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Sample records for lepidopteran host ranges

  1. Baculovirus cyclobutane pyrimidine dimer photolyases show a close relationship with lepidopteran host homologues.

    PubMed

    Biernat, M A; Ros, V I D; Vlak, J M; van Oers, M M

    2011-08-01

    Cyclobutane pyrimidine dimer (CPD) photolyases repair ultraviolet (UV)-induced DNA damage using blue light. To get insight in the origin of baculovirus CPD photolyase (phr) genes, homologues in the lepidopteran insects Chrysodeixis chalcites, Spodoptera exigua and Trichoplusia ni were identified and characterized. Lepidopteran and baculovirus phr genes each form a monophyletic group, and together form a well-supported clade within the insect photolyases. This suggests that baculoviruses obtained their phr genes from an ancestral lepidopteran insect host. A likely evolutionary scenario is that a granulovirus, Spodoptera litura GV or a direct ancestor, obtained a phr gene. Subsequently, it was horizontally transferred from this granulovirus to several group II nucleopolyhedroviruses (NPVs), including those that infect noctuids of the Plusiinae subfamily. PMID:21477200

  2. Extensive transcription analysis of the Hyposoter didymator Ichnovirus genome in permissive and non-permissive lepidopteran host species.

    PubMed

    Dorémus, Tristan; Cousserans, François; Gyapay, Gabor; Jouan, Véronique; Milano, Patricia; Wajnberg, Eric; Darboux, Isabelle; Cônsoli, Fernando Luis; Volkoff, Anne-Nathalie

    2014-01-01

    Ichnoviruses are large dsDNA viruses that belong to the Polydnaviridae family. They are specifically associated with endoparasitic wasps of the family Ichneumonidae and essential for host parasitization by these wasps. We sequenced the Hyposoter didymator Ichnovirus (HdIV) encapsidated genome for further analysis of the transcription pattern of the entire set of HdIV genes following the parasitization of four different lepidopteran host species. The HdIV genome was found to consist of at least 50 circular dsDNA molecules, carrying 135 genes, 98 of which formed 18 gene families. The HdIV genome had general features typical of Ichnovirus (IV) genomes and closely resembled that of the IV carried by Hyposoter fugitivus. Subsequent transcriptomic analysis with Illumina technology during the course of Spodoptera frugiperda parasitization led to the identification of a small subset of less than 30 genes with high RPKM values in permissive hosts, consisting with these genes encoding crucial virulence proteins. Comparisons of HdIV expression profiles between host species revealed differences in transcript levels for given HdIV genes between two permissive hosts, S. frugiperda and Pseudoplusia includens. However, we found no evident intrafamily gene-specific transcription pattern consistent with the presence of multigenic families within IV genomes reflecting an ability of the wasps concerned to exploit different host species. Interestingly, in two non-permissive hosts, Mamestra brassiccae and Anticarsia gemmatalis (most of the parasitoid eggs were eliminated by the host cellular immune response), HdIV genes were generally less strongly transcribed than in permissive hosts. This suggests that successful parasitism is dependent on the expression of given HdIV genes exceeding a particular threshold value. These results raise questions about the mecanisms involved in regulating IV gene expression according to the nature of the lepidopteran host species encountered. PMID

  3. Extensive Transcription Analysis of the Hyposoter didymator Ichnovirus Genome in Permissive and Non-Permissive Lepidopteran Host Species

    PubMed Central

    Dorémus, Tristan; Cousserans, François; Gyapay, Gabor; Jouan, Véronique; Milano, Patricia; Wajnberg, Eric; Darboux, Isabelle; Cônsoli, Fernando Luis; Volkoff, Anne-Nathalie

    2014-01-01

    Ichnoviruses are large dsDNA viruses that belong to the Polydnaviridae family. They are specifically associated with endoparasitic wasps of the family Ichneumonidae and essential for host parasitization by these wasps. We sequenced the Hyposoter didymator Ichnovirus (HdIV) encapsidated genome for further analysis of the transcription pattern of the entire set of HdIV genes following the parasitization of four different lepidopteran host species. The HdIV genome was found to consist of at least 50 circular dsDNA molecules, carrying 135 genes, 98 of which formed 18 gene families. The HdIV genome had general features typical of Ichnovirus (IV) genomes and closely resembled that of the IV carried by Hyposoter fugitivus. Subsequent transcriptomic analysis with Illumina technology during the course of Spodoptera frugiperda parasitization led to the identification of a small subset of less than 30 genes with high RPKM values in permissive hosts, consisting with these genes encoding crucial virulence proteins. Comparisons of HdIV expression profiles between host species revealed differences in transcript levels for given HdIV genes between two permissive hosts, S. frugiperda and Pseudoplusia includens. However, we found no evident intrafamily gene-specific transcription pattern consistent with the presence of multigenic families within IV genomes reflecting an ability of the wasps concerned to exploit different host species. Interestingly, in two non-permissive hosts, Mamestra brassiccae and Anticarsia gemmatalis (most of the parasitoid eggs were eliminated by the host cellular immune response), HdIV genes were generally less strongly transcribed than in permissive hosts. This suggests that successful parasitism is dependent on the expression of given HdIV genes exceeding a particular threshold value. These results raise questions about the mecanisms involved in regulating IV gene expression according to the nature of the lepidopteran host species encountered. PMID

  4. Parasitism and survival rate of Diadegma fenestrale (Hymenoptera: Ichneumonidae) and DfIV gene expression patterns in two lepidopteran hosts.

    PubMed

    Kim, Ju Il; Kwon, Min; Lee, Si Hyeock; Kim, Yonggyun

    2015-04-17

    The genus Diadegma is a well-known parasitoid group and some are known to have symbiotic virus, polydnavirus (PDV). A novel IV was discovered from the calyx of Diadegma fenestrale female and sequenced its genome. D. fenestrale has more than two hosts, including potato tuber moth (PTM) and diamondback moth (DBM). D. fenestrale preferred PTM to DBM as hosts based on the oviposition and survival rate. Nevertheless, the developmental period and morphology of D. fenestrale were not significantly different between PTM and DBM. We compared DfIV gene expression patterns between PTM and DBM under various conditions to understand the phenomena. DfIV genes were more widely expressed in PTM with large numbers than in DBM after parasitized by D. fenestrale, particularly at the initial point. They showed differential expression patterns between two lepidopteran hosts. This DfIV gene expression plasticity showed a dependency on the lepidopteran host species and parasitization time, suggesting that it may contribute to increase the parasitoid survival rate. This might be one of the key elements that determine the symbiotic relationship between PDV and parasitoid. PMID:25769948

  5. Permissiveness of lepidopteran hosts is linked to differential expression of bracovirus genes.

    PubMed

    Bitra, Kavita; Burke, Gaelen R; Strand, Michael R

    2016-05-01

    Polydnaviruses in the genus Bracovirus (BV) are associated with parasitoid wasps in the family Braconidae. BV-carrying wasps rely on their associated viruses to parasitize permissive hosts but also occasionally oviposit into host species that are non-permissive. Here, we studied Microplitis demolitor and M. demolitor bracovirus (MdBV) in Chrysodeixis includens, a permissive host, and Trichoplusia ni, which is usually non-permissive. M. demolitor laid eggs and injected MdBV into both hosts but almost no wasp offspring developed in T. ni. MdBV DNA similarly persisted in both host species, but deep sequencing data showed that transcript abundance for most viral genes was higher in C. includens than T. ni. Overall, our results identify lower expression of MdBV genes as an important factor in the non-permissiveness of T. ni. However, certain genes with functions in immunosuppression were sufficiently expressed to have similar effect in T. ni and C. includens. PMID:27011224

  6. A comprehensive transcriptome and immune-gene repertoire of the lepidopteran model host Galleria mellonella

    PubMed Central

    2011-01-01

    Background The larvae of the greater wax moth Galleria mellonella are increasingly used (i) as mini-hosts to study pathogenesis and virulence factors of prominent bacterial and fungal human pathogens, (ii) as a whole-animal high throughput infection system for testing pathogen mutant libraries, and (iii) as a reliable host model to evaluate the efficacy of antibiotics against human pathogens. In order to compensate for the lack of genomic information in Galleria, we subjected the transcriptome of different developmental stages and immune-challenged larvae to next generation sequencing. Results We performed a Galleria transcriptome characterization on the Roche 454-FLX platform combined with traditional Sanger sequencing to obtain a comprehensive transcriptome. To maximize sequence diversity, we pooled RNA extracted from different developmental stages, larval tissues including hemocytes, and from immune-challenged larvae and normalized the cDNA pool. We generated a total of 789,105 pyrosequencing and 12,032 high-quality Sanger EST sequences which clustered into 18,690 contigs with an average length of 1,132 bases. Approximately 40% of the ESTs were significantly similar (E ≤ e-03) to proteins of other insects, of which 45% have a reported function. We identified a large number of genes encoding proteins with established functions in immunity related sensing of microbial signatures and signaling, as well as effector molecules such as antimicrobial peptides and inhibitors of microbial proteinases. In addition, we found genes known as mediators of melanization or contributing to stress responses. Using the transcriptomic data, we identified hemolymph peptides and proteins induced upon immune challenge by 2D-gelelectrophoresis combined with mass spectrometric analysis. Conclusion Here, we have developed extensive transcriptomic resources for Galleria. The data obtained is rich in gene transcripts related to immunity, expanding remarkably our knowledge about immune and

  7. Parasite host range and the evolution of host resistance.

    PubMed

    Gorter, F A; Hall, A R; Buckling, A; Scanlan, P D

    2015-05-01

    Parasite host range plays a pivotal role in the evolution and ecology of hosts and the emergence of infectious disease. Although the factors that promote host range and the epidemiological consequences of variation in host range are relatively well characterized, the effect of parasite host range on host resistance evolution is less well understood. In this study, we tested the impact of parasite host range on host resistance evolution. To do so, we used the host bacterium Pseudomonas fluorescens SBW25 and a diverse suite of coevolved viral parasites (lytic bacteriophage Φ2) with variable host ranges (defined here as the number of host genotypes that can be infected) as our experimental model organisms. Our results show that resistance evolution to coevolved phages occurred at a much lower rate than to ancestral phage (approximately 50% vs. 100%), but the host range of coevolved phages did not influence the likelihood of resistance evolution. We also show that the host range of both single parasites and populations of parasites does not affect the breadth of the resulting resistance range in a naïve host but that hosts that evolve resistance to single parasites are more likely to resist other (genetically) more closely related parasites as a correlated response. These findings have important implications for our understanding of resistance evolution in natural populations of bacteria and viruses and other host-parasite combinations with similar underlying infection genetics, as well as the development of phage therapy. PMID:25851735

  8. Host range and infectivity of Heterorhabditis bacteriophora (Heterorhabditidae) from Ukraine.

    PubMed

    Stefanovska, T; Pidlishyuk, V; Kaya, H

    2008-01-01

    Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis (Rhabditida: Steinernematidae and Heterorhabditidae, respectively) represent a most promising group of pathogens that are lethal to many soil-inhabiting insects. Ukraine has Lagged behind of Eastern European countries in apply studies of entomopathogenic nematodes. Recently, Heterorhabditis bacteriophora were extracted from soils in the Central Forest Steppe areas of Ukraine using Galleria mellonella traps and identified with PCR. Infection were carried out in Laboratory to determine the host range, specificity and virulence of H. bacteriophora ukr. isol. It was shown that this nematode infected a wide range of insect species. Of the 14 tested insects which belong to four orders , all were susceptible to nematode species with mortality ranges from 12 to 96%. Infectivity did differ within each host. The most favorable hosts were Lepidopterans and coleopterans. The virulence of H. bacteriophora was measured by one-on-one bioassay. H. bacteriophora caused 60% mortality at 5 infective juveniles per Galleria mellonella larvae. LD50 values were 3 +/- 1. Nematodes reproduced and completed their cycle with IJ production in all four orders. H. bacteriophora ukr. isoL.. developed preferably in immature insect stage. Percentage of emergence form cadavers that produced progeny were higher for Lepidoptera and Coleopteran species. Progeny production were not related to the biomass of the cadavers. Because of wide range of insect species Heterhorobditis bacteriophora ukr. isol. has potential for control economically important pests in Ukraine. Further studies should be focused at ecological characterization of isolated H. bacteriophora and carrying out survey of entomopathogenic nematodes. PMID:19226814

  9. Electroantennogram (EAG) responses of Microplitis croceipes and Cotesia marginiventris and their lepidopteran hosts to a wide array of odor stimuli: correlation between EAG response and degree of host specificity?

    PubMed

    Ngumbi, Esther; Chen, Li; Fadamiro, Henry

    2010-09-01

    In order to test whether the electroantennogram (EAG) response spectrum of an insect correlates to its degree of host specificity, we recorded EAG responses of two parasitoid species with different degrees of host specificity, Microplitis croceipes (specialist) and Cotesia marginiventris (generalist), to a wide array of odor stimuli including compounds representing green leaf volatiles (GLVs), herbivore-induced plant volatiles (HIPV), ecologically irrelevant (not used by the parasitoid species and their hosts for host location) plant volatiles, and host-specific odor stimuli (host sex pheromones, and extracts of host caterpillar body and frass). We also tested the EAG responses of female moths of the caterpillar hosts of the parasitoids, Heliothis virescens and Spodoptera exigua, to some of the odor stimuli. We hypothesized that the specialist parasitoid will have a narrower EAG response spectrum than the generalist, and that the two lepidopteran species, which are similar in their host plant use, will show similar EAG response spectra to plant volatiles. As predicted, the specialist parasitoid showed greater EAG responses than the generalist to host-specific odor and one HIPV (cis-3-hexenyl butyrate), whereas the generalist showed relatively greater EAG responses to the GLVs and unrelated plant volatiles. We detected no differences in the EAG responses of H. virescens and S. exigua to any of the tested odor. PMID:20371248

  10. Expression of Early Immune-Response Genes in Lepidopteran Host are Suppressed by Venom From an Endoparasitoid, Pteromalus puparum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationships between parasitoids and their insect hosts have attracted attention at two levels. First, the basic biology of host-parasitoid interactions is of fundamental interest. Second, parasitoids have tremendous potential as biological control agents in sustainable agriculture programs. Pt...

  11. Host Range and Emerging and Reemerging Pathogens

    PubMed Central

    Gowtage-Sequeria, Sonya

    2005-01-01

    An updated literature survey identified 1,407 recognized species of human pathogen, 58% of which are zoonotic. Of the total, 177 are regarded as emerging or reemerging. Zoonotic pathogens are twice as likely to be in this category as are nonzoonotic pathogens. Emerging and reemerging pathogens are not strongly associated with particular types of nonhuman hosts, but they are most likely to have the broadest host ranges. Emerging and reemerging zoonoses are associated with a wide range of drivers, but changes in land use and agriculture and demographic and societal changes are most commonly cited. However, although zoonotic pathogens do represent the most likely source of emerging and reemerging infectious disease, only a small minority have proved capable of causing major epidemics in the human population. PMID:16485468

  12. When History Repeats Itself: Exploring the Genetic Architecture of Host-Plant Adaptation in Two Closely Related Lepidopteran Species

    PubMed Central

    Alexandre, Hermine; Ponsard, Sergine; Bourguet, Denis; Vitalis, Renaud; Audiot, Philippe; Cros-Arteil, Sandrine; Streiff, Réjane

    2013-01-01

    The genus Ostrinia includes two allopatric maize pests across Eurasia, namely the European corn borer (ECB, O. nubilalis) and the Asian corn borer (ACB, O. furnacalis). A third species, the Adzuki bean borer (ABB, O. scapulalis), occurs in sympatry with both the ECB and the ACB. The ABB mostly feeds on native dicots, which probably correspond to the ancestral host plant type for the genus Ostrinia. This situation offers the opportunity to characterize the two presumably independent adaptations or preadaptations to maize that occurred in the ECB and ACB. In the present study, we aimed at deciphering the genetic architecture of these two adaptations to maize, a monocot host plant recently introduced into Eurasia. To this end, we performed a genome scan analysis based on 684 AFLP markers in 12 populations of ECB, ACB and ABB. We detected 2 outlier AFLP loci when comparing French populations of the ECB and ABB, and 9 outliers when comparing Chinese populations of the ACB and ABB. These outliers were different in both countries, and we found no evidence of linkage disequilibrium between any two of them. These results suggest that adaptation or preadaptation to maize relies on a different genetic architecture in the ECB and ACB. However, this conclusion must be considered in light of the constraints inherent to genome scan approaches and of the intricate evolution of adaptation and reproductive isolation in the Ostrinia spp. complex. PMID:23874914

  13. Host range, host specificity and hypothesized host shift events among viruses of lower vertebrates

    PubMed Central

    2011-01-01

    The successful replication of a viral agent in a host is a complex process that often leads to a species specificity of the virus and can make interspecies transmission difficult. Despite this difficulty, natural host switch seems to have been frequent among viruses of lower vertebrates, especially fish viruses, since there are several viruses known to be able to infect a wide range of species. In the present review we will focus on well documented reports of broad host range, variations in host specificity, and host shift events hypothesized for viruses within the genera Ranavirus, Novirhabdovirus, Betanodavirus, Isavirus, and some herpesvirus. PMID:21592358

  14. Ecological consequences of ingestion of Bacillus cereus on Bacillus thuringiensis infections and on the gut flora of a lepidopteran host.

    PubMed

    Raymond, Ben; Lijek, Rebeccah S; Griffiths, Robert I; Bonsall, Michael B

    2008-09-01

    The Bacillus cereus group comprises a diverse array of non-pathogenic bacteria as well as pathogens such as Bacillus thuringiensis. Their spores are found together in soil and leaves and are therefore likely to commonly interact within hosts. Mixed infections of pathogenic B. thuringiensis and non-pathogenic strains have been little studied, despite their potential impact on biological control and the evolutionary ecology of virulence. Antibiotic secreting strains of B. cereus have been shown to be able to synergize B. thuringiensis (Bt) infections. We explored the ecology of these mixed infections more broadly in the diamondback moth (DBM). We tested whether antibiotic-expressing B. cereus can synergize Bt infections initiated with spores, investigated whether ingestion of antibiotic-expressing B. cereus had any consequences for the larval gut flora and whether synergistic interactions with B. cereus increase Bt reproduction. Ingestion of high-antibiotic secreting B. cereus synergized infections of B. thuringiensis in diamondback moth larvae, but at a lower level than previously reported. Coinfection also increased slightly the number of Bt spores found in cadavers. Culture independent analysis of gut homogenates indicated that ingestion of an antibiotic-expressing strain of B. cereus reduced the abundance of the gut flora and led to gut communities being dominated bacteria with DGGE profiles very similar to pure B. cereus cultures. Ingestion of B. cereus, regardless of genotype, reduced densities of an enteric isolate of Enterobacter sp. These findings support the hypothesis that antibiotic secretion in the gut synergizes B. thuringiensis infections by reducing the abundance of the commensal gut flora and facilitating invasion by bacteria in the B. cereus group. PMID:18533180

  15. In vitro host range of feline morbillivirus

    PubMed Central

    SAKAGUCHI, Shoichi; KOIDE, Rie; MIYAZAWA, Takayuki

    2015-01-01

    Feline morbillivirus (FmoPV) is an emerging virus in cats, which is associated with tubulointerstitial nephritis. To study the in vitro host range of FmoPV, we inoculated FmoPV strain SS1 to 32 cell lines originated from 13 species and cultured for 2 weeks, followed by RNA extraction and reverse-transcription-polymerase chain reaction for FmoPV detection. As a result, only cell lines derived from cats and African green monkeys were susceptible to FmoPV. FmoPV infects diverse feline cell lines: epithelial, fibroblastic, lymphoid and glial cells. These results indicate that the receptor (s) for FmoPV are ubiquitously expressed in cats. No infectivity of FmoPV was observed in human cell lines, which suggests least threatening of cross-species transmission of FmoPV from cats to humans. PMID:26027844

  16. Poxviruses and the Evolution of Host Range and Virulence

    PubMed Central

    Haller, Sherry L.; Peng, Chen; McFadden, Grant; Rothenburg, Stefan

    2013-01-01

    Poxviruses as a group can infect a large number of animals. However, at the level of individual viruses, even closely related poxviruses display highly diverse host ranges and virulence. For example, variola virus, the causative agent of smallpox, is human-specific and highly virulent only to humans, whereas related cowpox viruses naturally infect a broad spectrum of animals and only cause relatively mild disease in humans. The successful replication of poxviruses depends on their effective manipulation of the host antiviral responses, at the cellular-, tissue- and species-specific levels, which constitutes a molecular basis for differences in poxvirus host range and virulence. A number of poxvirus genes have been identified that possess host range function in experimental settings, and many of these host range genes target specific antiviral host pathways. Herein, we review the biology of poxviruses with a focus on host range, zoonotic infections, virulence, genomics and host range genes as well as the current knowledge about the function of poxvirus host range factors and how their interaction with the host innate immune system contributes to poxvirus host range and virulence. We further discuss the evolution of host range and virulence in poxviruses as well as host switches and potential poxvirus threats for human and animal health. PMID:24161410

  17. Host Range Specificity in Verticillium dahliae.

    PubMed

    Bhat, R G; Subbarao, K V

    1999-12-01

    ABSTRACT Verticillium dahliae isolates from artichoke, bell pepper, cabbage, cauliflower, chili pepper, cotton, eggplant, lettuce, mint, potato, strawberry, tomato, and watermelon and V. albo-atrum from alfalfa were evaluated for their pathogenicity on all 14 hosts. One-month-old seedlings were inoculated with a spore suspension of about 10(7) conidia per ml using a root-dip technique and incubated in the greenhouse. Disease incidence and severity, plant height, and root and shoot dry weights were recorded 6 weeks after inoculation. Bell pepper, cabbage, cauliflower, cotton, eggplant, and mint isolates exhibited host specificity and differential pathogenicity on other hosts, whereas isolates from artichoke, lettuce, potato, strawberry, tomato, and watermelon did not. Bell pepper was resistant to all Verticillium isolates except isolates from bell pepper and eggplant. Thus, host specificity exists in some isolates of V. dahliae. The same isolates were characterized for vegetative compatibility groups (VCGs) through complementation of nitrate nonutilizing (nit) mutants. Cabbage and cauliflower isolates did not produce nit mutants. The isolate from cotton belonged to VCG 1; isolates from bell pepper, eggplant, potato, and tomato, to VCG 4; and the remaining isolates, to VCG 2. These isolates were also analyzed using the random amplified polymorphic DNA (RAPD) method. Forty random primers were screened, and eighteen of them amplified DNA from Verticillium. Based on RAPD banding patterns, cabbage and cauliflower isolates formed a unique group, distinct from other V. dahliae and V. albo-atrum groups. Minor genetic variations were observed among V. dahliae isolates from other hosts, regardless of whether they were host specific or not. There was no correlation among pathogenicity, VCGs, and RAPD banding patterns. Even though the isolates belonged to different VCGs, they shared similar RAPD profiles. These results suggest that management of Verticillium wilt in some crops

  18. GENETICS OF HOST RANGE IN LEPIDOPTERA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic basis of complex, ecologically relevant traits is not well known for any organism. The question is particularly compelling where closely-related species have diverged radically in their adaptation to the environment. Differences in host plant use among moths and butterflies often provi...

  19. Evolution of host range in Coleosporium ipomoeae, a plant pathogen with multiple hosts.

    PubMed

    Chappell, Thomas M; Rausher, Mark D

    2016-05-10

    Plants and their pathogens coevolve locally. Previous investigations of one host-one pathogen systems have demonstrated that natural selection favors pathogen genotypes that are virulent on a broad range of host genotypes. In the present study, we examine a system consisting of one pathogen species that infects three host species in the morning glory genus Ipomoea. We show that many pathogen genotypes can infect two or three of the host species when tested on plants from nonlocal communities. By contrast, pathogen genotypes are highly host-specific, infecting only one host species, when tested on host species from the local community. This pattern indicates that within-community evolution narrows the host breadth of pathogen genotypes. Possible evolutionary mechanisms include direct selection for narrow host breadth due to costs of virulence and evolution of ipomoea resistance in the host species. PMID:27114547

  20. Scale insect host ranges are broader in the tropics.

    PubMed

    Hardy, Nate B; Peterson, Daniel A; Normark, Benjamin B

    2015-12-01

    The specificity of the interactions between plants and their consumers varies considerably. The evolutionary and ecological factors underlying this variation are unclear. Several potential explanatory factors vary with latitude, for example plant species richness and the intensity of herbivory. Here, we use comparative phylogenetic methods to test the effect of latitude on host range in scale insects. We find that, on average, scale insects that occur in lower latitudes are more polyphagous. This result is at odds with the general pattern of greater host-plant specificity of insects in the tropics. We propose that this disparity reflects a high cost for host specificity in scale insects, stemming from unusual aspects of scale insect life history, for example, passive wind-driven dispersal. More broadly, the strong evidence for pervasive effects of geography on host range across insect groups stands in stark contrast to the weak evidence for constraints on host range due to genetic trade-offs. PMID:26701757

  1. An Experimental Host Range of Triticum Mosaic Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Triticum mosaic virus (TriMV) is a newly discovered virus isolated from wheat. This study was conducted to determine an experimental host range for TriMV and identify species that could serve as differential hosts for isolating TriMV from Wheat streak mosaic virus (WSMV). Plants tested were mechan...

  2. Cooperative secretions facilitate host range expansion in bacteria

    PubMed Central

    McNally, Luke; Viana, Mafalda; Brown, Sam P.

    2014-01-01

    The majority of emergent human pathogens are zoonotic in origin, that is, they can transmit to humans from other animals. Understanding the factors underlying the evolution of pathogen host range is therefore of critical importance in protecting human health. There are two main evolutionary routes to generalism: organisms can tolerate multiple environments or they can modify their environments to forms to which they are adapted. Here we use a combination of theory and a phylogenetic comparative analysis of 191 pathogenic bacterial species to show that bacteria use cooperative secretions that modify their environment to extend their host range and infect multiple host species. Our results suggest that cooperative secretions are key determinants of host range in bacteria, and that monitoring for the acquisition of secreted proteins by horizontal gene transfer can help predict emerging zoonoses. PMID:25091146

  3. Host compatibility rather than vector–host-encounter rate determines the host range of avian Plasmodium parasites

    PubMed Central

    Medeiros, Matthew C. I.; Hamer, Gabriel L.; Ricklefs, Robert E.

    2013-01-01

    Blood-feeding arthropod vectors are responsible for transmitting many parasites between vertebrate hosts. While arthropod vectors often feed on limited subsets of potential host species, little is known about the extent to which this influences the distribution of vector-borne parasites in some systems. Here, we test the hypothesis that different vector species structure parasite–host relationships by restricting access of certain parasites to a subset of available hosts. Specifically, we investigate how the feeding patterns of Culex mosquito vectors relate to distributions of avian malaria parasites among hosts in suburban Chicago, IL, USA. We show that Plasmodium lineages, defined by cytochrome b haplotypes, are heterogeneously distributed across avian hosts. However, the feeding patterns of the dominant vectors (Culex restuans and Culex pipiens) are similar across these hosts, and do not explain the distributions of Plasmodium parasites. Phylogenetic similarity of avian hosts predicts similarity in their Plasmodium parasites. This effect was driven primarily by the general association of Plasmodium parasites with particular host superfamilies. Our results suggest that a mosquito-imposed encounter rate does not limit the distribution of avian Plasmodium parasites across hosts. This implies that compatibility between parasites and their avian hosts structure Plasmodium host range. PMID:23595266

  4. Transcriptome dynamics of a broad host-range cyanophage and its hosts.

    PubMed

    Doron, Shany; Fedida, Ayalla; Hernández-Prieto, Miguel A; Sabehi, Gazalah; Karunker, Iris; Stazic, Damir; Feingersch, Roi; Steglich, Claudia; Futschik, Matthias; Lindell, Debbie; Sorek, Rotem

    2016-06-01

    Cyanobacteria are highly abundant in the oceans and are constantly exposed to lytic viruses. The T4-like cyanomyoviruses are abundant in the marine environment and have broad host-ranges relative to other cyanophages. It is currently unknown whether broad host-range phages specifically tailor their infection program for each host, or employ the same program irrespective of the host infected. Also unknown is how different hosts respond to infection by the same phage. Here we used microarray and RNA-seq analyses to investigate the interaction between the Syn9 T4-like cyanophage and three phylogenetically, ecologically and genomically distinct marine Synechococcus strains: WH7803, WH8102 and WH8109. Strikingly, Syn9 led a nearly identical infection and transcriptional program in all three hosts. Different to previous assumptions for T4-like cyanophages, three temporally regulated gene expression classes were observed. Furthermore, a novel regulatory element controlled early-gene transcription, and host-like promoters drove middle gene transcription, different to the regulatory paradigm for T4. Similar results were found for the P-TIM40 phage during infection of Prochlorococcus NATL2A. Moreover, genomic and metagenomic analyses indicate that these regulatory elements are abundant and conserved among T4-like cyanophages. In contrast to the near-identical transcriptional program employed by Syn9, host responses to infection involved host-specific genes primarily located in hypervariable genomic islands, substantiating islands as a major axis of phage-cyanobacteria interactions. Our findings suggest that the ability of broad host-range phages to infect multiple hosts is more likely dependent on the effectiveness of host defense strategies than on differential tailoring of the infection process by the phage. PMID:26623542

  5. HOST PLANT UTILIZATION, HOST RANGE OSCILLATIONS AND DIVERSIFICATION IN NYMPHALID BUTTERFLIES: A PHYLOGENETIC INVESTIGATION

    PubMed Central

    Nylin, Sören; Slove, Jessica; Janz, Niklas

    2014-01-01

    It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the “oscillation hypothesis.” In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies. PMID:24372598

  6. BLUP, a new paradigm in host-range determination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently best linear unbiased predictors (BLUPs) were used to determine the probable host-range of two plant pathogens proposed for classical biological control of Russian thistle. BLUPs were derived with mixed model equations incorporating disease ratings and relationship matrices computed from ge...

  7. Genome characteristics of facultatively symbiotic Frankia sp. strains reflect host range and host plant biogeography.

    PubMed

    Normand, Philippe; Lapierre, Pascal; Tisa, Louis S; Gogarten, Johann Peter; Alloisio, Nicole; Bagnarol, Emilie; Bassi, Carla A; Berry, Alison M; Bickhart, Derek M; Choisne, Nathalie; Couloux, Arnaud; Cournoyer, Benoit; Cruveiller, Stephane; Daubin, Vincent; Demange, Nadia; Francino, Maria Pilar; Goltsman, Eugene; Huang, Ying; Kopp, Olga R; Labarre, Laurent; Lapidus, Alla; Lavire, Celine; Marechal, Joelle; Martinez, Michele; Mastronunzio, Juliana E; Mullin, Beth C; Niemann, James; Pujic, Pierre; Rawnsley, Tania; Rouy, Zoe; Schenowitz, Chantal; Sellstedt, Anita; Tavares, Fernando; Tomkins, Jeffrey P; Vallenet, David; Valverde, Claudio; Wall, Luis G; Wang, Ying; Medigue, Claudine; Benson, David R

    2007-01-01

    Soil bacteria that also form mutualistic symbioses in plants encounter two major levels of selection. One occurs during adaptation to and survival in soil, and the other occurs in concert with host plant speciation and adaptation. Actinobacteria from the genus Frankia are facultative symbionts that form N(2)-fixing root nodules on diverse and globally distributed angiosperms in the "actinorhizal" symbioses. Three closely related clades of Frankia sp. strains are recognized; members of each clade infect a subset of plants from among eight angiosperm families. We sequenced the genomes from three strains; their sizes varied from 5.43 Mbp for a narrow host range strain (Frankia sp. strain HFPCcI3) to 7.50 Mbp for a medium host range strain (Frankia alni strain ACN14a) to 9.04 Mbp for a broad host range strain (Frankia sp. strain EAN1pec.) This size divergence is the largest yet reported for such closely related soil bacteria (97.8%-98.9% identity of 16S rRNA genes). The extent of gene deletion, duplication, and acquisition is in concert with the biogeographic history of the symbioses and host plant speciation. Host plant isolation favored genome contraction, whereas host plant diversification favored genome expansion. The results support the idea that major genome expansions as well as reductions can occur in facultative symbiotic soil bacteria as they respond to new environments in the context of their symbioses. PMID:17151343

  8. Generating a host range-expanded recombinant baculovirus

    PubMed Central

    Wu, Chunfeng; Deng, Zihao; Long, Zhao; Cai, Yi; Ying, Zhongfu; Yin, Hanqi; Yuan, Meijin; Clem, Rollie J.; Yang, Kai; Pang, Yi

    2016-01-01

    As baculoviruses usually have a narrow insecticidal spectrum, knowing the mechanisms by which they control the host-range is prerequisite for improvement of their applications as pesticides. In this study, from supernatant of culture cells transfected with DNAs of an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) mutant lacking the antiapoptotic gene p35 (vAc∆P35) and a cosmid representing a fragment of Spodoptera exigua nucleopolyhedrovirus (SeMNPV), a viral strain was plaque-purified and named vAcRev. vAcRev had a broader host range than either vAc∆P35 or SeMNPV parental virus, being able to infect not only the permissive hosts of its parental viruses but also a nonpermissive host (Spodoptera litura). Genome sequencing indicated that vAcRev comprises a mixture of two viruses with different circular dsDNA genomes. One virus contains a genome similar to vAc∆P35, while in the other viral genome, a 24.4 kbp-fragment containing 10 essential genesis replaced with a 4 kbp-fragment containing three SeMNPV genes including a truncated Se-iap3 gene. RNA interference and ectopic expression assays found that Se-iap3 is responsible for the host range expansion of vAcRev, suggesting that Se-iap3 inhibits the progression of apoptosis initiated by viral infection and promotes viral propagation in hosts both permissive and non-permissive for AcMNPV and SeMNPV. PMID:27321273

  9. Generating a host range-expanded recombinant baculovirus.

    PubMed

    Wu, Chunfeng; Deng, Zihao; Long, Zhao; Cai, Yi; Ying, Zhongfu; Yin, Hanqi; Yuan, Meijin; Clem, Rollie J; Yang, Kai; Pang, Yi

    2016-01-01

    As baculoviruses usually have a narrow insecticidal spectrum, knowing the mechanisms by which they control the host-range is prerequisite for improvement of their applications as pesticides. In this study, from supernatant of culture cells transfected with DNAs of an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) mutant lacking the antiapoptotic gene p35 (vAc(∆P35)) and a cosmid representing a fragment of Spodoptera exigua nucleopolyhedrovirus (SeMNPV), a viral strain was plaque-purified and named vAcRev. vAcRev had a broader host range than either vAc(∆P35) or SeMNPV parental virus, being able to infect not only the permissive hosts of its parental viruses but also a nonpermissive host (Spodoptera litura). Genome sequencing indicated that vAcRev comprises a mixture of two viruses with different circular dsDNA genomes. One virus contains a genome similar to vAc(∆P35), while in the other viral genome, a 24.4 kbp-fragment containing 10 essential genesis replaced with a 4 kbp-fragment containing three SeMNPV genes including a truncated Se-iap3 gene. RNA interference and ectopic expression assays found that Se-iap3 is responsible for the host range expansion of vAcRev, suggesting that Se-iap3 inhibits the progression of apoptosis initiated by viral infection and promotes viral propagation in hosts both permissive and non-permissive for AcMNPV and SeMNPV. PMID:27321273

  10. Gut immunity in Lepidopteran insects.

    PubMed

    Wu, Kai; Yang, Bing; Huang, Wuren; Dobens, Leonard; Song, Hongsheng; Ling, Erjun

    2016-11-01

    Lepidopteran insects constitute one of the largest fractions of animals on earth, but are considered pests in their relationship with man. Key to the success of this order of insects is its ability to digest food and absorb nutrition, which takes place in the midgut. Because environmental microorganisms can easily enter Lepidopteran guts during feeding, the innate immune response guards against pathogenic bacteria, virus and microsporidia that can be devoured with food. Gut immune responses are complicated by both resident gut microbiota and the surrounding peritrophic membrane and are distinct from immune responses in the body cavity, which depend on the function of the fat body and hemocytes. Due to their relevance to agricultural production, studies of Lepidopteran insect midgut and immunity are receiving more attention, and here we summarize gut structures and functions, and discuss how these confer immunity against different microorganisms. It is expected that increased knowledge of Lepidopteran gut immunity may be utilized for pest biological control in the future. PMID:26872544

  11. Phylogenetic signal in plant pathogen–host range

    PubMed Central

    Gilbert, Gregory S.; Webb, Campbell O.

    2007-01-01

    What determines which plant species are susceptible to a given plant pathogen is poorly understood. Experimental inoculations with fungal pathogens of plant leaves in a tropical rain forest show that most fungal pathogens are polyphagous but that most plant species in a local community are resistant to any given pathogen. The likelihood that a pathogen can infect two plant species decreases continuously with phylogenetic distance between the plants, even to ancient evolutionary distances. This phylogenetic signal in host range allows us to predict the likely host range of plant pathogens in a local community, providing an important tool for plant ecology, design of agronomic systems, quarantine regulations in international trade, and risk analysis of biological control agents. In particular, the results suggest that the rate of spread and ecological impacts of a disease through a natural plant community will depend strongly on the phylogenetic structure of the community itself and that current regulatory approaches strongly underestimate the local risks of global movement of plant pathogens or their hosts. PMID:17360396

  12. Host range, host ecology, and distribution of more than 11800 fish parasite species

    USGS Publications Warehouse

    Strona, Giovanni; Palomares, Maria Lourdes D.; Bailly, Nicholas; Galli, Paolo; Lafferty, Kevin D.

    2013-01-01

    Our data set includes 38 008 fish parasite records (for Acanthocephala, Cestoda, Monogenea, Nematoda, Trematoda) compiled from the scientific literature, Internet databases, and museum collections paired to the corresponding host ecological, biogeographical, and phylogenetic traits (maximum length, growth rate, life span, age at maturity, trophic level, habitat preference, geographical range size, taxonomy). The data focus on host features, because specific parasite traits are not consistently available across records. For this reason, the data set is intended as a flexible resource able to extend the principles of ecological niche modeling to the host–parasite system, providing researchers with the data to model parasite niches based on their distribution in host species and the associated host features. In this sense, the database offers a framework for testing general ecological, biogeographical, and phylogenetic hypotheses based on the identification of hosts as parasite habitat. Potential applications of the data set are, for example, the investigation of species–area relationships or the taxonomic distribution of host-specificity. The provided host–parasite list is that currently used by Fish Parasite Ecology Software Tool (FishPEST, http://purl.oclc.org/fishpest), which is a website that allows researchers to model several aspects of the relationships between fish parasites and their hosts. The database is intended for researchers who wish to have more freedom to analyze the database than currently possible with FishPEST. However, for readers who have not seen FishPEST, we recommend using this as a starting point for interacting with the database.

  13. Large Dynamic Range Simulations of Galaxies Hosting Supermassive Black Holes

    NASA Astrophysics Data System (ADS)

    Levine, Robyn

    2011-08-01

    The co-evolution of supermassive black holes (SMBHs) and their host galaxies is a rich problem, spanning a large-dynamic range and depending on many physical processes. Simulating the transport of gas and angular momentum from super-galactic scales all the way down to the outer edge of the black hole's accretion disk requires sophisticated numerical techniques with extensive treatment of baryonic physics. We use a hydrodynamic adaptive mesh refinement simulation to follow the growth and evolution of a typical disk galaxy hosting an SMBH, in a cosmological context (covering a dynamical range of 10 million!). We have adopted a piecemeal approach, focusing our attention on the gas dynamics in the central few hundred parsecs of the simulated galaxy (with boundary conditions provided by the larger cosmological simulation), and beginning with a simplified picture (no mergers or feedback). In this scenario, we find that the circumnuclear disk remains marginally stable against catastrophic fragmentation, allowing stochastic fueling of gas into the vicinity of the SMBH. I will discuss the successes and the limitations of these simulations, and their future direction.

  14. Ectomycorrhizal fungal richness declines towards the host species' range edge.

    PubMed

    Lankau, Richard A; Keymer, Daniel P

    2016-07-01

    Plant range boundaries are generally considered to reflect abiotic conditions; however, a rise in negative or decline in positive species interactions at range margins may contribute to these stable boundaries. While evidence suggests that pollinator mutualisms may decline near range boundaries, little is known about other important plant mutualisms, including microbial root symbionts. Here, we used molecular methods to characterize root-associated fungal communities in populations of two related temperate tree species from across the species' range in the eastern United States. We found that ectomycorrhizal fungal richness on plant roots declined with distance from the centre of the host species range. These patterns were not evident in nonmycorrhizal fungal communities on roots nor in fungal communities in bulk soil. Climatic and soil chemical variables could not explain these biogeographic patterns, although these abiotic gradients affected other components of the bulk soil and rhizosphere fungal community. Depauperate ectomycorrhizal fungal communities may represent an underappreciated challenge to marginal tree populations, especially as rapid climate change pushes these populations outside their current climate niche. PMID:27029467

  15. Combining experimental evolution and field population assays to study the evolution of host range breadth.

    PubMed

    Fellous, S; Angot, G; Orsucci, M; Migeon, A; Auger, P; Olivieri, I; Navajas, M

    2014-05-01

    Adapting to specific hosts often involves trade-offs that limit performance on other hosts. These constraints may either lead to narrow host ranges (i.e. specialists, able to exploit only one host type) or wide host ranges often leading to lower performance on each host (i.e. generalists). Here, we combined laboratory experiments on field populations with experimental evolution to investigate the impact of adaptation to the host on host range evolution and associated performance over this range. We used the two-spotted spider mite, Tetranychus urticae, a model organism for studies on the evolution of specialization. Field mite populations were sampled on three host plant species: tomato, citrus tree and rosebay (Nerium oleander). Testing these populations in the laboratory revealed that tomato populations of mites could exploit tomato only, citrus populations could exploit citrus and tomato whereas Nerium populations could exploit all three hosts. Besides, the wider niche ranges of citrus and Nerium populations came at the cost of low performance on their non-native hosts. Experimental lines selected to live on the same three host species exhibited similar patterns of host range and relative performance. This result suggests that adaptation to a new host species may lead to wider host ranges but at the expense of decreased performance on other hosts. We conclude that experimental evolution may reliably inform on evolution in the field. PMID:24689448

  16. Host range, prevalence, and genetic diversity of adenoviruses in bats.

    PubMed

    Li, Yan; Ge, Xingyi; Zhang, Huajun; Zhou, Peng; Zhu, Yan; Zhang, Yunzhi; Yuan, Junfa; Wang, Lin-Fa; Shi, Zhengli

    2010-04-01

    Bats are the second largest group of mammals on earth and act as reservoirs of many emerging viruses. In this study, a novel bat adenovirus (AdV) (BtAdV-TJM) was isolated from bat fecal samples by using a bat primary kidney cell line. Infection studies indicated that most animal and human cell lines are susceptible to BtAdV-TJM, suggesting a possible wide host range. Genome analysis revealed 30 putative genes encoding proteins homologous to their counterparts in most known AdVs. Phylogenetic analysis placed BtAdV-TJM within the genus Mastadenovirus, most closely related to tree shrew and canine AdVs. PCR analysis of 350 bat fecal samples, collected from 19 species in five Chinese provinces during 2007 and 2008, indicated that 28 (or 8%) samples were positive for AdVs. The samples were from five bat species, Hipposideros armiger, Myotis horsfieldii, M. ricketti, Myotis spp., and Scotophilus kuhlii. The prevalence ranged from 6.25% (H. armiger in 2007) to 40% (M. ricketti in 2007). Comparison studies based on available partial sequences of the pol gene demonstrated a great genetic diversity among bat AdVs infecting different bat species as well as those infecting the same bat species. This is the first report of a genetically diverse group of DNA viruses in bats. Our results support the notion, derived from previous studies based on RNA viruses (especially coronaviruses and astroviruses), that bats seem to have the unusual ability to harbor a large number of genetically diverse viruses within a geographic location and/or within a taxonomic group. PMID:20089640

  17. Factors affecting host range in a generalist seed pathogen of semi-arid shrublands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. In weed biocontrol, the potential impact of the biocontrol organism on non-target species is a major concern traditionally addressed with laboratory experiments that measure potential or maximum host range. Several factors may operate to reduce realized host range relative to potential host rang...

  18. Cucumis melo endornavirus: Genome organization, host range and co-divergence with the host.

    PubMed

    Sabanadzovic, Sead; Wintermantel, William M; Valverde, Rodrigo A; McCreight, James D; Aboughanem-Sabanadzovic, Nina

    2016-03-01

    A high molecular weight dsRNA was isolated from a Cucumis melo L. plant (referred to as 'CL01') of an unknown cultivar and completely sequenced. Sequence analyses showed that dsRNA is associated with an endornavirus for which a name Cucumis melo endornavirus (CmEV) is proposed. The genome of CmEV-CL01 consists of 15,078 nt, contains a single, 4939 codons-long ORF and terminates with a stretch of 10 cytosine residues. Comparisons of the putative CmEV-encoded polyprotein with available references in protein databases revealed a unique genome organization characterized by the presence of the following domains: viral helicase Superfamily 1 (Hel-1), three glucosyltransferases (doublet of putative capsular polysaccharide synthesis proteins and a putative C_28_Glycosyltransferase), and an RNA-dependent RNA polymerase (RdRp). The presence of three glycome-related domains of different origin makes the genome organization of CmEV unique among endornaviruses. Phylogenetic analyses of viral RdRp domains showed that CmEV belongs to a specific lineage within the family Endornaviridae made exclusively of plant-infecting endornaviruses. An RT-PCR based survey demonstrated high incidence of CmEV among melon germplasm accession (>87% of tested samples). Analyses of partial genome sequences of CmEV isolates from 26 different melon genotypes suggest fine-tuned virus adaptation and co-divergence with the host. Finally, results of the present study revealed that CmEV is present in plants belonging to three different genera in the family Cucurbitaceae. Such diverse host range is unreported for known endornaviruses and suggests a long history of CmEV association with cucurbits predating their speciation. PMID:26805037

  19. Molecular evolution of the odorant and gustatory receptor genes in lepidopteran insects: implications for their adaptation and speciation.

    PubMed

    Engsontia, Patamarerk; Sangket, Unitsa; Chotigeat, Wilaiwan; Satasook, Chutamas

    2014-08-01

    Lepidoptera (comprised of butterflies and moths) is one of the largest groups of insects, including more than 160,000 described species. Chemoreception plays important roles in the adaptation of these species to a wide range of niches, e.g., plant hosts, egg-laying sites, and mates. This study investigated the molecular evolution of the lepidopteran odorant (Or) and gustatory receptor (Gr) genes using recently identified genes from Bombyx mori, Danaus plexippus, Heliconius melpomene, Plutella xylostella, Heliothis virescens, Manduca sexta, Cydia pomonella, and Spodoptera littoralis. A limited number of cases of large lineage-specific gene expansion are observed (except in the P. xylostella lineage), possibly due to selection against tandem gene duplication. There has been strong purifying selection during the evolution of both lepidopteran odorant and gustatory genes, as shown by the low ω values estimated through CodeML analysis, ranging from 0.0093 to 0.3926. However, purifying selection has been relaxed on some amino acid sites in these receptors, leading to sequence divergence, which is a precursor of positive selection on these sequences. Signatures of positive selection were detected only in a few loci from the lineage-specific analysis. Estimation of gene gains and losses suggests that the common ancestor of the Lepidoptera had fewer Or genes compared to extant species and an even more reduced number of Gr genes, particularly within the bitter receptor clade. Multiple gene gains and a few gene losses occurred during the evolution of Lepidoptera. Gene family expansion may be associated with the adaptation of lepidopteran species to plant hosts, especially after angiosperm radiation. Phylogenetic analysis of the moth sex pheromone receptor genes suggested that chromosomal translocations have occurred several times. New sex pheromone receptors have arisen through tandem gene duplication. Positive selection was detected at some amino acid sites predicted to be

  20. Controls on pathogen species richness in plants’ introduced and native ranges: roles of residence time, range size and host traits

    PubMed Central

    Mitchell, Charles E; Blumenthal, Dana; Jarošík, Vojtěch; Puckett, Emily E; Pyšek, Petr

    2010-01-01

    Introduced species escape many pathogens and other enemies, raising three questions. How quickly do introduced hosts accumulate pathogen species? What factors control pathogen species richness? Are these factors the same in the hosts’ native and introduced ranges? We analysed fungal and viral pathogen species richness on 124 plant species in both their native European range and introduced North American range. Hosts introduced 400 years ago supported six times more pathogens than those introduced 40 years ago. In hosts’ native range, pathogen richness was greater on hosts occurring in more habitat types, with a history of agricultural use and adapted to greater resource supplies. In hosts’ introduced range, pathogen richness was correlated with host geographic range size, agricultural use and time since introduction, but not any measured biological traits. Introduced species have accumulated pathogens at rates that are slow relative to most ecological processes, and contingent on geographic and historic circumstance. PMID:20973907

  1. Endophytic Phomopsis species: host range and implications for diversity estimates.

    PubMed

    Murali, T S; Suryanarayanan, T S; Geeta, R

    2006-07-01

    Foliar endophyte assemblages of teak trees growing in dry deciduous and moist deciduous forests of Nilgiri Biosphere Reserve were compared. A species of Phomopsis dominated the endophyte assemblages of teak, irrespective of the location of the host trees. Internal transcribed spacer sequence analysis of 11 different Phomopsis isolates (ten from teak and one from Cassia fistula) showed that they fall into two groups, which are separated by a relatively long branch that is strongly supported. The results showed that this fungus is not host restricted and that it continues to survive as a saprotroph in teak leaf, possibly by exploiting senescent leaves as well as the litter. Although the endophyte assemblage of a teak tree growing about 500 km from the forests was also dominated by a Phomopsis sp., it separated into a different group based on internal transcribed spacer sequence analysis. Our results with an endophytic Phomopsis sp. reinforce the earlier conclusions reached by others for pathogenic Phomopsis sp., i.e., that this fungus is not host specific, and the species concept of Phomopsis needs to be redefined. PMID:16917524

  2. Controls on pathogen species richness in plants introduced and native ranges: roles of residence time, range size and host traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction of hosts to new geographic regions allows them to escape many pathogens, raising two questions. How quickly do introduced hosts accumulate pathogens? Do the same factors control pathogen accumulation as in the native range? We analyzed fungal and viral pathogen species richness on 124 p...

  3. Geographic host use variabiliy and host range evolutionary dynamics in the phytophagous insect Apagomerella versicolor (Cerambycidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The high diversity of phytophagous insects has been explained by the tendency of the group towards specialization; however, generalism may be advantageous in some environments. The cerambycid Apagomerella versicolor exhibits intraspecific geographical variation in host use. In northern Argentina it ...

  4. Contemporary evolution of host plant range expansion in an introduced herbivorous beetle Ophraella communa.

    PubMed

    Fukano, Y; Doi, H; Thomas, C E; Takata, M; Koyama, S; Satoh, T

    2016-04-01

    Host range expansion of herbivorous insects is a key event in ecological speciation and insect pest management. However, the mechanistic processes are relatively unknown because it is difficult to observe the ongoing host range expansion in natural population. In this study, we focused on the ongoing host range expansion in introduced populations of the ragweed leaf beetle, Ophraella communa, to estimate the evolutionary process of host plant range expansion of a herbivorous insect. In the native range of North America, O. communa does not utilize Ambrosia trifida, as a host plant, but this plant is extensively utilized in the beetle's introduced range. Larval performance and adult preference experiments demonstrated that native O. communa beetles show better survival on host plant individuals from introduced plant populations than those from native plant populations and they also oviposit on the introduced plant, but not on the native plant. Introduced O. communa beetles showed significantly higher performance on and preference for both introduced and native A. trifida plants, when compared with native O. communa. These results indicate the contemporary evolution of host plant range expansion of introduced O. communa and suggest that the evolutionary change of both the host plant and the herbivorous insect involved in the host range expansion. PMID:26728888

  5. Frequency and Fitness Consequences of Bacteriophage Φ6 Host Range Mutations

    PubMed Central

    Ford, Brian E.; Sun, Bruce; Carpino, James; Chapler, Elizabeth S.; Ching, Jane; Choi, Yoon; Jhun, Kevin; Kim, Jung D.; Lallos, Gregory G.; Morgenstern, Rachelle; Singh, Shalini; Theja, Sai; Dennehy, John J.

    2014-01-01

    Viruses readily mutate and gain the ability to infect novel hosts, but few data are available regarding the number of possible host range-expanding mutations allowing infection of any given novel host, and the fitness consequences of these mutations on original and novel hosts. To gain insight into the process of host range expansion, we isolated and sequenced 69 independent mutants of the dsRNA bacteriophage Φ6 able to infect the novel host, Pseudomonas pseudoalcaligenes. In total, we found at least 17 unique suites of mutations among these 69 mutants. We assayed fitness for 13 of 17 mutant genotypes on P. pseudoalcaligenes and the standard laboratory host, P. phaseolicola. Mutants exhibited significantly lower fitnesses on P. pseudoalcaligenes compared to P. phaseolicola. Furthermore, 12 of the 13 assayed mutants showed reduced fitness on P. phaseolicola compared to wildtype Φ6, confirming the prevalence of antagonistic pleiotropy during host range expansion. Further experiments revealed that the mechanistic basis of these fitness differences was likely variation in host attachment ability. In addition, using computational protein modeling, we show that host-range expanding mutations occurred in hotspots on the surface of the phage's host attachment protein opposite a putative hydrophobic anchoring domain. PMID:25409341

  6. Genetic, ecological and geographic covariables explaining host range and specificity of a microsporidian parasite.

    PubMed

    Lange, Benjamin; Kaufmann, Andrea Patricia; Ebert, Dieter

    2015-11-01

    Parasites often have a smaller geographic distribution than their hosts. Common garden infection trials can untangle the role that historical contingencies, ecological conditions and the genetic constitution of local host populations play in limiting parasite geographic range; however, infection trials usually overestimate the range of hosts in which a parasite could naturally persist. This study overcomes that problem by using multigeneration, long-term persistence experiments. We study the microsporidian parasite Hamiltosporidium tvaerminnensis in monoclonal populations of Daphnia magna from 43 widely spread sites. The parasite persisted well in hosts collected from its natural geographic range, but demonstrated long-term persistence in only a few host genotypes outside this range. Genetic distance between hosts from the parasite's origin site and newly tested host populations correlated negatively with parasite persistence. Furthermore, the parasite persisted only in host populations from habitats with a high likelihood of drying up in summer, although we excluded environmental variation in our experiments. Together, our results suggest that host genetic factors play the dominant role in explaining the limited geographic range of parasites and that these genetic differences covary with geographic distance and the habitat type the host is adapted to. PMID:26147623

  7. Cucurbit host range of Myrothecium roridum isolates from watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2010, a foliar and stem-lesion disease caused by Myrothecium roridum was observed for the first time in Oklahoma causing moderate to severe defoliation. The objective of this study was to compare the susceptibility of the vegetation and fruit of a broad range of commercially important cucurbits ...

  8. Host range of the inadvertent biological control agent Caloptilia triadicae: an invasive herbivore of Chinese tallowtree

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In its native range the invasive weed, Rhodomyrtus tomentosa is host to a suite of herbivores. One, Strepsicrates sp. (Lepidoptera: Tortricidae) was collected in China in 2014, introduced under quarantine in Florida, USA and tested against related species to determine its host range and suitability ...

  9. Host range of Caloptilia triadicae (Lepidoptera: Gracillariidae): an adventive herbivore of Chinese tallowtree (Malpighiales: Euphorbiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In its native range the invasive weed, Rhodomyrtus tomentosa is host to a suite of herbivores. One, Strepsicrates sp. (Lepidoptera: Tortricidae) was collected in China in 2014, introduced under quarantine in Florida, USA and tested against related species to determine its host range and suitability ...

  10. Inferring host range dynamics from comparative data: the protozoan parasites of new world monkeys.

    PubMed

    Waxman, David; Weinert, Lucy A; Welch, John J

    2014-07-01

    Uncovering the ecological determinants of parasite host range is a central goal of comparative parasitology and infectious disease ecology. But while parasites are often distributed nonrandomly across the host phylogeny, such patterns are difficult to interpret without a genealogy for the parasite samples and without knowing what sorts of ecological dynamics might lead to what sorts of nonrandomness. We investigated inferences from comparative data, using presence/absence records from protozoan parasites of the New World monkeys. We first demonstrate several distinct types of phylogenetic signal in these data, showing, for example, that parasite species are clustered on the host tree and that closely related host species harbor similar numbers of parasite species. We then show that all of these patterns can be generated by a single, simple dynamical model, in which parasite host range changes more rapidly than host speciation/extinction and parasites preferentially colonize uninfected host species that are closely related to their existing hosts. Fitting this model to data, we then estimate its parameters. Finally, we caution that quite different ecological processes can lead to similar signatures but show how phylogenetic variation in host susceptibility can be distinguished from a tendency for parasites to colonize closely related hosts. Our new process-based analyses, which estimate meaningful parameters, should be useful for inferring the determinants of parasite host range and transmission success. PMID:24921601

  11. Biogeographic Variation in Host Range Phenotypes and Taxonomic Composition of Marine Cyanophage Isolates

    PubMed Central

    Hanson, China A.; Marston, Marcia F.; Martiny, Jennifer B. H.

    2016-01-01

    Despite the important role of phages in marine systems, little is understood about how their diversity is distributed in space. Biogeographic patterns of marine phages may be difficult to detect due to their vast genetic diversity, which may not be accurately represented by conserved marker genes. To investigate the spatial biogeographic structure of marine phages, we isolated over 400 cyanophages on Synechococcus host strain WH7803 at three coastal locations in the United States (Rhode Island, Washington, and southern California). Approximately 90% of the cyanophage isolates were myoviruses, while the other 10% were podoviruses. The diversity of isolates was further characterized in two ways: (i) taxonomically, using conserved marker genes and (ii) phenotypically, by testing isolates for their ability to infect a suite of hosts, or their “host range.” Because host range is a highly variable trait even among closely related isolates, we hypothesized that host range phenotypes of cyanophage isolates would vary more strongly among locations than would taxonomic composition. Instead, we found evidence for strong biogeographic variation both in taxonomic composition and host range phenotypes, with little taxonomic overlap among the three coastal regions. For both taxonomic composition and host range phenotypes, cyanophage communities from California and Rhode Island were the most dissimilar, while Washington communities exhibited similarity to each of the other two locations. These results suggest that selection imposed by spatial variation in host dynamics influence the biogeographic distribution of cyanophages. PMID:27446023

  12. Identification of olfactory receptor neurons in Uraba lugens (Lepidoptera: Nolidae) and its implications for host range.

    PubMed

    Park, Kye Chung; Withers, Toni M; Suckling, David Maxwell

    2015-07-01

    Phytophagous insects detect volatile compounds produced by host and non-host plants, using species-specific sets of olfactory receptor neurons (ORNs). To investigate the relationship between the range of host plants and the profile of ORNs, single sensillum recordings were carried out to identify ORNs and corresponding active compounds in female Uraba lugens (Lepidoptera: Nolidae), an oligophagous eucalypt feeder. Based on the response profiles to 39 plant volatile compounds, 13 classes of sensilla containing 40 classes of ORNs were identified in female U. lugens. More than 95% (163 out of 171) of these sensilla contained 16 classes of ORNs with narrow response spectra, and 62.6% (107 out of 171) 18 classes of ORNs with broad response spectra. Among the specialized ORNs, seven classes of ORNs exhibited high specificity to 1,8-cineole, (±)-citronellal, myrcene, (±)-linalool and (E)-β-caryophyllene, major volatiles produced by eucalypts, while nine other classes of ORNs showed highly specialized responses to green leaf volatiles, germacrene D, (E)-β-farnesene and geranyl acetate that are not produced by most eucalypts. We hypothesize that female U. lugens can recognize their host plants by detecting key host volatile compounds, using a set of ORNs tuned to host volatiles, and discriminate them from non-host plants using another set of ORNs specialized for non-host volatiles. The ORNs with broad response spectra may enhance the discrimination between host and non-host plants by adding moderately selective sensitivity. Based on our finding, it is suggested that phytophagous insects use the combinational input from both host-specific and non-host specific ORNs for locating their host plants, and the electrophysiological characterization of ORN profiles would be useful in predicting the range of host plants in phytophagous insects. PMID:25937382

  13. Host Range Expansion of Honey Bee Black Queen Cell Virus in the Bumble Bee, Bombus huntii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honey bee viruses display a host range that is not restricted to their original host, European honey bees, Apis mellifera. Here we provide the first evidence that Black Queen Cell Virus (BQCV), one of the most prevalent honey bee viruses, can cause an infection in both laboratory-reared and field-co...

  14. Host plant range of Raoiella indica (Acari: Tenuipalpidae) in areas of invasion of the New World.

    PubMed

    Carrillo, Daniel; Amalin, Divina; Hosein, Farzan; Roda, Amy; Duncan, Rita E; Peña, Jorge E

    2012-08-01

    Raoiella indica has spread rapidly through the Neotropical region where the mite damages economically and ecologically important plants. Three studies were conducted to determine the host plant range of R. indica, using the presence of colonies containing all life stages as an indicator of reproductive suitability. Periodic surveys at the Fairchild Tropical Botanic Garden (Miami Dade County, FL, USA) and the Royal Botanical Gardens (Port of Spain, Trinidad and Tobago) identified 27 new reproductive host plants. The reproductive suitability of two dicotyledonous species and three native Florida palm species was examined. An updated list of reproductive host plants of R. indica is presented. All reported reproductive hosts (91 plant species) of R. indica are monocots from the orders Arecales (Arecaceae), Zingiberales (Heliconiaceae, Musaceae, Strelitziaceae, Zingiberaceae) and Pandanales (Pandanaceae). Most are palms of the family Arecaceae that originated in areas of the Eastern Hemisphere; about one fourth of the reported hosts are native to the New World and could be considered new host associations of R. indica. Six years after the initial detection in the Caribbean, R. indica has expanded its host plant range. Here we report 27 new reproductive host of R. indica that represent 30% of increase on previous host plant records. As this mite continues spreading in the Neotropical region a great diversity of plants is potentially affected. PMID:21915682

  15. Experimental adaptation of Burkholderia cenocepacia to onion medium reduces host range.

    PubMed

    Ellis, Crystal N; Cooper, Vaughn S

    2010-04-01

    It is unclear whether adaptation to a new host typically broadens or compromises host range, yet the answer bears on the fate of emergent pathogens and symbionts. We investigated this dynamic using a soil isolate of Burkholderia cenocepacia, a species that normally inhabits the rhizosphere, is related to the onion pathogen B. cepacia, and can infect the lungs of cystic fibrosis patients. We hypothesized that adaptation of B. cenocepacia to a novel host would compromise fitness and virulence in alternative hosts. We modeled adaptation to a specific host by experimentally evolving 12 populations of B. cenocepacia in liquid medium composed of macerated onion tissue for 1,000 generations. The mean fitness of all populations increased by 78% relative to the ancestor, but significant variation among lines was observed. Populations also varied in several phenotypes related to host association, including motility, biofilm formation, and quorum-sensing function. Together, these results suggest that each population adapted by fixing different sets of adaptive mutations. However, this adaptation was consistently accompanied by a loss of pathogenicity to the nematode Caenorhabditis elegans; by 500 generations most populations became unable to kill nematodes. In conclusion, we observed a narrowing of host range as a consequence of prolonged adaptation to an environment simulating a specific host, and we suggest that emergent pathogens may face similar consequences if they become host-restricted. PMID:20154121

  16. Narrow- and Broad-Host-Range Symbiotic Plasmids of Rhizobium spp. Strains That Nodulate Phaseolus vulgaris

    PubMed Central

    Brom, Susana; Martinez, Esperanza; Dávila, Guillermo; Palacios, Rafael

    1988-01-01

    Agrobacterium transconjugants containing symbiotic plasmids from different Rhizobium spp. strains that nodulate Phaseolus vulgaris were obtained. All transconjugants conserved the parental nodulation host range. Symbiotic (Sym) plasmids of Rhizobium strains isolated originally from P. vulgaris nodules, which had a broad nodulation host range, and single-copy nitrogenase genes conferred a Fix+ phenotype to the Agrobacterium transconjugants. A Fix− phenotype was obtained with Sym plasmids of strains isolated from P. vulgaris nodules that had a narrow host range and reiterated nif genes, as well as with Sym plasmids of strains isolated from other legumes that presented single nif genes and a broad nodulation host range. This indicates that different types of Sym plasmids can confer the ability to establish an effective symbiosis with P. vulgaris. Images PMID:16347637

  17. Coupled range dynamics of brood parasites and their hosts responding to climate and vegetation changes.

    PubMed

    Péron, Guillaume; Altwegg, Res; Jamie, Gabriel A; Spottiswoode, Claire N

    2016-09-01

    As populations shift their ranges in response to global change, local species assemblages can change, setting the stage for new ecological interactions, community equilibria and evolutionary responses. Here, we focus on the range dynamics of four avian brood parasite species and their hosts in southern Africa, in a context of bush encroachment (increase in woody vegetation density in places previously occupied by savanna-grassland mosaics) favouring some species at the expense of others. We first tested whether hosts and parasites constrained each other's ability to expand or maintain their ranges. Secondly, we investigated whether range shifts represented an opportunity for new host-parasite and parasite-parasite interactions. We used multispecies dynamic occupancy models with interactions, fitted to citizen science data, to estimate the contribution of interspecific interactions to range shifts and to quantify the change in species co-occurrence probability over a 25-year period. Parasites were able to track their hosts' range shifts. We detected no deleterious effect of the parasites' presence on either the local population viability of host species or the hosts' ability to colonize newly suitable areas. In the recently diversified indigobird radiation (Vidua spp.), following bush encroachment, the new assemblages presented more potential opportunities for speciation via host switch, but also more potential for hybridization between extant lineages, also via host switch. Multispecies dynamic occupancy models with interactions brought new insights into the feedbacks between range shifts, biotic interactions and local demography: brood parasitism had little detected impact on extinction or colonization processes, but inversely the latter processes affected biotic interactions via the modification of co-occurrence patterns. PMID:27155344

  18. Host range of rice yellow mottle virus in Sudano-Sahelian Savannahs.

    PubMed

    Allarangaye, M D; Traoré, O; Traoré, E V S; Millogo, R J; Guinko, S; Konaté, G

    2007-05-01

    In the present study, we investigated on the experimental host range of RYMV among plant species most of which are frequently encountered in rice-growing environments of west and central African savannahs. Only seven out of 66 plant species inoculated were infected by RYMV. All susceptible plant species belonged to the Poaceae family and three of them (Chloris prieuri, Eragrostis cilianensis and Shoenefeldia gracilis) were reported for the first time. Symptoms were conspicuous and persistent in most species but disappeared totally in older plants of some host species such as S. gracilis and Eragrostis tenella. Therefore, surveys for identification ofRYMV wild hosts should be conducted before the flowering stage. Virus-host Interactions were studied between 15 RYMV isolates of different strains and 10 wild host species. Differential reactions were obtained in the crow-foot grass Dactyloctenium aegyptium which was susceptible to five of the fifteen isolates. All other plants were susceptible to the whole set of virus isolates. Altogether, this study underlined the narrowness of RYMV host range and pointed out the complexity of interactions between the virus and its hosts, especially the rationale behind overcoming host barriers. PMID:19069951

  19. Evolutionary Paths That Expand Plasmid Host-Range: Implications for Spread of Antibiotic Resistance.

    PubMed

    Loftie-Eaton, Wesley; Yano, Hirokazu; Burleigh, Stephen; Simmons, Ryan S; Hughes, Julie M; Rogers, Linda M; Hunter, Samuel S; Settles, Matthew L; Forney, Larry J; Ponciano, José M; Top, Eva M

    2016-04-01

    The World Health Organization has declared the emergence of antibiotic resistance to be a global threat to human health. Broad-host-range plasmids have a key role in causing this health crisis because they transfer multiple resistance genes to a wide range of bacteria. To limit the spread of antibiotic resistance, we need to gain insight into the mechanisms by which the host range of plasmids evolves. Although initially unstable plasmids have been shown to improve their persistence through evolution of the plasmid, the host, or both, the means by which this occurs are poorly understood. Here, we sought to identify the underlying genetic basis of expanded plasmid host-range and increased persistence of an antibiotic resistance plasmid using a combined experimental-modeling approach that included whole-genome resequencing, molecular genetics and a plasmid population dynamics model. In nine of the ten previously evolved clones, changes in host and plasmid each slightly improved plasmid persistence, but their combination resulted in a much larger improvement, which indicated positive epistasis. The only genetic change in the plasmid was the acquisition of a transposable element from a plasmid native to the Pseudomonas host used in these studies. The analysis of genetic deletions showed that the critical genes on this transposon encode a putative toxin-antitoxin (TA) and a cointegrate resolution system. As evolved plasmids were able to persist longer in multiple naïve hosts, acquisition of this transposon also expanded the plasmid's host range, which has important implications for the spread of antibiotic resistance. PMID:26668183

  20. Host-range Characterization of Two Pratylenchus coffeae Isolates from Brazil

    PubMed Central

    Silva, R. A.; Inomoto, M. M.

    2002-01-01

    Two isolates of Pratylenchus coffeae were collected from coffee roots (in Marília, São Paulo State, Brazil) and Aglaonema (in Rio de Janeiro City, Rio de Janeiro State, Brazil) and maintained in the laboratory on alfalfa callus. Twenty-four plants were tested in the greenhouse to characterize the host preference of these isolates. The host ranges of the isolates differed from each other and, interestingly, coffee, banana, and citrus were not among the better hosts of either isolate. Rather, sorghum, maize, rice, millet, okra, melon, eggplant, and lettuce were the best hosts of the Marília isolate. Poor hosts included French marigold, Rangpur lime, banana, sesame, peanut, sunflower, cotton, French bean, onion, and small onion. The best hosts of the Rio de Janeiro isolate were sesame, soybean, sorghum, castor oil plant, watermelon, squash, eggplant, and melon; the poorest hosts were French marigold, coffee, Rangpur lime, banana, sunflower, peanut, maize, millet, French bean, cotton, onion, sweet pepper, lettuce, okra, and small onion. These isolates have important molecular and morphological differences, suggesting host preference is linked to these characteristics. PMID:19265921

  1. Structural basis for antagonizing a host restriction factor by C7 family of poxvirus host-range proteins

    PubMed Central

    Meng, Xiangzhi; Krumm, Brian; Li, Yongchao; Deng, Junpeng; Xiang, Yan

    2015-01-01

    Human sterile alpha motif domain-containing 9 (SAMD9) protein is a host restriction factor for poxviruses, but it can be overcome by some poxvirus host-range proteins that share homology with vaccinia virus C7 protein. To understand the mechanism of action for this important family of host-range factors, we determined the crystal structures of C7 and myxoma virus M64, a C7 family member that is unable to antagonize SAMD9. Despite their different functions and only 23% sequence identity, the two proteins have very similar overall structures, displaying a previously unidentified fold comprised of a compact 12-stranded antiparallel β-sandwich wrapped in two short α helices. Extensive structure-guided mutagenesis of C7 identified three loops clustered on one edge of the β sandwich as critical for viral replication and binding with SAMD9. The loops are characterized with functionally important negatively charged, positively charged, and hydrophobic residues, respectively, together forming a unique “three-fingered molecular claw.” The key residues of the claw are not conserved in two C7 family members that do not antagonize SAMD9 but are conserved in distantly related C7 family members from four poxvirus genera that infect diverse mammalian species. Indeed, we found that all in the latter group of proteins bind SAMD9. Taken together, our data indicate that diverse mammalian poxviruses use a conserved molecular claw in a C7-like protein to target SAMD9 and overcome host restriction. PMID:26578811

  2. Identification of FAM111A as an SV40 Host Range Restriction and Adenovirus Helper Factor

    PubMed Central

    Padi, Megha; Korkhin, Anna; James, Robert L.; Adelmant, Guillaume; Yoon, Rosa; Guo, Luxuan; Berrios, Christian; Zhang, Ying; Calderwood, Michael A.; Velmurgan, Soundarapandian; Cheng, Jingwei; Marto, Jarrod A.; Hill, David E.; Cusick, Michael E.; Vidal, Marc; Florens, Laurence; Washburn, Michael P.; Litovchick, Larisa; DeCaprio, James A.

    2012-01-01

    The small genome of polyomaviruses encodes a limited number of proteins that are highly dependent on interactions with host cell proteins for efficient viral replication. The SV40 large T antigen (LT) contains several discrete functional domains including the LXCXE or RB-binding motif, the DNA binding and helicase domains that contribute to the viral life cycle. In addition, the LT C-terminal region contains the host range and adenovirus helper functions required for lytic infection in certain restrictive cell types. To understand how LT affects the host cell to facilitate viral replication, we expressed full-length or functional domains of LT in cells, identified interacting host proteins and carried out expression profiling. LT perturbed the expression of p53 target genes and subsets of cell-cycle dependent genes regulated by the DREAM and the B-Myb-MuvB complexes. Affinity purification of LT followed by mass spectrometry revealed a specific interaction between the LT C-terminal region and FAM111A, a previously uncharacterized protein. Depletion of FAM111A recapitulated the effects of heterologous expression of the LT C-terminal region, including increased viral gene expression and lytic infection of SV40 host range mutants and adenovirus replication in restrictive cells. FAM111A functions as a host range restriction factor that is specifically targeted by SV40 LT. PMID:23093934

  3. Identification of FAM111A as an SV40 host range restriction and adenovirus helper factor.

    PubMed

    Fine, Debrah A; Rozenblatt-Rosen, Orit; Padi, Megha; Korkhin, Anna; James, Robert L; Adelmant, Guillaume; Yoon, Rosa; Guo, Luxuan; Berrios, Christian; Zhang, Ying; Calderwood, Michael A; Velmurgan, Soundarapandian; Cheng, Jingwei; Marto, Jarrod A; Hill, David E; Cusick, Michael E; Vidal, Marc; Florens, Laurence; Washburn, Michael P; Litovchick, Larisa; DeCaprio, James A

    2012-01-01

    The small genome of polyomaviruses encodes a limited number of proteins that are highly dependent on interactions with host cell proteins for efficient viral replication. The SV40 large T antigen (LT) contains several discrete functional domains including the LXCXE or RB-binding motif, the DNA binding and helicase domains that contribute to the viral life cycle. In addition, the LT C-terminal region contains the host range and adenovirus helper functions required for lytic infection in certain restrictive cell types. To understand how LT affects the host cell to facilitate viral replication, we expressed full-length or functional domains of LT in cells, identified interacting host proteins and carried out expression profiling. LT perturbed the expression of p53 target genes and subsets of cell-cycle dependent genes regulated by the DREAM and the B-Myb-MuvB complexes. Affinity purification of LT followed by mass spectrometry revealed a specific interaction between the LT C-terminal region and FAM111A, a previously uncharacterized protein. Depletion of FAM111A recapitulated the effects of heterologous expression of the LT C-terminal region, including increased viral gene expression and lytic infection of SV40 host range mutants and adenovirus replication in restrictive cells. FAM111A functions as a host range restriction factor that is specifically targeted by SV40 LT. PMID:23093934

  4. Comparison of field-collected ascovirus isolates by DNA hybridization, host range, and histopathology.

    PubMed

    Hamm, J J; Styer, E L; Federici, B A

    1998-09-01

    Six field-collected ascovirus isolates obtained from five noctuid species in the continental United States were compared with respect to the general relatedness of their DNA, host range, and histopathology. Two isolates were from Spodoptera frugiperda, and the other four were from Autographa precationis, Heliothis virescens, Helicoverpa zea, and Trichoplusia ni. DNA-DNA hybridization studies showed that the six isolates belonged to three distinct viral species, with the isolates from S. frugiperda composing one species, those from A. precationis and H. virescens a second species, and those from H. zea and T. ni a third species. The host range and histopathology of each isolate was studied in eight noctuid species, S. frugiperda, Spodoptera ornithogalli, Spodoptera exigua, Spodoptera eridania, H. virescens, H. zea, A. precationis, and Feltia subterranea. Though some variation existed between the different isolates of each viral species, distinct patterns were apparent for each. The viral species from S. frugiperda had a host range that was limited primarily to Spodoptera species and both isolates of this virus only replicated and caused significant pathology in the fat body, whereas the viral species from A. precationis and H. virescens had a much broader host range that included most of the species tested, but also had a tissue tropism primarily restricted to the fat body. The viral species from T. ni and H. zea readily infected all the hosts tested, where the principal site of replication and significant pathology was the epidermis. In many test hosts, however, this viral species also replicated and caused significant pathology in the tracheal epithelium and to a lesser extent in the fat body. Aside from contributing to knowledge of ascovirus biology, these studies indicate that DNA hybridization profiles combined with studies of host range and tissue tropism can be used as characters for defining ascovirus species. PMID:9709014

  5. Host range conferred by the virulence-specifying plasmid of Agrobacterium tumefaciens.

    PubMed Central

    Loper, J E; Kado, C I

    1979-01-01

    The host range of Agrobacterium tumefaciens 1D1109, known to induce crown gall only on grapevine (Vitis spp.), was extended to include many plant species by transferring a tumor-inducing plasmid (pTi) from strain 1D1, a broad-host-range pathogen. The pTi plasmid was mobilized by the conjugative plasmid pRK2, which was inserted into 1D1 by mating with Escherichia coli J53(pRK2). The resulting transconjugants were screened for their ability to induce crown gall tumors on hosts other than grapevine by inoculation into sunflower. Transconjugants that were virulent on sunflower were then tested on 36 different host plants and compared with host-limited strain 1D1109 and the donor strain. Two transconjugants induced tumors on the same 28 plant species as those of the original plasmid donor 1D1(pRK2) (pTi). These results show that pRK2 promoted transfer of the pTi plasmid and suggest that the pTi plasmid rather than the A. tumefaciens chromosome determined the host range of the pathogen. Insertion of pRK2 alone did not extend the host range of strain 1D1109. Insertion of pS-a into A. tumefaciens 1D1 by mating with E. coli J53-1 (pS-a) resulted in the concomitant loss of pTi and virulence. There appears to be incompatibility between pTi and pS-a. Images PMID:457613

  6. Investigations of the Host Range of the Corn Cyst Nematode, Heterodera zeae, from Maryland

    PubMed Central

    Ringer, Chloe E.; Sardanelli, Sandra; Krusberg, Lorin R.

    1987-01-01

    The host range of the corn cyst nematode, Heterodera zeae, recently detected in Maryland, was investigated. A total of 269 plant entries, representing 68 families, 172 genera, and 204 species, was inoculated with cysts or a mixture of eggs and second-stage juveniles of H. zeae. The host range of the Maryland population of H. zeae was limited to plants of the Gramineae and included 11 tribes, 33 genera, 42 species, and 77 entries. All 22 corn (Zea mays) cultivars tested were hosts. Other economic hosts included certain cultivars of barley (Hordeum vulgare), oat (Arena sativa), rice (Oryza sativa), sorghum (Sorghum bicolor), sugar cane (Saccharum interspecific hybrid), and wheat (Triticum aestivum). Fall panicum (Panicum dichotomiflorum), a weed species common to cultivated fields in Maryland, was also a host for H. zeae. Other hosts included meadow foxtail (Alopecurus pratensis), Calamagrostis eipgeios, Job's tears (Coix Lachryma-Jobi), green sprangletop (Leptochloa dubia), witchgrass (Panicum capillare), broomcorn (Panicum miliaceum), fountain grass (Pennisetum rueppeli), reed canary grass (Phalaris arundinacea), common reed (Phragmites australis), eastern gamagrass (Tripsacum dactyloides), corn (Zea mays), and teosinte (Zea mexicana). PMID:19290286

  7. Genome organization and host range of a Brazilian isolate of johnsongrass mosaic virus.

    PubMed

    Camelo-García, Viviana Marcela; da Silva Andrade, Sónia Cristina; Geering, Andrew D W; Kitajima, Elliot Watanabe; Rezende, Jorge A M

    2016-05-01

    This work reports the complete genome sequence, production of a polyclonal antiserum, and host range of a Brazilian strain of johnsongrass mosaic virus (JGMV) found infecting Panicum maximum in the state of São Paulo, Brazil. The complete genome sequence of this potyvirus, comprising 9874 nucleotides, showed 82 % amino acid sequence identity in the polyprotein to that of an isolate of JGMV from Australia. The experimental host range of this virus included mainly fodder species. Cultivated species such as rice, oats, sugarcane, rye, corn and wheat were not infected, suggesting that current isolates of this potyvirus do not represent a threat to these crops in Brazil. PMID:26869279

  8. Biocontrol potential of Steinernema thermophilum and its symbiont Xenorhabdus indica against lepidopteran pests: virulence to egg and larval stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under laboratory conditions, the biocontrol potential of Steinernema thermophilum was tested against eggs and larval stages of two important lepidopteran insect pests, Helicoverpa armigera and Spodoptera litura (polyphagous pests), as well as Galleria mellonella (used as a model host) . In terms of ...

  9. Diverse wild bird host range of Mycoplasma gallisepticum in eastern North America.

    PubMed

    Dhondt, André A; DeCoste, Jonathan C; Ley, David H; Hochachka, Wesley M

    2014-01-01

    Emerging infectious diseases often result from pathogens jumping to novel hosts. Identifying possibilities and constraints on host transfer is therefore an important facet of research in disease ecology. Host transfers can be studied for the bacterium Mycoplasma gallisepticum, predominantly a pathogen of poultry until its 1994 appearance and subsequent epidemic spread in a wild songbird, the house finch Haemorhous mexicanus and some other wild birds. We screened a broad range of potential host species for evidence of infection by M. gallisepticum in order to answer 3 questions: (1) is there a host phylogenetic constraint on the likelihood of host infection (house finches compared to other bird species); (2) does opportunity for close proximity (visiting bird feeders) increase the likelihood of a potential host being infected; and (3) is there seasonal variation in opportunity for host jumping (winter resident versus summer resident species). We tested for pathogen exposure both by using PCR to test for the presence of M. gallisepticum DNA and by rapid plate agglutination to test for the presence of antibodies. We examined 1,941 individual birds of 53 species from 19 avian families. In 27 species (15 families) there was evidence for exposure with M. gallisepticum although conjunctivitis was very rare in non-finches. There was no difference in detection rate between summer and winter residents, nor between feeder birds and species that do not come to feeders. Evidence of M. gallisepticum infection was found in all species for which at least 20 individuals had been sampled. Combining the present results with those of previous studies shows that a diverse range of wild bird species may carry or have been exposed to M. gallisepticum in the USA as well as in Europe and Asia. PMID:25061684

  10. Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts

    PubMed Central

    Ferreira, Luciana de Lima; Pereira, Marcos Horácio; Guarneri, Alessandra Aparecida

    2015-01-01

    Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts. PMID:26469403

  11. Whole-Genome Sequencing of 10 Pseudomonas syringae Strains Representing Different Host Range Spectra

    PubMed Central

    Bartoli, Claudia; Carrere, Sébastien; Lamichhane, Jay Ram; Varvaro, Leonardo

    2015-01-01

    Pseudomonas syringae is a ubiquitous bacterium that readily persists in environmental habitats as a saprophyte and also is responsible for numerous diseases of crops. Here, we report the whole-genome sequences of 10 strains isolated from both woody and herbaceous plants that will contribute to the elucidation of the determinants of their host ranges. PMID:25931602

  12. Complete genome sequence of the broad-host-range strain Sinorhizobium fredii USDA257

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we announce the complete genome sequence of the symbiotic and nitrogen fixing bacterium Sinorhizobium fredii USDA257. The genome shares a high degree of similarity with the closely related broad-host-range strains S. fredii NGR234 and HH103. Most striking, the USDA257 genome encodes for a wealt...

  13. Oxatub[4]arene: a molecular "transformer" capable of hosting a wide range of organic cations.

    PubMed

    Jia, Fei; Wang, Hao-Yi; Li, Dong-Hao; Yang, Liu-Pan; Jiang, Wei

    2016-04-14

    The molecular "transformer", oxatub[4]arene, was found to be able to host a wide range of organic cations. The strong binding ability is believed to originate from its four interconvertible and deep-cavity conformers. The binding behavior of such adaptable receptors may provide implications for molecular recognition in nature. PMID:26955919

  14. The virA promoter is a host-range determinant in Agrobacterium tumefaciens.

    PubMed

    Turk, S C; Nester, E W; Hooykaas, P J

    1993-03-01

    The limited host range (LHR) Agrobacterium tumefaciens strain Ag162 is an isolate with a narrow host range. Introduction of the wide host range (WHR) virA gene is essential for extending the host range to Kalanchoë daigremontiana. In this report we show that the region upstream of the ATG start codon is responsible for the LHR phenomenon and that this is probably due to the non-inducibility of the LHRvirA promoter. By comparing the characteristics of the LHR and WHR VirA receptor proteins, it was found that the LHR VirA protein is able to activate the WHR VirG protein in the presence of acetosyringone and that this acetosyringone-dependent vir-induction is enhanced by the presence of D-glucose, as in the case of WHR VirA proteins. These results indicate that the domains, acting as receptors for sugars and phenolic signals, must be conserved between the LHR and WHR VirA receptor proteins. PMID:8469115

  15. Finalizing host range determination of a weed biological control pathogen with BLUPs and damage assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Colletotrichum gloeosporioides f. sp. salsolae (Penz.) Penz. & Sacc. in Penz. (CGS) is a facultative parasitic fungus being evaluated as a classical biological control agent of Russian thistle or tumbleweed (Salsola tragus L.). In initial host range determination tests, Henderson’s mixed model equat...

  16. Evolution of specialization: a phylogenetic study of host range in the red milkweed beetle (Tetraopes tetraophthalmus).

    PubMed

    Rasmann, Sergio; Agrawal, Anurag A

    2011-06-01

    Specialization is common in most lineages of insect herbivores, one of the most diverse groups of organisms on earth. To address how and why specialization is maintained over evolutionary time, we hypothesized that plant defense and other ecological attributes of potential host plants would predict the performance of a specialist root-feeding herbivore (the red milkweed beetle, Tetraopes tetraophthalmus). Using a comparative phylogenetic and functional trait approach, we assessed the determinants of insect host range across 18 species of Asclepias. Larval survivorship decreased with increasing phylogenetic distance from the true host, Asclepias syriaca, suggesting that adaptation to plant traits drives specialization. Among several root traits measured, only cardenolides (toxic defense chemicals) correlated with larval survival, and cardenolides also explained the phylogenetic distance effect in phylogenetically controlled multiple regression analyses. Additionally, milkweed species having a known association with other Tetraopes beetles were better hosts than species lacking Tetraopes herbivores, and milkweeds with specific leaf area values (a trait related to leaf function and habitat affiliation) similar to those of A. syriaca were better hosts than species having divergent values. We thus conclude that phylogenetic distance is an integrated measure of phenotypic and ecological attributes of Asclepias species, especially defensive cardenolides, which can be used to explain specialization and constraints on host shifts over evolutionary time. PMID:21597250

  17. Do-or-die life cycles and diverse post-infection resistance mechanisms limit the evolution of parasite host ranges.

    PubMed

    Sieber, Michael; Gudelj, Ivana

    2014-04-01

    In light of the dynamic nature of parasite host ranges and documented potential for rapid host shifts, the observed high host specificity of most parasites remains an ecological paradox. Different variants of host-use trade-offs have become a mainstay of theoretical explanations of the prevalence of host specialism, but empirical evidence for such trade-offs is rare. We propose an alternative theory based on basic features of the parasite life cycle: host selection and subsequent intrahost replication. We introduce a new concept of effective burst size that accounts for the fact that successful host selection does not guarantee intrahost replication. Our theory makes a general prediction that a parasite will expand its host range if its effective burst size is positive. An in silico model of bacteria-phage coevolution verifies our predictions and demonstrates that the tendency for relatively narrow host ranges in parasites can be explained even in the absence of trade-offs. PMID:24495077

  18. Host Range and Selectivity of the Hemiparasitic Plant Thesium chinense (Santalaceae)

    PubMed Central

    Suetsugu, Kenji; Kawakita, Atsushi; Kato, Makoto

    2008-01-01

    Background and Aims Thesium chinense is a hemiparasitic plant that is common in grassland habitats of eastern Asia. Although the physiology of Thesium has been well studied in attempts to control its weedy habit, there have been few ecological investigations of its parasitic life history. Thesium chinense is thought to parasitize species of Poaceae, but evidence remains circumstantial. Methods A vegetation survey was conducted to test whether any plant species occurs significantly more often in plots with T. chinense than expected. In addition, haustorial connections were examined directly by excavating the roots and post-attachment host selectivity was evaluated by comparing the observed numbers of haustoria on different hosts against those expected according to the relative below-ground biomass. Haustorium sizes were also compared among host species. Key Results Only two of the 38 species recorded, Lespedeza juncea and Eragrostis curvula, occurred more often in plots with Thesium than expected. In contrast to this, T. chinense parasitized 22 plant species in 11 families, corresponding to 57·9 % of plant species found at the study site. Haustoria were non-randomly distributed among host species, suggesting that there is some post-attachment host selectivity. Thesium chinense generally preferred the Poaceae, although haustoria formed on the Fabaceae were larger than those on other hosts. Conclusions This is the first quantitative investigation of the host range and selectivity of hemiparasitic plants of the Santalales. The preference for Fabaceae as hosts may be linked to the greater nutrient availability in these nitrogen-fixing plants. PMID:18492736

  19. Revised Host Range and Studies on the Life Cycle of Longidorus africanus

    PubMed Central

    Kolodge, Craig; Radewald, John D.; Shibuya, Fujio

    1987-01-01

    The host range of Longidorus africanus was demonstrated to be much wider than previously reported. All commercial crop plants tested, except two of four crucifers, were hosts of L. africanus. The nematode was widespread in fields, and soil type did not appear to be related to its distribution. The minimum time to complete a life cycle was 9 weeks at 28 C in a plant growth chamber. Field observations of population densities indicated, however, that in undisturbed field soils the life cycle required considerably less time than was indicated by growth chamber studies. PMID:19290109

  20. Construction of the recombinant broad-host-range plasmids providing their bacterial hosts arsenic resistance and arsenite oxidation ability.

    PubMed

    Drewniak, Lukasz; Ciezkowska, Martyna; Radlinska, Monika; Sklodowska, Aleksandra

    2015-02-20

    The plasmid pSinA of Sinorhizobium sp. M14 was used as a source of functional phenotypic modules, encoding proteins involved in arsenite oxidation and arsenic resistance, to obtain recombinant broad-host-range plasmids providing their bacterial hosts arsenic resistance and arsenite oxidative ability. An arsenite oxidation module was cloned into pBBR1MCS-2 vector yielding plasmid vector pAIO1, while an arsenic resistance module was cloned into pCM62 vector yielding plasmid pARS1. Both plasmid constructs were introduced (separately and together) into the cells of phylogenetically distant (representing Alpha-, Beta-, and Gammaproteobacteria) and physiologically diversified (unable to oxidize arsenite and susceptible/resistant to arsenite and arsenate) bacteria. Functional analysis of the modified strains showed that: (i) the plasmid pARS1 can be used for the construction of strains with an increased resistance to arsenite [up to 20mM of As(III), (ii) the presence of the plasmid pAIO1 in bacteria previously unable to oxidize As(III) to As(V), contributes to the acquisition of arsenite oxidation abilities by these cells, (iii) the highest arsenite utilization rate are observed in the culture of strains harbouring both the plasmids pAIO1 and pARS1, (iv) the strains harbouring the plasmid pAIO1 were able to grow on arsenic-contaminated mine waters (∼ 3.0 mg As L(-1)) without any supplementation. PMID:25617684

  1. Ecological Genetics and Host Range Expansion by Busseola fusca (Lepidoptera: Noctuidae).

    PubMed

    Assefa, Y; Conlong, D E; Van Den Berg, J; Martin, L A

    2015-08-01

    The host plant range of pests can have important consequences for its evolution, and plays a critical role in the emergence and spread of a new pest outbreak. This study addresses the ecological genetics of the indigenous African maize stem borer, Busseola fusca (Fuller) (Lepidoptera: Noctuidae), in an attempt to investigate the evolutionary forces that may be involved in the recent host range expansion and establishment of this species in Ethiopian and southern African sugarcane. We used populations from Ethiopia, Zimbabwe, and South Africa to examine whether the host range expansion patterns shared by the Ethiopian and the southern African populations of B. fusca have evolved independently. Base-pair differences in the cytochrome oxidase I (COI) gene were used to characterize haplotype diversity and phylogenetic relationships. There were seven haplotypes among the 30 sequenced individuals collected on four host plant species from 17 localities in the four countries. Of the seven COI haplotypes identified, the two major ones occurred in both sugarcane and maize. Genetic analyses revealed no detectable genetic differentiation between southern African B. fusca populations from maize and sugarcane (FST = 0.019; P = 0.24). However, there was strong evidence of variation in genetic composition between populations of the pest from different geographic regions (FST = 0.948; P < 0.001). The main implication of these findings is that the B. fusca populations in maize in southern Africa are more likely to shift to sugarcane, suggesting that ecological opportunity is an important factor in host plant range expansion by a pest. PMID:26314073

  2. Does scavenging extend the host range of entomopathogenic nematodes (Nematoda: Steinernematidae)?

    PubMed

    Půza, Vladimír; Mrácek, Zdenĕk

    2010-05-01

    Living and freeze-killed natural and laboratory hosts, with different susceptibility to entomopathogenic nematodes, were exposed to the larvae of Steinernema affine and Steinernema kraussei in two different experimental arenas (Eppendorf tubes, Petri dishes), and the success of the colonisation and eventual progeny production were observed. Both nematodes were able to colonise both living and dead larvae of Galleria mellonella (Lepidoptera) and adult Blatella germanica (Blattodea) even though the progeny production in dead hosts was lower on average. Living carabid beetles, Poecilus cupreus, and elaterid larvae (Coleoptera) were resistant to the infection, however, both nematodes were able to colonise and multiply in several dead P. cupreus and in a majority of dead elaterid larvae. By scavenging, EPNs can utilise cadavers of insects that are naturally resistant to EPN infection, and so broaden their host range. PMID:20085768

  3. Gene organization and transcription of TED, a lepidopteran retrotransposon integrated within the baculovirus genome.

    PubMed Central

    Friesen, P D; Nissen, M S

    1990-01-01

    A single copy of the retrotransposon TED, from the moth Trichoplusia ni (a lepidopteran noctuid), was identified within the DNA genome of the baculovirus Autographa californica nuclear polyhedrosis virus. Determination of the complete nucleotide sequence (7,510 base pairs) of the integrated copy indicated that TED belongs to the family of retrotransposons that includes Drosophila melanogaster elements 17.6 and gypsy and thus represents the first nondipteran member of this invertebrate group to be identified. The internal portion of TED, flanked by long terminal repeats (LTRs), is composed of three long open reading frames comparable in size and location to the gag, pol, and env genes of the vertebrate retroviruses. Sequence similarity with the dipteran elements was the highest within individual domains of TED open reading frame 2 (pol region) that are also conserved among the retroviruses and encode protease, reverse transcriptase, and integrase functions, respectively. Mapping the 5' and 3' termini of TED RNAs indicated that the LTRs have a retroviral U3-R-U5 structural organization that is capable of directing the synthesis of transcripts that represent potential substrates for reverse transcription and intermediates in transposition. Abundant RNAs were also initiated from a site within the 5' LTR that matches the consensus motif for the promoter of late, hyperexpressed baculovirus genes. The presence of this viruslike promoter within TED and its subsequent activation only after integration within the viral genome suggest a possible symbiotic relationship with the baculovirus that could extend transposon host range. Images PMID:1692964

  4. Host range and in vitro lysis of Listeria monocytogenes seafood isolates by bacteriophages.

    PubMed

    Arachchi, Geevika J Ganegama; Cruz, Cristina D; Dias-Wanigasekera, Beatrice M; McIntyre, Lynn; Billington, Craig; Hudson, Andrew; Flint, Steve H; Mutukumira, Anthony N

    2014-12-01

    Listeria-infecting bacteriophages (listeriaphages) can be used to control Listeria monocytogenes in the food industry. However, the sensitivity of many of seafood-borne Listeria strains to phages has not been reported. This research investigated the host ranges of three listeriaphages (FWLLm1, FWLLm3 and FWLLm5) by the formation of lytic zones and plaques on host lawns and in vitro lysis kinetics of listeriaphage FWLLm3. The study also predicted the phage titres required to lyse host cells. The host ranges of the phages were determined using 50 L. monocytogenes strains, of which 48 were isolated from the seafood industry and two from clinical cases. Of the 50 strains, 36 were tested at 25 and 30 ℃ and the remainder (14) at 15 and 25 ℃. Based on the formation of either discrete plaques or lytic zones (host kill zones), the host ranges of FWLLm1, FWLLm3 and FWLLm5 were about 87%, 81% and 87%, respectively, at 25 ℃. Six L. monocytogenes strains from the seafood environment were insensitive to all three phages, while the other seafood strains (42) were phage-sensitive. The adsorption rate constant (k value) of listeriaphage FWLLm3 was between 1.2 × 10(-9) and 1.6 × 10(-9 )ml/min across four host strains in tryptic soy broth at 25 ℃. The cultures (at 3-4 log colony-forming unit (CFU/ml) were completely lysed (<1 log CFU/ml) when cultures were infected with FWLLm3 at > 8.7 log phage-forming units (PFU/ml) for 30 min. Re-growth of phage-infected cultures was not detected after 24 h. The effective empirical phage titre was similar to the calculated titre using a kinetic model. Results indicate the potential use of the three phages for controlling L. monocytogenes strains in seafood processing environments. PMID:23908393

  5. Phylogenetic relationships and host range of Rhizobium spp. that nodulate Phaseolus vulgaris L.

    PubMed Central

    Hernandez-Lucas, I; Segovia, L; Martinez-Romero, E; Pueppke, S G

    1995-01-01

    We determined the nucleotide sequences of 16S rRNA gene segments from five Rhizobium strains that have been isolated from tropical legume species. All share the capacity to nodulate Phaseolus vulgaris L., the common bean. Phylogenetic analysis confirmed that these strains are of two different chromosomal lineages. We defined the host ranges of two strains of Rhizobium etli and three strains of R. tropici, comparing them with those of the two most divergently related new strains. Twenty-two of the 43 tested legume species were nodulated by three or more of these strains. All seven strains have broad host ranges that include woody species such as Albizia lebbeck, Gliricidia maculata, and Leucaena leucocephala. PMID:7618891

  6. A tortoise-infecting picornavirus expands the host range of the family Picornaviridae

    PubMed Central

    Wellehan, James F. X.; Coleman, James K.; Kondov, Nikola O.; Deng, Xutao; Waltzek, Thomas B.; Reuter, Gábor; Knowles, Nick J.; Delwart, Eric

    2015-01-01

    While picornaviruses can cause diseases in many mammals, little is known of their host range for replication in non-mammalian vertebrates. Here, a picornavirus in liver and kidney tissues from diseased Sulawesi tortoises (Indotestudo forsteni) was genetically characterized. Tortoise rafivirus A (ToRaV-A, KJ415177) represents a potential new genus in the family Picornaviridae, for which we propose the name “Rafivirus”. Our finding confirms the susceptibility of reptiles to picornaviruses. PMID:25721297

  7. Host range and properties of the Pseudomonas aeruginosa R factor R1822.

    PubMed

    Olsen, R H; Shipley, P

    1973-02-01

    R1822, a plasmid specifying multiple drug resistances, has been transferred to a variety of species representative of related and unrelated genera. The host range of the plasmid includes Enterobacteriaceae, soil saprophytes, Neisseria perflava, and photosynthetic bacteria. With the acquisition of drug resistance(s), these strains became sensitive to a small, ribonuclease-sensitive bacteriophage, designated PRR1, isolated by enrichment from sewage. PMID:4632321

  8. Short- and long-range cues used by ground-dwelling parasitoids to find their host

    NASA Astrophysics Data System (ADS)

    Goubert, C.; Josso, C.; Louâpre, P.; Cortesero, A. M.; Poinsot, D.

    2013-02-01

    Parasitoids of phytophagous insects face a detectability-reliability dilemma when foraging for hosts. Plant-related cues are easily detectable, but do not guarantee the presence of the host. Host-related cues are very reliable, but much harder to detect from a distance. Little is known in particular about the way coleopteran parasitoid females use these cues when foraging for a suitable place to lay their eggs. The question is of interest because, unlike hymenopteran larvae, coleopteran parasitoid larvae are highly mobile and able to forage for hosts on their own. We assessed whether females of the parasitoid rove beetle Aleochara bipustulata (L.) (Coleoptera: Staphylinidae) are attracted to plant (Swede roots, Brassica napus) and host-related cues [pupae of the cabbage root fly Delia radicum (L.) (Diptera: Anthomyiidae)]. In the field, A. bipustulata adult females were captured in selective pitfall traps containing pieces of roots damaged by D. radicum larvae, but not in traps containing pieces of healthy roots or D. radicum pupae. However, in the laboratory, the odour of D. radicum pupae attracted A. bipustulata females to mini-pitfalls. Video monitoring in the laboratory showed that foraging A. bipustulata females preferred a zone containing D. radicum pupae and larval tracks rather than one containing an extract of D. radicum-infested roots. Our results suggest a behavioural sequence where A. bipustulata females use plant-related cues at a distance, but then switch their preference to host-related cues at a close range. This would be the first observation of this behaviour in coleopteran parasitoids.

  9. Divergent Nod-Containing Bradyrhizobium sp. DOA9 with a Megaplasmid and its Host Range

    PubMed Central

    Teamtisong, Kamonluck; Songwattana, Pongpan; Noisangiam, Rujirek; Piromyou, Pongdet; Boonkerd, Nantakorn; Tittabutr, Panlada; Minamisawa, Kiwamu; Nantagij, Achara; Okazaki, Shin; Abe, Mikiko; Uchiumi, Toshiki; Teaumroong, Neung

    2014-01-01

    Bradyrhizobium sp. DOA9, a non-photosynthetic bacterial strain originally isolated from the root nodules of the legume Aeschynomene americana, is a divergent nod-containing strain. It exhibits a broad host range, being able to colonize and efficiently nodulate the roots of most plants from the Dalbergioid, Millettioid, and Robinioid tribes (7 species of Papilionoideae). In all cases, nodulation was determinate. The morphology and size of DOA9 bacteroids isolated from the nodules of various species of Papilionoideae were indistinguishable from the free-living form. However, they were spherical in Arachis hypogaea nodules. GusA-tagged DOA9 also colonized rice roots as endophytes. Since broad-host-range legume symbionts often carry multiple replicons in their genome, we analyzed the replicons for symbiosis genes by electrophoresis. DOA9 carried two replicons, a chromosome (cDOA9) and single megaplasmid (pDOA9) larger than 352 kb. The genes for nodulation (nodA, B, C) and nitrogen fixation (nifH) were localized on the megaplasmid. Southern blot hybridization revealed two copies of nodA on the megaplasmid, single copies of nodB and C on the megaplasmid, and one copy each of nifH on the chromosome and megaplasmid. These results suggested that Bradyrhizobium sp. DOA9 may have the unusual combination of a broad host range, bacteroid differentiation, and symbiosis-mediating replicons. PMID:25283477

  10. Ecological host-range of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of Dioscorea bulbifera L.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Open-field host-specificity testing assesses the host-range of a biological control agent in a setting that permits the agent to use its full complement of host-seeking behaviors. This form of testing, particularly when it includes a no-choice phase in which the target weed is killed, may provide th...

  11. Reduced stability and intracellular transport of dsRNA contribute to poor RNAi response in lepidopteran insects

    PubMed Central

    Shukla, Jayendra Nath; Kalsi, Megha; Sethi, Amit; Narva, Kenneth E.; Fishilevich, Elane; Singh, Satnam; Mogilicherla, Kanakachari; Palli, Subba Reddy

    2016-01-01

    ABSTRACT RNA interference (RNAi) has become a widely used reverse genetic tool to study gene function in eukaryotic organisms and is being developed as a technology for insect pest management. The efficiency of RNAi varies among organisms. Insects from different orders also display differential efficiency of RNAi, ranging from highly efficient (coleopterans) to very low efficient (lepidopterans). We investigated the reasons for varying RNAi efficiency between lepidopteran and coleopteran cell lines and also between the Colorado potato beetle, Leptinotarsa decemlineata and tobacco budworm, Heliothis virescens. The dsRNA either injected or fed was degraded faster in H. virescens than in L. decemlineata. Both lepidopteran and coleopteran cell lines and tissues efficiently took up the dsRNA. Interestingly, the dsRNA administered to coleopteran cell lines and tissues was taken up and processed to siRNA whereas the dsRNA was taken up by lepidopteran cell lines and tissues but no siRNA was detected in the total RNA isolated from these cell lines and tissues. The data included in this paper showed that the degradation and intracellular transport of dsRNA are the major factors responsible for reduced RNAi efficiency in lepidopteran insects. PMID:27245473

  12. Reduced stability and intracellular transport of dsRNA contribute to poor RNAi response in lepidopteran insects.

    PubMed

    Shukla, Jayendra Nath; Kalsi, Megha; Sethi, Amit; Narva, Kenneth E; Fishilevich, Elane; Singh, Satnam; Mogilicherla, Kanakachari; Palli, Subba Reddy

    2016-07-01

    RNA interference (RNAi) has become a widely used reverse genetic tool to study gene function in eukaryotic organisms and is being developed as a technology for insect pest management. The efficiency of RNAi varies among organisms. Insects from different orders also display differential efficiency of RNAi, ranging from highly efficient (coleopterans) to very low efficient (lepidopterans). We investigated the reasons for varying RNAi efficiency between lepidopteran and coleopteran cell lines and also between the Colorado potato beetle, Leptinotarsa decemlineata and tobacco budworm, Heliothis virescens. The dsRNA either injected or fed was degraded faster in H. virescens than in L. decemlineata. Both lepidopteran and coleopteran cell lines and tissues efficiently took up the dsRNA. Interestingly, the dsRNA administered to coleopteran cell lines and tissues was taken up and processed to siRNA whereas the dsRNA was taken up by lepidopteran cell lines and tissues but no siRNA was detected in the total RNA isolated from these cell lines and tissues. The data included in this paper showed that the degradation and intracellular transport of dsRNA are the major factors responsible for reduced RNAi efficiency in lepidopteran insects. PMID:27245473

  13. Host-Range Dynamics of Cochliobolus lunatus: From a Biocontrol Agent to a Severe Environmental Threat

    PubMed Central

    Louis, Bengyella; Waikhom, Sayanika Devi; Roy, Pranab; Bhardwaj, Pardeep Kumar; Sharma, Chandradev K.; Singh, Mohendro Wakambam; Talukdar, Narayan Chandra

    2014-01-01

    We undertook an investigation to advance understanding of the host-range dynamics and biocontrol implications of Cochliobolus lunatus in the past decade. Potato (Solanum tuberosum L) farms were routinely surveyed for brown-to-black leaf spot disease caused by C. lunatus. A biphasic gene data set was assembled and databases were mined for reported hosts of C. lunatus in the last decade. The placement of five virulent strains of C. lunatus causing foliar necrosis of potato was studied with microscopic and phylogenetic tools. Analysis of morphology showed intraspecific variations in stromatic tissues among the virulent strains causing foliar necrosis of potato. A maximum likelihood inference based on GPDH locus separated C. lunatus strains into subclusters and revealed the emergence of unclustered strains. The evolving nutritional requirement of C. lunatus in the last decade is exhibited by the invasion of vertebrates, invertebrates, dicots, and monocots. Our results contribute towards a better understanding of the host-range dynamics of C. lunatus and provide useful implications on the threat posed to the environment when C. lunatus is used as a mycoherbicide. PMID:24987680

  14. Secreted effectors in Toxoplasma gondii and related species: determinants of host range and pathogenesis?

    PubMed Central

    English, E D; Adomako-Ankomah, Y; Boyle, J P

    2015-01-01

    Recent years have witnessed the discovery of a number of secreted proteins in Toxoplasma gondii that play important roles in host–pathogen interactions and parasite virulence, particularly in the mouse model. However, the role that these proteins play in driving the unique features of T. gondii compared to some of its nearest apicomplexan relatives (Hammondia hammondi and Neospora caninum) is unknown. These unique features include distinct dissemination characteristics in vivo and a vast host range. In this review we comprehensively survey what is known about disease outcome, the host response and host range for T. gondii, H. hammondi, and N. caninum. We then review what is presently known about recently identified secreted virulence effectors in these three genetically related, but phenotypically distinct, species. Finally we exploit the existence of genome sequences for these three organisms and discuss what is known about the presence, and functionality, of key T. gondii effectors in these three species. PMID:25655311

  15. Prediction of Steps in the Evolution of Variola Virus Host Range

    PubMed Central

    Smithson, Chad; Purdy, Alex; Verster, Adrian J.; Upton, Chris

    2014-01-01

    Variola virus, the agent of smallpox, has a severely restricted host range (humans) but a devastatingly high mortality rate. Although smallpox has been eradicated by a World Health Organization vaccination program, knowledge of the evolutionary processes by which human super-pathogens such as variola virus arise is important. By analyzing the evolution of variola and other closely related poxviruses at the level of single nucleotide polymorphisms we detected a hotspot of genome variation within the smallpox ortholog of the vaccinia virus O1L gene, which is known to be necessary for efficient replication of vaccinia virus in human cells. These mutations in the variola virus ortholog and the subsequent loss of the functional gene from camelpox virus and taterapox virus, the two closest relatives of variola virus, strongly suggest that changes within this region of the genome may have played a key role in the switch to humans as a host for the ancestral virus and the subsequent host-range restriction that must have occurred to create the phenotype exhibited by smallpox. PMID:24626337

  16. "Candidatus Liberibacter asiaticus" prophage late genes may limit host range and culturability.

    PubMed

    Fleites, Laura A; Jain, Mukesh; Zhang, Shujian; Gabriel, Dean W

    2014-10-01

    "Candidatus Liberibacter asiaticus" is an uncultured alphaproteobacterium that systemically colonizes its insect host both inter- and intracellularly and also causes a severe, crop-destroying disease of citrus called huanglongbing, or citrus "greening." In planta, "Ca. Liberibacter asiaticus" is also systemic but phloem limited. "Ca. Liberibacter asiaticus" strain UF506 carries two predicted prophages, SC1 and SC2. Bacteriophage particles have been observed in experimentally "Ca. Liberibacter asiaticus"-infected periwinkle but not in any other host. Comparative gene expression analysis of predicted SC1 late genes showed a much higher level of late gene expression, including holin transcripts (SC1_gp110), in "Ca. Liberibacter asiaticus"-infected periwinkle relative to "Ca. Liberibacter asiaticus"-infected citrus. To functionally characterize predicted holin and endolysin activity, SC1_gp110 and two predicted endolysins, one within SC1 (SC1_gp035) and another well outside the predicted prophage region (CLIBASIA_04790), were cloned and expressed in Escherichia coli. Both SC1 genes inhibited bacterial growth consistent with holin and endolysin function. The holin (SC1_gp110) promoter region was fused with a uidA reporter on pUFR071, a wide bacterial host range (repW) replicon, and used to transform Liberibacter crescens strain BT-1 by electroporation. BT-1 is the only liberibacter strain cultured to date and was used as a proxy for "Ca. Liberibacter asiaticus." pUFR071 was >95% stable without selection in BT-1 for over 20 generations. The reporter construct exhibited strong constitutive glucuronidase (GUS) activity in culture-grown BT-1 cells. However, GUS reporter activity in BT-1 was suppressed in a dose-dependent manner by crude aqueous extracts from psyllids. Taken together with plant expression data, these observations indicate that "Ca. Liberibacter asiaticus" prophage activation may limit "Ca. Liberibacter asiaticus" host range and culturability. PMID:25063651

  17. The carboxyl-terminal domain of large T antigen rescues SV40 host range activity in trans independent of acetylation.

    PubMed

    Poulin, Danielle L; DeCaprio, James A

    2006-05-25

    The host range activity of SV40 has been described as the inability of mutant viruses with deletions in the C terminal region of large T Ag to replicate in certain types of African green monkey kidney cells. We constructed new mutant viruses expressing truncated T Ag proteins and found that these mutant viruses exhibited the host range phenotype. The host range phenotype was independent of acetylation of T Ag at lysine 697. Co-expression of the C terminal domain of T Ag (aa 627-708) in trans increased both T Ag and VP1 mRNA as well as protein levels for host range mutant viruses in the restrictive cell type. In addition, the T Ag 627-708 fragment promoted the productive lytic infection of host range mutant viruses in the nonpermissive cell type. The carboxyl-terminal region of T Ag contains a biological function essential for the SV40 viral life cycle. PMID:16510165

  18. Development of a gene silencing DNA vector derived from a broad host range geminivirus

    PubMed Central

    Golenberg, Edward M; Sather, D Noah; Hancock, Leandria C; Buckley, Kenneth J; Villafranco, Natalie M; Bisaro, David M

    2009-01-01

    Background Gene silencing is proving to be a powerful tool for genetic, developmental, and physiological analyses. The use of viral induced gene silencing (VIGS) offers advantages to transgenic approaches as it can be potentially applied to non-model systems for which transgenic techniques are not readily available. However, many VIGS vectors are derived from Gemini viruses that have limited host ranges. We present a new, unipartite vector that is derived from a curtovirus that has a broad host range and will be amenable to use in many non-model systems. Results The construction of a gene silencing vector derived from the geminivirus Beet curly top virus (BCTV), named pWSRi, is reported. Two versions of the vector have been developed to allow application by biolistic techniques or by agro-infiltration. We demonstrate its ability to silence nuclear genes including ribulose bisphosphate carboxylase small subunit (rbcS), transketolase, the sulfur allele of magnesium chelatase (ChlI), and two homeotic transcription factors in spinach or tomato by generating gene-specific knock-down phenotypes. Onset of phenotypes occurred 3 to 12 weeks post-inoculation, depending on the target gene, in organs that developed after the application. The vector lacks movement genes and we found no evidence for significant spread from the site of inoculation. However, viral amplification in inoculated tissue was detected and is necessary for systemic silencing, suggesting that signals generated from active viral replicons are efficiently transported within the plant. Conclusion The unique properties of the pWSRi vector, the ability to silence genes in meristem tissue, the separation of virus and silencing phenotypes, and the broad natural host range of BCTV, suggest that it will have wide utility. PMID:19573239

  19. Evidence that Lactobacillus casei insertion element ISL1 has a narrow host range.

    PubMed Central

    Shimizu-Kadota, M; Flickinger, J L; Chassy, B M

    1988-01-01

    The 1.3-kilobase-pair insertion element ISL1, originally isolated from Lactobacillus casei S-1, was found to have an extremely restricted host range. By DNA-DNA hybrizations performed with Southern transfers by using a cloned internal fragment of ISL1 as a molecular probe, it was found that only 3 of 19 L. casei strains examined contained sequences that hybridized to the ISL1 probe. In two of these, the hybridizing sequences were found on lactose plasmids. No homologous sequences were detected in a survey of 14 other Lactobacillus strains (9 species) and 15 strains of other bacteria (8 genera, 12 species). Images PMID:2844733

  20. A Single Residue in Ebola Virus Receptor NPC1 Influences Cellular Host Range in Reptiles.

    PubMed

    Ndungo, Esther; Herbert, Andrew S; Raaben, Matthijs; Obernosterer, Gregor; Biswas, Rohan; Miller, Emily Happy; Wirchnianski, Ariel S; Carette, Jan E; Brummelkamp, Thijn R; Whelan, Sean P; Dye, John M; Chandran, Kartik

    2016-01-01

    Filoviruses are the causative agents of an increasing number of disease outbreaks in human populations, including the current unprecedented Ebola virus disease (EVD) outbreak in western Africa. One obstacle to controlling these epidemics is our poor understanding of the host range of filoviruses and their natural reservoirs. Here, we investigated the role of the intracellular filovirus receptor, Niemann-Pick C1 (NPC1) as a molecular determinant of Ebola virus (EBOV) host range at the cellular level. Whereas human cells can be infected by EBOV, a cell line derived from a Russell's viper (Daboia russellii) (VH-2) is resistant to infection in an NPC1-dependent manner. We found that VH-2 cells are resistant to EBOV infection because the Russell's viper NPC1 ortholog bound poorly to the EBOV spike glycoprotein (GP). Analysis of panels of viper-human NPC1 chimeras and point mutants allowed us to identify a single amino acid residue in NPC1, at position 503, that bidirectionally influenced both its binding to EBOV GP and its viral receptor activity in cells. Significantly, this single residue change perturbed neither NPC1's endosomal localization nor its housekeeping role in cellular cholesterol trafficking. Together with other recent work, these findings identify sequences in NPC1 that are important for viral receptor activity by virtue of their direct interaction with EBOV GP and suggest that they may influence filovirus host range in nature. Broader surveys of NPC1 orthologs from vertebrates may delineate additional sequence polymorphisms in this gene that control susceptibility to filovirus infection. IMPORTANCE Identifying cellular factors that determine susceptibility to infection can help us understand how Ebola virus is transmitted. We asked if the EBOV receptor Niemann-Pick C1 (NPC1) could explain why reptiles are resistant to EBOV infection. We demonstrate that cells derived from the Russell's viper are not susceptible to infection because EBOV cannot bind to

  1. A Single Residue in Ebola Virus Receptor NPC1 Influences Cellular Host Range in Reptiles

    PubMed Central

    Ndungo, Esther; Herbert, Andrew S.; Raaben, Matthijs; Obernosterer, Gregor; Biswas, Rohan; Miller, Emily Happy; Wirchnianski, Ariel S.; Carette, Jan E.; Brummelkamp, Thijn R.; Whelan, Sean P.

    2016-01-01

    ABSTRACT Filoviruses are the causative agents of an increasing number of disease outbreaks in human populations, including the current unprecedented Ebola virus disease (EVD) outbreak in western Africa. One obstacle to controlling these epidemics is our poor understanding of the host range of filoviruses and their natural reservoirs. Here, we investigated the role of the intracellular filovirus receptor, Niemann-Pick C1 (NPC1) as a molecular determinant of Ebola virus (EBOV) host range at the cellular level. Whereas human cells can be infected by EBOV, a cell line derived from a Russell’s viper (Daboia russellii) (VH-2) is resistant to infection in an NPC1-dependent manner. We found that VH-2 cells are resistant to EBOV infection because the Russell’s viper NPC1 ortholog bound poorly to the EBOV spike glycoprotein (GP). Analysis of panels of viper-human NPC1 chimeras and point mutants allowed us to identify a single amino acid residue in NPC1, at position 503, that bidirectionally influenced both its binding to EBOV GP and its viral receptor activity in cells. Significantly, this single residue change perturbed neither NPC1’s endosomal localization nor its housekeeping role in cellular cholesterol trafficking. Together with other recent work, these findings identify sequences in NPC1 that are important for viral receptor activity by virtue of their direct interaction with EBOV GP and suggest that they may influence filovirus host range in nature. Broader surveys of NPC1 orthologs from vertebrates may delineate additional sequence polymorphisms in this gene that control susceptibility to filovirus infection. IMPORTANCE Identifying cellular factors that determine susceptibility to infection can help us understand how Ebola virus is transmitted. We asked if the EBOV receptor Niemann-Pick C1 (NPC1) could explain why reptiles are resistant to EBOV infection. We demonstrate that cells derived from the Russell’s viper are not susceptible to infection because EBOV

  2. Bacteriophage Typing of Salmonella. I. Isolation and Host Range Study of Bacteriophages

    PubMed Central

    Ibrahim, Abdel Aziz E.

    1969-01-01

    A series of bacteriophages, lytic for bacteria belonging to the genera Escherichia and Salmonella, were isolated. The phages were isolated from fecal samples, intestinal contents of turkey poults, and carrier cultures of S. typhimurium, S. typhimurium var copenhagen, S. heidelberg, and E. coli. The feasibility of using different habitats as sources of Salmonella phages was evaluated. The carrier cultures were the most promising source for phages active on the serotypes for which the phages were sought. A host range study of the isolated phages was made. Eight phages were selected to develop a phage typing scheme for S. typhimurium, S. typhimurium var copenhagen, and S. heidelberg. PMID:4907005

  3. A genetically novel, narrow-host-range isolate of cucumber mosaic virus (CMV) from rosemary.

    PubMed

    Tepfer, Mark; Girardot, Gregory; Fénéant, Lucie; Ben Tamarzizt, Hana; Verdin, Eric; Moury, Benoît; Jacquemond, Mireille

    2016-07-01

    An isolate of cucumber mosaic virus (CMV), designated CMV-Rom, was isolated from rosemary (Rosmarinus officinalis) plants in several locations near Avignon, France. Laboratory studies showed that, unlike typical CMV isolates, CMV-Rom has a particularly narrow host range. It could be transmitted by aphids Aphis gossypii and Myzus persicae, but with low efficacy compared to a typical CMV isolate. Phylogenetic analysis of the nucleotide sequences of the CMV-Rom genomic RNAs shows that this isolate does not belong to any of the previously described CMV subgroups, IA, IB, II or III. PMID:27138549

  4. Clarification on Host Range of Didymella pinodes the Causal Agent of Pea Ascochyta Blight.

    PubMed

    Barilli, Eleonora; Cobos, Maria José; Rubiales, Diego

    2016-01-01

    Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum) worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates of D. fabae, D. rabiei, and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested. D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum, and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa, and V. articulata. DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here, D

  5. Clarification on Host Range of Didymella pinodes the Causal Agent of Pea Ascochyta Blight

    PubMed Central

    Barilli, Eleonora; Cobos, Maria José; Rubiales, Diego

    2016-01-01

    Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum) worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates of D. fabae, D. rabiei, and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested. D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum, and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa, and V. articulata. DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here, D

  6. Genetic characterization and phylogenetic analysis of host-range genes of Camelpox virus isolates from India.

    PubMed

    Bera, B C; Barua, S; Shanmugasundaram, K; Anand, T; Riyesh, T; Vaid, R K; Virmani, N; Kundu, S; Yadav, N K; Malik, P; Singh, R K

    2015-09-01

    Camelpox virus (CMLV), a close variant of variola virus (VARV) infects camels worldwide. The zoonotic infections reported from India signify the need to study the host-range genes-responsible for host tropism. We report sequence and phylogenetic analysis of five host-range genes: cytokine response modifier B (crmB), chemokine binding protein (ckbp), viral schlafen-like (v-slfn), myxomavirus T4-like (M-T4-like) and b5r of CMLVs isolated from outbreaks in India. Comparative analysis revealed that these genes are conserved among CMLVs and shared 94.5-100 % identity at both nucleotide (nt) and amino acid (aa) levels. All genes showed identity (59.3-98.4 %) with cowpox virus (CPXV) while three genes-crmB, ckbp and b5r showed similarity (92-96.5 %) with VARVs at both nt and aa levels. Interestingly, three consecutive serine residue insertions were observed in CKBP protein of CMLV-Delhi09 isolate which was similar to CPXV-BR and VACVs, besides five point mutations (K53Q, N67I, F84S, A127T and E182G) were also similar to zoonotic OPXVs. Further, few inconsistent point mutation(s) were also observed in other gene(s) among Indian CMLVs. These indicate that different strains of CMLVs are circulating in India and these mutations could play an important role in adaptation of CMLVs in humans. The phylogeny revealed clustering of all CMLVs together except CMLV-Delhi09 which grouped separately due to the presence of specific point mutations. However, the topology of the concatenated phylogeny showed close evolutionary relationship of CMLV with VARV and TATV followed by CPXV-RatGer09/1 from Germany. The availability of this genetic information will be useful in unveiling new strategies to control emerging zoonotic poxvirus infections. PMID:26396982

  7. Genetic mutations of avian leukosis virus subgroup J strains extended their host range.

    PubMed

    Shen, Yanwei; Cai, Liming; Wang, Yanming; Wei, Rongrong; He, Menglian; Wang, Shanhui; Wang, Guihua; Cheng, Ziqiang

    2014-03-01

    The genetic diversity of avian leukosis virus subgroup J (ALV-J) is determined not only by the env gene, but also by its 3' UTR and 3' LTR. They all play important roles in extending the host range and tumour development. In the present study, one ALV-J strain (ZB110604-6) from Black-Bone Silky Fowl (BSF) and three ALV-J strains (ZB110604-3/4/5) from grey partridge (GP), which bore multiple tumours and breed in one house of Farm A, were demonstrated extending their host to GP, while two other ALV-J strains (LC110515-3/4) from BSF of Farm B could not infect the embryo fibroblast of GP. The BSF is a unique species of chicken in China, while the GP is a close relative of the pheasant that previously demonstrated resistance to ALV-J. Histopathology showed that various tumours were induced by ALV-J in the two species. Phylogenetic tree analysis showed that the isolates from Farms A and B, rather than species, belong to two different clusters of ALV-J. Genetic mutations analysis revealed that the isolates obtained from Farm A showed a higher frequency of mutation in the hypervariable region 2 domain than in other variable regions of the gp85 gene. From the nucleotide alignment of the 3' UTR and 3' LTR gene, and the spectrum of tumours observed in this study, we speculate that the deletions or mutations in the redundant transmembrane region, E element and U3 (CAAT boxes, CArG box and Y box) might associate with tumour formation and development. The extension of the host range of ALV-J to the GP suggested that housing different species together provides more opportunities for ALV-J to evolve rapidly. PMID:24272684

  8. Fundamental Host Range of Leptoypha hospita (Hemiptera: Tingidae), a Potential Biological Control Agent of Chinese Privet.

    PubMed

    Zhang, Yanzhuo; Hanula, James L; Horn, Scott; Jones, Cera; Kristine Braman, S; Sun, Jianghua

    2016-08-01

    Chinese privet, Ligustrum sinense Lour., is an invasive shrub within riparian areas of the southeastern United States. Biological control is considered the most suitable management option for Chinese privet. The potential host range of the lace bug, Leptoypha hospita Drake et Poor, was evaluated on the basis of adult feeding and oviposition, combined oviposition-nymphal development no-choice tests, nymphal development no-choice tests, multiple generation comparison on Forestiera pubescens Nutt. and L. sinense no-choice tests, and multiple-choice tests with 45 plant species in 13 families. No-choice tests showed that the host range of L. hospita was restricted to the tribe Oleeae. In adult feeding and oviposition no-choice tests, the bug fed and oviposited significantly more on Chinese privet than all other test plant species except for three native Forestiera spp., two nonnative Syringa spp., and another exotic Ligustrum sp. Among those, only F. pubescens supported complete development in numbers comparable to Chinese privet. However, when reared for multiple generations lace bugs reared on F. pubescens were smaller and had lower fecundity than those reared on L. sinense, suggesting F. pubescens is not an optimal host. In multiple-choice tests, L. hospita displayed a strong preference for feeding and ovipositing on Chinese privet over other test plant species, with the exception of the closely related nonnative Syringa spp. and its congenic species Ligustrum vulgare. The results of this study suggest that the risk to nontarget plant species in North America is minimal, and L. hospita would be a promising candidate for Chinese privet biological control. PMID:27325627

  9. Mountain pine beetle host-range expansion threatens the boreal forest.

    PubMed

    Cullingham, Catherine I; Cooke, Janice E K; Dang, Sophie; Davis, Corey S; Cooke, Barry J; Coltman, David W

    2011-05-01

    The current epidemic of the mountain pine beetle (MPB), an indigenous pest of western North American pine, has resulted in significant losses of lodgepole pine. The leading edge has reached Alberta where forest composition shifts from lodgepole to jack pine through a hybrid zone. The susceptibility of jack pine to MPB is a major concern, but there has been no evidence of host-range expansion, in part due to the difficulty in distinguishing the parentals and their hybrids. We tested the utility of a panel of microsatellite loci optimized for both species to classify lodgepole pine, jack pine and their hybrids using simulated data. We were able to accurately classify simulated individuals, and hence applied these markers to identify the ancestry of attacked trees. Here we show for the first time successful MPB attack in natural jack pine stands at the leading edge of the epidemic. This once unsuitable habitat is now a novel environment for MPB to exploit, a potential risk which could be exacerbated by further climate change. The consequences of host-range expansion for the vast boreal ecosystem could be significant. PMID:21457381

  10. Broad-host-range vector system for synthetic biology and biotechnology in cyanobacteria

    PubMed Central

    Taton, Arnaud; Unglaub, Federico; Wright, Nicole E.; Zeng, Wei Yue; Paz-Yepes, Javier; Brahamsha, Bianca; Palenik, Brian; Peterson, Todd C.; Haerizadeh, Farzad; Golden, Susan S.; Golden, James W.

    2014-01-01

    Inspired by the developments of synthetic biology and the need for improved genetic tools to exploit cyanobacteria for the production of renewable bioproducts, we developed a versatile platform for the construction of broad-host-range vector systems. This platform includes the following features: (i) an efficient assembly strategy in which modules released from 3 to 4 donor plasmids or produced by polymerase chain reaction are assembled by isothermal assembly guided by short GC-rich overlap sequences. (ii) A growing library of molecular devices categorized in three major groups: (a) replication and chromosomal integration; (b) antibiotic resistance; (c) functional modules. These modules can be assembled in different combinations to construct a variety of autonomously replicating plasmids and suicide plasmids for gene knockout and knockin. (iii) A web service, the CYANO-VECTOR assembly portal, which was built to organize the various modules, facilitate the in silico construction of plasmids, and encourage the use of this system. This work also resulted in the construction of an improved broad-host-range replicon derived from RSF1010, which replicates in several phylogenetically distinct strains including a new experimental model strain Synechocystis sp. WHSyn, and the characterization of nine antibiotic cassettes, four reporter genes, four promoters, and a ribozyme-based insulator in several diverse cyanobacterial strains. PMID:25074377

  11. Narrow-Host-Range Bacteriophages That Infect Rhizobium etli Associate with Distinct Genomic Types

    PubMed Central

    Santamaría, Rosa Isela; Bustos, Patricia; Sepúlveda-Robles, Omar; Lozano, Luis; Rodríguez, César; Fernández, José Luis; Juárez, Soledad; Kameyama, Luis; Guarneros, Gabriel; Dávila, Guillermo

    2014-01-01

    In this work, we isolated and characterized 14 bacteriophages that infect Rhizobium etli. They were obtained from rhizosphere soil of bean plants from agricultural lands in Mexico using an enrichment method. The host range of these phages was narrow but variable within a collection of 48 R. etli strains. We obtained the complete genome sequence of nine phages. Four phages were resistant to several restriction enzymes and in vivo cloning, probably due to nucleotide modifications. The genome size of the sequenced phages varied from 43 kb to 115 kb, with a median size of ∼45 to 50 kb. A large proportion of open reading frames of these phage genomes (65 to 70%) consisted of hypothetical and orphan genes. The remainder encoded proteins needed for phage morphogenesis and DNA synthesis and processing, among other functions, and a minor percentage represented genes of bacterial origin. We classified these phages into four genomic types on the basis of their genomic similarity, gene content, and host range. Since there are no reports of similar sequences, we propose that these bacteriophages correspond to novel species. PMID:24185856

  12. Genome Degradation in Brucella ovis Corresponds with Narrowing of Its Host Range and Tissue Tropism

    PubMed Central

    Tsolis, Renee M.; Seshadri, Rekha; Santos, Renato L.; Sangari, Felix J.; Lobo, Juan M. García; de Jong, Maarten F.; Ren, Qinghu; Myers, Garry; Brinkac, Lauren M.; Nelson, William C.; DeBoy, Robert T.; Angiuoli, Samuel; Khouri, Hoda; Dimitrov, George; Robinson, Jeffrey R.; Mulligan, Stephanie; Walker, Richard L.; Elzer, Philip E.; Hassan, Karl A.; Paulsen, Ian T.

    2009-01-01

    Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis. PMID:19436743

  13. Mountain pine beetle host-range expansion threatens the boreal forest

    PubMed Central

    Cullingham, Catherine I; Cooke, Janice E K; Dang, Sophie; Davis, Corey S; Cooke, Barry J; Coltman, David W

    2011-01-01

    The current epidemic of the mountain pine beetle (MPB), an indigenous pest of western North American pine, has resulted in significant losses of lodgepole pine. The leading edge has reached Alberta where forest composition shifts from lodgepole to jack pine through a hybrid zone. The susceptibility of jack pine to MPB is a major concern, but there has been no evidence of host-range expansion, in part due to the difficulty in distinguishing the parentals and their hybrids. We tested the utility of a panel of microsatellite loci optimized for both species to classify lodgepole pine, jack pine and their hybrids using simulated data. We were able to accurately classify simulated individuals, and hence applied these markers to identify the ancestry of attacked trees. Here we show for the first time successful MPB attack in natural jack pine stands at the leading edge of the epidemic. This once unsuitable habitat is now a novel environment for MPB to exploit, a potential risk which could be exacerbated by further climate change. The consequences of host-range expansion for the vast boreal ecosystem could be significant. PMID:21457381

  14. Is the optimal pH for membrane fusion in host cells by avian influenza viruses related to host range and pathogenicity?

    PubMed

    Okamatsu, Masatoshi; Motohashi, Yurie; Hiono, Takahiro; Tamura, Tomokazu; Nagaya, Kazuki; Matsuno, Keita; Sakoda, Yoshihiro; Kida, Hiroshi

    2016-08-01

    Influenza viruses isolated from wild ducks do not replicate in chickens. This fact is not explained solely by the receptor specificity of the hemagglutinin (HA) from such viruses for target host cells. To investigate this restriction in host range, the fusion activities of HA molecules from duck and chicken influenza viruses were examined. Influenza viruses A/duck/Mongolia/54/2001 (H5N2) (Dk/MNG) and A/chicken/Ibaraki/1/2005 (H5N2) (Ck/IBR), which replicate only in their primary hosts, were used. The optimal pH for membrane fusion of Ck/IBR was 5.9, higher than that of Dk/MNG at 4.9. To assess the relationship between the optimal pH for fusion and the host range of avian influenza viruses, the optimal pH for fusion of 55 influenza virus strains isolated from ducks and chickens was examined. No correlation was found between the host range and optimal pH for membrane fusion by the viruses, and this finding applied also to the H5N1 highly pathogenic avian influenza viruses. The optimal pH for membrane fusion for avian influenza viruses was shown to not necessarily be correlated with their host range or pathogenicity in ducks and chickens. PMID:27231009

  15. “Candidatus Liberibacter asiaticus” Prophage Late Genes May Limit Host Range and Culturability

    PubMed Central

    Fleites, Laura A.; Jain, Mukesh; Zhang, Shujian

    2014-01-01

    “Candidatus Liberibacter asiaticus” is an uncultured alphaproteobacterium that systemically colonizes its insect host both inter- and intracellularly and also causes a severe, crop-destroying disease of citrus called huanglongbing, or citrus “greening.” In planta, “Ca. Liberibacter asiaticus” is also systemic but phloem limited. “Ca. Liberibacter asiaticus” strain UF506 carries two predicted prophages, SC1 and SC2. Bacteriophage particles have been observed in experimentally “Ca. Liberibacter asiaticus”-infected periwinkle but not in any other host. Comparative gene expression analysis of predicted SC1 late genes showed a much higher level of late gene expression, including holin transcripts (SC1_gp110), in “Ca. Liberibacter asiaticus”-infected periwinkle relative to “Ca. Liberibacter asiaticus”-infected citrus. To functionally characterize predicted holin and endolysin activity, SC1_gp110 and two predicted endolysins, one within SC1 (SC1_gp035) and another well outside the predicted prophage region (CLIBASIA_04790), were cloned and expressed in Escherichia coli. Both SC1 genes inhibited bacterial growth consistent with holin and endolysin function. The holin (SC1_gp110) promoter region was fused with a uidA reporter on pUFR071, a wide bacterial host range (repW) replicon, and used to transform Liberibacter crescens strain BT-1 by electroporation. BT-1 is the only liberibacter strain cultured to date and was used as a proxy for “Ca. Liberibacter asiaticus.” pUFR071 was >95% stable without selection in BT-1 for over 20 generations. The reporter construct exhibited strong constitutive glucuronidase (GUS) activity in culture-grown BT-1 cells. However, GUS reporter activity in BT-1 was suppressed in a dose-dependent manner by crude aqueous extracts from psyllids. Taken together with plant expression data, these observations indicate that “Ca. Liberibacter asiaticus” prophage activation may limit “Ca. Liberibacter asiaticus” host

  16. Characterization of novel virulent broad-host-range phages of Xylella fastidiosa and Xanthomonas.

    PubMed

    Ahern, Stephen J; Das, Mayukh; Bhowmick, Tushar Suvra; Young, Ry; Gonzalez, Carlos F

    2014-01-01

    The xylem-limited bacterium Xylella fastidiosa is the causal agent of several plant diseases, most notably Pierce's disease of grape and citrus variegated chlorosis. We report the isolation and characterization of the first virulent phages for X. fastidiosa, siphophages Sano and Salvo and podophages Prado and Paz, with a host range that includes Xanthomonas spp. Phages propagated on homologous hosts had observed adsorption rate constants of ~4 × 10(-12) ml cell(-1) min(-1) for X. fastidiosa strain Temecula 1 and ~5 × 10(-10) to 7 × 10(-10) ml cell(-1) min(-1) for Xanthomonas strain EC-12. Sano and Salvo exhibit >80% nucleotide identity to each other in aligned regions and are syntenic to phage BcepNazgul. We propose that phage BcepNazgul is the founding member of a novel phage type, to which Sano and Salvo belong. The lysis genes of the Nazgul-like phage type include a gene that encodes an outer membrane lipoprotein endolysin and also spanin gene families that provide insight into the evolution of the lysis pathway for phages of Gram-negative hosts. Prado and Paz, although exhibiting no significant DNA homology to each other, are new members of the phiKMV-like phage type, based on the position of the single-subunit RNA polymerase gene. The four phages are type IV pilus dependent for infection of both X. fastidiosa and Xanthomonas. The phages may be useful as agents for an effective and environmentally responsible strategy for the control of diseases caused by X. fastidiosa. PMID:24214944

  17. Sugarcane Aphid (Hemiptera: Aphididae): Host Range and Sorghum Resistance Including Cross-Resistance From Greenbug Sources.

    PubMed

    Armstrong, J Scott; Rooney, William L; Peterson, Gary C; Villenueva, Raul T; Brewer, Michael J; Sekula-Ortiz, Danielle

    2015-04-01

    The graminous host range and sources of sorghum [Sorghum bicolor (L.) Moench.] plant resistance, including cross-resistance from greenbug, Schizaphis graminum (Rondani), were studied for the newly emerging sugarcane aphid, Melanaphis sacchari (Zehntner), in greenhouse no-choice experiments and field evaluations. The sugarcane aphid could not survive on field corn, Zea mays (L.), Teff grass, Eragrostis tef (Zucc.), proso millet, Panicum miliaceum L., barley, Hordeum vulgare L., and rye, Secale cereale L. Only sorghum genotypes served as hosts including Johnsongrass, Sorghum halepense (L.), a highly suitable noncrop host that generates high numbers of sugarcane aphid and maintains moderate phenotypic injury. The greenbug-resistant parental line RTx2783 that is resistant to greenbug biotypes C and E was resistant to sugarcane aphid in both greenhouse and field tests, while PI 55607 greenbug resistant to biotypes B, C, and E was highly susceptible. PI 55610 that is greenbug resistant to biotypes B, C, and E maintained moderate resistance to the sugarcane aphid, while greenbug-resistant PI 264453 was highly susceptible to sugarcane aphid. Two lines and two hybrids from the Texas A&M breeding program B11070, B11070, AB11055-WF1-CS1/RTx436, and AB11055-WF1-CS1/RTx437 were highly resistant to sugarcane aphid, as were parental types SC110, SC170, and South African lines Ent62/SADC, (Macia/TAM428)-LL9, (SV1*Sima/IS23250)-LG15. Tam428, a parental line that previously showed moderate resistance in South Africa and India, also showed moderate resistance in these evaluations. Overall, 9 of 20 parental sorghum entries tested for phenotypic damage in the field resulted in good resistance to the sugarcane aphid and should be utilized in breeding programs that develop agronomically acceptable sorghums for the southern regions of the United States. PMID:26470168

  18. Characterization of Novel Virulent Broad-Host-Range Phages of Xylella fastidiosa and Xanthomonas

    PubMed Central

    Ahern, Stephen J.; Das, Mayukh; Bhowmick, Tushar Suvra; Young, Ry

    2014-01-01

    The xylem-limited bacterium Xylella fastidiosa is the causal agent of several plant diseases, most notably Pierce's disease of grape and citrus variegated chlorosis. We report the isolation and characterization of the first virulent phages for X. fastidiosa, siphophages Sano and Salvo and podophages Prado and Paz, with a host range that includes Xanthomonas spp. Phages propagated on homologous hosts had observed adsorption rate constants of ∼4 × 10−12 ml cell−1 min−1 for X. fastidiosa strain Temecula 1 and ∼5 × 10−10 to 7 × 10−10 ml cell−1 min−1 for Xanthomonas strain EC-12. Sano and Salvo exhibit >80% nucleotide identity to each other in aligned regions and are syntenic to phage BcepNazgul. We propose that phage BcepNazgul is the founding member of a novel phage type, to which Sano and Salvo belong. The lysis genes of the Nazgul-like phage type include a gene that encodes an outer membrane lipoprotein endolysin and also spanin gene families that provide insight into the evolution of the lysis pathway for phages of Gram-negative hosts. Prado and Paz, although exhibiting no significant DNA homology to each other, are new members of the phiKMV-like phage type, based on the position of the single-subunit RNA polymerase gene. The four phages are type IV pilus dependent for infection of both X. fastidiosa and Xanthomonas. The phages may be useful as agents for an effective and environmentally responsible strategy for the control of diseases caused by X. fastidiosa. PMID:24214944

  19. Gyrodactylus proterorhini in its non-native range: distribution and ability to host-switch in freshwaters.

    PubMed

    Ondračková, Markéta

    2016-08-01

    Successful co-introduction of a parasite and its host relies not only on presence of the parasite on host individuals in the founder population but also on the ability of both host and parasite to persist in the new area. Gyrodactylus proterorhini (Monogenea) has been successfully co-introduced with its Ponto-Caspian goby hosts (Babka gymnotrachelus, Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, Proterorhinus semilunaris) to many freshwater systems in Europe and is now widely distributed over four large European river basins (Danube, Rhine, Scheldt and Vistula). Within Europe, higher infection levels are documented in sites further from the native host range. In North America, however, G. proterorhini appears to be absent. Host specificity of G. proterorhini tested under natural conditions showed accidental host-switching onto local fish species (native Perca fluviatilis and non-native Perccottus glenii) in the river Vistula. Further examination of host-switching under experimental conditions, however, showed that G. proterorhini were unable to survive on non-gobiid hosts longer than 24 h. Our results indicate extremely low potential for host-switching of introduced G. proterorhini to non-gobiid hosts, at least in the freshwater systems of Central and Western Europe. PMID:27112759

  20. Novel broad host range shuttle vectors for expression in Escherichia coli, Bacillus subtilis and Pseudomonas putida.

    PubMed

    Troeschel, Sonja Christina; Thies, Stephan; Link, Olga; Real, Catherine Isabell; Knops, Katja; Wilhelm, Susanne; Rosenau, Frank; Jaeger, Karl-Erich

    2012-10-15

    Novel shuttle vectors named pEBP were constructed to allow the gene expression in different bacterial hosts including Escherichia coli, Bacillus subtilis and Pseudomonas putida. These vectors share the inducible promoters P(T7) and P(Xyl) and a cos site to enable packaging of plasmid DNA into phage, and carry different multiple cloning sites and antibiotic resistance genes. Vector pEBP41 generally replicates episomally while pEBP18 replicates episomally in Gram-negative bacteria only, but integrates into the chromosome of B. subtilis. Plasmid copy numbers determined for E. coli and P. putida were in the range of 5-50 per cell. The functionality of pEBP18 and pEBP41 was confirmed by expression of two lipolytic enzymes, namely lipase A from B. subtilis and cutinase from the eukaryotic fungus Fusarium solani pisi in three different host strains. Additionally, we report here the construction of a T7 RNA polymerase-based expression strain of P. putida. PMID:22440389

  1. Expansion of the Known Host Range of the Microsporidium, Pseudoloma neurophilia.

    PubMed

    Sanders, Justin L; Watral, Virginia; Stidworthy, Mark F; Kent, Michael L

    2016-07-01

    The microsporidium, Pseudoloma neurophilia, is the most common infectious organism found in laboratory zebrafish colonies. Many currently used zebrafish lines originally came from pet store fish, and the initial description of P. neurophilia came from zebrafish obtained from a retail pet store. However, as P. neurophilia has not been described from wild-caught zebrafish, whether P. neurophilia is a natural pathogen of zebrafish is an open question. The pooling of fish of different species in the aquarium fish trade is common and a generalist parasite could be transmitted to novel hosts in this scenario. We determined that P. neurophilia can infect seven species of fishes from five families by cohabitation with infected zebrafish: Betta splendens, Xiphophorus maculatus, Devario aequipinnatus, Pimephales promelas, Oryzias latipes, Carassius auratus and Paracheirodon innesi. Infections in these fishes were histologically similar to those of zebrafish. We include a case report of a laboratory population of fathead minnows with naturally acquired P. neurophilia infections. With such a broad host range, including several fish families, other laboratory fishes should be screened routinely for this and other microsporidian parasites. PMID:27182659

  2. Conjugative transfer of broad host range plasmids to an acidobacterial strain, Edaphobacter aggregans.

    PubMed

    Bouhajja, Emna; Efthymiopoulos, Theocharis; George, Isabelle F; Moreels, David; Van Houdt, Rob; Mergeay, Max; Agathos, Spiros N

    2016-03-10

    The Acidobacteria phylum is of high ecological interest. Its members are ubiquitous and particularly abundant in soils but many are recalcitrant to cultivation in the laboratory. Thus, the ability of Acidobacteria to capture and maintain plasmids remains largely unexplored. In this work we tested the transfer and the stability of (i) the PromA plasmid pMOL98 and (ii) the IncQ plasmid pKT230 to the acidobacterial strain Edaphobacter aggregans DSM 19364. To this end quantitative conjugation assays were performed and transconjugants were scored for plasmid-borne antibiotic selection markers. The tested plasmids were transferred and maintained in the new host. Plasmid pMOL98 was more stable than pKT230 in Ed. aggregans in the absence of positive selection. Thus, from an ecological point of view, we have extended the host range of PromA and IncQ plasmids for the first time to an acidobacterial strain. Furthermore, we have uncovered the potential of Acidobacteria to capture as-yet-unknown plasmids and to foster the development of new cloning and expression systems for the exploitation of biotechnologically valuable soil resources. PMID:26808872

  3. Genetic diversity, host range, and distribution of tomato yellow leaf curl virus in Iran.

    PubMed

    Shirazi, M; Mozafari, J; Rakhshandehroo, F; Shams-Bakhsh, M

    2014-01-01

    Tomato yellow leaf curl virus (TYLCV) is considered one of the most important tomato pathogens in tropical and subtropical regions including Iran. During the years 2007 to 2009, a total number of 510 symptomatic and asymptomatic vegetable, ornamental and weed samples were collected from fields and greenhouses in ten provinces of Iran. Symptoms included stunting, yellowing, leaf curl and flower senescence. PCR with specific primers showed TYLCV infection in 184 samples (36%) such as cucumber, pepper, tomato and several weeds from seven provinces. Based on the geographical origin, host range and symptoms, twenty three representative isolates were selected for phylogenetic analysis. An amplicon with a size about 608 base pair (bp) comprising partial sequence of the coat (CP) and movement protein (MP) coding regions of the viral genome was sequenced and compared with the corresponding selected sequences available in GenBank for Iran and worldwide. Phylogenetic analyses on the basis of the nucleotide sequences indicated two geographically separated clades. Isolates collected from Hormozgan, Khuzestan and Kerman provinces were grouped together with other Iranian isolates including TYLCV-Ir2, TYLCV-Kahnooj, and an isolate from Oman. It was also revealed that isolates collected from Boushehr, Fars, Tehran, and Isfahan placed close to the Iranian isolate TYLCV-Abadeh and isolates from Israel and Egypt. No correlation was found between the genetic variation and the host species, but selected Iranian isolates were grouped on the basis of the geographical origins. Results of this study indicated a high genetic diversity among Iranian TYLCV isolates. PMID:24957717

  4. Prevalence, host range, and spatial distribution of black band disease in the Maldivian Archipelago.

    PubMed

    Montano, Simone; Strona, Giovanni; Seveso, Davide; Galli, Paolo

    2013-07-01

    Little research has been conducted on diseases affecting reef-building corals in the central Indian Ocean. During 2010 and 2011, we performed a quantitative assessment of black band disease (BBD) in the central Republic of Maldives. Distribution, host range, and prevalence of BBD were investigated at 6 coral islands (Magoodhoo, Adanga, Ihuru, Vabbinfaru, Thudufushi, and Athuruga) belonging to 3 different atolls. BBD was found to be widespread among the atolls. All the islands showed a prevalence lower than 0.5%. Magoodhoo Island showed the highest mean disease prevalence. In the whole surveyed area, shallow sites showed higher overall mean BBD prevalence than deep ones. BBD was recorded from 6 scleractinian families (Acroporidae, Faviidae, Poritidae, Siderastreidae, Agariciidae, Fungiidae) and 13 scleractinian genera. Two of them, Gardineroseris and Sandalolitha, constitute new records for the disease. The siderastreid Psammocora (BBD prevalence: 5.33 ± 1.41%, mean ± SE) was the most affected genus, followed by Goniopora (2.7 ± 1.3%). BBD prevalence was positively correlated to the respective host density in both genera. Favites and Acropora were the less affected genera (both <0.1%). Although we observed an extremely low overall disease prevalence in the surveyed area (<1%), the large number of different scleractinian genera affected and the widespread distribution of BBD indicate a need for further investigation. PMID:23836771

  5. Canine and feline host ranges of canine parvovirus and feline panleukopenia virus: distinct host cell tropisms of each virus in vitro and in vivo.

    PubMed Central

    Truyen, U; Parrish, C R

    1992-01-01

    Canine parvovirus (CPV) emerged as an apparently new virus during the mid-1970s. The origin of CPV is unknown, but a variation from feline panleukopenia virus (FPV) or another closely related parvovirus is suspected. Here we examine the in vitro and in vivo canine and feline host ranges of CPV and FPV. Examination of three canine and six feline cell lines and mitogen-stimulated canine and feline peripheral blood lymphocytes revealed that CPV replicates in both canine and feline cells, whereas FPV replicates efficiently only in feline cells. The in vivo host ranges were unexpectedly complex and distinct from the in vitro host ranges. Inoculation of dogs with FPV revealed efficient replication in the thymus and, to some degree, in the bone marrow, as shown by virus isolation, viral DNA recovery, and Southern blotting and by strand-specific in situ hybridization. FPV replication could not be demonstrated in mesenteric lymph nodes or in the small intestine, which are important target tissues in CPV infection. Although CPV replicated well in all the feline cells tested in vitro, it did not replicate in any tissue of cats after intramuscular or intravenous inoculation. These results indicate that these viruses have complex and overlapping host ranges and that distinct tissue tropisms exist in the homologous and heterologous hosts. Images PMID:1323703

  6. Host range, growth property, and virulence of the smallpox vaccine: Vaccinia virus Tian Tan strain

    SciTech Connect

    Fang Qing; Yang Lin; Zhu Weijun; Liu Li; Wang Haibo; Yu Wenbo; Xiao Genfu; Tien Po; Zhang Linqi; Chen Zhiwei . E-mail: zchen@adarc.org

    2005-05-10

    Vaccinia Tian Tan (VTT) was used as a vaccine against smallpox in China for millions of people before 1980, yet the biological characteristics of the virus remain unclear. We have characterized VTT with respect to its host cell range, growth properties in vitro, and virulence in vivo. We found that 11 of the 12 mammalian cell lines studied are permissive to VTT infection whereas one, CHO-K1, is non-permissive. Using electron microscopy and sequence analysis, we found that the restriction of VTT replication in CHO-K1 is at a step before viral maturation probably due to the loss of the V025 gene. Moreover, VTT is significantly less virulent than vaccinia WR but remains neurovirulent in mice and causes significant body weight loss after intranasal inoculation. Our data demonstrate the need for further attenuation of VTT to serve either as a safer smallpox vaccine or as a live vaccine vector for other pathogens.

  7. In vitro and in vivo host range of Anopheles gambiae densovirus (AgDNV)

    PubMed Central

    Suzuki, Yasutsugu; Barik, Tapan K.; Johnson, Rebecca M.; Rasgon, Jason L.

    2015-01-01

    AgDNV is a powerful gene transduction tool and potential biological control agent for Anopheles mosquitoes. Using a GFP reporter virus system, we investigated AgDNV host range specificity in four arthropod cell lines (derived from An. gambiae, Aedes albopictus and Drosophila melanogaster) and six mosquito species from 3 genera (An. gambiae, An. arabiensis, An. stephensi, Ae. albopictus, Ae. aegypti and Culex tarsalis). In vitro, efficient viral invasion, replication and GFP expression was only observed in MOS55 An. gambiae cells. In vivo, high levels of GFP were observed in An. gambiae mosquitoes. Intermediate levels of GFP were observed in the closely related species An. arabiensis. Low levels of GFP were observed in An. stephensi, Ae. albopictus, Ae. aegypti and Cx. tarsalis. These results suggest that AgDNV is a specific gene transduction tool for members of the An. gambiae species complex, and could be potentially developed into a biocontrol agent with minimal off-target effects. PMID:26220140

  8. Global displacement of canine parvovirus by a host-adapted variant: structural comparison between pandemic viruses with distinct host ranges.

    PubMed

    Organtini, Lindsey J; Allison, Andrew B; Lukk, Tiit; Parrish, Colin R; Hafenstein, Susan

    2015-02-01

    Canine parvovirus type 2 (CPV-2) emerged in 1978 and spread worldwide within 2 years. Subsequently, CPV-2 was completely replaced by the variant CPV-2a, which is characterized by four specific capsid (VP2) mutations. The X-ray crystal structure of the CPV-2a capsid shows that each mutation confers small local changes. The loss of a hydrogen bond and introduction of a glycine residue likely introduce flexibility to sites that control interactions with the host receptor, antibodies, and sialic acids. PMID:25410876

  9. Insulin signaling pathways in lepidopteran ecdysone secretion

    PubMed Central

    Smith, Wendy A.; Lamattina, Anthony; Collins, McKensie

    2014-01-01

    Molting and metamorphosis are stimulated by the secretion of ecdysteroid hormones from the prothoracic glands. Insulin-like hormones have been found to enhance prothoracic gland activity, providing a mechanism to link molting to nutritional state. In silk moths (Bombyx mori), the prothoracic glands are directly stimulated by insulin and the insulin-like hormone bombyxin. Further, in Bombyx, the neuropeptide prothoracicotropic hormone (PTTH) appears to act at least in part through the insulin-signaling pathway. In the prothoracic glands of Manduca sexta, while insulin stimulates the phosphorylation of the insulin receptor and Akt, neither insulin nor bombyxin II stimulate ecdysone secretion. Involvement of the insulin-signaling pathway in Manduca prothoracic glands was explored using two inhibitors of phosphatidylinositol-3-kinase (PI3K), LY294002 and wortmannin. PI3K inhibitors block the phosphorylation of Akt and 4EBP but have no effect on ecdysone secretion, or on the phosphorylation of the MAPkinase, ERK. Inhibitors that block phosphorylation of ERK, including the MEK inhibitor U0126, and high doses of the RSK inhibitor SL0101, effectively inhibit ecdysone secretion. The results highlight differences between the two lepidopteran insects most commonly used to directly study ecdysteroid secretion. In Bombyx, the PTTH and insulin-signaling pathways intersect; both insulin and PTTH enhance the phosphorylation of Akt and stimulate ecdysteroid secretion, and inhibition of PI3K reduces ecdysteroid secretion. By contrast, in Manduca, the action of PTTH is distinct from insulin. The results highlight species differences in the roles of translational regulators such as 4EBP, and members of the MAPkinase pathway such as ERK and RSK, in the regulation of insect ecdysone secretion, and in the impact of nutritionally-sensitive hormones such as insulin in the control of ecdysone secretion and molting. PMID:24550835

  10. Characterization of a new iridovirus isolated from crickets and investigations on the host range

    PubMed

    Kleespies; Tidona; Darai

    1999-01-01

    Typical signs of an iridovirus infection were observed in two species of fatally diseased crickets, Gryllus campestris L. and Acheta domesticus L. (Orthoptera, Gryllidae). The infection was manifested by hypertrophy and bluish iridescence of the affected fat body cells. Electron microscope investigations led to the identification of a new iridovirus, which was termed cricket iridovirus (CrIV). In negatively stained preparations the size of the icosahedral virus particles ranged from 151 nm (side-side) to 167 nm (apex-apex). Assembly of virions occurred in the cytoplasm of hypertrophied fat body cells, where they often accumulated in paracrystalline arrays. Genetic analyses of purified viral DNA using a variety of restriction enzymes revealed that CrIV is distinct from all other known iridoviruses that have been isolated from insects and reported so far. In host range studies it was shown that CrIV can be transmitted perorally to other orthopteran species, causing characteristic symptoms and fatal disease. These species include Gryllus bimaculatus L. (Orthoptera, Gryllidae) and the African migratory locust Locusta migratoria migratorioides (R. & F.) (Orthoptera, Acrididae), which represents one of the most important pest insects in developing countries, as well as the cockroaches Blattella germanica L. and Blatta orientalis L. (both Orthoptera, Blattidae). Consequently, the isolation and characterization of this new cricket iridovirus is of particular interest in view of its possible use in biological or integrated control. Copyright 1999 Academic Press. PMID:9878293

  11. Impact of Bt maize pollen (MON810) on lepidopteran larvae living on accompanying weeds.

    PubMed

    Gathmann, Achim; Wirooks, Ludger; Hothorn, Ludwig A; Bartsch, Detlef; Schuphan, Ingolf

    2006-08-01

    Environmental risks of Bt maize, particularly pollen drift from Bt maize, were assessed for nontarget lepidopteran larvae in maize field margins. In our experimental approach, we carried out 3-year field trials on 6 ha total. Three treatments were used in a randomized block design with eight replications resulting in 24 plots: (i) near-isogenic control variety without insecticide (control), (ii) near-isogenic control variety with chemical insecticide (Baytroid) and (iii) Bt maize expressing the recombinant toxin. We established a weed strip (20 x 1 m) in every plot consisting of a Chenopodium album (goosefoot)/Sinapis alba (mustard) mixture. In these strips we measured diversity and abundance of lepidopteran larvae during maize bloom and pollen shed. C. album hosted five species but all in very low densities; therefore data were not suitable for statistical analysis. S. alba hosted nine species in total. Most abundant were Plutella xylostella and Pieris rapae. For these species no differences were detected between the Bt treatment and the control, but the chemical insecticide treatment reduced larval abundance significantly. Conclusions regarding experimental methodology and results are discussed in regard to environmental risk assessment and monitoring of genetically modified organisms. PMID:16842436

  12. SPODOBASE : an EST database for the lepidopteran crop pest Spodoptera

    PubMed Central

    Nègre, Vincent; Hôtelier, Thierry; Volkoff, Anne-Nathalie; Gimenez, Sylvie; Cousserans, François; Mita, Kazuei; Sabau, Xavier; Rocher, Janick; López-Ferber, Miguel; d'Alençon, Emmanuelle; Audant, Pascaline; Sabourault, Cécile; Bidegainberry, Vincent; Hilliou, Frédérique; Fournier, Philippe

    2006-01-01

    Background The Lepidoptera Spodoptera frugiperda is a pest which causes widespread economic damage on a variety of crop plants. It is also well known through its famous Sf9 cell line which is used for numerous heterologous protein productions. Species of the Spodoptera genus are used as model for pesticide resistance and to study virus host interactions. A genomic approach is now a critical step for further new developments in biology and pathology of these insects, and the results of ESTs sequencing efforts need to be structured into databases providing an integrated set of tools and informations. Description The ESTs from five independent cDNA libraries, prepared from three different S. frugiperda tissues (hemocytes, midgut and fat body) and from the Sf9 cell line, are deposited in the database. These tissues were chosen because of their importance in biological processes such as immune response, development and plant/insect interaction. So far, the SPODOBASE contains 29,325 ESTs, which are cleaned and clustered into non-redundant sets (2294 clusters and 6103 singletons). The SPODOBASE is constructed in such a way that other ESTs from S. frugiperda or other species may be added. User can retrieve information using text searches, pre-formatted queries, query assistant or blast searches. Annotation is provided against NCBI, UNIPROT or Bombyx mori ESTs databases, and with GO-Slim vocabulary. Conclusion The SPODOBASE database provides integrated access to expressed sequence tags (EST) from the lepidopteran insect Spodoptera frugiperda. It is a publicly available structured database with insect pest sequences which will allow identification of a number of genes and comprehensive cloning of gene families of interest for scientific community. SPODOBASE is available from URL: PMID:16796757

  13. Comparison of ranging behaviour in a multi-species complex of free-ranging hosts of bovine tuberculosis in relation to their use as disease sentinels.

    PubMed

    Yockney, I J; Nugent, G; Latham, M C; Perry, M; Cross, M L; Byrom, A E

    2013-07-01

    Sentinel species are increasingly used by disease managers to detect and monitor the prevalence of zoonotic diseases in wildlife populations. Characterizing home-range movements of sentinel hosts is thus important for developing improved disease surveillance methods, especially in systems where multiple host species co-exist. We studied ranging activity of major hosts of bovine tuberculosis (TB) in an upland habitat of New Zealand: we compared home-range coverage by ferrets (Mustela furo), wild deer (Cervus elaphus), feral pigs (Sus scrofa), brushtail possums (Trichosurus vulpecula) and free-ranging farmed cattle (Bos taurus). We also report in detail the proportional utilization of a seasonal (4-monthly) range area for the latter four species. Possums covered the smallest home range (<30 ha), ferrets covered ~100 ha, pigs ~4 km(2), deer and cattle both >30 km2. For any given weekly period, cattle, deer and pigs were shown to utilize 37–45% of their estimated 4-month range, while possums utilized 62% during any weekly period and 85% during any monthly period of their estimated 4-month range. We suggest that present means for estimating TB detection kernels, based on long-term range size estimates for possums and sentinel species, probably overstate the true local surveillance coverage per individual. PMID:23433406

  14. Structure Function Studies of Vaccinia Virus Host Range Protein K1 Reveal a Novel Functional Surface for Ankyrin Repeat Proteins▿

    PubMed Central

    Li, Yongchao; Meng, Xiangzhi; Xiang, Yan; Deng, Junpeng

    2010-01-01

    Poxvirus host tropism at the cellular level is regulated by virus-encoded host range proteins acting downstream of virus entry. The functioning mechanisms of most host range proteins are unclear, but many contain multiple ankyrin (ANK) repeats, a motif that is known for ligand interaction through a concave surface. We report here the crystal structure of one of the ANK repeat-containing host range proteins, the vaccinia virus K1 protein. The structure, at a resolution of 2.3 Å, showed that K1 consists entirely of ANK repeats, including seven complete ones and two incomplete ones, one each at the N and C terminus. Interestingly, Phe82 and Ser83, which were previously shown to be critical for K1's function, are solvent exposed and located on a convex surface, opposite the consensus ANK interaction surface. The importance of this convex surface was further supported by our additional mutagenesis studies. We found that K1's host range function was negatively affected by substitution of either Asn51 or Cys47 and completely abolished by substitution of both residues. Cys47 and Asn51 are also exposed on the convex surface, spatially adjacent to Phe82 and Ser83. Altogether, our data showed that K1 residues on a continuous convex ANK repeat surface are critical for the host range function, suggesting that K1 functions through ligand interaction and does so with a novel ANK interaction surface. PMID:20089642

  15. Structure Function Studies of Vaccinia Virus Host Range Protein K1 Reveal a Novel Functional Surface for Ankyrin Repeat Proteins

    SciTech Connect

    Li, Yongchao; Meng, Xiangzhi; Xiang, Yan; Deng, Junpeng

    2010-06-15

    Poxvirus host tropism at the cellular level is regulated by virus-encoded host range proteins acting downstream of virus entry. The functioning mechanisms of most host range proteins are unclear, but many contain multiple ankyrin (ANK) repeats, a motif that is known for ligand interaction through a concave surface. We report here the crystal structure of one of the ANK repeat-containing host range proteins, the vaccinia virus K1 protein. The structure, at a resolution of 2.3 {angstrom}, showed that K1 consists entirely of ANK repeats, including seven complete ones and two incomplete ones, one each at the N and C terminus. Interestingly, Phe82 and Ser83, which were previously shown to be critical for K1's function, are solvent exposed and located on a convex surface, opposite the consensus ANK interaction surface. The importance of this convex surface was further supported by our additional mutagenesis studies. We found that K1's host range function was negatively affected by substitution of either Asn51 or Cys47 and completely abolished by substitution of both residues. Cys47 and Asn51 are also exposed on the convex surface, spatially adjacent to Phe82 and Ser83. Altogether, our data showed that K1 residues on a continuous convex ANK repeat surface are critical for the host range function, suggesting that K1 functions through ligand interaction and does so with a novel ANK interaction surface.

  16. Species Boundaries and Host Range of Tortoise Mites (Uropodoidea) Phoretic on Bark Beetles (Scolytinae), Using Morphometric and Molecular Markers

    PubMed Central

    Knee, Wayne; Beaulieu, Frédéric; Skevington, Jeffrey H.; Kelso, Scott; Cognato, Anthony I.; Forbes, Mark R.

    2012-01-01

    Understanding the ecology and evolutionary history of symbionts and their hosts requires accurate taxonomic knowledge, including clear species boundaries and phylogenies. Tortoise mites (Mesostigmata: Uropodoidea) are among the most diverse arthropod associates of bark beetles (Curculionidae: Scolytinae), but their taxonomy and host associations are largely unstudied. We tested the hypotheses that (1) morphologically defined species are supported by molecular data, and that (2) bark beetle uropodoids with a broad host range comprise cryptic species. To do so, we assessed the species boundaries of uropodoid mites collected from 51 host species, across 11 countries and 103 sites, using morphometric data as well as partial cytochrome oxidase I (COI) and nuclear large subunit ribosomal DNA (28S). Overall, morphologically defined species were confirmed by molecular datasets, with a few exceptions. Twenty-nine of the 36 uropodoid species (Trichouropoda, Nenteria and Uroobovella) collected in this study had narrow host ranges, while seven species had putative broad host ranges. In all but one species, U. orri, our data supported the existence of these host generalists, which contrasts with the typical finding that widespread generalists are actually complexes of cryptic specialists. PMID:23071768

  17. Seasonal Alterations in Host Range and Fidelity in the Polyphagous Mirid Bug, Apolygus lucorum (Heteroptera: Miridae)

    PubMed Central

    Pan, Hongsheng; Liu, Bing; Lu, Yanhui; Wyckhuys, Kris A. G.

    2015-01-01

    In herbivorous insects, host plant switching is commonly observed and plays an important role in their annual life cycle. However, much remains to be learned about seasonal host switching of various pestiferous arthropods under natural conditions. From 2006 until 2012, we assessed Apolygus lucorum (Meyer-Dür) host plant use in successive spring, summer and winter seasons at one single location (Langfang, China). Data were used to quantify changes in host plant breadth and host fidelity between seasons. Host fidelity of A. lucorum differed between seasons, with 87.9% of spring hosts also used in the summer and 36.1% of summer hosts used in winter. In contrast, as little as 25.6% host plant species were shared between winter and spring. Annual herbaceous plants are most often used for overwintering, while perennial woody plants are relatively important for initial population build-up in the spring. Our study contributes to an improved understanding of evolutionary interactions between A. lucorum and its host plants and lays the groundwork for the design of population management strategies for this important pest in myriad crops. PMID:25692969

  18. Host range and community structure of avian nest parasites in the genus Philornis (Diptera: Muscidae) on the island of Trinidad

    PubMed Central

    Bulgarella, Mariana; Heimpel, George E

    2015-01-01

    Parasite host range can be influenced by physiological, behavioral, and ecological factors. Combining data sets on host–parasite associations with phylogenetic information of the hosts and the parasites involved can generate evolutionary hypotheses about the selective forces shaping host range. Here, we analyzed associations between the nest-parasitic flies in the genus Philornis and their host birds on Trinidad. Four of ten Philornis species were only reared from one species of bird. Of the parasite species with more than one host bird species, P. falsificus was the least specific and P. deceptivus the most specific attacking only Passeriformes. Philornis flies in Trinidad thus include both specialists and generalists, with varying degrees of specificity within the generalists. We used three quantities to more formally compare the host range of Philornis flies: the number of bird species attacked by each species of Philornis, a phylogenetically informed host specificity index (Poulin and Mouillot's STD), and a branch length-based STD. We then assessed the phylogenetic signal of these measures of host range for 29 bird species. None of these measures showed significant phylogenetic signal, suggesting that clades of Philornis did not differ significantly in their ability to exploit hosts. We also calculated two quantities of parasite species load for the birds – the parasite species richness, and a variant of the STD index based on nodes rather than on taxonomic levels – and assessed the signal of these measures on the bird phylogeny. We did not find significant phylogenetic signal for the parasite species load or the node-based STD index. Finally, we calculated the parasite associations for all bird pairs using the Jaccard index and regressed these similarity values against the number of nodes in the phylogeny separating bird pairs. This analysis showed that Philornis on Trinidad tend to feed on closely related bird species more often than expected by

  19. Broad-Host Range Vector-Particle: Gene Transfer Particles From Thermal Vents

    NASA Astrophysics Data System (ADS)

    Chiura, H. X.; Nakamura, K.; Fukazawa, Y.; Nakata, D.; Tomaru, A.; Okita, N.; Hoaki, T.

    2002-12-01

    Viruses or virus-like particles (VLPs) are common in aquatic ecosystems, however, VLP-host interactions and its commitments to gene transfer in the environment is yet unclear. We have proposed that at least some of the widely distributed VLPs could be general gene transfer agents among a wide range of microbial host cells, and might function as a universal vector (1-4). To elucidate such a broad host range gene transfer mediated by "VLP", the sampling site was extended to the hyper hydrothermal vent, and boring cores. VLP (v) and cell (b) abundances per ml water samples from drilling holes of Suiyo seamount were: APSK04 (28°34.303'N, 140°38.618'E, 1385 m deep, 21°C, b = 8.26 *E^{6}, v = 6.03 x 10^{6}); APSK07 (28°34.299'N, 140°38.690'E, 1386 m deep, 250.5°C, b = 5.33 \\times 104, v = 2.52 \\times 104); a natural vent near APSK05 (28°34.322'N, 140°38.594'E, 1382 m deep, 304.7°C, b = 3.23 x 10^{4}, v = 1.85 x 10^{4}). A boring core sample was obtained from APSK06 (28°34.313'N, 140°38.617', 1386 m deep), from which a hyper thermophilic Archaean, Thermococcus kodakaraensis was successfully cultivated in sulphur supplemented medium between 70 and 90°C. VLP production was observed from T. kodakaraensis, whose VLP (v) and cell (b) abundances per ml at 480 h culture at 70°C were: b = 3.61 *E^{9}, v = 3.46 *E^{9}. Transduction experiment at multiplicity of infection of ca 0.2 using particles from APSK07 and T. kodakaraensis showed a plate efficiency on recipient Escherichia coli AB1157 by ca 72 % and ca 89 % regardless of UV treatment of the particle. Gene transfer frequency of APSK07 particle was (x 10^{-5} cfu/particle) between 2.4 and 0.92, and that of T. kodakaraensis particle was between x 10^{-4} and x 10^{-5}$ cfu/particle. These findings suggest the non-specific gene transfer by such particles may be a ubiquitous event in the natural environment. Such gene transfer particles may have mediated gene flux among phylogenetically diverse microbial

  20. The Role of Flavonoids in Nodulation Host-Range Specificity: An Update.

    PubMed

    Liu, Cheng-Wu; Murray, Jeremy D

    2016-01-01

    Flavonoids are crucial signaling molecules in the symbiosis between legumes and their nitrogen-fixing symbionts, the rhizobia. The primary function of flavonoids in the interaction is to induce transcription of the genes for biosynthesis of the rhizobial signaling molecules called Nod factors, which are perceived by the plant to allow symbiotic infection of the root. Many legumes produce specific flavonoids that only induce Nod factor production in homologous rhizobia, and therefore act as important determinants of host range. Despite a wealth of evidence on legume flavonoids, relatively few have proven roles in rhizobial infection. Recent studies suggest that production of key "infection" flavonoids is highly localized at infection sites. Furthermore, some of the flavonoids being produced at infection sites are phytoalexins and may have a role in the selection of compatible symbionts during infection. The molecular details of how flavonoid production in plants is regulated during nodulation have not yet been clarified, but nitrogen availability has been shown to play a role. PMID:27529286

  1. Expansion of Viral Host Range through Complementation and Recombination in Transgenic Plants.

    PubMed Central

    Schoelz, JE; Wintermantel, WM

    1993-01-01

    We have shown previously that gene VI of cauliflower mosaic virus (CaMV) strain D4 governs systemic infection of Nicotiana bigelovii and that transgenic N. bigelovii expressing the D4 gene VI product can complement at least one CaMV isolate for long-distance transport. We have now found that DNA of two other isolates of CaMV recombine with the gene VI coding sequence present in the transgenic plants. The formation of recombinant viruses occurs as a consequence of CaMV replication, involving two template switches during reverse transcription of the CaMV RNA to DNA. The first template switch occurs at the 5[prime] end of the 35S RNA to the gene VI mRNA produced by the transgenic plants. A second switch occurs at the 5[prime] end of the gene VI mRNA back to the 35S RNA. We also demonstrate that CaMV can acquire sequences from transgenic plants that alter the symptomatology and host range of the virus, an observation that may have important risk assessment implications for strategies using pathogen-derived resistance to protect plants against virus diseases. PMID:12271051

  2. Generation of high-titer pseudotyped retroviral vectors with very broad host range.

    PubMed

    Yee, J K; Friedmann, T; Burns, J C

    1994-01-01

    Encapsidation of the VSV G protein into the virions of MoMLV-derived retroviral vectors in the absence of other VSV-encoded proteins is shown to be an efficient process, although the exact mechanism for this process is currently unclear. Unlike the conventional retroviral vectors bearing the amphotropic envelope protein, the pseudotyped virus has the ability to withstand the shearing forces encountered during ultracentrifugation. This property of the pseudotyped virus enables the generation of high-titer retroviral vector stocks and has potential application for in vivo gene therapy studies. We have found as many as four copies of a pseudotyped vector to integrate into the genome of a single cell when a high multiplicity of infection was used to infect the cells. Multiple integration events were not observed with amphotropic retroviral vectors, probably because of their low virus titers. In addition, when retroviral vectors are pseudotyped with the VSV G protein, they acquire the host range of VSV and are able to infect nonmammalian cells derived from fish, Xenopus, mosquito, and Lepidoptera. Since techniques for efficient gene transfer in some of these nonmammalian systems are not currently available, retrovirus-mediated gene transfer described here should be useful for transgenic and other genetic studies in lower vertebrate species. The inability to establish a stable cell line expressing the VSV G protein, however, limits large-scale production of the pseudotyped retroviral vectors. Generation of stable packaging cell lines for the pseudotyped retroviral vectors is a major challenge for the future. PMID:7823872

  3. The avian and mammalian host range of highly pathogenic avian H5N1 influenza

    PubMed Central

    Kaplan, Bryan S.; Webby, Richard J.

    2013-01-01

    Highly pathogenic H5N1 influenza viruses have been isolated from a number of avian and mammalian species. Despite intensive control measures the number of human and animal cases continues to increase. A more complete understanding of susceptible species and of contributing environmental and molecular factors is crucial if we are to slow the rate of new cases. H5N1 is currently endemic in domestic poultry in only a handful of countries with sporadic and unpredictable spread to other countries. Close contact of terrestrial bird or mammalian species with infected poultry/waterfowl or their biological products is the major route for interspecies transmission. Intra-species transmission of H5N1 in mammals, including humans, has taken place on a limited scale though it remains to be seen if this will change; recent laboratory studies suggest that it is indeed possible. Here we review the avian and mammalian species that are naturally susceptible to H5N1 infection and the molecular factors associated with its expanded host range. PMID:24025480

  4. Genetic diversity and host range studies of turnip curly top virus.

    PubMed

    Razavinejad, Sara; Heydarnejad, Jahangir; Kamali, Mehdi; Massumi, Hossain; Kraberger, Simona; Varsani, Arvind

    2013-04-01

    Turnip curly top virus (TCTV) is a unique geminivirus that has recently been characterised as infecting turnips in Iran. The genome of TCTV shares <68 % pairwise identity with other geminiviruses and has a genome organisation similar to that of curtoviruses and topocuvirus. The replication-associated protein (Rep) bears the highest similarity to curtovirus Reps (48.5-69.0 %); however, in the case of the capsid protein (CP), the extent of similarity is only 39.5-44.5 %. We constructed an agroinfectious clone of TCTV and undertook host range studies on ten plant species; in three species (turnip, sugar beet and cowpea), we detected infection which presents curly top symptoms in turnip and sugar beet. The efficiency of TCTV infection in agroinoculated turnip plants was 71.7 %, and the infection was successfully transmitted to 80 % of the healthy turnip plants used in the insect transmission studies by Circulifer haematoceps under greenhouse conditions. We also determined the genome sequence of 14 new TCTV isolates from southern Iran isolated from turnips. We observed ~13 % diversity amongst all the TCTV isolates and found evidence of recombination in the CP- and Rep-coding regions of the genomes. PMID:23225113

  5. Tree host range and world distribution of the extomycorrhizal fungus Pisolithus tinctorius.

    PubMed

    Marx, D H

    1977-03-01

    The natural occurrence of Pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the United States. This ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. Experiments have proved that this fungal symbiont forms ectomycorrhizae with Abies procera, Betula pendula, Carya illnoensis, 11 species of Eucalyptus, 30 species of Pinus, Pseudotsuga menziesii var. meniziesii, 2 species of Quercus, and Tsuga heterophylla. Pisolithus has also been reported growing under natural conditions in association with three additional species of Betula, two species of Eucalyptus, nine species of Pinus, and eight species of Quercus, Populus tremuloides, Pseudotsuga grandidenta, and Salix humilis. This fungal symbiont has great potential in forestation efforts because of (1) the availability of practical techniques for artificially introducing in into nursery soils; (2) its ability to improve tree survival and growth in the nursery and the field; (3) its near worldwide distribution on a variety of sites; and (4) its broad host range encompassing many of the world's most important tree species. PMID:856419

  6. Avian host range of Chlamydophila spp. based on isolation, antigen detection and serology.

    PubMed

    Kaleta, E F; Taday, Eva M A

    2003-10-01

    Published reports and our own diagnostic data on the avian host range of avian Chlamydophila spp. are presented in an attempt to provide evidence for the large number of bird species that have been naturally infected with chlamydia. The term 'chlamydia-positive' is based on either isolation of the organism and antigen detection or on serological detection of circulating antibodies. The list of chlamydia-positive birds contains the six major domestic species (chicken, turkey, Pekin duck, Muscovy duck, goose, and pigeon), the three minor domestic species (Japanese quail, bobwhite quail, and peafowl) and a total of 460 free-living or pet bird species in 30 orders. The order Psittaciformes contains by far the most (153 of 342; 45%) chlamydia-positive bird species. More than 20% of all species per order are positive for chlamydia in the orders Lariformes (gulls, 26 of 92 species; 28%), Alciformes (alks, six of 23 species; 26%), Sphenisciformes (penguins, four of 16 species; 25%), and Anseriformes (ducks and geese, 33 of 157 species; 21%). Only 5% of all bird species (14 of 259 species) in the order Phasianiformes (gallinaceus birds) are chlamydia-positive. The different percentages of chlamydia-positive bird species reflect: (i) a high rate of investigations (e.g. of domestic birds) compared with infrequent testing (e.g. of Charadriiformes or Cuculiformes), (ii) frequent zoonotic implications (e.g. psittacine and columbiform birds), and (iii) an assumed high susceptibility to infection and subsequent seroconversion (e.g. waterfowl). PMID:14522700

  7. A T3 and T7 recombinant phage acquires efficient adsorption and a broader host range.

    PubMed

    Lin, Tiao-Yin; Lo, Yi-Haw; Tseng, Pin-Wei; Chang, Shun-Fu; Lin, Yann-Tsyr; Chen, Ton-Seng

    2012-01-01

    It is usually thought that bacteriophage T7 is female specific, while phage T3 can propagate on male and female Escherichia coli. We found that the growth patterns of phages T7M and T3 do not match the above characteristics, instead showing strain dependent male exclusion. Furthermore, a T3/7 hybrid phage exhibits a broader host range relative to that of T3, T7, as well as T7M, and is able to overcome the male exclusion. The T7M sequence closely resembles that of T3. T3/7 is essentially T3 based, but a DNA fragment containing part of the tail fiber gene 17 is replaced by the T7 sequence. T3 displays inferior adsorption to strains tested herein compared to T7. The T3 and T7 recombinant phage carries altered tail fibers and acquires better adsorption efficiency than T3. How phages T3 and T7 recombine was previously unclear. This study is the first to show that recombination can occur accurately within only 8 base-pair homology, where four-way junction structures are identified. Genomic recombination models based on endonuclease I cleavages at equivalent and nonequivalent sites followed by strand annealing are proposed. Retention of pseudo-palindromes can increase recombination frequency for reviving under stress. PMID:22347414

  8. African Swine Fever Virus Multigene Family 360 and 530 Genes Are Novel Macrophage Host Range Determinants

    PubMed Central

    Zsak, L.; Lu, Z.; Burrage, T. G.; Neilan, J. G.; Kutish, G. F.; Moore, D. M.; Rock, D. L.

    2001-01-01

    Pathogenic African swine fever virus (ASFV) isolates primarily target cells of the mononuclear-phagocytic system in infected swine and replicate efficiently in primary macrophage cell cultures in vitro. ASFVs can, however, be adapted to grow in monkey cell lines. Characterization of two cell culture-adapted viruses, MS16 and BA71V, revealed that neither virus replicated in macrophage cell cultures. Cell viability experiments and ultrastructural analysis showed that infection with these viruses resulted in early macrophage cell death, which occurred prior to viral progeny production. Genomic cosmid clones from pathogenic ASFV isolate E70 were used in marker rescue experiments to identify sequences capable of restoring MS16 and BA71V growth in macrophage cell cultures. A cosmid clone representing a 38-kbp region at the left terminus of the genome completely restored the growth of both viruses. In subsequent fine-mapping experiments, an 11-kbp subclone from this region was sufficient for complete rescue of BA71V growth. Sequence analysis indicated that both MS16 and BA71V had significant deletions in the region containing members of multigene family 360 (MGF 360) and MGF530. Deletion of this same region from highly pathogenic ASFV isolate Pr4 significantly reduced viral growth in macrophage cell cultures. These findings indicate that ASFV MGF360 and MGF530 genes perform an essential macrophage host range function(s) that involves promotion of infected-cell survival. PMID:11238833

  9. African swine fever virus multigene family 360 and 530 genes are novel macrophage host range determinants.

    PubMed

    Zsak, L; Lu, Z; Burrage, T G; Neilan, J G; Kutish, G F; Moore, D M; Rock, D L

    2001-04-01

    Pathogenic African swine fever virus (ASFV) isolates primarily target cells of the mononuclear-phagocytic system in infected swine and replicate efficiently in primary macrophage cell cultures in vitro. ASFVs can, however, be adapted to grow in monkey cell lines. Characterization of two cell culture-adapted viruses, MS16 and BA71V, revealed that neither virus replicated in macrophage cell cultures. Cell viability experiments and ultrastructural analysis showed that infection with these viruses resulted in early macrophage cell death, which occurred prior to viral progeny production. Genomic cosmid clones from pathogenic ASFV isolate E70 were used in marker rescue experiments to identify sequences capable of restoring MS16 and BA71V growth in macrophage cell cultures. A cosmid clone representing a 38-kbp region at the left terminus of the genome completely restored the growth of both viruses. In subsequent fine-mapping experiments, an 11-kbp subclone from this region was sufficient for complete rescue of BA71V growth. Sequence analysis indicated that both MS16 and BA71V had significant deletions in the region containing members of multigene family 360 (MGF 360) and MGF530. Deletion of this same region from highly pathogenic ASFV isolate Pr4 significantly reduced viral growth in macrophage cell cultures. These findings indicate that ASFV MGF360 and MGF530 genes perform an essential macrophage host range function(s) that involves promotion of infected-cell survival. PMID:11238833

  10. Host and geographic range extensions of the North American strain of viral hemorrhagic septicemia virus

    USGS Publications Warehouse

    Hedrick, R.P.; Batts, W.N.; Yun, S.; Traxler, G.S.; Kaufman, J.; Winton, J.R.

    2003-01-01

    Viral hemorrhagic septicemia virus (VHSV) was isolated from populations of Pacific sardine Sardinops sagaxfrom the coastal waters of Vancouver Island, British Columbia, Canada, and central and southern California, USA. The virus was also isolated from Pacific mackerel Scomber japonicus in southern California, from eulachon or smeltThaleichthys pacificus, and surf smelt Hypomesus pretiosus pretiosus from Oregon, USA. Mortality and skin lesions typical of viral hemorrhagic septicemia in other marine fish species were observed among sardine in Canada and in a few surf smelt from Oregon, but the remaining isolates of VHSV were obtained from healthy appearing fish. The prevalence of VHSV among groups of apparently healthy sardine, mackerel and smelt ranged from 4 to 8% in California and Oregon. A greater prevalence of infection (58%) occurred in groups of sardine sampled in Canada that sustained a naturally occurring epidemic during 1998-99. A captive group of surf smelt in Oregon exhibited an 81% prevalence of infection with clinical signs in only a few fish. The new isolates were confirmed as North American VHSV and were closely related based on comparisons of the partial nucleotide sequence of the glycoprotein (G) gene. The VHSV isolates from sardine in Canada and California were the most closely related, differing from isolates obtained from other marine fish species and salmonids in British Columbia, Canada, Alaska and Washington, USA. These new virus isolations extend both the known hosts (sardine, mackerel and 2 species of smelt) and geographic range (Oregon and California, USA) of VHSV.

  11. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Lepidopteran pheromones; exemption... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a tolerance. Lepidopteran pheromones that are naturally occurring compounds, or identical or...

  12. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Lepidopteran pheromones; exemption... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a tolerance. Lepidopteran pheromones that are naturally occurring compounds, or identical or...

  13. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Lepidopteran pheromones; exemption... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a tolerance. Lepidopteran pheromones that are naturally occurring compounds, or identical or...

  14. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Lepidopteran pheromones; exemption... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a tolerance. Lepidopteran pheromones that are naturally occurring compounds, or identical or...

  15. 40 CFR 180.1153 - Lepidopteran pheromones; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Lepidopteran pheromones; exemption... FOOD Exemptions From Tolerances § 180.1153 Lepidopteran pheromones; exemption from the requirement of a tolerance. Lepidopteran pheromones that are naturally occurring compounds, or identical or...

  16. Complete nucleotide sequence and experimental host range of Okra mosaic virus.

    PubMed

    Stephan, Dirk; Siddiqua, Mahbuba; Ta Hoang, Anh; Engelmann, Jill; Winter, Stephan; Maiss, Edgar

    2008-02-01

    Okra mosaic virus (OkMV) is a tymovirus infecting members of the family Malvaceae. Early infections in okra (Abelmoschus esculentus) lead to yield losses of 12-19.5%. Besides intensive biological characterizations of OkMV only minor molecular data were available. Therefore, we determined the complete nucleotide sequence of a Nigerian isolate of OkMV. The complete genomic RNA (gRNA) comprises 6,223 nt and its genome organization showed three major ORFs coding for a putative movement protein (MP) of M r 73.1 kDa, a large replication-associated protein (RP) of M r 202.4 kDa and a coat protein (CP) of M r 19.6 kDa. Prediction of secondary RNA structures showed three hairpin structures with internal loops in the 5'-untranslated region (UTR) and a 3'-terminal tRNA-like structure (TLS) which comprises the anticodon for valine, typical for a member of the genus Tymovirus. Phylogenetic comparisons based on the RP, MP and CP amino acid sequences showed the close relationship of OkMV not only to other completely sequenced tymoviruses like Kennedya yellow mosaic virus (KYMV), Turnip yellow mosaic virus (TYMV) and Erysimum latent virus (ErLV), but also to Calopogonium yellow vein virus (CalYVV), Clitoria yellow vein virus (CYVV) and Desmodium yellow mottle virus (DYMoV). This is the first report of a complete OkMV genome sequence from one of the various OkMV isolates originating from West Africa described so far. Additionally, the experimental host range of OkMV including several Nicotiana species was determined. PMID:18049886

  17. Virulence of Broad- and Narrow-Host-Range Salmonella enterica Serovars in the Streptomycin-Pretreated Mouse Model

    PubMed Central

    Suar, Mrutyunjay; Jantsch, Jonathan; Hapfelmeier, Siegfried; Kremer, Marcus; Stallmach, Thomas; Barrow, Paul A.; Hardt, Wolf-Dietrich

    2006-01-01

    Salmonella enterica subspecies I serovars are common bacterial pathogens causing diseases ranging from enterocolitis to systemic infections. Some serovars are adapted to specific hosts, whereas others have a broad host range. The molecular mechanisms defining the virulence characteristics and the host range of a given S. enterica serovar are unknown. Streptomycin pretreated mice provide a surrogate host model for studying molecular aspects of the intestinal inflammation (colitis) caused by serovar Typhimurium (S. Hapfelmeier and W. D. Hardt, Trends Microbiol. 13:497-503, 2005). Here, we studied whether this animal model is also useful for studying other S. enterica subspecies I serovars. All three tested strains of the broad-host-range serovar Enteritidis (125109, 5496/98, and 832/99) caused pronounced colitis and systemic infection in streptomycin pretreated mice. Different levels of virulence were observed among three tested strains of the host-adapted serovar Dublin (SARB13, SD2229, and SD3246). Several strains of host restricted serovars were also studied. Two serovar Pullorum strains (X3543 and 449/87) caused intermediate levels of colitis. No intestinal inflammation was observed upon infection with three different serovar Paratyphi A strains (SARB42, 2804/96, and 5314/98) and one serovar Gallinarum strain (X3796). A second serovar Gallinarum strain (287/91) was highly virulent and caused severe colitis. This strain awaits future analysis. In conclusion, the streptomycin pretreated mouse model can provide an additional tool to study virulence factors (i.e., those involved in enteropathogenesis) of various S. enterica subspecies I serovars. Five of these strains (125109, 2229, 287/91, 449/87, and SARB42) are subject of Salmonella genome sequencing projects. The streptomycin pretreated mouse model may be useful for testing hypotheses derived from this genomic data. PMID:16369020

  18. Use of wide-host-range bacteriophages to reduce Salmonella on poultry products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteriophages used to treat infections are typically amplified in a pathogenic host. However, this practice introduces the risk of administering any remaining bacteriophage-resistant pathogen during bacteriophage application if separate techniques are less than perfect. In this study, bacteriopha...

  19. Expansion of Groundnut ringspot virus host and geographic ranges in solanaceous vegetables in peninsular Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report provides a timely account of Groundnut ringspot virus infection of additional hosts (pepper, tomatillo and eggplant) and in additional locations to growers, Extension personnel, crop consultants, and state and Federal regulatory and research scientists....

  20. Host range and distribution of fruit-infesting pestiferous fruit flies (Diptera, Tephritidae) in selected areas of Central Tanzania.

    PubMed

    Mwatawala, M W; De Meyer, M; Makundi, R H; Maerere, A P

    2009-12-01

    The host range of major fruit fly pests in Central Tanzania was evaluated from October 2004 to October 2006. Samples of 48 potential hosts were collected and incubated for fruit fly emergence. Bactrocera invadens was the dominant species in incidence expressed as the ratio of infested to total number samples collected, as well as infestation rate, expressed as number of flies emerging per unit weight. Eight new host fruits are reported. Infestation by native pests, such as Ceratitis capitata and C. cosyra, was minor compared to B. invadens. Ceratitis rosa was the dominant species in temperate fruits, and Cucurbitaceae were mainly infested by Bactrocera cucurbitae, a specialized cucurbit feeder. Among commercial fruits, high infestation incidences were observed in mango and guava, but they decreased throughout the fruiting season. Low infestation rates were observed in all Citrus species and in avocado, indicating these fruits as poor hosts for the studied fruit fly pests in this region. Widespread availability and abundance of fruit species studied here ensures year-round breeding of B. invadens. Seasonal infestation differs, with mango being the most important host in October to January, while guava being important from February to August. Tropical almond showed very high incidence and infestation rate for B. invadens and might act as an important reservoir host, bridging the fruiting seasons of mango and guava. Soursop acts as an important host for C. cosyra after the mango season. Ceratitis capitata is a pest of minor importance of the commercial fruits studied in this region. PMID:19323850

  1. Cry1F resistance among lepidopteran pests: a model for improved resistance management?

    PubMed

    Vélez, Ana M; Vellichirammal, Neetha Nanoth; Jurat-Fuentes, Juan Luis; Siegfried, Blair D

    2016-06-01

    The Cry1Fa protein from the bacterium Bacillus thuringiensis (Bt) is known for its potential to control lepidopteran pests, especially through transgenic expression in maize and cotton. The maize event TC1507 expressing the cry1Fa toxin gene became commercially available in the United States in 2003 for the management of key lepidopteran pests including the European corn borer, Ostrinia nubilalis, and the fall armyworm, Spodoptera frugiperda. A high-dose/refuge strategy has been widely adopted to delay evolution of resistance to event TC1507 and other transgenic Bt crops. Efficacy of this strategy depends on the crops expressing a high dose of the Bt toxin to targeted pests and adjacent refuges of non-Bt host plants serving as a source of abundant susceptible insects. While this strategy has proved effective in delaying O. nubilalis resistance, field-evolved resistance to event TC1507 has been reported in S. frugiperda populations in Puerto Rico, Brazil, and the southeastern United States. This paper examines available information on resistance to Cry1Fa in O. nubilalis and S. frugiperda and discusses how this information identifies opportunities to refine resistance management recommendations for Bt maize. PMID:27436741

  2. All Five Host-Range Variants of Xanthomonas citri Carry One pthA Homolog With 17.5 Repeats That Determines Pathogenicity on Citrus, but None Determine Host-Range Variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus canker disease is caused by five groups of Xanthomonas citri strains that are distinguished primarily by host range: three from Asia (A, A*, and Aw) and two that form a phylogenetically distinct clade and originated in South America (B and C). Every X. citri strain carries multiple DNA fragme...

  3. Complete nucleotide sequence and organization of the mitogenome of the red-spotted apollo butterfly, Parnassius bremeri (Lepidoptera: Papilionidae) and comparison with other lepidopteran insects.

    PubMed

    Kim, Man Il; Baek, Jee Yeon; Kim, Min Jee; Jeong, Heon Cheon; Kim, Ki-Gyoung; Bae, Chang Hwan; Han, Yeon Soo; Jin, Byung Rae; Kim, Iksoo

    2009-10-31

    The 15,389-bp long complete mitogenome of the endangered red-spotted apollo butterfly, Parnassius bremeri (Lepidoptera: Papilionidae) was determined in this study. The start codon for the COI gene in insects has been extensively discussed, and has long remained a matter of some controversy. Herein, we propose that the CGA (arginine) sequence functions as the start codon for the COI gene in lepidopteran insects, on the basis of complete mitogenome sequences of lepidopteran insects, including P. bremeri, as well as additional sequences of the COI start region from a diverse taxonomic range of lepidopteran species (a total of 53 species from 15 families). In our extensive search for a tRNA-like structure in the A+T-rich region, one tRNA(Trp)-like sequence and one tRNA(Leu) (UUR)-like sequence were detected in the P. bremeri A+T-rich region, and one or more tRNA-like structures were detected in the A+T-rich region of the majority of other sequenced lepidopteran insects, thereby indicating that such features occur frequently in the lepidopteran mitogenomes. Phylogenetic analysis using the concatenated 13 amino acid sequences and nucleotide sequences of PCGs of the four macrolepidopteran superfamilies together with the Tortricoidea and Pyraloidea resulted in the successful recovery of a monophyly of Papilionoidea and a monophyly of Bombycoidea. However, the Geometroidea were unexpectedly identified as a sister group of the Bombycoidea, rather than the Papilionoidea. PMID:19823774

  4. Mesoniviruses are mosquito-specific viruses with extensive geographic distribution and host range

    PubMed Central

    2014-01-01

    Background The family Mesoniviridae (order Nidovirales) comprises of a group of positive-sense, single-stranded RNA ([+]ssRNA) viruses isolated from mosquitoes. Findings Thirteen novel insect-specific virus isolates were obtained from mosquitoes collected in Indonesia, Thailand and the USA. By electron microscopy, the virions appeared as spherical particles with a diameter of ~50 nm. Their 20,129 nt to 20,777 nt genomes consist of positive-sense, single-stranded RNA with a poly-A tail. Four isolates from Houston, Texas, and one isolate from Java, Indonesia, were identified as variants of the species Alphamesonivirus-1 which also includes Nam Dinh virus (NDiV) from Vietnam and Cavally virus (CavV) from Côte d’Ivoire. The eight other isolates were identified as variants of three new mesoniviruses, based on genome organization and pairwise evolutionary distances: Karang Sari virus (KSaV) from Java, Bontag Baru virus (BBaV) from Java and Kalimantan, and Kamphaeng Phet virus (KPhV) from Thailand. In comparison with NDiV, the three new mesoniviruses each contained a long insertion (180 – 588 nt) of unknown function in the 5’ region of ORF1a, which accounted for much of the difference in genome size. The insertions contained various short imperfect repeats and may have arisen by recombination or sequence duplication. Conclusions In summary, based on their genome organizations and phylogenetic relationships, thirteen new viruses were identified as members of the family Mesoniviridae, order Nidovirales. Species demarcation criteria employed previously for mesoniviruses would place five of these isolates in the same species as NDiV and CavV (Alphamesonivirus-1) and the other eight isolates would represent three new mesonivirus species (Alphamesonivirus-5, Alphamesonivirus-6 and Alphamesonivirus-7). The observed spatiotemporal distribution over widespread geographic regions and broad species host range in mosquitoes suggests that mesoniviruses may be common in

  5. Silage Collected from Dairy Farms Harbors an Abundance of Listeriaphages with Considerable Host Range and Genome Size Diversity

    PubMed Central

    Vongkamjan, Kitiya; Switt, Andrea Moreno; den Bakker, Henk C.; Fortes, Esther D.

    2012-01-01

    Since the food-borne pathogen Listeria monocytogenes is common in dairy farm environments, it is likely that phages infecting this bacterium (“listeriaphages”) are abundant on dairy farms. To better understand the ecology and diversity of listeriaphages on dairy farms and to develop a diverse phage collection for further studies, silage samples collected on two dairy farms were screened for L. monocytogenes and listeriaphages. While only 4.5% of silage samples tested positive for L. monocytogenes, 47.8% of samples were positive for listeriaphages, containing up to >1.5 × 104 PFU/g. Host range characterization of the 114 phage isolates obtained, with a reference set of 13 L. monocytogenes strains representing the nine major serotypes and four lineages, revealed considerable host range diversity; phage isolates were classified into nine lysis groups. While one serotype 3c strain was not lysed by any phage isolates, serotype 4 strains were highly susceptible to phages and were lysed by 63.2 to 88.6% of phages tested. Overall, 12.3% of phage isolates showed a narrow host range (lysing 1 to 5 strains), while 28.9% of phages represented broad host range (lysing ≥11 strains). Genome sizes of the phage isolates were estimated to range from approximately 26 to 140 kb. The extensive host range and genomic diversity of phages observed here suggest an important role of phages in the ecology of L. monocytogenes on dairy farms. In addition, the phage collection developed here has the potential to facilitate further development of phage-based biocontrol strategies (e.g., in silage) and other phage-based tools. PMID:23042180

  6. Host range determination of Colletotrichum gloeosporioides f. sp. salsolae, a biological control agent of tumbleweed: from BLUPs to biomass loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host range tests were conducted with Colletotrichum gloeosporioides f. sp. salsolae (CGS) in quarantine to determine whether the fungus is safe to release in N. America for biological control of tumbleweed (Salsola tragus L., Chenopodiaceae). Ninety-two accessions were analyzed from 19 families and...

  7. Biology and host range of Heterapoderopsis bicallosicollis; a potential biological control agent for Chinese tallow Triadica sebifera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chinese tallow, Triadica sebifera, is an invasive weed that infests natural and agricultural areas of the southeastern USA. A candidate for biological control of Chinese tallow has been studied under quarantine conditions. The biology and host range of a primitive leaf feeding beetle, Heterapoderops...

  8. Physiological host range of Ceratapion basicorne, a prospective biological control agent of Centaurea solstitialis (Asteraceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ceratapion basicorne (Coleoptera: Apionidae) is a weevil native to Europe and western Asia has been proposed as a prospective classical biological control agent of yellow starthistle (Centaurea solstitialis), which is an important invasive alien weed in the western United States. Host plant specifi...

  9. Risk Assessment Studies: Detailed Host Range Testing of Wild-Type Cabbage Moth, Mamestra brassicae (Lepidoptera: Noctuidae), Nuclear Polyhedrosis Virus

    PubMed Central

    Doyle, Cathy J.; Hirst, Mark L.; Cory, Jenny S.; Entwistle, Philip F.

    1990-01-01

    The host range of a multiply enveloped nuclear polyhedrosis virus (NPV) (Baculoviridae) isolated from the cabbage moth, Mamestra brassicae (Lepidoptera: Noctuidae), was determined by challenging a wide range of insect species with high (106 polyhedral inclusion bodies) and low (103 polyhedral inclusion bodies) doses of the virus. The identity of the progeny virus was confirmed by dot blotting. Analysis of 50% lethal dose was carried out on selected species, and the progeny virus was identified by using restriction enzyme analysis and Southern blotting. Other than the Lepidoptera, none of the species tested was susceptible to M. brassicae NPV. Within the Lepidoptera, M. brassicae NPV was infective to members of four families (Noctuidae, Geometridae, Yponomeutidae, and Nymphalidae). Of 66 lepidopterous species tested, M. brassicae NPV was cross-infective to 32 of them; however, 91% of the susceptible species were in the Noctuidae. The relevance of host range data in risk assessment studies is discussed. Images PMID:16348279

  10. Expanded range and new host species of Mycobacterium shottsii and M. pseudoshottsii.

    PubMed

    Stine, Cynthia B; Jacobs, John M; Rhodes, Matt R; Overton, Anthony; Fast, Mark; Baya, Ana M

    2009-09-01

    Mycobacterium shottsii and M. pseudoshottsii are recently described mycobacteria commonly isolated from Chesapeake Bay striped bass Morone saxatilis. However, their distribution in striped bass outside of the Chesapeake region and their ability to infect alternative hosts have not been described. Mycobacteria identified as M. shottsii (based on fatty acid methyl ester analysis and multigene sequencing) were isolated from striped bass collected in Albemarle Sound, North Carolina, and white perch Morone americana in the Rhode River, Maryland, and detected in striped bass from the New York Bight off Long Island, New York. Mycobacterium pseudoshottsii were isolated from white perch in the Rhode and Corsica rivers, Maryland, and detected in striped bass in the New York Bight. This work demonstrates that these mycobacteria can be found outside of the Chesapeake Bay as well as in hosts other than striped bass. PMID:20043404

  11. Amerindian Helicobacter pylori Strains Go Extinct, as European Strains Expand Their Host Range

    PubMed Central

    Domínguez-Bello, Maria G.; Pérez, Maria E.; Bortolini, Maria C.; Salzano, Francisco M.; Pericchi, Luis R.; Zambrano-Guzmán, Orlisbeth; Linz, Bodo

    2008-01-01

    We studied the diversity of bacteria and host in the H. pylori-human model. The human indigenous bacterium H. pylori diverged along with humans, into African, European, Asian and Amerindian groups. Of these, Amerindians have the least genetic diversity. Since niche diversity widens the sets of resources for colonizing species, we predicted that the Amerindian H. pylori strains would be the least diverse. We analyzed the multilocus sequence (7 housekeeping genes) of 131 strains: 19 cultured from Africans, 36 from Spanish, 11 from Koreans, 43 from Amerindians and 22 from South American Mestizos. We found that all strains that had been cultured from Africans were African strains (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed strains: hspAmerind and hpEurope strains had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos. The least genetically diverse H. pylori strains were hspAmerind. Strains hpEurope were the most diverse and showed remarkable multilocus sequence mosaicism (indicating recombination). The lower genetic structure in hpEurope strains is consistent with colonization of a diversity of hosts. If diversity is important for the success of H. pylori, then the low diversity of Amerindian strains might be linked to their apparent tendency to disappear. This suggests that Amerindian strains may lack the needed diversity to survive the diversity brought by non-Amerindian hosts. PMID:18830403

  12. Novel Papillomaviruses in Free-Ranging Iberian Bats: No Virus–Host Co-evolution, No Strict Host Specificity, and Hints for Recombination

    PubMed Central

    García-Pérez, Raquel; Ibáñez, Carlos; Godínez, Jose M.; Aréchiga, Nidia; Garin, Inazio; Pérez-Suárez, Gonzalo; de Paz, Oscar; Juste, Javier; Echevarría, Juan E.; Bravo, Ignacio G.

    2014-01-01

    Papillomaviruses (PVs) are widespread pathogens. However, the extent of PV infections in bats remains largely unknown. This work represents the first comprehensive study of PVs in Iberian bats. We identified four novel PVs in the mucosa of free-ranging Eptesicus serotinus (EserPV1, EserPV2, and EserPV3) and Rhinolophus ferrumequinum (RferPV1) individuals and analyzed their phylogenetic relationships within the viral family. We further assessed their prevalence in different populations of E. serotinus and its close relative E. isabellinus. Although it is frequent to read that PVs co-evolve with their host, that PVs are highly species-specific, and that PVs do not usually recombine, our results suggest otherwise. First, strict virus–host co-evolution is rejected by the existence of five, distantly related bat PV lineages and by the lack of congruence between bats and bat PVs phylogenies. Second, the ability of EserPV2 and EserPV3 to infect two different bat species (E. serotinus and E. isabellinus) argues against strict host specificity. Finally, the description of a second noncoding region in the RferPV1 genome reinforces the view of an increased susceptibility to recombination in the E2-L2 genomic region. These findings prompt the question of whether the prevailing paradigms regarding PVs evolution should be reconsidered. PMID:24391150

  13. Limits to the host range of the highly polyphagous tephritid fruit fly Anastrepha ludens in its natural habitat.

    PubMed

    Birke, A; Acosta, E; Aluja, M

    2015-12-01

    Anastepha ludens (Diptera: Tephritidae) is a highly polyphagous fruit fly that is able to develop in a wide range of hosts. Understanding the limits of this pest's host range could provide valuable information for pest management and plant breeding for pest resistance. Previous studies have shown that guavas (Psidium guajava (Myrtaceae) L.), are not attacked under natural conditions by A. ludens. To understand this phenomenon, guavas were exposed to natural infestation by A. ludens and to other fruit fly species that infest guavas in nature (Anastrepha striata Schiner, Anastepha fraterculus (Wiedemann), Anastepha obliqua (Macquart)). Once the susceptible phenological stage of guavas was determined, fruit infestation levels were compared between A. ludens and A. striata. Choice and non-choice tests were performed under field-cage conditions. Under field conditions, guavas were susceptible to A. striata and A. fraterculus attack all the way from when fruit was undeveloped to when fruit began to ripen. No infestation by A. ludens was recorded under natural conditions. Similar results were obtained when forced exposures were performed, indicating that unripe guavas were preferred by A. striata over ripe fruit, and that infestation rates were higher at early fruit maturity stages. Under forced oviposition conditions, A. ludens larvae were unable to develop in unripe guavas but did so in fully ripe fruit. However, A. ludens fitness parameters were dramatically affected, exhibiting reduced survival and reduced pupal weight compared to conspecifics that developed in a natural host, grapefruit. We confirm that P. guajava should not be treated as a natural host of this pestiferous species, and suggest that both behavioral aspects and the fact that larvae are unable to adequately develop in this fruit, indeed represent clear limits to A. ludens's broad host range. PMID:26343267

  14. M062 Is a Host Range Factor Essential for Myxoma Virus Pathogenesis and Functions as an Antagonist of Host SAMD9 in Human Cells▿ †

    PubMed Central

    Liu, Jia; Wennier, Sonia; Zhang, Leiliang; McFadden, Grant

    2011-01-01

    Myxoma virus (MYXV) M062R is a functional homolog of the C7L family of host range genes from orthopoxviruses. We constructed a targeted M062R-knockout-MYXV (vMyxM062-KO) and characterized its properties in vitro and in vivo. In European rabbits, infection by vMyxM062-KO was completely asymptomatic. The surviving rabbits did not gain full protection against the subsequent lethal-dose challenge with wild-type MYXV. We also looked for cellular tropism defects in a variety of cultured cells. In all of the rabbit cells tested, vMyxM062-KO conducts an abortive infection, although it initiates viral DNA replication. In many, but not all, human cancer cells that are permissive for wild-type MYXV, vMyxM062-KO exhibited a profound replication defect. We categorized human cells tested into two groups: (i) type A, which support productive replication for wild-type MYXV but are unable to produce significant levels of progeny virus by vMyxM062-KO, and (ii) type B, which are permissive to infections by both wild-type MYXV and vMyxM062-KO. Furthermore, using proteomic strategies, we identified sterile α motif domain containing 9 (SAMD9), an interferon-regulated cellular protein implicated in human inflammatory disorders, as a unique host binding partner of M062 in human cells. Significantly, knocking down SAMD9 in type A human cancer cells led to a substantial rescue of vMyxM062-KO infection. In summary, M062 is a novel host range factor that controls productive MYXV replication in rabbit cells and in a wide variety of human cells. M062 also binds and antagonizes cellular SAMD9 in human cells, suggesting that SAMD9 is a novel innate antiviral factor against poxviruses. PMID:21248034

  15. [Range of the hosts of the causative agent of pébrine (Nosema bombycis) in the mulberry silkworm].

    PubMed

    Kashkarova, L F; Khakhanov, A I

    1980-01-01

    Biological interrelations between the agent of microsporidiosis of the silkworm and local species of insects were studied. 7 species of Lepidoptera (Agrotis segetum, Chloridea obsoleta, Laphygma exigua, Plusia gamma, Pieris brassicae, P. rapae, Lymantria dispar) were infected with the suspension of Nosema bombycis spores. Results have shown that 6 species of insects are susceptible to Nosema bombycis excluding only the gipsy moth. So, N. bombycis can be considered to be a parasite with a wide range of hosts. PMID:6769083

  16. Infection by retroviral vectors outside of their host range in the presence of replication-defective adenovirus.

    PubMed Central

    Adams, R M; Wang, M; Steffen, D; Ledley, F D

    1995-01-01

    Retrovirus infection is normally limited to cells within a specific host range which express a cognate receptor that is recognized by the product of the env gene. We describe retrovirus infection of cells outside of their normal host range when the infection is performed in the presence of a replication-defective adenovirus (dl312). In the presence of adenovirus, several different ecotropic vectors are shown to infect human cell lines (HeLa and PLC/PRF), and a xenotropic vector is shown to infect murine cells (NIH 3T3). Infectivity is demonstrated by 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) staining, selection with G418 for neomycin resistance, and PCR identification of the provirus in infected cells. Infectivity is quantitatively dependent upon both the concentration of adenovirus (10(6) to 10(8) PFU/ml) and the concentration of retrovirus. Infection requires the simultaneous presence of adenovirus in the retrovirus infection medium and is not stimulated by preincubation and removal of adenovirus from the cells before retrovirus infection. The presence of adenovirus is shown to enhance the uptake of fluorescently labeled retrovirus particles into cells outside of their normal host range, demonstrating that the adenovirus enhances viral entry into cells in the absence of the recognized cognate receptor. This observation suggests new opportunities for developing safe retroviral vectors for gene therapy and new mechanisms for the pathogenesis of retroviral disease. PMID:7853530

  17. Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus) via range expansion of Asclepias host plants.

    PubMed

    Lemoine, Nathan P

    2015-01-01

    Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  18. Climate Change May Alter Breeding Ground Distributions of Eastern Migratory Monarchs (Danaus plexippus) via Range Expansion of Asclepias Host Plants

    PubMed Central

    Lemoine, Nathan P.

    2015-01-01

    Climate change can profoundly alter species’ distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  19. Roles of host plants in boll weevil range expansion beyond tropical Mesoamerica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New findings on boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), biology and ecology have had repercussions on the current level of understanding about short- and long-range boll weevil dispersal, and range expansion from its original tropical Mesoamerican habitat. The w...

  20. A Multivalent Adsorption Apparatus Explains the Broad Host Range of Phage phi92: a Comprehensive Genomic and Structural Analysis

    PubMed Central

    Buettner, Falk F. R.; Browning, Christopher; Nazarov, Sergey; Rabsch, Wolfgang; Bethe, Andrea; Oberbeck, Astrid; Bowman, Valorie D.; Stummeyer, Katharina; Mühlenhoff, Martina; Gerardy-Schahn, Rita

    2012-01-01

    Bacteriophage phi92 is a large, lytic myovirus isolated in 1983 from pathogenic Escherichia coli strains that carry a polysialic acid capsule. Here we report the genome organization of phi92, the cryoelectron microscopy reconstruction of its virion, and the reinvestigation of its host specificity. The genome consists of a linear, double-stranded 148,612-bp DNA sequence containing 248 potential open reading frames and 11 putative tRNA genes. Orthologs were found for 130 of the predicted proteins. Most of the virion proteins showed significant sequence similarities to proteins of myoviruses rv5 and PVP-SE1, indicating that phi92 is a new member of the novel genus of rv5-like phages. Reinvestigation of phi92 host specificity showed that the host range is not limited to polysialic acid-encapsulated Escherichia coli but includes most laboratory strains of Escherichia coli and many Salmonella strains. Structure analysis of the phi92 virion demonstrated the presence of four different types of tail fibers and/or tailspikes, which enable the phage to use attachment sites on encapsulated and nonencapsulated bacteria. With this report, we provide the first detailed description of a multivalent, multispecies phage armed with a host cell adsorption apparatus resembling a nanosized Swiss army knife. The genome, structure, and, in particular, the organization of the baseplate of phi92 demonstrate how a bacteriophage can evolve into a multi-pathogen-killing agent. PMID:22787233

  1. Construction of a broad host range shuttle vector for gene cloning and expression in Actinobacillus pleuropneumoniae and other Pasteurellaceae.

    PubMed

    Frey, J

    1992-01-01

    We have constructed a pair of broad host range expression vectors, pJFF224-NX and pJFF224-XN, based on plasmid RSF1010, which enable cloning and efficient expression of genes in Actinobacillus pleuropneumoniae and Pasteurella haemolytica and in Escherichia coli. The vectors consist of the minimal autonomous replicon of the broad host range plasmid RSF1010 and a type II chloramphenicol acetyl transferase gene for chloramphenicol resistance selection. In addition, they contain a gene expression cassette based on the E. coli bacteriophage T4 gene 32 promoter region and a transcription stop signal, which are separated by a segment of multiple cloning sites in both orientations. Electroporation and subsequent selection for chloramphenicol resistance was used for the introduction of the vectors in A. pleuropneumoniae and P. haemolytica. A promoterless xy/E gene from the Pseudomonas putida TOL plasmid was cloned onto pJFF224-NX. This plasmid enabled efficient expression of active catechol2,3oxygenase in A. pleuropneumoniae and P. haemolytica. It was stably maintained in A. pleuropneumoniae without antibiotic selection, showing less than 0.1% loss after 100 generations, while native RSF1010 and other RSF1010-based vectors were unstable in this host. PMID:1448612

  2. Myxoma virus M063R is a host range gene essential for virus replication in rabbit cells.

    PubMed

    Barrett, John W; Shun Chang, Chew; Wang, Gen; Werden, Steven J; Shao, Zhuhong; Barrett, Catherine; Gao, Xiujuan; Belsito, Tara A; Villenevue, Danielle; McFadden, Grant

    2007-04-25

    The myxoma virus M063R gene product exhibits some sequence similarity to the poxvirus host range gene, C7L, of vaccinia virus. To address the potential host range function of the M063R gene product in rabbits, a deletion mutant of myxoma virus (vMyx63KO) was generated and characterized. vMyx63KO replicated to normal titre levels and produced foci that were indistinguishable from those produced by MV in vitro in a monkey kidney cell line (BGMK) that are permissive for wild type MV. However, vMyx63KO failed to replicate in all rabbit cell lines tested, including both primary and established cells lines, as well as cells derived from a variety of tissues. M063R expression was not required for myxoma virus binding, entry or early gene expression, whereas DNA replication was aborted and late genes were not expressed in vMyx63KO infected rabbit cells. Thus, the replication block for vMyx63KO in rabbit cells preceded the stage of late gene expression and DNA replication. Finally, an in vivo pathogenesis study indicated that vMyx63KO failed to cause any signs of classic myxomatosis in infected rabbits, but functioned as a non-replicating vaccine and provided protection for subsequent challenge by wild type myxoma virus. Altogether, these observations demonstrate that M063R plays a critical role in determining the host specificity of myxoma virus in rabbit cells. PMID:17184804

  3. Isolation and characterization of a T4-like phage with a relatively wide host range within Escherichia coli.

    PubMed

    Xu, Juntian; Chen, Mianmian; He, Lingchen; Zhang, Shuqing; Ding, Tianyun; Yao, Huochun; Lu, Chengping; Zhang, Wei

    2016-04-01

    Avian pathogenic Escherichia coli (APEC) causes colibacillosis in poultry, resulting in severe economic losses worldwide. Coliphages represent alternative antibacterial substitutes based on high lytic efficiency and few side-effects. However, the complete genome sequences information of APEC phages are limited, and knowledge of undesired genes and the narrow host range restrict their applications. In this study, we isolated a virulent phage QL01, with a relatively broad lytic spectrum (41 of 78 APEC strains). Transmission electron micrography showed it belonged to the family Myoviridae with an elongated head and a contractile tail. Whole genome sequencing revealed a linear double-stranded DNA (170,527 kb; GC content, 39.6%) with 275 possible ORFs. Comparative genome analysis revealed high homology between QL01 and other T4-like phages. However, it also showed some unique features, for example, ORF142 and ORF143, which encode IP9 and IP8, respectively, and may counteract host resistance only exist in a few T4-like phages such as IME08 and vB_EcoM_VR5. Furthermore, phage therapy in artificially infected ducks showed a 26.67% decrease in mortality compared with the untreated group. Our study indicates the potential antibacterial function of phage QL01 against APEC infections and highlights unique molecular features underlying the relatively broad host range. PMID:26697952

  4. Analysis of host range restriction determinants in the rabbit model: comparison of homologous and heterologous rotavirus infections.

    PubMed

    Ciarlet, M; Estes, M K; Barone, C; Ramig, R F; Conner, M E

    1998-03-01

    The main limitation of both the rabbit and mouse models of rotavirus infection is that human rotavirus (HRV) strains do not replicate efficiently in either animal. The identification of individual genes necessary for conferring replication competence in a heterologous host is important to an understanding of the host range restriction of rotavirus infections. We recently reported the identification of the P type of the spike protein VP4 of four lapine rotavirus strains as being P[14]. To determine whether VP4 is involved in host range restriction in rabbits, we evaluated infection in rotavirus antibody-free rabbits inoculated orally with two P[14] HRVs, PA169 (G6) and HAL1166 (G8), and with several other HRV strains and animal rotavirus strains of different P and G types. We also evaluated whether the parental rhesus rotavirus (RRV) (P5B[3], G3) and the derived RRV-HRV reassortant candidate vaccine strains RRV x D (G1), RRV x DS-1 (G2), and RRV x ST3 (G4) would productively infect rabbits. Based on virus shedding, limited replication was observed with the P[14] HRV strains and with the SA11 Cl3 (P[2], G3) and SA11 4F (P6[1], G3) animal rotavirus strains, compared to the homologous ALA strain (P[14], G3). However, even limited infection provided complete protection from rotavirus infection when rabbits were challenged orally 28 days postinoculation (DPI) with 10(3) 50% infective doses of ALA rabbit rotavirus. Other HRVs did not productively infect rabbits and provided no significant protection from challenge, in spite of occasional seroconversion. Simian RRV replicated as efficiently as lapine ALA rotavirus in rabbits and provided complete protection from ALA challenge. Live attenuated RRV reassortant vaccine strains resulted in no, limited, or productive infection of rabbits, but all rabbits were completely protected from heterotypic ALA challenge. The altered replication efficiency of the reassortants in rabbits suggests a role for VP7 in host range restriction

  5. North American tree squirrels and ground squirrels with overlapping ranges host different Cryptosporidium species and genotypes.

    PubMed

    Stenger, Brianna L S; Clark, Mark E; Kváč, Martin; Khan, Eakalak; Giddings, Catherine W; Prediger, Jitka; McEvoy, John M

    2015-12-01

    Wildlife-associated Cryptosporidium are an emerging cause of cryptosporidiosis in humans. The present study was undertaken to determine the extent to which North American tree squirrels and ground squirrels host zoonotic Cryptosporidium species and genotypes. Fragments of the Cryptosporidium 18S rRNA and actin genes were amplified and sequenced from fecal samples obtained from three tree squirrel and three ground squirrel species. In tree squirrels, Cryptosporidium was identified in 40.5% (17/42) of American red squirrels (Tamiasciurus hudsonicus), 40.4% (55/136) of eastern gray squirrels (Sciurus carolinensis), and 28.6% (2/7) of fox squirrels (Sciurus niger). Human-pathogenic Cryptosporidium ubiquitum and Cryptosporidium skunk genotype were the most prevalent species/genotypes in tree squirrels. Because tree squirrels live in close proximity to humans and are frequently infected with potentially zoonotic Cryptosporidium species/genotypes, they may be a significant reservoir of infection in humans. In ground squirrels, Cryptosporidium was detected in 70.2% (33/47) of 13-lined ground squirrels (Ictidomys tridecemlineatus), 35.1% (27/77) of black-tailed prairie dogs (Cynomys ludovicianus), and the only golden-mantled ground squirrel (Callospermophilus lateralis) that was sampled. Cryptosporidium rubeyi and ground squirrel genotypes I, II, and III were identified in isolates from these ground squirrel species. In contrast to the Cryptosporidium infecting tree squirrels, these species/genotypes appear to be specific for ground squirrels and are not associated with human disease. PMID:26437239

  6. Dual miRNA Targeting Restricts Host Range and Attenuates Neurovirulence of Flaviviruses

    PubMed Central

    Tsetsarkin, Konstantin A.; Liu, Guangping; Kenney, Heather; Bustos-Arriaga, Jose; Hanson, Christopher T.; Whitehead, Stephen S.; Pletnev, Alexander G.

    2015-01-01

    Mosquito-borne flaviviruses are among the most significant arboviral pathogens worldwide. Vaccinations and mosquito population control programs remain the most reliable means for flavivirus disease prevention, and live attenuated viruses remain one of the most attractive flavivirus vaccine platforms. Some live attenuated viruses are capable of infecting principle mosquito vectors, as demonstrated in the laboratory, which in combination with their intrinsic genetic instability could potentially lead to a vaccine virus reversion back to wild-type in nature, followed by introduction and dissemination of potentially dangerous viral strains into new geographic locations. To mitigate this risk we developed a microRNA-targeting approach that selectively restricts replication of flavivirus in the mosquito host. Introduction of sequences complementary to a mosquito-specific mir-184 and mir-275 miRNAs individually or in combination into the 3’NCR and/or ORF region resulted in selective restriction of dengue type 4 virus (DEN4) replication in mosquito cell lines and adult Aedes mosquitos. Moreover a combined targeting of DEN4 genome with mosquito-specific and vertebrate CNS-specific mir-124 miRNA can silence viral replication in two evolutionally distant biological systems: mosquitoes and mouse brains. Thus, this approach can reinforce the safety of newly developed or existing vaccines for use in humans and could provide an additional level of biosafety for laboratories using viruses with altered pathogenic or transmissibility characteristics. PMID:25906260

  7. Host range susceptibility of Enterococcus sp. strains isolated from diseased turbot: possible routes of infection.

    PubMed Central

    Romalde, J L; Magariños, B; Nuñez, S; Barja, J L; Toranzo, A E

    1996-01-01

    Experiments were conducted to assess the pathogenicity of Enterococcus sp. strains isolated from diseased turbot for several fish species (turbot, salmon, trout, and seabream), as well as for mice. The intraperitoneal injection assays indicated that the tested strains showed host specificity for turbot, with a high degree of virulence (50% lethal dose of 10(4) cells per g of fish). The Spanish Enterococcus sp. isolates were nonpathogenic for the other fish species studied and for mice. The possible routes of infection were determined by bath exposure (with and without prior abrasion of the skin) and by intragastric inoculations with food and feces contaminated with the pathogen. The bath challenges indicated that the Enterococcus isolates were able to overcome the defense mechanisms present on the surface of the turbot only if the skin was abraded prior to the exposure. The antibacterial activities of components of a glycoprotein nature present in the turbot skin mucus are probably responsible in part for the resistance in noninjured fish to infection. On the other hand, we demonstrated the capacity of this pathogen to overcome adverse conditions in the stomachs of fish when associated with food or fecal material, since it is able to establish an infective state and to produce mortalities after 16 to 20 days postingestion. From all of these findings, we can conclude that horizontal transmissions through water and the fecal-oral route are the main avenues of infection of turbot streptococcosis. PMID:8593061

  8. All five host-range variants of Xanthomonas citri carry one pthA homolog with 17.5 repeats that determines pathogenicity on citrus, but none determine host-range variation.

    PubMed

    Al-Saadi, Abdulwahid; Reddy, Joseph D; Duan, Yong P; Brunings, Asha M; Yuan, Qiaoping; Gabriel, Dean W

    2007-08-01

    Citrus canker disease is caused by five groups of Xanthomonas citri strains that are distinguished primarily by host range: three from Asia (A, A*, and A(w)) and two that form a phylogenetically distinct clade and originated in South America (B and C). Every X. citri strain carries multiple DNA fragments that hybridize with pthA, which is essential for the pathogenicity of wide-host-range X. citri group A strain 3213. DNA fragments that hybridized with pthA were cloned from a representative strain from all five groups. Each strain carried one and only one pthA homolog that functionally complemented a knockout mutation of pthA in 3213. Every complementing homolog was of identical size to pthA and carried 17.5 nearly identical, direct tandem repeats, including three new genes from narrow-host-range groups C (pthC), A(w) (pthAW), and A* (pthA*). Every noncomplementing paralog was of a different size; one of these was sequenced from group A* (pthA*-2) and was found to have an intact promoter and full-length reading frame but with 15.5 repeats. None of the complementing homologs nor any of the noncomplementing paralogs conferred avirulence to 3213 on grapefruit or suppressed avirulence of a group A* strain on grapefruit. A knockout mutation of pthC in a group C strain resulted in loss of pathogenicity on lime, but the strain was unaffected in ability to elicit an HR on grapefruit. This pthC- mutant was fully complemented by pthA, pthB, or pthC. Analysis of the predicted amino-acid sequences of all functional pthA homologs and nonfunctional paralogs indicated that the specific sequence of the 17th repeat may be essential for pathogenicity of X. citri on citrus. PMID:17722697

  9. New host and expanded geographic range of the stellate scale, Vinsonia stellifera (Westwood) (Hemiptera: Coccidae: Ceroplastinae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The stellate scale, Vinsonia stellifera (Westwood), is a polyphagous wax scale with a distribution spanning across the tropics and subtropics of both the northern and southern hemispheres. This insect feeds on a wide range of plant taxa and can occur in high densities on a single plant. As a resul...

  10. GEOGRAPHIC AND HOST RANGE OF THE NEMATODE SOBOLIPHYME BATURINI ACROSS BERINGIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The nematode Soboliphyme baturini Petrov, 1930 was found to represent a single species with relatively broad geographic range across Beringia and northwestern North America, based on assessment of molecular sequence data for adult and juvenile parasites. Refuted are hypotheses suggesting that severa...

  11. Newcastle disease virus fusion and haemagglutinin-neuraminidase proteins contribute to its macrophage host range

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Newcastle disease virus (NDV) is an avian paramyxovirus that causes significant economic damage to international poultry industry. Different strains of NDV express a wide range of virulence that is primarily dependent on the amino acid sequence of the strain’s fusion (F) protein cleavage site. Two c...

  12. Isolation of Lactococcal Prolate Phage-Phage Recombinants by an Enrichment Strategy Reveals Two Novel Host Range Determinants

    PubMed Central

    Rakonjac, Jasna; O'Toole, Paul W.; Lubbers, Mark

    2005-01-01

    Virulent lactococcal prolate (or c2-like) phages are the second most common phage group that causes fermentation failure in the dairy industry. We have mapped two host range determinants in two lactococcal prolate phages, c2 and 923, for the host strains MG1363 and 112. Each phage replicates on only one of the two host strains: c2 on MG1363 and 923 on 112. Phage-phage recombinants that replicated on both strains were isolated by a new method that does not require direct selection but rather employs an enrichment protocol. After initial mixed infection of strain 112, two rotations, the first of which was carried out on strain MG1363 and the second on 112, permitted continuous amplification of double-plating recombinants while rendering one of the parent phages unamplified in each of the two rotations. Mapping of the recombination endpoints showed that the presence of the N-terminal two-thirds of the tail protein L10 of phage c2 and a 1,562-bp cosR-terminal fragment of phage 923 genome overcame blocks of infection in strains MG1363 and 112, respectively. Both infection inhibition mechanisms act at the stage of DNA entry; in strain MG1363, the infection block acts early, before phage DNA enters the cytoplasm, and in strain 112, it acts late, after most of the DNA has entered the cell but before it undergoes cos-end ligation. These are the first reported host range determinants in bacteriophage of lactic acid bacteria required for overcoming inhibition of infection at the stage of DNA entry and cos-end ligation. PMID:15838038

  13. Phenolic Compounds and Their Fates In Tropical Lepidopteran Larvae: Modifications In Alkaline Conditions.

    PubMed

    Vihakas, Matti; Gómez, Isrrael; Karonen, Maarit; Tähtinen, Petri; Sääksjärvi, Ilari; Salminen, Juha-Pekka

    2015-09-01

    Lepidopteran larvae encounter a variety of phenolic compounds while consuming their host plants. Some phenolics may oxidize under alkaline conditions prevailing in the larval guts, and the oxidation products may cause oxidative stress to the larvae. In this study, we aimed to find new ways to predict how phenolic compounds may be modified in the guts of herbivorous larvae. To do so, we studied the ease of oxidation of phenolic compounds from 12 tropical tree species. The leaf extracts were incubated in vitro in alkaline conditions, and the loss of total phenolics during incubation was used to estimate the oxidizability of extracts. The phenolic profiles of the leaf extracts before and after incubation were compared, revealing that some phenolic compounds were depleted during incubation. The leaves of the 12 tree species were each fed to 12 species of lepidopteran larvae that naturally feed on these trees. The phenolic profiles of larval frass were compared to those of in vitro incubated leaf extracts. These comparisons showed that the phenolic profiles of alkali-treated samples and frass samples were similar in many cases. This suggested that certain phenolics, such as ellagitannins, proanthocyanidins, and galloylquinic acid derivatives were modified by the alkaline pH of the larval gut. In other cases, the chromatographic profiles of frass and in vitro incubated leaf extracts were not similar, and new modifications of phenolics were detected in the frass. We conclude that the actual fates of phenolics in vivo are often more complicated than can be predicted by a simple in vitro method. PMID:26364295

  14. Fulfillment of Koch’s postulates and partial host range of Septoria lepidii Desm., a fungal pathogen for potential biological control of hoary cress (Lepidium spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have fulfilled Koch’s postulates and conducted host range tests with Septoria lepidii Desm. on five geographical accessions of hoary cress. Host range results showed the fungus specific to Lepidium spp. and damaging to hoary cress. This fungus is potentially an important biological control agent ...

  15. Canine parvovirus host range is determined by the specific conformation of an additional region of the capsid.

    PubMed Central

    Parker, J S; Parrish, C R

    1997-01-01

    We analyzed a region of the capsid of canine parvovirus (CPV) which determines the ability of the virus to infect canine cells. This region is distinct from those previously shown to determine the canine host range differences between CPV and feline panleukopenia virus. It lies on a ridge of the threefold spike of the capsid and is comprised of five interacting loops from three capsid protein monomers. We analyzed 12 mutants of CPV which contained amino acid changes in two adjacent loops exposed on the surface of this region. Nine mutants infected and grew in feline cells but were restricted in replication in one or the other of two canine cell lines tested. Three other mutants whose genomes contain mutations which affect one probable interchain bond were nonviable and could not be propagated in either canine or feline cells, although the VP1 and VP2 proteins from those mutants produced empty capsids when expressed from a plasmid vector. Although wild-type and mutant capsids bound to canine and feline cells in similar amounts, infection or viral DNA replication was greatly reduced after inoculation of canine cells with most of the mutants. The viral genomes of two host range-restricted mutants and two nonviable mutants replicated to wild-type levels in both feline and canine cells upon transfection with plasmid clones. The capsids of wild-type CPV and two mutants were similar in susceptibility to heat inactivation, but one of those mutants and one other were more stable against urea denaturation. Most mutations in this structural region altered the ability of monoclonal antibodies to recognize epitopes within a major neutralizing antigenic site, and that site could be subdivided into a number of distinct epitopes. These results argue that a specific structure of this region is required for CPV to retain its canine host range. PMID:9371580

  16. Characterization of Extended-Host-Range Pseudo-T-Even Bacteriophage Kpp95 Isolated on Klebsiella pneumoniae▿

    PubMed Central

    Wu, Lii-Tzu; Chang, Shu-Ying; Yen, Ming-Ren; Yang, Tsuey-Ching; Tseng, Yi-Hsiung

    2007-01-01

    Kpp95, isolated on Klebsiella pneumoniae, is a bacteriophage with the morphology of T4-type phages and is capable of rapid lysis of host cells. Its double-stranded genomic DNA (ca. 175 kb, estimated by pulsed-field gel electrophoresis) can be cut only by restriction endonucleases with a cleavage site flanked either by A and T or by T, as tested, suggesting that it contains the modified derivative(s) of G and/or C. Over 26 protein bands were visualized upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the virion proteins. N-terminal sequencing indicated that the most abundant band (46 kDa) is the major coat protein (gp23) which has been cleaved from a signal peptide likely with a length similar to that of T4. Phylogenetic analyses based on the sequences of the central region (263 amino acid residues) of gp23 and the full length of gp18 and gp19 placed Kpp95 among the pseudo-T-even subgroup, most closely related to the coliphage JS98. In addition to being able to lyse many extended-spectrum β-lactamase strains of K. pneumoniae, Kpp95 can lyse Klebsiella oxytoca, Enterobacter agglomerans, and Serratia marcescens cells. Thus, Kpp95 deserves further studies for development as a component of a therapeutic cocktail, owing to its high efficiencies of host lysis plus extended host range. PMID:17337566

  17. Characterization of extended-host-range pseudo-T-even bacteriophage Kpp95 isolated on Klebsiella pneumoniae.

    PubMed

    Wu, Lii-Tzu; Chang, Shu-Ying; Yen, Ming-Ren; Yang, Tsuey-Ching; Tseng, Yi-Hsiung

    2007-04-01

    Kpp95, isolated on Klebsiella pneumoniae, is a bacteriophage with the morphology of T4-type phages and is capable of rapid lysis of host cells. Its double-stranded genomic DNA (ca. 175 kb, estimated by pulsed-field gel electrophoresis) can be cut only by restriction endonucleases with a cleavage site flanked either by A and T or by T, as tested, suggesting that it contains the modified derivative(s) of G and/or C. Over 26 protein bands were visualized upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the virion proteins. N-terminal sequencing indicated that the most abundant band (46 kDa) is the major coat protein (gp23) which has been cleaved from a signal peptide likely with a length similar to that of T4. Phylogenetic analyses based on the sequences of the central region (263 amino acid residues) of gp23 and the full length of gp18 and gp19 placed Kpp95 among the pseudo-T-even subgroup, most closely related to the coliphage JS98. In addition to being able to lyse many extended-spectrum beta-lactamase strains of K. pneumoniae, Kpp95 can lyse Klebsiella oxytoca, Enterobacter agglomerans, and Serratia marcescens cells. Thus, Kpp95 deserves further studies for development as a component of a therapeutic cocktail, owing to its high efficiencies of host lysis plus extended host range. PMID:17337566

  18. Range of phytoplasma concentrations in various plant hosts as determined by competitive polymerase chain reaction.

    PubMed

    Berges, R; Rott, M; Seemüller, E

    2000-10-01

    ABSTRACT For competitive polymerase chain reaction (PCR), an internal standard DNA template was developed that consisted of a highly conserved, internally deleted 16S rDNA fragment of an aster yellows phytoplasma. The internal standard was calibrated using a quantified culture of Acholeplasma laidlawii. Serial dilutions of the internal standard and fixed amounts of target templates from infected plants were coamplified with the same primers, and the products obtained were quantified using an enzyme-linked immunosorbent assay procedure. Analysis of the data revealed that the phytoplasma concentration in the plants examined differed by a factor of about 4 x 10(6). Phytoplasma concentrations of 2.2 x 10(8) to 1.5 x 10(9) cells per g of tissue were identified in periwinkles infected with various phytoplasmas. High to moderate concentrations were detected in Malus domestica (apple) genotypes infected with the apple proliferation phytoplasma, Alnus glutinosa (alder) genotypes infected with the alder yellows phytoplasma, and most aster yellows-infected Populus (poplar) genotypes examined. Very low phytoplasma concentrations, ranging from 370 to 34,000 cells per g of tissue, were identified in proliferation-diseased apple trees on resistant rootstocks 4551 and 4608, yellows-diseased Quercus robur (oak) trees, and Carpinus betulus (hornbeam) trees. Such low concentrations, which corresponded to about 4 to 340 cells in the reaction mixture, could only be detected and quantified by nested PCR. PMID:18944479

  19. 76 FR 60448 - Syngenta Biotechnology, Inc.; Determination of Nonregulated Status for Lepidopteran-Resistant Cotton

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... in 7 CFR part 340. In a notice \\1\\ published in the Federal Register on May 11, 2011 (76 FR 27301... protect cotton plants from lepidopteran insect damage, is no longer considered a regulated article under... cotton plants from lepidopteran insect damage. The petition stated that cotton event COT67B is...

  20. Update on monitoring of resistance to Bt cotton in key lepidopteran pests in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers sprayed more Bollgard II to control target lepidopteran pests in 2010 than in previous years, and therefore concerns have been expressed that the susceptibility of the target lepidopteran pests to the Bt Cry1Ac and Cry2Ab proteins in Bollgard II has significantly decreased. However, resist...

  1. A single amino acid in the PB2 gene of influenza A virus is a determinant of host range.

    PubMed Central

    Subbarao, E K; London, W; Murphy, B R

    1993-01-01

    The single gene reassortant virus that derives its PB2 gene from the avian influenza A/Mallard/NY/78 virus and remaining genes from the human influenza A/Los Angeles/2/87 virus exhibits a host range restriction (hr) phenotype characterized by efficient replication in avian tissue and failure to produce plaques in mammalian Madin-Darby canine kidney cells. The hr phenotype is associated with restriction of viral replication in the respiratory tract of squirrel monkeys and humans. To identify the genetic basis of the hr phenotype, we isolated four phenotypic hr mutant viruses that acquired the ability to replicate efficiently in mammalian tissue. Segregational analysis indicated that the loss of the hr phenotype was due to a mutation in the PB2 gene itself. The nucleotide sequences of the PB2 gene of each of the four hr mutants revealed that a single amino acid substitution at position 627 (Glu-->Lys) was responsible for the restoration of the ability of the PB2 single gene reassortant to replicate in Madin-Darby canine kidney cells. Interestingly, the amino acid at position 627 in every avian influenza A virus PB2 protein analyzed to date is glutamic acid, and in every human influenza A virus PB2 protein, it is lysine. Thus, the amino acid at residue 627 of PB2 is an important determinant of host range of influenza A viruses. PMID:8445709

  2. Emerging Trends in Molecular Interactions between Plants and the Broad Host Range Fungal Pathogens Botrytis cinerea and Sclerotinia sclerotiorum.

    PubMed

    Mbengue, Malick; Navaud, Olivier; Peyraud, Rémi; Barascud, Marielle; Badet, Thomas; Vincent, Rémy; Barbacci, Adelin; Raffaele, Sylvain

    2016-01-01

    Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum, the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi. PMID:27066056

  3. Emerging Trends in Molecular Interactions between Plants and the Broad Host Range Fungal Pathogens Botrytis cinerea and Sclerotinia sclerotiorum

    PubMed Central

    Mbengue, Malick; Navaud, Olivier; Peyraud, Rémi; Barascud, Marielle; Badet, Thomas; Vincent, Rémy; Barbacci, Adelin; Raffaele, Sylvain

    2016-01-01

    Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum, the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi. PMID:27066056

  4. Broad host range vectors derived from an RSF1010::Tn1 plasmid.

    PubMed

    Chistoserdov, A Y; Tsygankov, Y D

    1986-11-01

    Plasmid vector derivatives of the IncQ/P4 plasmid RSF1010 available for cloning DNA into a broad range of bacterial species were constructed. The plasmid pAYC31 constructed for the positive selection of inserted fragments contains part of transposon Tn1 inserted into the sequence of the gene sul. Gene aph transcription in pAYC31 can be initiated from the promoter for the transposase gene tnpA which is under the negative control of the gene tnpR product (Heffron, 1983). The insertion of a BamHI fragment, or of fragments generated by Sau3A, BclI, BglII, or XhoII digestion into the unique BamHI site within the gene tnpR sequence, leads to initiation of transcription from the promoter of the tnpA gene toward the aph gene. Expression of the aph gene upon insertion of a BamHI restriction fragment provides a positive selection for hybrid plasmids by plating the transformed bacteria on media with streptomycin. Versatile cloning vectors pAYC32 of 9.7 kb in length and pAYC39 of 11.3 kb in length were also constructed. Insertion into the BamHI site of vector pAYC32 of a 1.6-kb BglII fragment that contains the lambda cos site produced cosmid vectors pAYC51 and pAYC52. The two 11.3-kb cosmids differ only by the orientation of the 1.6-kb BglII fragment. By insertion into the BamHI site of pAYC32 of a BglII-BamHI fragment of plasmid pHC79 that contains the gene tet and lambda cos site cosmid vector pAYC53 was constructed. Vector pAYC31 was used to construct a gene bank from the chromosomal DNA of an obligate methylotrophic strain Methylomicrobium flagellatum KT. PMID:3027724

  5. Characterization of an Ancient Lepidopteran Lateral Gene Transfer

    PubMed Central

    Wheeler, David; Redding, Amanda J.; Werren, John H.

    2013-01-01

    Bacteria to eukaryote lateral gene transfers (LGT) are an important potential source of material for the evolution of novel genetic traits. The explosion in the number of newly sequenced genomes provides opportunities to identify and characterize examples of these lateral gene transfer events, and to assess their role in the evolution of new genes. In this paper, we describe an ancient lepidopteran LGT of a glycosyl hydrolase family 31 gene (GH31) from an Enterococcus bacteria. PCR amplification between the LGT and a flanking insect gene confirmed that the GH31 was integrated into the Bombyx mori genome and was not a result of an assembly error. Database searches in combination with degenerate PCR on a panel of 7 lepidopteran families confirmed that the GH31 LGT event occurred deep within the Order approximately 65–145 million years ago. The most basal species in which the LGT was found is Plutella xylostella (superfamily: Yponomeutoidea). Array data from Bombyx mori shows that GH31 is expressed, and low dN/dS ratios indicates the LGT coding sequence is under strong stabilizing selection. These findings provide further support for the proposition that bacterial LGTs are relatively common in insects and likely to be an underappreciated source of adaptive genetic material. PMID:23533610

  6. Genome sequence and analysis of a broad-host range lytic bacteriophage that infects the Bacillus cereus group

    PubMed Central

    2013-01-01

    Background Comparatively little information is available on members of the Myoviridae infecting low G+C content, Gram-positive host bacteria of the family Firmicutes. While numerous Bacillus phages have been isolated up till now only very few Bacillus cereus phages have been characterized in detail. Results Here we present data on the large, virulent, broad-host-range B. cereus phage vB_BceM_Bc431v3 (Bc431v3). Bc431v3 features a 158,618 bp dsDNA genome, encompassing 239 putative open reading frames (ORFs) and, 20 tRNA genes encoding 17 different amino acids. Since pulsed-field gel electrophoresis indicated that the genome of this phage has a mass of 155-158 kb Bc431v3 DNA appears not to contain long terminal repeats that are found in the genome of Bacillus phage SPO1. Conclusions Bc431v3 displays significant sequence similarity, at the protein level, to B. cereus phage BCP78, Listeria phage A511 and Enterococcus phage ØEF24C and other morphologically related phages infecting Firmicutes such as Staphylococcus phage K and Lactobacillus phage LP65. Based on these data we suggest that Bc431v3 should be included as a member of the Spounavirinae; however, because of all the diverse taxonomical information has been addressed recently, it is difficult to determine the genus. The Bc431v3 phage contains some highly unusual genes such as gp143 encoding putative tRNAHis guanylyltransferase. In addition, it carries some genes that appear to be related to the host sporulation regulators. These are: gp098, which encodes a putative segregation protein related to FstK/SpoIIIE DNA transporters; gp105, a putative segregation protein; gp108, RNA polymerase sigma factor F/B; and, gp109 encoding RNA polymerase sigma factor G. PMID:23388049

  7. New Host Range for Hematodinium in Southern Australia and Novel Tools for Sensitive Detection of Parasitic Dinoflagellates

    PubMed Central

    Gornik, Sebastian G.; Cranenburgh, Andrea; Waller, Ross F.

    2013-01-01

    Hematodinium is a parasitic dinoflagellate and emerging pathogen of crustaceans. It preferably manifests in haemolymph of marine decapod crustaceans, killing a large variety of genera with significant impacts on fisheries worldwide. There is, however, evidence that some crustacean stocks harbor high prevalence, low intensity infections that may not result in widespread host mortality and are therefore hard to detect. The most widely used methods for detection of Hematodinium are conventional blood smears and polymerase chain reaction (PCR) against ribosomal RNAs. Blood smears demand a trained investigator, are labor intensive and not readily scalable for high-throughput sampling. PCRs only detect parasite DNA and can also suffer from false negatives and positives. In order to develop alternative detection tools for Hematodinium cells in decapod crustaceans we employed an immunological approach against a newly identified, abundant dinoflagellate-specific nuclear protein—Dinoflagellate/Viral NucleoProtein (DVNP). Both immunofluorescence assay (IFA) and Western blot methods against DVNP showed high sensitivity of detection. The Western blot detects Hematodinium parasites to levels of 25 parasites per milliliter of crustacean haemolymph, with the potential for sample pooling and screening of large samples. Using both PCR and these new tools, we have identified Hematodinium cells present in three new host crab taxa, at high prevalence but with no sign of pathogenesis. This extends the known range of Hematodinium to southern Australia. PMID:24324829

  8. Discovery of a polyomavirus in European badgers (Meles meles) and the evolution of host range in the family Polyomaviridae

    PubMed Central

    Hill, Sarah C.; Murphy, Aisling A.; Cotten, Matthew; Palser, Anne L.; Benson, Phillip; Lesellier, Sandrine; Gormley, Eamonn; Richomme, Céline; Grierson, Sylvia; Bhuachalla, Deirdre Ni; Chambers, Mark; Kellam, Paul; Boschiroli, María-Laura

    2015-01-01

    Polyomaviruses infect a diverse range of mammalian and avian hosts, and are associated with a variety of symptoms. However, it is unknown whether the viruses are found in all mammalian families and the evolutionary history of the polyomaviruses is still unclear. Here, we report the discovery of a novel polyomavirus in the European badger (Meles meles), which to our knowledge represents the first polyomavirus to be characterized in the family Mustelidae, and within a European carnivoran. Although the virus was discovered serendipitously in the supernatant of a cell culture inoculated with badger material, we subsequently confirmed its presence in wild badgers. The European badger polyomavirus was tentatively named Meles meles polyomavirus 1 (MmelPyV1). The genome is 5187 bp long and encodes proteins typical of polyomaviruses. Phylogenetic analyses including all known polyomavirus genomes consistently group MmelPyV1 with California sea lion polyomavirus 1 across all regions of the genome. Further evolutionary analyses revealed phylogenetic discordance amongst polyomavirus genome regions, possibly arising from evolutionary rate heterogeneity, and a complex association between polyomavirus phylogeny and host taxonomic groups. PMID:25626684

  9. Plasmids captured in C. metallidurans CH34: defining the PromA family of broad-host-range plasmids.

    PubMed

    Van der Auwera, Géraldine A; Król, Jaroslaw E; Suzuki, Haruo; Foster, Brian; Van Houdt, Rob; Brown, Celeste J; Mergeay, Max; Top, Eva M

    2009-08-01

    The self-transmissible, broad-host-range (BHR) plasmid pMOL98 was previously isolated from polluted soil using a triparental plasmid capture approach and shown to possess a replicon similar to that of the BHR plasmids pSB102 and pIPO2. Here, complete sequence analysis and comparative genomics reveal that the 55.5 kb nucleotide sequence of pMOL98 shows extensive sequence similarity and synteny with the BHR plasmid family that now includes pIPO2, pSB102, pTER331, and pMRAD02. They share a plasmid backbone comprising replication, partitioning and conjugative transfer functions. Comparison of the variable accessory regions of these plasmids shows that the majority of natural transposons, as well as the mini-transposon used to mark the plasmids, are inserted in the parA locus. The transposon unique to pMOL98 appears to have inserted from the chromosome of the recipient strain used in the plasmid capture procedure. This demonstrates the necessity for careful screening of plasmids and host chromosomes to avoid mis-interpretation of plasmid genome content. The presence of very similar BHR plasmids with different accessory genes in geographically distinct locations suggests an important role in horizontal gene exchange and bacterial adaptation for this recently defined plasmid group, which we propose to name "PromA". PMID:19259779

  10. Discovery of a polyomavirus in European badgers (Meles meles) and the evolution of host range in the family Polyomaviridae.

    PubMed

    Hill, Sarah C; Murphy, Aisling A; Cotten, Matthew; Palser, Anne L; Benson, Phillip; Lesellier, Sandrine; Gormley, Eamonn; Richomme, Céline; Grierson, Sylvia; Bhuachalla, Deirdre Ni; Chambers, Mark; Kellam, Paul; Boschiroli, María-Laura; Ehlers, Bernhard; Jarvis, Michael A; Pybus, Oliver G

    2015-06-01

    Polyomaviruses infect a diverse range of mammalian and avian hosts, and are associated with a variety of symptoms. However, it is unknown whether the viruses are found in all mammalian families and the evolutionary history of the polyomaviruses is still unclear. Here, we report the discovery of a novel polyomavirus in the European badger (Meles meles), which to our knowledge represents the first polyomavirus to be characterized in the family Mustelidae, and within a European carnivoran. Although the virus was discovered serendipitously in the supernatant of a cell culture inoculated with badger material, we subsequently confirmed its presence in wild badgers. The European badger polyomavirus was tentatively named Meles meles polyomavirus 1 (MmelPyV1). The genome is 5187 bp long and encodes proteins typical of polyomaviruses. Phylogenetic analyses including all known polyomavirus genomes consistently group MmelPyV1 with California sea lion polyomavirus 1 across all regions of the genome. Further evolutionary analyses revealed phylogenetic discordance amongst polyomavirus genome regions, possibly arising from evolutionary rate heterogeneity, and a complex association between polyomavirus phylogeny and host taxonomic groups. PMID:25626684

  11. A fusion protein containing a lepidopteran-specific toxin from the South Indian red scorpion (Mesobuthus tamulus) and snowdrop lectin shows oral toxicity to target insects

    PubMed Central

    Trung, Nghia Pham; Fitches, Elaine; Gatehouse, John A

    2006-01-01

    Background Despite evidence suggesting a role in plant defence, the use of plant lectins in crop protection has been hindered by their low and species-specific insecticidal activity. Snowdrop lectin (Galanthus nivalis agglutinin; GNA) is transported to the haemolymph of insects after oral ingestion, and can be used as a basis for novel insecticides. Recombinant proteins containing GNA expressed as a fusion with a peptide or protein, normally only toxic when injected into the insect haemolymph, have the potential to show oral toxicity as a result of GNA-mediated uptake. Results A gene encoding a toxin, ButaIT, from the red scorpion (Mesobuthus tamulus) was synthesised and assembled into expression constructs. One construct contained ButaIT alone, whereas the other contained ButaIT fused N-terminally to a GNA polypeptide (ButaIT/GNA). Both recombinant proteins were produced using the yeast Pichia pastoris as an expression host, and purified. Recombinant ButaIT and ButaIT/GNA were acutely toxic when injected into larvae of tomato moth (Lacanobia oleracea), causing slow paralysis, leading to mortality or decreased growth. ButaIT/GNA was chronically toxic when fed to L. oleracea larvae, causing decreased survival and weight gain under conditions where GNA alone was effectively non-toxic. Intact ButaIT/GNA was detected in larval haemolymph from insects fed the fusion protein orally, demonstrating transport of the linked polypeptide across the gut. Proteolysis of the fusion protein was also observed. ButaIT/GNA was significantly more toxic that GNA alone when fed to the homopteran Nilaparvata lugens (rice brown planthopper) in liquid artificial diet. Conclusion The ButaIT/GNA recombinant fusion protein is toxic to lepidopteran larvae both when injected and when fed orally, showing the utility of GNA as a carrier to transport potentially toxic peptides and proteins across the insect gut. Although ButaIT has been claimed to be lepidopteran-specific, the fusion protein has

  12. The host-range, genomics and proteomics of Escherichia coli O157:H7 bacteriophage rV5

    PubMed Central

    2013-01-01

    Background Bacteriophages (phages) have been used extensively as analytical tools to type bacterial cultures and recently for control of zoonotic foodborne pathogens in foods and in animal reservoirs. Methods We examined the host range, morphology, genome and proteome of the lytic E. coli O157 phage rV5, derived from phage V5, which is a member of an Escherichia coli O157:H7 phage typing set. Results Phage rV5 is a member of the Myoviridae family possessing an icosahedral head of 91 nm between opposite apices. The extended tail measures 121 x 17 nm and has a sheath of 44 x 20 nm and a 7 nm-wide core in the contracted state. It possesses a 137,947 bp genome (43.6 mol%GC) which encodes 233 ORFs and six tRNAs. Until recently this virus appeared to be phylogenetically isolated with almost 70% of its gene products ORFans. rV5 is closely related to coliphages Delta and vB-EcoM-FY3, and more distantly related to Salmonella phages PVP-SE1 and SSE-121, Cronobacter sakazakii phage vB_CsaM_GAP31, and coliphages phAPEC8 and phi92. A complete shotgun proteomic analysis was carried out on rV5, extending what had been gleaned from the genomic analyses. Host range studies revealed that rV5 is active against several other E. coli. PMID:23497209

  13. Is the nestedness of metazoan parasite assemblages of marine fishes from the southeastern Pacific coast a pattern associated with the geographical distributional range of the host?

    PubMed

    González, M T; Oliva, M E

    2009-04-01

    Nested structure is a pattern originally described in island biogeography to characterize how a set of species is distributed among a set of islands. In parasite communities, nestedness has been intensively studied among individual fish from a locality. However, nested patterns among parasite assemblages from different host populations (localities) have scarcely been investigated. We recorded the occurrence of parasites in 9 fish species widely distributed along the southeastern Pacific coast to determine whether the ecto- and endoparasite assemblages of marine fishes show a nested structure associated with host distributional range. Nestedness was tested using Brualdi-Sanderson index of discrepancy (BR); and 5 null models incorporated in a 'Nestedness' programme (Ulrich, 2006). The ecto- and endoparasite richness do not show similar patterns of latitudinal gradients among fish hosts, with 33-66% of analysed ectoparasite assemblages, and 25-75% of endoparasite assemblages showing nested structures through the host distributional range. For ectoparasites, species richness gradients and nested structure (when present) might be associated with decreased host densities or could reflect negative environmental conditions in the distributional border of the host species, whereas for endoparasites might be caused by geographical breaks of prey or changes in prey availability (intermediate hosts). The sampled extension of the distributional range of the host species, as well as the lack of specificity of some parasites, could influence the detection of nestedness. PMID:19195414

  14. Promoters of the Broad Host Range Plasmid Rk2: Analysis of Transcription (Initiation) in Five Species of Gram-Negative Bacteria

    PubMed Central

    Greener, A.; Lehman, S. M.; Helinski, D. R.

    1992-01-01

    A broad host range cloning vector was constructed, suitable for monitoring promoter activity in diverse Gram-negative bacteria. This vector, derived from plasmid RSF1010, utilized the firefly luciferase gene as the reporter, since the assay for its bioluminescent product is sensitive, and measurements can be made without background from the host. Twelve DNA fragments with promoter activity were obtained from broad host range plasmid RK2 and inserted into the RSF1010 derived vector. The relative luciferase activities were determined for these fragments in five species of Gram-negative bacteria. In addition, four promoters were analyzed by primer extension to locate transcriptional start sites in each host. The results show that several of the promoters vary substantially in relative strengths or utilize different transcriptional start sites in different bacteria. Other promoters exhibited similar activities and identical start sites in the five hosts examined. PMID:1732166

  15. Sensory basis of lepidopteran migration: focus on the monarch butterfly.

    PubMed

    Guerra, Patrick A; Reppert, Steven M

    2015-10-01

    In response to seasonal habitats, migratory lepidopterans, exemplified by the monarch butterfly, have evolved migration to deal with dynamic conditions. During migration, monarchs use orientation mechanisms, exploiting a time-compensated sun compass and a light-sensitive inclination magnetic compass to facilitate fall migration south. The sun compass is bidirectional with overwintering coldness triggering the change in orientation direction for remigration northward in the spring. The timing of the remigration and milkweed emergence in the southern US have co-evolved for propagation of the migration. Current research is uncovering the anatomical and molecular substrates that underlie migratory-relevant sensory mechanisms with the antennae being critical components. Orientation mechanisms may be detrimentally affected by environmental factors such as climate change and sensory interference from human-generated sources. PMID:25625216

  16. Genetic structure of Aegilops cylindrica Host in its native range and in the United States of America.

    PubMed

    Gandhi, Harish T; Vales, M Isabel; Mallory-Smith, Carol; Riera-Lizarazu, Oscar

    2009-10-01

    Chloroplast and nuclear microsatellite markers were used to study genetic diversity and genetic structure of Aegilops cylindrica Host collected in its native range and in adventive sites in the USA. Our analysis suggests that Ae. cylindrica, an allotetraploid, arose from multiple hybridizations between Ae. markgrafii (Greuter) Hammer. and Ae. tauschii Coss. presumably along the Fertile Crescent, where the geographic distributions of its diploid progenitors overlap. However, the center of genetic diversity of this species now encompasses a larger area including northern Iraq, eastern Turkey, and Transcaucasia. Although the majority of accessions of Ae. cylindrica (87%) had D-type plastomes derived from Ae. tauschii, accessions with C-type plastomes (13%), derived from Ae. markgrafii, were also observed. This corroborates a previous study suggesting the dimaternal origin of Ae. cylindrica. Model-based and genetic distance-based clustering using both chloroplast and nuclear markers indicated that Ae. tauschii ssp. tauschii contributed one of its D-type plastomes and its D genome to Ae. cylindrica. Analysis of genetic structure using nuclear markers suggested that Ae. cylindrica accessions could be grouped into three subpopulations (arbitrarily named N-K1, N-K2, and N-K3). Members of the N-K1 subpopulation were the most numerous in its native range and members of the N-K2 subpopulation were the most common in the USA. Our analysis also indicated that Ae. cylindrica accessions in the USA were derived from a few founder genotypes. The frequency of Ae. cylindrica accessions with the C-type plastome in the USA (approximately 24%) was substantially higher than in its native range of distribution (approximately 3%) and all C-type Ae. cylindrica in the USA except one belonged to subpopulation N-K2. The high frequency of the C-type plastome in the USA may reflect a favorable nucleo-cytoplasmic combination. PMID:19618161

  17. Engineered Repressible Lethality for Controlling the Pink Bollworm, a Lepidopteran Pest of Cotton

    PubMed Central

    Morrison, Neil I.; Simmons, Gregory S.; Fu, Guoliang; O’Connell, Sinead; Walker, Adam S.; Dafa’alla, Tarig; Walters, Michelle; Claus, John; Tang, Guolei; Jin, Li; Marubbi, Thea; Epton, Matthew J.; Harris, Claire L.; Staten, Robert T.; Miller, Ernest; Miller, Thomas A.; Alphey, Luke

    2012-01-01

    The sterile insect technique (SIT) is an environmentally friendly method of pest control in which insects are mass-produced, irradiated and released to mate with wild counterparts. SIT has been used to control major pest insects including the pink bollworm (Pectinophora gossypiella Saunders), a global pest of cotton. Transgenic technology has the potential to overcome disadvantages associated with the SIT, such as the damaging effects of radiation on released insects. A method called RIDL (Release of Insects carrying a Dominant Lethal) is designed to circumvent the need to irradiate insects before release. Premature death of insects’ progeny can be engineered to provide an equivalent to sterilisation. Moreover, this trait can be suppressed by the provision of a dietary antidote. In the pink bollworm, we generated transformed strains using different DNA constructs, which showed moderate-to-100% engineered mortality. In permissive conditions, this effect was largely suppressed. Survival data on cotton in field cages indicated that field conditions increase the lethal effect. One strain, called OX3402C, showed highly penetrant and highly repressible lethality, and was tested on host plants where its larvae caused minimal damage before death. These results highlight a potentially valuable insecticide-free tool against pink bollworm, and indicate its potential for development in other lepidopteran pests. PMID:23226548

  18. Engineered repressible lethality for controlling the pink bollworm, a lepidopteran pest of cotton.

    PubMed

    Morrison, Neil I; Simmons, Gregory S; Fu, Guoliang; O'Connell, Sinead; Walker, Adam S; Dafa'alla, Tarig; Walters, Michelle; Claus, John; Tang, Guolei; Jin, Li; Marubbi, Thea; Epton, Matthew J; Harris, Claire L; Staten, Robert T; Miller, Ernest; Miller, Thomas A; Alphey, Luke

    2012-01-01

    The sterile insect technique (SIT) is an environmentally friendly method of pest control in which insects are mass-produced, irradiated and released to mate with wild counterparts. SIT has been used to control major pest insects including the pink bollworm (Pectinophora gossypiella Saunders), a global pest of cotton. Transgenic technology has the potential to overcome disadvantages associated with the SIT, such as the damaging effects of radiation on released insects. A method called RIDL (Release of Insects carrying a Dominant Lethal) is designed to circumvent the need to irradiate insects before release. Premature death of insects' progeny can be engineered to provide an equivalent to sterilisation. Moreover, this trait can be suppressed by the provision of a dietary antidote. In the pink bollworm, we generated transformed strains using different DNA constructs, which showed moderate-to-100% engineered mortality. In permissive conditions, this effect was largely suppressed. Survival data on cotton in field cages indicated that field conditions increase the lethal effect. One strain, called OX3402C, showed highly penetrant and highly repressible lethality, and was tested on host plants where its larvae caused minimal damage before death. These results highlight a potentially valuable insecticide-free tool against pink bollworm, and indicate its potential for development in other lepidopteran pests. PMID:23226548

  19. [Isolation and characterization of petroleum catabolic broad-host-range plasmids from Shen-Fu wastewater irrigation zone].

    PubMed

    Wang, Ya-Fei; Wang, Ya-Fei; Li, Hui; Li, Xiao-Bin

    2013-11-01

    Based on triparental mating, we isolated a total of eight broad host range (BHR) petroleum hydrocarbon catabolic plasmids from the soils, sediments, and wastewater samples in the Shen-Fu irrigation zone. The antibiotic resistance of the plasmids was tested, and then, the plasmids were transferred to Escherichia coli EC100. The plasmids carrying no antibiotic resistance were tagged by miniTn5 transposon consisting of antibiotic resistant genes. The PCR-based incompatibility test revealed that the pS3-2C and pS4-6G belonged to Inc P group, the pS3-2G, pW22-3G, and pA15-7G belonged to Inc N group, the pS7-2G was identified as Inc W plasmid, and the pA23-1G and pA10-1C were placed into Inc Q group. By adopting the reported PCR amplification methods of petroleum hydrocarbon-degrading catabolic genes, the petroleum-degrading capability of these BHR plasmids were preliminarily analyzed. The plasmids pS3-2G, pS7-2G, pA23-1G, pW22-3G, and pA10-1C carried aromatic ring- hydroxylating dioxygenase gene phdA and toluene monooxygenase gene touA; the plasmid pA15-7G carried touA and toluene dioxygenase gene tod; the plasmid pS3-2C carried ben, phdA, and tod; whereas the pS4-6G only carried ben. The host range test showed that all the isolated plasmids except pS3-2C could be transferred and maintained stably in the representative strains Agrobacterium tumefaciens C58, Cupriavidus necator JMP228, and E. coli EC100 of the alpha-, beta-, and gamma-Proteobacteria, respectively. PMID:24564162

  20. In-Silico Determination of Insecticidal Potential of Vip3Aa-Cry1Ac Fusion Protein Against Lepidopteran Targets Using Molecular Docking.

    PubMed

    Ahmad, Aftab; Javed, Muhammad R; Rao, Abdul Q; Khan, Muhammad A U; Ahad, Ammara; Din, Salah Ud; Shahid, Ahmad A; Husnain, Tayyab

    2015-01-01

    Study and research of Bt (Bacillus thuringiensis) transgenic plants have opened new ways to combat insect pests. Over the decades, however, insect pests, especially the Lepidopteran, have developed tolerance against Bt delta-endotoxins. Such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. In this computational study, functional domains of Bacillus thuringiensis crystal delta-endotoxin (Cry1Ac) insecticidal protein and vegetative insecticidal protein (Vip3Aa) have been fused to develop a broad-range Vip3Aa-Cry1Ac fusion protein. Cry1Ac and Vip3Aa are non-homologous insecticidal proteins possessing receptors against different targets within the midgut of insects. The insecticidal proteins were fused to broaden the insecticidal activity. Molecular docking analysis of the fusion protein against aminopeptidase-N (APN) and cadherin receptors of five Lepidopteran insects (Agrotis ipsilon, Helicoverpa armigera, Pectinophora gossypiella, Spodoptera exigua, and Spodoptera litura) revealed that the Ser290, Ser293, Leu337, Thr340, and Arg437 residues of the fusion protein are involved in the interaction with insect receptors. The Helicoverpa armigera cadherin receptor, however, showed no interaction, which might be due to either loss or burial of interactive residues inside the fusion protein. These findings revealed that the Vip3Aa-Cry1Ac fusion protein has a strong affinity against Lepidopteran insect receptors and hence has a potential to be an efficient broad-range insecticidal protein. PMID:26697037

  1. In-Silico Determination of Insecticidal Potential of Vip3Aa-Cry1Ac Fusion Protein Against Lepidopteran Targets Using Molecular Docking

    PubMed Central

    Ahmad, Aftab; Javed, Muhammad R.; Rao, Abdul Q.; Khan, Muhammad A. U.; Ahad, Ammara; Din, Salah ud; Shahid, Ahmad A.; Husnain, Tayyab

    2015-01-01

    Study and research of Bt (Bacillus thuringiensis) transgenic plants have opened new ways to combat insect pests. Over the decades, however, insect pests, especially the Lepidopteran, have developed tolerance against Bt delta-endotoxins. Such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. In this computational study, functional domains of Bacillus thuringiensis crystal delta-endotoxin (Cry1Ac) insecticidal protein and vegetative insecticidal protein (Vip3Aa) have been fused to develop a broad-range Vip3Aa-Cry1Ac fusion protein. Cry1Ac and Vip3Aa are non-homologous insecticidal proteins possessing receptors against different targets within the midgut of insects. The insecticidal proteins were fused to broaden the insecticidal activity. Molecular docking analysis of the fusion protein against aminopeptidase-N (APN) and cadherin receptors of five Lepidopteran insects (Agrotis ipsilon, Helicoverpa armigera, Pectinophora gossypiella, Spodoptera exigua, and Spodoptera litura) revealed that the Ser290, Ser293, Leu337, Thr340, and Arg437 residues of the fusion protein are involved in the interaction with insect receptors. The Helicoverpa armigera cadherin receptor, however, showed no interaction, which might be due to either loss or burial of interactive residues inside the fusion protein. These findings revealed that the Vip3Aa-Cry1Ac fusion protein has a strong affinity against Lepidopteran insect receptors and hence has a potential to be an efficient broad-range insecticidal protein. PMID:26697037

  2. Predicting the host range of Nystalea ebalea: secondary plant chemistry and host selection by a surrogate biological control agent of Schinus terebinthifolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The safety of weed biological control depends upon the selection and utilization of the target weed by the agent while causing minimal harm to non-target species. Selection of weed species by biological control agents is determined by the presence of behavioral cues, generally host secondary plant c...

  3. Host Range of a Population of Pratylenchus vulnus in Commercial Fruit, Nut, Citrus, and Grape Rootstocks in Spain.

    PubMed

    Pinochet, J; Verdejo, S; Soler, A; Canals, J

    1992-12-01

    In a host-range study carried out under greenhouse conditions, a total of 37 commercial fruit tree, grape, and citrus rootstocks were tested for their reaction to a population of the lesion nematode, Pratylenchus vulnus, in Spain. Twenty-five rootstocks had a Pf/Pi > 1.5. These included almond (Desmayo Rojo, 1143), apple (EM-9, EM-106), avocado (Hass), cherry (Santa Lucia 64, Camil, M x M 14, Masto de Montafiana), grape (41-B, Fercal, Ritcher 110), hazelnut (Pauetet), loquat (Nadal), peach (Montclar, GF-305), pear (OHF-333), pistachio (P. atlantica, P. vera, P. terebinthus), plum (San Julian 655-2, Montizo, Pixy, Myrobalan 605), and walnut (Serf). The peach rootstock Nemaguard and the grape 161-49 had Pf/Pi between 1.0 and 1.5 (slightly higher than inoculation level). All the tested citrus (Alemow, rough lemon, Carrizo citrange, sour orange, Troyer citrange, Citrumelo), plus three grape (SO4, Vitis rupestris, 1103-P), and the olive rootstock Arbequina had a Pf/Pi < 1.0. PMID:19283047

  4. Broad host range of human T-cell leukemia virus type 1 demonstrated with an improved pseudotyping system.

    PubMed Central

    Sutton, R E; Littman, D R

    1996-01-01

    Studies of human T-cell leukemia virus type 1 (HTLV-1) have been hampered by the difficulty of achieving high cell-free and cell-associated infectious titers. Current retroviral pseudotyping systems using the HTLV-1 envelope generate titers of less than 200 infectious particles per ml. We describe here an improved system for pseudotyping using a defective human immunodeficiency virus (HIV) type 1 genome in combination with HTLV-1 env in 293T producer cells. Introduction of additional copies of rev and treatment of cells with sodium butyrate resulted in a cell-associated titer of 10(5)/ml and cell-free titers of greater than 10(4)/ml . By using this system, we found that the host range of HTLV-1 is even greater than previously suspected. Earlier studies which assigned a chromosomal location for the HTLV-1 receptor may therefore reflect cell-to-cell variation in receptor number rather than the absolute presence or absence of a receptor. The generation of higher-titer HIV(HTLV-1) may facilitate identification of the cellular receptor and investigations of the pathophysiology of HTLV-1 infection. PMID:8794391

  5. Development and Use of a Selectable, Broad-Host-Range Reporter Transposon for Identifying Environmentally Regulated Promoters in Bacteria

    PubMed Central

    Spinler, Jennifer K.; Zajdowicz, Sheryl L. W.; Haller, Jon C.; Oram, Diana Marra; Gill, Ronald E.; Holmes, Randall K.

    2009-01-01

    This report describes the development and use of TnKnXSp, a selectable broad-host-range reporter transposon with a promoterless aphA gene. Insertion of TnKnXSp into the chromosome of a kanamycin-susceptible bacterium confers resistance to kanamycin only if aphA is transcribed from an active promoter adjacent to the insertion site. We designed TnKnXSp as a tool for identifying environmentally regulated promoters in bacteria and developed general methods for initial characterization of any TnKnXSp integrant. To identify putative iron-regulated promoters in Corynebacterium diphtheriae, we constructed TnKnXSp integrants and identified a subgroup that expressed kanamycin resistance under low-iron, but not high-iron, conditions. We characterized representative integrants with this phenotype, located the TnKnXSp insertion in each, and demonstrated that transcription of aphA was repressed under high-iron vs. low-iron growth conditions. We also demonstrated that TnKnXSp can be used in bacteria other than C. diphtheriae, including Escherichia coli and Bacillus subtilus. Our findings validate TnKnXSp as a useful tool for identifying environmentally regulated promoters in bacteria. PMID:19146571

  6. Broad-Host-Range Yersinia Phage PY100: Genome Sequence, Proteome Analysis of Virions, and DNA Packaging Strategy▿

    PubMed Central

    Schwudke, Dominik; Ergin, Asgar; Michael, Kathrin; Volkmar, Sven; Appel, Bernd; Knabner, Dorothea; Konietzny, Antje; Strauch, Eckhard

    2008-01-01

    PY100 is a lytic bacteriophage with a broad host range within the genus Yersinia. The phage forms plaques on strains of the three human pathogenic species Yersinia enterocolitica, Y. pseudotuberculosis, and Y. pestis at 37°C. PY100 was isolated from farm manure and intended to be used in phage therapy trials. PY100 has an icosahedral capsid containing double-stranded DNA and a contractile tail. The genome consists of 50,291 bp and is predicted to contain 93 open reading frames (ORFs). PY100 gene products were found to be homologous to the capsid proteins and proteins involved in DNA metabolism of the enterobacterial phage T1; PY100 tail proteins possess homologies to putative tail proteins of phage AaΦ23 of Actinobacillus actinomycetemcomitans. In a proteome analysis of virion particles, 15 proteins of the head and tail structures were identified by mass spectrometry. The putative gene product of ORF2 of PY100 shows significant homology to the gene 3 product (small terminase subunit) of Salmonella phage P22 that is involved in packaging of the concatemeric phage DNA. The packaging mechanism of PY100 was analyzed by hybridization and sequence analysis of DNA isolated from virion particles. Newly replicated PY100 DNA is cut initially at a pac recognition site, which is located in the coding region of ORF2. PMID:17965162

  7. A chimeolysin with extended-spectrum streptococcal host range found by an induced lysis-based rapid screening method

    PubMed Central

    Yang, Hang; Linden, Sara B.; Wang, Jing; Yu, Junping; Nelson, Daniel C.; Wei, Hongping

    2015-01-01

    The increasing emergence of multi-drug resistant streptococci poses a serious threat to public health worldwide. Bacteriophage lysins are promising alternatives to antibiotics; however, their narrow lytic spectrum restricted to closely related species is a central shortcoming to their translational development. Here, we describe an efficient method for rapid screening of engineered chimeric lysins and report a unique “chimeolysin”, ClyR, with robust activity and an extended-spectrum streptococcal host range against most streptococcal species, including S. pyogenes, S. agalactiae, S. dysgalactiae, S. equi, S. mutans, S. pneumoniae, S. suis and S. uberis, as well as representative enterococcal and staphylococcal species (including MRSA and VISA). ClyR is the first lysin that demonstrates activity against the dominant dental caries-causing pathogen as well as the first lysin that kills all four of the bovine mastitis-causing pathogens. This study demonstrates the success of the screening method resulting in a powerful lysin with potential for treating most streptococcal associated infections. PMID:26607832

  8. Host Range of Small-Ruminant Lentivirus Cytopathic Variants Determined with a Selectable Caprine Arthritis- Encephalitis Virus Pseudotype System

    PubMed Central

    Hötzel, Isidro; Cheevers, William P.

    2001-01-01

    The small-ruminant lentiviruses ovine maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) cause encephalitis, progressive pneumonia, arthritis, and mastitis in sheep and goats. Icelandic MVV strains, which are lytic in tissue culture, have a wide species distribution of functional receptors, which includes human cells. In contrast, functional receptors for the nonlytic CAEV CO are absent from human cells. To determine if the wide species distribution of functional receptors is a common property of MVV strains or related to cytopathic phenotype, we tested the infectivity of viruses pseudotyped with the envelope glycoproteins of MVV K1514, CAEV CO, and lytic and nonlytic North American MVV strains to cells of different species. Replication-defective CAEV proviral constructs lacking the env, tat, and vif genes and carrying the neomycin phosphotransferase gene in the vif-tat region were developed for the infectivity assays. Cotransfection of human 293T cells with these proviral constructs and plasmids expressing CAEV, MVV, or vesicular stomatitis virus envelope glycoproteins produced infectious pseudotyped virus which induced resistance of infected cells to G418. Using these pseudotypes, we confirmed the wide species distribution of Icelandic MVV receptors and the narrow host range of CAEV. However, functional receptors for the two North American MVV strains tested, unlike the Icelandic MVV and similar to CAEV, were limited to cells of ruminant species, regardless of cytopathic phenotype. The results indicate a differential receptor recognition by MVV strains which is unrelated to cytopathic phenotype. PMID:11462010

  9. Comparative Analysis of Chlamydia psittaci Genomes Reveals the Recent Emergence of a Pathogenic Lineage with a Broad Host Range

    PubMed Central

    Read, Timothy D.; Joseph, Sandeep J.; Didelot, Xavier; Liang, Brooke; Patel, Lisa; Dean, Deborah

    2013-01-01

    ABSTRACT Chlamydia psittaci is an obligate intracellular bacterium. Interest in Chlamydia stems from its high degree of virulence as an intestinal and pulmonary pathogen across a broad range of animals, including humans. C. psittaci human pulmonary infections, referred to as psittacosis, can be life-threatening, which is why the organism was developed as a bioweapon in the 20th century and is listed as a CDC biothreat agent. One remarkable recent result from comparative genomics is the finding of frequent homologous recombination across the genome of the sexually transmitted and trachoma pathogen Chlamydia trachomatis. We sought to determine if similar evolutionary dynamics occurred in C. psittaci. We analyzed 20 C. psittaci genomes from diverse strains representing the nine known serotypes of the organism as well as infections in a range of birds and mammals, including humans. Genome annotation revealed a core genome in all strains of 911 genes. Our analyses showed that C. psittaci has a history of frequently switching hosts and undergoing recombination more often than C. trachomatis. Evolutionary history reconstructions showed genome-wide homologous recombination and evidence of whole-plasmid exchange. Tracking the origins of recombinant segments revealed that some strains have imported DNA from as-yet-unsampled or -unsequenced C. psittaci lineages or other Chlamydiaceae species. Three ancestral populations of C. psittaci were predicted, explaining the current population structure. Molecular clock analysis found that certain strains are part of a clonal epidemic expansion likely introduced into North America by South American bird traders, suggesting that psittacosis is a recently emerged disease originating in New World parrots. PMID:23532978

  10. Comparative analysis of Chlamydia psittaci genomes reveals the recent emergence of a pathogenic lineage with a broad host range.

    PubMed

    Read, Timothy D; Joseph, Sandeep J; Didelot, Xavier; Liang, Brooke; Patel, Lisa; Dean, Deborah

    2013-01-01

    Chlamydia psittaci is an obligate intracellular bacterium. Interest in Chlamydia stems from its high degree of virulence as an intestinal and pulmonary pathogen across a broad range of animals, including humans. C. psittaci human pulmonary infections, referred to as psittacosis, can be life-threatening, which is why the organism was developed as a bioweapon in the 20th century and is listed as a CDC biothreat agent. One remarkable recent result from comparative genomics is the finding of frequent homologous recombination across the genome of the sexually transmitted and trachoma pathogen Chlamydia trachomatis. We sought to determine if similar evolutionary dynamics occurred in C. psittaci. We analyzed 20 C. psittaci genomes from diverse strains representing the nine known serotypes of the organism as well as infections in a range of birds and mammals, including humans. Genome annotation revealed a core genome in all strains of 911 genes. Our analyses showed that C. psittaci has a history of frequently switching hosts and undergoing recombination more often than C. trachomatis. Evolutionary history reconstructions showed genome-wide homologous recombination and evidence of whole-plasmid exchange. Tracking the origins of recombinant segments revealed that some strains have imported DNA from as-yet-unsampled or -unsequenced C. psittaci lineages or other Chlamydiaceae species. Three ancestral populations of C. psittaci were predicted, explaining the current population structure. Molecular clock analysis found that certain strains are part of a clonal epidemic expansion likely introduced into North America by South American bird traders, suggesting that psittacosis is a recently emerged disease originating in New World parrots. PMID:23532978

  11. Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador.

    PubMed

    Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C Miguel; Vallejo, Gustavo A; Grijalva, Mario J

    2015-12-01

    Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(-)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru. PMID:26645579

  12. The biology and preliminary host range of Megacopta cribraria (Heteroptera: Plataspidae) and its impact on kudzu growth.

    PubMed

    Zhang, Yanzhuo; Hanula, James L; Horn, Scott

    2012-02-01

    The bean plataspid, Megacopta cribraria (F.), recently was discovered in the United States feeding on kudzu, Pueraria montana Lour. (Merr.) variety lobata (Willd.), an economically important invasive vine. We studied its biology on kudzu and its impact on kudzu growth. We also tested its ability to use other common forest legumes for oviposition and development. Flight intercept traps operated from 17 May 2010 to 31 May 2011 in a kudzu field near Athens, GA showed three peaks of adult flight activity suggesting there are two generations per year on kudzu. Vine samples examined for eggs from April 2010 to April 2011 and June to October 2011 showed two periods of oviposition activity in 2010, which coincided with the peaks in adult activity. In 2011, the second period of oviposition began on or before 24 June and then egg abundance declined gradually thereafter until late August when we recovered <2 eggs/0.5 m of vine. Samples of the five nymphal instars and adults on vines did not show similar trends in abundance. Adults did not lay eggs on the various legume species tested in 2010 in a no-choice test possibly because the cages were too small. In the 2011 field host range experiments conducted in a kudzu field by using 12 legume species, M. cribraria preferentially oviposited on kudzu over soybean, Glycine max Merrill., but they still laid 320 eggs per plant on soybean. Lespedeza hirta (L.) Hornem. and Lespedeza cuneata (Dum. Cours.) G. Don had 122.2 and 108.4 eggs per plant, respectively. Kudzu and soybean were the only species M. cribraria completed development on. Plots protected from M. cribraria feeding by biweekly insecticide applications had 32.8% more kudzu biomass than unprotected plots. Our results show that M. cribraria has a significant impact on kudzu growth and could help suppress this pest weed. PMID:22525058

  13. Diagnosis of a new variant of soybean yellow mottle mosaic virus with extended host-range in India.

    PubMed

    Sandra, Nagamani; Kumar, Alok; Sharma, Prachi; Kapoor, Reetika; Jain, Rakesh Kumar; Mandal, Bikash

    2015-12-01

    Soybean yellow mottle mosaic virus (SYMMV, genus Carmovirus) was previously known to occur in South Korea and USA causing bright yellow mosaic in soybean. In this study, SYMMV (Car-Mb14 isolate) was isolated from mungbean (Vigna radiata) exhibiting mild mottling and puckering symptoms in the experimental field at Indian Agricultural Research Institute, New Delhi during 2012. The virus isolate, Car-Mb14 induced veinal mottling, mild mottling, chlorotic blotching, local and systemic necrosis in soybean, mungbean, blackgram, French bean and guar bean, respectively. The symptomatology of the present isolate of SYMMV was different from the previously reported South Korean isolate, as the later did not induce symptoms in any of the above legumes other than soybean. The present isolate was phylogenetically distinct and shared 90-93 % sequence identity in coat protein (CP) of 52 SYMMV isolates reported from Korea and USA. In order to know the serological relationships, the CP gene of the present isolate was over expressed as a 39 kDa protein in E. coli and an antiserum of 1:16,000 titer against the recombinant CP was produced. Serological cross reactivity analysis revealed that SYMMV was serologically related to blackgram mottle virus but not to cowpea mottle virus, the other legume infecting carmoviruses. The antiserum was used to detect prevalence of SYMMV in legume crops by ELISA. Out of 145 field samples of legumes (mungbean, blackgram, French bean and soybean) collected from different places in India, SYMMV was detected only in 16 samples of mungbean and one sample of blackgram. The natural infection of SYMMV in mungbean and blackgram was further confirmed based on CP gene sequence. This study provides evidence of occurrence of a new variant of SYMMV with distinct symptom phenotype and extended host-range in India. PMID:26645042

  14. Lepidopteran cells, an alternative for the production of recombinant antibodies?

    PubMed Central

    Cérutti, Martine; Golay, Josée

    2012-01-01

    Monoclonal antibodies are used with great success in many different therapeutic domains. In order to satisfy the growing demand and to lower the production cost of these molecules, many alternative systems have been explored. Among them, the baculovirus/insect cells system is a good candidate. This system is very safe, given that the baculoviruses have a highly restricted host range and they are not pathogenic to vertebrates or plants. But the major asset is the speed with which it is possible to obtain very stable recombinant viruses capable of producing fully active proteins whose glycosylation pattern can be modulated to make it similar to the human one. These features could ultimately make the difference by enabling the production of antibodies with very low costs. However, efforts are still needed, in particular to increase production rates and thus make this system commercially viable for the production of these therapeutic agents. PMID:22531440

  15. Structure of the lepidopteran proboscis in relation to feeding guild.

    PubMed

    Lehnert, Matthew S; Beard, Charles E; Gerard, Patrick D; Kornev, Konstantin G; Adler, Peter H

    2016-02-01

    Most butterflies and moths (Lepidoptera) use modified mouthparts, the proboscis, to acquire fluids. We quantified the proboscis architecture of five butterfly species in three families to test the hypothesis that proboscis structure relates to feeding guild. We used scanning electron microscopy to elucidate the fine structure of the proboscis of both sexes and to quantify dimensions, cuticular patterns, and the shapes and sizes of sensilla and dorsal legulae. Sexual dimorphism was not detected in the proboscis structure of any species. A hierarchical clustering analysis of overall proboscis architecture reflected lepidopteran phylogeny, but did not produce a distinct group of flower visitors or of puddle visitors within the flower visitors. Specific characters of the proboscis, nonetheless, can indicate flower and nonflower visitors, such as the configuration of sensilla styloconica, width of the lower branches of dorsal legulae, presence or absence of dorsal legulae at the extreme apex, and degree of proboscis tapering. We suggest that the overall proboscis architecture of Lepidoptera reflects a universal structural organization that promotes fluid uptake from droplets and films. On top of this fundamental structural organization, we suggest that the diversity of floral structure has selected for structural adaptations that facilitate entry of the proboscis into floral tubes. PMID:26589780

  16. Myxoma virus M064 is a novel member of the poxvirus C7L superfamily of host range factors that controls the kinetics of myxomatosis in European rabbits.

    PubMed

    Liu, Jia; Wennier, Sonia; Moussatche, Nissin; Reinhard, Mary; Condit, Richard; McFadden, Grant

    2012-05-01

    The myxoma virus (MYXV) carries three tandem C7L-like host range genes (M062R, M063R, and M064R). However, despite the fact that the sequences of these three genes are similar, they possess very distinctive functions in vivo. The role of M064 in MYXV pathogenesis was investigated and compared to the roles of M062 and M063. We report that M064 is a virulence factor that contributes to MYXV pathogenesis but lacks the host range properties associated with M062 and M063. PMID:22379095

  17. Single Mutations in the VP2 300 Loop Region of the Three-Fold Spike of the Carnivore Parvovirus Capsid Can Determine Host Range

    PubMed Central

    Organtini, Lindsey J.; Zhang, Sheng; Hafenstein, Susan L.; Holmes, Edward C.

    2015-01-01

    ABSTRACT Sylvatic carnivores, such as raccoons, have recently been recognized as important hosts in the evolution of canine parvovirus (CPV), a pandemic pathogen of domestic dogs. Although viruses from raccoons do not efficiently bind the dog transferrin receptor (TfR) or infect dog cells, a single mutation changing an aspartic acid to a glycine at capsid (VP2) position 300 in the prototype raccoon CPV allows dog cell infection. Because VP2 position 300 exhibits extensive amino acid variation among the carnivore parvoviruses, we further investigated its role in determining host range by analyzing its diversity and evolution in nature and by creating a comprehensive set of VP2 position 300 mutants in infectious clones. Notably, some position 300 residues rendered CPV noninfectious for dog, but not cat or fox, cells. Changes of adjacent residues (residues 299 and 301) were also observed often after cell culture passage in different hosts, and some of the mutations mimicked changes seen in viruses recovered from natural infections of alternative hosts, suggesting that compensatory mutations were selected to accommodate the new residue at position 300. Analysis of the TfRs of carnivore hosts used in the experimental evolution studies demonstrated that their glycosylation patterns varied, including a glycan present only on the domestic dog TfR that dictates susceptibility to parvoviruses. Overall, there were significant differences in the abilities of viruses with alternative position 300 residues to bind TfRs and infect different carnivore hosts, demonstrating that the process of infection is highly host dependent and that VP2 position 300 is a key determinant of host range. IMPORTANCE Although the emergence and pandemic spread of canine parvovirus (CPV) are well documented, the carnivore hosts and evolutionary pathways involved in its emergence remain enigmatic. We recently demonstrated that a region in the capsid structure of CPV, centered around VP2 position 300

  18. Tick infestation patterns in free ranging African buffalo (Syncercus caffer): Effects of host innate immunity and niche segregation among tick species☆

    PubMed Central

    Anderson, Kadie; Ezenwa, Vanessa O.; Jolles, Anna E.

    2012-01-01

    Ticks are of vast importance to livestock health, and contribute to conflicts between wildlife conservation and agricultural interests; but factors driving tick infestation patterns on wild hosts are not well understood. We studied tick infestation patterns on free-ranging African buffalo (Syncercus caffer), asking (i) is there evidence for niche segregation among tick species?; and (ii) how do host characteristics affect variation in tick abundance among hosts? We identified ticks and estimated tick burdens on 134 adult female buffalo from two herds at Kruger National Park, South Africa. To assess niche segregation, we evaluated attachment site preferences and tested for correlations between abundances of different tick species. To investigate which host factors may drive variability in tick abundance, we measured age, body condition, reproductive and immune status in all hosts, and examined their effects on tick burdens. Two tick species were abundant on buffalo, Amblyomma hebraeum and Rhipicephalus evertsi evertsi. A. hebraeum were found primarily in the inguinal and axillary regions; R. e. evertsi attached exclusively in the perianal area. Abundances of A. hebraeum and R. e. evertsi on the host were unrelated. These results suggest spatial niche segregation between A. hebraeum and R. e. evertsi on the buffalo. Buffalo with stronger innate immunity, and younger buffalo, had fewer ticks. Buffalo with low body condition scores, and pregnant buffalo, had higher tick burdens, but these effects varied between the two herds we sampled. This study is one of the first to link ectoparasite abundance patterns and immunity in a free-ranging mammalian host population. Based on independent abundances of A. hebraeum and R. e. evertsi on individual buffalo, we would expect no association between the diseases these ticks transmit. Longitudinal studies linking environmental variability with host immunity are needed to understand tick infestation patterns and the dynamics of tick

  19. Tick infestation patterns in free ranging African buffalo (Syncercus caffer): Effects of host innate immunity and niche segregation among tick species.

    PubMed

    Anderson, Kadie; Ezenwa, Vanessa O; Jolles, Anna E

    2013-12-01

    Ticks are of vast importance to livestock health, and contribute to conflicts between wildlife conservation and agricultural interests; but factors driving tick infestation patterns on wild hosts are not well understood. We studied tick infestation patterns on free-ranging African buffalo (Syncercus caffer), asking (i) is there evidence for niche segregation among tick species?; and (ii) how do host characteristics affect variation in tick abundance among hosts? We identified ticks and estimated tick burdens on 134 adult female buffalo from two herds at Kruger National Park, South Africa. To assess niche segregation, we evaluated attachment site preferences and tested for correlations between abundances of different tick species. To investigate which host factors may drive variability in tick abundance, we measured age, body condition, reproductive and immune status in all hosts, and examined their effects on tick burdens. Two tick species were abundant on buffalo, Amblyomma hebraeum and Rhipicephalus evertsi evertsi. A. hebraeum were found primarily in the inguinal and axillary regions; R. e. evertsi attached exclusively in the perianal area. Abundances of A. hebraeum and R. e. evertsi on the host were unrelated. These results suggest spatial niche segregation between A. hebraeum and R. e. evertsi on the buffalo. Buffalo with stronger innate immunity, and younger buffalo, had fewer ticks. Buffalo with low body condition scores, and pregnant buffalo, had higher tick burdens, but these effects varied between the two herds we sampled. This study is one of the first to link ectoparasite abundance patterns and immunity in a free-ranging mammalian host population. Based on independent abundances of A. hebraeum and R. e. evertsi on individual buffalo, we would expect no association between the diseases these ticks transmit. Longitudinal studies linking environmental variability with host immunity are needed to understand tick infestation patterns and the dynamics of tick

  20. Bacteria influence mountain pine beetle brood development through interactions with symbiotic and antagonistic fungi: implications for climate-driven host range expansion.

    PubMed

    Therrien, Janet; Mason, Charles J; Cale, Jonathan A; Adams, Aaron; Aukema, Brian H; Currie, Cameron R; Raffa, Kenneth F; Erbilgin, Nadir

    2015-10-01

    Bark beetles are associated with diverse communities of symbionts. Although fungi have received significant attention, we know little about how bacteria, and in particular their interactions with fungi, affect bark beetle reproduction. We tested how interactions between four bacterial associates, two symbiotic fungi, and two opportunistic fungi affect performance of mountain pine beetles (Dendroctonus ponderosae) in host tissue. We compared beetle performance in phloem of its historical host, lodgepole pine (Pinus contorta), and its novel host recently accessed through warming climate, jack pine (Pinus banksiana). Overall, beetles produced more larvae, and established longer ovipositional and larval galleries in host tissue predominantly colonized by the symbiotic fungi, Grosmannia clavigera, or Ophiostoma montium than by the opportunistic colonizer Aspergillus and to a lesser extent, Trichoderma. This occurred in both historical and naïve hosts. Impacts of bacteria on beetle reproduction depended on particular fungus-bacterium combinations and host species. Some bacteria, e.g., Pseudomonas sp. D4-22 and Hy4T4 in P. contorta and Pseudomonas sp. Hy4T4 and Stenotrophomonas in P. banksiana, reduced antagonistic effects by Aspergillus and Trichoderma resulting in more larvae and longer ovipositional and larval galleries. These effects were not selective, as bacteria also reduced beneficial effects by symbionts in both host species. Interestingly, Bacillus enhanced antagonistic effects by Aspergillus in both hosts. These results demonstrate that bacteria influence brood development of bark beetles in host tissue. They also suggest that climate-driven range expansion of D. ponderosae through the boreal forest will not be significantly constrained by requirements of, or interactions among, its microbial associates. PMID:26037523

  1. Life history and host range of the leaf blotcher Eucosmophora schinusivora; a candidate for biological control of Schinus terebinthifolius in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The host range of Eucosmophora schinusivora Davis & Wheeler (Lepidoptera: Gracillariidae) was studied to assess its suitability as a biological control agent of Schinus terebinthifolius Raddi (Anacardiaceae), a serious environmental and agricultural weed in the USA and elsewhere in the world. The l...

  2. Host range testing and biology of Abia sericea (Cimbicidae), a candidate for biological control of invasive teasels (Dipsacus spp.) in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive teasels (Dipsacus spp., Dipsacaceae) are widespread in the USA, being present in 43 states and listed as noxious in five. The cimbicid sawfly Abia sericea (L.) is under evaluation as a potential agent for biological control of teasels. The host range, biology, and life history of this ins...

  3. Investigation of Host Range, Infectivity, and Spread of Turnip Vein Clearing Virus and a Possible Mechanism for Non-Seed Transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study we investigated the host range, transmission and symptom development of TVCV in several species of plants, as a step toward developing management strategy against seed transmissible viruses. While several species of plants failed to show symptoms of TVCV infection, we report that bush ...

  4. Slow cell infection, inefficient primary infection and inability to replicate in fat body determine host-range of Thysanoplusia orichalcea M Nucleopolyhedrovirus (ThorMNPV)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An enhanced green fluorescence protein (EGFP) gene expression cassette was inserted at the gp37 locus of Thysanoplusia orichacea M nucleopolyhedrovirus (ThorMNPV) to produce vThGFP to study host-range mechanisms. Using EGFP to monitor infection in vitro, many cell lines showed EGFP expression sugges...

  5. Extended geographical distribution and host range of the cactus moth Cactoblastis cactorum (Lepidoptera Pyralidae)in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field exploration was conducted to confirm the southernmost distribution of Cactoblastis cactorum in Argentina. The distribution of the moth was extended to the south (40° 10´S) and west (66° 56´W). The native Opuntia penicilligera was recorded as a host for the first time. These findings should ...

  6. Characterization and host range of the symbiotic fungus Fusarium euwallaceae sp. nov., vectored by the invasive ambrosia beetle Euwallacea sp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel symbiotic Fusarium euwallaceae fungus that serves as a specific nutritional source for the invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) is farmed in the galleries of host plants. This beetle-fungus complex, which has invaded Israel and California, is clo...

  7. Comparative Studies of Lepidopteran Baculovirus-Specific Protein FP25K: Development of a Novel Bombyx mori Nucleopolyhedrovirus-Based Vector with a Modified fp25K Gene▿

    PubMed Central

    Nakanishi, Tadashi; Goto, Chie; Kobayashi, Michihiro; Kang, WonKyung; Suzuki, Takehiro; Dohmae, Naoshi; Matsumoto, Shogo; Shimada, Toru; Katsuma, Susumu

    2010-01-01

    Lepidopteran baculovirus-specific protein FP25K performs many roles during the infection cycle, including functions in the production of occlusion bodies (OBs) and budded viruses (BVs), oral infection, and postmortem host degradation. To explore the common and specific functions of FP25K proteins among lepidopteran baculoviruses, we performed comparative analyses of FP25K proteins from group I and group II nucleopolyhedroviruses (NPVs) and granulovirus (GV). Using recombinant Bombyx mori NPVs (BmNPVs), we showed that the FP25Ks from NPVs were able to eliminate all the phenotypic defects observed in an infection with a BmNPV mutant lacking functional fp25K but that FP25K from GV did not show abilities to recover oral infectivity and postmortem host degradation. We also observed that introduction of Autographa californica multiple NPV (AcMNPV) fp25K into the BmNPV genome enhanced OB and BV production. According to these results, we generated a novel BmNPV-based expression vector with AcMNPV fp25K and examined its potential in BmN cells and B. mori larvae. Our results showed that the introduction of AcMNPV fp25K significantly increases the expression of foreign gene products in cultured cells and shortens the time for obtaining the secreted recombinant proteins from larval hemolymph. PMID:20219904

  8. Computational and Functional Analysis of the Virus-Receptor Interface Reveals Host Range Trade-Offs in New World Arenaviruses

    PubMed Central

    Kerr, Scott A.; Jackson, Eleisha L.; Lungu, Oana I.; Meyer, Austin G.; Demogines, Ann; Ellington, Andrew D.; Georgiou, George

    2015-01-01

    ABSTRACT Animal viruses frequently cause zoonotic disease in humans. As these viruses are highly diverse, evaluating the threat that they pose remains a major challenge, and efficient approaches are needed to rapidly predict virus-host compatibility. Here, we develop a combined computational and experimental approach to assess the compatibility of New World arenaviruses, endemic in rodents, with the host TfR1 entry receptors of different potential new host species. Using signatures of positive selection, we identify a small motif on rodent TfR1 that conveys species specificity to the entry of viruses into cells. However, we show that mutations in this region affect the entry of each arenavirus differently. For example, a human single nucleotide polymorphism (SNP) in this region, L212V, makes human TfR1 a weaker receptor for one arenavirus, Machupo virus, but a stronger receptor for two other arenaviruses, Junin and Sabia viruses. Collectively, these findings set the stage for potential evolutionary trade-offs, where natural selection for resistance to one virus may make humans or rodents susceptible to other arenavirus species. Given the complexity of this host-virus interplay, we propose a computational method to predict these interactions, based on homology modeling and computational docking of the virus-receptor protein-protein interaction. We demonstrate the utility of this model for Machupo virus, for which a suitable cocrystal structural template exists. Our model effectively predicts whether the TfR1 receptors of different species will be functional receptors for Machupo virus entry. Approaches such at this could provide a first step toward computationally predicting the “host jumping” potential of a virus into a new host species. IMPORTANCE We demonstrate how evolutionary trade-offs may exist in the dynamic evolutionary interplay between viruses and their hosts, where natural selection for resistance to one virus could make humans or rodents susceptible

  9. Monitoring the Dissemination of the Broad-Host-Range Plasmid pB10 in Sediment Microcosms by Quantitative PCR▿ †

    PubMed Central

    Bonot, Sébastien; Merlin, Christophe

    2010-01-01

    Studying the transfer of specific mobile genetic elements in complex environmental matrices remains difficult because suitable molecular tools are not yet available to back up classical culture-dependent approaches. In this report, we show that quantitative PCR could be used to monitor the dissemination of the broad-host-range plasmid pB10 in sediment microcosms. This approach lies in the differential measurement of the host and plasmid DNAs used to inoculate the microcosms, using a particular design of quantitative PCR primers/probes where we took advantage of the mosaic aspect of the bacterial genomes to achieve a highly specific quantitative PCR detection system. PMID:19897757

  10. Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range.

    PubMed

    Henderson, Gemma; Cox, Faith; Ganesh, Siva; Jonker, Arjan; Young, Wayne; Janssen, Peter H

    2015-01-01

    Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific. PMID:26449758