Instant Typing Is Essential to Detect Transmission of Extended-Spectrum Beta-Lactamase-Producing Klebsiella Species

Background

Infections with multidrug-resistant (MDR) microorganisms are an increasing threat to hospitalized patients. Although rapid typing of MDR microorganisms is required to apply targeted prevention measures, technical barriers often prevent this. We aimed to assess whether extended-spectrum beta-lactamase (ESBL)-producing Klebsiella species are transmitted between patients and whether routine, rapid typing is needed.

Methods

For 43 months, the clonality of all ESBL-producing Klebsiella isolates from patients admitted to Erasmus MC University Medical Center in Rotterdam, the Netherlands was assessed with Raman spectroscopy. A cluster was defined as n ≥2 patients who had identical isolates. Primary patients were the first patients in each cluster. Secondary patients were those identified with an isolate clonally related to the isolate of the primary patient.

Results

Isolates from 132 patients were analyzed. We identified 17 clusters, with 17 primary and 56 secondary patients. Fifty-nine patients had a unique isolate. Patients (n = 15) in four out of the 17 clusters were epidemiologically related. Ten of these 15 patients developed an infection.

Conclusions

Clonal outbreaks of ESBL-producing Klebsiella species were detected in our hospital. Theoretically, after Raman spectroscopy had detected a cluster of n ≥2, six infections in secondary patients could have been prevented. These findings demonstrate that spread of ESBL-producing Klebsiella species occurs, even in a non-outbreak setting, and underscore the need for routine rapid typing of these MDR bacteria.     

The way forward in biochar research: targeting trade‐offs between the potential wins

Biochar application to soil is currently widely advocated for a variety of reasons related to sustainability. Typically, soil amelioration with biochar is presented as a multiple‐‘win’ strategy, although it is also associated with potential risks such as environmental contamination. The most often claimed benefits of biochar (i.e. the ‘wins’) include (i) carbon sequestration; (ii) soil fertility enhancement; (iii) biofuel/bioenergy production; (iv) pollutant immobilization; and (v) waste disposal. However, the vast majority of studies ignore possible trade‐offs between them. For example, there is an obvious trade‐off between maximizing biofuel production and maximizing biochar production. Also, relatively little attention has been paid to mechanisms, as opposed to systems impacts, behind observed biochar effects, often leaving open the question as to whether they reflect truly unique properties of biochar as opposed to being simply the short‐term consequences of a fertilization or liming effect. Here, we provide an outline for the future of soil biochar research. We first identify possible trade‐offs between the potential benefits. Second, to be able to better understand and quantify these trade‐offs, we propose guidelines for robust experimental design and selection of appropriate controls that allow both mechanistic and systems assessment of biochar effects and trade‐offs between the wins. Third, we offer a conceptual framework to guide future experiments and suggest guidelines for the standardized reporting of biochar experiments to allow effective between‐site comparisons to quantify trade‐offs. Such a mechanistic and systems framework is required to allow effective comparisons between experiments, across scales and locations, to guide policy and recommendations concerning biochar application to soil.     

Selected polymorphisms in sex hormone-related genes, circulating sex hormones and risk of endometrial cancer

Background: The role of estrogen and progesterone in the development of endometrial cancer is well documented. Few studies have examined the association of genetic variants in sex hormone-related genes with endometrial cancer risk. Methods: We conducted a case-control study nested within three cohorts to examine the association of endometrial cancer risk with polymorphisms in hormone-related genes among 391 cases (92% postmenopausal at diagnosis) and 712 individually-matched controls. We also examined the association of these polymorphisms with circulating levels of sex hormones and SHBG in a cross-sectional analysis including 596 healthy postmenopausal women at blood donation (controls from this nested case-control study and from a nested case-control study of breast cancer in one of the three cohorts). Results: Adjusting for endometrial cancer risk factors, the A allele of rs4775936 in CYP19 was significantly associated (OR(per allele)=1.22, 95% CI=1.01-1.47, p(trend)=0.04), while the T allele of rs10046 was marginally associated with increased risk of endometrial cancer (OR(per allele)=1.20, 95% CI=0.99-1.45, p(trend)=0.06). PGR rs1042838 was also marginally associated with risk (OR(per allele)=1.25, 95% CI=0.96-1.61, p(trend)=0.09). No significant association was found for the other polymorphisms, i.e. CYP1B1 rs1800440 and rs1056836, UGT1A1 rs8175347, SHBG rs6259 and ESR1 rs2234693. Rs8175347 was significantly associated with postmenopausal levels of estradiol, free estradiol and estrone and rs6259 with SHBG and estradiol. Conclusion: Our findings support an association between genetic variants in CYP19, and possibly PGR, and risk of endometrial cancer.     

A multi-centre randomized controlled trial of rehabilitation aimed at improving outdoor mobility for people after stroke: study protocol for a randomized controlled trial

ABSTRACT: BACKGROUND: Up to 42% of all stroke patients do not get out of the house as much as they would like. This can impede a person's quality of life. This study is testing the clinical effectiveness and cost effectiveness of a new outdoor mobility rehabilitation intervention by comparing it to usual care. METHODS: Multi-centre parallel group individually randomised controlled trial. At least 506 participants will be recruited through 15 primary and secondary care settings and will be eligible if they are over 18 years of age, have had a stroke and wish to get out of the house more often. Participants are being randomly allocated to either the intervention group or the control group. Intervention group participants receive up to 12 rehabilitation outdoor mobility sessions over up to 4 months. The main component of the intervention is repeated practice of outdoor mobility with a therapist. Control group participants are receiving the usual intervention for outdoor mobility limitations: verbal advice and provision of leaflets provided over one session. Outcome measures are being collected using postal questionnaires, travel calendars and by independent assessors. The primary outcome measure is the Social Function domain of the SF36v2 quality of life assessment six months after recruitment. The secondary outcome measures include: functional ability, mobility, the number of journeys (monthly travel diaries), satisfaction with outdoor mobility, mood, health-related quality of life, resource use of health and social care. Carer mood is also being collected. The mean Social Function score of the SF-36v2 will be compared between treatment arms using a multiple membership form of mixed effects multiple regression analysis adjusting for centre (as a fixed effect), age and baseline Social Function score as covariates and therapist as a multiple membership random effect. Regression coefficients and 95% confidence intervals will be presented. DISCUSSION: This study protocol describes a pragmatic randomised controlled trial that will hopefully provide robust evidence of the benefit of outdoor mobility interventions after stroke for clinicians working in the community. The results will be available towards the end of 2012.     

Dispersal and diversity in experimental metacommunities: linking theory and practice

There has been a recent rise in the number of experiments investigating the effect of dispersal on diversity, with many of the predictions for these tests derived from metacommunity theory. Despite the promise of linking observed relationships between dispersal and diversity to underlying metacommunity processes, empirical studies have faced challenges in providing robust tests of theory. We review experimental studies that have tested how dispersal affects metacommunity diversity to determine why shortcomings emerge, and to provide a framework for empirical tests of theory that capture the processes structuring diversity in natural metacommunities. We first summarize recent experimental work to outline trends in results and to highlight common methods that cause a misalignment between empirical studies and the processes described by theory. We then identify the undesired implications of three widely used experimental methods that homogenize metacommunity structure or species traits, and present alternative methods that have been used to successfully integrate experiments and theory in a biologically relevant way. Finally, we present methodological and theoretical insights from three related ecological fields (coexistence, food web and priority effects theory) that, if integrated into metacommunity experiments, could help isolate the independent and joint effects of local interactions and dispersal on diversity, and reveal the mechanisms underlying observed dispersal–diversity patterns. Together, these methods can provide stronger tests of existing theory and stimulate new theoretical explorations. Synthesis Although metacommunity experiments offer a unique opportunity to test classic and emerging theory on the relationship between dispersal and diversity, several common challenges have hindered robust tests of theory. We outline how emerging theory on the invasion criterion, food webs and priority effects could be help clarify when and how dispersal affects metacommunity diversity, and identify when experimental approaches that homogenize metacommunities fail to test existing theory. By forging better links between theoretical and empirical work, we hope to motivate novel and improved experimental approaches to understanding the joint effects of local and regional processes on diversity.     

Comparative ultrastructural study of the effects of serum-free medium and dibutyryl-cyclic AMP on newborn rat astroblasts

Summary Modifications of cell shape induced in cultured newborn rat astroblasts by serum deprivation or dibutyryladenosine 3–5 monophosphate (dBcAMP) are described. Serum suppression modifies the adhesivity of the cells to the substrate, but this modification is not consistent with a true differentiation. The main ultrastructural feature of dBcAMP-treated astroblasts is the presence of an extensive system of 90 Å microfilaments, while control cells are relatively devoid of these structures.Dr. G. Moonen is Aspirant du Fonds National de la Recherche Scientifique.     

Kinetics of Anti-Mannan Antibodies Useful in Confirming Invasive Candidiasis in Immunocompromised Patients

In studying the anti-mannan antibodies longitudinally in serial serum samples of three immunocompromised patients, it was observed that anti-mannan antibodies started to increase shortly after the moment that cultures of deep-tissue sites became positive with Candida albicans. The mean anti-mannan antibody titers determined in a group of 36 immunocompromised patients with invasive candidiasis increased within two weeks after the probable onset of invasive candidiasis. In contrast, anti-mannan antibody levels in serial serum samples of 14 immunocompromised patients who were only colonized with C. albicans remained stable or decreased over time. The HA test measuring the anti-mannan antibodies was 64% sensitive and 89% specific in determining invasive candidiasis. In contrast, antibodies specific for candidal cytoplasmic antigens or enolase alone were of little value in confirming invasive candidiasis in these immunocompromised patients.