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Journal articles on the topic 'Environmental pathogens'
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1
Quinlan, Robert J. "Human parental effort and environmental risk." Proceedings of the Royal Society B: Biological Sciences 274, no. 1606 (October 18, 2006): 121–25. http://dx.doi.org/10.1098/rspb.2006.3690.
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Parental investment decisions depend on multiple factors, including the extent that parental care benefits offspring. Humans should show reduced parental effort in environments where parenting cannot improve offspring survival. Data from the standard cross-cultural sample are used to test this prediction. The results show that maternal care was inversely associated with famine and warfare, and also showed a quadratic association with pathogen stress, increasing as pathogen stress increased to moderate levels, but decreasing at higher levels. Age at weaning showed a similar quadratic relation with pathogens. The curvilinear associations between parental effort and pathogen stress may reflect that the saturation point of parental care is a function of environmental hazards. Paternal involvement was also inversely related to pathogen stress. The association between pathogens and paternal involvement was partially mediated by polygyny. In sum, maternal and paternal care appears to have somewhat different relations with environmental hazards, presumably owing to sex-specific tradeoffs in reproductive effort.
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Lanzas, Cristina, Kale Davies, Samantha Erwin, and Daniel Dawson. "On modelling environmentally transmitted pathogens." Interface Focus 10, no. 1 (December 13, 2019): 20190056. http://dx.doi.org/10.1098/rsfs.2019.0056.
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Many pathogens are able to replicate or survive in abiotic environments. Disease transmission models that include environmental reservoirs and environment-to-host transmission have used a variety of functional forms and modelling frameworks without a clear connection to pathogen ecology or space and time scales. We present a conceptual framework to organize microparasites based on the role that abiotic environments play in their lifecycle. Mean-field and individual-based models for environmental transmission are analysed and compared. We show considerable divergence between both modelling approaches when conditions do not facilitate well mixing and for pathogens with fast dynamics in the environment. We conclude with recommendations for modelling environmentally transmitted pathogens based on the pathogen lifecycle and time and spatial scales of the host–pathogen system under consideration.
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Anttila, Jani, Jouni Laakso, Veijo Kaitala, and Lasse Ruokolainen. "Environmental variation enables invasions of environmental opportunist pathogens." Oikos 125, no. 8 (November 27, 2015): 1144–52. http://dx.doi.org/10.1111/oik.02913.
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Leach, Clinton B., Colleen T. Webb, and Paul C. Cross. "When environmentally persistent pathogens transform good habitat into ecological traps." Royal Society Open Science 3, no. 3 (March 2016): 160051. http://dx.doi.org/10.1098/rsos.160051.
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Habitat quality plays an important role in the dynamics and stability of wildlife metapopulations. However, the benefits of high-quality habitat may be modulated by the presence of an environmentally persistent pathogen. In some cases, the presence of environmental pathogen reservoirs on high-quality habitat may lead to the creation of ecological traps, wherein host individuals preferentially colonize high-quality habitat, but are then exposed to increased infection risk and disease-induced mortality. We explored this possibility through the development of a stochastic patch occupancy model, where we varied the pathogen’s virulence, transmission rate and environmental persistence as well as the distribution of habitat quality in the host metapopulation. This model suggests that for pathogens with intermediate levels of spread, high-quality habitat can serve as an ecological trap, and can be detrimental to host persistence relative to low-quality habitat. This inversion of the relative roles of high- and low-quality habitat highlights the importance of considering the interaction between spatial structure and pathogen transmission when managing wildlife populations exposed to an environmentally persistent pathogen.
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Pedersen, Joel A., Katherine D. McMahon, and Craig H. Benson. "Prions: Novel Pathogens of Environmental Concern?" Journal of Environmental Engineering 132, no. 9 (September 2006): 967–69. http://dx.doi.org/10.1061/(asce)0733-9372(2006)132:9(967).
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Rysanek, Dusan, Monika Zouharova, and Vladimir Babak. "Monitoring major mastitis pathogens at the population level based on examination of bulk tank milk samples." Journal of Dairy Research 76, no. 1 (January 5, 2009): 117–23. http://dx.doi.org/10.1017/s0022029908003816.
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The objective was to determine the proportions and bacterial counts of major mastitis pathogens in samples of bulk tank milk (BTM), as well as to clarify the relationship between these bacteria counts and bulk tank somatic cell count (BTSCC). The purpose was to judge the importance of the counts of mammary pathogens for BTSCC at the population level. Samples of BTM were collected from 268 randomly selected anonymous dairy herds (with approximately 29 000 dairy cows). Staphylococcus aureus, other coagulase-positive staphylococci, Streptococcus agalactiae and Streptococcus dysgalactiae were grouped as contagious pathogens, and Streptococcus uberis, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Enterococcus faecium as environmental pathogens. Based on assessment of the dominant pathogen in each herd, environmental pathogens were found to dominate. Counts of specific mammary pathogens in BTM samples did not exceed a geometric mean of 1000 cfu/ml. Significant differences were documented in BTSCC between BTM samples containing Str. agalactiae, Staph. aureus, and Str. dysgalactiae and BTM samples that were pathogen-free. Geometric means of BTSCC associated with these pathogens were noticeably higher than the overall BTSCC (Str. agalactiae 243 628; Staph. aureus 205 610; Str. dysgalactiae 203 978; overall 173 000 cells/ml). It follows that the somatic cell count (SCC) associated with these pathogens contributed substantially to the overall BTSCC. Environmental pathogens predominated in samples of BTM with SCC <300×103/ml and contagious mastitis pathogens predominated in BTM samples with SCC >300×103/ml. No correlation was detected between bacterial counts of specific pathogens and BTSCC. This study revealed that the assessment of bacterial counts of mammary pathogens in samples of BTM in relation to BTSCC is applicable for the monitoring of changes in the occurrence of major mastitis pathogens in dairy herds at a national level.
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Shea, Dylan, Andrew Bateman, Shaorong Li, Amy Tabata, Angela Schulze, Gideon Mordecai, Lindsey Ogston, et al. "Environmental DNA from multiple pathogens is elevated near active Atlantic salmon farms." Proceedings of the Royal Society B: Biological Sciences 287, no. 1937 (October 21, 2020): 20202010. http://dx.doi.org/10.1098/rspb.2020.2010.
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The spread of infection from reservoir host populations is a key mechanism for disease emergence and extinction risk and is a management concern for salmon aquaculture and fisheries. Using a quantitative environmental DNA methodology, we assessed pathogen environmental DNA in relation to salmon farms in coastal British Columbia, Canada, by testing for 39 species of salmon pathogens (viral, bacterial, and eukaryotic) in 134 marine environmental samples at 58 salmon farm sites (both active and inactive) over 3 years. Environmental DNA from 22 pathogen species was detected 496 times and species varied in their occurrence among years and sites, likely reflecting variation in environmental factors, other native host species, and strength of association with domesticated Atlantic salmon. Overall, we found that the probability of detecting pathogen environmental DNA (eDNA) was 2.72 (95% CI: 1.48, 5.02) times higher at active versus inactive salmon farm sites and 1.76 (95% CI: 1.28, 2.42) times higher per standard deviation increase in domesticated Atlantic salmon eDNA concentration at a site. If the distribution of pathogen eDNA accurately reflects the distribution of viable pathogens, our findings suggest that salmon farms serve as a potential reservoir for a number of infectious agents; thereby elevating the risk of exposure for wild salmon and other fish species that share the marine environment.
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Ao, Dong, Yue Huang, Tao Xue, Nan Wang, and Rong Chen. "Implication of environmental factors on the occurrence of pathogens in urban landscape ponds with reclaimed wastewater replenishment." Blue-Green Systems 1, no. 1 (January 1, 2019): 119–33. http://dx.doi.org/10.2166/bgs.2019.916.
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Abstract One year of continuous observation of bacterial and viral pathogen concentrations in overlying water and sediment of three urban landscape ponds replenished with reclaimed wastewater (RW) ponds was carried out to establish the distribution of pathogens and investigate the effects of environmental factors on that in RW ponds. The pathogens were represented by Escherichia coli and three common viral pathogens (enterovirus, norovirus, and rotavirus). Results indicated that the peak concentrations of pathogens occur from August to October. Pathogens present in sediment should be paid much more attention than those in overlying water, as they mainly contribute to the favorable conditions for survival and regrowth of pathogens in sediments. Cluster and redundancy analyses revealed that the environmental factors of chlorophyll a (Chl-a), organic matter, and water transparency have key impacts on the occurrence of pathogens. This infers that the practical way to reduce pathogenic risks in RW ponds is to control the algae bloom and improve the transparency of water bodies. Furthermore, based on breakpoint regression analyses, the appropriate ranges of Chl-a and transparency are suggested to be less than 57 mg/m3 and greater than 68 cm, respectively, to reduce the concentration of pathogens in urban landscape ponds replenished with RW.
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Hua, Megan, William Huang, Albert Chen, Michael Rehmet, Cade Jin, and Zuyi Huang. "Comparison of Antimicrobial Resistance Detected in Environmental and Clinical Isolates from Historical Data for the US." BioMed Research International 2020 (April 13, 2020): 1–11. http://dx.doi.org/10.1155/2020/4254530.
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Antimicrobial resistance (AMR) has become an urgent public health issue, as pathogens are becoming increasingly resistant to commonly used antimicrobials. While AMR isolate data are available in the NCBI Pathogen Detection Isolates Browser (NPDIB) database, few researches have been performed to compare antimicrobial resistance detected in environmental and clinical isolates. To address this, this work conducted the first multivariate statistical analysis of antimicrobial-resistance pathogens detected in NPDIB clinical and environmental isolates for the US from 2013 to 2018. The highly occurring AMR genes and pathogens were identified for both clinical and environmental settings, and the historical profiles of those genes and pathogens were then compared for the two settings. It was found that Salmonella enterica and E. coli and Shigella were the highly occurring AMR pathogens for both settings. Additionally, the genes fosA, oqxB, ble, floR, fosA7, mcr-9.1, aadA1, aadA2, ant(2”)-Ia, aph(3”)-Ib, aph(3’)-Ia, aph(6)-Id, blaTEM-1, qacEdelta1, sul1, sul2, tet(A), and tet(B) were mostly detected for both clinical and environmental settings. Ampicillin, ceftriaxone, gentamicin, tetracycline, and cefoxitin were the antimicrobials which got the most resistance in both settings. The historical profiles of these genes, pathogens, and antimicrobials indicated that higher occurrence frequencies generally took place earlier in the environmental setting than in the clinical setting.
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Miller, S. E., and D. N. Howell. "Extreme Pathogens." Microscopy and Microanalysis 6, S2 (August 2000): 638–39. http://dx.doi.org/10.1017/s1431927600035686.
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Organisms are generally designated as “extreme” when they possess adaptations that allow them to flourish when one or more environmental parameters (e.g., temperature, ionizing radiation, oxygen, water, nutrients, inorganic ions) are at unusually high or low levels. A trade-off for this extraordinary resilience is that such organisms often grow poorly (if at all) in more conventional milieus. As a result, few of them are mammalian pathogens. (Anaerobic bacteria, which frequently thrive in the hypoxic conditions afforded by devitalized tissue, are an exception to this rule.)A broader definition of “extremity” encompasses all organisms that occupy narrow or unusual environmental niches. In this more inclusive scheme, a wealth of viruses, bacteria, fungi, and parasites with pathogenic potential in humans can be considered extreme. These organisms often pose formidable diagnostic challenges. Many have extremely narrow host ranges, rendering passage in animals and development of model systems for infection difficult or impossible.
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Jánosi, Sz, Margit Kulcsár, P. Kóródi, L. Kátai, J. Reiczigel, S. J. Dieleman, Judit Anna Nikolic, G. Sályi, Piroska Ribiczey-Szabó, and Gy Huszenicza. "Energy imbalance related predisposition to mastitis in group-fed high-producing postpartum dairy cows." Acta Veterinaria Hungarica 51, no. 3 (July 1, 2003): 409–24. http://dx.doi.org/10.1556/avet.51.2003.3.14.
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The energy imbalance related predisposition to mastitis was studied in group-fed postpartum dairy cows (n = 333) kept in 4 large-scale units and producing milk of low somatic cell count (SCC). Blood samples were taken on Days 1-3 after calving for assaying some metabolites and hormones related to the negative energy balance (NEB). If mastitis was diagnosed later, aseptic milk samples were taken to identify the pathogens. Considering pathogen types [contagious pathogens: Staphylococcus (S.) aureus, Gram-positive (GP) environmental pathogens, and Gram-negative (GN) environmental pathogens + mastitis with no detectable pathogens (NDP)] separately, stepwise logistic regression was used to analyse the relation between the potential prognostic value of hormones and metabolites and mastitis outbreak. Only the elevated (= 1.00 mmol/l) serum ß-hydroxybutyrate (BHB) levels predisposed the cows to mastitis in the subsequent 4 weeks. This prognostic value of BHB was significant only in GN + NDP mastitis and in cases caused by GP environmental pathogens, but not in S. aureus mastitis (odds ratio: 5.333, 3.600 and 1.333, respectively).
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Kett, GF, SC Culloty, SA Lynch, and MAK Jansen. "Solar UV radiation modulates animal health and pathogen prevalence in coastal habitats—knowledge gaps and implications for bivalve aquaculture." Marine Ecology Progress Series 653 (October 29, 2020): 217–31. http://dx.doi.org/10.3354/meps13464.
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Ultraviolet radiation (UVR) is an important environmental factor that can have an impact directly, or indirectly, on the health of organisms. UVR also has the potential to inactivate pathogens in surface waters. As a result, UVR can alter host-pathogen relationships. Bivalve species are threatened by various pathogens. Here, we assessed the impacts of UVR on (i) bivalves, (ii) bivalve pathogens and (iii) the bivalve host-pathogen relationship. UVR consistently impedes pathogens. However, the effect of UVR on marine animals is variable, with both positive and negative impacts. The limited available data allude to the potential to exploit natural UVR for disease management in aquaculture, but also highlight a striking knowledge gap and uncertainty relating to climate change.
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Delavaux, Camille S., Josh L. Schemanski, Geoffrey L. House, Alice G. Tipton, Benjamin Sikes, and James D. Bever. "Root pathogen diversity and composition varies with climate in undisturbed grasslands, but less so in anthropogenically disturbed grasslands." ISME Journal 15, no. 1 (September 21, 2020): 304–17. http://dx.doi.org/10.1038/s41396-020-00783-z.
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AbstractSoil-borne pathogens structure plant communities, shaping their diversity, and through these effects may mediate plant responses to climate change and disturbance. Little is known, however, about the environmental determinants of plant pathogen communities. Therefore, we explored the impact of climate gradients and anthropogenic disturbance on root-associated pathogens in grasslands. We examined the community structure of two pathogenic groups—fungal pathogens and oomycetes—in undisturbed and anthropogenically disturbed grasslands across a natural precipitation and temperature gradient in the Midwestern USA. In undisturbed grasslands, precipitation and temperature gradients were important predictors of pathogen community richness and composition. Oomycete richness increased with precipitation, while fungal pathogen richness depended on an interaction of precipitation and temperature, with precipitation increasing richness most with higher temperatures. Disturbance altered plant pathogen composition and precipitation and temperature had a reduced effect on pathogen richness and composition in disturbed grasslands. Because pathogens can mediate plant community diversity and structure, the sensitivity of pathogens to disturbance and climate suggests that degradation of the pathogen community may mediate loss, or limit restoration of, native plant diversity in disturbed grasslands, and may modify plant community response to climate change.
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Ryšánek, Dušan, Monika Zouharová, and Vladimír Babák. "Major Mammary Pathogens as Contributors to Total Bacterial Counts in Raw Milk." Acta Veterinaria Brno 78, no. 3 (2009): 455–61. http://dx.doi.org/10.2754/avb200978030455.
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The purpose of this study was to assess the contribution of major mammary pathogens, as well as of coliform and Gram-negative non-coliform bacteria to standard plate counts (SPCs) of bulk tank milk samples (BTMSs). Randomly selected anonymous BTMSs were collected from 268 dairy herds (with approximately 29,000 cows) in the Czech Republic during 2007. The most frequently detected pathogens were found to be E. faecalis (16.1%; geometric mean 9.8 × 102 CFU/ml) and S. uberis (13.6%; 9.0 × 102 CFU/ml). Highly significant positive correlations (P < 0.01) between the bacterial counts of the dominant pathogens and the relevant SPC were found for E. faecalis and S. dysgalactiae, as were significant correlations (P < 0.05) for S. uberis, E. faecium, and S. aureus. Highly significant positive correlations (P < 0.01) were found between SPC and coliform count and between SPC and Gram-negative non-coliform bacteria count. The results suggest, therefore, a recent dominance of environmental pathogens especially streptococci and enterococci, over contagious mammary pathogens in BTMSs. The geometric means of SPC in BTMSs with mammary pathogen (7.7 × 104 CFU/ml for environmental; 7.4 × 104 CFU/ml for contagious pathogens) exceed significantly (P < 0.05) the geometric means of SPC of pathogen free BTMSs (4.4 × 104 CFU/ml). This study revealed that the major mammary pathogens contribute significantly to SPCs of BTMSs.
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Brusina, Е. В., E. A. Chezganova, and О. M. Drozdova. "Airborne transmission of hospital pathogens." Fundamental and Clinical Medicine 5, no. 4 (December 25, 2020): 97–103. http://dx.doi.org/10.23946/2500-0764-2020-5-4-97-103.
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For decades, there have been a number of controversial issues regarding the airborne transmission of hospital pathogens. Here we decided to perform a critical review on this topic in light of the current COVID-19 pandemic. We summarise the existing knowledge on biological aerosols including techniques of their generation, propagation of bioaerosol particles in a hospital environment, particle size-, shape- and composition-dependent airborne transmission, and microorganisms inhabitating such particles. It is still unclear which of the particles transfer the pathogens, which of the pathogens are capable of adhering to the particulate matter, and whether such adhesion affects pathogen virulence. Intriguingly, viruses, bacteria and fungi seemingly have distinct patterns of interactions with the bioaerosols. Moreover, particle formation and their colonization may be separated in time, further complicating the puzzle. Apparently, pathogen interactions with the particulate matter are of paramount importance to better understand the role of bioaerosol particles as a potential pathogen reservoir in the hospital environment and to properly assess the influence of environmental pollutants, novel biomedical materials and treatment technologies on airborne transmission of hospital pathogens.
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Poole, Grant J., Martin Harries, D. Hüberli, S. Miyan, W. J. MacLeod, Roger Lawes, and A. McKay. "Predicting Cereal Root Disease in Western Australia Using Soil DNA and Environmental Parameters." Phytopathology® 105, no. 8 (August 2015): 1069–79. http://dx.doi.org/10.1094/phyto-07-14-0203-r.
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Root diseases have long been prevalent in Australian grain-growing regions, and most management decisions to reduce the risk of yield loss need to be implemented before the crop is sown. The levels of pathogens that cause the major root diseases can be measured using DNA-based services such as PreDicta B. Although these pathogens are often studied individually, in the field they often occur as mixed populations and their combined effect on crop production is likely to vary across diverse cropping environments. A 3-year survey was conducted covering most cropping regions in Western Australia, utilizing PreDicta B to determine soilborne pathogen levels and visual assessments to score root health and incidence of individual crop root diseases caused by the major root pathogens, including Rhizoctonia solani (anastomosis group [AG]-8), Gaeumannomyces graminis var. tritici (take-all), Fusarium pseudograminearum, and Pratylenchus spp. (root-lesion nematodes) on wheat roots for 115, 50, and 94 fields during 2010, 2011, and 2012, respectively. A predictive model was developed for root health utilizing autumn and summer rainfall and soil temperature parameters. The model showed that pathogen DNA explained 16, 5, and 2% of the variation in root health whereas environmental parameters explained 22, 11, and 1% of the variation in 2010, 2011, and 2012, respectively. Results showed that R. solani AG-8 soil pathogen DNA, environmental soil temperature, and rainfall parameters explained most of the variation in the root health. This research shows that interactions between environment and pathogen levels before seeding can be utilized in predictive models to improve assessment of risk from root diseases to assist growers to plan more profitable cropping programs.
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Ngashangva, Lightson, Bahaa A. Hemdan, Mohamed Azab El-Liethy, Vinay Bachu, Shelley D. Minteer, and Pranab Goswami. "Emerging Bioanalytical Devices and Platforms for Rapid Detection of Pathogens in Environmental Samples." Micromachines 13, no. 7 (July 8, 2022): 1083. http://dx.doi.org/10.3390/mi13071083.
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The development of robust bioanalytical devices and biosensors for infectious pathogens is progressing well with the advent of new materials, concepts, and technology. The progress is also stepping towards developing high throughput screening technologies that can quickly identify, differentiate, and determine the concentration of harmful pathogens, facilitating the decision-making process for their elimination and therapeutic interventions in large-scale operations. Recently, much effort has been focused on upgrading these analytical devices to an intelligent technological platform by integrating them with modern communication systems, such as the internet of things (IoT) and machine learning (ML), to expand their application horizon. This review outlines the recent development and applications of bioanalytical devices and biosensors to detect pathogenic microbes in environmental samples. First, the nature of the recent outbreaks of pathogenic microbes such as foodborne, waterborne, and airborne pathogens and microbial toxins are discussed to understand the severity of the problems. Next, the discussion focuses on the detection systems chronologically, starting with the conventional methods, advanced techniques, and emerging technologies, such as biosensors and other portable devices and detection platforms for pathogens. Finally, the progress on multiplex assays, wearable devices, and integration of smartphone technologies to facilitate pathogen detection systems for wider applications are highlighted.
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Aleta, Alberto, Andreia N. S. Hisi, Sandro Meloni, Chiara Poletto, Vittoria Colizza, and Yamir Moreno. "Human mobility networks and persistence of rapidly mutating pathogens." Royal Society Open Science 4, no. 3 (March 2017): 160914. http://dx.doi.org/10.1098/rsos.160914.
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Rapidly mutating pathogens may be able to persist in the population and reach an endemic equilibrium by escaping hosts’ acquired immunity. For such diseases, multiple biological, environmental and population-level mechanisms determine the dynamics of the outbreak, including pathogen's epidemiological traits (e.g. transmissibility, infectious period and duration of immunity), seasonality, interaction with other circulating strains and hosts’ mixing and spatial fragmentation. Here, we study a susceptible-infected-recovered-susceptible model on a metapopulation where individuals are distributed in sub-populations connected via a network of mobility flows. Through extensive numerical simulations, we explore the phase space of pathogen's persistence and map the dynamical regimes of the pathogen following emergence. Our results show that spatial fragmentation and mobility play a key role in the persistence of the disease whose maximum is reached at intermediate mobility values. We describe the occurrence of different phenomena including local extinction and emergence of epidemic waves, and assess the conditions for large-scale spreading. Findings are highlighted in reference to previous studies and to real scenarios. Our work uncovers the crucial role of hosts’ mobility on the ecological dynamics of rapidly mutating pathogens, opening the path for further studies on disease ecology in the presence of a complex and heterogeneous environment.
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OLIVER, S. P., M. J. LEWIS, T. L. INGLE, B. E. GILLESPIE, K. R. MATTHEWS, and H. H. DOWLEN. "Premilking Teat Disinfection for the Prevention of Environmental Pathogen Intramammary Infections." Journal of Food Protection 56, no. 10 (October 1, 1993): 852–55. http://dx.doi.org/10.4315/0362-028x-56.10.852.
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A natural exposure study was conducted for 14 months to evaluate efficacy of 0.25% iodine premilking teat disinfectant for the prevention of new intramammary infections. Predipping was compared with a negative control using a split-udder experimental design. All teats were dipped after milking with the same teat dip. Most new major pathogen intramammary infections resulted from Streptococcus species, primarily Streptococcus uberis and Streptococcus dysgalactiae, and from gram-negative bacteria, primarily Escherichia coli. New infections by gram-negative bacteria were significantly lower in quarters with teats predipped and postdipped than in quarters with teats postdipped only. Percentage of quarters newly infected by major mastitis pathogens was 48.6% lower in quarters with teats predipped and postdipped than in quarters with teats postdipped only. Statistical differences in incidence of clinical mastitis between treatment groups were not observed. Predipping and postdipping was no more effective against Staphylococcus species and Corynebacterium bovis than postdipping only. These data suggest that pre- and postdipping with the test product was more effective against major pathogens than postdipping only and provide additional evidence that premilking teat disinfection is an effective management procedure for prevention of environmental pathogen intramammary infections.
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Boxall, Alistair, Anthony Hardy, Sabine Beulke, Tatiana Boucard, Laura Burgin, Peter Falloon, Philip Haygarth, et al. "Impacts of climate change on indirect human exposure to pathogens and chemicals from agriculture." Ciência & Saúde Coletiva 15, no. 3 (May 2010): 743–56. http://dx.doi.org/10.1590/s1413-81232010000300017.
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Climate change is likely to affect the nature of pathogens/ chemicals in the environment and their fate and transport. We assess the implications of climate change for changes in human exposures to pathogens/chemicals in agricultural systems in the UK and discuss the effects on health impacts, using expert input and literature on climate change; health effects from exposure to pathogens/chemicals arising from agriculture; inputs of chemicals/pathogens to agricultural systems; and human exposure pathways for pathogens/chemicals in agricultural systems. We established the evidence base for health effects of chemicals/pathogens in the agricultural environment; determined the potential implications of climate change on chemical/pathogen inputs in agricultural systems; and explored the effects of climate change on environmental transport and fate of various contaminants. We merged data to assess the implications of climate change in terms of indirect human exposure to pathogens/chemicals in agricultural systems, and defined recommendations on future research and policy changes to manage adverse increases in risks.
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Blackburn, Jason K., Holly H. Ganz, José Miguel Ponciano, Wendy C. Turner, Sadie J. Ryan, Pauline Kamath, Carrie Cizauskas, et al. "Modeling R0 for Pathogens with Environmental Transmission: Animal Movements, Pathogen Populations, and Local Infectious Zones." International Journal of Environmental Research and Public Health 16, no. 6 (March 17, 2019): 954. http://dx.doi.org/10.3390/ijerph16060954.
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How a disease is transmitted affects our ability to determine R0, the average number of new cases caused by an infectious host at the onset of an epidemic. R0 becomes progressively more difficult to compute as transmission varies from directly transmitted diseases to diseases that are vector-borne to environmentally transmitted diseases. Pathogens responsible for diseases with environmental transmission are typically maintained in environmental reservoirs that exhibit a complex spatial distribution of local infectious zones (LIZs). Understanding host encounters with LIZs and pathogen persistence within LIZs is required for an accurate R0 and modeling these contacts requires an integrated geospatial and dynamical systems approach. Here we review how interactions between host and pathogen populations and environmental reservoirs are driven by landscape-level variables, and synthesize the quantitative framework needed to formulate outbreak response and disease control.
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Mahon, Andrew R., Dean J. Horton, Deric R. Learman, Lucas R. Nathan, and Christopher L. Jerde. "Investigating diversity of pathogenic microbes in commercial bait trade water." PeerJ 6 (August 23, 2018): e5468. http://dx.doi.org/10.7717/peerj.5468.
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The recreational bait trade is a potential pathway for pathogen introduction and spread when anglers dump bait shop sourced water into aquatic systems. Despite this possibility, and previous recognition of the importance of the bait trade in the spread of aquatic invasive species (AIS), to date there has been no region wide survey documenting pathogens in retail bait shops. In this study, we analyzed 96 environmental DNA samples from retail bait shops around the Great Lakes region to identify pathogens, targeting the V4 hypervariable region of the 16S rRNA gene. Additionally, we used samples from one site in Lake Michigan as a comparison to pathogen diversity and abundance in natural aquatic systems. Our results identified nine different groups of pathogens in the bait shop samples, including those that pose risks to both humans and fish species. Compared to wild sourced samples, the bait shops had higher relative abundance and greater taxonomic diversity. These findings suggest that the bait trade represents a potentially important pathway that could introduce and spread pathogens throughout the Great Lakes region. Improving pathogen screening and angler outreach should be used in combination to aid in preventing the future spread of high risk pathogens.
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Gerba, C. P., I. L. Pepper, and L. F. Whitehead. "A risk assessment of emerging pathogens of concern in the land application of biosolids." Water Science and Technology 46, no. 10 (November 1, 2002): 225–30. http://dx.doi.org/10.2166/wst.2002.0338.
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Since the development of the United States Environmental Protection Agency's 503 biosolids Rule, which includes treatment requirements to reduce the threat of pathogen transmission, many new pathogens have been recognized which could be transmitted by biosolids. A risk analysis was performed to assess which emerging pathogens would be most likely to survive treatments required for Class B biosolids before land application. The literature was reviewed on the resistance of emerging pathogens to temperature and other environmental factors to assess their probability of surviving various biosolids treatment processes. In addition existing information on occurrence in biosolids and dose response models for each pathogen was reviewed. It was concluded that adenoviruses and hepatitis A virus are the most thermally resistant viruses and can survive for prolonged periods in the environment. The protozoan parasites microsporidia and Cyclospora were unlikely to survive the temperatures achieved in anaerobic digestion and do not survive well under low moisture conditions. A risk model was used to assess the risk of infection and illness from enteric viruses after application of class B biosolids.
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Collinet-Adler, Stefan, Sudhir Babji, Mark Francis, Deepthi Kattula, Prasanna Samuel Premkumar, Rajiv Sarkar, Venkat Ragava Mohan, et al. "Environmental Factors Associated with High Fly Densities and Diarrhea in Vellore, India." Applied and Environmental Microbiology 81, no. 17 (June 26, 2015): 6053–58. http://dx.doi.org/10.1128/aem.01236-15.
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ABSTRACTDiarrhea causes significant morbidity and mortality in Indian children under 5 years of age. Flies carry enteric pathogens and may mediate foodborne infections. In this study, we characterized fly densities as a determinant of infectious diarrhea in a longitudinal cohort of 160 urban and 80 rural households with 1,274 individuals (27% under 5 years of age) in Vellore, India. Household questionnaires on living conditions were completed at enrollment. Fly abundance was measured during the wet and dry seasons using fly ribbons placed in kitchens. PCRs for enteric bacteria, viruses, and protozoa were performed on 60 fly samples. Forty-three (72%) fly samples were positive for the following pathogens: norovirus (50%),Salmonellaspp. (46.7%), rotavirus (6.7%), andEscherichia coli(6.7%). Ninety-one episodes of diarrhea occurred (89% in children under 5 years of age). Stool pathogens isolated in 24 of 77 (31%) samples includedE. coli,Shigellaspp.,Vibriospp.,Giardia,Cryptosporidium, and rotavirus. Multivariate log-linear models were used to explore the relationships between diarrhea and fly densities, controlling for demographics, hygiene, and human-animal interactions. Fly abundance was 6 times higher in rural than urban sites (P< 0.0001). Disposal of garbage close to homes and rural living were significant risk factors for high fly densities. The presence of latrines was protective against high fly densities and diarrhea. The adjusted relative risks of diarrheal episodes and duration of diarrhea, associated with fly density at the 75th percentile, were 1.18 (95% confidence interval [CI], 1.03 to 1.34) and 1.15 (95% CI, 1.02 to 1.29), respectively. Flies harbored enteric pathogens, including norovirus, a poorly documented pathogen on flies.
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Vazquez, Diego S., Hanna M. Schilbert, and Veronica I. Dodero. "Molecular and Structural Parallels between Gluten Pathogenic Peptides and Bacterial-Derived Proteins by Bioinformatics Analysis." International Journal of Molecular Sciences 22, no. 17 (August 27, 2021): 9278. http://dx.doi.org/10.3390/ijms22179278.
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Gluten-related disorders (GRDs) are a group of diseases that involve the activation of the immune system triggered by the ingestion of gluten, with a worldwide prevalence of 5%. Among them, Celiac disease (CeD) is a T-cell-mediated autoimmune disease causing a plethora of symptoms from diarrhea and malabsorption to lymphoma. Even though GRDs have been intensively studied, the environmental triggers promoting the diverse reactions to gluten proteins in susceptible individuals remain elusive. It has been proposed that pathogens could act as disease-causing environmental triggers of CeD by molecular mimicry mechanisms. Additionally, it could also be possible that unrecognized molecular, structural, and physical parallels between gluten and pathogens have a relevant role. Herein, we report sequence, structural and physical similarities of the two most relevant gluten peptides, the 33-mer and p31-43 gliadin peptides, with bacterial pathogens using bioinformatics going beyond the molecular mimicry hypothesis. First, a stringent BLASTp search using the two gliadin peptides identified high sequence similarity regions within pathogen-derived proteins, e.g., extracellular proteins from Streptococcus pneumoniae and Granulicatella sp. Second, molecular dynamics calculations of an updated α-2-gliadin model revealed close spatial localization and solvent-exposure of the 33-mer and p31-43 peptide, which was compared with the pathogen-related proteins by homology models and localization predictors. We found putative functions of the identified pathogen-derived sequence by identifying T-cell epitopes and SH3/WW-binding domains. Finally, shape and size parallels between the pathogens and the superstructures of gliadin peptides gave rise to novel hypotheses about activation of innate immunity and dysbiosis. Based on our structural findings and the similarities with the bacterial pathogens, evidence emerges that these pathologically relevant gluten-derived peptides could behave as non-replicating pathogens opening new research questions in the interface of innate immunity, microbiome, and food research.
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Stukenbrock, Eva H. "The Role of Hybridization in the Evolution and Emergence of New Fungal Plant Pathogens." Phytopathology® 106, no. 2 (February 2016): 104–12. http://dx.doi.org/10.1094/phyto-08-15-0184-rvw.
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Hybridization in fungi has recently been recognized as a major force in the generation of new fungal plant pathogens. These include the grass pathogen Zymoseptoria pseudotritici and the powdery mildew pathogen Blumeria graminis triticale of triticale. Hybridization also plays an important role in the transfer of genetic material between species. This process is termed introgressive hybridization and involves extensive backcrossing between hybrid and the parental species. Introgressive hybridization has contributed substantially to the successful spread of plant pathogens such as Ophiostoma ulmi and O. novo-ulmi, the causal agents of Dutch elm disease, and other tree pathogens such as the rust pathogen Melampsora. Hybridization occurs more readily between species that have previously not coexisted, so-called allopatric species. Reproductive barriers between allopatric species are likely to be more permissive allowing interspecific mating to occur. The bringing together of allopatric species of plant pathogens by global agricultural trade consequently increases the potential for hybridization between pathogen species. In light of global environmental changes, agricultural development, and the facilitated long-distance spread of fungal plant pathogens, hybridization should be considered an important mechanism whereby new pathogens may emerge. Recent studies have gained insight into the genetics and biology of fungal hybrids. Here I summarize current knowledge about hybrid speciation and introgressive hybridization. I propose that future studies will benefit greatly from the availability of large genome data sets and that genome data provide a powerful resource in combination with experimental approaches for analyses of hybrid species.
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Arruda, Andréia Gonçalves, Steve Tousignant, Juan Sanhueza, Carles Vilalta, Zvonimir Poljak, Montserrat Torremorell, Carmen Alonso, and Cesar A. Corzo. "Aerosol Detection and Transmission of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV): What Is the Evidence, and What Are the Knowledge Gaps?" Viruses 11, no. 8 (August 3, 2019): 712. http://dx.doi.org/10.3390/v11080712.
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In human and veterinary medicine, there have been multiple reports of pathogens being airborne under experimental and field conditions, highlighting the importance of this transmission route. These studies shed light on different aspects related to airborne transmission such as the capability of pathogens becoming airborne, the ability of pathogens to remain infectious while airborne, the role played by environmental conditions in pathogen dissemination, and pathogen strain as an interfering factor in airborne transmission. Data showing that airborne pathogens originating from an infectious individual or population can infect susceptible hosts are scarce, especially under field conditions. Furthermore, even though disease outbreak investigations have generated important information identifying potential ports of entry of pathogens into populations, these investigations do not necessarily yield clear answers on mechanisms by which pathogens have been introduced into populations. In swine, the aerosol transmission route gained popularity during the late 1990’s as suspicions of airborne transmission of porcine reproductive and respiratory syndrome virus (PRRSV) were growing. Several studies were conducted within the last 15 years contributing to the understanding of this transmission route; however, questions still remain. This paper reviews the current knowledge and identifies knowledge gaps related to PRRSV airborne transmission.
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TODD, EWEN C. D., JUDY D. GREIG, CHARLES A. BARTLESON, and BARRY S. MICHAELS. "Outbreaks Where Food Workers Have Been Implicated in the Spread of Foodborne Disease. Part 6. Transmission and Survival of Pathogens in the Food Processing and Preparation Environment." Journal of Food Protection 72, no. 1 (January 1, 2009): 202–19. http://dx.doi.org/10.4315/0362-028x-72.1.202.
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This article, the sixth in a series reviewing the role of food workers in foodborne outbreaks, describes the source and means of pathogen transfer. The transmission and survival of enteric pathogens in the food processing and preparation environment through human and raw food sources is reviewed, with the main objective of providing information critical to the reduction of illness due to foodborne outbreaks. Pathogens in the food preparation area can originate from infected food workers, raw foods, or other environmental sources. These pathogens can then spread within food preparation or processing facilities through sometimes complex pathways and may infect one or more workers or the consumer of foods processed or prepared by these infected workers. The most frequent means of worker contamination is the fecal-oral route, and study results have indicated that toilet paper may not stop transmission of pathogens to hands. However, contact with raw foods of animal origin, worker aerosols (from sneezes), vomitus, and exposed hand lesions also have been associated with outbreaks. Transfer of pathogens has been documented through contaminated fabrics and carpets, rings, currency, skin surfaces, dust, and aerosols and though person-to-person transmission. Results of experiments on pathogen survival have indicated that transmission depends on the species, the inoculum delivery route, the contact surface type, the duration and temperature of exposure, and the relative humidity. Generally, viruses and encysted parasites are more resistant than enteric bacteria to adverse environmental conditions, but all pathogens can survive long enough for transfer from a contaminated worker to food, food contact surfaces, or fellow workers.
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Wang, Xiaoyu, Lingyao Kong, Pengfei Zhi, and Cheng Chang. "Update on Cuticular Wax Biosynthesis and Its Roles in Plant Disease Resistance." International Journal of Molecular Sciences 21, no. 15 (August 1, 2020): 5514. http://dx.doi.org/10.3390/ijms21155514.
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The aerial surface of higher plants is covered by a hydrophobic layer of cuticular waxes to protect plant tissues against enormous environmental challenges including the infection of various pathogens. As the first contact site between plants and pathogens, the layer of cuticular waxes could function as a plant physical barrier that limits the entry of pathogens, acts as a reservoir of signals to trigger plant defense responses, and even gives cues exploited by pathogens to initiate their infection processes. Past decades have seen unprecedented proceedings in understanding the molecular mechanisms underlying the biosynthesis of plant cuticular waxes and their functions regulating plant–pathogen interactions. In this review, we summarized the recent progress in the molecular biology of cuticular wax biosynthesis and highlighted its multiple roles in plant disease resistance against bacterial, fungal, and insect pathogens.
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Cook, J. L. "Nontuberculous mycobacteria: opportunistic environmental pathogens for predisposed hosts." British Medical Bulletin 96, no. 1 (October 25, 2010): 45–59. http://dx.doi.org/10.1093/bmb/ldq035.
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Julian, Timothy R., and Kellogg J. Schwab. "Challenges in environmental detection of human viral pathogens." Current Opinion in Virology 2, no. 1 (February 2012): 78–83. http://dx.doi.org/10.1016/j.coviro.2011.10.027.
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Sutton, J. C., and P. D. Hildebrand. "Environmental water in relation toPeronospora destructorand related pathogens." Canadian Journal of Plant Pathology 7, no. 3 (September 1985): 323–30. http://dx.doi.org/10.1080/07060668509501699.
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Ghosh, Shyamasree. "Environmental pollutants, pathogens and immune system in earthworms." Environmental Science and Pollution Research 25, no. 7 (January 11, 2018): 6196–208. http://dx.doi.org/10.1007/s11356-017-1167-8.
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Anderson, Peter D., and Gyula Bokor. "Bioterrorism: Pathogens as Weapons." Journal of Pharmacy Practice 25, no. 5 (September 25, 2012): 521–29. http://dx.doi.org/10.1177/0897190012456366.
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Biowarfare has been used for centuries. The use of biological weapons in terrorism remains a threat. Biological weapons include infectious agents (pathogens) and toxins. The most devastating bioterrorism scenario would be the airborne dispersal of pathogens over a concentrated population area. Characteristics that make a specific pathogen a high-risk for bioterrorism include a low infective dose, ability to be aerosolized, high contagiousness, and survival in a variety of environmental conditions. The most dangerous potential bioterrorism agents include the microorganisms that produce anthrax, plague, tularemia, and smallpox. Other diseases of interest to bioterrorism include brucellosis, glanders, melioidosis, Q fever, and viral encephalitis. Food safety and water safety threats are another area of concern.
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Timmusk, Salme, Eviatar Nevo, Fantaye Ayele, Steffen Noe, and Ülo Niinemets. "Fighting Fusarium Pathogens in the Era of Climate Change: A Conceptual Approach." Pathogens 9, no. 6 (May 28, 2020): 419. http://dx.doi.org/10.3390/pathogens9060419.
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Fusarium head blight (FHB) caused by Fusarium pathogens is one of the most devastating fungal diseases of small grain cereals worldwide, substantially reducing yield quality and food safety. Its severity is increasing due to the climate change caused by weather fluctuations. Intensive research on FHB control methods has been initiated more than a decade ago. Since then, the environment has been rapidly changing at regional to global scales due to increasing anthropogenic emissions enhanced fertilizer application and substantial changes in land use. It is known that environmental factors affect both the pathogen virulence as well as plant resistance mechanisms. Changes in CO2 concentration, temperature, and water availability can have positive, neutral, or negative effects on pathogen spread depending on the environmental optima of the pathosystem. Hence, there is a need for studies of plant–pathogen interactions in current and future environmental context. Long-term monitoring data are needed in order to understand the complex nature of plants and its microbiome interactions. We suggest an holobiotic approach, integrating plant phyllosphere microbiome research on the ecological background. This will enable the development of efficient strategies based on ecological know-how to fight Fusarium pathogens and maintain sustainable agricultural systems.
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Malkin, A. J., M. Plomp, T. J. Leighton, A. McPherson, and K. E. Wheeler. "Unraveling the Architecture and Structural Dynamics of Pathogens by High-Resolution in vitro Atomic Force Microscopy." Microscopy and Microanalysis 11, S03 (December 2005): 32–35. http://dx.doi.org/10.1017/s1431927605050828.
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Progress in structural biology very much depends upon the development of new high-resolution techniques and tools. Despite decades of study of viruses, bacteria and bacterial spores and their pressing importance in human medicine and biodefense, many of their structural properties are poorly understood. Thus, characterization and understanding of the architecture of protein surface and internal structures of pathogens is critical to elucidating mechanisms of disease, immune response, physicochemical properties, environmental resistance and development of countermeasures against bioterrorist agents. Furthermore, even though complete genome sequences are available for various pathogens, the structure-function relationships are not understood. Because of their lack of symmetry and heterogeneity, large human pathogens are often refractory to X-ray crystallographic analysis or reconstruction by cryo-electron microscopy (cryo-EM). An alternative high-resolution method to examine native structure of pathogens is atomic force microscopy (AFM), which allows direct visualization of macromolecular assemblies at near-molecular resolution. The capability to image single pathogen surfaces at nanometer scale in vitro would profoundly impact mechanistic and structural studies of Progress in structural biology very much depends upon the development of new high-resolution techniques and tools. Despite decades of study of viruses, bacteria and bacterial spores and their pressing importance in human medicine and biodefense, many of their structural properties are poorly understood. Thus, characterization and understanding of the architecture of protein surface and internal structures of pathogens is critical to elucidating mechanisms of disease, immune response, physicochemical properties, environmental resistance and development of countermeasures against bioterrorist agents. Furthermore, even though complete genome sequences are available for various pathogens, the structure-function relationships are not understood. Because of their lack of symmetry and heterogeneity, large human pathogens are often refractory to X-ray crystallographic analysis or reconstruction by cryo-electron microscopy (cryo-EM). An alternative high-resolution method to examine native structure of pathogens is atomic force microscopy (AFM), which allows direct visualization of macromolecular assemblies at near-molecular resolution. The capability to image single pathogen surfaces at nanometer scale in vitro would profoundly impact mechanistic and structural studies of pathogenesis, immunobiology, specific cellular processes, environmental dynamics and biotransformation.
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Benson, Lee, Ross S. Davidson, Darren M. Green, Andrew Hoyle, Mike R. Hutchings, and Glenn Marion. "When and why direct transmission models can be used for environmentally persistent pathogens." PLOS Computational Biology 17, no. 12 (December 1, 2021): e1009652. http://dx.doi.org/10.1371/journal.pcbi.1009652.
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Variants of the susceptible-infected-removed (SIR) model of Kermack & McKendrick (1927) enjoy wide application in epidemiology, offering simple yet powerful inferential and predictive tools in the study of diverse infectious diseases across human, animal and plant populations. Direct transmission models (DTM) are a subset of these that treat the processes of disease transmission as comprising a series of discrete instantaneous events. Infections transmitted indirectly by persistent environmental pathogens, however, are examples where a DTM description might fail and are perhaps better described by models that comprise explicit environmental transmission routes, so-called environmental transmission models (ETM). In this paper we discuss the stochastic susceptible-exposed-infected-removed (SEIR) DTM and susceptible-exposed-infected-removed-pathogen (SEIR-P) ETM and we show that the former is the timescale separation limit of the latter, with ETM host-disease dynamics increasingly resembling those of a DTM when the pathogen’s characteristic timescale is shortened, relative to that of the host population. Using graphical posterior predictive checks (GPPC), we investigate the validity of the SEIR model when fitted to simulated SEIR-P host infection and removal times. Such analyses demonstrate how, in many cases, the SEIR model is robust to departure from direct transmission. Finally, we present a case study of white spot disease (WSD) in penaeid shrimp with rates of environmental transmission and pathogen decay (SEIR-P model parameters) estimated using published results of experiments. Using SEIR and SEIR-P simulations of a hypothetical WSD outbreak management scenario, we demonstrate how relative shortening of the pathogen timescale comes about in practice. With atttempts to remove diseased shrimp from the population every 24h, we see SEIR and SEIR-P model outputs closely conincide. However, when removals are 6-hourly, the two models’ mean outputs diverge, with distinct predictions of outbreak size and duration.
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Stenlid, Jan, and Jonàs Oliva. "Phenotypic interactions between tree hosts and invasive forest pathogens in the light of globalization and climate change." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1709 (December 5, 2016): 20150455. http://dx.doi.org/10.1098/rstb.2015.0455.
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Invasive pathogens can cause considerable damage to forest ecosystems. Lack of coevolution is generally thought to enable invasive pathogens to bypass the defence and/or recognition systems in the host. Although mostly true, this argument fails to predict intermittent outcomes in space and time, underlining the need to include the roles of the environment and the phenotype in host–pathogen interactions when predicting disease impacts. We emphasize the need to consider host–tree imbalances from a phenotypic perspective, considering the lack of coevolutionary and evolutionary history with the pathogen and the environment, respectively. We describe how phenotypic plasticity and plastic responses to environmental shifts may become maladaptive when hosts are faced with novel pathogens. The lack of host–pathogen and environmental coevolution are aligned with two global processes currently driving forest damage: globalization and climate change, respectively. We suggest that globalization and climate change act synergistically, increasing the chances of both genotypic and phenotypic imbalances. Short moves on the same continent are more likely to be in balance than if the move is from another part of the world. We use Gremmeniella abietina outbreaks in Sweden to exemplify how host–pathogen phenotypic interactions can help to predict the impacts of specific invasive and emergent diseases. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’.
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Peterson, P. D., and C. L. Campbell. "Prevalence and Ecological Association of Foliar Pathogens of Cucumber in North Carolina, 1996-1998." Plant Disease 86, no. 10 (October 2002): 1094–100. http://dx.doi.org/10.1094/pdis.2002.86.10.1094.
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During the fall growing seasons of 1996-98, 5,400 leaves exhibiting leaf spots were collected from cucumber (Cucumis sativus L.) fields and microscopically examined to identify the organisms associated with these symptoms. Five fungal pathogens were associated with leaf lesions: Alternaria cucumerina, Colletotrichum orbiculare, Corynespora cassiicola, Didymella bryoniae, and Pseudoperonospora cubensis; D. bryoniae and C. orbiculare occurred most frequently. When pathogens were paired on five or more leaves, associations between pathogen pairs were tested for independence via a 2-by-2 contingency table χ2 analysis. In all, 66 two-way pathogen associations were tested. Of these, 39 associations were negative (occurred together less often than expected at random), 1 was positive (occurred together more often than expected at random), and, in 16 cases, the pathogens were not associated. An association between C. orbiculare and D. bryoniae occurred 24 times and, each time, the relationship was negative. This result, combined with different environmental requirements for infection, suggests that these pathogens either occupy different niches in the plant canopy or are antagonistic. No relationship between the cultivars grown or the fungicides applied and the pathogens isolated from specific field sites was found. Information on the dominant pathogens responsible for leaf spot epidemics in North Carolina's cucumber fields will be useful to target breeding and disease control strategies.
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Chale-Matsau, J. R. B., and H. G. Snyman. "The survival of pathogens in soil treated with wastewater sludge and in potatoes grown in such soil." Water Science and Technology 54, no. 5 (September 1, 2006): 163–68. http://dx.doi.org/10.2166/wst.2006.559.
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The prevalence of pathogens on potatoes (Solanum tuberosum) grown in soil amended with a pathogen rich wastewater sludge was investigated. Bacteria of the family Enterobacteriaceae are important pathogens causing intestinal and systemic illness of humans and other animals. Type B sludge was used. Sludges investigated are the high metal and the low metal sludges. Microorganisms in the sludge-amended soil were using culture-based technique. Salmonella and E. coli were observed in tested soil samples. No microorganisms were isolated from control samples taken throughout the process of the experiment. At harvest time, some of the potato samples from LMS soil were contaminated. These potatoes were subjected to further investigation using molecular techniques (polymerase chain reaction) with fD1 and rP2 as primers. Organisms identified from the sequenced potato peel samples with the BLAST search tool included Enterobacter agglomerans (Pantoea agglomerans), several Buttiauxella spp., Pectobacterium spp., Erwinia spp. and a few Pantoea spp. Other than the E. agglomerans, which is commonly found in the gut and upper respiratory tract of humans and in the environment, all the other species identified were found to be mainly either plant or soil pathogens. The E. agglomerans are not primary pathogens but secondary opportunistic pathogens particularly in immuno-compromised individuals. These results suggest that growing high risk crops using wastewater sludge contaminated soil may lead to limited infestation of produce with primary pathogens. It appears that the use of HMS due to early pathogen die-off provides less risk of infection than the LMS. However, proper treatment of wastewater sludge to reduce pathogen load is essential prior to its use as soil conditioner.
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NORMAN, R. A., A. J. WORTON, and L. GILBERT. "Past and future perspectives on mathematical models of tick-borne pathogens." Parasitology 143, no. 7 (December 18, 2015): 850–59. http://dx.doi.org/10.1017/s0031182015001523.
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SUMMARYTicks are vectors of pathogens which are important both with respect to human health and economically. They have a complex life cycle requiring several blood meals throughout their life. These blood meals take place on different individual hosts and potentially on different host species. Their life cycle is also dependent on environmental conditions such as the temperature and habitat type. Mathematical models have been used for the more than 30 years to help us understand how tick dynamics are dependent on these environmental factors and host availability. In this paper, we review models of tick dynamics and summarize the main results. This summary is split into two parts, one which looks at tick dynamics and one which looks at tick-borne pathogens. In general, the models of tick dynamics are used to determine when the peak in tick densities is likely to occur in the year and how that changes with environmental conditions. The models of tick-borne pathogens focus more on the conditions under which the pathogen can persist and how host population densities might be manipulated to control these pathogens. In the final section of the paper, we identify gaps in the current knowledge and future modelling approaches. These include spatial models linked to environmental information and Geographic Information System maps, and development of new modelling techniques which model tick densities per host more explicitly.
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Krediet, Cory J., Kim B. Ritchie, Matthew Cohen, Erin K. Lipp, Kathryn Patterson Sutherland, and Max Teplitski. "Utilization of Mucus from the Coral Acropora palmata by the Pathogen Serratia marcescens and by Environmental and Coral Commensal Bacteria." Applied and Environmental Microbiology 75, no. 12 (April 24, 2009): 3851–58. http://dx.doi.org/10.1128/aem.00457-09.
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ABSTRACT In recent years, diseases of corals caused by opportunistic pathogens have become widespread. How opportunistic pathogens establish on coral surfaces, interact with native microbiota, and cause disease is not yet clear. This study compared the utilization of coral mucus by coral-associated commensal bacteria (“Photobacterium mandapamensis” and Halomonas meridiana) and by opportunistic Serratia marcescens pathogens. S. marcescens PDL100 (a pathogen associated with white pox disease of Acroporid corals) grew to higher population densities on components of mucus from the host coral. In an in vitro coculture on mucus from Acropora palmata, S. marcescens PDL100 isolates outgrew coral isolates. The white pox pathogen did not differ from other bacteria in growth on mucus from a nonhost coral, Montastraea faveolata. The ability of S. marcescens to cause disease in acroporid corals may be due, at least in part, to the ability of strain PDL100 to build to higher population numbers within the mucus surface layer of its acroporid host. During growth on mucus from A. palmata, similar glycosidase activities were present in coral commensal bacteria, in S. marcescens PDL100, and in environmental and human isolates of S. marcescens. The temporal regulation of these activities during growth on mucus, however, was distinct in the isolates. During early stages of growth on mucus, enzymatic activities in S. marcescens PDL100 were most similar to those in coral commensals. After overnight incubation on mucus, enzymatic activities in a white pox pathogen were most similar to those in pathogenic Serratia strains isolated from human mucosal surfaces.
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Reilly, Maureen. "The Case against Land Application of Sewage Sludge Pathogens." Canadian Journal of Infectious Diseases 12, no. 4 (2001): 205–7. http://dx.doi.org/10.1155/2001/183583.
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There is currently a public debate about whether health, agricultural and environmental authorities should continue to allow sewage sludge to be spread on farmland. Some of the concern in the debate is about the pathogen content of sewage sludge. This concern was heightened by the tragedy at Walkerton whereEschericha coli0157:H7 and other pathogens contaminated the drinking water supply of this Ontario town. The Canadian public were reminded how vulnerable they can be to disease when agricultural practices ajoin population centres without adequate health and environmental controls.
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Dutta, Anik, Fanny E. Hartmann, Carolina Sardinha Francisco, Bruce A. McDonald, and Daniel Croll. "Mapping the adaptive landscape of a major agricultural pathogen reveals evolutionary constraints across heterogeneous environments." ISME Journal 15, no. 5 (January 15, 2021): 1402–19. http://dx.doi.org/10.1038/s41396-020-00859-w.
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AbstractThe adaptive potential of pathogens in novel or heterogeneous environments underpins the risk of disease epidemics. Antagonistic pleiotropy or differential resource allocation among life-history traits can constrain pathogen adaptation. However, we lack understanding of how the genetic architecture of individual traits can generate trade-offs. Here, we report a large-scale study based on 145 global strains of the fungal wheat pathogen Zymoseptoria tritici from four continents. We measured 50 life-history traits, including virulence and reproduction on 12 different wheat hosts and growth responses to several abiotic stressors. To elucidate the genetic basis of adaptation, we used genome-wide association mapping coupled with genetic correlation analyses. We show that most traits are governed by polygenic architectures and are highly heritable suggesting that adaptation proceeds mainly through allele frequency shifts at many loci. We identified negative genetic correlations among traits related to host colonization and survival in stressful environments. Such genetic constraints indicate that pleiotropic effects could limit the pathogen’s ability to cause host damage. In contrast, adaptation to abiotic stress factors was likely facilitated by synergistic pleiotropy. Our study illustrates how comprehensive mapping of life-history trait architectures across diverse environments allows to predict evolutionary trajectories of pathogens confronted with environmental perturbations.
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del Pilar Martínez-Diz, María, Marcos Andrés-Sodupe, Mónica Berbegal, Rebeca Bujanda, Emilia Díaz-Losada, and David Gramaje. "Droplet Digital PCR Technology for Detection of Ilyonectria liriodendri from Grapevine Environmental Samples." Plant Disease 104, no. 4 (April 2020): 1144–50. http://dx.doi.org/10.1094/pdis-03-19-0529-re.
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Black-foot disease is one of the most important soilborne diseases affecting planting material in grapevine nurseries and young vineyards. Accurate, early, and specific detection and quantification of black-foot disease causing fungi are essential to alert growers and nurseries to the presence of the pathogens in soil, and to prevent the spread of these pathogens through grapevines using certified pathogen-free planting material and development of resistance. We comparatively assessed the accuracy, efficiency, and specificity of droplet digital PCR (ddPCR) and real-time PCR (qPCR) techniques for the detection and quantification of Ilyonectria liriodendri in bulk and rhizosphere soils, as well as grapevine endorhizosphere. Fungal abundance was not affected by soil-plant fractions. Both techniques showed a high degree of correlation across the samples assessed (R2 = 0.95) with ddPCR being more sensitive to lower target concentrations. Roots of asymptomatic vines were found to be a microbial niche that is inhabited by black-foot disease fungi.
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Fletcher, Stephanie M., Mary-Louise McLaws, and John T. Ellis. "Prevalence of gastrointestinal pathogens in developed and developing countries: systematic review and meta-analysis." Journal of Public Health Research 2, no. 1 (July 16, 2013): 9. http://dx.doi.org/10.4081/jphr.2013.e9.
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Diarrhoeal illness is a leading cause of child mortality and morbidity worldwide. There are no precise or current estimates of the types and prevalence of pathogens associated with diarrheal illnesses in developed and developing settings. This systematic review assessed data from 60 studies published in the English language from five developing regions and developed countries worldwide to provide regional estimates of enteric pathogens affecting children. The random-effect method was used to establish the weighted average prevalence of pathogens in adults and children for each region. Significantly more pathogens were reported by studies from developing regions compared with Organisation for Economic Co-operation and Development countries (P<0.016). The identification rates of pathogens from community based and hospital based studies were similar (58.5% and 58.1% respectively, P<0.619). The overall detection of enteric pathogens in developing countries was higher in adults (74.8%; 95% CI 63.1-83.8%) compared with children (56.7%; 95% CI 53.0-60.4%) (P<0.001). Rotavirus was the most frequently detected pathogen in all regions with the highest rate, 24.8% (95% CI 18.0-33.1%), detected in the developed countries. This systematic review is the first to provide an estimate of the prevalence of enteric pathogens associated with diarrhoeal illnesses in adults and children in developed and developing settings. While pathogen detection rate is greater in developing regions the consistently high prevalence of rotavirus in both developed and developing settings underscores the urgent need for access to rotavirus vaccines. Increased travel between developing and developed countries increases disease risk, and hence developed countries have a vested interest in supporting vaccine accessibility in developing settings.
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Wu, J., S. C. Long, D. Das, and S. M. Dorner. "Are microbial indicators and pathogens correlated? A statistical analysis of 40 years of research." Journal of Water and Health 9, no. 2 (April 25, 2011): 265–78. http://dx.doi.org/10.2166/wh.2011.117.
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Indicator organisms are used to assess public health risk in recreational waters, to highlight periods of challenge to drinking water treatment plants, and to determine the effectiveness of treatment and the quality of distributed water. However, many have questioned their efficacy for indicating pathogen risk. Five hundred and forty cases representing independent indicator–pathogen correlations were obtained from the literature for the period 1970–2009. The data were analyzed to assess factors affecting correlations using a logistic regression model considering indicator classes, pathogen classes, water types, pathogen sources, sample size, the number of samples with pathogens, the detection method, year of publication and statistical methods. Although no single indicator was identified as the most correlated with pathogens, coliphages, F-specific coliphages, Clostridium perfringens, fecal streptococci and total coliforms were more likely than other indicators to be correlated with pathogens. The most important factors in determining correlations between indicator–pathogen pairs were the sample size and the number of samples positive for pathogens. Pathogen sources, detection methods and other variables have little influence on correlations between indicators and pathogens. Results suggest that much of the controversy with regards to indicator and pathogen correlations is the result of studies with insufficient data for assessing correlations.
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Guo, Jianjiang, and Rongbiao Zhang. "Immunomagnetic separation for MEMS-based biosensor of waterborne pathogens detection." Modern Physics Letters B 31, no. 19-21 (July 27, 2017): 1740084. http://dx.doi.org/10.1142/s021798491740084x.
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Rapid isolation and detection of special pathogens present in environmental drinking water is critical for water quality monitoring. Numerical analysis and experimental investigations on immunomagnetic capture and isolation of waterborne pathogens with magnetic nanoparticles (MNPs) in microfluidic channel are performed. A finite-element COMSOL-based model is established to demonstrate the novel method of on-chip capturing pathogens using MNPs together with periodic pulse magnetic field. Simulation results determine the optimum magnetic pole current and switching frequency for magnetic separation. With the magnetic isolation experiment platform built up, as a pathogen example of Escherichia coli O157:H7, the performance of the method is experimentally verified. Both numerical and experimental results are found to agree reasonably well. Results of these investigations show that the capture efficiency of the immunomagnetic separation method is more than 92%, which could be encouraging for the design and optimization of MEMS-based biosensor of waterborne pathogen detection.
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Twitchell, Katherine T., and Joy E. Wachs. "Bloodborne Pathogens." AAOHN Journal 51, no. 1 (January 2003): 38–47. http://dx.doi.org/10.1177/216507990305100109.
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Tomoshevich, M. A., D. Belomesyatseva, E. V. Banaev, I. G. Vorob’eva, and T. Shabashova. "Comparative Analysis of Foliar Diseases of Some Native and Non-Native Tree Species in Belarus and Siberia." Contemporary Problems of Ecology 16, no. 2 (April 2023): 217–29. http://dx.doi.org/10.1134/s1995425523020166.
Full textAbstract:
Abstract Urban green spaces are known to be subjected to additional anthropogenic stress. Using native plants in monoculture, i.e., planting trees of the same species, may favour disease outbreaks and plant death. Non-native plants to be used in large cities for creating sustainable plantations are being searched for worldwide. Meanwhile, it is necessary to control plant pathogens in the variable conditions of the region and natural habitat. In Siberian cities, non-native European trees are used, and non-native Siberian plants are introduced in Belarus. This article reports long-term observations of foliar fungal pathogens attacking 21 woody plants (19 European, 2 Siberian) in Siberian and Belarusian cities. In both regions, 48 leaf fungal pathogens were detected, with powdery mildew fungi predominating in Belarus and leaf spotting fungi prevailing in Siberia. In both research regions, the greatest number of fungal species was found on Syringa vulgaris L. In Siberia, many pathogens were found on the non-native European plant Berberis vulgaris (9 species) and native plant Caragana arborescens Lam. (8 species). We have not detected the pathogens on European plants: Acer campestre L., Acer platanoides L., Euonymus europaeus L., Lonicera caprifolium L. in urban green areas in Siberia, while we have identified one to four foliar fungal pathogens on these plants in Belarus. To sum up: more pathogens were found on native plants in Siberia and Belarus; some leaf pathogen species (Sawadaea tulasnei (Fuckel) Homma, Erysiphe alphitoides (Griffon & Maubl.) U. Braun & S. Takam., Cladosporium syringae (Oudem.) Montem., Erysiphe syringae Schwein., Erysiphe palczewskii (Jacz.) U. Braun & S. Takam.) followed their host plants (Acer tataricum L., Syringa vulgaris L., Caragana arborescens Lam.) when introduced into new areas; and some local pathogens were also observed to spread to the non-native plants of closely related species.