin-resistant Staphylococcus aureus: Prevalence, incidence, risk factors, and effects on survival of patients in a specialist palliative care unit: A prospective observational study

BACKGROUND

Little is known about the impact of methicillin-resistant Staphylococcus aureus in palliative care settings. To date, the clinical impact of methicillin-resistant Staphylococcus aureus in palliative care is unknown.

AIM

To determine prevalence and incidence of methicillin-resistant Staphylococcus aureus colonisation in a specialist palliative care setting, to identify risk factors for methicillin-resistant Staphylococcus aureus colonisation, to determine the eradication success rate and to determine the impact of methicillin-resistant Staphylococcus aureus on survival.

DESIGN

Prospective cohort study.

SETTING/PARTICIPANTS

Data were collected for consecutive admissions to an inpatient palliative care service. Patients were screened for methicillin-resistant Staphylococcus aureus colonisation on admission and 1 week post admission. Methicillin-resistant Staphylococcus aureus eradication was attempted in methicillin-resistant Staphylococcus aureus positive patients.

RESULTS

Data were collected from 609 admissions for 466 individual patients. Admission screening data were available in 95.5%. Prevalence of methicillin-resistant Staphylococcus aureus colonisation was 11.59% (54 patients). One week incidence of methicillin-resistant Staphylococcus aureus colonisation was 1.2%. Risk factors for methicillin-resistant Staphylococcus aureus colonisation were determined using Chi-Squared test and included high Waterlow score (p < 0.01), high palliative performance scale score (p < 0.01), methicillin-resistant Staphylococcus aureus status prior to admission (p < 0.01), admission from hospital (p < 0.05), presence of urinary catheter or percutaneous endoscopic gastrostomy tube (p < 0.05) and poor dietary intake (p < 0.05). Regression analysis did not identify independent risk factors. Methicillin-resistant Staphylococcus aureus was eradicated in 8.1% of admissions, while 46 patients commenced on the protocol (62.2%) died before completing it. Methicillin-resistant Staphylococcus aureus did not significantly impact survival but was significantly associated with having infection episodes and longer length of stay.

CONCLUSION

This study identified risk factors for methicillin-resistant Staphylococcus aureus colonisation in palliative care patients. Methicillin-resistant Staphylococcus aureus was eradicated in 8.1% of patients. Hence, restricting methicillin-resistant Staphylococcus aureus screening to high-risk palliative care patients may be prudent.

Beyond the Intensive Care Unit (ICU): Countywide Impact of Universal ICU Staphylococcus aureus Decolonization

A recent trial showed that universal decolonization in adult intensive care units (ICUs) resulted in greater reductions in all bloodstream infections and clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) than either targeted decolonization or screening and isolation. Since regional health-care facilities are highly interconnected through patient-sharing, focusing on individual ICUs may miss the broader impact of decolonization. Using our Regional Healthcare Ecosystem Analyst simulation model of all health-care facilities in Orange County, California, we evaluated the impact of chlorhexidine baths and mupirocin on all ICU admissions when universal decolonization was implemented for 25%, 50%, 75%, and 100% of ICU beds countywide (compared with screening and contact precautions). Direct benefits were substantial in ICUs implementing decolonization (a median 60% relative reduction in MRSA prevalence). When 100% of countywide ICU beds were decolonized, there were spillover effects in general wards, long-term acute-care facilities, and nursing homes resulting in median 8.0%, 3.0%, and 1.9% relative MRSA reductions at 1 year, respectively. MRSA prevalence decreased by a relative 3.2% countywide, with similar effects for methicillin-susceptible S. aureus. We showed that a large proportion of decolonization's benefits are missed when accounting only for ICU impact. Approximately 70% of the countywide cases of MRSA carriage averted after 1 year of universal ICU decolonization were outside the ICU.

Randomized, placebo-controlled, double-blind clinical trial to evaluate the efficacy of polyhexanide for topical decolonization of MRSA carriers

OBJECTIVES

The objective of this study was to evaluate the efficacy of polyhexanide (Prontoderm(®)) in eliminating MRSA carriage.

METHODS

In a 1900 bed teaching hospital, MRSA-colonized patients were randomized into a double-blind, placebo-controlled superiority trial between January 2011 and July 2014. Patients were treated with either polyhexanide or placebo applied to the anterior nares (thrice daily) and skin (once daily) for 10 days. The primary outcome was MRSA decolonization at day 28 (D28) after the end of treatment assessed by ITT responder and PP analyses (microbiological follow-up ± 7 days and topical treatment ≥ 5 days). Secondary outcomes included safety, emergence of resistance and MRSA genotype changes. Registered trial number ISRCTN02288276.

RESULTS

Of 2590 patients screened, 146 (polyhexanide group, 71; placebo group, 75) were included. ITT analysis showed that 24/71 (33.8%) patients in the polyhexanide group versus 22/75 (29.3%) in the placebo group were MRSA-free at D28 (risk difference, 4.5%; 95% CI, -10.6% to 19.5%; P = 0.56). PP analysis confirmed the results with 19/53 (35.8%) decolonized polyhexanide-treated patients versus 17/56 (30.4%) in the placebo arm (risk difference, 5.5%; 95% CI, -12.2% to 23%; P = 0.54). Nine serious adverse events occurred in the polyhexanide group versus 12 in the placebo group; none was attributable to study medication. Emergence of polyhexanide resistance or cross-resistance between polyhexanide and chlorhexidine was not observed. No case of exogenous recolonization by a genotypically different MRSA strain was documented.

CONCLUSIONS

This study suggests that under real-life conditions, a single polyhexanide decolonization course is not effective in eradicating MRSA carriage.

The Stealthy Superbug: the Role of Asymptomatic Enteric Carriage in Maintaining a Long-Term Hospital Outbreak of ST228 Methicillin-Resistant Staphylococcus aureus

Whole-genome sequencing (WGS) of 228 isolates was used to elucidate the origin and dynamics of a long-term outbreak of methicillin-resistant Staphylococcus aureus (MRSA) sequence type 228 (ST228) SCCmec I that involved 1,600 patients in a tertiary care hospital between 2008 and 2012. Combining of the sequence data with detailed metadata on patient admission and movement confirmed that the outbreak was due to the transmission of a single clonal variant of ST228, rather than repeated introductions of this clone into the hospital. We note that this clone is significantly more frequently recovered from groin and rectal swabs than other clones (P < 0.0001) and is also significantly more transmissible between roommates (P < 0.01). Unrecognized MRSA carriers, together with movements of patients within the hospital, also seem to have played a major role. These atypical colonization and transmission dynamics can help explain how the outbreak was maintained over the long term. This "stealthy" asymptomatic colonization of the gut, combined with heightened transmissibility (potentially reflecting a role for environmental reservoirs), means the dynamics of this outbreak share some properties with enteric pathogens such as vancomycin-resistant enterococci or Clostridium difficile.

IMPORTANCE

Using whole-genome sequencing, we showed that a large and prolonged outbreak of methicillin-resistant Staphylococcus aureus was due to the clonal spread of a specific strain with genetic elements adapted to the hospital environment. Unrecognized MRSA carriers, the movement of patients within the hospital, and the low detection with clinical specimens were also factors that played a role in this occurrence. The atypical colonization of the gut means the dynamics of this outbreak may share some properties with enteric pathogens.

Efficacy of the decolonization of methicillin-resistant Staphylococcus aureus carriers in clinical practice

BACKGROUND

Nasal and extra nasal carriage of methicillin-resistant S. aureus (MRSA) is a pre-existing condition that often leads to invasive MRSA infection, as MRSA colonization is associated with a high risk of acquiring MRSA infection during hospital stays. Decolonization may reduce the risk of meticillin-resistant Staphylococcus aureus (MRSA) infection in individual carriers and prevent transmission to other patients.

METHODS

A retrospective cohort study was conducted to evaluate the effectiveness of two decolonization protocols for newly diagnosed MRSA carriage in hospitalized patients and to assess the impact of decolonization on the rate of MRSA infection. The study population consisted of all patients diagnosed as MRSA-positive between January 2006 and June 2010. Patients diagnosed as carriers were designated as requiring contact precautions by the hospital infection control team. The standing order protocol of the hospital pertaining to decolonization procedures was then applied, and all newly diagnosed patients were administered one of the two decolonization treatments outlined in the hospital protocol, with the exception of MRSA respiratory carriers (MRSA obtained from sputum or other lower respiratory tract samples). The two decolonization treatments consisted of the application of intranasal mupirocin 2 % and washing with chlorhexidine soap (40 mg/mL) (mupi/CHX) or application of intranasal povidone-iodine and washing with povidone-iodine soap (PVPI), with each treatment lasting for 5 days. Success was determined by at least three successive nose swabs and throat and other screened site swabs that tested negative for MRSA before patient discharge.

RESULTS

A total of 1150 patients admitted to the hospital were found to be infected or colonized with MRSA. Of the 1150 patients, 268 were prescribed decolonization treatment. 104 out of 268 patients (39 %) were successfully decolonized. There was no significant success after two decolonization failures. MRSA infection rate among the successes and failures were 0.0 and 4.3 %, respectively [P = 0.04].

CONCLUSIONS

Our results fit well with the prescription of decolonization based on local strategy protocols but reflect a low rate of successful treatment. Although the success rate of decolonization was not high in our study, the effectiveness of decolonization on the infection rate, justifies the continuation of this strategy, even if a marginal cost is incurred.

High prevalence of methicillin resistance and PVL genes among Staphylococcus aureus isolates from the nares and skin lesions of pediatric patients with atopic dermatitis

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmectyping, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureusisolates from skin infections. Methicillin-resistant S. aureus(MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.

Nasal methicillin-resistant Staphylococcus aureus colonization is associated with increased wound occurrence after major lower extremity amputation

OBJECTIVE

Wound occurrence (WO) after major lower extremity amputation (MLEA) can be due to wound infection or sterile dehiscence. We sought to determine the association of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization and other patient factors with overall WO, WO due to wound infection, and WO due to sterile dehiscence.

METHODS

The medical records of all patients undergoing MLEA from August 1, 2011, to November 1, 2013, were reviewed. Demographic data, hemoglobin A1c level, albumin concentration, dialysis dependence, peripheral vascular disease (PVD), nasal MRSA colonization, and diabetes mellitus (DM) were examined as variables. The overall WO rate was determined, and the cause of WO was categorized as either a sterile dehiscence or a wound infection.

RESULTS

Eighty-three patients underwent 96 MLEAs during a 27-month period. The rates of overall WO, WO due to infection, and WO due to sterile dehiscence were 39%, 19%, and 19%, respectively (1% developed a traumatic wound). On univariate analysis, PVD, MRSA colonization, DM, and dialysis dependence were all associated with higher rates of overall WO (P < .05). On multivariate analysis, MRSA colonization was associated with higher rates of overall WO (P = .03) and WO due to wound infection (11% vs 45%; P < .01). DM and PVD were associated with higher rates of overall WO and WO due to sterile dehiscence on both univariate and multivariate analysis (P < .05).

CONCLUSIONS

Nasal MRSA colonization is associated with higher rates of overall WO and WO due to wound infection. DM and PVD are associated with higher rates of overall WO and WO due to sterile dehiscence but are not associated with WO due to wound infection. Further studies addressing the effect of nasal MRSA eradication on postoperative wound outcomes after MLEA are warranted.

Cutaneous manifestations of human immunodeficiency virus: a clinical update

Dermatologic diseases are common in the HIV-infected population. Many of the cutaneous diseases are not unique to this group, but the presentation can be more severe. Although the introduction of antiretroviral therapy has been followed by a decline in many of the skin diseases associated with HIV, drug reactions and other non-infectious skin conditions have increased. This article reviews the current spectrum of HIV-associated skin conditions, focusing on common complaints, infections, drug-associated toxicity and malignancies.

Strict infection control leads to low incidence of methicillin-resistant Staphylococcus aureus bloodstream infection over 20 years

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) is a worldwide issue associated with significant morbidity and mortality. Multiple infection control (IC) approaches have been tested to control its spread; however, the success of the majority of trials has been short-lived and many efforts have failed. We report the long-term success of MRSA control from a prospective observational study over 20 years.

SETTING

University Hospital Basel is a large tertiary care center with a median bed capacity of 855 and 5 intensive care units (ICUs); currently, the facility has >32,000 admissions per year.

METHODS

The IC program at the University Hospital Basel was created in 1993, after 2 MRSA outbreaks. The program has included strict contact precautions with single rooms for MRSA-colonized or -infected patients, targeted admission screening of high-risk patients and healthcare workers at risk for carriage, molecular typing of all MRSA strains and routine decolonization of MRSA carriers including healthcare workers. We used the incidence of MRSA bloodstream infections (BSIs) to assess the effectiveness of this program. All MRSA cases were prospectively classified using a standardized case report form in nosocomial and nonnosocomial cases, based on CDC definitions.

RESULTS

Between 1993 and 2012, 540,669 blood samples were cultured. The number of blood cultures increased from 865 per 10,000 patient days in 1993 to 1,568 per 10,000 patient days in 2012 (P<.001). We identified 1,268 episodes of S. aureus BSI from 1,204 patients. MRSA accounted for 34 episodes (2.7%) and 24 of these (1.9%) were nosocomial. MRSA BSI incidence varied between 0 and 0.27 per 10,000 patient days and remained stable with no significant variation throughout the study period (P=.882).

CONCLUSIONS

Long-term control of MRSA is feasible when a bundle of IC precautions is strictly enforced over time.

An Outbreak of Heterogeneous Glycopeptide-IntermediateStaphylococcus aureusRelated to a Device Source in an Intensive Care Unit

Objective.

The emergence ofStaphylococcus aureuswith reduced susceptibility to glycopeptides (glycopeptide-intermediateS. aureus[GISA] and heterogeneous GISA [h-GISA]) leads to intensive care unit (ICU) outbreaks that frequently result in ward closure. We investigated the role of hospital hygiene in the transmission and eradication of an h-GISA outbreak.

Design.

The study is a description of an original environmental investigation around a series of 12 cases.

Setting and Patients.

The outbreak occurred in a 20-bed polyvalent/trauma ICU in a 2,800-bed tertiary care university hospital in France.

Interventions.

Specimens were obtained for surveillance and diagnostic cultures from all patients in the unit. Surface sampling was also performed. Geographic cohorting, contact isolation, emphasis on adherence to infection control practices, and environmental cleaning were implemented.

Results.

Twelve patients with h-GISA infection (n= 5) or colonization (n= 7) were identified. The mean interval between admission and h-GISA detection was 23.6 days (range, 10–89 days), with a median of 16.5 days. Environmental investigation identified an unexpected reservoir, namely, SpO2sensors. The outbreak was controlled by a combination of measures, including eradication of this reservoir, avoiding total ward closure.

Conclusions.

Targeted surface sampling helps to secure the environment through active investigation of various reservoirs while maintaining normal activity on the ward. In our study, this method led to the detection of an unsuspected reservoir, the eradication of which helped control the h-GISA epidemic. Further applications of this original investigative procedure should allow confirmation of its relevance and efficiency.

Infect Control Hosp Epidemiol2012;33(2):167-174

Systematic literature analysis and review of targeted preventive measures to limit healthcare-associated infections by meticillin-resistant Staphylococcus aureus

Meticillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections in Europe. Many examples have demonstrated that the spread of MRSA within healthcare settings can be reduced by targeted infection control measures. The aim of this systematic literature analysis and review was to summarise the evidence for the use of bacterial cultures for active surveillance the benefit of rapid screening tests, as well as the use of decolonisation therapies and different types of isolation measures. We included 83 studies published between 2000 and 2012. Although the studies reported good evidence supporting the role of active surveillance followed by decolonisation therapy, the effectiveness of single-room isolation was mostly shown in non-controlled studies, which should inspire further research regarding this issue. Overall, this review highlighted that when planning the implementation of preventive interventions, there is a need to consider the prevalence of MRSA, the incidence of infections, the competing effect of standard control measures (e.g. hand hygiene) and the likelihood of transmission in the respective settings of implementation.