Fungicide resistance among Cladobotryum spp. – causal agents of cobweb disease of the edible mushroom Agaricus bisporus

A survey of fungicide resistance among isolates of the mushroom pathogens Cladobotryum mycophilum and C. dendroides Types I and II was undertaken, with respect to the active ingredients thiabendazole, carbendazim (benzimidazoles) and prochloraz manganese following an epidemic in Britain and Ireland in 1994/95. The majority of isolates (41/57) were strongly resistant to thiabendazole (ED50 > 200 ppm) and were exclusively C. dendroides Type II. All C. mycophilum and C. dendroides Type I isolates, and four C. dendroides Type II isolates, were weakly resistant to thiabendazole (ED50 1–10 ppm). Thiabendazole-resistant C. dendroides Type II isolates were only weakly resistant to carbendazim (ED50 2–10 ppm) and isolates which were weakly resistant to thiabendazole were carbendazim-sensitive (ED50 < 1 ppm), demonstrating a lack of complete cross resistance between these two benzimidazole fungicides. The ED50 values for all isolates with respect to prochloraz manganese ranged from 0.14 to 7.8 ppm. Benzimidazole resistance was considered to have been an important factor influencing the severity of the 1994/95 cobweb epidemic but 25% of isolates collected were benzimidazole sensitive

Networking strategies in streptomyces coelicolor

We are interested the soil dwelling bacteria Streptomyces coelicolor because its cells grow end to end in a line. New branches have the potential to extend from any point along this line and the result is a network of branches and connections. This is a novel form of colonisation in the bacterial world and it is advantageous for spreading through an environment resourcefully. Networking protocols for communication technologies have similar pressures to be resourceful in terms of time, computing power, and energy. In this preliminary investigation we design a computer model of the biological system to understand its limitations and strategies for survival. The decentralised capacity for organisation of both the bacterial system and the model reflects well on the now-popular conventions for path finding and ad hoc network building in human technologies. The project will ultimately become a comparison of strategies between nature and the man-made

Prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the United Kingdom

Prevalence of three sulfonamide resistance genes, sul1, sul2 and sul3 and sulfachloropyridazine (SCP) resistance was determined in bacteria isolated from UK manured agricultural clay soils and slurry samples, over a two year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline (OTC) was used for manuring. Sul gene positive isolates were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in pig slurry and post application soil than in pre-application soil. Of 5isolates, 23 % carried sul1, 18 % sul2 and 9 % sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5 % and 11.7 % of sul positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8 % of sul1 positive isolates carried the intI1 gene. Sulfonamide resistant pathogens were identified in slurry amended soil and soil leachate, including Shigella flexneri, Aerococcus spp. and Acinetobacter baumanni, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotype sul1, sul2 and sul3 outside the Enterobacteriacae, and in the soil environment

Environmental monitoring of Mycobacterium bovis in badger feces and badger sett soil by real-time PCR, as confirmed by immunofluorescence, immunocapture, and cultivation

Real-time PCR was used to detect and quantify Mycobacterium bovis cells in naturally infected soil and badger faeces. Immunomagnetic capture, immunofluorescence and selective culture confirmed species identification and cell viability. These techniques will prove useful for monitoring M. bovis in the environment and for elucidating transmission routes between wildlife and cattle

Double-stranded RNA elements associated with the MVX disease of Agaricus bisporus

Double-stranded RNA (dsRNA) has been isolated from Agaricus bisporus fruit bodies exhibiting a wide range of disease symptoms. The symptoms which occurred singularly or in combination included; bare cropping areas on commercial beds (primordia disruption), crop delay, premature veil opening, off- or brown-coloured mushrooms, sporophore malformations and loss of crop yield. All symptoms were associated with loss of yield and/or product quality. Collectively, these symptoms are described as mushroom virus X (MVX) disease. The dsRNA titre was much lower than that previously encountered with the La France viral disease of mushrooms and a modified cellulose CF11 protocol was used for their detection. A broad survey of cultivated mushrooms from the British industry identified dsRNA elements ranging between 640 bp and 20.2 kbp; the majority have not previously been described in A. bisporus. 26 dsRNA elements were identified with a maximum of 17, apparently non-encapsidated dsRNA elements, in any one sample. Three dsRNAs (16.2, 9.4 and 2.4 kbp) were routinely found in mushrooms asymptomatic for MVX. Previously, La France disease was effectively contained and controlled by minimising the on-farm production and spread of basidiospores. Our on-farm observations suggest that MVX could be spread by infected spores and/or mycelial fragments

Integron prevalence and diversity in manured soil

Integron abundance and diversity were studied in soil amended with pig slurry. Real-time PCR illustrated a significant increase in class 1 integron prevalence post slurry-application with increased prevalence still evident at 10 months post-application. Culture dependent data revealed 10 genera, including putative human pathogens, carrying class 1 and 2 integrons

Neuroendocrine morbidity after pediatric optic gliomas: a longitudinal analysis of 166 children over 30 years

Context: 50% of pediatric low-grade gliomas affect the optic pathway, hypothalamus and suprasellar areas (OP/HSGs) resulting in significant long-term neuroendocrinopathy. Objective: To dissect tumor- from treatment-related risk factors for OP/HSG-associated neuroendocrinopathy. Design: Retrospective case notes analysis of 166 children with newly-diagnosed OP/HSGs at our quaternary center between 1980 –2010 by multivariate Cox, linear and logistic regression. Results: Patients were of median (range) age 4.9 (0.2–15.4) years at diagnosis and followed up for 8.3 (0.04 –26.8) years. Despite high 20-year overall survival (81.0%), progression-free and endocrine event-free (EEFS) survival were 47.2% and 20.8% respectively. EEFS declined up to 15 years postdiagnosis, with hypothalamic involvement (p0.001) being implicated more than radiotherapy (p0.008) in earlier endocrinopathy; the reverse being true of its density (radiotherapy p0.001; hypothalamic involvement p0.006). GH deficiency (GHD) was commonest (40.3%), followed by central precocious puberty (CPP, 26.0%), gonadotropin (GnD, 20.4%), TSH (13.3%), and ACTH (13.3%) deficiencies. GHD increased with later treatment eras (p0.01), but replacement did not increase progression. CPP was associated with future GnD (p0.05). Posterior pituitary dysfunction (PPD, 7.2%) occurred in 57.9% after only biopsies or shunt procedures, and was associated with 6/13 deaths. 50.2% became obese. Tumor extent, surgery and increased endocrinopathy, rather than radiotherapy, predicted visuo-cognitive morbidity. Conclusions: This first longitudinal OP/HSG-specific study demonstrates that hypothalamo-pituitary dysfunction evolves hierarchically over decades. Tumor location predicts its speed of onset and radiotherapy its density. GnD can evolve from previous CPP, whilst life-threatening PPD can occur after any surgery. Our data suggest that recent radiation-avoiding chemotherapeutic strategies have increased GHD without improving survival

Is it safe to go back into the water? A systematic review and meta-analysis of the risk of acquiring infections from recreational exposure to seawater

Background: Numerous illnesses are associated with bathing in natural waters, although it is assumed that the risk of illness among bathers exposed to relatively clean waters found in high-income countries is negligible. A systematic review was carried out to quantify the increased risk of experiencing a range of adverse health outcomes among bathers exposed to coastal water compared with non-bathers. Methods: In all 6919 potentially relevant titles and abstracts were screened, and from these 40 studies were eligible for inclusion in the review. Odds ratios (OR) were extracted from 19 of these reports and combined in random-effect meta-analyses for the following adverse health outcomes: incident cases of any illness, ear infections, gastrointestinal illness and infections caused by specific microorganisms. Results: There is an increased risk of experiencing symptoms of any illness [OR = 1.86, 95% confidence interval (CI): 1.31 to 2.64, P = 0.001] and ear ailments (OR = 2.05, 95% CI: 1.49 to 2.82, P < 0.001) in bathers compared with non-bathers. There is also an increased risk of experiencing gastrointestinal ailments (OR = 1.29, 95% CI: 1.12 to 1.49, P < 0.001). Conclusions: This is the first systematic review to evaluate evidence on the increased risk of acquiring illnesses from bathing in seawater compared with non-bathers. Our results support the notion that infections are acquired from bathing in coastal waters, and that bathers have a greater risk of experiencing a variety of illnesses compared with non-bathers

Trace levels of sewage effluent are sufficient to increase class 1 integron prevalence in freshwater biofilms without changing the core community

Most river systems are impacted by sewage effluent. It remains unclear if there is a lower threshold to the concentration of sewage effluent that can significantly change the structure of the microbial community and its mobile genetic elements in a natural river biofilm. We used novel in situ mesocosms to conduct replicated experiments to study how the addition of low-level concentrations of sewage effluent (nominally 2.5 ppm) affects river biofilms in two contrasting Chalk river systems, the Rivers Kennet and Lambourn (high/low sewage impact, respectively). 16S sequencing and qPCR showed that community composition was not significantly changed by the sewage effluent addition, but class 1 integron prevalence (Lambourn control 0.07% (SE ± 0.01), Lambourn sewage effluent 0.11% (SE ± 0.006), Kennet control 0.56% (SE ± 0.01), Kennet sewage effluent 1.28% (SE ± 0.16)) was significantly greater in the communities exposed to sewage effluent than in the control flumes (ANOVA, F = 5.11, p = 0.045) in both rivers. Furthermore, the difference in integron prevalence between the Kennet control (no sewage effluent addition) and Kennet sewage-treated samples was proportionally greater than the difference in prevalence between the Lambourn control and sewage-treated samples (ANOVA (interaction between treatment and river), F = 6.42, p = 0.028). Mechanisms that lead to such differences could include macronutrient/biofilm or phage/bacteria interactions. Our findings highlight the role that low-level exposure to complex polluting mixtures such as sewage effluent can play in the spread of antibiotic resistance genes. The results also highlight that certain conditions, such as macronutrient load, might accelerate spread of antibiotic resistance genes