Managing methicillin-resistant staphylococci: a paradigm for preventing nosocomial transmission of resistant organisms

Screening for multi-drug-resistant Gram-negative bacteria: what is effective and justifiable?

Effectiveness is a key criterion in assessing the justification of antibiotic resistance interventions. Depending on an intervention’s effectiveness, burdens and costs will be more or less justified, which is especially important for large scale population-level interventions with high running costs and pronounced risks to individuals in terms of wellbeing, integrity and autonomy. In this paper, we assess the case of routine hospital screening for multi-drug-resistant Gram-negative bacteria (MDRGN) from this perspective. Utilizing a comparison to screening programs for Methicillin-Resistant Staphylococcus aureus (MRSA) we argue that current screening programmes for MDRGN in low endemic settings should be reconsidered, as its effectiveness is in doubt, while general downsides to screening programs remain. To accomplish justifiable antibiotic stewardship, MDRGN screening should not be viewed as a separate measure, but rather as part of a comprehensive approach. The program should be redesigned to focus on those at risk of developing symptomatic infections with MDRGN rather than merely detecting those colonised.

Nasal Carriage and Methicillin Resistance of Staphylococcus aureus among Schoolchildren in Sana'a City, Yemen

Background

Staphylococcus aureus (S. aureus) is a frequent cause of serious health problems with high morbidity and mortality. The risk of S. aureus infections is increased with the emergence of methicillin-resistant S. aureus (MRSA). This study aims to determine the nasal carriage rate of both S. aureus and MRSA among schoolchildren in Sana'a city.

Methods

This is a cross-sectional study conducted from January 2018 to May 2020. Five hundred and thirty-six students were enrolled. Their age ranged from 5 to 19 years with the mean age and standard deviation equal to 13.3 ± 3.5 years. Nasal swabs were collected from each student for culturing and methicillin susceptibility testing.

Results

Students with positive culture were 271 (51%) males and 265 (49%) females. S. aureus was isolated from 129 (24%) students whereas the overall prevalence of MRSA was 8 (1.5%). S. aureus was significantly recovered from students at the age group of 10–14 years (χ² = 7.02; p=0.03), females than males (OR = 1.96; χ² = 10.75; p=0.001), and students who were admitted into hospitals (OR = 1.6; χ² = 4.89; p=0.03). Nevertheless, there were no significant differences between MRSA carriage and students' age (χ² = 2.3; p=0.32), gender (OR = 1.02; χ² = 0.001; p=0.63), and hospital admission (OR = 1.4; χ² = 0.25; p=0.62).

Conclusions

The prevalence of MRSA is low among schoolchildren in Sana'a city. Age, gender, and previous hospital admission were statistically associated with nasal carriage of S. aureus but not MRSA nasal carriage.

Bacterial growth and recovery on hospital biometric devices: effect of two types of disinfectants

Objectives:

The aim of the study was to evaluate the presence of bacterial contamination on biometric identification devices in a public hospital; identify the species of bacteria implicated in the contamination and assess bacterial recovery after the use of 2 types of disinfectants: alcohol 70% and isopropyl alcohol chlorhexidine.

Design:

Before and after trial.

Setting:

Public hospital, tertiary referral center.

Participants:

All existing biometric identification devices in the hospital (n = 20).

Methods:

Collection of 2 microbiological samples from the fingerprint reading surface of biometric devices immediately before and after applying the solution with alcohol 70% and in separate time periods with isopropyl alcohol chlorhexidine.

Results:

It have been identified 21 different bacterial species in a total of 78 samples, mostly Staphylococcus epidermidis (32 samples) and S aureus (7 samples). S epidermidis was eliminated in 61.5% of the samples after disinfecting with alcohol 70% and in 92.3% of the samples disinfected with isopropyl alcohol chlorhexidine. S aureus was eliminated in 33.3% and 100% of the samples, respectively. We found no bacterial growth in 10% of the devices after disinfection with 70% alcohol and in 78.9% of devices after disinfection with isopropyl alcohol chlorhexidine. We also found that there was a decrease in the frequency of species isolated after using both disinfection solutions, although isopropyl alcohol chlorhexidine appeared to be more effective.

Conclusions:

The biometric identification devices used in this hospital seem to be safe regardless of the products used for its cleaning. The majority of the bacteria found are commensal skin microorganisms. We did not find pathogenic bacteria for immunocompetent individuals, in particular methicillin-resistant S aureus.

Multidrug-Resistant Organisms in Palliative Care: A Systematic Review

Background: Multidrug-resistant organisms (MDROs) are an important health care issue. Patients in Western societies often present an increased morbidity of chronic conditions accompanied by poor immune status and the use of devices. In particular, patients in palliative care (PC) are at greater risk of MDRO colonization, due to accompanying special devices and being hospitalized. Objective: To gain an overview of the literature regarding MDROs in PC. Design: Systematic review Data sources: On the 19th of October 2019 the databases " PubMed" and " CINAHL" were used to identify studies reporting on MDROs in PC; the search was updated on 16th of May 2020. Results: Seventeen out of 486 articles were included. Six represent qualitative data, 10 quantitative data, and one a mixed methods approach. Prevalence data range from 4.0% to 18%. MDRO colonization has a negative impact on patients and families. It leads to uncertainties and higher workload by staff members. Strategies for the management of MDROs in the field of PC are predominantly available for methicillin-resistant Staphylococcus aureus. Not even half of institutions utilize existing protocols. Recommendations for dealing with MDROs indicate required staff and time resources as well as information, communication, and specific knowledge. Conclusion: There is a great need for studies examining the prevalence of all MDROs in the PC setting. Additionally, not only patients but also a public enlightenment on MDROs should be provided to decrease knowledge gaps and therefore reduce transmission on MDROs.

Strategies to Prevent Healthcare-Associated Infections: A Narrative Overview

Healthcare-associated infections (HCAIs) are a major source of morbidity and mortality and are the second most prevalent cause of death. Furthermore, it has been reported that for every one-hundred patients admitted to hospital, seven patients in high-income economies and ten in emerging and low-income economies acquire at least one type of HCAI. Currently, almost all pathogenic microorganisms have developed antimicrobial resistance, and few new antimicrobials are being developed and brought to market. The literature search for this narrative review was performed by searching bibliographic databases (including Google Scholar and PubMed) using the search terms: "Strategies," "Prevention," and "Healthcare-Associated Infections," followed by snowballing references cited by critical articles. We found that although hand hygiene is a centuries-old concept, it is still the primary strategy used around the world to prevent HCAIs. It forms one of a bundle of approaches used to clean and maintain a safe hospital environment and to stop the transmission of contagious and infectious microorganisms, including multidrug-resistant microbes. Finally, antibiotic stewardship also has a crucial role in reducing the impact of HCAIs through conserving currently available antimicrobials.

Co0 superparamagnetic nanoparticles stabilized by an organic layer coating with antimicrobial activity

Cobalt (Co) is one of the most promising materials in nanotechnology due to its superior magnetic properties. However, due to the high cytotoxicity of cobalt, the activity in biological systems has been little studied. In this work, we report the structural, morphological, and magnetic properties of cobalt nanoparticles stabilized with an organic layer (Co⁰@C-NPs) and its potential antimicrobial activity. The Co⁰@C-NPs were obtained from solvothermal conditions and characterized by X-ray powder diffraction, electronic microscopy, and magnetic measurements. The organic layer was analysed by thermogravimetric analysis, Scanning Electron Microscopy, Energy Dispersive Spectrometer, and Fourier Transform Infrared Spectroscopy. From the TEM image, an organic coating layer is observed around Co⁰ where this coating prevents NPs from oxidation allowing it to remain stable until 400 °C. Surface composition studies by SEM/EDS allowed the identification of carbon, oxygen, and cobalt elements present in the organic layer. This result was corroborated later by FITR analysis. Preliminary antibacterial properties were also investigated, which showed that the cobalt nanoparticles are active against Staphylococcus aureus after 1 h of exposure. The superparamagnetic properties and organic coating Co⁰@C-NPs could be biocompatible with biological systems, but more research is needed to apply these nanoparticles in biomedical products.

The Co⁰@C-NPs were obtained using solvothermal synthesis. The Co⁰@C-NPs were characterized by different techniques and its antimicrobial activity was assessed against Staphylococcus aureus by microdilution assay and scanning electron microscope.

Bactericidal effects of metallosurfactants based cobalt oxide/hydroxide nanoparticles against Staphylococcus aureus

This work deals with the fabrication of metallosurfactants derived cobalt oxide and hydroxide nanosuspensions (Ns) by microemulsion method and their antimicrobial, cytotoxic, genotoxic, antioxidant and cytostatic activity have been investigated. The methodology used is environmentally compliant as no external reducing agent was used. Three metallosurfactants i.e. CoCTAC (Bishexadecyltrimethylammonium cobalt tetrachloride), CoDDA (Bisdodecylamine cobalt dichloride) and CoHEXA (bishexadecylamine cobalt dichloride) were used. Co-metallosurfactants were synthesized, characterized and were utilized for the preparation of mixed microemulsion to yield nanosuspensions. Nanoparticles prepared were characterized using Transmission electron microscopy (TEM), Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), UV-vis spectroscopy and Zeta potential. The nanoparticles were found to be spherical, with size range 1-5 nm, for all the three precursors. Further, their cytotoxicity, genotoxicity, and antimicrobial activity were investigated against Staphylococcus aureus (S. aureus). To evaluate these activities, techniques such as gram staining method, agar well diffusion, and colony forming unit count (CFU) were utilized. From all these experiments it was confirmed that CoCTAC Ns has maximum antimicrobial activity against multiple medicine resistant S. aureus. Circular dichroism and gel electrophoresis also validated the vigorous genotoxic effect of CoCTAC Ns. The antimicrobial activity trend investigated from CFU experiment was CoCTAC Ns (2 × 10⁵ CFU/mL) > CoDDA Ns (17 × 10⁵ CFU/mL) > CoHEXA Ns (46.5 × 10⁵ CFU/mL). FESEM authenticated the effect of Co Ns on the morphology of S. aureus. Cell shrinkage, formation of holes, change of morphology, and cell wall rupturing was observed for all three cases but most significant antibacterial activity was noted for the case of CoCTAC Ns. In addition, antiproliferative activity was also examined against HepG2 cells (human liver cancer cell line) and HEK293 cells (human embryonic kidney cell line). After 70% confluency of cells, cobalt oxide/hydroxide Ns were added by diluting the nanosuspension in 0.2, 0.4, 0.5, and 0.8% V/V ratio to check the cell viability.

MRSA diversity and the emergence of LA-MRSA in a large teaching hospital in Slovenia

The methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of a variety of infections in hospitals and the community. One of the most prominent changes in the MRSA epidemiology is the emergence of livestock-associated MRSA (LA-MRSA) strains in the human population. The aim of this study was to follow the MRSA epidemiology in a large teaching hospital during an 8-year time period (2006-2013). Altogether 519 MRSA, cultured from screening or clinical samples, were distributed into 77 spa types, of which three (t003 and t001, associated with CC5; and t015; associated with CC45) were the most common. LA-MRSA-associated spa types (t011, t034, t108, t899; associated with CC398) started to emerge in the year 2009 and continued to be found annually at a frequency from 3.9% to 12.7% of all MRSA strains examined. Only 6 of 27 LA-MRSA strains were associated with infections.

Development and evaluation of the automated risk assessment system for multidrug-resistant organisms (autoRAS-MDRO)

BACKGROUND

A high proportion of infections acquired in hospitals are caused by multidrug-resistant organisms (MDROs). The priority in MDRO prevention is to detect high-risk patients and implement preventive intervention as soon as possible.

AIM

To develop an automated risk assessment system for MDROs (autoRAS-MDRO) to screen for patients at MDRO infection risk and evaluate the predictive validity of the autoRAS-MDRO.

METHODS

Data for 4200 variables were extracted from the electronic health records (EHRs) for constructing the MDRO risk-scoring algorithm, which was based on a logistic regression model. The autoRAS-MDRO was designed such that the MDRO risk classification (high, moderate, low risk) could be automatically displayed on the nursing Kardex screen in the EHRs system. For the development of the MDRO risk-scoring algorithm, 1000 patients with MDROs and 4000 patients without MDROs were selected; similarly, for the evaluation, 2173 and 8692 patients with and without MDROs, respectively, were selected.

FINDINGS

The predictive validity of the autoRAS-MDRO was as follows: (i) at the 6-month evaluation: sensitivity, 81%; specificity, 79%; positive predictive value (PPV), 49%; negative predictive value (NPV), 94%; and Youden index, 0.60; (ii) at the 12-month evaluation: sensitivity 79%, specificity 78%, PPV 47%, NPV 94%, and Youden index, 0.57.

CONCLUSION

The autoRAS-MDRO had moderate predictive validity. It could be useful in redirecting nurses' time and efforts required for MDRO risk assessment and implementation of infection control measures, and in reducing the incidence of MDRO infection in hospitals, thereby contributing to patient safety.

MRSA Prevalence and Associated Risk Factors among Health-Care Workers in Non-outbreak Situations in the Dutch-German EUREGIO

Preventing the spread of methicillin-resistant Staphylococcus aureus (MRSA) in healthcare facilities is a major infection control target. However, only a few studies have assessed the potential role of healthcare workers (HCWs) for MRSA dissemination. To investigate the MRSA prevalence and the risk factors for MRSA colonization among HCWs, nasopharyngeal swabs were taken between June 2010 and January 2011 from 726 employees from nine acute care hospitals with different care levels within the German part of a Dutch-German border region (EUREGIO). The isolated MRSA strains were investigated using spa typing. The overall MRSA prevalence among HCWs in a non-outbreak situation was 4.6% (33 of 726), and was higher in nurses (5.6%, 29 of 514) than in physicians (1.2%, 1 of 83). Possible risk factors associated with MRSA colonization were a known history of MRSA carriage and the presence of acne. Intensive contact with patients may facilitate MRSA transmission between patients and HCWs. Furthermore, an accumulation of risk factors was accompanied by an increased MRSA prevalence in HCW.

Successful reduction of hospital-acquired methicillin-resistant Staphylococcus aureus in a urology ward: a 10-year study

BACKGROUND

To eradicate hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) using a stepwise infection control strategy that includes an avoidance of antimicrobial prophylaxis (AMP) based on surgical wound classification and an improvement in operative procedures in gasless single-port urologic surgery.

METHODS

The study was conducted at an 801-bed university hospital. Since 2001, in the urology ward, we have introduced the stepwise infection control strategy. In 2007, surveillance cultures for MRSA in all urological patients were commenced. The annual incidence of MRSA was calculated as a total number of newly identified MRSA cases per 1,000 patient days. Trend analysis was performed using a Poisson regression.

RESULTS

Over the study period, 139,866 patients, including 10,201 urology patients, were admitted to our hospital. Of these patients, 3,719 patients, including 134 ones in the urology ward, were diagnosed with MRSA throughout the entire hospital. Although the incidence of MRSA increased throughout the entire hospital (p = 0.002), it decreased significantly in the urology ward (p < 0.0001). Of the 134 cases, 45 (33.6%) were classified as "imported," and 89 (66.4%) as "acquired." In the urology ward, the incidence of acquired MRSA decreased significantly over time (p < 0.0001), whereas the incidence of imported MRSA did not change over time (p = 0.66). A significant decrease (p < 0.0001) in the incidence of clinically significant MRSA infection over time was found.

CONCLUSIONS

Stepwise infection control strategy that includes a reduction or avoidance of antimicrobial prophylaxis in minimally invasive surgery can contribute to a reduction in hospital-acquired MRSA.

TRIAL REGISTRATION

Current study has approved by the institutional ethical review board (No.1141).

Severe methicillin-susceptible Staphylococcus aureus infections associated with epidural injections at an outpatient pain clinic

BACKGROUND

Recent outbreaks in ambulatory care settings have highlighted infection control breaches as risk factors for disease transmission. In May 2009, 3 patients were hospitalized with severe methicillin-susceptible Staphylococcus aureus (MSSA) infections after receiving epidural injections at a West Virginia outpatient pain clinic.

METHODS

We conducted a retrospective cohort study evaluating clinic patients who received injections during a 3-week period. A case was defined as laboratory-confirmed infection or clinical evidence of infection ≤ 14 days after a patient received an injection. Infection control procedures were assessed. MSSA isolates from patient infections and clinic staff nasal swabs were genotyped by using pulsed-field gel electrophoresis.

RESULTS

Eight (7%) of 110 cohort patients met the case definition; 6 (75%) cases were laboratory confirmed. Eight (12%) of 69 patients who received epidural injections were case patients compared with none of the other 41 patients (P = .02). During procedures, staff use of face masks and preparation of patient skin were suboptimal; epidural injection syringes were reused to access shared medication vials. MSSA isolates from 2 patients and 1 staff member were indistinguishable by pulsed-field gel electrophoresis.

CONCLUSION

Infection control breaches likely facilitated MSSA transmission to patients receiving epidural injections. Adhering to correct infection control practices in ambulatory care settings is critical to prevent disease transmission.

Methicillin-resistant Staphylococcus aureus: prevalence and current susceptibility pattern in sikkim

Background:

Prevalence of methicillin-resistant Staphylococcus Aureus (MRSA) strains is reported to be increasing globally.

Objectives:

The study was conducted to find the magnitude and antibiotic susceptibility pattern of MRSA infection in a referral tertiary care teaching hospital of Sikkim, India.

Materials and Methods:

In this cross sectional study, 827 clinical specimens were collected from different departments of Central Referral Hospital. One hundred and ninety-six carrier screening nasal swabs were obtained from health care workers of the hospital. Subsequently, the antimicrobial susceptibility test was performed for the confirmed MRSA isolates as per Clinical and Laboratory Standards Institute (CLSI).

Results:

Methicillin resistance was seen in 152 isolates of S. aureus – 111 from clinical specimens and 41 from carrier screening samples. MRSA positivity among males was significantly higher than females. Extremely significant MRSA-positive cases were observed from ages less than 30 years, in-patient cases, particularly with a stay of more than 15 days and with a previous history of intake of broad spectrum antibiotics. Incidentally, there was no significant difference of MRSA positivity with a previous history of hospitalization. The extent of MRSA and drug resistance pattern was significantly different among various samples of S. aureus-positive isolates. The strains tested exhibited decreased susceptibility to vancomycin and imipenem. Most vulnerable of the carrier were the cleaners, that was a significant observation. Incidentally, there was no resistance in the carriers to both vancomycin and imipenem.

Conclusion:

MRSA is prevalent in our hospital and strains resistant to methicillin and vancomycin were quite high.

Contribution of microbiology to an effective control of healthcare-associated infections

An effective control of healthcare-associated infections is not realized without an intensive participation of microbiologic activities. Authors present the model of a centre for healthcare-associated infection control established in 2008 at Semmelweis University. The new model of the surveillance system is based on diagnostic and experimental microbiologic data. Clinical and epidemiological microbiologic examinations are performed in the same laboratory using identical methods, and the results are continually compared. Reports consist of two functional parts; namely list of pathogens isolated and antibiotic sensitivity patterns for clinicians and messages especially for epidemiologists including abbreviated information on bacteria of nosocomial importance. Rapid detection of the most important pathogens both from clinical samples and from those obtained for detecting nasal carriage is carried out by a sensitive and specific method of an automated real time PCR. Biotyping of isolates by detailed biochemical substrate spectrum, genotyping by ready-to-use kits depending on polymorphism of repetitive DNA sequences, and cluster analysis of data are used for up-to-date survey of nosocomial situation. Statistical analysis of reports is performed by the multifactorial software OSIRIS Epidemiology. Orv. Hetil., 2011, 152, 437–442.

[Contact precautions in intensive care units: facilitating and inhibiting factors for professionals' adherence]

The objective of this study was to identify facilitating and limiting factors for professionals' compliance with contact precautions in an intensive care unit of a general hospital. This cross-sectional study was performed from May to October 2007, using a semi-structured questionnaire for data collection. Participants were 102 professionals, as follows: nursing technician (54.9%), nurse (12.7%), preceptor physician (10.8%), apprentice physiotherapist (8.8%), preceptor physiotherapist (7.8%) and resident physician (4.9%). The limiting factors for compliance with hand cleansing were forgetting, lack of knowledge, distance from sink, skin irritation, and lack of materials. The use of scrubs presented the most difficulty (45%) because they were not available at the shower box, were inappropriately stored, and due to the heat and collective use. Glove use was the practice most easily conducted in everyday practice. Results show the need to implement precaution measures to minimize the dissemination of resistant microorganisms.

Model or meal? Farm animal populations as models for infectious diseases of humans

In recent decades, theory addressing the processes that underlie the dynamics of infectious diseases has progressed considerably. Unfortunately, the availability of empirical data to evaluate these theories has not grown at the same pace. Although laboratory animals have been widely used as models at the organism level, they have been less appropriate for addressing issues at the population level. However, farm animal populations can provide empirical models to study infectious diseases at the population level.

Peripatetic health-care workers as potential superspreaders

Many nosocomial outbreaks exhibit "superspreading events" in which cross-transmission occurs via a single individual to a large number of patients. We investigated how heterogeneity in Health-Care Worker (HCW) behaviors, especially compliance to hand hygiene, may cause superspreading events. In particular, we compared the superspreading potential of peripatetic (noncohorted) HCWs with that of other HCWs. We developed an agent-based model for hand transmission of a pathogen in a hospital ward. Three HCW profiles were allowed: 2 assigned profiles, one with frequent contacts with a limited number of patients, another with fewer contacts but with more patients; and one peripatetic profile, with a single daily contact with all patients. We used data from the literature on common nosocomial pathogens (Staphylococcus aureus, Enterococci). The average number of patients colonized over 1 month increases with noncompliance to hand hygiene. Importantly, we show that this increase depends on the profile of noncompliant HCWs; for instance, it remains low for a single noncompliant assigned HCW but can be quite large for a single noncompliant peripatetic HCW. Outbreaks with this single fully noncompliant peripatetic HCW (representing only 4.5% of the staff) are similar to those predicted when all HCWs are noncompliant following 23% of patient contacts. Noncompliant peripatetic HCWs may play a disproportionate role in disseminating pathogens in a hospital ward. Their unique profile makes them potential superspreaders. This suggests that average compliance to hygiene may not be a good indicator of nosocomial risk in real life health care settings with several HCW profiles.

Methicillin-Resistant Staphylococcus aureus in a Trauma Population: Does Colonization Predict Infection?

Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly responsible for infections in hospitalized patients. Patients colonized with MRSA appear to be at higher risk for subsequent MRSA infections than those who are not colonized. In this study, we determined MRSA colonization status of trauma patients at hospital admission and compared the incidence of subsequent MRSA infections between MRSA colonized and noncolonized patients. Collected data were entered into databases at a single, Level I trauma center over a 13-month period. Three hundred fifty-five adult trauma patients were screened for MRSA on admission to the trauma intensive care unit. The patients were categorized into two groups, those colonized with MRSA at admission and those who were not. Thirty-six of 355 patients (10.1%) were colonized. Of the 319 patients not colonized, 21 (6.6%) developed MRSA infections. Twelve of 36 (33.3%) colonized patients developed MRSA infections ( P < 0.001). No differences in types of MRSA infections were found between the two groups. Colonized patients who developed MRSA infections had higher death rates, 22.2 versus 5.0 per cent ( P < 0.001). Patients colonized with MRSA on admission may be at higher risk for developing MRSA infections during hospitalization. MRSA screening protocols should be used to identify these at-risk patients.

Drug interactions modulate the potential for evolution of resistance

Antimicrobial treatments increasingly rely on multidrug combinations, in part because of the emergence and spread of antibiotic resistance. The continued effectiveness of combination treatments depends crucially on the frequency with which multidrug resistance arises. Yet, it is unknown how this propensity for resistance depends on cross-resistance and on epistatic interactions-ranging from synergy to antagonism-between the drugs. Here, we analyzed how interactions between pairs of drugs affect the spontaneous emergence of resistance in the medically important pathogen Staphylococcus aureus. Resistance is selected for within a window of drug concentrations high enough to inhibit wild-type growth but low enough for some resistant mutants to grow. Introducing an experimental method for high-throughput colony imaging, we counted resistant colonies arising across a two-dimensional matrix of drug concentrations for each of three drug pairs. Our data show that these different drug combinations have significantly different impacts on the size of the window of drug concentrations where resistance is selected for. We framed these results in a mathematical model in which the frequencies of resistance to single drugs, cross-resistance, and epistasis combine to determine the propensity for multidrug resistance. The theory suggests that drug pairs which interact synergistically, preferred for their immediate efficacy, may in fact favor the future evolution of resistance. This framework reveals the central role of drug epistasis in the evolution of resistance and points to new strategies for combating the emergence of drug-resistant bacteria.

Community-associated methicillin-resistant Staphylococcus aureus

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has emerged over the last decade across the United States and the world, becoming a major pathogen in many types of community-acquired infections. Although most commonly associated with minor skin and soft tissue infections, such as furuncles, CA-MRSA also can cause necrotizing fasciitis, pyomyositis, osteoarticular infections, and community-acquired pneumonia. This article discusses the epidemiology, diagnosis, and management of these infections from the perspective of the emergency physician.

Improving antibiotic utilization among hospitalists: a pilot academic detailing project with a public health approach

BACKGROUND

Inappropriate use of antibiotics is a major clinical problem and public health concern. We developed and implemented a pilot hospitalist-delivered academic detailing intervention to improve the patterns of antibiotic prescribing for inpatients.

OBJECTIVE

To improve antibiotic prescribing patterns on the hospitalist service of an academic medical center.

DESIGN, SETTING, AND PARTICIPANTS

Hospitalist practitioners were recruited to participate in this pre- and postintervention pilot study at Johns Hopkins Bayview Medical Center (JHBMC). Public health principles for creating a conceptual framework based on behavioral change theory were used in developing the intervention.

METHODS

Antibiotic prescribing patterns of 17 hospitalist practitioners were retrospectively reviewed. Antimicrobial prescriptions were classified as appropriate, effective but inappropriate, or inappropriate. A profile was assembled for each hospitalist, and an academic detailing intervention session was arranged. The session reviewed inappropriate prescribing practices as well as current practice guidelines. After the detailing meeting, the prescribing patterns of the hospitalists were followed prospectively.

MAIN OUTCOME MEASURES

The main outcome measures were the proportions of antibiotics prescribed inappropriately before the intervention, during the detailing period, and after the intervention.

RESULTS

Seventeen hospitalist practitioners who participated in the study. A total of 247 prescriptions were reviewed in the preintervention and 129 prescriptions in the postintervention period. Prior to academic detailing, 43% (95% CI 37%-49%) of the prescriptions were appropriate and 57% (95% CI 51%-63%) were inappropriate. After the intervention, 74% (95% CI 65%-81%) of the prescriptions were appropriate and 26% (95% CI 19%-35%) were inappropriate; P < .0001.

CONCLUSIONS

A carefully planned and methodically executed intervention can result in behavior change, even among busy hospitalists. The academic detailing intervention, which included a practice-based learning component, improved antibiotic prescribing practices of hospitalists at JHBMC.

Antimicrobial resistance prevention initiative--an update: proceedings of an expert panel on resistance

Antimicrobial resistance is a growing problem that complicates the treatment of important nosocomial and community-acquired infections. It is a worldwide problem that spans the range of human pathogens, including bacteria, fungi, and viruses. This update from the Antimicrobial Resistance Prevention Initiative (ARPI) provides a review of some important trends in antibiotic, antifungal, and antiviral resistance. Areas of focus include multidrug-resistant bacteria in the hospital setting; the growing problem of community-acquired methicillin-resistant Staphylococcus aureus; triazole and polyene resistance in nosocomial infections caused by non-Candida albicans or Aspergillus species, and the utility of in vitro susceptibility testing for these fungal infections; antiviral resistance in alpha- or beta-herpesviruses causing genital herpes or cytomegalovirus infection in immunocompromised hosts; and concerns about a possible pandemic involving avian influenza A and the importance of minimizing emergence of resistant strains of this highly pathogenic virus. The challenges in each area are different, but the general keys to addressing the growing problem of antimicrobial resistance continue to be responsible antimicrobial stewardship and the development of newer antimicrobial agents.

Performance of the BD GeneOhm methicillin-resistant Staphylococcus aureus test before and during high-volume clinical use

We evaluated the use of the BD GeneOhm MRSA real-time PCR assay (BD Diagnostics, San Diego, CA) for the detection of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA). The initial evaluation consisted of 403 paired nasal swabs and was done using the specimen preparation provided with the kit and an in-house lysis method that was specifically developed to accommodate large-volume testing using a minimal amount of personnel time. One swab was placed in an achromopeptidase (ACP) lysis solution, and the other was first used for culture and then prepared according to the kit protocol. PCR was performed on both lysates, and results were compared to those for culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PCR assay were 98%, 96%, 77%, and 99.7% with the kit lysate and 98%, 95%, 75%, and 99.7% with the ACP lysate (P, not significant), respectively. The second evaluation was done after implementation of all-admission surveillance using PCR with ACP lysis and a sampling of 1,107 PCR-negative samples and 215 PCR-positive samples that were confirmed by culture. The results of this sampling showed an NPV of 99.9% and a PPV of 73.5% (prevalence, 6%), consistent with our initial findings. The BD GeneOhm MRSA assay is an accurate and rapid way to detect MRSA nasal colonization. When one is dealing with large specimen numbers, the ACP lysis method offers easier processing without negatively affecting the sensitivity or specificity of the PCR assay.

Development and validation of measures to assess prevention and control of AMR in hospitals

BACKGROUND

The rapid spread of antimicrobial resistance (AMR) in the US hospitals poses serious quality and safety problems. Expert panels, identifying strategies for optimizing antibiotic use and preventing AMR spread, have recommended hospitals undertake efforts to implement specific evidence-based practices.

OBJECTIVE

To develop and validate a measurement scale for assessing hospitals' efforts to implement recommended AMR prevention and control measures.

STUDY DESIGN

Surveys were mailed to infection control professionals in a national sample of 670 US hospitals stratified by geographic region, bedsize, teaching status, and VA affiliation.

SUBJECTS

: Four hundred forty-eight infection control professionals participated (67% response rate).

METHODS

Survey items measured implementation of guideline recommendations, practices for AMR monitoring and feedback, AMR-related outcomes (methicillin-resistant Staphylococcus aureus prevalence and outbreaks [MRSA]), and organizational features. "Derivation" and "validation" samples were randomly selected. Exploratory factor analysis was performed to identify factors underlying AMR prevention and control efforts. Multiple methods were used for validation.

RESULTS

We identified 4 empirically distinct factors in AMR prevention and control: (1) practices for antimicrobial prescription/use, (2) information/resources for AMR control, (3) practices for isolating infected patients, and (4) organizational support for infection control policies. The Prevention and Control of Antimicrobial Resistance scale was reliable and had content and construct validity. MRSA prevalence was significantly lower in hospitals with higher resource/information availability and broader organizational support.

CONCLUSIONS

The Prevention and Control of Antimicrobial Resistance scale offers a simple yet discriminating assessment of AMR prevention and control efforts. Use should complement assessment methods based exclusively on AMR outcomes.

Antimicrobial resistance prevention initiative--an update: proceedings of an expert panel on resistance

Antimicrobial resistance is a growing problem that complicates the treatment of important nosocomial and community-acquired infections. It is a worldwide problem that spans the range of human pathogens, including bacteria, fungi, and viruses. This update from the Antimicrobial Resistance Prevention Initiative (ARPI) provides a review of some important trends in antibiotic, antifungal, and antiviral resistance. Areas of focus include multidrug-resistant bacteria in the hospital setting; the growing problem of community-acquired methicillin-resistant Staphylococcus aureus; triazole and polyene resistance in nosocomial infections caused by non-Candida albicans or Aspergillus species, and the utility of in vitro susceptibility testing for these fungal infections; antiviral resistance in alpha- or beta-herpesviruses causing genital herpes or cytomegalovirus infection in immunocompromised hosts; and concerns about a possible pandemic involving avian influenza A and the importance of minimizing emergence of resistant strains of this highly pathogenic virus. The challenges in each area are different, but the general keys to addressing the growing problem of antimicrobial resistance continue to be responsible antimicrobial stewardship and the development of newer antimicrobial agents.

Methicillin-resistant Staphylococcus aureus caruncle abscess

A 60-year-old woman under treatment for a left lower eyelid abscess developed a right caruncle abscess. Methicillin-resistant Staphylococcus aureus (MRSA) was identified in cultures performed on both lesions. Treatment consisted of oral ciprofloxacin and moxifloxacin drops. There was resolution of both lesions with incision and drainage, and antibiotic therapy. MRSA is a pathogen that can be readily isolated from the caruncle. The authors are unaware of previous reported cases of a MRSA caruncle abscess.

Effectiveness of bundled behavioural interventions to control healthcare-associated infections: a systematic review of the literature

Attempts to address the growing problem of healthcare-associated infections (HAIs) and their impact on healthcare systems have historically relied on infection control policies that recommend good hygiene through standard and enhanced precautions (e.g. barrier precautions and patient isolation). In order for infection control strategies to be effective, however, healthcare workers' behaviour must be congruent with these policies. The purposes of this systematic review were to evaluate studies testing the effectiveness of interventions aimed at changing healthcare workers' behaviour (in reducing HAIs) and to summarize the findings of the studies with the highest quality scores. A total of 33 published studies met the inclusion criteria and were evaluated. Four of these earned a study quality score of > or =80%. In all four significant reductions in HAI or colonization rates were reported. Behavioural interventions used in these high quality studies included an educational programme (in four), the formation of a multi-disciplinary quality improvement team (three), compliance monitoring and feedback (two), and a mandate to sign a hand hygiene requirement statement (one). In all 33 studies, bundles of two to five interventions were employed, making it difficult to determine the effectiveness of individual interventions. The usefulness of "care bundling" has recently been recognized and recommended by the Institute for Healthcare Improvement. Considering the multi-factorial nature of the HAI problem and the logistical and ethical difficulties of applying the randomized clinical trial approach to infection control research, it may be necessary to study interventions as sets of practices.

Cytotoxic 6-Alkylsalicylic Acids from the Endophytic Streptomyces laceyi

Two new 6-alkylsalicylic acids, salaceyins A and B were isolated by bioassay-guided fractionation from the culture of the endophytic Streptomyces laceyi MS53 and their structures were determined on the basis of spectroscopic data. Salaceyins A and B exhibited modest cytotoxicity against a human breast cancer cell line (SKBR3) with IC50 values of 3.0 and 5.5 microg/ml, respectively.