Anoxic Iron Cycling Bacteria from an Iron Sulfide- and Nitrate-Rich Freshwater Environment

In this study, both culture-dependent and culture-independent methods were used to determine whether the iron sulfide mineral- and nitrate-rich freshwater nature reserve Het Zwart Water accommodates anoxic microbial iron cycling. Molecular analyses (16S rRNA gene clone library and fluorescence in situ hybridization, FISH) showed that sulfur-oxidizing denitrifiers dominated the microbial population. In addition, bacteria resembling the iron-oxidizing, nitrate-reducing Acidovorax strain BrG1 accounted for a major part of the microbial community in the groundwater of this ecosystem. Despite the apparent abundance of strain BrG1-like bacteria, iron-oxidizing nitrate reducers could not be isolated, likely due to the strictly autotrophic cultivation conditions adopted in our study. In contrast an iron-reducing Geobacter sp. was isolated from this environment while FISH and 16S rRNA gene clone library analyses did not reveal any Geobacter sp.-related sequences in the groundwater. Our findings indicate that iron-oxidizing nitrate reducers may be of importance to the redox cycling of iron in the groundwater of our study site and illustrate the necessity of employing both culture-dependent and independent methods in studies on microbial processes

Cost-effectiveness of Magnetic Resonance (MR) Imaging and MR-guided Targeted Biopsy Versus Systematic Transrectal Ultrasound-guided Biopsy in Diagnosing Prostate Cancer: A Modelling Study from a Health Care Perspective

Item does not contain fulltextBACKGROUND: The current diagnostic strategy using transrectal ultrasound-guided biopsy (TRUSGB) raises concerns regarding overdiagnosis and overtreatment of prostate cancer (PCa). Interest in integrating multiparametric magnetic resonance imaging (MRI) and magnetic resonance-guided biopsy (MRGB) into the diagnostic pathway to reduce overdiagnosis and improve grading is gaining ground, but it remains uncertain whether this image-based strategy is cost-effective. OBJECTIVE: To determine the cost-effectiveness of multiparametric MRI and MRGB compared with TRUSGB. DESIGN, SETTING, AND PARTICIPANTS: A combined decision tree and Markov model for men with elevated prostate-specific antigen (>4 ng/ml) was developed. Input data were derived from systematic literature searches, meta-analyses, and expert opinion. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Quality-adjusted life years (QALYs) and health care costs of both strategies were modelled over 10 yr after initial suspicion of PCa. Probabilistic and threshold analyses were performed to assess uncertainty. RESULTS AND LIMITATIONS: Despite uncertainty around the presented cost-effectiveness estimates, our results suggest that the MRI strategy is cost-effective compared with the standard of care. Expected costs per patient were euro 2423 for the MRI strategy and euro 2392 for the TRUSGB strategy. Corresponding QALYs were higher for the MRI strategy (7.00 versus 6.90), resulting in an incremental cost-effectiveness ratio of euro 323 per QALY. Threshold analysis revealed that MRI is cost-effective when sensitivity of MRGB is >/= 20%. The probability that the MRI strategy is cost-effective is around 80% at willingness to pay thresholds higher than euro 2000 per QALY. CONCLUSIONS: Total costs of the MRI strategy are almost equal with the standard of care, while reduction of overdiagnosis and overtreatment with the MRI strategy leads to an improvement in quality of life. PATIENT SUMMARY: We compared costs and quality of life (QoL) of the standard "blind" diagnostic technique with an image-based technique for men with suspicion of prostate cancer. Our results suggest that costs were comparable, with higher QoL for the image-based technique

Reply to Sarah Willis, Alec Miners, and Jan van der Meulen's letter to the editor re: Maarten de Rooij, Simone Crienen, J. Alfred Witjes, Jelle O. Barentsz, Maroeska M. Rovers, Janneke P.C. Grutters. Cost-effectiveness of magnetic resonance (MR) imaging and MR-guided targeted biopsy versus systematic transrectal ultrasound-guided biopsy in diagnosing prostate cancer: a modelling study from a health care perspective. Eur Urol. In press. http://dx.doi.org/10.1016/j.eururo.2013.12.012

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Prevalence and risk factors of Brachyspira spp. in pig herds with a history of diarrhoea in six European countries.

Swine dysentery and porcine intestinal spirochaetosis caused by Brachyspira (B.) hyodysenteriae and B. pilosicoli, respectively, are important diseases in swine production worldwide. The aim of this study was to assess the prevalence of both pathogens in farms with a history of diarrhoea within the last 12 months in Denmark, France, Germany, the Netherlands, Spain, and United Kingdom. In addition, risk factors for their prevalence and correlations between presence of different Brachyspira spp. and Lawsonia intracellularis were investigated. Therefore, faecal samples of 6355 nursery to finishing pigs out of 144 herds were sampled in 2017/2018 during a prevalence study on Lawsonia intracellularis, followed by polymerase chain reaction analysis for Brachyspira spp. detection. Herd prevalence differed significantly between countries, from 4.2% to 45.8% for B. hyodysenteriae and 8.3-87.5% for B. pilosicoli, respectively (p < 0.01). For the within-herd prevalence (in positive herds), these values ranged from 2.2% to 27.0% for B. hyodysenteriae and 3.3-50.8% for B. pilosicoli. Mixed infections occurred in 34.1% and 58.7% of B. hyodysenteriae positive samples with Lawsonia intracellularis or B. pilosicoli, respectively. In 43.2% of B. pilosicoli positive samples, Lawsonia intracellularis was detected simultaneously. Overall, nursery pigs were significantly less often positive for one of the pathogens than growing or finishing pigs (p < 0.001). The absence of gastrointestinal problems like diarrhoea, routine use of antimicrobials and well performed biosecurity measures were some of the factors associated with lower detection rate of Brachyspira spp. Surprisingly, deworming of different age categories also showed associations with the detection of Brachyspira spp. which, however, were not always equally directed, and therefore require further investigations. The only risk factor significant for both Brachyspira spp. was the median number of ≥ 30 nursery pigs per pen after weaning, compared to smaller group sizes. Both pathogens were detected with varying frequency between the six European countries. This should be considered in the probability of disease and in case of transnational transport, to prevent spread of pathogens. In addition, the frequent presence of mixed infections in some countries should be taken into account in diagnostics. The most important protective factors against Brachyspira spp. presence on farm are biosecurity measures, while potential new factors such as deworming still require further investigation