Legislative Mandates for Use of Active Surveillance Cultures to Screen for Methicillin-ResistantStaphylococcus aureusand Vancomycin-Resistant Enterococci: Position Statement From the Joint SHEA and APIC Task Force

Legislation aimed at controlling antimicrobial-resistant pathogens through the use of active surveillance cultures to screen hospitalized patients has been introduced in at least 2 US states. In response to the proposed legislation, the Society for Healthcare Epidemiology of America (SHEA) and the Association of Professionals in Infection Control and Epidemiology (APIC) have developed this joint position statement. Both organizations are dedicated to combating healthcare-associated infections with a wide array of methods, including the use of active surveillance cultures in appropriate circumstances. This position statement reviews the proposed legislation and the rationale for use of active surveillance cultures, examines the scientific evidence supporting the use of this strategy, and discusses a number of unresolved issues surrounding legislation mandating use of active surveillance cultures. The following 5 consensus points are offered. (1) Although reducing the burden of antimicrobial-resistant pathogens, including methicillin-resistantStaphylococcus aureus(MRSA) and vancomycin-resistant enterococci (VRE), is of preeminent importance, APIC and SHEA do not support legislation to mandate use of active surveillance cultures to screen for MRSA, VRE, or other antimicrobial-resistant pathogens. (2) SHEA and APIC support the continued development, validation, and application of efficacious and cost-effective strategies for the prevention of infections caused by MRSA, VRE, and other antimicrobial-resistant and antimicrobial-susceptible pathogens. (3) APIC and SHEA welcome efforts by healthcare consumers, together with private, local, state, and federal policy makers, to focus attention on and formulate solutions for the growing problem of antimicrobial resistance and healthcare-associated infections. (4) SHEA and APIC support ongoing additional research to determine and optimize the appropriateness, utility, feasibility, and cost-effectiveness of using active surveillance cultures to screen both lower-risk and high-risk populations. (5) APIC and SHEA support stronger collaboration between state and local public health authorities and institutional infection prevention and control experts.

A Cost-Benefit Analysis of Gown Use in Controlling Vancomycin-ResistantEnterococcusTransmission Is It Worth the Price?

Objective:

To determine the net benefit and costs associated with gown use in preventing transmission of van-comycin-resistantEnterococcus(VRE).

Design:

A cost-benefit analysis measuring the net benefit of gowns was performed. Benefits, defined as averted costs from reduced VRE colonization and infection, were estimated using a matched cohort study. Data sources included a step-down cost allocation system, hospital informatics, and microbiology databases.

Setting:

The medical intensive care unit (MICU) at Barnes-Jewish Hospital, St. Louis, Missouri.

Patients:

Patients admitted to the MICU for more than 24 hours from July 1, 1997, to December 31, 1999.

Interventions:

Alternating periods when all healthcare workers and visitors were required to wear gowns and gloves versus gloves alone on entry to the rooms of patients colonized or infected with VRE.

Results:

On base-case analysis, 58 VRE cases were averted with gown use during 18 months. The annual net benefit of the gown policy was $419,346 and the cost per case averted of VRE was $1,897. The analysis was most sensitive to the level of VRE transmission.

Conclusions:

Infection control policies (eg, gown use) initially increase the cost of health services delivery. However, such policies can be cost saving by averting nosocomial infections and the associated costs of treatment. The cost savings to the hospital plus the benefits to patients and their families of avoiding nosocomial infections make effective infection control policies a good investment.

Politically Incorrect: Legislation Must Not Mandate Specific Healthcare Epidemiology and Infection Prevention and Control Practices

In this issue of the journal, Dr. Farr offers his perspective on the recent position statement from the Joint SHEA and APIC Task Force regarding legislative mandates for use of active surveillance cultures to screen for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The position statement specifically addresses the issue of whether the use of MRSA and VRE surveillance cultures in healthcare settings should be mandated by legislation. It does not attempt to address whether or not, when, or for whom active surveillance cultures should be performed. A broad range of experts and the Boards of Directors of the Society for Healthcare Epidemiology (SHEA) and the Association of Professionals in Infection Control (APIC) reviewed this position statement, which summarizes the effectiveness of active surveillance culturing as it pertains to potential legislation. Both Boards agree the position statement represents a well-reasoned, systematic, and fair review of the literature. Of course, no single document, group, or individual should ever be viewed as having the final word on this or any subject. Thoughtful debate regarding the scientific evidence, when conducted in a professional and constructive manner, is a critical and necessary step in the translation of research and clinical observations into bedside practices. Such debate should also lead to a research agenda that will help fill gaps in knowledge that become apparent in the discussion.

Potential aquaculture probiont Lactococcus lactis TW34 produces nisin Z and inhibits the fish pathogen Lactococcus garvieae

Bacteriocin-producing Lactococcus lactis TW34 was isolated from marine fish. TW34 bacteriocin inhibited the growth of the fish pathogen Lactococcus garvieae at 5 AU/ml (minimum inhibitory concentration), whereas the minimum bactericidal concentration was 10 AU/ml. Addition of TW34 bacteriocin to L. garvieae cultures resulted in a decrease of six orders of magnitude of viable cells counts demonstrating a bactericidal mode of action. The direct detection of the bacteriocin activity by Tricine-SDS-PAGE showed an active peptide with a molecular mass ca. 4.5 kDa. The analysis by MALDI-TOF-MS detected a strong signal at m/z 2,351.2 that corresponded to the nisin leader peptide mass without the initiating methionine, whose sequence STKDFNLDLVSVSKKDSGASPR was confirmed by MS/MS. Sequence analysis of nisin structural gene confirmed that L. lactis TW34 was a nisin Z producer. This nisin Z-producing strain with probiotic properties might be considered as an alternative in the prevention of lactococcosis, a global disease in aquaculture systems.

Propionibacterium Acnes Infections After Cranial Neurosurgery

Background:

Propionibacterium acnes (P. acnes) is a relatively avirulent organism that is part of the normal skin flora. Most patient isolates are considered contaminants but, in a small subset of patients, particularly in the post-neurosurgery setting, the organism can cause significant infections. We reviewed our experience with the occurrence and management of P. acnes infections after cranial neurosurgical procedures over a five-year period.

Methods:

Patients with positive cultures for P. acnes between 1996 and 2001 were identified by review of the Saskatoon Health Region microbiology laboratory database. Of the 141 positive cultures, a review of hospital records identified six patients with P. acnes infections after neurosurgical procedures. A review of the literature related to P. acnes associated CNS infections was conducted.

Results:

All patients had undergone a craniotomy or burrhole placement, and one patient had received prior radiotherapy. There were no P. acnes-related ventriculoperitoneal shunt infections. All patients presented with scalp swelling and three had purulent discharge. Symptoms occurred more than two months after the initial surgery in five of six patients, while one patient developed symptoms three years post-operatively. Management for all patients included removal of the craniotomy flap and treatment with parenteral antibiotics, followed in most cases by oral antibiotics. A good response without relapse of infection was seen in five patients; one patient had recurrent infection after cranioplasty.

Conclusion:

P. acnes is a rare but important cause of infection after craniotomy. Wound debridement, removal of the bone flap and adequate antibiotic coverage result in cure in the majority of patients.

Identification of peptidoglycan-associated proteins as vaccine candidates for enterococcal infections

Infections by opportunistic bacteria have significant contributions to morbidity and mortality of hospitalized patients and also lead to high expenses in healthcare. In this setting, one of the major clinical problems is caused by Gram-positive bacteria such as enterococci and staphylococci. In this study we extract, purify, identify and characterize immunogenic surface-exposed proteins present in the vancomycin resistant enterococci (VRE) strain Enterococcus faecium E155 using three different extraction methods: trypsin shaving, biotinylation and elution at high pH. Proteomic profiling was carried out by gel-free and gel-nanoLC-MS/MS analyses. The total proteins found with each method were 390 by the trypsin shaving, 329 by the elution at high pH, and 45 using biotinylation. An exclusively extracytoplasmic localization was predicted in 39 (10%) by trypsin shaving, in 47 (15%) by elution at high pH, and 27 (63%) by biotinylation. Comparison between the three extraction methods by Venn diagram and subcellular localization predictors (CELLO v.2.5 and Gpos-mPLoc) allowed us to identify six proteins that are most likely surface-exposed: the SCP-like extracellular protein, a low affinity penicillin-binding protein 5 (PBP5), a basic membrane lipoprotein, a peptidoglycan-binding protein LysM (LysM), a D-alanyl-D-alanine carboxypeptidase (DdcP) and the peptidyl-prolyl cis-trans isomerase (PpiC). Due to their close relationship with the peptidoglycan, we chose PBP5, LysM, DdcP and PpiC to test their potential as vaccine candidates. These putative surface-exposed proteins were overexpressed in Escherichia coli and purified. Rabbit polyclonal antibodies raised against the purified proteins were able to induce specific opsonic antibodies that mediated killing of the homologous strain E. faecium E155 as well as clinical strains E. faecium E1162, Enterococcus faecalis 12030, type 2 and type 5. Passive immunization with rabbit antibodies raised against these proteins reduced significantly the colony counts of E. faecium E155 in mice, indicating the effectiveness of these surface-related proteins as promising vaccine candidates to target different enterococcal pathogens.

Preventing the transmission of multidrug-resistant organisms: modeling the relative importance of hand hygiene and environmental cleaning interventions

OBJECTIVE

Hand hygiene and environmental cleaning are essential infection prevention strategies, but the relative impact of each is unknown. This information is important in assessing resource allocation.

METHODS

We developed an agent-based model of patient-to-patient transmission-via the hands of transiently colonized healthcare workers and incompletely terminally cleaned rooms-in a 20-patient intensive care unit. Nurses and physicians were modeled and had distinct hand hygiene compliance levels on entry and exit to patient rooms. We simulated the transmission of Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci for 1 year using data from the literature and observed data to inform model input parameters.

RESULTS

We simulated 175 parameter-based scenarios and compared the effects of hand hygiene and environmental cleaning on rates of multidrug-resistant organism acquisition. For all organisms, increases in hand hygiene compliance outperformed equal increases in thoroughness of terminal cleaning. From baseline, a 2∶1 improvement in terminal cleaning compared with hand hygiene was required to match an equal reduction in acquisition rates (eg, a 20% improvement in terminal cleaning was required to match the reduction in acquisition due to a 10% improvement in hand hygiene compliance).

CONCLUSIONS

Hand hygiene should remain a priority for infection control programs, but environmental cleaning can have significant benefit for hospitals or individual hospital units that have either high hand hygiene compliance levels or low terminal cleaning thoroughness.

Expression and functional characterization of NOD2 in decidual stromal cells isolated during the first trimester of pregnancy

NOD2, one of the cytosolic proteins that contain a nuclear oligomerization domain (NOD), is a pattern recognition receptor (PRR) involved in innate immune responses to intracellular pathogens. Little is known, however, about the effect of NOD2 expression on the maternal–fetal relationship. Our aim was to elucidate the functions of NOD2 in normal decidual stromal cells (DSCs) from the first trimester. Tissues and DSCs were isolated from 26 patients with normal pregnancies that required abortion. The expression of NOD2 in deciduas/decidual stromal cells (DSCs) was examined by real-time PCR, immunohistochemistry, and In-cell western. DSCs containing NOD2 were stimulated by its ligand, muramyl dipeptide (MDP). The secretion of various cytokines and chemokines were measured by ELISA and the apoptotic rate was determined by flow cytometry. Treatment with MDP significantly elevated the expression of both NOD2 mRNA and protein levels in DSCs. In addition, MDP activation of NOD2 significantly increased IL-1β and MCP-1 cytokine expression in a dose dependent manner but had no effect on IL-12 expression. IL-1β and TNF-α also significantly increased the expression of NOD2 in DSCs, suggesting a positive feedback loop mechanism. Moreover, MDP stimulation augmented DSC apoptosis. In summary, the results suggest that NOD2 expression in DSCs plays an important role in protecting the embryo and preventing infection in the maternal-fetal interface.

Development of a serology-based assay for efficacy evaluation of a lactococcicosis vaccine in Seriola fish

Lactococcicosis is an infection caused by the bacterium Lactococcus garvieae and creates serious economic damage to cultured marine and fresh water fish industries. The use of the assay currently applied to evaluate the potency of the lactococcicosis vaccine is contingent upon meeting specific parameters after statistical analysis of the percent survival of the vaccinated yellowtail or greater amberjack fish after challenge with a virulent strain of L. garvieae. We found that measuring the serological response with a quantitative agglutinating antibody against the L. garvieae antigen (phenotype KG+) was an effective method of monitoring the potency of lactococcicosis vaccines. Vaccinated fish had significantly higher antibody titers than control fish when the L. garvieae Lg2-S strain was used as an antigen. Furthermore, the titer of the KG + agglutinating antibody was correlated with vaccine potency, and the cut-off titer was determined by comparing the data with those from the challenge test. An advantage of the proposed serology-based potency assay is that it will contribute to reduced numbers of animal deaths during vaccine potency evaluations.

Central venous catheter-related infections in hematology and oncology: 2012 updated guidelines on diagnosis, management and prevention by the Infectious Diseases Working Party of the German Society of Hematology and Medical Oncology

BACKGROUND

Cancer patients are at increased risk for central venous catheter-related infections (CRIs). Thus, a comprehensive, practical and evidence-based guideline on CRI in patients with malignancies is warranted.

PATIENTS AND METHODS

A panel of experts by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) has developed a guideline on CRI in cancer patients. Literature searches of the PubMed, Medline and Cochrane databases were carried out and consensus discussions were held.

RESULTS

Recommendations on diagnosis, management and prevention of CRI in cancer patients are made, and the strength of the recommendation and the level of evidence are presented.

CONCLUSION

This guideline is an evidence-based approach to the diagnosis, management and prevention of CRI in cancer patients.

Prophylactic antibiotics for preventing Gram positive infections associated with long-term central venous catheters in oncology patients

BACKGROUND

This is an updated version of the review which was first published in the Cochrane Database of Systematic Reviews in 2006. Long-term central venous catheters (CVCs), including tunnelled CVCs (TCVCs) and totally implanted devices or ports (TIDs), are increasingly used when treating oncology patients. Despite international guidelines on sterile insertion and appropriate CVC maintenance and use, infection remains a common complication. These infections are mainly caused by Gram positive bacteria. Antimicrobial prevention strategies aimed at these micro-organisms could potentially decrease the majority of CVC infections. The aim of this review was to evaluate the efficacy of antibiotics in the prevention of Gram positive infections in long-term CVCs.

OBJECTIVES

To determine the efficacy of administering antibiotics prior to the insertion of long-term CVCs, or flushing or locking long-term CVCs with a combined antibiotic and heparin solution, or both, to prevent Gram positive catheter-related infections in adults and children receiving treatment for cancer.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (to June 2013) and the MEDLINE and EMBASE databases (1966 to 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing prophylactic antibiotics given prior to long-term CVC insertion with no antibiotics, RCTs comparing a combined antibiotic and heparin solution with a heparin-only solution to flush or lock newly inserted long-term CVCs, and RCTs comparing a combination of these interventions in adults and children receiving treatment for cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, classified them and extracted data on to a pre-designed data collection form. We pooled data using the RevMan software version 5.2 and used random-effects (RE) model methods for meta-analyses.

MAIN RESULTS

We included 11 trials with a total of 828 oncology patients (adults and children). We assessed most included studies to be at a low or unclear risk of bias. Five trials compared the use of antibiotics (vancomycin, teicoplanin or ceftazidime) given before the insertion of the long-term CVC with no antibiotics, and six trials compared antibiotics (vancomycin, amikacin or taurolidine) and heparin with a heparin-only solution for flushing or locking the long-term CVC after use. Administering an antibiotic prior to insertion of the CVC did not significantly reduce Gram positive catheter-related sepsis (CRS) (five trials, 360 adults; risk ratio (RR) 0.72, 95% confidence interval (CI) 0.33 to 1.58; I² = 5 2%; P = 0.41).Flushing and locking long-term CVCs with a combined antibiotic and heparin solution significantly reduced the risk of Gram positive catheter-related sepsis compared with a heparin-only solution (468 participants, mostly children; RR 0.47, 95% CI 0.28 to 0.80; I² = 0%; P = 0.005). For a baseline infection rate of 15%, this reduction translated into a number needed to treat (NNT) of 12 (95% CI 9 to 33) to prevent one catheter-related infection. We considered this evidence to be of a moderate quality.

AUTHORS' CONCLUSIONS

There was no benefit to administering antibiotics before the insertion of long-term CVCs to prevent Gram positive catheter-related infections. Flushing or locking long-term CVCs with a combined antibiotic and heparin solution appeared to reduce Gram positive catheter-related sepsis experienced in people at risk of neutropenia through chemotherapy or disease. Due to insufficient data it was not clear whether this applied equally to TCVCs and totally implanted devices (TIDs), or equally to adults and children. The use of a combined antibiotic and heparin solution may increase microbial antibiotic resistance, therefore it should be reserved for high risk people or where baseline CVC infection rates are high (> 15%). Further research is needed to identify high risk groups most likely to benefit.

Propionibacterium acnes: an underestimated pathogen in implant-associated infections

The role of Propionibacterium acnes in acne and in a wide range of inflammatory diseases is well established. However, P. acnes is also responsible for infections involving implants. Prolonged aerobic and anaerobic agar cultures for 14 days and broth cultures increase the detection rate. In this paper, we review the pathogenic role of P. acnes in implant-associated infections such as prosthetic joints, cardiac devices, breast implants, intraocular lenses, neurosurgical devices, and spine implants. The management of severe infections caused by P. acnes involves a combination of antimicrobial and surgical treatment (often removal of the device). Intravenous penicillin G and ceftriaxone are the first choice for serious infections, with vancomycin and daptomycin as alternatives, and amoxicillin, rifampicin, clindamycin, tetracycline, and levofloxacin for oral treatment. Sonication of explanted prosthetic material improves the diagnosis of implant-associated infections. Molecular methods may further increase the sensitivity of P. acnes detection. Coating of implants with antimicrobial substances could avoid or limit colonization of the surface and thereby reduce the risk of biofilm formation during severe infections. Our understanding of the role of P. acnes in human diseases will likely continue to increase as new associations and pathogenic mechanisms are discovered.

Universal glove and gown use and acquisition of antibiotic-resistant bacteria in the ICU: a randomized trial

IMPORTANCE

Antibiotic-resistant bacteria are associated with increased patient morbidity and mortality. It is unknown whether wearing gloves and gowns for all patient contact in the intensive care unit (ICU) decreases acquisition of antibiotic-resistant bacteria.

OBJECTIVE

To assess whether wearing gloves and gowns for all patient contact in the ICU decreases acquisition of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) compared with usual care.

DESIGN, SETTING, AND PARTICIPANTS

Cluster-randomized trial in 20 medical and surgical ICUs in 20 US hospitals from January 4, 2012, to October 4, 2012.

INTERVENTIONS

In the intervention ICUs, all health care workers were required to wear gloves and gowns for all patient contact and when entering any patient room.

MAIN OUTCOMES AND MEASURES

The primary outcome was acquisition of MRSA or VRE based on surveillance cultures collected on admission and discharge from the ICU. Secondary outcomes included individual VRE acquisition, MRSA acquisition, frequency of health care worker visits, hand hygiene compliance, health care–associated infections, and adverse events.

RESULTS

From the 26,180 patients included, 92,241 swabs were collected for the primary outcome. Intervention ICUs had a decrease in the primary outcome of MRSA or VRE from 21.35 acquisitions per 1000 patient-days (95% CI, 17.57 to 25.94) in the baseline period to 16.91 acquisitions per 1000 patient-days (95% CI, 14.09 to 20.28) in the study period, whereas control ICUs had a decrease in MRSA or VRE from 19.02 acquisitions per 1000 patient-days (95% CI, 14.20 to 25.49) in the baseline period to 16.29 acquisitions per 1000 patient-days (95% CI, 13.48 to 19.68) in the study period, a difference in changes that was not statistically significant (difference, −1.71 acquisitions per 1000 person-days, 95% CI, −6.15 to 2.73; P = .57). For key secondary outcomes, there was no difference in VRE acquisition with the intervention (difference,  0.89 acquisitions per 1000 person-days; 95% CI, −4.27 to 6.04, P = .70), whereas for MRSA, there were fewer acquisitions with the intervention (difference, −2.98 acquisitions per 1000 person-days; 95% CI, −5.58 to −0.38; P = .046). Universal glove and gown use also decreased health care worker room entry (4.28 vs 5.24 entries per hour, difference, −0.96; 95% CI, −1.71 to −0.21, P = .02), increased room-exit hand hygiene compliance (78.3% vs 62.9%, difference, 15.4%; 95% CI, 8.99% to 21.8%; P = .02) and had no statistically significant effect on rates of adverse events (58.7 events per 1000 patient days vs 74.4 events per 1000 patient days; difference, −15.7; 95% CI, −40.7 to 9.2, P = .24).

CONCLUSIONS AND RELEVANCE

The use of gloves and gowns for all patient contact compared with usual care among patients in medical and surgical ICUs did not result in a difference in the primary outcome of acquisition of MRSA or VRE. Although there was a lower risk of MRSA acquisition alone and no difference in adverse events, these secondary outcomes require replication before reaching definitive conclusions.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT0131821.

Modeling the regional spread and control of vancomycin-resistant enterococci

BACKGROUND

Because patients can remain colonized with vancomycin-resistant enterococci (VRE) for long periods of time, VRE may spread from one health care facility to another.

METHODS

Using the Regional Healthcare Ecosystem Analyst, an agent-based model of patient flow among all Orange County, California, hospitals and communities, we quantified the degree and speed at which changes in VRE colonization prevalence in a hospital may affect prevalence in other Orange County hospitals.

RESULTS

A sustained 10% increase in VRE colonization prevalence in any 1 hospital caused a 2.8% (none to 62%) average relative increase in VRE prevalence in all other hospitals. Effects took from 1.5 to >10 years to fully manifest. Larger hospitals tended to have greater affect on other hospitals.

CONCLUSIONS

When monitoring and controlling VRE, decision makers may want to account for regional effects. Knowing a hospital's connections with other health care facilities via patient sharing can help determine which hospitals to include in a surveillance or control program.

Effectiveness of a bundled intervention of decolonization and prophylaxis to decrease Gram positive surgical site infections after cardiac or orthopedic surgery: systematic review and meta-analysis

OBJECTIVE

To evaluate studies assessing the effectiveness of a bundle of nasal decolonization and glycopeptide prophylaxis for preventing surgical site infections caused by Gram positive bacteria among patients undergoing cardiac operations or total joint replacement procedures.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed (1995 to 2011), the Cochrane database of systematic reviews, CINAHL, Embase, and clinicaltrials.gov were searched to identify relevant studies. Pertinent journals and conference abstracts were hand searched. Study authors were contacted if more data were needed.

ELIGIBILITY CRITERIA

Randomized controlled trials, quasi-experimental studies, and cohort studies that assessed nasal decolonization or glycopeptide prophylaxis, or both, for preventing Gram positive surgical site infections compared with standard care.

PARTICIPANTS

Patients undergoing cardiac operations or total joint replacement procedures. DATA EXTRACTION AND STUDY APPRAISAL: Two authors independently extracted data from each paper and a random effects model was used to obtain summary estimates. Risk of bias was assessed using the Downs and Black or the Cochrane scales. Heterogeneity was assessed using the Cochran Q and I(2) statistics.

RESULTS

39 studies were included. Pooled effects of 17 studies showed that nasal decolonization had a significantly protective effect against surgical site infections associated with Staphylococcus aureus (pooled relative risk 0.39, 95% confidence interval 0.31 to 0.50) when all patients underwent decolonization (0.40, 0.29 to 0.55) and when only S aureus carriers underwent decolonization (0.36, 0.22 to 0.57). Pooled effects of 15 prophylaxis studies showed that glycopeptide prophylaxis was significantly protective against surgical site infections related to methicillin (meticillin) resistant S aureus (MRSA) compared with prophylaxis using β lactam antibiotics (0.40, 0.20 to 0.80), and a non-significant risk factor for methicillin susceptible S aureus infections (1.47, 0.91 to 2.38). Seven studies assessed a bundle including decolonization and glycopeptide prophylaxis for only patients colonized with MRSA and found a significantly protective effect against surgical site infections with Gram positive bacteria (0.41, 0.30 to 0.56).

CONCLUSIONS

Surgical programs that implement a bundled intervention including both nasal decolonization and glycopeptide prophylaxis for MRSA carriers may decrease rates of surgical site infections caused by S aureus or other Gram positive bacteria.

[Control of an outbreak of vancomycin-resistant enterococci in several hospitals of western Switzerland]

An outbreak of vancomycin-resistant enterococci (VRE) occurred in 2011 in several hospitals of western Switzerland. Given that VRE can spread rapidly within hospitals and due to the potential transfer of resistance genes to other nosocomial pathogens like MRSA, stringent control measures were implemented. Excellent coordination of control measures between partner healthcare settings was successful in stopping the outbreak.

Predictors of quantitative microbiological analysis of spatter and aerosolization during scaling

The aim of this study is to analyze the infection risk through spatter and aerosolization during scaling and to create a prediction model of the total number of hemolytic bacteria.

MATERIAL AND METHODS

Air samples were collected prior to patient's arrival and spatter and aerosol samples were collected during scaling procedure in 80 patients of 4 different dental clinics. The dentists calculated DI, CI, DMFT. Only patients with CI > = 1 were included. The bacteriological results (CFU/m3) were correlated with clinical indicators. Patients were divided into 2 groups: one that rinse with sterile water and the other with chlohexidine mouth rinse 0.1%.

RESULTS AND CONCLUSIONS

Medium size effect positive correlations were found between the number of decayed teeth and the total number of bacteria and the total number of hemolytic bacteria that grew on plate attached to the dentist's mask. The mean number of bacteria and the mean number of hemolytic bacteria that grew on plate attached to the dentist's mask were significantly lower in the group that rinse with chlorhexidine 0.1%, when compared to the group that rinsed with sterile water. When controlling for the total number of bacteria and the total number of hemolytic bacteria from air sampling, the total number of hemolytic bacteria that grew on the plate attached to the dentist's mask can be predicted by CI, group membership and DMFT score.

Effect of daily chlorhexidine bathing on hospital-acquired infection

BACKGROUND

Results of previous single-center, observational studies suggest that daily bathing of patients with chlorhexidine may prevent hospital-acquired bloodstream infections and the acquisition of multidrug-resistant organisms (MDROs).

METHODS

We conducted a multicenter, cluster-randomized, nonblinded crossover trial to evaluate the effect of daily bathing with chlorhexidine-impregnated washcloths on the acquisition of MDROs and the incidence of hospital-acquired bloodstream infections. Nine intensive care and bone marrow transplantation units in six hospitals were randomly assigned to bathe patients either with no-rinse 2% chlorhexidine-impregnated washcloths or with nonantimicrobial washcloths for a 6-month period, exchanged for the alternate product during the subsequent 6 months. The incidence rates of acquisition of MDROs and the rates of hospital-acquired bloodstream infections were compared between the two periods by means of Poisson regression analysis.

RESULTS

A total of 7727 patients were enrolled during the study. The overall rate of MDRO acquisition was 5.10 cases per 1000 patient-days with chlorhexidine bathing versus 6.60 cases per 1000 patient-days with nonantimicrobial washcloths (P=0.03), the equivalent of a 23% lower rate with chlorhexidine bathing. The overall rate of hospital-acquired bloodstream infections was 4.78 cases per 1000 patient-days with chlorhexidine bathing versus 6.60 cases per 1000 patient-days with nonantimicrobial washcloths (P=0.007), a 28% lower rate with chlorhexidine-impregnated washcloths. No serious skin reactions were noted during either study period.

CONCLUSIONS

Daily bathing with chlorhexidine-impregnated washcloths significantly reduced the risks of acquisition of MDROs and development of hospital-acquired bloodstream infections. (Funded by the Centers for Disease Control and Prevention and Sage Products; ClinicalTrials.gov number, NCT00502476.).

Construction and comparative study of monovalent and multivalent DNA vaccines against Streptococcus iniae

Streptococcus iniae is an important fish pathogen with a broad host range that includes both marine and freshwater fish species. With an aim to develop effective vaccines against S. iniae, we in this study constructed three monovalent DNA vaccines, i.e., pSagF, pSagG, and pSagI, based on sagF, G, and I, which are components of the streptolysin S cluster. The immunoprotective potentials of these vaccines were examined in a model of Japanese flounder (Paralichthys olivaceus). The results showed that following intramuscular administration, the vaccine plasmids were transported to spleen, kidney, and liver, where the vaccine-encoding transgenes were expressed. Immunocolloidal gold electron microscopy detected production of the vaccine protein in fish vaccinated with each of the vaccine plasmids. Following lethal-dose S. iniae challenge, pSagF-, pSagG-, and pSagI-vaccinated fish exhibited relative percent of survival (RPS) rates of 78%, 65%, and 76% respectively. To examine whether multivalent vaccines composed of different combinations of monovalent vaccines would produce better protections, flounder were vaccinated with FG (pSagF plus pSagG), FI (pSagF plus pSagG), or FGI (pSagF plus pSagG and pSagI). Subsequent challenging study showed that the RPS rates of the fish vaccinated with the divalent and trivalent vaccines were 4%-17% and 13%-26% respectively higher than those of the fish vaccinated with the component monovalent vaccines. Furthermore, FGI exhibited a strong cross protection against both serotype I and serotype II S. iniae, apparently due to, as revealed by sequence analysis, the existence of highly conserved SagF, SagG, and SagI homologs in these serotypes. Immunological analysis showed that all vaccines induced (i) specific serum antibody production, (ii) enhanced complement-mediated bactericidal activity, and (iii) significant induction of a wide range of immune genes. However, the levels of gene expression and serum bactericidal activity induced by FGI were in general more potent than those induced by monovalent vaccines. Taken together, these results indicate that the DNA vaccines based on sagF, G, and I, especially when they are formulated as multivalent vaccines, are highly efficacious against S. iniae infection.

Effect of vaccines on bacterial meningitis worldwide

Three bacteria--Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis--account for most acute bacterial meningitis. Measurement of the effect of protein-polysaccharide conjugate vaccines is most reliable for H influenzae meningitis because one serotype and one age group account for more than 90% of cases and the incidence has been best measured in high-income countries where these vaccines have been used longest. Pneumococcal and meningococcal meningitis are caused by diverse serotypes and have a wide age distribution; measurement of their incidence is complicated by epidemics and scarcity of surveillance, especially in low-income countries. Near elimination of H influenzae meningitis has been documented after vaccine introduction. Despite greater than 90% reductions in disease attributable to vaccine serotypes, all-age pneumococcal meningitis has decreased by around 25%, with little data from low-income settings. Near elimination of serogroup C meningococcal meningitis has been documented in several high-income countries, boding well for the effect of a new serogroup A meningococcal conjugate vaccine in the African meningitis belt.

Choosing optimal antimicrobial therapies

Life-threatening infectious disease emergencies require immediate, aggressive parenteral administration of antimicrobial agents to ensure high bactericidal concentrations of drug at the site of infection. Usually initial treatment is empiric until culture results and antimicrobial sensitivities are reported. This approach necessitates the use of broad-spectrum bactericidal agents that will eradicate the presumed infecting organism(s), which potentially could be multidrug resistant. For infections potentially attributable to gram-positive bacteria, vancomycin is commonly used because it will be effective for highly resistant strains such as MRSA and multidrug-resistant S pneumoniae. For gram-negative infections, broad-spectrum β-lactams, such as ceftriaxone, piperacillin-tazobactam, and the carbapenems, are commonly chosen. Excellent alternatives include the fluoroquinolone antibiotics. For nosocomial infections whereby P aeruginosa and other highly resistant organisms may be the cause, antipseudomonal β-lactams such as cefepime, ceftazidime, piperacillin-tazobactam, or doripenem may be used as well as the fluoroquinolone, ciprofloxacin. For anaerobic infections, it is usually necessary to add either metronidazole or clindamycin. Once an infection is under control and the culture and sensitivity results are reported, it is important to switch to the most narrow-spectrum agent possible. Taking this action will decrease the potential for adverse drug effects and the risk of development of antibiotic-induced resistance.