Articoli di riviste: "Intra-species transmission"

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Roach, Shanley N., e Ryan A. Langlois. "Intra- and Cross-Species Transmission of Astroviruses". Viruses 13, n. 6 (11 giugno 2021): 1127. http://dx.doi.org/10.3390/v13061127.

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Astroviruses are non-enveloped, single-stranded RNA viruses that infect mammalian and avian species. In humans, astrovirus infections are one of the most common causes of gastroenteritis in children. Infection has also been linked to serious neurological complications, especially in immunocompromised individuals. More extensive disease has also been characterized in non-human mammalian and avian species. To date, astroviruses have been detected in over 80 different avian and mammalian hosts. As the number of hosts continues to rise, the need to understand how astroviruses transmit within a given species as well as to new host species becomes increasingly important. Here, we review the current understanding of astrovirus transmission, the factors that influence viral spread, and the potential for cross-species transmission. Additionally, we highlight the current gaps in knowledge and areas of future research that will be key to understanding astrovirus transmission and zoonotic potential.

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Singsit, C., e R. E. Veilleux. "Intra- and interspecific transmission of androgenetic competence in diploid potato species". Euphytica 43, n. 1-2 (settembre 1989): 105–12. http://dx.doi.org/10.1007/bf00037902.

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Tabachnick, Walter. "Nature, Nurture and Evolution of Intra-Species Variation in Mosquito Arbovirus Transmission Competence". International Journal of Environmental Research and Public Health 10, n. 1 (11 gennaio 2013): 249–77. http://dx.doi.org/10.3390/ijerph10010249.

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Borucki, Monica K., Haiyin Chen-Harris, Victoria Lao, Gilda Vanier, Debra A. Wadford, Sharon Messenger e Jonathan E. Allen. "Ultra-Deep Sequencing of Intra-host Rabies Virus Populations during Cross-species Transmission". PLoS Neglected Tropical Diseases 7, n. 11 (21 novembre 2013): e2555. http://dx.doi.org/10.1371/journal.pntd.0002555.

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Gutiérrez-López, Rafael, Josué Martínez-de la Puente, Laura Gangoso, Ramón Soriguer e Jordi Figuerola. "Plasmodium transmission differs between mosquito species and parasite lineages". Parasitology 147, n. 4 (22 gennaio 2020): 441–47. http://dx.doi.org/10.1017/s0031182020000062.

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AbstractFactors such as the particular combination of parasite–mosquito species, their co-evolutionary history and the host's parasite load greatly affect parasite transmission. However, the importance of these factors in the epidemiology of mosquito-borne parasites, such as avian malaria parasites, is largely unknown. Here, we assessed the competence of two mosquito species [Culex pipiens and Aedes (Ochlerotatus) caspius], for the transmission of four avian Plasmodium lineages (Plasmodium relictum SGS1 and GRW11 and Plasmodium cathemerium-related lineages COLL1 and PADOM01) naturally infecting wild house sparrows. We assessed the effects of parasite identity and parasite load on Plasmodium transmission risk through its effects on the transmission rate and mosquito survival. We found that Cx. pipiens was able to transmit the four Plasmodium lineages, while Ae. caspius was unable to transmit any of them. However, Cx. pipiens mosquitoes fed on birds infected by P. relictum showed a lower survival and transmission rate than those fed on birds infected by parasites related to P. cathemerium. Non-significant associations were found with the host–parasite load. Our results confirm the existence of inter- and intra-specific differences in the ability of Plasmodium lineages to develop in mosquito species and their effects on the survival of mosquitoes that result in important differences in the transmission risk of the different avian malaria parasite lineages studied.

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Bonnaud, Emilie M., Cécile Troupin, Laurent Dacheux, Edward C. Holmes, Elodie Monchatre-Leroy, Marion Tanguy, Christiane Bouchier, Florence Cliquet, Jacques Barrat e Hervé Bourhy. "Comparison of intra- and inter-host genetic diversity in rabies virus during experimental cross-species transmission". PLOS Pathogens 15, n. 6 (20 giugno 2019): e1007799. http://dx.doi.org/10.1371/journal.ppat.1007799.

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Mendez, Armando D., e Nathaniel J. Hall. "Evaluating and re-evaluating intra- and inter-species social transmission of food preferences in domestic dogs". Behavioural Processes 191 (ottobre 2021): 104471. http://dx.doi.org/10.1016/j.beproc.2021.104471.

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Ayanlade, Ayansina, Nathaniel Olugbade Adeoye e Oyekanmi Babatimehin. "Intra-annual climate variability and malaria transmission in Nigeria". Bulletin of Geography. Socio-economic Series 21, n. 21 (1 settembre 2013): 7–19. http://dx.doi.org/10.2478/bog-2013-0016.

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Abstract This study develops an integrated innovation for malaria early warning systems (MEWS), based on vulnerability monitoring, seasonal climate variability data, and epidemiologic surveillance. The main aim of the study is to examine the relationship between intra-annual climate variability and malaria transmission in Nigeria. For this study, climatic conditions considered suitable for the development of the malaria parasite and its transmission through the mosquito stage of its life cycle are temperatures within the range from 18°C to 32°C. Below 18°C the parasite development decreases significantly, while above 32°C the survival of the mosquito is compromised. Relative humidity greater than 60% is also considered a requirement for the mosquito to survive long enough for the parasite to develop sufficiently to be transmitted to its human host stage. The research findings show that seasonality of climate greatly influences the seasonality of malaria transmission. Specifically, rainfall plays an important role in the distribution and maintenance of breeding sites for the mosquito vector. Rainfall and surface water is required for the egg laying and larval stages of the mosquito life cycle and monthly rainfall above 80 mm is considered a requirement. Also, it is temperature that regulates the development rate of both the mosquito larvae and the malaria parasite (Plasmodium species) within the mosquito host. Relative humidity and temperature play an important role in the survival and longevity of the mosquito vector. This study is in conformity with the findings of the IPCC (2001) that malaria is caused by four distinct species of the Plasmodium parasite, transmitted by mosquitoes of the genus Anopheles, which are most abundant in tropical/subtropical regions, although they are also found in limited numbers in temperate climates.

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Katsiani, Asimina, Varvara Maliogka, Nikolaos Katis, Laurence Svanella-Dumas, Antonio Olmos, Ana Ruiz-García, Armelle Marais et al. "High-Throughput Sequencing Reveals Further Diversity of Little Cherry Virus 1 with Implications for Diagnostics". Viruses 10, n. 7 (21 luglio 2018): 385. http://dx.doi.org/10.3390/v10070385.

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Little cherry virus 1 (LChV1, Velarivirus, Closteroviridae) is a widespread pathogen of sweet or sour cherry and other Prunus species, which exhibits high genetic diversity and lacks a putative efficient transmission vector. Thus far, four distinct phylogenetic clusters of LChV1 have been described, including isolates from different Prunus species. The recent application of high throughput sequencing (HTS) technologies in fruit tree virology has facilitated the acquisition of new viral genomes and the study of virus diversity. In the present work, several new LChV1 isolates from different countries were fully sequenced using different HTS approaches. Our results reveal the presence of further genetic diversity within the LChV1 species. Interestingly, mixed infections of the same sweet cherry tree with different LChV1 variants were identified for the first time. Taken together, the high intra-host and intra-species diversities of LChV1 might affect its pathogenicity and have clear implications for its accurate diagnostics.

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Stack, J. Conrad, Pablo R. Murcia, Bryan T. Grenfell, James L. N. Wood e Edward C. Holmes. "Inferring the inter-host transmission of influenza A virus using patterns of intra-host genetic variation". Proceedings of the Royal Society B: Biological Sciences 280, n. 1750 (7 gennaio 2013): 20122173. http://dx.doi.org/10.1098/rspb.2012.2173.

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Influenza A viruses (IAVs) cause acute, highly transmissible infections in a wide range of animal species. Understanding how these viruses are transmitted within and between susceptible host populations is critical to the development of effective control strategies. While viral gene sequences have been used to make inferences about IAV transmission dynamics at the epidemiological scale, their utility in accurately determining patterns of inter-host transmission in the short-term—i.e. who infected whom—has not been strongly established. Herein, we use intra-host sequence data from the viral HA1 (hemagglutinin) gene domain from two transmission studies employing different IAV subtypes in their natural hosts—H3N8 in horses and H1N1 in pigs—to determine how well these data recapitulate the known pattern of inter-host transmission. Although no mutations were fixed over the course of either experimental transmission chain, we show that some minor, transient alleles can provide evidence of host-to-host transmission and, importantly, can be distinguished from those that cannot.

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RENWICK, A. R., P. C. L. WHITE e R. G. BENGIS. "Bovine tuberculosis in southern African wildlife: a multi-species host–pathogen system". Epidemiology and Infection 135, n. 4 (7 settembre 2006): 529–40. http://dx.doi.org/10.1017/s0950268806007205.

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SUMMARYThis review examines the current situation of bovine tuberculosis (bTB) in southern African savannah systems, and uses theory on multi-species host–pathogen systems to suggest possible options for future research and management. In southern Africa, the buffalo (Syncerus caffer) and the Kafue lechwe [Marsh antelope] (Kobus leche) have been found to be maintenance hosts for this disease, but the importance of other host species is becoming apparent. The role of other host species in the maintenance and spread of the disease varies, depending on the spatial distribution and resource utilization patterns of the species, disease susceptibility, transmission modes and the ecology of both host(s) and vector(s). Future research needs to identify the pathogenicity of bTB in each of the host species, and the mechanisms and rates of inter- and intra-specific transmission among different species, in order to develop multi-host models to understand the development and spread of the disease.

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Bonfante, Francesco, Livia Victoria Patrono, Roberta Aiello, Maria Serena Beato, Calogero Terregino e Ilaria Capua. "Susceptibility and intra-species transmission of the H9N2 G1 prototype lineage virus in Japanese quail and turkeys". Veterinary Microbiology 165, n. 1-2 (luglio 2013): 177–83. http://dx.doi.org/10.1016/j.vetmic.2013.03.014.

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Ledeneva, M. L., A. S. Vodopianov, G. A. Tkachenko, S. O. Vodopianov, S. S. Savchenko e I. M. Shpak. "DETECTION OF INDEL-MARKERS IN GENOMES OF BURKHOLDERIA PSEUDOMALLEI STRAINS FOR INTRA-SPECIES GENOTYPING". Journal of microbiology epidemiology immunobiology, n. 4 (28 agosto 2017): 35–41. http://dx.doi.org/10.36233/0372-9311-2017-4-35-41.

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Aim. Search for potential INDEL-markers in genomes of Burkholderia pseudomallei strains, as well as evaluation of the possibility of their use for intra-species genotyping. Materials and methods. Full-genome sequences of 25 В. pseudomallei strains with known geographic regions of isolation from GenBank database were studied. INDEL-marker search was carried out using authors’ program Gene Expert. Cluster analysis was carried out using genetic distance by R. Sokal and C. Michener and neighbor joining method. Results. 11 INDEL-markers were detected that allowed to split the studied strains into 13 genotypes. Spectrum of INDEL-patterns characteristic for Australian strains was determined. A possibility of existence of certain phylogeographic patterns of Thailand isolates is shown. Conclusion. A possibility of INDEL-markers to differentiate isolates of B. pseudomallei into 2 geographic populations (Australian and South-eastern Asia origin) that allows to determine the source of melioidosis outbreak and transmission routes of the pathogen is detected.

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SMITH, L. A., G. MARION, D. L. SWAIN, P. C. L. WHITE e M. R. HUTCHINGS. "Inter- and intra-specific exposure to parasites and pathogens via the faecal–oral route: a consequence of behaviour in a patchy environment". Epidemiology and Infection 137, n. 5 (24 settembre 2008): 630–43. http://dx.doi.org/10.1017/s0950268808001313.

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SUMMARYLivestock herbivores are at risk of inter- and intra-specific exposure to parasites/pathogens via the faecal–oral route during grazing. Each contact between livestock and faeces in the environment is a potential parasite/pathogen transmission event. Cattle grazing contact with faeces varies in relation to the species depositing the faeces and the distribution of the faeces. We used a foraging model to simulate the grazing behaviour of beef cattle in two grazing systems to compare the relative inter-specific and intra-specific exposure risks to parasites/pathogens. Overall, there is a greater level of intra-vs. inter-specific risk via the faecal–oral route. However, under certain conditions, particularly for microparasite infections, e.g. paratuberculosis in rabbits and bovine tuberculosis in badgers, wildlife may pose a significant exposure risk to parasites/pathogens. These risks can be enhanced when cattle are first turned out onto pasture and in situations where intra-specific variations in wildlife behaviour result in more dispersed defecation patterns.

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Gzyl, Anna, Ewa Augustynowicz, Ewa Mosiej, Monika Zawadka, Grzegorz Gniadek, Aneta Nowaczek e Janusz Slusarczyk. "Amplified fragment length polymorphism (AFLP) versus randomly amplified polymorphic DNA (RAPD) as new tools for inter- and intra-species differentiation within Bordetella". Journal of Medical Microbiology 54, n. 4 (1 aprile 2005): 333–46. http://dx.doi.org/10.1099/jmm.0.45690-0.

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Automated amplified fragment length polymorphism (AFLP) and randomly amplified polymorphic DNA (RAPD) techniques with fluorescently labelled primers were used to track differences among isolates of the eight known species of the Bordetella genus. Eighty-one representative strains of these species from international and Polish bacterial collections were genotyped according to RAPD protocols using primer 1254 or 1247, and AFLP involving EcoRI/MseI or newly designed SpeI/ApaI restriction/ligation/amplification procedures. By comparing AFLP and RAPD data, it was concluded that the discriminatory power of AFLP is higher in comparison with RAPD for both intra- and inter-species differentiation of isolates of the Bordetella genus. The most precise level of inter-species discrimination and the highest level of intra-species discrimination of the Bordetella isolates of the eight species were observed in the AFLP EcoRI/MseI and SpeI/ApaI sets, respectively. Both techniques might provide alternative tools for the identification of Bordetella at the genomic species and strain levels, and thus may be valuable in human and veterinary diagnostics as well as in epidemiology. By applying the AFLP technique presented in this article, more precise data on the emergence of newly acquired and/or on expanded clones and transmission routes of isolates of the Bordetella genus in the human and animal environments might be obtained.

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Hlokwe, T. M., P. van Helden e A. L. Michel. "Evidence of increasing intra and inter-species transmission of Mycobacterium bovis in South Africa: Are we losing the battle?" Preventive Veterinary Medicine 115, n. 1-2 (luglio 2014): 10–17. http://dx.doi.org/10.1016/j.prevetmed.2014.03.011.

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Mayer, L. W. "Use of plasmid profiles in epidemiologic surveillance of disease outbreaks and in tracing the transmission of antibiotic resistance." Clinical Microbiology Reviews 1, n. 2 (aprile 1988): 228–43. http://dx.doi.org/10.1128/cmr.1.2.228.

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Plasmids are circular deoxyribonucleic acid molecules that exist in bacteria, usually independent of the chromosome. The study of plasmids is important to medical microbiology because plasmids can encode genes for antibiotic resistance or virulence factors. Plasmids can also serve as markers of various bacterial strains when a typing system referred to as plasmid profiling, or plasmid fingerprinting is used. In these methods partially purified plasma deoxyribonucleic acid species are separated according to molecular size by agarose gel electrophoresis. In a second procedure, plasmid deoxyribonucleic acid which has been cleaved by restriction endonucleases can be separated by agarose gel electrophoresis and the resulting pattern of fragments can be used to verify the identity of bacterial isolates. Because many species of bacteria contain plasmids, plasmid profile typing has been used to investigate outbreaks of many bacterial diseases and to trace inter- and intra-species spread of antibiotic resistance.

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Lequime, Sebastian, Jean-Sébastien Dehecq, Séverine Matheus, Franck de Laval, Lionel Almeras, Sébastien Briolant e Albin Fontaine. "Modeling intra-mosquito dynamics of Zika virus and its dose-dependence confirms the low epidemic potential of Aedes albopictus". PLOS Pathogens 16, n. 12 (31 dicembre 2020): e1009068. http://dx.doi.org/10.1371/journal.ppat.1009068.

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Originating from African forests, Zika virus (ZIKV) has now emerged worldwide in urbanized areas, mainly transmitted by Aedes aegypti mosquitoes. Although Aedes albopictus can transmit ZIKV experimentally and was suspected to be a ZIKV vector in Central Africa, the potential of this species to sustain virus transmission was yet to be uncovered until the end of 2019, when several autochthonous transmissions of the virus vectored by Ae. albopictus occurred in France. Aside from these few locally acquired ZIKV infections, most territories colonized by Ae. albopictus have been spared so far. The risk level of ZIKV emergence in these areas remains however an open question. To assess Ae. albopictus’ vector potential for ZIKV and identify key virus outbreak predictors, we built a complete framework using the complementary combination of (i) dose-dependent experimental Ae. albopictus exposure to ZIKV followed by time-dependent assessment of infection and systemic infection rates, (ii) modeling of intra-human ZIKV viremia dynamics, and (iii) in silico epidemiological simulations using an Agent-Based Model. The highest risk of transmission occurred during the pre-symptomatic stage of the disease, at the peak of viremia. At this dose, mosquito infection probability was estimated to be 20%, and 21 days were required to reach the median systemic infection rates. Mosquito population origin, either temperate or tropical, had no impact on infection rates or intra-host virus dynamic. Despite these unfavorable characteristics for transmission, Ae. albopictus was still able to trigger and yield large outbreaks in a simulated environment in the presence of sufficiently high mosquito biting rates. Our results reveal a low but existing epidemic potential of Ae. albopictus for ZIKV, that might explain the absence of large scale ZIKV epidemics so far in territories occupied only by Ae. albopictus. They nevertheless support active surveillance and eradication programs in these territories to maintain the risk of emergence to a low level.

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Deheyn, Dimitri D., e Nerida G. Wilson. "Bioluminescent signals spatially amplified by wavelength-specific diffusion through the shell of a marine snail". Proceedings of the Royal Society B: Biological Sciences 278, n. 1715 (15 dicembre 2010): 2112–21. http://dx.doi.org/10.1098/rspb.2010.2203.

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Some living organisms produce visible light (bioluminescence) for intra- or interspecific visual communication. Here, we describe a remarkable bioluminescent adaptation in the marine snail Hinea brasiliana . This species produces a luminous display in response to mechanical stimulation caused by encounters with other motile organisms. The light is produced from discrete areas on the snail's body beneath the snail's shell, and must thus overcome this structural barrier to be viewed by an external receiver. The diffusion and transmission efficiency of the shell is greater than a commercial diffuser reference material. Most strikingly, the shell, although opaque and pigmented, selectively diffuses the blue-green wavelength of the species bioluminescence. This diffusion generates a luminous display that is enlarged relative to the original light source. This unusual shell thus allows spatially amplified outward transmission of light communication signals from the snail, while allowing the animal to remain safely inside its hard protective shell.

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Pattanawong, Urassaya, Chaturong Putaporntip, Azumi Kakino, Naoko Yoshida, Seiki Kobayashi, Surasuk Yanmanee, Somchai Jongwutiwes e Hiroshi Tachibana. "Analysis of D-A locus of tRNA-linked short tandem repeats reveals transmission of Entamoeba histolytica and E. dispar among students in the Thai-Myanmar border region of northwest Thailand". PLOS Neglected Tropical Diseases 15, n. 2 (18 febbraio 2021): e0009188. http://dx.doi.org/10.1371/journal.pntd.0009188.

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Intestinal parasitic infections, including those caused by Entamoeba species, are a persistent problem in rural areas of Thailand. The aims of this study were to identify pathogenic Entamoeba species and to analyze their genotypic diversity. Stool samples were collected from 1,233 students of three schools located in the Thai-Myanmar border region of Tak Province, Thailand. The prevalence of Entamoeba infection was measured by polymerase chain reaction (PCR) using species-specific primers. Thirty-one (2.5%) positive cases were detected for E. histolytica, 55 (4.5%) for E. dispar, and 271 (22.0%) for E. coli. Positive samples for E. histolytica and E. dispar were exclusively obtained from a few school classes, whereas E. coli was detected in all grades. No infections caused by E. moshkovskii, E. nuttalli, E. chattoni, and E. polecki were detected in the students studied. The D-A locus of tRNA-linked short tandem repeats was analyzed in samples of E. histolytica (n = 13) and E. dispar (n = 47) to investigate their diversity and potential modes of transmission. Five genotypes of E. histolytica and 13 genotypes of E. dispar were identified. Sequences of the D-A were divergent, but several unique genotypes were significantly prevalent in limited classes, indicating that intra-classroom transmission has occurred. As it was unlikely that infection would have been limited within school classes if the mode of transmission of E. histolytica and E. dispar had been through the intake of contaminated drinking water or food, these results suggest a direct or indirect person-to-person transmission mode within school classes. Positive rates for three Entamoeba species were 2-fold higher in students who had siblings in the schools than in those without siblings, suggesting that transmission occurred even at home due to heavy contacts among siblings.

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de Araújo, Walter Santos, Thallyta Maria Vieira, Guilherme Antunes de Souza, Isaque Clementino Bezerra, Paulo Henrique Costa Corgosinho e Magno Augusto Zazá Borges. "Nocturnal Mosquitoes of Pará State in the Brazilian Amazon: Species Composition, Habitat Segregation, and Seasonal Variation". Journal of Medical Entomology 57, n. 6 (2 giugno 2020): 1913–19. http://dx.doi.org/10.1093/jme/tjaa103.

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Abstract Mosquitoes (Diptera: Culicidae) are one of the most important disease vector species in the world. Many species have a high degree of anthropophilia and are often found in human habitations. In the present study, we have inventoried the nocturnal mosquito assemblage in intra-, peri-, and extradomicile environments in four municipalities in Pará, Brazil. At each municipality, a residence was selected and the mosquitoes were sampled using the protected human attraction capture and Shannon trap methods in April (rainy season) and August 2018 (dry season). We have collected a total of 696 mosquito specimens belonging to 8 genera and 17 species. The most abundant species were Mansonia (Mansonoides) titillans (Walker) (366/696, 52.6%), Anopheles (Nyssorhynchus) albitarsis Lynch-Arribálzaga (97/696, 13.9%), and Culex (Culex) quinquefasciatus Say (93/696, 13.4%). Mosquito richness, abundance, and composition did not differ between intra-, peri-, and extradomicile environments suggesting limited habitat segregation among the different species. However, mosquito species richness and mosquito species abundance were significantly higher during the rainy season than during the dry season, suggesting increased mosquito activity during the rainy season. We detected several important vector species of human diseases including Aedes (Stegomyia) aegypti (Linnaeus), Anopheles (Nyssorhynchus) darlingi Root, Haemagogus (Conopostegus) leucocelaenus (Dyar and Shannon), Coquillettidia (Coquillettidia) venezuelensis (Theobald), and Culex (Culex) quinquefasciatus which are the main transmitters of dengue, malaria, yellow fever, mayaro, and oropouche fever, respectively. As inventories of disease-carrying mosquitoes in the region are very scarce, mainly in residential environments, our results suggest high potential for mosquito-borne disease transmission in Pará State.

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EPIS, S., D. SASSERA, T. BENINATI, N. LO, L. BEATI, J. PIESMAN, L. RINALDI et al. "Midichloria mitochondriiis widespread in hard ticks (Ixodidae) and resides in the mitochondria of phylogenetically diverse species". Parasitology 135, n. 4 (21 gennaio 2008): 485–94. http://dx.doi.org/10.1017/s0031182007004052.

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SUMMARYThe hard tickIxodes ricinus(Ixodidae) is the sole animal thus far shown to harbour an intra-mitochondrial bacterium, which has recently been namedMidichloria mitochondrii. The objectives of this work were (i) to screen ixodid ticks forMidichloria-related bacteria and (ii) to determine whether these bacteria exploit the intra-mitochondrial niche in other tick species. Our main goal was to discover further models of this peculiar form of symbiosis. We have thus performed a PCR screening forMidichloria-related bacteria in samples of ixodid ticks collected in Italy, North America and Iceland. A total of 7 newly examined species from 5 genera were found positive for bacteria closely related toM. mitochondrii. Samples of the tick speciesRhipicephalus bursa, found positive in the PCR screening, were analysed with transmission electron microscopy, which revealed the presence of bacteria both in the cytoplasm and in the mitochondria of the oocytes. There is thus evidence that bacteria invade mitochondria in at least 2 tick species. Phylogenetic analysis on the bacterial 16S rRNA gene sequences generated from positive specimens revealed that the bacteria form a monophyletic group within the order Rickettsiales. The phylogeny ofMidichloriasymbionts and related bacteria does not appear completely congruent with the phylogeny of the hosts.

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Sabeta, Claude T., Denise A. Marston, Lorraine M. McElhinney, Daniel L. Horton, Baby M. N. Phahladira e Anthony R. Fooks. "Rabies in the African Civet: An Incidental Host for Lyssaviruses?" Viruses 12, n. 4 (27 marzo 2020): 368. http://dx.doi.org/10.3390/v12040368.

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In South Africa, canid rabies virus (RABV) infection is maintained in domestic and wildlife species. The identification of rabies in African civets raised the question of whether this wildlife carnivore is a potential reservoir host of RABVs of direct and ancestral dog origin (dog-maintained and dog-derived origins) with an independent cycle of transmission. Genetic analyses of African civet nucleoprotein sequences for 23 African civet RABVs and historically published sequences demonstrated that RABVs from African civets have two origins related to dog and mongoose rabies enzootics. The data support observations of the interaction of civets with domestic dogs and wildlife mongooses, mostly in Northern South Africa and North-East Zimbabwe. Within each host species clade, African civet RABVs group exclusively together, implying intra-species virus transfer occurs readily. The canid RABV clade appears to support virus transfer more readily between hosts than mongoose RABVs. Furthermore, these data probably indicate short transmission chains with conspecifics that may be related to transient rabies maintenance in African civets. Hence, it is important to continue monitoring the emergence of lyssaviruses in this host. Observations from this study are supported by ongoing and independent similar cases, in which bat-eared foxes and black-backed jackal species maintain independent rabies cycles of what were once dog-maintained RABVs.

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Geoghegan, Jemma L., Alistair M. Senior e Edward C. Holmes. "Pathogen population bottlenecks and adaptive landscapes: overcoming the barriers to disease emergence". Proceedings of the Royal Society B: Biological Sciences 283, n. 1837 (31 agosto 2016): 20160727. http://dx.doi.org/10.1098/rspb.2016.0727.

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Emerging diseases are a major challenge to public health. Revealing the evolutionary processes that allow novel pathogens to adapt to new hosts, also the potential barriers to host adaptation, is central to understanding the drivers of disease emergence. In particular, it is unclear how the genetics and ecology of pathogens interact to shape the likelihood of successful cross-species transmission. To better understand the determinants of host adaptation and emergence, we modelled key aspects of pathogen evolutionary dynamics at both intra- and inter-host scales, using parameter values similar to those observed in influenza virus. We considered the possibility of acquiring the necessary host adaptive mutations both before (‘off-the-shelf’ emergence) and after (‘tailor-made’ emergence) a virus is transmitted from a donor to a new recipient species. Under both scenarios, population bottlenecks at inter-host transmission act as a major barrier to host adaptation, greatly limiting the number of adaptive mutations that are able to cross the species barrier. In addition, virus emergence is hindered if the fitness valley between the donor and recipient hosts is either too steep or too shallow. Overall, our results reveal where in evolutionary parameter space a virus could adapt to and become transmissible in a new species.

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Wentzel, Jeanette, Cory Gall, Mark Bourn, Juan De Beer, Ferreira du Plessis e Geoffrey T. Fosgate. "Carnivore Detection at the Domestic/Wildlife Interface within Mpumalanga Province, South Africa". Animals 11, n. 9 (29 agosto 2021): 2535. http://dx.doi.org/10.3390/ani11092535.

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South African protected areas account for 8% of the total landmass according to World Bank indicators. Effective conservation of biodiversity in protected areas requires the development of specific reserve management objectives addressing species and disease management. The primary objective of the current study was to identify predictors of carnivore detection in an effort to inform carnivore species management plans on Andover and Manyeleti nature reserves in South Africa. A limited number of camera traps were placed randomly using a grid system. Species detection data were analysed using mixed-effects logistic regression and Spearman’s correlation coefficients. Deterministic inverse distance weighted distribution maps were used to describe the spatial distribution of carnivore species. Camera traps identified similar species as traditional call-up surveys during the study and would be useful as an adjunct census method. Carnivore detection was associated with several variables, including the presence of specific prey species. The measured intra-and interspecies interactions suggested the risk of disease transmission among species, and vaccination for prevalent diseases should be considered to manage this risk.

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Ogawa, Saki, Tomoaki Murakami, Yasuo Inoshima e Naotaka Ishiguro. "Effect of heating on the stability of amyloid A (AA) fibrils and the intra- and cross-species transmission of AA amyloidosis". Amyloid 22, n. 4 (2 ottobre 2015): 236–43. http://dx.doi.org/10.3109/13506129.2015.1095735.

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Yang, Qian, Xuan Dong, Guosi Xie, Songzhe Fu, Peizhuo Zou, Jing Sun, Yi Wang e Jie Huang. "Comparative genomic analysis unravels the transmission pattern and intra-species divergence of acute hepatopancreatic necrosis disease (AHPND)-causing Vibrio parahaemolyticus strains". Molecular Genetics and Genomics 294, n. 4 (9 aprile 2019): 1007–22. http://dx.doi.org/10.1007/s00438-019-01559-7.

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Jenkins, Stephen N., Emmanuel Okello, Paul V. Rossitto, Terry W. Lehenbauer, John Champagne, Maria C. T. Penedo, Andréia G. Arruda et al. "Molecular epidemiology of coagulase-negativeStaphylococcusspecies isolated at different lactation stages from dairy cattle in the United States". PeerJ 7 (6 maggio 2019): e6749. http://dx.doi.org/10.7717/peerj.6749.

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BackgroundCoagulase negativeStaphylococcus(CNS) species are currently the most prevalent intra-mammary pathogens causing subclinical mastitis and occasional clinical mastitis or persistent infection in lactating dairy cattle. More than 10 CNS species have been identified, but they are generally managed as one group on most dairies in the United States. However, improved management decisions and treatment outcomes may be achieved with better understanding of the prevalent species, pathogenicity and strain diversity within and across dairies.MethodologyA total of 604 CNS isolates were cultured from milk samples collected during a dry-cow treatment clinical trial conducted on 6 dairy herds in 4 states in the US. All the study cows were randomized to receive 1 of the 3 different intra-mammary antimicrobial infusions (Quatermaster, Spectramast DC or ToMorrow Dry Cow) at dry-off. Milk samples were collected at dry-off, calving (0–6 days in milk, DIM), post-calving (7–13 DIM) and at mastitis events within the first 100 DIM. The CNS isolates were identified to species level by partial sequencing of therpoβgene, and genetic relatedness within species was investigated by phylogenetic analysis of the pulse-field gel electrophoresis profiles of the isolates.ResultsThe major CNS species identified wereS. chromogenes(48.3%),S. haemolyticus(17.9%),S. simulansandS. epidermidis(each at 6.5%). Other CNS species identified at lower frequencies includedS. hominis,S. auricularis,S. sciuri,S. sppKS-SP,S. capitis,S. cohnii,S. warneri,S. pasteuri, S. xylosus, S. hyicus, S. equorum, S. microti, S. rostri, S. gallinarum, S. saprophyticusandS. succinus. Phylogenetic analyses of the major species types demonstrated an association between genetic relatedness and epidemiological distributions ofS. chromogenes, S. simulans, S. haemolyticusandS. auricularis.Additionally, identical strains ofS. chromogenesandS. simulanswere isolated from the same udder quarter of several cows at consecutive sample stages. The rest of the minor species had no deducible genetic-epidemiological link.DiscussionThe observed association between genetic and epidemiological distributions indicated animal-adapted nature of four CNS species, suggesting possible host-adapted and environmental transmission of these species. Multi-stage isolation of the same udder quarter strain was evidence for chronic intra-mammary infection.ConclusionThe different CNS species and strains circulating on US dairy herds were genetically diverse. Four species identified were likely udder-adapted pathogens, 2 of which caused persistent infection. Our findings are important in guiding the design of effective mastitis control strategies.

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D’Agata, Erika M. C., Daniel Habtemariam e Susan Mitchell. "Multidrug-Resistant Gram-Negative Bacteria: Inter- and Intradissemination Among Nursing Homes of Residents With Advanced Dementia". Infection Control & Hospital Epidemiology 36, n. 8 (29 aprile 2015): 930–35. http://dx.doi.org/10.1017/ice.2015.97.

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OBJECTIVETo quantify the extent of inter– and intra–nursing home transmission of multidrug-resistant gram-negative bacteria (MDRGN) among residents with advanced dementia and characterize MDRGN colonization among these residents.DESIGNProspective cohort study.SETTINGTwenty-two nursing homes in the greater Boston, Massachusetts, area.PATIENTSResidents with advanced dementia.METHODSSerial rectal surveillance cultures for MDRGN and resident characteristics were obtained every 3 months for 12 months or until death. Molecular typing of MDRGN isolates was performed by pulsed-field gel electrophoresis.RESULTSA total of 190 MDRGN isolates from 152 residents with advanced dementia were included in the analyses. Both intra– and inter–nursing home transmission were identified. Genetically related MDRGN strains, recovered from different residents, were detected in 18 (82%) of the 22 nursing homes. The percent of clonally related strains in these nursing homes ranged from 0% to 86% (average, 35%). More than 50% of strains were clonally related in 3 nursing homes. Co-colonization with more than 1 different MDRGN species occurred among 28 residents (18.4%). A total of 168 (88.4%), 20 (10.5%), and 2 (1.0%) of MDRGN isolates were resistant to 3, 4, and 5 different antimicrobials or antimicrobial classes, respectively.CONCLUSIONSMDRGN are spread both within and between nursing homes among residents with advanced dementia. Infection control interventions should begin to target this high-risk group of nursing home residents.Infect Control Hosp Epidemiol2015;36(8):930–935

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Trzmiel, Katarzyna, Wiktoria Szydło e Beata Hasiów-Jaroszewska. "Biological and molecular characterisation of the two Polish Wheat streak mosaic virus isolates and their transmission by wheat curl mites". Plant Protection Science 57, No. 3 (10 giugno 2021): 171–78. http://dx.doi.org/10.17221/104/2020-pps.

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Wheat streak mosaic virus (WSMV) is a serious and widespread pathogen in the wheat-producing areas in the USA while, in Europe, it has been considered a minor threat to cereal crops. In the past, WSMV was detected in wheat, triticale and maize plants in Poland by DAS-ELISA. Here, we present the biological and molecular characterisation of WSMV-Sze and WSMV-Sosn isolates collected from western and southern Poland and report their transmissibility by the widespread wheat curl mite (WCM) lineage MT-8. The performed bioassays revealed that the analysed WSMV isolates infect wheat, barley, triticale, rye, oat and maize, but they differ in the symptoms induced on the infected plants. Moreover, they infect Bromus hordeaceus Linnaeus, which is increasingly recognised as a virus reservoir. The full-length genome sequence of both isolates was obtained and compared with the others described to date. The phylogenetic analysis revealed that the Polish isolates are clustered with the earlier described type B isolates of WSMV from Europe and Iran. The recombination analysis revealed the presence of recombinant variants in WSMV population and indicated that the WSMV-Sosn might originated from the intra-species recombination of the WSMV-Sze and WSMV-Cz isolates.

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Matsuura, E. T., S. I. Chigusa e Y. Niki. "Induction of mitochondrial DNA heteroplasmy by intra- and interspecific transplantation of germ plasm in Drosophila." Genetics 122, n. 3 (1 luglio 1989): 663–67. http://dx.doi.org/10.1093/genetics/122.3.663.

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Abstract A new experimental system for inducing mitochondrial DNA heteroplasmy in Drosophila was developed. By transplanting the germ plasm of Drosophila melanogaster and Drosophila mauritiana into the posterior pole of the recipient eggs of D. melanogaster, it was possible to introduce foreign mitochondria into the recipient female germline. Heteroplasmic individuals containing both donor and recipient mtDNA were obtained in intra- and interspecific combinations at similar frequencies. The proportion of donor-derived mtDNA in the heteroplasmic individuals varied considerably from individual to individual irrespective of the donor species used. No significant decrease in or elimination of donor mtDNA was observed, and the heteroplasmic state in female germlines persisted for several generations. The present system should serve very much to promote the study and clarification of the transmission genetics of mtDNA in insects.

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Cornec, C., Y. Hingrat, T. Aubin e F. Rybak. "Booming far: the long-range vocal strategy of a lekking bird". Royal Society Open Science 4, n. 8 (agosto 2017): 170594. http://dx.doi.org/10.1098/rsos.170594.

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The pressures of selection acting on transmission of information by acoustic signals are particularly high in long-distance communication networks. Males of the North African houbara bustard ( Chlamydotis undulata undulata ) produce extremely low-frequency vocalizations called ‘booms’ as a component of their courtship displays. These displays are performed on sites separated by a distance of on average 550 m, constituting exploded leks. Here, we investigate the acoustic features of booms involved in species-specific identity. We first assessed the modifications of acoustic parameters during boom transmission at long range within the natural habitat of the species, finding that the frequency content of booms was reliably transmitted up to 600 m. Additionally, by testing males' behavioural responses to playbacks of modified signals, we found that the presence of the second harmonic and the frequency modulation are the key parameters for species identification, and also that a sequence of booms elicited stronger responses than a single boom. Thus, the coding–decoding process relies on redundant and propagation-resistant features, making the booms particularly well adapted for the long-range transmission of information between males. Moreover, by experimentally disentangling the presentation of visual and acoustic signals, we showed that during the booming phase of courtship, the two sensory modalities act in synergy. The acoustic component is dominant in the context of intra-sexual competition. While the visual component is not necessary to induce agonistic response, it acts as an amplifier and reduces the time of detection of the signaller. The utilization of these adaptive strategies allows houbara males to maximize the active space of vocalizations emitted in exploded leks.

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LEE, NAM-JU, YOSEPH SEO, JANG-SEU KI e OK-MIN LEE. "Morphology and molecular description of Wilmottia koreana sp. nov. (Oscillatoriales, Cyanobacteria) isolated from the Republic of Korea". Phytotaxa 447, n. 4 (11 giugno 2020): 237–51. http://dx.doi.org/10.11646/phytotaxa.447.4.2.

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Two types of Wilmottia (Cyanobacteria) were collected from the tree-bark of a tree on Mt. Gwanggyo in Suwon City, Gyeonggi-do and a rock wall of Haje Port, Geum River in Jeollabuk-do, Republic of Korea. Morphological observations using light microscopy (LM) and transmission electron microscopy (TEM) revealed that one species was Wilmottia murrayi (Coleofasciculaceae, Oscillatoriales) and the other had similar morphology to W. murrayi, with considerable genetic variations, and thus, it was described as a new species named Wilmottia koreana. Phylogenetic analyses of the 16S rRNA revealed that the family Coleofasciculaceae was clearly separated into taxonomic groups of each genus, and in them, Wilmottia forms a monophyletic lineage. W. koreana diverged the earliest, forming a unique clade separate from the others. Statistical analyses showed that the inter-species genetic distances of Wilmottia were significantly different from the intra-species distances (t-test, P < 0.001). Additionally, the secondary structures of D1–D1’, Box-B, and the V3 helices were different among the Wilmottia species. These results demonstrated that the proposed new Wilmottia species was unique in molecular traits. Therefore, we propose this to be a new species belonging to the genus Wilmottia with the name Wilmottia koreana sp. nov.

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Weese, J. Scott. "Clostridium (Clostridioides) difficile in animals". Journal of Veterinary Diagnostic Investigation 32, n. 2 (6 gennaio 2020): 213–21. http://dx.doi.org/10.1177/1040638719899081.

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Clostridium ( Clostridioides) difficile is a gram-positive, spore-forming bacterium that is an important cause of disease in people, a variably important cause of disease in some animal species, and an apparently harmless commensal in others. Regardless of whether it is a known pathogen in a particular species, it can also be found in healthy individuals, sometimes at high prevalences and typically with higher rates of carriage in young individuals. As it is investigated in more animal species, it is apparent that this bacterium is widely disseminated in a diverse range of domestic and wild animal species. Although it can be found in most species in which investigations have been performed, there are pronounced intra- and inter-species differences in prevalence and clinical relevance. A wide range of strains can be identified, some that appear to be animal associated and others that are found in humans and animals. A large percentage of strains that cause disease in people can at least sporadically be found in animals. It is a potentially important zoonotic pathogen, but there is limited direct evidence of animal–human transmission. Although C. difficile has been studied extensively over the past few decades, it remains an enigmatic organism in many ways.

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Maldonado, Manuel. "Intergenerational transmission of symbiotic bacteria in oviparous and viviparous demosponges, with emphasis on intracytoplasmically-compartmented bacterial types". Journal of the Marine Biological Association of the United Kingdom 87, n. 6 (dicembre 2007): 1701–13. http://dx.doi.org/10.1017/s0025315407058080.

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Recent molecular detection of vast microbial communities exclusively associated with sponges has made evident the need for a better understanding of the mechanisms by which these symbiotic microbes are handled and transferred from one sponge generation to another. This transmission electron microscopy (TEM) study investigated the occurrence of symbiotic bacteria in free-swimming larvae of two viviparous species (Haliclona caerulea and Corticium candelabrum) and spawned gametes of two oviparous species (Chondrilla nucula and Petrosia ficiformis). Complex microbial communities were found in these sponges, which in two cases included bacteria characterized by an intra-cytoplasmic membrane (ICM). When ICM-bearing and ICM-lacking bacteria co-existed, they were transferred following identical pathways. Nevertheless, the mechanism for microbial transference varied substantially between species. In C. nucula, a combination of intercellular symbiotic ICM-bearing and ICM-lacking bacteria, along with cyanobacteria and yeasts, were collected from the mesohyl by amoeboid nurse cells, then transported and transferred to the oocytes. In the case of Corticium candelabrum, intercellular bacteria did not enter the gametes, but spread into the division furrows of early embryos and proliferated in the central cavity of the free-swimming larva. Surprisingly, symbiotic bacteria were not vertically transmitted by P. ficiformis gametes or embryos, but apparently acquired from the environment by the juveniles of each new generation. This study failed to unravel the mechanism by which the intercellular endosymbiotic bacterium found in the central mesohyl of the H. caerulea larva got there. Nevertheless, the ultrastructure of this bacterial rod, which was characterized by a star-shaped cross section with nine radial protrusions, an ICM-bound riboplasm, and a putative membrane-bound acidocalcisome, suggested that it may represent a novel organization grade within the prokaryotes. It combines traits occurring in members of Poribacteria, Planctomycetes and Verrucomicrobia, emerging as one of the most complex prokaryotic architectures known to date.

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Al-Dwairi, Ziad Nawaf, Azmi Mohammad-Ghaleb Darwazeh e Abd Al-Wahab Al-Zwairi. "The Relationship between Tobacco Smoking and Oral Colonization with Candida Species". Journal of Contemporary Dental Practice 11, n. 3 (2010): 17–24. http://dx.doi.org/10.5005/jcdp-11-3-17.

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Abstract Aim The aim of this study was to assess and compare the quantitative and qualitative oral colonization of Candida species between a group of healthy tobacco smokers and a comparable group of nonsmokers, and to investigate a possible correlation between oral candidal colonization and the quantity or duration of the smoking habit. Methods and Materials Fifty smokers and 50 nonsmokers were included in the study. Candida species were isolated using the concentrated oral rinse (COR) technique and identified using the germ tube test and API 20 C AUX yeast identification system. Results Overall candidal transmission was 84 percent. Candida species were isolated from 42 (84 percent) of the smokers and 37 (74 percent) of the nonsmokers (p>0.05). The mean CFU/ml were 333 (SD=358) and 268 (SD=332), respectively (p>0.05). Conclusion Tobacco smoking did not appear to increase oral colonization with Candida species in healthy subjects. Clinical Significance The effects of smoking on oral tissues and the mechanisms by which Candida proliferate intra-orally as a result of cigarette smoking warrant additional study. Citation Darwazeh AM, Al-Dwairi ZN, Al-Zwairi AA. The Relationship between Tobacco Smoking and Oral Colonization with Candida Species. J Contemp Dent Pract [Internet]. 2010 May; 11(3):017-024. Available from: http://www.thejcdp. com/journal/view/volume11-issue3-al_dwairi

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LIU, RONGSONG, GERGELY RÖST e STEPHEN A. GOURLEY. "Age-dependent intra-specific competition in pre-adult life stages and its effects on adult population dynamics". European Journal of Applied Mathematics 27, n. 1 (12 agosto 2015): 131–56. http://dx.doi.org/10.1017/s0956792515000418.

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Intra-specific competition in insect and amphibian species is often experienced in completely different ways in their distinct life stages. Competition among larvae is important because it can impact on adult traits that affect disease transmission, yet mathematical models often ignore larval competition. We present two models of larval competition in the form of delay differential equations for the adult population derived from age-structured models that include larval competition. We present a simple prototype equation that models larval competition in a simplistic way. Recognising that individual larvae experience competition from other larvae at various stages of development, we then derive a more complex equation containing an integral with a kernel that quantifies the competitive effect of larvae of ageāon larvae of agea. In some parameter regimes, this model and the famous spruce budworm model have similar dynamics, with the possibility of multiple co-existing equilibria. Results on boundedness and persistence are also proved.

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Perry, S. F., G. G. Goss e P. Laurent. "The interrelationships between gill chloride cell morphology and ionic uptake in four freshwater teleosts". Canadian Journal of Zoology 70, n. 9 (1 settembre 1992): 1775–86. http://dx.doi.org/10.1139/z92-245.

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Abstract (sommario):

We have investigated the role of the gill chloride cell in transbranchial Na+ and Cl− uptake in four species of freshwater teleost maintained in water of identical ionic composition. The basic experimental protocol was to determine whether interspecific variability in the rates of whole body Na+ or Cl− uptake could be accounted for by similar interspecific variability in the fractional area of branchial chloride cells exposed to the external environment. To investigate the underlying cause(s) of intraspecific variability, chronic (10 day) treatment with cortisol in each species was used as a tool to evoke variations in both the rates of ionic uptake and chloride cell morphology. Examination of transmission and scanning electron micrographs revealed distinctive chloride cell and pavement cell morphology in each species. The results of quantitative morphometry, based on analysis of scanning electron micrographs, demonstrated that European eel (Anguilla anguilla) possessed the lowest chloride cell fractional area on the filament epithelium (11 288 ± 2133 μm2/mm2) followed, in increasing order, by brown bullhead catfish (Ictalurus nebulosus; 48 341 ± 7694 μm2/mm2), tilapia (Oreochromis mossambicus; 85 194 ± 10 326 μm2/mm2), and rainbow trout (Oncorhynchus mykiss; 146 333 ± 31 356 μm2/mm2). With the exception of rainbow trout, chronic treatment with cortisol caused significant increases in the chloride cell fractional area of filament epithelium owing to enlargement of the surface area of individual chloride cells and (or) proliferation of chloride cells. Both the inter- and intra-specific differences in chloride cell fractional area were reflected by similar differences in whole body Cl− and Na+ uptake. The results of correlation analysis revealed (with the exception of whole body Na+ uptake in A. anguilla) significant correlations between chloride cell fractional area and the rates of ionic uptake within and among the four species that were examined. These data suggest that the chloride cell is a significant site of ionic uptake in freshwater teleosts and that both inter- and intra-specific differences in the rates of ionic uptake can be explained by variability in the surface area of chloride cells on the gill epithelia.

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Silva, Maria Beatriz Araújo, Ana Virgínia Matos Sá Barreto, Helker Albuquerque da Silva, Cleber Galvão, Dayse Rocha, José Jurberg e Rodrigo Gurgel-Gonçalves. "Synanthropic triatomines (Hemiptera, Reduviidae) in the state of Pernambuco, Brazil: geographical distribution and natural Trypanosoma infection rates between 2006 and 2007". Revista da Sociedade Brasileira de Medicina Tropical 45, n. 1 (febbraio 2012): 60–65. http://dx.doi.org/10.1590/s0037-86822012000100012.

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INTRODUCTION: The present study shows a descriptive analysis of triatomine occurrence and its natural Trypanosoma infection rates in the state of Pernambuco, Brazil, between 2006 and 2007. METHODS: Entomological data for the species, such as specimens captured in both intra and peridomiciles and natural infection index, were obtained via domiciliary capture in 147 municipalities from 11 Regional Managements of Health. The database was obtained from a sample of insects (100% infected and 20% non-infected) sent to the Central Laboratory of Pernambuco. RESULTS: A total of 18,029 triatomines were analyzed from 138 municipalities of the state. Triatoma pseudomaculata (35%), Triatoma brasiliensis (34%), and Panstrongylus lutzi (25%) were the most captured species. These species also showed a widespread geographical distribution in the state. Panstrongylus megistus, Triatoma petrocchiae, Triatoma melanocephala, Triatoma sordida, Rhodnius nasutus, Rhodnius neglectus, and Triatoma infestans showed more limited geographical distribution and lower relative abundance. The parasitological research showed that 8.8% of the triatomines were naturally infected with flagellates morphologically similar to Trypanosoma cruzi and 91.3% of them were captured inside houses in 113 municipalities. P. lutzi showed the highest rates of natural infection. CONCLUSIONS: After the control of T. infestans, synanthropic species, such as T. brasiliensis, T. pseudomaculata, and P. lutzi, maintain the risk of T. cruzi transmission to humans in the state of Pernambuco. These species are widely distributed, and infected specimens have been found inside houses. Thus, an enhanced surveillance and vector control of Chagas disease is recommended in Pernambuco.

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Correa, M. C. G., T. Zaviezo, J. Le Maguet, E. Herrbach e T. Malausa. "Characterization of microsatellite DNA libraries from three mealybug species and development of microsatellite markers for Pseudococcus viburni (Hemiptera: Pseudococcidae)". Bulletin of Entomological Research 104, n. 2 (17 dicembre 2013): 213–20. http://dx.doi.org/10.1017/s0007485313000667.

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AbstractMealybugs (Hemiptera: Pseudococcidae) are important pests for crops worldwide. Different species, cryptic taxa under the same species name or even populations within a species can differ in biological characteristics, such as phenology, resistance to insecticides, virus transmission and susceptibility to natural enemies. Therefore, their management efficacy depends on their accurate identification. Microsatellite genetic markers are efficient in revealing the fine-scale taxonomic status of insects, both at inter- and intra-specific level. Despite their potential uses, microsatellites have been developed only for one mealybug species so far. Hence, it is unclear whether microsatellites may be useful to assess mealybug population differentiation and structuring. In this work, we tested the feasibility of developing microsatellite markers in mealybugs by: (i) producing and characterizing microsatellite DNA libraries for three species: Pseudococcus viburni, Pseudococcus comstocki and Heliococcus bohemicus, and (ii) by developing and testing markers for Ps. viburni. The obtained libraries contained balanced percentages of dinucleotide (ranging from 15 to 25%) and trinucleotide (from 5 to 17%) motifs. The marker setup for Ps. viburni was successful, although 70% of the primers initially tested were discarded for a lack of polymorphism. Finally, 25 markers were combined in two multiplex polymerase chain reactions with 21 displaying no evidence of deviation from Hardy–Weinberg equilibrium. Ps. viburni markers were tested on one population from France and one from Chile. The markers revealed a significant genetic differentiation between the two populations with an Fst estimate of 0.266.

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Messa, Augusto, Pamela C. Köster, Marcelino Garrine, Tacilta Nhampossa, Sérgio Massora, Anélsio Cossa, Quique Bassat et al. "Molecular Characterisation of Cryptosporidium spp. in Mozambican Children Younger than 5 Years Enrolled in a Matched Case-Control Study on the Aetiology of Diarrhoeal Disease". Pathogens 10, n. 4 (9 aprile 2021): 452. http://dx.doi.org/10.3390/pathogens10040452.

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Cryptosporidium is a leading cause of childhood diarrhoea and associated physical and cognitive impairment in low-resource settings. Cryptosporidium-positive faecal samples (n = 190) from children aged ≤ 5 years enrolled in the Global Enteric Multicenter Study (GEMS) in Mozambique detected by ELISA (11.5%, 430/3754) were successfully PCR-amplified and sequenced at the gp60 or ssu rRNA loci for species determination and genotyping. Three Cryptosporidium species including C. hominis (72.6%, 138/190), C. parvum (22.6%, 43/190), and C. meleagridis (4.2%, 8/190) were detected. Children ≤ 23 months were more exposed to Cryptosporidium spp. infections than older children. Both C. hominis and C. parvum were more prevalent among children with diarrhoeal disease compared to those children without it (47.6% vs. 33.3%, p = 0.007 and 23.7% vs. 11.8%, p = 0.014, respectively). A high intra-species genetic variability was observed within C. hominis (subtype families Ia, Ib, Id, Ie, and If) and C. parvum (subtype families IIb, IIc, IIe, and IIi) but not within C. meleagridis (subtype family IIIb). No association between Cryptosporidium species/genotypes and child’s age was demonstrated. The predominance of C. hominis and C. parvum IIc suggests that most of the Cryptosporidium infections were anthroponotically transmitted, although zoonotic transmission events also occurred at an unknown rate. The role of livestock, poultry, and other domestic animal species as sources of environmental contamination and human cryptosporidiosis should be investigated in further molecular epidemiological studies in Mozambique.

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Černi, Silvija, Katarina Hančević e Dijana Škorić. "Citruses in Croatia – cultivation, major virus and viroid threats and challenges". Acta botanica Croatica 79, n. 2 (13 luglio 2020): 228–35. http://dx.doi.org/10.37427/botcro-2020-027.

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Abstract (sommario):

Although Croatia is not often perceived as a citrus growing country, citrus species have been planted in the Croatian southern coastal part for centuries. Citrus had always been important as a source of vitamins and micronutrients for local consumption, but with the introduction of Satsuma mandarins (Citrus unshiu Marc.) citrus production started its commercial development. The Croatian coast is probably the northernmost commercial citrus growing area globally with several agroecological constraints influencing citrus production. However, Satsuma mandarins, the most cold-tolerant citrus of economic interest, are successfully cultivated resulting in an excellent quality of fruits that easily finds a market niche. Unfortunately, with the import of plant material in the last century, the simultaneous introduction of viral and subviral pathogens occurred. The most important are Citrus tristeza virus and Citrus exocortis viroid. As certain rootstock-scion combinations are tolerant to virus or viroid infections and display no obvious symptoms, these pathogens have been continuously spreading by plant propagation. Molecular and biological analyses revealed the existence of pathotypes not believed to be endemically present in the Mediterranean region. Their high intra-isolate genetic variability and frequent coinfections suggest that this geographical region presents a sort of a biological enclave of potentially threatening pathogens. Their transmission from this agroecological niche to areas where sensitive rootstock-scion combinations are common presents a serious risk to citrus production, especially when global warming and the resulting migration of efficient vector species are considered. Comprehensive pathogen monitoring is important for improving citrus production and the prevention of pathogen transmission.

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Townsend, Jr., Victor R., e Bruce E. Felgenhauer. "Variation in cuticular scales of the lynx spiders of the genus Hamataliwa and other genera (Araneae, Oxyopidae)". Canadian Journal of Zoology 77, n. 11 (1 dicembre 1999): 1705–16. http://dx.doi.org/10.1139/z99-139.

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This study presents the first complete description of the external and internal morphology of cuticular scales of spiders of the genus Hamataliwa and is also the first examination of intrageneric variation in the morphology of the scales of the lynx spiders (Oxyopidae). The cuticular scales of nine species, including taxa from Australia and Central and North America, were examined using scanning electron microscopy, paraffin carving, and transmission electron microscopy (whole mounts only). The surface morphology and internal anatomy of the scales exhibit considerable intra- and inter-specific variation. The structures that exhibit the most variation are (i) the plicae, small lateral ridges on the dorsal surface, which show variation in both morphology and pattern, and (ii) the rod-shaped, branched cuticular elements that occur within the lumina, which vary most dramatically in pattern. Scale morphology also varies regionally (i.e., with respect to location on the body) in most species. A comparison of the morphology of scales of Hamataliwa spp. with those of the striped lynx spider, Oxyopes salticus, and the green lynx spider, Peucetia viridans, suggests that scales may represent a useful phylogenetic character for understanding relationships both within and between genera in the Oxyopidae.

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Collins, D. M., G. W. De Lisle e D. M. Gabric. "Geographic distribution of restriction types ofMycobacterium bovisisolates from brush-tailed possums (Trichosurus vulpecula) in New Zealand". Journal of Hygiene 96, n. 3 (giugno 1986): 431–38. http://dx.doi.org/10.1017/s0022172400066201.

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SUMMARYDNA restriction endonuclease analysis was used for intra-specific typing ofMycobacterium bovisisolates from 83 brush-tailed possums (Trichosurus vulpecula) obtained between 1982 and 1984 from the three major regions in New Zealand with endemic bovine tuberculosis. All the isolates were found to be genetically very similar. Differentiation of the isolates into 33 restriction types was achieved by using high-resolution electrophoresis and the combined results from separate digestions with the restriction enzymesBstEII,PvuII andBclI. The typing system was entirely reproducible. Isolates of the same type were usually found in adjacent localities and were always limited to one of the three major regions. In some cases, isolates of the same type were found in both 1982 and 1984. The phenotypic significance of the small genetic differences identified between different isolates is unknown. The typing system will be useful for monitoring the transmission ofM. bovisto other species and the future spread of differentM. bovistypes through possum populations.

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RODRIGUEZ, N. M., Z. DE GUGLIELMO, M. A. BARRIOS, R. M. BARRIOS, O. ZERPA e M. D. FELICIANGELI. "Genetic homogeneity within Leishmania (L.) infantum isolated from human and dogs: the relationship with the sandfly fauna distribution in endemic areas of Nueva Esparta State, Venezuela". Parasitology 130, n. 6 (22 febbraio 2005): 611–19. http://dx.doi.org/10.1017/s0031182004007085.

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Leishmania infantum has been described as a highly polymorphic group of parasites, responsible for visceral leishmaniasis and cutaneous leishmaniasis. In this paper we report the life-cycle of L. (L.) infantum in an endemic area of visceral leishmaniasis in Venezuela, by using molecular diagnosis and characterization of parasites isolated from dogs, humans with visceral leishmaniasis and sand flies. The molecular characterization was carried out by use of kDNA restriction analysis, dot-blot hybridization with species-specific probes and RFLP of the PCR products. The results demonstrated that L. (L.) infantum is the parasite responsible for VL in the island. The parasites were revealed to be genetically homogeneous with no intra-specific differences between isolates from different individuals. The highest homology of the isolates was with L. (L.) infantum from the Old World rather than with L. (L.) chagasi from the New World. Additionally, we report the geographical distribution of Lutzomyia longipalpis, and the relationship with the transmission of L. (L.) infantum in the studied area.

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Schmitz, Nele, Gerald Koch, Hans Beeckman, Nico Koedam, Elisabeth M. R. Robert e Uwe Schmitt. "A Structural and Compositional Analysis of Intervessel pit Membranes in the Sapwood of some Mangrove Woods". IAWA Journal 33, n. 3 (2012): 243–56. http://dx.doi.org/10.1163/22941932-90000091.

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Intervessel pits are prominent wall structures involved in the water transport mechanism of land plants. The role of their intra-tree variation in the regulation of water transport, however, remains enigmatic. The hypothesis was tested that pit membrane thickness and degree of impregnation with phenolic substances increase along the stem axis with increasing tension on the water column as an adaptation to the higher risk for cavitation. Wood samples were taken at different heights from the mangrove tree Rhizophora mucronata growing at Gazi Bay (Kenya). Additional samples were taken along the stem radius to distinguish height from age effect, and from six other mangrove species growing in the same forest. Intervessel pit membranes were studied via transmission and scanning electron microscopy and cellular UV-microspectrophotometry. The hypothesis of pit membrane thickness and composition as a static adaptation to the hydrostatic conditions during vessel differentiation could be refuted. Instead, our findings point to a more dynamic pit membrane appearance with seasonal changes in thickness and chemical composition.

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Roberts, Scott C., Egon A. Ozer, Teresa Zembower e Chao Qi. "864. Whole Genome Sequencing is Unable to Track Candida auris Transmission". Open Forum Infectious Diseases 7, Supplement_1 (1 ottobre 2020): S470—S471. http://dx.doi.org/10.1093/ofid/ofaa439.1053.

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Abstract Background Candida auris (C. auris), an emerging yeast species, is often drug-resistant and has caused outbreaks in healthcare settings. Surging C. auris cases at our institution prompted whole genome sequencing (WGS) of patient and environmental specimens and comparison to local and international isolates. Methods WGS was performed on clinical and environmental isolates obtained from Northwestern Memorial Hospital (NMH) from June 2018 to December 2019. Genome sequences were compared against isolates from other institutions in the Chicagoland area obtained from a reference lab (ACL) and from the CDC. Two isolates underwent long-read sequencing on the Oxford Nanopore GridION platform to obtain closed genomes. WGS was performed on the remaining isolates with the Illumina MiSeq platform. Results Twenty isolates from NMH, five from ACL, and two from the CDC underwent WGS to yield 12.6 Mb genomes. Any two NMH isolates differed from each other by a maximum of 36 single nucleotide variants (SNV) (Figure 1). Two patients thought to be part of a transmission cluster (isolates CA06 and CA07), differed by 7 SNVs. No phylogenetic grouping between hospital systems across Chicagoland was observed. Isolates from room surfaces from a C. auris patient differed by 1-6 SNVs from each other and from 7-8 SNVs from the patient isolate. Samples taken from different body sites of another patient differed by 4-9 SNVs. Average SNV counts were lower among nosocomially acquired cases when compared to C. auris isolates present on admission (Figure 2). All NMH isolates were fluconazole sensitive, but a fluconazole resistant ACL isolate differed from a sensitive NMH isolate by only 4 SNVs. Figure 1: Phylogenetic tree of all NMH and ACL isolates with fluconazole sensitivities Figure 2: Observed pairwise SNP differences between nosocomial and POA strains Conclusion WGS of C. auris did not reveal identical isolates in any instance, even from the same patient or the patients and their environment. Generally, lower numbers of SNVs were observed for intra- versus inter-institutional isolates. More work is needed to determine the use, if any, of WGS in outbreak investigations. Disclosures All Authors: No reported disclosures

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McIntyre, Chloe L., Nick J. Knowles e Peter Simmonds. "Proposals for the classification of human rhinovirus species A, B and C into genotypically assigned types". Journal of General Virology 94, n. 8 (1 agosto 2013): 1791–806. http://dx.doi.org/10.1099/vir.0.053686-0.

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Human rhinoviruses (HRVs) frequently cause mild upper respiratory tract infections and more severe disease manifestations such as bronchiolitis and asthma exacerbations. HRV is classified into three species within the genus Enterovirus of the family Picornaviridae. HRV species A and B contain 75 and 25 serotypes identified by cross-neutralization assays, although the use of such assays for routine HRV typing is hampered by the large number of serotypes, replacement of virus isolation by molecular methods in HRV diagnosis and the poor or absent replication of HRV species C in cell culture. To address these problems, we propose an alternative, genotypic classification of HRV-based genetic relatedness analogous to that used for enteroviruses. Nucleotide distances between 384 complete VP1 sequences of currently assigned HRV (sero)types identified divergence thresholds of 13, 12 and 13 % for species A, B and C, respectively, that divided inter- and intra-type comparisons. These were paralleled by 10, 9.5 and 10 % thresholds in the larger dataset of >3800 VP4 region sequences. Assignments based on VP1 sequences led to minor revisions of existing type designations (such as the reclassification of serotype pairs, e.g. A8/A95 and A29/A44, as single serotypes) and the designation of new HRV types A101–106, B101–103 and C34–C51. A protocol for assignment and numbering of new HRV types using VP1 sequences and the restriction of VP4 sequence comparisons to type identification and provisional type assignments is proposed. Genotypic assignment and identification of HRV types will be of considerable value in the future investigation of type-associated differences in disease outcomes, transmission and epidemiology.

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Probst, Carolina, Anja Globig, Bent Knoll, Franz J. Conraths e Klaus Depner. "Behaviour of free ranging wild boar towards their dead fellows: potential implications for the transmission of African swine fever". Royal Society Open Science 4, n. 5 (maggio 2017): 170054. http://dx.doi.org/10.1098/rsos.170054.

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The behaviour of free ranging wild boar ( Sus scrofa ) towards carcasses of their conspecifics potentially infected with African swine fever (ASF) may significantly influence the course of an ASF epidemic. This study aims to better understand the behaviour of wild boar towards their dead fellows. Thirty-two wild boar carcasses on nine study sites in northeast Germany were monitored under field conditions by photo-trapping from October 2015 until October 2016. During this period, a total of 122 160 pictures were taken, thereof 16 111 pictures of wild boar. In both winter and summer, wild boar seemed to be particularly interested in the soil next to and underneath the carcasses. About one third of the visits of wild boar led to direct contact with dead conspecifics. The contacts consisted mostly in sniffing and poking on the carcass. Under the given ecological and climatic conditions, there was no evidence for intra-species scavenging. However, piglets were observed several times chewing bare bones once skeletonization of the carcasses was complete. It must be assumed that all these types of contact may represent a risk of transmission. Both the high tenacity of ASF virus and the long time wild boar carcasses can remain in the environment, allow the persistence of the virus for several months or even years. We therefore consider the rapid detection and removal (or destruction on the spot) of contaminated carcasses as an important control measure against ASF in wild boar.

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Southgate, Joel A., Matthew J. Bull, Clare M. Brown, Joanne Watkins, Sally Corden, Benjamin Southgate, Catherine Moore e Thomas R. Connor. "Influenza classification from short reads with VAPOR facilitates robust mapping pipelines and zoonotic strain detection for routine surveillance applications". Bioinformatics 36, n. 6 (6 novembre 2019): 1681–88. http://dx.doi.org/10.1093/bioinformatics/btz814.

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Abstract Motivation Influenza viruses represent a global public health burden due to annual epidemics and pandemic potential. Due to a rapidly evolving RNA genome, inter-species transmission, intra-host variation, and noise in short-read data, reads can be lost during mapping, and de novo assembly can be time consuming and result in misassembly. We assessed read loss during mapping and designed a graph-based classifier, VAPOR, for selecting mapping references, assembly validation and detection of strains of non-human origin. Results Standard human reference viruses were insufficient for mapping diverse influenza samples in simulation. VAPOR retrieved references for 257 real whole-genome sequencing samples with a mean of >99.8% identity to assemblies, and increased the proportion of mapped reads by up to 13.3% compared to standard references. VAPOR has the potential to improve the robustness of bioinformatics pipelines for surveillance and could be adapted to other RNA viruses. Availability and implementation VAPOR is available at https://github.com/connor-lab/vapor. Supplementary information Supplementary data are available at Bioinformatics online.

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