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Sample records for serotype mating type

  1. Diploids in the Cryptococcus neoformans Serotype A Population Homozygous for the α Mating Type Originate via Unisexual Mating

    PubMed Central

    Lin, Xiaorong; Patel, Sweta; Litvintseva, Anastasia P.; Floyd, Anna; Mitchell, Thomas G.; Heitman, Joseph

    2009-01-01

    The ubiquitous environmental human pathogen Cryptococcus neoformans is traditionally considered a haploid fungus with a bipolar mating system. In nature, the α mating type is overwhelmingly predominant over a. How genetic diversity is generated and maintained by this heterothallic fungus in a largely unisexual α population is unclear. Recently it was discovered that C. neoformans can undergo same-sex mating under laboratory conditions generating both diploid intermediates and haploid recombinant progeny. Same-sex mating (α-α) also occurs in nature as evidenced by the existence of natural diploid αADα hybrids that arose by fusion between two α cells of different serotypes (A and D). How significantly this novel sexual style contributes to genetic diversity of the Cryptococcus population was unknown. In this study, ∼500 natural C. neoformans isolates were tested for ploidy and close to 8% were found to be diploid by fluorescence flow cytometry analysis. The majority of these diploids were serotype A isolates with two copies of the α MAT locus allele. Among those, several are intra-varietal allodiploid hybrids produced by fusion of two genetically distinct α cells through same-sex mating. The majority, however, are autodiploids that harbor two seemingly identical copies of the genome and arose via either endoreplication or clonal mating. The diploids identified were isolated from different geographic locations and varied genotypically and phenotypically, indicating independent non-clonal origins. The present study demonstrates that unisexual mating produces diploid isolates of C. neoformans in nature, giving rise to populations of hybrids and mixed ploidy. Our findings underscore the importance of same-sex mating in shaping the current population structure of this important human pathogenic fungus, with implications for mechanisms of selfing and inbreeding in other microbial pathogens. PMID:19180236

  2. Cryptococcus neoformans/Cryptococcus gattii species complex in southern Italy: an overview on the environmental diffusion of serotypes, genotypes and mating-types.

    PubMed

    Romeo, Orazio; Scordino, Fabio; Chillemi, Valeria; Criseo, Giuseppe

    2012-10-01

    Given the lack of comprehensive molecular epidemiology studies in Reggio Calabria and Messina, Italy, we decided to perform an extensive environmental sampling to describe the current molecular epidemiology of C. neoformans/C. gattii species complex in southern Italy. In this study, we report the occurrence of serotypes, genotypes and mating-types of isolates of the C. neoformans/C. gattii species complex recovered from environmental sources. In addition, a number of environmental C. neoformans var. grubii strains, isolated in 1997 by our laboratory, were also retrospectively examined in order to compare their genotypes with those recently found and to infer the possible epidemiological changes in our country. One hundred and twenty-two isolates were identified as being C. neoformans, whereas only one was found to belong to C. gattii serotype B, genotype VGI and mating-type alpha. Our data revealed that all environmental isolates of C. neoformans recovered here as well as those previously isolated in 1997 belong to serotype A and genotype VNI and posses a mating-type alpha allele.

  3. Prevalence, serotypes and mating patterns of Cryptococcus neoformans in the pellets of different avifauna in Madras, India.

    PubMed

    Gokulshankar, S; Ranganathan, S; Ranjith, M S; Ranjithsingh, A J A

    2004-08-01

    A total of 887 pellets of different avifauna were screened for the presence of Cryptococcus neoformans. One hundred and six of 887 samples (12%) yielded Cr. neoformans in culture. The report on the isolation of Cr. neoformans from the pellets of the crow appears to be new and of greater significance because of the ubiquitous prevalence of this bird in India. The prevalence of both MAT a and MAT alpha mating types were recorded. The serotype D was predominant over serotype A. The findings of the present study reveal the growing diverse ecological niche of Cr. neoformans in a the pellets of various avifauna in India.

  4. Cryptococcus gattii sero-mating type allelic pattern determined by multiplex PCR.

    PubMed

    Cogliati, M; D'Amicis, R; Tortorano, A M

    2015-02-01

    Molecular methods to differentiate serotypes, mating types and molecular types of Cryptococcus neoformans and C. gattii are important tools to understand epidemiology and pathogenesis of these pathogens. In this study, a multiplex polymerase chain reaction (PCR) approach was applied to sero-mating typing of C. gattii strains. Four pairs of primers were designed to target 4 allele-specific genes located in the mating-type locus. Twenty-three C. gattii strains, presenting different mating types and serotypes, were tested to validate the method. The method was able to identify all sero-mating allelic patterns including hybrid combinations, and therefore, it represents a simple one-step PCR for sero-mating typing of C. gattii strains.

  5. The evolution of mating type switching

    PubMed Central

    Hadjivasiliou, Zena; Pomiankowski, Andrew; Kuijper, Bram

    2016-01-01

    Predictions about the evolution of sex determination mechanisms have mainly focused on animals and plants, whereas unicellular eukaryotes such as fungi and ciliates have received little attention. Many taxa within the latter groups can stochastically switch their mating type identity during vegetative growth. Here, we investigate the hypothesis that mating type switching overcomes distortions in the distribution of mating types due to drift during asexual growth. Using a computational model, we show that smaller population size, longer vegetative periods and more mating types lead to greater distortions in the distribution of mating types. However, the impact of these parameters on optimal switching rates is not straightforward. We find that longer vegetative periods cause reductions and considerable fluctuations in the switching rate over time. Smaller population size increases the strength of selection for switching but has little impact on the switching rate itself. The number of mating types decreases switching rates when gametes can freely sample each other, but increases switching rates when there is selection for speedy mating. We discuss our results in light of empirical work and propose new experiments that could further our understanding of sexuality in isogamous eukaryotes. PMID:27271362

  6. Basidiomycete Mating Type Genes and Pheromone Signaling▿

    PubMed Central

    Raudaskoski, Marjatta; Kothe, Erika

    2010-01-01

    The genome sequences of the basidiomycete Agaricomycetes species Coprinopsis cinerea, Laccaria bicolor, Schizophyllum commune, Phanerochaete chrysosporium, and Postia placenta, as well as of Cryptococcus neoformans and Ustilago maydis, are now publicly available. Out of these fungi, C. cinerea, S. commune, and U. maydis, together with the budding yeast Saccharomyces cerevisiae, have been investigated for years genetically and molecularly for signaling in sexual reproduction. The comparison of the structure and organization of mating type genes in fungal genomes reveals an amazing conservation of genes regulating the sexual reproduction throughout the fungal kingdom. In agaricomycetes, two mating type loci, A, coding for homeodomain type transcription factors, and B, encoding a pheromone/receptor system, regulate the four typical mating interactions of tetrapolar species. Evidence for both A and B mating type genes can also be identified in basidiomycetes with bipolar systems, where only two mating interactions are seen. In some of these fungi, the B locus has lost its self/nonself discrimination ability and thus its specificity while retaining the other regulatory functions in development. In silico analyses now also permit the identification of putative components of the pheromone-dependent signaling pathways. Induction of these signaling cascades leads to development of dikaryotic mycelia, fruiting body formation, and meiotic spore production. In pheromone-dependent signaling, the role of heterotrimeric G proteins, components of a mitogen-activated protein kinase (MAPK) cascade, and cyclic AMP-dependent pathways can now be defined. Additionally, the pheromone-dependent signaling through monomeric, small GTPases potentially involved in creating the polarized cytoskeleton for reciprocal nuclear exchange and migration during mating is predicted. PMID:20190072

  7. Molecular epidemiology of clinical and environmental isolates of the Cryptococcus neoformans species complex reveals a high genetic diversity and the presence of the molecular type VGII mating type a in Colombia.

    PubMed

    Escandón, Patricia; Sánchez, Adriana; Martínez, Marcela; Meyer, Wieland; Castañeda, Elizabeth

    2006-06-01

    The aim of this study was to investigate the epidemiological relationships of clinical and environmental isolates of the Cryptococcus neoformans species complex in Colombia. The current study reflects data from 1987 to 2004. In Colombia serotypes A and B are most frequently recovered from patients and the environment. Of the 178 clinical isolates studied, 91.1% were of serotype A, 8.4% serotype B and 0.5% serotype C. Of the 247 environmental isolates, 44.2% were of serotype A, 42.6% serotype B and 13.2% serotype C. No serotype D isolates were isolated. Serotype AD has not been recovered in Colombia. PCR fingerprinting with the primers M13, (GACA)4 and (GTG)5 and URA5 gene restriction fragment length polymorphism analysis grouped the majority of clinical serotype A and environmental serotype B isolates into the molecular types VNI (98.1%) and VGII (100%), respectively. Mating type alpha was determined in 99.3% of serotype A isolates, but 96.6% of serotype B isolates were of mating type a. Similar profiles between clinical and environmental isolates suggest that the patients may have acquired the infection from the environment. The data presented form part of the Colombian contribution to the ongoing global survey of the C. neoformans species complex.

  8. Inversion of the Chromosomal Region between Two Mating Type Loci Switches the Mating Type in Hansenula polymorpha

    PubMed Central

    Maekawa, Hiromi; Kaneko, Yoshinobu

    2014-01-01

    Yeast mating type is determined by the genotype at the mating type locus (MAT). In homothallic (self-fertile) Saccharomycotina such as Saccharomyces cerevisiae and Kluveromyces lactis, high-efficiency switching between a and α mating types enables mating. Two silent mating type cassettes, in addition to an active MAT locus, are essential components of the mating type switching mechanism. In this study, we investigated the structure and functions of mating type genes in H. polymorpha (also designated as Ogataea polymorpha). The H. polymorpha genome was found to harbor two MAT loci, MAT1 and MAT2, that are ∼18 kb apart on the same chromosome. MAT1-encoded α1 specifies α cell identity, whereas none of the mating type genes were required for a identity and mating. MAT1-encoded α2 and MAT2-encoded a1 were, however, essential for meiosis. When present in the location next to SLA2 and SUI1 genes, MAT1 or MAT2 was transcriptionally active, while the other was repressed. An inversion of the MAT intervening region was induced by nutrient limitation, resulting in the swapping of the chromosomal locations of two MAT loci, and hence switching of mating type identity. Inversion-deficient mutants exhibited severe defects only in mating with each other, suggesting that this inversion is the mechanism of mating type switching and homothallism. This chromosomal inversion-based mechanism represents a novel form of mating type switching that requires only two MAT loci. PMID:25412462

  9. Inversion of the chromosomal region between two mating type loci switches the mating type in Hansenula polymorpha.

    PubMed

    Maekawa, Hiromi; Kaneko, Yoshinobu

    2014-11-01

    Yeast mating type is determined by the genotype at the mating type locus (MAT). In homothallic (self-fertile) Saccharomycotina such as Saccharomyces cerevisiae and Kluveromyces lactis, high-efficiency switching between a and α mating types enables mating. Two silent mating type cassettes, in addition to an active MAT locus, are essential components of the mating type switching mechanism. In this study, we investigated the structure and functions of mating type genes in H. polymorpha (also designated as Ogataea polymorpha). The H. polymorpha genome was found to harbor two MAT loci, MAT1 and MAT2, that are ∼18 kb apart on the same chromosome. MAT1-encoded α1 specifies α cell identity, whereas none of the mating type genes were required for a identity and mating. MAT1-encoded α2 and MAT2-encoded a1 were, however, essential for meiosis. When present in the location next to SLA2 and SUI1 genes, MAT1 or MAT2 was transcriptionally active, while the other was repressed. An inversion of the MAT intervening region was induced by nutrient limitation, resulting in the swapping of the chromosomal locations of two MAT loci, and hence switching of mating type identity. Inversion-deficient mutants exhibited severe defects only in mating with each other, suggesting that this inversion is the mechanism of mating type switching and homothallism. This chromosomal inversion-based mechanism represents a novel form of mating type switching that requires only two MAT loci.

  10. Mating types and sexual development in filamentous ascomycetes.

    PubMed Central

    Coppin, E; Debuchy, R; Arnaise, S; Picard, M

    1997-01-01

    The progress made in the molecular characterization of the mating types in several filamentous ascomycetes has allowed us to better understand their role in sexual development and has brought to light interesting biological problems. The mating types of Neurospora crassa, Podospora anserina, and Cochliobolus heterostrophus consist of unrelated and unique sequences containing one or several genes with multiple functions, related to sexuality or not, such as vegetative incompatibility in N. crassa. The presence of putative DNA binding domains in the proteins encoded by the mating-type (mat) genes suggests that they may be transcriptional factors. The mat genes play a role in cell-cell recognition at fertilization, probably by activating the genes responsible for the hormonal signal whose occurrence was previously demonstrated by physiological experiments. They also control recognition between nuclei at a later stage, when reproductive nuclei of each mating type which have divided in the common cytoplasm pair within the ascogenous hyphae. How self is distinguished from nonself at the nuclear level is not known. The finding that homothallic species, able to mate in the absence of a partner, contain both mating types in the same haploid genome has raised more issues than it has resolved. The instability of the mating type, in particular in Sclerotinia trifolorium and Botrytinia fuckeliana, is also unexplained. This diversity of mating systems, still more apparent if the yeasts and the basidiomycetes are taken into account, clearly shows that no single species can serve as a universal mating-type model. PMID:9409146

  11. What uses are mating types? The "developmental switch" model.

    PubMed

    Perrin, Nicolas

    2012-04-01

    Why mating types exist at all is subject to much debate. Among hypotheses, mating types evolved to control organelle transmission during sexual reproduction, or to prevent inbreeding or same-clone mating. Here I review data from a diversity of taxa (including ciliates, algae, slime molds, ascomycetes, and basidiomycetes) to show that the structure and function of mating types run counter the above hypotheses. I argue instead for a key role in triggering developmental switches. Genomes must fulfill a diversity of alternative programs along the sexual cycle. As a haploid gametophyte, an individual may grow vegetatively (through haploid mitoses), or initiate gametogenesis and mating. As a diploid sporophyte, similarly, it may grow vegetatively (through diploid mitoses) or initiate meiosis and sporulation. Only diploid sporophytes (and not haploid gametophytes) should switch on the meiotic program. Similarly, only haploid gametophytes (not sporophytes) should switch on gametogenesis and mating. And they should only do so when other gametophytes are ready to do the same in the neighborhood. As argued here, mating types have evolved primarily to switch on the right program at the right moment.

  12. White-opaque Switching in Different Mating Type-like Locus Gene Types of Clinical Candida albicans Isolates

    PubMed Central

    Li, Hou-Min; Shimizu-Imanishi, Yumi; Tanaka, Reiko; Li, Ruo-Yu; Yaguchi, Takashi

    2016-01-01

    Background: Candida albicans (C. albicans) can become a pathogen causing superficial as well as life-threatening systemic infections, especially in immunocompromised patients. Many phenotypic attributes contribute to its capacity to colonize human organs. In our study, 93 C. albicans isolates from patients of various candidiasis in a hospital of China were surveyed. We aimed to investigate the white-opaque (WO) switching competence, drug sensitivity, and virulence of mating type-like (MTL) a/α isolates. Methods: Internal transcribed spacer (ITS) gene and the MTL configuration were detected in all the isolates by reverse transcription-polymerase chain reaction. White/opaque phenotype and doubling time of cell growth were determined. The minimum inhibitory concentrations of antifungal agent were measured using broth microdilution method. Results: Sixty-four isolates (69.6%) were classified to serotype A, 19 (20.6%) to serotype B, and 9 (9.8%) to serotype C. Moreover, phylogenetic analysis showed that these isolates were divided into four different subgroups of ITS genotypes. Most of our clinical isolates were MTLa/α type, while 6.8% remained MTLa or MTLα type. The frequency of opaque phenotype was 71.0% (66 isolates). Following the guidelines of Clinical and Laboratory Standards Institute M27-A3, all isolates were susceptible to caspofungin and a few (0.6–3.2%) of them showed resistance against amphotericin B, flucytosine, fluconazole, itraconazole, and voriconazole. Conclusions: From these analyses, there were comparatively more C. albicans strains classified into serotype B, and the frequency of opaque phase strains was significant in the clinical isolates from China. Genetic, phenotypic, or drug susceptibility patterns were not significantly different from previous studies. MTLa/α isolates could also undergo WO switching which facilitates their survival. PMID:27824006

  13. Mating-type genes and MAT switching in Saccharomyces cerevisiae.

    PubMed

    Haber, James E

    2012-05-01

    Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break.

  14. The mating type-like loci of Candida glabrata.

    PubMed

    Yáñez-Carrillo, Patricia; Robledo-Márquez, Karina A; Ramírez-Zavaleta, Candy Y; De Las Peñas, Alejandro; Castaño, Irene

    2014-01-01

    Candida glabrata, a haploid and opportunistic fungal pathogen that has not known sexual cycle, has conserved the majority of the genes required for mating and cell type identity. The C. glabrata genome contains three mating-type-like loci called MTL1, MTL2 and MTL3. The three loci encode putative transcription factors, a1, α1 and α2 that regulate cell type identity and sexual reproduction in other fungi like the closely related Saccharomyces cerevisiae. MTL1 can contain either a or α information. MTL2, which contains a information and MTL3 with α information, are relatively close to two telomeres. MTL1 and MTL2 are transcriptionally active, while MTL3 is subject to an incomplete silencing nucleated at the telomere that depends on the silencing proteins Sir2, Sir3, Sir4, yKu70/80, Rif1, Rap1 and Sum1. C. glabrata does not seem to maintain cell type identity, as cell type-specific genes are expressed regardless of the type (or even absence) of mating information. These data highlight important differences in the control of mating and cell type identity between the non-pathogenic yeast S. cerevisiae and C. glabrata, which might explain the absence of a sexual cycle in C. glabrata. The fact that C. glabrata has conserved the vast majority of the genes involved in mating might suggest that some of these genes perhaps have been rewired to control other processes important for the survival inside the host as a commensal or as a human pathogen. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

  15. Sequence diversity of mating-type genes in Phaeosphaeria avenaria.

    PubMed

    Ueng, Peter P; Dai, Qun; Cui, Kai-rong; Czembor, Paweł C; Cunfer, Barry M; Tsang, H; Arseniuk, Edward; Bergstrom, Gary C

    2003-05-01

    Phaeosphaeria avenaria, one of the causal agents of stagonospora leaf blotch diseases in cereals, is composed of two subspecies, P. avenaria f. sp. triticea (Pat) and P. avenaria f. sp. avenaria (Paa). The Pat subspecies was grouped into Pat1-Pat3, based on restriction fragment length polymorphism (RFLP) and ribosomal DNA (rDNA) internal transcribed spacer (ITS) sequences in previous studies. Mating-type genes and their potential use in phylogeny and molecular classification were studied by DNA hybridization and PCR amplification. The majority of Pat1 isolates reported to be homothallic and producing sexual reproduction structures on cultural media had only the MAT1-1 gene. Minor sequence variations were found in the conserved region of MAT1-1 gene in Pat1 isolates. However, both mating-type genes, MAT1-1 and MAT1-2, were identified in P. avenaria isolates represented by ATCC12277 from oats (Paa) and the Pat2 isolates from foxtail barley ( Hordeum jubatum L.). Cluster analyses based on mating-type gene conserved regions revealed that cereal Phaeosphaeria is not phylogenetically closely related to other ascomycetes, including Mycosphaerella graminicola (anamorph Septoria tritici). The sequence diversity of mating-type genes in Pat and Paa supports our previous phylogenetic relationship and molecular classification based on RFLP fingerprinting and rDNA ITS sequences.

  16. Development of a cps-based multiplex PCR for typing of Actinobacillus pleuropneumoniae serotypes 1, 2 and 5.

    PubMed

    Ito, Hiroya

    2010-05-01

    A cps-based multiplex PCR for typing of Actinobacillus pleuropneumoniae serotypes 1, 2 and 5 was developed. This method should be specific and practical in Japan where more than 88% of isolates are serotypes 1, 2 or 5.

  17. Mating-type Gene Switching in Saccharomyces cerevisiae.

    PubMed

    Lee, Cheng-Sheng; Haber, James E

    2015-04-01

    The budding yeast Saccharomyces cerevisiae has two alternative mating types designated MATa and MATα. These are distinguished by about 700 bp of unique sequences, Ya or Yα, including divergent promoter sequences and part of the open reading frames of genes that regulate mating phenotype. Homothallic budding yeast, carrying an active HO endonuclease gene, HO, can switch mating type through a recombination process known as gene conversion, in which a site-specific double-strand break (DSB) created immediately adjacent to the Y region results in replacement of the Y sequences with a copy of the opposite mating type information, which is harbored in one of two heterochromatic donor loci, HMLα or HMRa. HO gene expression is tightly regulated to ensure that only half of the cells in a lineage switch to the opposite MAT allele, thus promoting conjugation and diploid formation. Study of the silencing of these loci has provided a great deal of information about the role of the Sir2 histone deacetylase and its associated Sir3 and Sir4 proteins in creating heterochromatic regions. MAT switching has been examined in great detail to learn about the steps in homologous recombination. MAT switching is remarkably directional, with MATa recombining preferentially with HMLα and MATα using HMRa. Donor preference is controlled by a cis-acting recombination enhancer located near HML. RE is turned off in MATα cells but in MATa binds multiple copies of the Fkh1 transcription factor whose forkhead-associated phosphothreonine binding domain localizes at the DSB, bringing HML into conjunction with MATa.

  18. Gamete signalling underlies the evolution of mating types and their number

    PubMed Central

    Hadjivasiliou, Zena; Pomiankowski, Andrew

    2016-01-01

    The gametes of unicellular eukaryotes are morphologically identical, but are nonetheless divided into distinct mating types. The number of mating types varies enormously and can reach several thousand, yet most species have only two. Why do morphologically identical gametes need to be differentiated into self-incompatible mating types, and why is two the most common number of mating types? In this work, we explore a neglected hypothesis that there is a need for asymmetric signalling interactions between mating partners. Our review shows that isogamous gametes always interact asymmetrically throughout sex and argue that this asymmetry is favoured because it enhances the efficiency of the mating process. We further develop a simple mathematical model that allows us to study the evolution of the number of mating types based on the strength of signalling interactions between gametes. Novel mating types have an advantage as they are compatible with all others and rarely meet their own type. But if existing mating types coevolve to have strong mutual interactions, this restricts the spread of novel types. Similarly, coevolution is likely to drive out less attractive mating types. These countervailing forces specify the number of mating types that are evolutionarily stable. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’. PMID:27619695

  19. Heterothallic Type of Mating System for Cordyceps cardinalis

    PubMed Central

    Sung, Gi-Ho; Shrestha, Bhushan; Han, Sang-Kuk; Kim, Soo-Young

    2010-01-01

    Cordyceps cardinalis successfully produced its fruiting bodies from multi-ascospore isolates. However, subcultures of multi-ascospore isolates could not produce fruiting bodies after few generations. Fruiting body production also differed from sector to sector of the same isolate. Single ascospore isolates were then co-inoculated in combinations of two to observe the fruiting characteristics. Combinations of certain isolates produced perithecial stromata formation, whereas other combinations did not produce any fruiting bodies. These results show that C. cardinalis is a heterothallic fungus, requiring two isolates of opposite mating types for fruiting body production. It was also shown that single ascospore isolates are hermaphrodites. PMID:23956667

  20. Diphthericin types, bacteriophage types and serotypes of Corynebacterium diphtheriae strains isolated in Australia

    PubMed Central

    Gibson, L. F.; Colman, G.

    1973-01-01

    A dipthericin typing scheme has been constructed using 441 strains of Corynebacterium diptheriae isolated in eastern Australia from 1962 to 1971. Ten types have been distinguished using seven strains of C. diphtheriae and two strains of C. belfanti as indicators of the diphthericins produced by the newly isolated strains. Strains grouped into types L2, L3 and L3a were found only in Melbourne and types L1 and L4 were predominant in Sydney. Type L5 strains were isolated intermittently throughout the period of study and were found in all eastern states. Numerical analysis of the characteristics of the strains suggests that associations exist between, on the one hand, diphthericin type and, on the other hand, bacteriophage type, serotype and biochemical activity. PMID:4203597

  1. Erysipelothrix rhusiopathiae: association of Spa-type with serotype and role in protective immunity.

    PubMed

    Ingebritson, Alaina L; Roth, James A; Hauer, Paul J

    2010-03-16

    A collection of swine, fish, and cetacean Erysipelothrix rhusiopathiae strains representing 16 serotypes was analyzed for possession of the three currently recognized surface protective antigen (spa)-types: spaA, spaB, and spaC. Polymerase chain reaction (PCR) assays and Western blotting with a SpaA-specific monoclonal antibody demonstrated that spa-type is not confined to specific serotype groups. In particular, the spa-type of strains of aquatic origin was more variable than those of terrestrial origin, and possessed the distinct ability to express more than one spa. In a cross-protection study, mice immunized with an E. rhusiopathiae serotype 2 SpaA-type strain and challenged with various E. rhusiopathiae isolates were completely protected against strains exhibiting a single homologous spa, but variably protected against strains possessing a heterologous spa or those harboring more than one spa-type.

  2. Biotyping, serotyping and phage typing of Streptococcus faecalis isolated from dental plaque in the human mouth.

    PubMed

    Smyth, C J; Matthews, H; Halpenny, M K; Brandis, H; Colman, G

    1987-02-01

    Thirty Streptococcus faecalis isolates from mixed dental plaque samples were classified into four groups on the basis of biotype, tetracycline susceptibility, phage type and serotype combinations. The organisms were from patients on haemodialysis, from staff of the dialysis unit, and from controls. Three biotypes were distinguished by seven biochemical tests: production of acid from inositol, sucrose and xylose; rapid or delayed production of acid from sorbitol; gelatin liquefaction; and production of alkaline phosphatase and beta-galactosidase. With a set of eight typing antisera for S. faecalis, 15 strains were non-typable, 12 were serotype 1 and three were serotype 19. With a set of 17 bacteriophages specific for S. faecalis, all of the oral isolates were typable; 40% were lysotype I1 and the remainder lysotype V6b. On the basis of biotype-serotype-phage-type combinations, indications of possible spread of strains between haemodialysis patients and dialysis unit staff were obtained. Biotyping and serotyping of 13 German isolates of S. faecalis of phage type I1 from four clinical sources and tripartite typing of three control strains provided additional evidence for the potential of biotyping in distinguishing between strains of identical serotype and phage type. One oral isolate of S. faecium was of phage type XX. None of the oral isolates of S. faecalis, of which 14 exhibited delayed sorbitol fermentation, reacted with group-G streptococcal grouping reagents or antiserum. Slow sorbitol fermentation does not appear to be a definitive phenotypic marker for S. faecalis strains possessing antigens that react with both group-D and group-G grouping reagents.

  3. Genotype and mating type distribution within clinical Cryptococcus neoformans and Cryptococcus gattii isolates from patients with cryptococcal meningitis in Uberaba, Minas Gerais, Brazil.

    PubMed

    Mora, Delio José; Pedrosa, André Luiz; Rodrigues, Virmondes; Leite Maffei, Claudia Maria; Trilles, Luciana; Dos Santos Lazéra, Márcia; Silva-Vergara, Mario León

    2010-06-01

    We molecularly characterized 81 cryptococcal isolates recovered from cerebrospinal fluid samples of 77 patients diagnosed between 1998 and 2007 as having cryptococcal meningitis in Uberaba Minas Gerais, Brazil. Fifty-seven (74%) were male with a mean age 35.6 years. Seventy-two (88.9%) of the isolates were from 68 AIDS patients and cryp-tococcosis was the first AIDS-defining condition in 38 (55.9%) patients. Cryptococcosis and AIDS were simultaneously diagnosed in 25 (65.8%) of these 38 patients. Genotypes were characterized through the use of URA5 restriction fragment length polymorphisms analysis, the genetic variability was determined using PCR-fingerprinting with the minisatellite-specific primer M13, and the mating type and serotypes were established by PCR. Seventy-six of the 81 isolates were Cryptococcus neoformans (93.8%), while the remaining five were C. gattii (6.1%), but all were mating type alpha. C. neoformans isolates were genotype VNI (serotype A), while C. gattii isolates were VGII. Four of the latter isolates were identical, but only two were from AIDS patients. Six of the nine isolates from non-AIDS patients were VNI. PCR fingerprints of the isolates from two of the three AIDS patients with clinical relapse were 100% identical. The predominance of VNI and mating type alpha is in accordance with data from other parts of the world. The occurrence of VGII in Minas Gerais indicates a geographical expansion within Brazil.

  4. Serotype IV Sequence Type 468 Group B Streptococcus Neonatal Invasive Disease, Minnesota, USA

    PubMed Central

    Teatero, Sarah; Ferrieri, Patricia

    2016-01-01

    To further understand the emergence of serotype IV group B Streptococcus (GBS) invasive disease, we used whole-genome sequencing to characterize 3 sequence type 468 strains isolated from neonates in Minnesota, USA. We found that strains of tetracycline-resistant sequence type 468 GBS have acquired virulence genes from a putative clonal complex 17 GBS donor by recombination. PMID:27767922

  5. Molecular typing of Cryptococcus neoformans by PCR fingerprinting, in comparison with serotyping and Fourier transform infrared-spectroscopy-based phenotyping.

    PubMed

    Lemmer, K; Naumann, D; Raddatz, B; Tintelnot, K

    2004-04-01

    Molecular typing by PCR fingerprinting using the single primer (GACA)4 was performed with 110 isolates of Cryptococcus neoformans. Seventy clinical isolates of C. neoformans var. neoformans from Germany (n = 52) and Africa (n = 18) were included. Of these, serotype A (C. neoformans var. grubii) accounted for 47 isolates, serotype D for 12 and serotype AD for 11. Fourier transform infrared (FT-IR) spectroscopy was evaluated for its discriminatory power in phenotyping. Molecular types, defined by different PCR fingerprinting patterns, were compared to serotypes, and both sets of results were compared with the results of analysis by FT-IR spectroscopy. PCR fingerprinting revealed genotypic diversity within each serotype; it showed three different genotypes (designated VNA1-VNA3) within serotype A, two within serotype D (VND1 and VND2), and three within serotype AD (VNAD1-VNAD3). The nomenclature of molecular types within C. n. var. neoformans, as seen in publications to date, is not uniform. In this study, the name assigned to each genotype was based on the 98.6% concordance of genotypes with serotypes, a correspondence that facilitates interlaboratory comparison. This nomenclature is tentatively recommended as a standard. FT-IR spectroscopy combined with hierarchical cluster analysis successfully distinguished C n. var. neoformans from C. n. var. gattii. For C. n. var. neoformans, FT-IR confirmed three distinct genotypes within serotype A and was able to distinguish isolates derived from particular patients as well as isolates differing at the sub-genotype level. Within C. n. var. gattii, the serotypes B and C did not correlate with the four genotypes VGI-VGIV. However, these serotypes could clearly be separated by FT-IR spectroscopy. The molecular profiles were reproducible, and were more stable and more discriminating than serotyping. In connection with a standardized nomenclature, PCR fingerprinting can be a beneficial tool for global epidemiological studies. FT

  6. Mating success of wild type and sepia mutants Drosophila melanogaster in different choice.

    PubMed

    Stanić, Snezana; Pavković-Lucic, Sofija

    2005-01-01

    Mating behaviour of red-eyed (wt) and brown-eyed (sepia) Drosophila melanogaster was studied under light conditions. Mating success was directly observed in mating vials and techniques usually applied in the studies of sexual selection ("female choice" and "multiple choice"). The comparison of sexual activity of mutant and wild types clearly indicates that they are not equally successful in matings. Sepia eye colour mutation decreases sexual activity of Drosophila melanogaster males, influences the preference ability of females and decreases the number of progeny from homogamic mating of the se x se type, as well as from heterogamic copulations in which sepia females take part. Non-random mating of wild type males and sepia females (in "multiple-choice" situation), with genetically and phenotypically different individuals, could be another mechanism for conservation of genetic polymorphism in natural populations.

  7. Clonality and serotypes of Streptococcus mutans among children by multilocus sequence typing

    PubMed Central

    Momeni, Stephanie S.; Whiddon, Jennifer; Cheon, Kyounga; Moser, Stephen A.; Childers, Noel K.

    2015-01-01

    Studies using multilocus sequence typing (MLST) have demonstrated that Streptococcus mutans isolates are genetically diverse. Our laboratory previously demonstrated clonality of S. mutans using MLST but could not discount the possibility of sampling bias. In this study, the clonality of randomly selected S. mutans plaque isolates from African American children was examined using MLST. Serotype and presence of collagen-binding proteins (CBP) cnm/cbm were also assessed. One hundred S. mutans isolates were randomly selected for MLST analysis. Sequence analysis was performed and phylogenetic trees were generated using START2 and MEGA. Thirty-four sequence types (ST) were identified of which 27 were unique to this population. Seventy-five percent of the isolates clustered into 16 clonal groups. Serotypes observed were c (n=84), e (n=3), and k (n=11). The prevalence of S. mutans isolates serotype k was notably high at 17.5%. All isolates were cnm/cbm negative. The clonality of S. mutans demonstrated in this study illustrates the importance of localized populations studies and are consistent with transmission. The prevalence of serotype k, a recently proposed systemic pathogen, observed in this study is higher than reported in most populations and is the first report of S. mutans serotype k in a US population. PMID:26443288

  8. Population Structure and Antimicrobial Resistance Profiles of Streptococcus suis Serotype 2 Sequence Type 25 Strains

    PubMed Central

    Athey, Taryn B. T.; Teatero, Sarah; Takamatsu, Daisuke; Wasserscheid, Jessica; Dewar, Ken; Gottschalk, Marcelo; Fittipaldi, Nahuel

    2016-01-01

    Strains of serotype 2 Streptococcus suis are responsible for swine and human infections. Different serotype 2 genetic backgrounds have been defined using multilocus sequence typing (MLST). However, little is known about the genetic diversity within each MLST sequence type (ST). Here, we used whole-genome sequencing to test the hypothesis that S. suis serotype 2 strains of the ST25 lineage are genetically heterogeneous. We evaluated 51 serotype 2 ST25 S. suis strains isolated from diseased pigs and humans in Canada, the United States of America, and Thailand. Whole-genome sequencing revealed numerous large-scale rearrangements in the ST25 genome, compared to the genomes of ST1 and ST28 S. suis strains, which result, among other changes, in disruption of a pilus island locus. We report that recombination and lateral gene transfer contribute to ST25 genetic diversity. Phylogenetic analysis identified two main and distinct Thai and North American clades grouping most strains investigated. These clades also possessed distinct patterns of antimicrobial resistance genes, which correlated with acquisition of different integrative and conjugative elements (ICEs). Some of these ICEs were found to be integrated at a recombination hot spot, previously identified as the site of integration of the 89K pathogenicity island in serotype 2 ST7 S. suis strains. Our results highlight the limitations of MLST for phylogenetic analysis of S. suis, and the importance of lateral gene transfer and recombination as drivers of diversity in this swine pathogen and zoonotic agent. PMID:26954687

  9. Genetic and Physical Variability at the Mating Type Locus of the Oomycete, Phytophthora Infestans

    PubMed Central

    Judelson, H. S.

    1996-01-01

    Mating type in the oomyceteous fungus, Phytophthora infestans, is determined by a single locus. In a previous study of a few isolates, the locus segregated in a manner genetically consistent with its linkage to a system of balanced lethal loci. To determine the prevalence of this phenomenon within P. infestans, genetic analyses were performed using isolates representative of the diversity within the species that had been selected by DNA fingerprinting using probes linked to mating type. Non-Mendelian segregation of the mating type locus was observed in crosses performed with each isolate. An unusual group of isolates was identified in which the mating type determinants had been rearranged within the genome; these strains also produced an aberrantly large number of self-fertile progeny. Curiously, in all isolates, markers linked to the mating type locus appeared prone to duplication, transposition, deletion, or other rearrangement. This was not observed for loci unlinked to mating type. Data from the crosses and analyses of marker variation were used to erect models to explain the bases of mating type determination and of the unusual segregation of the chromosomal region containing the mating type locus. PMID:8913745

  10. Group B Streptococcus Serotype III Sequence Type 283 Bacteremia Associated with Consumption of Raw Fish, Singapore

    PubMed Central

    Lin, Yijun; Foo, Kelly; Koh, Han Fang; Tow, Charlene; Zhang, Yiwen; Ang, Li Wei; Cui, Lin; Badaruddin, Hishamuddin; Ooi, Peng Lim; Lin, Raymond Tzer Pin; Cutter, Jeffery

    2016-01-01

    We conducted a retrospective study of 40 case-patients and 58 controls as part of a nationwide investigation of a group B Streptococcus outbreak in Singapore in 2015. Eating a Chinese-style raw fish dish (yusheng) was a major risk factor for bacteremia, particularly caused by serotype III sequence type 283. PMID:27767904

  11. Hypervirulent Clone of Group B Streptococcus Serotype III Sequence Type 283, Hong Kong, 1993–2012

    PubMed Central

    Ang, Irene; Fung, Kitty; Liyanapathirana, Veranja; Luo, Ming Jing; Lai, Raymond

    2016-01-01

    We describe a hypervirulent clone of group B Streptococcus serotype III, subtype 4, sequence type 283, that caused invasive disease with a predilection for meningitis in Hong Kong during 1993–2012. The organism is associated with high mortality and increased summer prevalence and is linked to diseased fish from freshwater fish farms. PMID:27648702

  12. Serotyping of Toxoplasma gondii in Cats (Felis domesticus) Reveals Predominance of Type II Infections in Germany

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Cats are definitive hosts of Toxoplasma gondii and play an essential role in the epidemiology of this parasite. The study aims at clarifying whether cats are able to develop specific antibodies against different clonal types of T. gondii and to determine by serotyping the T. gondii clona...

  13. Genetic Instability in the Mating Type System of Tetrahymena pigmentosa

    PubMed Central

    Simon, Ellen M.; Orias, Eduardo

    1987-01-01

    Selfing clones of Tetrahymena pigmentosa show several interesting genetic features, and provide some insight into the mechanisms of mating type (mt) determination. They differ significantly from those of Tetrahymena thermophila. They are distributed nonrandomly in crosses. Their rates of stabilization are highly variable, but most are much lower than those reported for T. thermophila. A number of subclones derived from nearly all the selfers have maintained stable mts in culture for several years. However, some subclones manifest persistent selfing, long after the calculated completion of allelic assortment for heterozygous loci. This phenomenon along with the perpetual maintenance of dominant mts in heterozygotes shows that phenotypic assortment is not involved in mt expression.—In crosses, many selfers exhibit quantitative and qualitative aberrations in the transmission of alleles to the gametes; some of the micronuclear changes underlying these aberrations occur during vegetative growth. There are rare illegitimate appearances of dominant alleles in sexual progeny, and more common illegitimate appearances of the most recessive phenotype.—Various models to explain mt determination in this species are considered. One which might account for the troubling phenomena of the system consists of an active mat expression site, with "cassettes" at other sites specific for the different dominant alleles and capable of transposition to the expression site. PMID:3692137

  14. Evolution of Mating Systems in Basidiomycetes and the Genetic Architecture Underlying Mating-Type Determination in the Yeast Leucosporidium scottii

    PubMed Central

    Maia, Teresa M.; Lopes, Susana T.; Almeida, João M. G. C. F.; Rosa, Luiz H.; Sampaio, José Paulo; Gonçalves, Paula; Coelho, Marco A.

    2015-01-01

    In most fungi, sexual reproduction is bipolar; that is, two alternate sets of genes at a single mating-type (MAT) locus determine two mating types. However, in the Basidiomycota, a unique (tetrapolar) reproductive system emerged in which sexual identity is governed by two unlinked MAT loci, each of which controls independent mechanisms of self/nonself recognition. Tetrapolar-to-bipolar transitions have occurred on multiple occasions in the Basidiomycota, resulting, for example, from linkage of the two MAT loci into a single inheritable unit. Nevertheless, owing to the scarcity of molecular data regarding tetrapolar systems in the earliest-branching lineage of the Basidiomycota (subphylum Pucciniomycotina), it is presently unclear if the last common ancestor was tetrapolar or bipolar. Here, we address this question, by investigating the mating system of the Pucciniomycotina yeast Leucosporidium scottii. Using whole-genome sequencing and chromoblot analysis, we discovered that sexual reproduction is governed by two physically unlinked gene clusters: a multiallelic homeodomain (HD) locus and a pheromone/receptor (P/R) locus that is biallelic, thereby dismissing the existence of a third P/R allele as proposed earlier. Allele distribution of both MAT genes in natural populations showed that the two loci were in strong linkage disequilibrium, but independent assortment of MAT alleles was observed in the meiotic progeny of a test cross. The sexual cycle produces fertile progeny with similar proportions of the four mating types, but approximately 2/3 of the progeny was found to be nonhaploid. Our study adds to others in reinforcing tetrapolarity as the ancestral state of all basidiomycetes. PMID:26178967

  15. Dynamics of mitochondrial inheritance in the evolution of binary mating types and two sexes.

    PubMed

    Hadjivasiliou, Zena; Lane, Nick; Seymour, Robert M; Pomiankowski, Andrew

    2013-10-22

    The uniparental inheritance (UPI) of mitochondria is thought to explain the evolution of two mating types or even true sexes with anisogametes. However, the exact role of UPI is not clearly understood. Here, we develop a new model, which considers the spread of UPI mutants within a biparental inheritance (BPI) population. Our model explicitly considers mitochondrial mutation and selection in parallel with the spread of UPI mutants and self-incompatible mating types. In line with earlier work, we find that UPI improves fitness under mitochondrial mutation accumulation, selfish conflict and mitonuclear coadaptation. However, we find that as UPI increases in the population its relative fitness advantage diminishes in a frequency-dependent manner. The fitness benefits of UPI 'leak' into the biparentally reproducing part of the population through successive matings, limiting the spread of UPI. Critically, while this process favours some degree of UPI, it neither leads to the establishment of linked mating types nor the collapse of multiple mating types to two. Only when two mating types exist beforehand can associated UPI mutants spread to fixation under the pressure of high mitochondrial mutation rate, large mitochondrial population size and selfish mutants. Variation in these parameters could account for the range of UPI actually observed in nature, from strict UPI in some Chlamydomonas species to BPI in yeast. We conclude that UPI of mitochondria alone is unlikely to have driven the evolution of two mating types in unicellular eukaryotes.

  16. Evolution of sexes from an ancestral mating-type specification pathway.

    PubMed

    Geng, Sa; De Hoff, Peter; Umen, James G

    2014-07-01

    Male and female sexes have evolved repeatedly in eukaryotes but the origins of dimorphic sexes and their relationship to mating types in unicellular species are not understood. Volvocine algae include isogamous species such as Chlamydomonas reinhardtii, with two equal-sized mating types, and oogamous multicellular species such as Volvox carteri with sperm-producing males and egg-producing females. Theoretical work predicts genetic linkage of a gamete cell-size regulatory gene(s) to an ancestral mating-type locus as a possible step in the evolution of dimorphic gametes, but this idea has not been tested. Here we show that, contrary to predictions, a single conserved mating locus (MT) gene in volvocine algae-MID, which encodes a RWP-RK domain transcription factor-evolved from its ancestral role in C. reinhardtii as a mating-type specifier, to become a determinant of sperm and egg development in V. carteri. Transgenic female V. carteri expressing male MID produced functional sperm packets during sexual development. Transgenic male V. carteri with RNA interference (RNAi)-mediated knockdowns of VcMID produced functional eggs, or self-fertile hermaphrodites. Post-transcriptional controls were found to regulate cell-type-limited expression and nuclear localization of VcMid protein that restricted its activity to nuclei of developing male germ cells and sperm. Crosses with sex-reversed strains uncoupled sex determination from sex chromosome identity and revealed gender-specific roles for male and female mating locus genes in sexual development, gamete fitness and reproductive success. Our data show genetic continuity between the mating-type specification and sex determination pathways of volvocine algae, and reveal evidence for gender-specific adaptations in the male and female mating locus haplotypes of Volvox. These findings will enable a deeper understanding of how a master regulator of mating-type determination in an ancestral unicellular species was reprogrammed to

  17. Erysipelothrix spp. genotypes, serotypes, and surface protective antigen types associated with abattoir condemnations.

    PubMed

    Bender, Joseph S; Irwin, Christa K; Shen, Hui-Gang; Schwartz, Kent J; Opriessnig, Tanja

    2011-01-01

    The objective of the current study was to investigate characteristics of Erysipelothrix spp. from slaughter condemnations. Specimens from 70 carcasses with lesions suspect for swine erysipelas were collected at an abattoir in Iowa from October 2007 to February 2009. Erysipelothrix spp. were isolated from 59 of 70 carcasses (84.3%). Abattoir inspectors classified lesions as acute, subacute, or chronic; 8 of 8 (100%) were acute cases, 31 of 32 (96.9%) were subacute cases, and 20 of 30 (66.6%) were chronic cases that were isolation positive. The following serotypes were identified: 1a (40.7%; 24/59), 2 (49.2%; 29/59), 7 (1/59), 10 (1/59), 11 (1/59), and untypeable (5.1%; 3/59). Serotypes 1a and 2 were identified in pigs with acute, subacute, or chronic clinical manifestations, whereas serotypes 7, 10, and 11 were only present in chronic cases. Fifty-seven of the 59 isolates were determined to belong to E. rhusiopathiae, and 2 of 59 of the isolates were determined to be E. tonsillarum by multiplex real-time polymerase chain reaction. Surface protective antigen (spa) A was detected in all E. rhusiopathiae isolates but not in E. tonsillarum serotypes 7 and 10. The results of the present study indicate that E. rhusiopathiae serotypes 1a and 2 continue to be commonly isolated from condemned pig carcasses and that spaA is the exclusive spa type in U.S. abattoir isolates. Interestingly, E. tonsillarum, thought to be avirulent for swine, was isolated from systemic sites from 3.4% of the carcasses that were negative for E. rhusiopathiae, indicating the potential importance of this genotype in erysipelas pathogenesis.

  18. Pseudohomothallism and evolution of the mating-type chromosome in Neurospora tetrasperma

    SciTech Connect

    Merino, S.T.; Nelson, M.A.; Natvig, D.O.

    1996-06-01

    Ascospores of Neurospora tetrasperma normally contain nuclei of both mating-type idiomorphs (a and A), resulting in self-fertile heterokaryons (a type of sexual reproduction termed pseudohomothallism). Occasional homokaryotic self-sterile strains (either a or A) behave as heterothallics and, in principal, provide N. tetrasperma to assess levels of intrastrain heterokaryosis (heterozygosity). The unexpected result was the mating-type chromosome and autosomes exhibited very different patterns of evolution, apparently because of suppressed recombination between mating-type chromosomes. Analysis of sequences on the mating-type chromosomes of wild-collected self-fertile strains revealed high levels of genetic variability between sibling A and a nuclei. In contrast, sequences on autosomes of sibling A and a nuclei exhibited nearly complete homogeneity. Conservation of distinct haplotype combinations on A and a mating-type chromosomes in strains from diverse locations further suggested an absence of recombination over substantial periods of evolutionary time. The suppression of recombination of the N. tetrasperma mating-type chromosome, expected to ensure a high frequency of self fertility, presents an interesting parallel with, and possible model for studying aspects of, the evolution of mammalian sex chromosomes. 39 refs., 5 figs., 1 tab.

  19. Multiple Clones within Multidrug-Resistant Salmonella enterica Serotype Typhimurium Phage Type DT104

    PubMed Central

    Markogiannakis, Antonis; Tassios, Panayotis T.; Lambiri, Maria; Ward, Linda R.; Kourea-Kremastinou, Jenny; Legakis, Nicholas J.; Vatopoulos, Alkiviadis C.

    2000-01-01

    Six distinct clones were present among Greek multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104, since isolates belonging to resistance phenotypes including the ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) core could be distinguished with respect to their pulsed-field gel electrophoresis patterns, int1 integron structures, and presence or absence of antibiotic resistance genes ant(3")-Ia, pse-1, and tem-1. PMID:10699039

  20. Differentiation between Atypical Isolates of Candida lusitaniae and Candida pulcherrima by Determination of Mating Type

    PubMed Central

    Noël, Thierry; Favel, Anne; Michel-Nguyen, Annie; Goumar, Abdelhak; Fallague, Karim; Chastin, Christiane; Leclerc, Florence; Villard, Jean

    2005-01-01

    We report on five clinical isolates routinely identified as Candida lusitaniae that the ID 32C system was unable to discriminate from the closely related species Candida pulcherrima. When additional tests did not allow accurate identification, the less usual mating type test identified all of them as Clavispora lusitaniae. Mating type testing appears to be a valuable tool for assessing the true incidence of this emerging non-albicans Candida species. PMID:15750124

  1. Mutations Affecting Donor Preference during Mating Type Interconversion in Saccharomyces Cerevisiae

    PubMed Central

    Weiler, K. S.; Szeto, L.; Broach, J. R.

    1995-01-01

    Homothallic strains of Saccharomyces cerevisiae can convert mating type from a to α or α to a as often as every generation, by replacing genetic information specifying one mating type at the expressor locus, MAT, with information specifying the opposite mating type. The cryptic mating type information that is copied and inserted at MAT is contained in either of two loci, HML or HMR. The particular locus selected as donor during mating type interconversion is regulated by the allele expressed at MAT. MATa cells usually select HML, and MATα cells usually select HMR, a process referred to as donor preference. To identify factors required for donor preference, we isolated and characterized a number of mutants that frequently selected the nonpreferred donor locus during mating type interconversion. Many of these mutants were found to harbor chromosome rearrangements or mutations at MAT or HML that interfered with the switching process. However, one mutant carried a recessive allele of CHL1, a gene previously shown to be required for efficient chromosome segregation during mitosis. Homothallic strains of yeast containing a null allele of CHL1 exhibited almost random selection of the donor locus in a MATa background but were normal in their ability to select HMR in a MATα background. Our results indicate that Chl1p participates in the process of donor selection and are consistent with a model in which Chl1p helps establish an intrinsic bias in donor preference. PMID:7789755

  2. Sex in smut fungi: Structure, function and evolution of mating-type complexes.

    PubMed

    Bakkeren, Guus; Kämper, Jörg; Schirawski, Jan

    2008-08-01

    Smut fungi are basidiomycete plant pathogens that pose a threat to many important cereal crops. In order to be pathogenic on plants, smut fungal cells of compatible mating-type need to fuse. Fusion and pathogenicity are regulated by two loci, a and b, which harbor conserved genes. The functions of the encoded mating-type complexes have been well-studied in the model fungus Ustilago maydis and will be briefly reviewed here. Sequence comparison of the mating-type loci of different smut and related fungi has revealed that these loci differ substantially in structure. These structural differences point to an evolution from tetrapolar to bipolar mating behavior, which might have occurred several independent times during fungal speciation.

  3. Analysis of Molecular Epidemiology of Chilean Salmonella enterica Serotype Enteritidis Isolates by Pulsed-Field Gel Electrophoresis and Bacteriophage Typing

    PubMed Central

    Fernandez, Jorge; Fica, Alberto; Ebensperger, German; Calfullan, Hector; Prat, Soledad; Fernandez, Alda; Alexandre, Marcela; Heitmann, Ingrid

    2003-01-01

    Human Salmonella enterica serotype Enteritidis infections emerged in Chile in 1994. S. enterica serotype Enteritidis phage type 1 isolates predominated in the north, and phage type 4 isolates predominated in the central and southern regions. A study was planned to characterize this epidemic using the best discriminatory typing technique. Research involved 441 S. enterica serotype Enteritidis isolates, including clinical preepidemic samples (n = 74; 1975 to 1993) and epidemic (n = 199), food (n = 72), poultry (n = 57), and some Latin American (n = 39) isolates. The best method was selected based on a sample of preepidemic isolates, analyzing the discriminatory power (DP) obtained by phage typing and randomly amplified polymorphic DNA and pulsed-field gel electophoresis (PFGE) analysis. The highest DP was associated with BlnI PFGE-bacteriophage typing analysis (0.993). A total of 38 BlnI patterns (B patterns) were identified before the epidemic period, 19 since 1994, and only 4 in both periods. Two major clusters were identified by phylogenetic analysis, and the predominant B patterns clustered in the same branch. Combined analysis revealed that specific B pattern-phage type combinations (subtypes) disappeared before 1994, that different genotypes associated with S. enterica serotype Enteritidis phage type 4 had been observed since 1988, and that strain diversity increased before the expansion of S. enterica serotype Enteritidis in 1994. Predominant subtype B3-phage type 4 was associated with the central and southern regions, and subtype B38-phage type 1 was associated with the north (P < 0.0001). Food and poultry isolates matched the predominant S. enterica serotype Enteritidis subtypes, but isolates identified in neighboring countries (Peru and Bolivia) did not match S. enterica serotype Enteritidis subtypes identified in the north of Chile. The results of this work demonstrate that genetic diversity, replacement, and expansion of specific S. enterica serotype

  4. Occurrence and Distribution of Mating Types of Pseudoperonospora cubensis in the United States.

    PubMed

    Thomas, Anna; Carbone, Ignazio; Cohen, Yigal; Ojiambo, Peter S

    2017-03-01

    During the past two decades, a resurgence of cucurbit downy mildew has occurred around the world, resulting in severe disease epidemics. In the United States, resurgence of the disease occurred in 2004 and several hypotheses, including introduction of a new genetic recombinant or pathotype of the pathogen, have been suggested as potential causes for this resurgence. Occurrence and distribution of mating types of Pseudoperonospora cubensis in the United States were investigated using 40 isolates collected from cucurbits across 11 states from 2005 to 2013. Pairing of unknown isolates with known mating-type tester strains on detached leaves of cantaloupe or cucumber resulted in oospore formation 8 to 10 days after inoculation. Isolates differed in their ability to form oospores across all coinoculation pairings, with oospore numbers ranging from 280 to 1,000 oospores/cm(2) of leaf tissue. Oospores were hyaline to golden-yellow, spherical, and approximately 36 μm in diameter. Of the 40 isolates tested, 24 were found to be of the A1 mating type, while 16 were of the A2 mating type. Mating type was significantly (P < 0.0001) associated with host type, whereby all isolates collected from cucumber were of the A1 mating type, while isolates from squash and watermelon were of the A2 mating type. Similarly, mating type was significantly (P = 0.0287) associated with geographical region, where isolates from northern-tier states of Michigan, New Jersey, New York, and Ohio were all A1, while isolates belonging to either A1 or A2 mating type were present in equal proportions in southern-tier states of Alabama, Florida, Georgia, North Carolina, South Carolina, and Texas. Viability assays showed that oospores were viable and, on average, approximately 40% of the oospores produced were viable as determined by the plasmolysis method. This study showed that A1 and A2 mating types of P. cubensis are present and the pathogen could potentially reproduce sexually in cucurbits within the

  5. Cell-cell signalling in sexual chemotaxis: a basis for gametic differentiation, mating types and sexes.

    PubMed

    Hadjivasiliou, Zena; Iwasa, Yoh; Pomiankowski, Andrew

    2015-08-06

    While sex requires two parents, there is no obvious need for them to be differentiated into distinct mating types or sexes. Yet this is the predominate state of nature. Here, we argue that mating types could play a decisive role because they prevent the apparent inevitability of self-stimulation during sexual signalling. We rigorously assess this hypothesis by developing a model for signaller-detector dynamics based on chemical diffusion, chemotaxis and cell movement. Our model examines the conditions under which chemotaxis improves partner finding. Varying parameter values within ranges typical of protists and their environments, we show that simultaneous secretion and detection of a single chemoattractant can cause a multifold movement impediment and severely hinder mate finding. Mutually exclusive roles result in faster pair formation, even when cells conferring the same roles cannot pair up. This arrangement also allows the separate mating types to optimize their signalling or detecting roles, which is effectively impossible for cells that are both secretors and detectors. Our findings suggest that asymmetric roles in sexual chemotaxis (and possibly other forms of sexual signalling) are crucial, even without morphological differences, and may underlie the evolution of gametic differentiation among both mating types and sexes.

  6. Cell–cell signalling in sexual chemotaxis: a basis for gametic differentiation, mating types and sexes

    PubMed Central

    Hadjivasiliou, Zena; Iwasa, Yoh; Pomiankowski, Andrew

    2015-01-01

    While sex requires two parents, there is no obvious need for them to be differentiated into distinct mating types or sexes. Yet this is the predominate state of nature. Here, we argue that mating types could play a decisive role because they prevent the apparent inevitability of self-stimulation during sexual signalling. We rigorously assess this hypothesis by developing a model for signaller–detector dynamics based on chemical diffusion, chemotaxis and cell movement. Our model examines the conditions under which chemotaxis improves partner finding. Varying parameter values within ranges typical of protists and their environments, we show that simultaneous secretion and detection of a single chemoattractant can cause a multifold movement impediment and severely hinder mate finding. Mutually exclusive roles result in faster pair formation, even when cells conferring the same roles cannot pair up. This arrangement also allows the separate mating types to optimize their signalling or detecting roles, which is effectively impossible for cells that are both secretors and detectors. Our findings suggest that asymmetric roles in sexual chemotaxis (and possibly other forms of sexual signalling) are crucial, even without morphological differences, and may underlie the evolution of gametic differentiation among both mating types and sexes. PMID:26156301

  7. Antibodies Directed against Shiga-Toxin Producing Escherichia coli Serotype O103 Type III Secreted Proteins Block Adherence of Heterologous STEC Serotypes to HEp-2 Cells

    PubMed Central

    Desin, Taseen S.; Townsend, Hugh G.; Potter, Andrew A.

    2015-01-01

    Shiga toxin-producing Escherichia coli (STEC) serotype O103 is a zoonotic pathogen that is capable of causing hemorrhagic colitis and hemolytic uremic syndrome (HUS) in humans. The main animal reservoir for STEC is ruminants and hence reducing the levels of this pathogen in cattle could ultimately lower the risk of STEC infection in humans. During the process of infection, STECO103 uses a Type III Secretion System (T3SS) to secrete effector proteins (T3SPs) that result in the formation of attaching and effacing (A/E) lesions. Vaccination of cattle with STEC serotype O157 T3SPs has previously been shown to be effective in reducing shedding of STECO157 in a serotype-specific manner. In this study, we tested the ability of rabbit polyclonal sera against individual STECO103 T3SPs to block adherence of the organism to HEp-2 cells. Our results demonstrate that pooled sera against EspA, EspB, EspF, NleA and Tir significantly lowered the adherence of STECO103 relative to pre-immune sera. Likewise, pooled anti-STECO103 sera were also able to block adherence by STECO157. Vaccination of mice with STECO103 recombinant proteins induced strong IgG antibody responses against EspA, EspB, NleA and Tir but not against EspF. However, the vaccine did not affect fecal shedding of STECO103 compared to the PBS vaccinated group over the duration of the experiment. Cross reactivity studies using sera against STECO103 recombinant proteins revealed a high degree of cross reactivity with STECO26 and STECO111 proteins implying that sera against STECO103 proteins could potentially provide neutralization of attachment to epithelial cells by heterologous STEC serotypes. PMID:26451946

  8. Alpha mating type-specific expression of mutations leading to constitutive agglutinability in Saccharomyces cerevisiae.

    PubMed Central

    Doi, S; Yoshimura, M

    1985-01-01

    Two mutants of Saccharomyces cerevisiae have been isolated and characterized. The mutants were constitutively agglutinable at 36 degrees C, the temperature at which wild-type cells agglutinate only after induction by mating pheromone. The mutant cells had other properties specific for the normal alpha cell type, i.e., conjugation with a cells, response to a mating pheromone, and production of alpha mating pheromone. The two mutations, cag1 and cag2, were recessive and expressed only in alpha cells. cag1 is linked very closely to the MAT locus, but cag2 is unlinked to the MAT locus. These cag mutations complemented ste3-1. These results indicate that CAG genes are novel alpha-specific genes involved in the regulation of sex agglutinin synthesis. PMID:3881403

  9. Crystal Structure of Botulinum Neurotoxin Type G Light Chain - Serotype Divergence in Substrate Recognition†,‡

    PubMed Central

    Arndt, Joseph W.; Yu, Wayne; Bi, Fay; Stevens, Raymond C.

    2008-01-01

    The seven serotypes (A–G) of botulinum neurotoxins (BoNTs) block neurotransmitter release through their specific proteolysis of one of the three proteins of the soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) complex. BoNTs have stringent substrate specificities that are unique for metalloprotease in that they require exceptionally long substrates (1). In order to understand the molecular reasons for the unique specificities of the BoNTs, we determined the crystal structure of the catalytic light chain (LC) of Clostridium botulinum neurotoxin type G (BoNT/G-LC) at 2.35 Å resolution. The structure of BoNT/G-LC reveals a C-terminal β-sheet that is critical for LC oligomerization and is unlike that seen in the other LC structures. Its structural comparison with thermolysin and the available pool of LC structures reveals important serotype differences that are likely to be involved in substrate recognition of the P1’ residue. In addition, structural and sequence analysis have identified a potential exosite of BoNT/G-LC that recognizes a SNARE recognition motif of VAMP. PMID:16008342

  10. Crystal structure of botulinum neurotoxin type G light chain: serotype divergence in substrate recognition.

    PubMed

    Arndt, Joseph W; Yu, Wayne; Bi, Fay; Stevens, Raymond C

    2005-07-19

    The seven serotypes (A-G) of botulinum neurotoxins (BoNTs) block neurotransmitter release through their specific proteolysis of one of the three proteins of the soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) complex. BoNTs have stringent substrate specificities that are unique for metalloprotease in that they require exceptionally long substrates (1). To understand the molecular reasons for the unique specificities of the BoNTs, we determined the crystal structure of the catalytic light chain (LC) of Clostridium botulinum neurotoxin type G (BoNT/G-LC) at 2.35 A resolution. The structure of BoNT/G-LC reveals a C-terminal beta-sheet that is critical for LC oligomerization and is unlike that seen in the other LC structures. Its structural comparison with thermolysin and the available pool of LC structures reveals important serotype differences that are likely to be involved in substrate recognition of the P1' residue. In addition, structural and sequence analyses have identified a potential exosite of BoNT/G-LC that recognizes a SNARE recognition motif of VAMP.

  11. RAS/Cyclic AMP and Transcription Factor Msn2 Regulate Mating and Mating-Type Switching in the Yeast Kluyveromyces lactis ▿

    PubMed Central

    Barsoum, E.; Rajaei, N.; Åström, S. U.

    2011-01-01

    In response to harsh environmental conditions, ascomycetes produce stress-resistant spores to promote survival. As sporulation requires a diploid DNA content, species with a haploid lifestyle, such as Kluyveromyces lactis, first induce mating in response to stress. In K. lactis, mating and mating-type switching are induced by the DNA-binding protein Mts1. Mts1 expression is known to be upregulated by nutrient limitation, but the mechanism is unknown. We show that a ras2 mutation results in a hyperswitching phenotype. In contrast, strains lacking the phosphodiesterase Pde2 had lower switching rates compared to that of the wild type (WT). As Ras2 promotes cyclic AMP (cAMP) production and Pde2 degrades cAMP, these data suggest that low cAMP levels induce switching. Because the MTS1 regulatory region contains several Msn2 binding sites and Msn2 is a transcription factor that is activated by low cAMP levels, we investigated if Msn2 regulates MTS1 transcription. Consistently with this idea, an msn2 mutant strain displayed lower switching rates than the WT strain. The transcription of MTS1 is highly induced in the ras2 mutant strain. In contrast, an msn2 ras2 double mutant strain displays WT levels of the MTS1 transcript, showing that Msn2 is a critical inducer of MTS1 transcription. Strains lacking Msn2 and Pde2 also exhibit mating defects that can be complemented by the ectopic expression of Mts1. Finally, we show that MTS1 is subjected to negative autoregulation, presumably adding robustness to the mating and switching responses. We suggest a model in which Ras2/cAMP/Msn2 mediates the stress-induced mating and mating-type switching responses in K. lactis. PMID:21890818

  12. Population structure and mating type distribution of the chickpea blight pathogen Ascochyta rabiei from Pakistan and United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ascochyta blight caused by the fungus Ascochyta rabiei (AR) depresses chickpea production in Pakistan and worldwide. Thirty two AR isolates representing six geographical regions of Pakistan was compared with a US AR population for frequency of mating types and genetic variation. Mating type results ...

  13. Advances in Understanding Mating Type Gene Organization in the Mushroom-Forming Fungus Flammulina velutipes

    PubMed Central

    Wang, Wei; Lian, Lingdan; Xu, Ping; Chou, Tiansheng; Mukhtar, Irum; Osakina, Aron; Waqas, Muhammad; Chen, Bingzhi; Liu, Xinrui; Liu, Fang; Xie, Baogui; van Peer, Arend F.

    2016-01-01

    The initiation of sexual development in the important edible and medicinal mushroom Flammulina velutipes is controlled by special genes at two different, independent, mating type (MAT) loci: HD and PR. We expanded our understanding of the F. velutipes mating type system by analyzing the MAT loci from a series of strains. The HD locus of F. velutipes houses homeodomain genes (Hd genes) on two separated locations: sublocus HD-a and HD-b. The HD-b subloci contained strain-specific Hd1/Hd2 gene pairs, and crosses between strains with different HD-b subloci indicated a role in mating. The function of the HD-a sublocus remained undecided. Many, but not all strains contained the same conserved Hd2 gene at the HD-a sublocus. The HD locus usually segregated as a whole, though we did detect one new HD locus with a HD-a sublocus from one parental strain, and a HD-b sublocus from the other. The PR locus of F. velutipes contained pheromone receptor (STE3) and pheromone precursor (Pp) genes at two locations, sublocus PR-a and PR-b. PR-a and PR-b both contained sets of strain-specific STE3 and Pp genes, indicating a role in mating. PR-a and PR-b cosegregated in our experiments. However, the identification of additional strains with identical PR-a, yet different PR-b subloci, demonstrated that PR subloci can recombine within the PR locus. In conclusion, at least three of the four MAT subloci seem to participate in mating, and new HD and PR loci can be generated through intralocus recombination in F. velutipes. PMID:27621376

  14. Relationship between Monokaryotic Growth Rate and Mating Type in the Edible Basidiomycete Pleurotus ostreatus

    PubMed Central

    Larraya, Luis M.; Pérez, Gúmer; Iribarren, Iñaki; Blanco, Juan A.; Alfonso, Mikel; Pisabarro, Antonio G.; Ramírez, Lucía

    2001-01-01

    The edible fungus Pleurotus ostreatus (oyster mushroom) is an industrially produced heterothallic homobasidiomycete whose mating is controlled by a bifactorial tetrapolar genetic system. Two mating loci (matA and matB) control different steps of hyphal fusion, nuclear migration, and nuclear sorting during the onset and progress of the dikaryotic growth. Previous studies have shown that the segregation of the alleles present at the matB locus differs from that expected for a single locus because (i) new nonparental B alleles appeared in the progeny and (ii) there was a distortion in the segregation of the genomic regions close to this mating locus. In this study, we pursued these observations by using a genetic approach based on the identification of molecular markers linked to the matB locus that allowed us to dissect it into two genetically linked subunits (matBα and matBβ) and to correlate the presence of specific matBα and matA alleles with differences in monokaryotic growth rate. The availability of these molecular markers and the mating type dependence of growth rate in monokaryons can be helpful for marker-assisted selection of fast-growing monokaryons to be used in the construction of dikaryons able to colonize the substrate faster than the competitors responsible for reductions in the industrial yield of this fungus. PMID:11472908

  15. Serotyping of primary human immunodeficiency virus type 1 isolates from diverse geographic locations by flow cytometry.

    PubMed Central

    Zolla-Pazner, S; O'Leary, J; Burda, S; Gorny, M K; Kim, M; Mascola, J; McCutchan, F

    1995-01-01

    The immunologic relatedness of the various human immunodeficiency virus type 1 (HIV-1) clades was determined with 13 human anti-HIV-1 monoclonal antibodies (MAbs) to six immunogenic regions of the HIV-1 structural proteins. The immunoreactivity of the native, oligomeric viral envelope glycoproteins expressed on the surfaces of human peripheral blood mononuclear cells infected in vitro with primary isolates from clades A through E was determined by flow cytometry. Some epitopes in the immunodominant region of gp41 and the C terminus of gp120 appear to be HIV-1 group specific in that they are expressed on the surfaces of cells in cultures infected with the majority of viruses tested from clades A to E. Epitopes within the V3 region appear to be clade restricted. Surprisingly, one MAb to an epitope in the C terminus of gp120 was entirely clade B specific. Staining with anti-V2 and anti-CD4 binding domain (CD4bd) reagents was infrequently detected. Anti-CD4bd MAbs stained only CD4-negative T cells because the CD4bd of gp120 appeared to be complexed with membrane CD4. When present, the epitopes of V2 and the CD4bd appeared to be expressed on cells infected with various clades. Thus, the results suggest that MAbs to gp41, the C terminus, and the V3 loop of gp120 are most useful in serotyping primary isolates of HIV-1, providing group-specific, clade-restricted, and clade-specific reagents. The use of the immunofluorescent method with the reagents described herein distinguishes infection with clade B from that with all other HIV-1 clades. With additional MAbs, this technique will allow a broadly applicable, reproducible, and practical method for serotyping HIV-1. PMID:7745728

  16. Genome-defence small RNAs exapted for epigenetic mating-type inheritance.

    PubMed

    Singh, Deepankar Pratap; Saudemont, Baptiste; Guglielmi, Gérard; Arnaiz, Olivier; Goût, Jean-François; Prajer, Malgorzata; Potekhin, Alexey; Przybòs, Ewa; Aubusson-Fleury, Anne; Bhullar, Simran; Bouhouche, Khaled; Lhuillier-Akakpo, Maoussi; Tanty, Véronique; Blugeon, Corinne; Alberti, Adriana; Labadie, Karine; Aury, Jean-Marc; Sperling, Linda; Duharcourt, Sandra; Meyer, Eric

    2014-05-22

    In the ciliate Paramecium, transposable elements and their single-copy remnants are deleted during the development of somatic macronuclei from germline micronuclei, at each sexual generation. Deletions are targeted by scnRNAs, small RNAs produced from the germ line during meiosis that first scan the maternal macronuclear genome to identify missing sequences, and then allow the zygotic macronucleus to reproduce the same deletions. Here we show that this process accounts for the maternal inheritance of mating types in Paramecium tetraurelia, a long-standing problem in epigenetics. Mating type E depends on expression of the transmembrane protein mtA, and the default type O is determined during development by scnRNA-dependent excision of the mtA promoter. In the sibling species Paramecium septaurelia, mating type O is determined by coding-sequence deletions in a different gene, mtB, which is specifically required for mtA expression. These independently evolved mechanisms suggest frequent exaptation of the scnRNA pathway to regulate cellular genes and mediate transgenerational epigenetic inheritance of essential phenotypic polymorphisms.

  17. HIV type 1 V3 serotyping of Tanzanian samples: probable reasons for mismatching with genetic subtyping.

    PubMed

    Hoelscher, M; Hanker, S; Barin, F; Cheingsong-Popov, R; Dietrich, U; Jordan-Harder, B; Olaleye, D; Nägele, E; Markuzzi, A; Mwakagile, D; Minja, F; Weber, J; Gürtler, L; Von Sonnenburg, F

    1998-01-20

    HIV-1 V3 serotyping is used to classify immunodeficiency viruses on the basis of antibody binding to V3 peptides derived from env genetic subtypes. Although it shows a reasonable overlap, it has been reported to be distinct from viral genetic subtypes. The aim of this study is to determine the feasibility of HIV-1 serotyping to predict genetic subtypes in an East African setting, where multiple HIV-1 subtypes have coexisted for many years. HIV-1 genetic subtypes of 86 AIDS patients in Mbeya Town, southwest Tanzania, were determined, using env nucleic acid sequencing as the basis for comparison. Those data were compared with V3 serotyping results obtained by four different methodologies. Four HIV-1 genetic subtypes were identified, including A (25, 29%), C (47, 55%), D (13, 15%), and G (1, 1%). The sensitivity and specificity of those serotyping assays varied considerably: sensitivity for genetic subtype A (40-48%), C (52-96%), and D (9-31%); and specificity for genetic subtype A (77-95%), C (46-63%), and D (97-100%). We further tried to identify reasons for the discrepancies between serotyping results and genetic subtypes. By means of logistic regression analysis three amino acid residues within the V3 loop (positions 12, 13, and 19; V, H, and A for serotype A, I, R, and T for serotype C) were found to be most important for antibody binding; a deviation from the subtype-specific amino acids was highly related to mismatched results. In addition, we have shown that phenetic analysis of V3 amino acid sequence data could be used to predict the majority of V3 serotypes (93-94%). Our data demonstrated that for the majority of specimens HIV-1 V3 serotyping results closely match the subtype of the analyzed sample as revealed by the V3 loop amino acid sequence. However, our data demonstrate that HIV-1 serotyping is not sufficiently accurate to predict genetic subtypes in Tanzania, where subtypes A, C, D, and G are circulating. This was due to highly similar amino acid

  18. Transcription of two long noncoding RNAs mediates mating-type control of gametogenesis in budding yeast.

    PubMed

    van Werven, Folkert J; Neuert, Gregor; Hendrick, Natalie; Lardenois, Aurélie; Buratowski, Stephen; van Oudenaarden, Alexander; Primig, Michael; Amon, Angelika

    2012-09-14

    The cell-fate decision leading to gametogenesis is essential for sexual reproduction. In S. cerevisiae, only diploid MATa/α but not haploid MATa or MATα cells undergo gametogenesis, known as sporulation. We find that transcription of two long noncoding RNAs (lncRNAs) mediates mating-type control of sporulation. In MATa or MATα haploids, expression of IME1, the central inducer of gametogenesis, is inhibited in cis by transcription of the lncRNA IRT1, located in the IME1 promoter. IRT1 transcription recruits the Set2 histone methyltransferase and the Set3 histone deacetylase complex to establish repressive chromatin at the IME1 promoter. Inhibiting expression of IRT1 and an antisense transcript that antagonizes the expression of the meiotic regulator IME4 allows cells expressing the haploid mating type to sporulate with kinetics that are indistinguishable from that of MATa/α diploids. Conversely, expression of the two lncRNAs abolishes sporulation in MATa/α diploids. Thus, transcription of two lncRNAs governs mating-type control of gametogenesis in yeast.

  19. Asexual cephalosporin C producer Acremonium chrysogenum carries a functional mating type locus.

    PubMed

    Pöggeler, Stefanie; Hoff, Birgit; Kück, Ulrich

    2008-10-01

    Acremonium chrysogenum, the fungal producer of the pharmaceutically relevant beta-lactam antibiotic cephalosporin C, is classified as asexual because no direct observation of mating or meiosis has yet been reported. To assess the potential of A. chrysogenum for sexual reproduction, we screened an expressed sequence tag library from A. chrysogenum for the expression of mating type (MAT) genes, which are the key regulators of sexual reproduction. We identified two putative mating type genes that are homologues of the alpha-box domain gene, MAT1-1-1 and MAT1-1-2, encoding an HPG domain protein defined by the presence of the three invariant amino acids histidine, proline, and glycine. In addition, cDNAs encoding a putative pheromone receptor and pheromone-processing enzymes, as well as components of a pheromone response pathway, were found. Moreover, the entire A. chrysogenum MAT1-1 (AcMAT1-1) gene and regions flanking the MAT region were obtained from a genomic cosmid library, and sequence analysis revealed that in addition to AcMAT1-1-1 and AcMAT1-1-2, the AcMAT1-1 locus comprises a third mating type gene, AcMAT1-1-3, encoding a high-mobility-group domain protein. The alpha-box domain sequence of AcMAT1-1-1 was used to determine the phylogenetic relationships of A. chrysogenum to other ascomycetes. To determine the functionality of the AcMAT1-1 locus, the entire MAT locus was transferred into a MAT deletion strain of the heterothallic ascomycete Podospora anserina (the PaDeltaMAT strain). After fertilization with a P. anserina MAT1-2 (MAT(+)) strain, the corresponding transformants developed fruiting bodies with mature ascospores. Thus, the results of our functional analysis of the AcMAT1-1 locus provide strong evidence to hypothesize a sexual cycle in A. chrysogenum.

  20. Functional convergence and divergence of mating-type genes fulfilling in Cordyceps militaris.

    PubMed

    Lu, Yuzhen; Xia, Yongliang; Luo, Feifei; Dong, Caihong; Wang, Chengshu

    2016-03-01

    Fungal sexual lives are considerably diversified in terms of the types of mating systems and mating-control gene functions. Sexual fruiting bodies of the ascomycete fungus Cordyceps militaris have been widely consumed as edible and medicinal mushrooms, whereas the regulation of fruiting-body development and sex in this fungus remain elusive. Herein, we performed the comprehensive functional analyses of mating-type (MAT) genes in C. militaris. Interspecies functional convergence was evident that MAT1-1 and MAT1-2-1 null mutants were sterile and lost the ability to produce stromata in outcrosses with the opposite mating-type partner. In contrast to other fungal species, functional divergence of MAT1-1-1 and MAT1-1-2 was also observed that ΔMAT1-1-1 produced barren stromata in outcrosses, whereas ΔMAT1-1-2 generated fruiting bodies morphologically similar to that of the parental strain but with sterile perithecia. The homothallic-like transformants MAT1-2::MAT1-1-1 (haploidic MAT1-2 isolate transformed with the MAT1-1-1 gene) produced sterile stromata, whereas the MAT1-1::MAT1-2-1 (haploidic MAT1-1 isolate transformed with the MAT1-2-1 gene) mutant was determined to be completely fruitless. The findings relating to the fully fertile gene-complementation mutants suggest that the genomic location is not essential for the MAT genes to fulfill their functions in C. militaris. Comparison of the production of bioactive constituents cordycepin and adenosine provides experimental support that the fungal sexual cycle is an energy consuming process. The results of the present study enrich our knowledge of both convergent and divergent controls of fungal sex.

  1. Whole Genome Sequencing of 39 Invasive Streptococcus pneumoniae Sequence Type 199 Isolates Revealed Switches from Serotype 19A to 15B

    PubMed Central

    Lucas, Marie; Brandt, Christian; Herrmann, Leonie; Albersmeier, Andreas; Blom, Jochen; Goesmann, Alexander

    2017-01-01

    Streptococcus pneumoniae is a major pathogen that causes different invasive pneumococcal diseases (IPD). The pneumococcal polysaccharide capsule is a main virulence factor. More than 94 capsule types have been described, but only a limited number of capsule types accounted for the majority of IPD cases before the introduction of pneumococcal vaccines. After the introduction of the conjugated pneumococcal vaccine PCV7, which covered the seven most frequent serotypes in IPD in the USA, an increase in IPD caused by non-vaccine serotypes was observed, and serotype 19A, which belongs to sequence type (ST) 199, was among the most prevalent STs. After the introduction of the extended vaccine PCV13, which includes serotype 19A, serogroup 15B/C increased in IPD. Therefore, whole genome sequences of 39 isolates of ST199 from Germany (collected between 1998 and 2011) with serotype 19A (n = 24) and serogroup 15B/C (n = 15) were obtained using an Illumina platform and were analysed to identify capsular switches within ST199. Two 19A to 15B/C serotype switch events were identified. Both events occurred before the introduction of PCV7, which indicates that a capsular switch from 19A to 15B among ST199 isolates is not unusual and is not directly linked to the vaccination. The observed serotype replacement appears to be the result of a vacant niche due to the displacement of vaccine serotypes that is now successfully occupied by ST199 clones. PMID:28046133

  2. Whole Genome Sequencing of 39 Invasive Streptococcus pneumoniae Sequence Type 199 Isolates Revealed Switches from Serotype 19A to 15B.

    PubMed

    Makarewicz, Oliwia; Lucas, Marie; Brandt, Christian; Herrmann, Leonie; Albersmeier, Andreas; Rückert, Christian; Blom, Jochen; Goesmann, Alexander; van der Linden, Mark; Kalinowski, Jörn; Pletz, Mathias W

    2017-01-01

    Streptococcus pneumoniae is a major pathogen that causes different invasive pneumococcal diseases (IPD). The pneumococcal polysaccharide capsule is a main virulence factor. More than 94 capsule types have been described, but only a limited number of capsule types accounted for the majority of IPD cases before the introduction of pneumococcal vaccines. After the introduction of the conjugated pneumococcal vaccine PCV7, which covered the seven most frequent serotypes in IPD in the USA, an increase in IPD caused by non-vaccine serotypes was observed, and serotype 19A, which belongs to sequence type (ST) 199, was among the most prevalent STs. After the introduction of the extended vaccine PCV13, which includes serotype 19A, serogroup 15B/C increased in IPD. Therefore, whole genome sequences of 39 isolates of ST199 from Germany (collected between 1998 and 2011) with serotype 19A (n = 24) and serogroup 15B/C (n = 15) were obtained using an Illumina platform and were analysed to identify capsular switches within ST199. Two 19A to 15B/C serotype switch events were identified. Both events occurred before the introduction of PCV7, which indicates that a capsular switch from 19A to 15B among ST199 isolates is not unusual and is not directly linked to the vaccination. The observed serotype replacement appears to be the result of a vacant niche due to the displacement of vaccine serotypes that is now successfully occupied by ST199 clones.

  3. Mating type loci of Sporisorium reilianum: novel pattern with three a and multiple b specificities.

    PubMed

    Schirawski, Jan; Heinze, Bernadette; Wagenknecht, Martin; Kahmann, Regine

    2005-08-01

    Sporisorium reilianum and Ustilago maydis are two closely related smut fungi, which both infect maize but differ fundamentally in their mode of plant invasion and site of symptom development. As a prelude to studying the molecular basis of these differences, we have characterized the mating type loci of S. reilianum. S. reilianum has two unlinked mating type loci, a and b. Genes in both loci and adjacent regions show a high degree of synteny to the corresponding genes of U. maydis. The b locus occurs in at least five alleles and encodes two subunits of a heterodimeric homeodomain transcription factor, while the a locus encodes a pheromone/receptor system. However, in contrast to that of U. maydis, the a locus of S. reilianum exists in three alleles containing two active pheromone genes each. The alleles of the a locus appear to have arisen through recent recombination events within the locus itself. This has created a situation where each pheromone is specific for recognition by only one mating partner.

  4. Mating Type Loci of Sporisorium reilianum: Novel Pattern with Three a and Multiple b Specificities

    PubMed Central

    Schirawski, Jan; Heinze, Bernadette; Wagenknecht, Martin; Kahmann, Regine

    2005-01-01

    Sporisorium reilianum and Ustilago maydis are two closely related smut fungi, which both infect maize but differ fundamentally in their mode of plant invasion and site of symptom development. As a prelude to studying the molecular basis of these differences, we have characterized the mating type loci of S. reilianum. S. reilianum has two unlinked mating type loci, a and b. Genes in both loci and adjacent regions show a high degree of synteny to the corresponding genes of U. maydis. The b locus occurs in at least five alleles and encodes two subunits of a heterodimeric homeodomain transcription factor, while the a locus encodes a pheromone/receptor system. However, in contrast to that of U. maydis, the a locus of S. reilianum exists in three alleles containing two active pheromone genes each. The alleles of the a locus appear to have arisen through recent recombination events within the locus itself. This has created a situation where each pheromone is specific for recognition by only one mating partner. PMID:16087737

  5. Comparison of proteome typing and serotyping of Streptococcus parauberis isolates from olive flounder (Paralichthys olivaceus).

    PubMed

    Kim, Si Won; Jang, Ho Bin; Lee, Jung Seok; Im, Se Pyeong; Lazarte, Jassy Mary S; Seo, Jong Pyo; Lee, Woo Jai; Kim, Jae Sung; Jung, Tae Sung

    2015-11-01

    The olive flounder (Paralichthys olivaceus) is a cultivated marine species that is economically important in Korea and Japan. Several bacterial pathogens have caused severe mortalities in farmed olive flounder, especially Streptococcus parauberis. We collected 145 S. parauberis isolates from diseased olive flounders from 2003 to 2008 in Jeju Island, South Korea and characterized them by Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI TOF MS) and by serology. The serological analysis divided the isolates into serotype I (62.1%) and serotype II (36.6%) and the proteome analysis divided the isolates into cluster 1 (43.4%) and cluster 2 (56.6%). All cluster 1 isolates had serotype I, but cluster 2 consisted of serotype I (32.9%), serotype II (64.6%), and others (2.5%). Further detailed analysis of the mass spectra led to identification of several specific m/z peaks that enabled discrimination between cluster 1 and 2 and between serotype I and II within cluster 2. Our results suggest that MALDI TOF MS analysis has potential as an alternative method for the rapid and reliable identification of the fish pathogen S. parauberis.

  6. Altered Mating-Type Identity in the Fungus Podospora Anserina Leads to Selfish Nuclei, Uniparental Progeny, and Haploid Meiosis

    PubMed Central

    Zickler, D.; Arnaise, S.; Coppin, E.; Debuchy, R.; Picard, M.

    1995-01-01

    In wild-type crosses of the filamentous ascomycete Podospora anserina, after fertilization, only nuclei of opposite mating type can form dikaryons that undergo karyogamy and meiosis, producing biparental progeny. To determine the role played by the mating type in these steps, the four mat genes were mutagenized in vitro and introduced into a strain deleted for its mat locus. Genetic and cytological analyses of these mutant strains, crossed to each other and to wild type, showed that mating-type information is required for recognition of nuclear identity during the early steps of sexual reproduction. In crosses with strains carrying a mating-type mutation, two unusual developmental patterns were observed: monokaryotic cells, resulting in haploid meiosis, and uniparental dikaryotic cells providing, after karyogamy and meiosis, a uniparental progeny. Altered mating-type identity leads to selfish behavior of the mutant nucleus: it migrates alone or paired, ignoring its wild-type partner in all mutant X wild-type crosses. This behavior is nucleus-autonomous because, in the same cytoplasm, the wild-type nuclei form only biparental dikaryons. In P. anserina, mat genes are thus required to ensure a biparental dikaryotic state but appear dispensable for later stages, such as meiosis and sporulation. PMID:7498731

  7. Chromosome-refolding model of mating-type switching in yeast.

    PubMed

    Avşaroğlu, Barış; Bronk, Gabriel; Li, Kevin; Haber, James E; Kondev, Jane

    2016-10-24

    Chromosomes are folded into cells in a nonrandom fashion, with particular genetic loci occupying distinct spatial regions. This observation raises the question of whether the spatial organization of a chromosome governs its functions, such as recombination or transcription. We consider this general question in the specific context of mating-type switching in budding yeast, which is a model system for homologous recombination. Mating-type switching is induced by a DNA double-strand break (DSB) at the MAT locus on chromosome III, followed by homologous recombination between the cut MAT locus and one of two donor loci (HMLα and HMRa), located on the same chromosome. Previous studies have suggested that in MATa cells after the DSB is induced chromosome III undergoes refolding, which directs the MAT locus to recombine with HMLα. Here, we propose a quantitative model of mating-type switching predicated on the assumption of DSB-induced chromosome refolding, which also takes into account the previously measured stochastic dynamics and polymer nature of yeast chromosomes. Using quantitative fluorescence microscopy, we measure changes in the distance between the donor (HMLα) and MAT loci after the DSB and find agreement with the theory. Predictions of the theory also agree with measurements of changes in the use of HMLα as the donor, when we perturb the refolding of chromosome III. These results establish refolding of yeast chromosome III as a key driving force in MAT switching and provide an example of a cell regulating the spatial organization of its chromosome so as to direct homology search during recombination.

  8. Mating-type orthologous genes in the primarily homothallic Moniliophthora perniciosa, the causal agent of Witches' Broom Disease in cacao.

    PubMed

    Kües, Ursula; Navarro-González, Mónica

    2010-10-01

    The cacao-pathogenic Moniliophthora perniciosa C-biotype is a primarily homothallic Agaricomycete of which the genome has recently become available. Searching of the genome sequence with mating type proteins from other basidiomycetes detected one or possibly two potential genes for HD1 homeodomain transcription factors, 7 or possibly 8 genes for potential pheromone receptors and five genes for putative pheromone precursors. Apparently, the fungus possesses gene functions encoded in the tetrapolar basidiomycetes in the A and B mating loci, respectively. In the tetrapolar species, the A and B mating type genes govern formation of clamp cells at hyphal septa of the dikaryon and their fusion with sub-apical cells as well as mushroom production. The C-biotype forms fused clamp cells and also basidiocarps on mycelia germinated from basidiospores and their development might be controlled by the detected genes. It represents the first example of a primarily homothallic basidiomycete where A - and B -mating-type-like genes were found. Various strategies are discussed as how self-compatibility in presence of such genes can evolve. An A -mating-type like gene for an HD2 homeodomain transcription factor is, however, not included in the available sequence representing estimated 69% coverage of the haploid genome but there are non-mating genes for other homeodomain transcription factors of currently unknown function that are conserved in basidiomycetes and also various ascomycetes.

  9. Chromosomal Rearrangements in Salmonella enterica Serotype Typhi Affecting Molecular Typing in Outbreak Investigations

    PubMed Central

    Echeita, M. A.; Usera, M. A.

    1998-01-01

    Salmonella enterica serotype Typhi strains belonging to eight different outbreaks of typhoid fever that occurred in Spain between 1989 and 1994 were analyzed by ribotyping and pulsed-field gel electrophoresis. For three outbreaks, two different patterns were detected for each outbreak. The partial digestion analysis by the intron-encoded endonuclease I-CeuI of the two different strains from each outbreak provided an excellent tool for examining the organization of the genomes of epidemiologically related strains. S. enterica serotype Typhi seems to be more susceptible than other serotypes to genetic rearrangements produced by homologous recombinations between rrn operons; these rearrangements do not substantially alter the stability or survival of the bacterium. We conclude that genetic rearrangements can occur during the emergence of an outbreak. PMID:9650981

  10. Genome-Wide Gene Expression Profiling of Fertilization Competent Mycelium in Opposite Mating Types in the Heterothallic Fungus Podospora anserina

    PubMed Central

    Coppin, Evelyne; Imbeaud, Sandrine; Grognet, Pierre; Delacroix, Hervé; Debuchy, Robert

    2011-01-01

    Background Mating-type loci in yeasts and ascomycotan filamentous fungi (Pezizomycotina) encode master transcriptional factors that play a critical role in sexual development. Genome-wide analyses of mating-type-specification circuits and mating-type target genes are available in Saccharomyces cerevisiae and Schizosaccharomyces pombe; however, no such analyses have been performed in heterothallic (self-incompatible) Pezizomycotina. The heterothallic fungus Podospora anserina serves as a model for understanding the basic features of mating-type control. Its mat+ and mat− mating types are determined by dissimilar allelic sequences. The mat− sequence contains three genes, designated FMR1, SMR1 and SMR2, while the mat+ sequence contains one gene, FPR1. FMR1 and FPR1 are the major regulators of fertilization, and this study presents a genome-wide view of their target genes and analyzes their target gene regulation. Methodology/Principal Findings The transcriptomic profiles of the mat+ and mat− strains revealed 157 differentially transcribed genes, and transcriptomic analysis of fmr1− and fpr1− mutant strains was used to determine the regulatory actions exerted by FMR1 and FPR1 on these differentially transcribed genes. All possible combinations of transcription repression and/or activation by FMR1 and/or FPR1 were observed. Furthermore, 10 additional mating-type target genes were identified that were up- or down-regulated to the same level in mat+ and mat− strains. Of the 167 genes identified, 32 genes were selected for deletion, which resulted in the identification of two genes essential for the sexual cycle. Interspecies comparisons of mating-type target genes revealed significant numbers of orthologous pairs, although transcriptional profiles were not conserved between species. Conclusions/Significance This study represents the first comprehensive genome-wide analysis of mating-type direct and indirect target genes in a heterothallic filamentous fungus

  11. Transcription of the mating-type-regulated lncRNA IRT1 is governed by TORC1 and PKA.

    PubMed

    Moretto, Fabien; van Werven, Folkert J

    2016-08-12

    Cell fate decisions are controlled by multiple cell-intrinsic and -extrinsic factors. In budding yeast, the decision to enter gametogenesis or sporulation is dictated by nutrient availability and mating type. Recently, we showed that in diploid cells harbouring opposite mating types (MATa and MATα), the protein kinase A (PKA) and target of rapamycin complex I (TORC1) signalling pathways integrate at the promoter of the master regulatory transcription factor IME1 to control sporulation via nutrient availability (Weidberg, et al. 2016). In cells with a single mating type (MATa or MATα), however, IME1 is repressed by transcription through the IME1 promoter of a long non-coding RNA called IRT1, which prevents this cell type from undergoing sporulation. Here, we investigated the role of nutrient signalling in mating-type control of IME1. We find that expression of IRT1, like IME1 itself, depends on nutrient availability and the activities of PKA and TORC1. IRT1 transcription is repressed when nutrients are ample and TORC1 and PKA are active. In contrast, inhibition of PKA and TORC1 is sufficient to recruit Rme1 to the IRT1 promoter and induce IRT1-mediated repression of IME1. Finally, we provide evidence that IRT1 and IME1 are co-repressed by the Tup1-Cyc8 complex when nutrients are ample. Thus, in cells with a single mating-type nutrient availability regulates mating-type repression of IME1 and sporulation. Our results indicate that there is a hierarchy between nutrient and mating-type signals in controlling the decision to enter sporulation.

  12. Virulence Studies of Different Sequence Types and Geographical Origins of Streptococcus suis Serotype 2 in a Mouse Model of Infection

    PubMed Central

    Auger, Jean-Philippe; Fittipaldi, Nahuel; Benoit-Biancamano, Marie-Odile; Segura, Mariela; Gottschalk, Marcelo

    2016-01-01

    Multilocus sequence typing previously identified three predominant sequence types (STs) of Streptococcus suis serotype 2: ST1 strains predominate in Eurasia while North American (NA) strains are generally ST25 and ST28. However, ST25/ST28 and ST1 strains have also been isolated in Asia and NA, respectively. Using a well-standardized mouse model of infection, the virulence of strains belonging to different STs and different geographical origins was evaluated. Results demonstrated that although a certain tendency may be observed, S. suis serotype 2 virulence is difficult to predict based on ST and geographical origin alone; strains belonging to the same ST presented important differences of virulence and did not always correlate with origin. The only exception appears to be NA ST28 strains, which were generally less virulent in both systemic and central nervous system (CNS) infection models. Persistent and high levels of bacteremia accompanied by elevated CNS inflammation are required to cause meningitis. Although widely used, in vitro tests such as phagocytosis and killing assays require further standardization in order to be used as predictive tests for evaluating virulence of strains. The use of strains other than archetypal strains has increased our knowledge and understanding of the S. suis serotype 2 population dynamics. PMID:27409640

  13. Recovery of Saccharomyces cerevisiae mating-type a cells from G1 arrest by alpha factor.

    PubMed Central

    Chan, R K

    1977-01-01

    Mating-type a cells of the yeast Saccharomyces cerevisiae that had been specifically arrested in the G1 phase of the cell cycle by alpha factor, an oligopeptide pheromone made by alpha cells, recovered and resumed cell division after a period of inhibition which was dependent on the concentration of alpha factor used. These treated a cells were more resistant to alpha factor than untreated a cells, but lost their resistance upon further cell division. However, cells arrested for 6 h were no more resistant to alpha factor than cells arrested for only 2.5 h. Mating-type a strains could inactivate or remove alpha factor from the culture fluid, but two a sterile (nonmating) mutants and an a/alpha diploid strain could not. These results suggest that a cells have a mechanism, which may involve uptake or inactivation of alpha factor, for recovering from alpha factor arrest. However, the results do not distinguish between a recovery mechanism which is constitutive and one which is induced by alpha factor. The loss of alpha factor activity during recovery appeared to be primarily cell contact mediated, although an extracellular, diffusible inhibitor of alpha factor that is labile or that functions stoichiometrically could not be ruled out. PMID:400792

  14. Capsular Polysaccharide (CPS) Release by Serotype 3 Pneumococcal Strains Reduces the Protective Effect of Anti-Type 3 CPS Antibodies.

    PubMed

    Choi, Eun Hwa; Zhang, Fan; Lu, Ying-Jie; Malley, Richard

    2015-12-16

    The efficacy of the serotype 3 (ST3) pneumococcal conjugate vaccine (PCV) remains unclear. While the synthesis of capsular polysaccharide (CPS) of most serotypes is wzy dependent, the strains of two serotypes, 3 and 37, synthesize CPS by the synthase-dependent pathway, resulting in a polysaccharide that is not covalently linked to peptidoglycan and can be released during growth. We hypothesized that the release of CPS during growth reduces anti-type 3 CPS antibody-mediated protection and may explain the lower efficacy of the type 3 component of PCV than that of other PCVs. The in vitro-released CPS concentrations per 10(7) CFU of ST3 and ST37 strains were significantly higher than those for the ST1, ST4, ST6B, and ST14 strains. Following intraperitoneal (i.p.) injection in mice, blood concentrations of CPS were significantly higher for the ST3 than for the ST4/5 strains. The opsonophagocytic killing assay (OPKA) titer of anti-type 3 CPS antibody was significantly reduced by type 3 CPS, culture supernatant, or serum from Streptococcus pneumoniae ST3 strain WU2-infected mice. Mice were injected with capsule-specific antibodies and challenged i.p. with or without the addition of sterile culture supernatant containing type-specific CPS. The addition of 0.2 μl of culture supernatant from WU2 inhibited passive protection, whereas 100-fold-more culture supernatant from S. pneumoniae ST4 strain TIGR4 was required for the inhibition of protection. We conclude that released type 3 CPS interferes with antibody-mediated killing and protection by anti-CPS antibodies. The relative failure of ST3 PCV may be due to CPS release, suggesting that alternative immunization approaches for ST3 may be necessary.

  15. Capsular Polysaccharide (CPS) Release by Serotype 3 Pneumococcal Strains Reduces the Protective Effect of Anti-Type 3 CPS Antibodies

    PubMed Central

    Choi, Eun Hwa; Zhang, Fan; Lu, Ying-Jie

    2015-01-01

    The efficacy of the serotype 3 (ST3) pneumococcal conjugate vaccine (PCV) remains unclear. While the synthesis of capsular polysaccharide (CPS) of most serotypes is wzy dependent, the strains of two serotypes, 3 and 37, synthesize CPS by the synthase-dependent pathway, resulting in a polysaccharide that is not covalently linked to peptidoglycan and can be released during growth. We hypothesized that the release of CPS during growth reduces anti-type 3 CPS antibody-mediated protection and may explain the lower efficacy of the type 3 component of PCV than that of other PCVs. The in vitro-released CPS concentrations per 107 CFU of ST3 and ST37 strains were significantly higher than those for the ST1, ST4, ST6B, and ST14 strains. Following intraperitoneal (i.p.) injection in mice, blood concentrations of CPS were significantly higher for the ST3 than for the ST4/5 strains. The opsonophagocytic killing assay (OPKA) titer of anti-type 3 CPS antibody was significantly reduced by type 3 CPS, culture supernatant, or serum from Streptococcus pneumoniae ST3 strain WU2-infected mice. Mice were injected with capsule-specific antibodies and challenged i.p. with or without the addition of sterile culture supernatant containing type-specific CPS. The addition of 0.2 μl of culture supernatant from WU2 inhibited passive protection, whereas 100-fold-more culture supernatant from S. pneumoniae ST4 strain TIGR4 was required for the inhibition of protection. We conclude that released type 3 CPS interferes with antibody-mediated killing and protection by anti-CPS antibodies. The relative failure of ST3 PCV may be due to CPS release, suggesting that alternative immunization approaches for ST3 may be necessary. PMID:26677201

  16. Complex Population Structure and Virulence Differences among Serotype 2 Streptococcus suis Strains Belonging to Sequence Type 28

    PubMed Central

    Athey, Taryn B. T.; Auger, Jean-Philippe; Teatero, Sarah; Dumesnil, Audrey; Takamatsu, Daisuke; Wasserscheid, Jessica; Dewar, Ken; Gottschalk, Marcelo; Fittipaldi, Nahuel

    2015-01-01

    Streptococcus suis is a major swine pathogen and a zoonotic agent. Serotype 2 strains are the most frequently associated with disease. However, not all serotype 2 lineages are considered virulent. Indeed, sequence type (ST) 28 serotype 2 S. suis strains have been described as a homogeneous group of low virulence. However, ST28 strains are often isolated from diseased swine in some countries, and at least four human ST28 cases have been reported. Here, we used whole-genome sequencing and animal infection models to test the hypothesis that the ST28 lineage comprises strains of different genetic backgrounds and different virulence. We used 50 S. suis ST28 strains isolated in Canada, the United States and Japan from diseased pigs, and one ST28 strain from a human case isolated in Thailand. We report a complex population structure among the 51 ST28 strains. Diversity resulted from variable gene content, recombination events and numerous genome-wide polymorphisms not attributable to recombination. Phylogenetic analysis using core genome single-nucleotide polymorphisms revealed four discrete clades with strong geographic structure, and a fifth clade formed by US, Thai and Japanese strains. When tested in experimental animal models, strains from this latter clade were significantly more virulent than a Canadian ST28 reference strain, and a closely related Canadian strain. Our results highlight the limitations of MLST for both phylogenetic analysis and virulence prediction and raise concerns about the possible emergence of ST28 strains in human clinical cases. PMID:26375680

  17. Unconventional Recombination in the Mating Type Locus of Heterothallic Apple Canker Pathogen Valsa mali

    PubMed Central

    Yin, Zhiyuan; Ke, Xiwang; Li, Zhengpeng; Chen, Jiliang; Gao, Xiaoning; Huang, Lili

    2017-01-01

    Sexual reproduction in filamentous ascomycetes is controlled by the mating type (MAT) locus, including two idiomorphs MAT1-1 and MAT1-2. Understanding the MAT locus can provide clues for unveiling the sexual development and virulence factors for fungal pathogens. The genus Valsa (Sordariomycetes, Diaporthales) contains many tree pathogens responsible for destructive canker diseases. The sexual stage of these ascomycetes is occasionally observed in nature, and no MAT locus has been reported to date. Here, we identified the MAT locus of the apple canker pathogen Valsa mali, which causes extensive damage, and even death, to trees. V. mali is heterothallic in that each isolate carries either the MAT1-1 or MAT1-2 idiomorph. However, the MAT structure is distinct from that of many other heterothallic fungi in the Sordariomycetes. Two flanking genes, COX13 and APN2, were coopted into the MAT locus, possibly by intrachromosomal rearrangement. After the acquisition of foreign genes, unequal recombination occurred between MAT1-1/2 idiomorphs, resulting in a reverse insertion in the MAT1-2 idiomorph. Evolutionary analysis showed that the three complete MAT1-1-2, COX13, and APN2 genes in this region diverged independently due to different selection pressure. Null hypothesis tests of a 1:1 MAT ratio of 86 V. mali isolates from four different provinces showed a relatively balanced distribution of the two idiomorphs in the fields. These results provide insights into the evolution of the mating systems in Sordariomycetes. PMID:28228472

  18. Mating Type and Simple Sequence Repeat Markers Indicate a Clonal Population of Phyllosticta citricarpa in Florida.

    PubMed

    Wang, Nan-Yi; Zhang, Ke; Huguet-Tapia, Jose C; Rollins, Jeffrey A; Dewdney, Megan M

    2016-11-01

    Phyllosticta citricarpa, the citrus black spot pathogen, was first identified in Florida in March 2010. Subsequently, this pathogen has become established in Florida but can be easily confused with the endemic nonpathogenic citrus endophyte P. capitalensis. In this study, the mating-type (MAT) loci of P. citricarpa and P. capitalensis were identified via draft genome sequencing and were characterized at the structural and sequence levels. P. citricarpa was determined to have an idiomorphic, heterothallic MAT locus structure, whereas P. capitalensis was found to have a single MAT locus consistent with a homothallic mating system. A survey of P. citricarpa isolates from Florida revealed that only the MAT1-2 idiomorph existed in the Floridian population. In contrast, isolates collected from Australia exhibited a 1:1 ratio of MAT1-1 and MAT1-2 isolates. Development and analysis of simple sequence repeat markers revealed a single multilocus genotype (MLG) in the Floridian population (n = 70) and 11 MLG within the Australian population (n = 24). These results indicate that isolates of P. citricarpa from Florida are likely descendent from a single clonal lineage and are reproducing asexually. The disease management focus in Florida will need to be concentrated on the production and dispersal of pycnidiospores.

  19. Genetic structure of the mating-type locus of Chlamydomonas reinhardtii.

    PubMed Central

    Ferris, Patrick J; Armbrust, E Virginia; Goodenough, Ursula W

    2002-01-01

    Portions of the cloned mating-type (MT) loci (mt(+) and mt(-)) of Chlamydomonas reinhardtii, defined as the approximately 1-Mb domains of linkage group VI that are under recombinational suppression, were subjected to Northern analysis to elucidate their coding capacity. The four central rearranged segments of the loci were found to contain both housekeeping genes (expressed during several life-cycle stages) and mating-related genes, while the sequences unique to mt(+) or mt(-) carried genes expressed only in the gametic or zygotic phases of the life cycle. One of these genes, Mtd1, is a candidate participant in gametic cell fusion; two others, Mta1 and Ezy2, are candidate participants in the uniparental inheritance of chloroplast DNA. The identified housekeeping genes include Pdk, encoding pyruvate dehydrogenase kinase, and GdcH, encoding glycine decarboxylase complex subunit H. Unusual genetic configurations include three genes whose sequences overlap, one gene that has inserted into the coding region of another, several genes that have been inactivated by rearrangements in the region, and genes that have undergone tandem duplication. This report extends our original conclusion that the MT locus has incurred high levels of mutational change. PMID:11805055

  20. Drug Resistance Is Not Directly Affected by Mating Type Locus Zygosity in Candida albicans

    PubMed Central

    Pujol, Claude; Messer, Shawn A.; Pfaller, Michael; Soll, David R.

    2003-01-01

    Recently, evidence was presented that in a collection of fluconazole-resistant strains of Candida albicans there was a much higher proportion of homozygotes for the mating type locus (MTL) than in a collection of fluconazole-sensitive isolates, suggesting the possibility that when cells become MTL homozygous they acquire intrinsic drug resistance. To investigate this possibility, an opposite strategy was employed. First, drug susceptibility was measured in a collection of isolates selected for MTL homozygosity. The majority of these isolates had not been exposed to antifungal drugs. Second, the level of drug susceptibility was compared between spontaneously generated MTL-homozygous progeny and their MTL-heterozygous parent strains which had not been exposed to antifungal drugs. The results demonstrate that naturally occurring MTL-homozygous strains are not intrinsically more drug resistant, supporting the hypotheses that either the higher incidence of MTL homozygosity previously demonstrated among fluconazole-resistant isolates involved associated homozygosity of a drug resistance gene linked to the MTL locus, or that MTL-homozygous strains may be better at developing drug resistance upon exposure to the drug than MTL-heterozygous strains. Furthermore, the results demonstrate that a switch by an MTL-homozygous strain from the white to opaque phenotype, the latter functioning as the facilitator of mating, does not notably alter drug susceptibility. PMID:12654648

  1. Identification and In Situ Distribution of a Fungal Gene Marker: The Mating Type Genes of the Black Truffle.

    PubMed

    De la Varga, Herminia; Murat, Claude

    2016-01-01

    Truffles are ectomycorrhizal fungi harvested mainly in human managed agroforestry ecosystems. Truffle production in truffle orchards faces two important bottlenecks or challenges: the initiation of the sexual reproduction and the growth of the ascocarps during several months. The black Périgord truffle, Tuber melanosporum, is a heterothallic species and the mating type genes (MAT1-1 and M1T1-2) have been characterized. In this context, the unraveling of the T. melanosporum mating type strains distribution in truffle orchards is a critical starting point to provide new insights into its sexual reproduction. The aim of this chapter is to present the protocol used to characterize the T. melanosporum mating type present in a truffle orchard from ascocarps, hazel mycorrhizal root tips, and/or soil samples, by polymerase chain reactions using specific primers for those genes, but it can be adapted for other fungal species.

  2. Hemolysin and K antigens in relation to serotype and hemagglutination type of Escherichia coli isolated from extraintestinal infections.

    PubMed Central

    Evans, D J; Evans, D G; Höhne, C; Noble, M A; Haldane, E V; Lior, H; Young, L S

    1981-01-01

    Escherichia coli isolated from cases of bacteremia and from a variety of urinary tract infections were characterized according to serotype (O:H antigenicity), K type (possession of K1, K2, K3, K12, or K13), hemagglutination (HA) type, and production of beta-hemolysin. Results obtained with the bacteremia and urinary tract infection isolates were similar except for more hemolytic isolated from urine than from blood (42 versus 29%) and more K1+ isolates from blood than from urine (50 versus 29%). A close correlation was found between Ha type VI (production of fimbriae which mediate mannose-resistant HA of human and African green monkey erythrocytes) and the production of hemolysin or K1 capsular antigen or both. Most (95 of 98, or 95%) of the HA type VI+ blood isolates and most (146 of 164, or 89%) of the HA type VI+ urine isolates produced hemolysin or K1 or both, in contrast to 22 and 26%, respectively, of those belonging to HA types other than HA type VI. Also, 76% of all hemolytic and 70% of all K1+ isolates belonged to HA type VI. Remarkably few of the HA type VI+ isolates (13%) and even fewer of the HA type VI- isolates (3%) produced both K1 and hemolysin; these belonged mainly to serotypes O16:H6, O18:H7 and O2:H4. Other major serogroups were usually K1+/hemolysin- (O1, O7) or K1-/hemolysin+ (O2, O4, O6). At least 74% (262 of 351) and possibly as many as 83% (293 of 351) of those isolates which produced mannose-resistant HA of human erythrocytes were classified as HA type VI+; 31 isolates produced mannose-resistant HA with all erythrocytes tested. Taking serogroup and serotype into consideration, we conclude that the E. coli fimbrial hemagglutinin(s) responsible for the HA type VI phenotype will prove to be the same as the virulence-associated mannose-resistant adhesins of uropathogenic E. coli which other investigators have characterized as unique fimbrial antigens detectable by mannose-resistant HA of human erythrocytes. PMID:7007421

  3. The DNA Repair Protein yKu80 Regulates the Function of Recombination Enhancer during Yeast Mating Type Switching†

    PubMed Central

    Ruan, Chun; Workman, Jerry L.; Simpson, Robert T.

    2005-01-01

    Recombination enhancer (RE) is essential for regulating donor preference during yeast mating type switching. In this study, by using minichromosome affinity purification (MAP) and mass spectrometry, we found that yeast Ku80p is associated with RE in MATa cells. Chromatin immunoprecipitation assays confirmed its occupancy in vivo. Deletion of YKU80 results in altered chromatin structure in the RE region and more importantly causes a dramatic decrease of HML usage in MATa cells. We also detect directional movement of yKu80p from the RE towards HML during switching. These results indicate a novel function of yeast Ku80p in regulating mating type switching. PMID:16166630

  4. A MAT1–2 wild-type strain from Penicillium chrysogenum: functional mating-type locus characterization, genome sequencing and mating with an industrial penicillin-producing strain

    PubMed Central

    Böhm, Julia; Dahlmann, Tim A; Gümüşer, Hendrik; Kück, Ulrich

    2015-01-01

    In heterothallic ascomycetes, mating is controlled by two nonallelic idiomorphs that determine the ‘sex’ of the corresponding strains. We recently discovered mating-type loci and a sexual life cycle in the penicillin-producing fungus, Penicillium chrysogenum. All industrial penicillin production strains worldwide are derived from a MAT1-1 isolate. No MAT1-2 strain has been investigated in detail until now. Here, we provide the first functional analysis of a MAT1-2 locus from a wild-type strain. Similar to MAT1-1, the MAT1-2 locus has functions beyond sexual development. Unlike MAT1-1, the MAT1-2 locus affects germination and surface properties of conidiospores and controls light-dependent asexual sporulation. Mating of the MAT1-2 wild type with a MAT1-1 high penicillin producer generated sexual spores. We determined the genomic sequences of parental and progeny strains using next-generation sequencing and found evidence for genome-wide recombination. SNP calling showed that derived industrial strains had an uneven distribution of point mutations compared with the wild type. We found evidence for meiotic recombination in all chromosomes. Our results point to a strategy combining the use of mating-type genes, genetics, and next-generation sequencing to optimize conventional strain improvement methods. PMID:25521009

  5. Molecular organization of the mating-type loci in the homothallic Ascomycete Eupenicillium crustaceum.

    PubMed

    Pöggeler, Stefanie; O'Gorman, Céline M; Hoff, Birgit; Kück, Ulrich

    2011-07-01

    Eupenicillium species are the teleomorphic (sexual) forms of anamorphic (asexual) members of the genus Penicillium, which contains many species of industrial importance. Here we describe the first molecular analysis of the mating-type (MAT) locus from a homothallic (self-fertile) Eupenicillium species, E. crustaceum. This ascomycete is a sexual relative of the penicillin producer Penicillium chrysogenum, which while long considered asexual, was recently shown to possess the required genetic machinery for heterothallic breeding. The E. crustaceum genome contains two MAT loci, MAT1-1 and MAT1-2, in an arrangement characteristic of other known homothallic euascomycetes, such as Neosartorya fischeri. MAT1-1 is flanked by conserved APN2 (DNA lyase) and SLA2 (cytoskeleton assembly control) genes and encodes a homologue of the α-box domain protein MAT1-1-1. Conversely, MAT1-2 carries a HMG-domain gene MAT1-2-1, and is flanked by a degenerate SLA2 gene and an intact homologue of the P. chrysogenum ORF Pc20g08960. Here we demonstrate the transcriptional expression of both mating-type genes during vegetative development. Furthermore, the MAT1-1-1 and MAT1-2-1 sequences were used to resolve the phylogenetic relationship of E. crustaceum with other ascomycetes. Phylogenetic trees confirmed a very close relationship between the homothallic E. crustaceum and the supposedly heterothallic P. chrysogenum. This close taxonomic association makes E. crustaceum an ideal candidate for future expression and evolutionary studies of sexual reproduction, with the ultimate aim of inducing sex in P. chrysogenum.

  6. Stringent mating-type-regulated auxotrophy increases the accuracy of systematic genetic interaction screens with Saccharomyces cerevisiae mutant arrays.

    PubMed

    Singh, Indira; Pass, Rebecca; Togay, Sine Ozmen; Rodgers, John W; Hartman, John L

    2009-01-01

    A genomic collection of haploid Saccharomyces cerevisiae deletion strains provides a unique resource for systematic analysis of gene interactions. Double-mutant haploid strains can be constructed by the synthetic genetic array (SGA) method, wherein a query mutation is introduced by mating to mutant arrays, selection of diploid double mutants, induction of meiosis, and selection of recombinant haploid double-mutant progeny. The mechanism of haploid selection is mating-type-regulated auxotrophy (MRA), by which prototrophy is restricted to a particular haploid genotype generated only as a result of meiosis. MRA escape leads to false-negative genetic interaction results because postmeiotic haploids that are supposed to be under negative selection instead proliferate and mate, forming diploids that are heterozygous at interacting loci, masking phenotypes that would be observed in a pure haploid double-mutant culture. This work identified factors that reduce MRA escape, including insertion of terminator and repressor sequences upstream of the MRA cassette, deletion of silent mating-type loci, and utilization of alpha-type instead of a-type MRA. Modifications engineered to reduce haploid MRA escape reduced false negative results in SGA-type analysis, resulting in >95% sensitivity for detecting gene-gene interactions.

  7. Incidence of childhood pneumonia and serotype and sequence-type distribution in Streptococcus pneumoniae isolates in Japan.

    PubMed

    Tanaka, J; Ishiwada, N; Wada, A; Chang, B; Hishiki, H; Kurosaki, T; Kohno, Y

    2012-06-01

    The 7-valent pneumococcal conjugate vaccine (PCV7) is reported to decrease the incidence of community-acquired pneumonia (CAP) in children. To determine the annual incidence of CAP before the introduction of PCV7, we counted the number of children hospitalized with CAP between 2008 and 2009 in Chiba City, Japan. We investigated serotype and multilocus sequence typing (MLST) for Streptococcus pneumoniae isolates in CAP cases. The annual incidence of hospitalized CAP in children aged <5 years was 17.6 episodes/1000 child-years. In 626 episodes, S. pneumoniae was dominant in 14.7% and 0.8% of sputum and blood samples, respectively. The most common serotypes were 6B, 23F and 19F. The coverage rates of PCV7 were 66.7% and 80% in sputum samples and blood samples, respectively. MLST analysis revealed 37 sequence types. Furthermore, 54.1% of the sputum isolates and 40% of the blood isolate were related to international multidrug-resistant clones.

  8. Mating-type distribution and genetic diversity of Cercospora sojina populations on soybean from Arkansas: evidence for potential sexual reproduction.

    PubMed

    Kim, Hun; Newell, Annakay D; Cota-Sieckmeyer, Robyn G; Rupe, John C; Fakhoury, Ahmad M; Bluhm, Burton H

    2013-10-01

    Cercospora sojina causes frogeye leaf spot of soybean, which can cause serious economic losses in the United States. In this study, 132 C. sojina isolates were collected from six fields (from two counties, Cross and Crawford) in Arkansas. To determine mating type, a multiplex polymerase chain reaction assay was developed with primers specific for C. sojina. Of the 132 isolates, 68 isolates had the MAT1-1-1 idiomorph and 64 isolates had the MAT1-2 idiomorph; no isolates possessed both idiomorphs. Both mating types were present in a variety of spatial scales, including separate lesions on individual leaves. Clone-corrected data from eight microsatellites indicated that mating-type loci were present in approximately equal proportions in all populations analyzed, which suggests that Arkansas populations of C. sojina are undergoing cryptic sexual reproduction. All six populations evaluated had high genotypic diversity of 26 to 79%. In addition, among strains isolated from a single leaf, multiple and distinct haplotypes were associated with both mating types, supporting the hypothesis that sexual reproduction occurs within the populations. Most populations showed significant gametic disequilibrium but levels of disequilibrium were relatively low, particularly in populations from Crawford County. A low differentiation index (GST) was observed for all simple-sequence repeat markers across all populations. Furthermore, the value of G statistics between populations suggests that significant genetic exchange exists among the populations. Taken together, these results demonstrate that C. sojina populations from Arkansas are genetically diverse and most likely undergoing sexual reproduction.

  9. Characterization of Ascochyta rabiei for population structure, mating type and pathogenic variability from Pakistan and United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chickpea production is greatly hampered by blight causing fungal pathogen Ascochyta rabiei (AR) in chickpea growing regions of the world. Genetic variability and mating type frequency of thirty-two AR isolates from six geographical regions of Pakistan were compared with a US-AR population. Pakistani...

  10. A multiplex PCR assay for determination of mating type in isolates of the honey bee fungal pathogen, Ascosphaera apis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study we developed a multiplex PCR for identification of mating type idiomorphs in the filamentous fungus, Ascosphaera apis, the causative agent of chalkbrood disease in the honey bee (Apis melliffera). A combination of gene-specific primers was designed to amplify Mat1-1 and Mat1-2 gene fra...

  11. The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes

    PubMed Central

    Elías-Villalobos, Alberto; Fernández-Álvarez, Alfonso; Moreno-Sánchez, Ismael; Helmlinger, Dominique; Ibeas, José I.

    2015-01-01

    Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs) play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis. PMID:26317403

  12. Computerized restriction endonuclease analysis compared with O-serotype and phage type in the epidemiologic fingerprinting of Pseudomonas aeruginosa strains.

    PubMed

    Garaizar, Javier; Latorre, Mikel; López-Molina, Nuria; Laconcha, Idoia; Alberdi, Leire; Rementeria, Aitor; Audicana, Ana; Uliarte, Rosario; Cisterna, Ramón

    1997-04-01

    OBJECTIVE: To assess restriction endonuclease analysis (REA) of chromosomal DNA using SalI enzyme, low-concentration (0.4%) agarose gels and digitalized data management of the REA patterns obtained for the typing of clinical Pseudomonas aeruginosa isolates. METHODS: A group of 67 clinical unrelated isolates from 10 Spanish hospitals was used to study the discriminatory power, reproducibility and typeability of REA typing. RESULTS: A SalI REA pattern consisted of a variety (1--10) of restriction bands in the range between 12.2 and 48.5 kb and an unresolvable smear of low-molecular-weight bands. Forty different SalI REA patterns with an index of discrimination of 0.979 were obtained. Low typeability (91.04%) was the major limitation of REA typing. Analysis of blinded subcultures of eight Pseudomonas aeruginosa strains showed the reproducibility of REA typing to be 87.5%. Combined phenotypic typing (O-serotyping and phage typing) performed on the same group of strains showed comparable discrimination but much lower reproducibility. Isolates selected from five clusters of nosocomial infections in hospitals in the UK were typed by REA typing, and the results show high agreement when compared with conventional phenotypic typing methods in distinguishing between strains. CONCLUSIONS: These data underline the usefulness of REA typing enhanced with digitalized data management for the epidemiologic subtyping of clinical Pseudomonas aeruginosa isolates.

  13. Mating Type Gene (MAT) and Itraconazole Susceptibility of Trichophyton tonsurans Strains Isolated in Japan.

    PubMed

    Hiruma, Junichiro; Okubo, Miki; Kano, Rui; Kumagawa, Mai; Hiruma, Masataro; Hasegawa, Atsuhiko; Kamata, Hiroshi; Tsuboi, Ryoji

    2016-06-01

    Infection by Trichophyton tonsurans is an emerging fungal epidemic in Japan. Itraconazole (ITZ) and terbinafine have been used for the treatment of this infection for 15 years. However, patients with T. tonsurans infections have been shown to remain uncured or to become reinfected, suggesting that subclinical infection or polyphyletic strains and/or antifungal drug-resistant strains might be occurring in Japan. In this study, PCR analysis was performed to confirm the presence of the mating type locus MAT in genomic DNA from 60 Japanese clinical isolates of T. tonsurans, and to assess the previously postulated clonal origin of clinical isolates of this species. Antifungal susceptibility testing on isolates also was performed to confirm the absence of strains resistant to ITZ. PCR analysis proved that all 60 strains contained the MAT1-1 allele, while none contained the MAT1-2 allele. As determined by E-test, the mean MIC of ITZ in the 60 strains was 0.023 mg/L (range 0.002-0.125 mg/L). All strains of T. tonsurans isolated in Japan were clonal and were not resistant to ITZ. Therefore, dermatophytosis due to T. tonsurans is expected to respond to ITZ, since clinical isolates of T. tonsurans tested to date have been susceptible to this antifungal. This infection is proliferating as a subclinical infection in Japan.

  14. Local Outbreak of Listeria monocytogenes Serotype 4b Sequence Type 6 Due to Contaminated Meat Pâté.

    PubMed

    Althaus, Denise; Jermini, Marco; Giannini, Petra; Martinetti, Gladys; Reinholz, Danuta; Nüesch-Inderbinen, Magdalena; Lehner, Angelika; Stephan, Roger

    2017-04-01

    In January and February 2016, five cases of confirmed and two cases of probable infection due to Listeria monocytogenes serotype 4b, sequence type (ST) 6 belonging to a single pulsed-field gel electrophoresis pulsotype pattern were registered in a region of southern Switzerland. L. monocytogenes was detected in blood samples (four cases) and pleural fluid (one case). Furthermore, L. monocytogenes 4b ST6 was detected in a stool sample of an asymptomatic person exposed to a common food. Forthwith, the food safety authority and a local gourmet meat producer reported L. monocytogenes contamination of meat pâté. Analysis of further food and environmental samples from the premises of the producer yielded isolates matching the clinical strains and confirmed the presence of L. monocytogenes 4b ST6 in the mincing machine as the cause of the food contamination.

  15. Emergence of KPC-producing Klebsiella pneumoniae hypervirulent clone of capsular serotype K1 that belongs to sequence type 11 in Mainland China.

    PubMed

    Wei, Dan-Dan; Wan, La-Gen; Deng, Qiong; Liu, Yang

    2016-06-01

    KPC-2 has been rarely reported in hypervirulent Klebsiella pneumoniae strains. Here, we describe a KPC-2-producing K. pneumoniae hypervirulent clone of capsular serotype K1 belonging to sequence type 11. The presence of KPC carbapenemase in hypervirulent clone could mark an evolutionary step toward its establishment as major nosocomial pathogen.

  16. Population structure of hyperinvasive serotype 12F, clonal complex 218 Streptococcus pneumoniae revealed by multilocus boxB sequence typing

    PubMed Central

    Rakov, Alexey V.; Ubukata, Kimiko; Robinson, D. Ashley

    2011-01-01

    At least four outbreaks of invasive disease caused by serotype 12F, clonal complex 218 Streptococcus pneumoniae have occurred in the United States over the past two decades. We studied the population structure of this clonal complex using a sample of 203 outbreak and surveillance isolates that were collected over 22 years from 34 US states and eight other countries. Conventional multilocus sequence typing identified five types and distinguished a single outbreak from the others. To improve typing resolution, multilocus boxB sequence typing (MLBT) was developed from 10 variable boxB minisatellite loci. MLBT identified 86 types and distinguished between each of the four outbreaks. Diversity across boxB loci tended to be positively correlated with repeat array size and, overall, best fit the infinite alleles mutation model. Multilocus linkage disequilibrium was strong, but pairwise disequilibrium decreased with the physical distance between loci and was strongest in one large region of the chromosome, indicating recent recombinations. Two major clusters were identified in the sample, and they were differentiated geographically, as western and more easterly US clusters, and temporally, as clusters that predominated before and after the licensure of pneumococcal conjugate vaccines. The diversity and linkage disequilibrium within these two clusters also differed, suggesting different population dynamics. MLBT revealed hidden aspects of the population structure of these hyperinvasive pneumococci, and it may provide a useful adjunct tool for outbreak investigations, surveillance, and population genetics studies of other pneumococcal clonal complexes. PMID:21888992

  17. [Surveillance of Haemophilus influenzae serotypes in Argentina from 2005 to 2010 during the Haemophilus influenzae type b conjugate vaccine era].

    PubMed

    Efron, Adriana M; Moscoloni, María A; Reijtman, Vanesa R; Regueira, Mabel

    2013-01-01

    The introduction of the Haemophilus influenzae type b vaccine in the immunization programs of many countries has greatly reduced this invasive disease and the carriage caused by this serotype, also increasing other capsular types and non-capsular isolations. There were 313 isolations of H. influenzae under study, which were recovered from a sterile site coming from pediatric and adult patients carrying the invasive disease. Patients were treated at 90 different hospitals belonging to the Red Nacional de Laboratorios para Meningitis e Infecciones Respiratorias Agudas Bacterianas (National Lab Network for Meningitis and Acute Bacterial Respiratory Infections) from 2005 to 2010 for the following disorders: pneumonia, 40.3% (n=126), meningitis, 30.0% (n=94) and bacteremia, 26.5% (n=83). In pediatric patients (n=279), the highest frequency of isolations corresponded to children under the age of 2 years, 74.5% (n=208). Regarding type distribution, 61.3% corresponded to non-capsular H. influenzae (n=192), 20.1% to type b (n=63), 11.2% to type a (n=35), 4.8% to type f, and 2.6% to other types. Capsular H. influenzae was predominant in meningitis whereas non-capsular H. influenzae in pneumonia and bacteremia. The biotype was determined in 306 isolations. The totality (100%) of type a (n=35) was biotype II whereas 66.7% of type b (n=63) was biotype I. Slide agglutination and PCR tests were used in 220 isolations. There was a match of 0.982 (IC: 0.92-1.00) between them. During the last year, there was a great increase in type b, showing the importance of clinical and laboratory-based surveillance of the invasive disease caused by H. influenzae.

  18. Isolation site influences virulence phenotype of serotype 14 Streptococcus pneumoniae strains belonging to multilocus sequence type 15.

    PubMed

    Amin, Zarina; Harvey, Richard M; Wang, Hui; Hughes, Catherine E; Paton, Adrienne W; Paton, James C; Trappetti, Claudia

    2015-12-01

    Streptococcus pneumoniae is a diverse species causing invasive as well as localized infections that result in massive global morbidity and mortality. Strains vary markedly in pathogenic potential, but the molecular basis is obscured by the diversity and plasticity of the pneumococcal genome. We have previously reported that S. pneumoniae serotype 3 isolates belonging to the same multilocus sequence type (MLST) differed markedly in in vitro and in vivo phenotypes, in accordance with the clinical site of isolation, suggesting stable niche adaptation within a clonal lineage. In the present study, we have extended our analysis to serotype 14 clinical isolates from cases of sepsis or otitis media that belong to the same MLST (ST15). In a murine intranasal challenge model, five ST15 isolates (three from blood and two from ears) colonized the nasopharynx to similar extents. However, blood and ear isolates exhibited significant differences in bacterial loads in other host niches (lungs, ear, and brain) at both 24 and 72 h postchallenge. In spite of these differences, blood and ear isolates were present in the lungs at similar levels at 6 h postchallenge, suggesting that early immune responses may underpin the distinct virulence phenotypes. Transcriptional analysis of lung tissue from mice infected for 6 h with blood isolates versus ear isolates revealed 8 differentially expressed genes. Two of these were exclusively expressed in response to infection with the ear isolate. These results suggest a link between the differential capacities to elicit early innate immune responses and the distinct virulence phenotypes of clonally related S. pneumoniae strains.

  19. Deciphering evolutionary strata on plant sex chromosomes and fungal mating-type chromosomes through compositional segmentation.

    PubMed

    Pandey, Ravi S; Azad, Rajeev K

    2016-03-01

    Sex chromosomes have evolved from a pair of homologous autosomes which differentiated into sex determination systems, such as XY or ZW system, as a consequence of successive recombination suppression between the gametologous chromosomes. Identifying the regions of recombination suppression, namely, the "evolutionary strata", is central to understanding the history and dynamics of sex chromosome evolution. Evolution of sex chromosomes as a consequence of serial recombination suppressions is well-studied for mammals and birds, but not for plants, although 48 dioecious plants have already been reported. Only two plants Silene latifolia and papaya have been studied until now for the presence of evolutionary strata on their X chromosomes, made possible by the sequencing of sex-linked genes on both the X and Y chromosomes, which is a requirement of all current methods that determine stratum structure based on the comparison of gametologous sex chromosomes. To circumvent this limitation and detect strata even if only the sequence of sex chromosome in the homogametic sex (i.e. X or Z chromosome) is available, we have developed an integrated segmentation and clustering method. In application to gene sequences on the papaya X chromosome and protein-coding sequences on the S. latifolia X chromosome, our method could decipher all known evolutionary strata, as reported by previous studies. Our method, after validating on known strata on the papaya and S. latifolia X chromosome, was applied to the chromosome 19 of Populus trichocarpa, an incipient sex chromosome, deciphering two, yet unknown, evolutionary strata. In addition, we applied this approach to the recently sequenced sex chromosome V of the brown alga Ectocarpus sp. that has a haploid sex determination system (UV system) recovering the sex determining and pseudoautosomal regions, and then to the mating-type chromosomes of an anther-smut fungus Microbotryum lychnidis-dioicae predicting five strata in the non

  20. Organization and Evolutionary Trajectory of the Mating Type (MAT) Locus in Dermatophyte and Dimorphic Fungal Pathogens▿ †

    PubMed Central

    Li, Wenjun; Metin, Banu; White, Theodore C.; Heitman, Joseph

    2010-01-01

    Sexual reproduction in fungi is governed by a specialized genomic region, the mating type (MAT) locus, whose gene identity, organization, and complexity are diverse. We identified the MAT locus of five dermatophyte fungal pathogens (Microsporum gypseum, Microsporum canis, Trichophyton equinum, Trichophyton rubrum, and Trichophyton tonsurans) and a dimorphic fungus, Paracoccidioides brasiliensis, and performed phylogenetic analyses. The identified MAT locus idiomorphs of M. gypseum control cell type identity in mating assays, and recombinant progeny were produced. Virulence tests in Galleria mellonella larvae suggest the two mating types of M. gypseum may have equivalent virulence. Synteny analysis revealed common features of the MAT locus shared among these five dermatophytes: namely, a small size (∼3 kb) and a novel gene arrangement. The SLA2, COX13, and APN2 genes, which flank the MAT locus in other Ascomycota are instead linked on one side of the dermatophyte MAT locus. In addition, the transcriptional orientations of the APN2 and COX13 genes are reversed compared to the dimorphic fungi Histoplasma capsulatum, Coccidioides immitis, and Coccidioides posadasii. A putative transposable element, pogo, was found to have inserted in the MAT1-2 idiomorph of one P. brasiliensis strain but not others. In conclusion, the evolution of the MAT locus of the dermatophytes and dimorphic fungi from the last common ancestor has been punctuated by both gene acquisition and expansion, and asymmetric gene loss. These studies further support a foundation to develop molecular and genetic tools for dermatophyte and dimorphic human fungal pathogens. PMID:19880755

  1. Gametogenesis in the Chlamydomonas reinhardtii minus mating type is controlled by two genes, MID and MTD1.

    PubMed

    Lin, Huawen; Goodenough, Ursula W

    2007-06-01

    In the unicellular algae Chlamydomonas reinhardtii, the plus and minus mating types are controlled by a complex locus, MT, where the dominant MID gene in the MT(-) locus has been shown to be necessary for expression of minus-specific gamete-specific genes in response to nitrogen depletion. We report studies on MID expression patterns during gametogenesis and on a second gene unique to the MT(-) locus, MTD1. Vegetative cells express basal levels of MID. An early activation of MID transcription after nitrogen removal, and its sequence similarity to plant RWP-RK proteins involved in nitrogen-responsive processes, suggest that Mid conformation/activity may be nitrogen sensitive. A second stage of MID upregulation correlates with the acquisition of mating ability in minus gametes. Knockdown of MTD1 by RNAi in minus strains results in a failure to differentiate into gametes of either mating type after nitrogen deprivation. We propose that intermediate Mid levels are sufficient to activate MTD1 transcription and to repress plus gamete-specific genes and that MTD1 expression in turn allows the threshold-level MID expression needed to turn on minus gamete-specific genes. We further propose that an MTD1-equivalent system, utilizing at least one gene product encoded in the MT(+) locus, is operant during plus gametogenesis.

  2. A sex recognition glycoprotein is encoded by the plus mating-type gene fus1 of Chlamydomonas reinhardtii.

    PubMed Central

    Ferris, P J; Woessner, J P; Goodenough, U W

    1996-01-01

    Sexual fusion between plus and minus gametes of the unicellular green alga Chlamydomonas reinhardtii entails adhesion between plus-specific and minus-specific "fringe" proteins displayed on the plasma membrane of gametic mating structures. We report the identification of the gene (fus1) encoding the plus fringe glycoprotein, which resides in a unique domain of the mating-type plus (mt+) locus, and which was identified by transposon insertions in three fusion-defective mutant strains. Transformation with fus1+ restores fringe and fusion competence to these mutants and to the pseudo-plus mutant imp11 mt-, defective in minus differentiation. The fus1 gene is remarkable in lacking the codon bias found in all other nuclear genes of C. reinhardtii. Images PMID:8856667

  3. DNA vaccine encoding type IV pilin of Actinobacillus pleuropneumoniae induces strong immune response but confers limited protective efficacy against serotype 2 challenge.

    PubMed

    Lu, Yu-Chun; Li, Min-Chen; Chen, Yi-Min; Chu, Chun-Yen; Lin, Shuen-Fuh; Yang, Wen-Jen

    2011-10-13

    Actinobacillus pleuropneumoniae is a gram-negative bacterial pathogen that causes swine pleuropneumonia, a highly contagious and often fatal disease that occurs worldwide. Our previous study showed that DNA vaccines encoding Apx exotoxin structural proteins ApxIA and/or ApxIIA, are a promising novel approach for immunization against the lethal challenge of A. pleuropneumoniae serotype 1. Vaccination against A. pleuropneumoniae is impeded by the lack of vaccines inducing reliable cross-serotype protection. Type IV fimbrial protein ApfA has been shown to be present and highly conserved in various serotypes of A. pleuropneumoniae. A novel DNA vaccine encoding ApfA (pcDNA-apfA) was constructed to evaluate the protective efficacy against infection with A. pleuropneumoniae serotype 2. A significant antibody response against pilin was generated following pcDNA-apfA immunization, suggesting that it was expressed in vivo. The IgG subclass (IgG1 and IgG2a) analysis indicates that the pcDNA-apfA vaccine induces both Th1 and Th2 immune responses. The IgA analysis shows that mucosal immunity could be enhanced by this DNA vaccine. Nevertheless, the strong antibody response induced by pcDNA-apfA vaccine only provided limited 30% protective efficacy against the serotype 2 challenge. These results in this study do not coincide with that the utility of type IV pilin is a good vaccine candidate against other infectious pathogens. It indicates that pilin should play a limited role in the development of a vaccine against A. pleuropneumoniae infection.

  4. Cryptococcus neoformans, Cryptococcus gattii: serotypes in Venezuela.

    PubMed

    Pérez, C; Dolande, M; Moya, M; Roselló, A; de Capriles, Claudia R Hartung; Landaeta, M E; Mata-Essayag, S

    2008-09-01

    Cryptococcus neoformans is one of the medically important yeast-like fungi. C. neoformans var. gatti has been made a species: C. gatti. In our country, there are few studies about these two species and their serotypes. The aim of this study was to determine the distribution of C. neoformans and C. gattii, and their serotypes in Venezuelan clinical isolates. One hundred and twenty C. neoformans and 12 C. gattii clinical isolates were identified by L-canavanine, glycine, and bromothymol blue agar media (CGB). These were investigated by agglutination and adsorption studies with anticryptococcal sera, which were produced by rabbit immunization. Of the 132 isolates 59.8% were typed serotype A (C. neoformans), followed by 25.8% serotype D (C. neoformans), 5.3% serotype AD (C. neoformans), and 5.3% were typed serotype C (var. gattii). Additionally 3.8% were serotype B (C. gattii).

  5. The fission yeast homologue of CENP-B, Abp1, regulates directionality of mating-type switching.

    PubMed

    Aguilar-Arnal, Lorena; Marsellach, Francesc-Xavier; Azorín, Fernando

    2008-04-09

    In fission yeast, mating-type switching involves replacing genetic information contained at the expressed mat1 locus by that of either the mat2P or mat3M donor loci. Donor selection is nonrandom, as mat1P cells preferentially use mat3M for switching, whereas mat1M cells use mat2P. Switching directionality is determined by the cell-type-specific distribution of the Swi2-Swi5 complex that, in mat1P cells, localises to mat3M and, only in mat1M cells, spreads to mat2P in a heterochromatin-dependent manner. Mechanisms regulating spreading of Swi2-Swi5 across heterochromatin are not fully understood. Here, we show that the fission yeast homologue of CENP-B, Abp1, binds to the silent domain of the mating-type locus and regulates directionality of switching. Deletion of abp1 prevents utilisation of mat2P, as when heterochromatin is disrupted and spreading of Swi2-Swi5 is impaired. Our results show that, indeed, deletion of abp1 abolishes spreading of Swi2-Swi5 to mat2P. However, in abp1Delta cells, heterochromatin organisation at the mating-type locus is preserved, indicating that Abp1 is actually required for efficient spreading of Swi2-Swi5 through heterochromatin. Cbh1 and Cbh2, which are also homologous to CENP-B, have only a minor contribution to the regulation of directionality of switching, which is in contrast with the strong effects observed for Abp1.

  6. Distribution of Suicin Gene Clusters in Streptococcus suis Serotype 2 Belonging to Sequence Types 25 and 28

    PubMed Central

    Athey, Taryn B. T.; Vaillancourt, Katy; Frenette, Michel; Gottschalk, Marcelo

    2016-01-01

    Recently, we reported the purification and characterization of three distinct lantibiotics (named suicin 90-1330, suicin 3908, and suicin 65) produced by Streptococcus suis. In this study, we investigated the distribution of the three suicin lantibiotic gene clusters among serotype 2 S. suis strains belonging to sequence type (ST) 25 and ST28, the two dominant STs identified in North America. The genomes of 102 strains were interrogated for the presence of suicin gene clusters encoding suicins 90-1330, 3908, and 65. The gene cluster encoding suicin 65 was the most prevalent and mainly found among ST25 strains. In contrast, none of the genes related to suicin 90-1330 production were identified in 51 ST25 strains nor in 35/51 ST28 strains. However, the complete suicin 90-1330 gene cluster was found in ten ST28 strains, although some genes in the cluster were truncated in three of these isolates. The vast majority (101/102) of S. suis strains did not possess any of the genes encoding suicin 3908. In conclusion, this study indicates heterogeneous distribution of suicin genes in S. suis. PMID:28078298

  7. NGSCheckMate: software for validating sample identity in next-generation sequencing studies within and across data types.

    PubMed

    Lee, Sejoon; Lee, Soohyun; Ouellette, Scott; Park, Woong-Yang; Lee, Eunjung A; Park, Peter J

    2017-03-23

    In many next-generation sequencing (NGS) studies, multiple samples or data types are profiled for each individual. An important quality control (QC) step in these studies is to ensure that datasets from the same subject are properly paired. Given the heterogeneity of data types, file types and sequencing depths in a multi-dimensional study, a robust program that provides a standardized metric for genotype comparisons would be useful. Here, we describe NGSCheckMate, a user-friendly software package for verifying sample identities from FASTQ, BAM or VCF files. This tool uses a model-based method to compare allele read fractions at known single-nucleotide polymorphisms, considering depth-dependent behavior of similarity metrics for identical and unrelated samples. Our evaluation shows that NGSCheckMate is effective for a variety of data types, including exome sequencing, whole-genome sequencing, RNA-seq, ChIP-seq, targeted sequencing and single-cell whole-genome sequencing, with a minimal requirement for sequencing depth (>0.5X). An alignment-free module can be run directly on FASTQ files for a quick initial check. We recommend using this software as a QC step in NGS studies.

  8. Assortative mating in animals.

    PubMed

    Jiang, Yuexin; Bolnick, Daniel I; Kirkpatrick, Mark

    2013-06-01

    Assortative mating occurs when there is a correlation (positive or negative) between male and female phenotypes or genotypes across mated pairs. To determine the typical strength and direction of assortative mating in animals, we carried out a meta-analysis of published measures of assortative mating for a variety of phenotypic and genotypic traits in a diverse set of animal taxa. We focused on the strength of assortment within populations, excluding reproductively isolated populations and species. We collected 1,116 published correlations between mated pairs from 254 species (360 unique species-trait combinations) in five phyla. The mean correlation between mates was 0.28, showing an overall tendency toward positive assortative mating within populations. Although 19% of the correlations were negative, simulations suggest that these could represent type I error and that negative assortative mating may be rare. We also find significant differences in the strength of assortment among major taxonomic groups and among trait categories. We discuss various possible reasons for the evolution of assortative mating and its implications for speciation.

  9. Mating types in yeast, vomeronasal organ in rodents, homosexuality in humans: does a guiding thread exist?

    PubMed

    Oliva, Daniele

    2002-08-01

    Pheromones and their receptors are the molecules used by very different organisms in order to join two haploid cells. It happens evidently in yeast, since the two blending haploid cells are also the two mating organisms, whereas in rodents pheromone receptors are the triggers of the vomeronasal system which, supervising sexual behaviors, is responsible for copulation and therefore for fertilization. The debate is still open about the real significance of pheromones in humans but a working vomeronasal organ, able to recognize pheromones of the same sex, could be the simplest biological explanation of homosexuality. This hypothesis is discussed and connected with some well known experimental data.

  10. Characterization of Chinese Haemophilus parasuis Isolates by Traditional Serotyping and Molecular Serotyping Methods

    PubMed Central

    Ma, Lina; Wang, Liyan; Chu, Yuefeng; Li, Xuerui; Cui, Yujun; Chen, Shengli; Zhou, Jianhua; Li, Chunling; Lu, Zhongxin; Liu, Jixing; Liu, Yongsheng

    2016-01-01

    Haemophilus parasuis is classified mainly through serotyping, but traditional serotyping always yields non-typable (NT) strains and unreliable results via cross-reactions. Here, we surveyed the serotype prevalence of Chinese H. parasuis isolates using traditional serotyping (gel immuno-diffusion test, GID) and molecular serotyping (multiplex PCR, mPCR). We also investigated why discrepant results between these methods were obtained, and investigated mPCR failure through whole-genome sequencing. Of the 100 isolate tested, 73 (73%) and 93 (93%) were serotyped by the GID test and mPCR, respectively, with a concordance rate of 66% (66/100). Additionally, mPCR reduced the number of NT isolates from 27 (27%) for the GID testing, to seven (7%). Eleven isolates were sequenced, including nine serotype-discrepant isolates from mPCR and GID typing (excluding strains that were NT by GID only) and two NT isolates from both methods, and their in silico serotypes were obtained from genome sequencing based on their capsule loci. The mPCR results were supported by the in silico serotyping of the seven serotype-discrepant isolates. The discrepant results and NT isolates determined by mPCR were attributed to deletions and unknown sequences in the serotype-specific region of each capsule locus. Compared with previous investigations, this study found a similar predominant serotype profile, but a different prevalence frequency for H. parasuis, and the five most prevalent serotypes or strain groups were serotypes 5, 4, NT, 7 and 13 for mPCR, and serotypes 5, NT, 4, 7 and 13/10/14 for GID. Additionally, serotype 7 was recognized as a principal serotype in this work. PMID:28005999

  11. Serotyping and multilocus sequence typing of Streptococcus pneumoniae isolates from the blood and posterior nares of Japanese children prior to the introduction of 7-valent pneumococcal conjugate vaccine.

    PubMed

    Oishi, Tomohiro; Wada, Akihito; Chang, Bin; Toyabe, Shinichi; Uchiyama, Makoto

    2011-01-01

    In Japan, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2010. To assess the effects of PCV7 on invasive pneumococcal infection in children, a population-based prospective survey has been conducted in 10 prefectures. As a part of the study, blood and nasopharyngeal isolates from children admitted to the Shibata Hospital, Niigata Prefecture, were analyzed for determining the serotypes, their susceptibilities to antimicrobial agents, and multilocus sequence types. Sixteen blood isolates were obtained from October 2007 to December 2009. Sixty-three nasopharyngeal isolates were obtained from the posterior nares of 118 children with pneumonia from April to September 2008. The coverage rates of the blood and nasopharyngeal isolates for PCV7 were 81.3% and 57.1%, respectively. Although none of these children had received PCV7, serotype 19A isolates were recovered from 12.5% (2/16) of the blood samples and 12.7% (8/63) of the nasopharyngeal samples. The sequence type of a nasopharyngeal isolate of serotype 19A was ST320, and the minimum inhibitory concentration of penicillin G was 4 μg/mL. In addition to the continuous prospective survey of pneumococcal infection, early introduction of the 13-valent conjugate vaccine, in which the 19A conjugate is included, will be necessary in Japan.

  12. Sexual reproduction and mating-type-mediated strain development in the penicillin-producing fungus Penicillium chrysogenum.

    PubMed

    Böhm, Julia; Hoff, Birgit; O'Gorman, Céline M; Wolfers, Simon; Klix, Volker; Binger, Danielle; Zadra, Ivo; Kürnsteiner, Hubert; Pöggeler, Stefanie; Dyer, Paul S; Kück, Ulrich

    2013-01-22

    Penicillium chrysogenum is a filamentous fungus of major medical and historical importance, being the original and present-day industrial source of the antibiotic penicillin. The species has been considered asexual for more than 100 y, and despite concerted efforts, it has not been possible to induce sexual reproduction, which has prevented sexual crosses being used for strain improvement. However, using knowledge of mating-type (MAT) gene organization, we now describe conditions under which a sexual cycle can be induced leading to production of meiotic ascospores. Evidence of recombination was obtained using both molecular and phenotypic markers. The identified heterothallic sexual cycle was used for strain development purposes, generating offspring with novel combinations of traits relevant to penicillin production. Furthermore, the MAT1-1-1 mating-type gene, known primarily for a role in governing sexual identity, was also found to control transcription of a wide range of genes with biotechnological relevance including those regulating penicillin production, hyphal morphology, and conidial formation. These discoveries of a sexual cycle and MAT gene function are likely to be of broad relevance for manipulation of other asexual fungi of economic importance.

  13. Characterization of two genes required for the position-effect control of yeast mating-type genes.

    PubMed Central

    Shore, D; Squire, M; Nasmyth, K A

    1984-01-01

    The mating type of haploid yeast (a or alpha) is determined by information present at the MAT locus. Identical copies of a and alpha information are present at distal loci (HMR and HML), but transcription of these copies is repressed by the action, in trans, of four unlinked genes called SIR (silent information regulator). Repression by SIR also requires, in cis, DNA sequences called E which are found to the left of HML and HMR (but not MAT) and are greater than 1 kb from the mating-type gene promoters. SIR control can act on other promoters when they are brought near the E sequence, and thus the SIR gene products act in some general manner to repress transcription. We have determined the DNA sequence of two fragments which complement mutations in the SIR2 and SIR3 genes and show that these contain the structural genes by mapping the cloned sequences onto the yeast chromosome. The SIR2 and SIR3 coding sequences were identified by constructing gene disruptions and using these mutations to replace the normal chromosomal copies. Such null mutants of both SIR2 and SIR3 are defective in the position-effect control of the silent loci but have no other detectable phenotype. We have mapped the 5' and 3' ends of the SIR2 and SIR3 mRNAs and show that their level is unaffected by mutations in any of the four known SIR complementation groups. Images Fig. 2. Fig. 3. Fig. 4. PMID:6098447

  14. Efficient production of a ring derivative of chromosome III by the mating-type switching mechanism in Saccharomyces cerevisiae.

    PubMed Central

    Klar, A J; Strathern, J N; Hicks, J B; Prudente, D

    1983-01-01

    The mating-type switches in the yeast Saccharomyces cerevisiae occur by unidirectional transposition of replicas of unexpressed genetic information, residing at HML or HMR, into the mating-type locus (MAT). The source loci, HML and HMR, remain unchanged. Interestingly, when the HM cassettes are expressed, as in marl strains, the HML and HMR cassettes can also efficiently switch, apparently by obtaining genetic information from either of the other two cassettes (Klar et al., Cell 25:517-524, 1981). We have isolated a novel chromosome III rearrangement in heterothallic (marl ho) strains, which is also produced efficiently in marl HO cells, presumably the consequence of a recombination event between HML and HMR. The fusion results in the loss of sequences which are located distal to HML and to HMR and produces a ring derivative of chromosome III. Cells containing such a ring chromosome are viable as haploids; apparently, no essential loci are located distal to the HM loci. The fusion cassette behaves as a standard HM locus with respect to both regulation by the MAR/SIR control and its role in switching MAT. Images PMID:6346056

  15. Simultaneously typing nine serotypes of enteroviruses associated with hand, foot, and mouth disease by a GeXP analyzer-based multiplex reverse transcription-PCR assay.

    PubMed

    Hu, Xiumei; Zhang, Yong; Zhou, Xiaomian; Xu, Banglao; Yang, Mengjie; Wang, Miao; Zhang, Chen; Li, Jin; Bai, Ruyin; Xu, Wenbo; Ma, Xuejun

    2012-02-01

    Hand, foot, and mouth disease (HFMD) is a contagious enteroviral disease occurring primarily in young children and caused by enterovirus 71 (EV71), coxsackievirus A16 (CVA16), and other serotypes of coxsackievirus and echovirus. In this study, a GeXP analyzer-based multiplex reverse transcription (RT)-PCR assay (GeXP assay) consisting of chimeric primer-based PCR amplification with fluorescent labeling and capillary electrophoresis separation was developed to simultaneously identify nine serotypes of enteroviruses associated with HFMD in China, including EV71, CVA16, CVA4, -5, -9, and -10, and CVB1, -3, and -5. The RNAs extracted from cell cultures of viral isolates and synthetic RNAs via in vitro transcription were used to analyze the specificity and sensitivity of the assay. The GeXP assay detected as little as 0.03 tissue culture infective dose (TCID(50)) of EV71 and CVA16, 10 copies of panenterovirus, EV71, CVA16, CVB1, and CVB5, and 100 copies of 10 (including panenterovirus) premixed RNA templates. A total of 180 stool specimens collected from HFMD patients and persons suspected of having HFMD were used to evaluate the clinical performance of this assay. In comparison with the results of conventional methods, the sensitivities of the GeXP assay for detection of panenterovirus, EV71, and CVA16 were 98.79% (163/165), 91.67% (44/48), and 91.67% (33/36), respectively, and the specificities were 80.00% (12/15), 98.48% (130/132), and 100% (144/144), respectively. The concordance of typing seven other serotypes of enteroviruses with the results of conventional methods was 92.59% (25/27). In conclusion, the GeXP assay is a rapid, cost-effective, and high-throughput method for typing nine serotypes of HFMD-associated enteroviruses.

  16. Association of type- and group-specific antigens with the cell wall of serotype III group B streptococcus.

    PubMed Central

    Doran, T I; Mattingly, S J

    1982-01-01

    The type-specific antigens (TSA) of group B streptococcus (GBS) represent the primary virulence factors for these organisms, yet little is known about their relationship to the cell surface of GBS. Crude cell walls of serotype III GBS strain 110 were purified by extraction with sodium dodecyl sulfate, LiCl, and urea, which removed essentially all of the protein associated with the cell wall as determined by amino acid analysis. Only those amino acids found in peptidoglycan were present, which included alanine, lysine, and glutamate (3.5:1:1 molar ratio). In contrast, these procedures resulted in the release of only 4.6% of the wall-associated TSA, indicating that protein was not the primary means by which TSA was bound to the cell surface. Mutanolysin (20 micrograms/ml) treatment of purified cell walls resulted in the release of 95% of the wall-associated TSA. The covalent association of TSA, the group B polysaccharide, and the peptidoglycan was demonstrated by the presence of N-acetylmuramic acid, rhamnose, alanine, glutamate, and lysine in mutanolysin-extracted TSA material purified by DEAE-Sephacel anion exchange and Sepharose 4B gel chromatography. Chemical analysis of purified cell walls revealed that group B antigen and peptidoglycan comprised 37.4 and 36.5%, respectively, whereas TSA accounted for 22.1 to 24.5% of the weight of the purified walls. Of the total 283.5 mg of TSA produced per 10-liter culture of GBS strain 110, 8.4% was released into the supernatant fluid. The remainder (249 mg) comprised the cell wall antigen. As described above, 4.6% of the cell wall antigen was extractable by nonenzymatic methods, which represented 3.8% of the total TSA, whereas 87.8% of the total TSA produced appeared to be covalently attached to the cell wall. PMID:7047392

  17. Typing and characterization of ColE1-like plasmids conferring kanamycin resistance in Salmonella enterica serotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Multi-antibiotic resistant Salmonella enterica serotypes are increasing in prevalence and concern in human and animal health. Many strains carry resistance determinants on plasmids; current practices focus heavily on large plasmids and the role small plasmids play in resistance gene tra...

  18. The mating type-specific homeodomain genes SXI1 alpha and SXI2a coordinately control uniparental mitochondrial inheritance in Cryptococcus neoformans.

    PubMed

    Yan, Zhun; Hull, Christina M; Sun, Sheng; Heitman, Joseph; Xu, Jianping

    2007-03-01

    In the great majority of sexual eukaryotes, mitochondrial genomes are inherited almost exclusively from a single parent. While many hypotheses have been proposed to explain this phenomenon, very little is known about the genetic elements controlling uniparental mitochondria inheritance. In the bipolar, isogamous basidiomycete yeast Cryptococcus neoformans, progeny from crosses between strains of mating type a (MATa) and mating type alpha (MATalpha) typically inherit mitochondrial DNA (mtDNA) from the MATa parent. We recently demonstrated that a mating type alpha (MATalpha)-specific gene SXI1a, controls mitochondrial inheritance in C. neoformans. Here, we show that another homeodomain gene SXI2a in the alternative mating type MATa is also required for uniparental mtDNA inheritance in this fungus. Disruption of SXI2a resulted in biparental mtDNA inheritance in the zygote population with significant numbers of progeny inheriting mtDNA from the MATa parent, the MATalpha parent, and both the MATa and the MATalpha parents. In addition, progeny from same-sex mating between MATalpha strains showed a biparental mitochondrial inheritance pattern. Our results suggest that SXI1alpha and SXI2a coordinately control uniparental mitochondrial inheritance in C. neoformans.

  19. Antiviral activity of Basidiomycete mycelia against influenza type A (serotype H1N1) and herpes simplex virus type 2 in cell culture.

    PubMed

    Krupodorova, Tetiana; Rybalko, Svetlana; Barshteyn, Victor

    2014-10-01

    In this study, we investigated the in vitro antiviral activity of the mycelia of higher mushrooms against influenza virus type A (serotype H1N1) and herpes simplex virus type 2 (HSV-2), strain BH. All 10 investigated mushroom species inhibited the reproduction of influenza virus strain A/FM/1/47 (H1N1) in MDCK cells reducing the infectious titer by 2.0-6.0 lg ID50. Four species, Pleurotus ostreatus, Fomes fomentarius, Auriporia aurea, and Trametes versicolor, were also determined to be effective against HSV-2 strain BH in RK-13 cells, with similar levels of inhibition as for influenza. For some of the investigated mushroom species-Pleurotus eryngii, Lyophyllum shimeji, and Flammulina velutipes-this is the first report of an anti-influenza effect. This study also reports the first data on the medicinal properties of A. aurea, including anti-influenza and antiherpetic activities. T. versicolor 353 mycelium was found to have a high therapeutic index (324.67), and may be a promising material for the pharmaceutical industry as an anti-influenza and antiherpetic agent with low toxicity. Mycelia with antiviral activity were obtained in our investigation by bioconversion of agricultural wastes (amaranth flour after CO2 extraction), which would reduce the cost of the final product and solve some ecological problems.

  20. αADα Hybrids of Cryptococcus neoformans: Evidence of Same-Sex Mating in Nature and Hybrid Fitness

    PubMed Central

    Lin, Xiaorong; Litvintseva, Anastasia P; Nielsen, Kirsten; Patel, Sweta; Floyd, Anna; Mitchell, Thomas G; Heitman, Joseph

    2007-01-01

    Cryptococcus neoformans is a ubiquitous human fungal pathogen that causes meningoencephalitis in predominantly immunocompromised hosts. The fungus is typically haploid, and sexual reproduction involves two individuals with opposite mating types/sexes, α and a. However, the overwhelming predominance of mating type (MAT) α over a in C. neoformans populations limits α–a mating in nature. Recently it was discovered that C. neoformans can undergo same-sex mating under laboratory conditions, especially between α isolates. Whether same-sex mating occurs in nature and contributes to the current population structure was unknown. In this study, natural αADα hybrids that arose by fusion between two α cells of different serotypes (A and D) were identified and characterized, providing definitive evidence that same-sex mating occurs naturally. A novel truncated allele of the mating-type-specific cell identity determinant SXI1α was also identified as a genetic factor likely involved in this process. In addition, laboratory-constructed αADα strains exhibited hybrid vigor both in vitro and in vivo, providing a plausible explanation for their relative abundance in nature despite the fact that AD hybrids are inefficient in meiosis/sporulation and are trapped in the diploid state. These findings provide insights on the origins, genetic mechanisms, and fitness impact of unisexual hybridization in the Cryptococcus population. PMID:17953489

  1. Mating system, feeding type and ex situ conservation effort determine life expectancy in captive ruminants.

    PubMed

    Müller, Dennis W H; Lackey, Laurie Bingaman; Streich, W Jürgen; Fickel, Jörns; Hatt, Jean-Michel; Clauss, Marcus

    2011-07-07

    Zoo animal husbandry aims at constantly improving husbandry, reproductive success and ultimately animal welfare. Nevertheless, analyses to determine factors influencing husbandry of different species are rare. The relative life expectancy (rLE; life expectancy (LE) as proportion of longevity) describes husbandry success of captive populations. Correlating rLE with biological characteristics of different species, reasons for variation in rLE can be detected. We analysed data of 166 901 animals representing 78 ruminant species kept in 850 facilities. The rLE of females correlated with the percentage of grass in a species' natural diet, suggesting that needs of species adapted to grass can be more easily accommodated than the needs of those adapted to browse. Males of monogamous species demonstrate higher rLE than polygamous males, which matches observed differences of sexual bias in LE in free-living populations and thus supports the ecological theory that the mating system influences LE. The third interesting finding was that rLE was higher in species managed by international studbooks when compared with species not managed in this way. Our method facilitates the identification of biological characteristics of species that are relevant for their husbandry success, and they also support ecological theory. Translating these findings into feeding recommendations, our approach can help to improve animal husbandry.

  2. Mating in parents of type 1 diabetes families as a function of the HLA DR-DQ haplotype

    PubMed Central

    Kahles, H.; Kordonouri, O.; Ramos Lopez, E.; Walter, M.; Rosinger, S.; Boehm, B. O.; Badenhoop, K.; Seidl, C.; Ziegler, A.

    2009-01-01

    Aim The Major Histocompatibility Complex (MHC) region on chromosome 6p21 (IDDM1) contributes about half of the familial clustering of type 1 diabetes (T1D). Several studies have revealed that highly polymorphic genes within the MHC may associate with the mating choice. Our study should determine whether a specific mating effect is detectable in T1D families as a function of human leucocyte antigen (HLA) DR-DQ, which could contribute to disease susceptibility. Methods We analysed the parental HLA-DR genotypes in 829 diabetic families. The families derive from the Type 1 Diabetes Genetics Consortium (T1DGC) in addition to those of our own centre and the original UK, US and SCAND diabetic families. Results A total of 307 of 829 parental couples (37.0%) were matched for at least one known T1D risk haplotype (DR3 or DR4), which is significantly less than the expected 374.9 (45.2%), derived from population genotype frequencies (p < 0.0009). Parents share less susceptibility haplotypes and rather complement each other as both carry one different risk haplotype (DR3 or DR4). The number of such parental couples was significantly higher than expected (293 vs. 223.4; p < 0.0003). All non-transmitted DR haplotype pairs were also analysed. More often than expected, both parents did not transmit DR1 (94 vs. 59.1; p < 0.003) and DRy (y: not DR1, not DR3, not DR4; 63 vs. 30.3; p < 0.0005). In contrast, the parental non-transmitted pair of haplotypes DR1-DRy was observed to a far lesser extent than expected (26 vs. 84.7; p < 10−8). These observations were only made in multiplex families, whereas in simplex families, no deviation from the expected frequencies was observed. Conclusions Our data are consistent with the conclusion that genes in the HLA region may influence the mating choice in parents of T1D patients, thus contributing to familial clustering of T1D in multiplex families. This may indicate a different parental background of multiplex compared with simplex T1D families

  3. Unequal Recombination and Evolution of the Mating-Type (MAT) Loci in the Pathogenic Fungus Grosmannia clavigera and Relatives

    PubMed Central

    Tsui, Clement K.-M.; DiGuistini, Scott; Wang, Ye; Feau, Nicolas; Dhillon, Braham; Bohlmann, Jörg; Hamelin, Richard C.

    2013-01-01

    Sexual reproduction in fungi is regulated by the mating-type (MAT) locus where recombination is suppressed. We investigated the evolution of MAT loci in eight fungal species belonging to Grosmannia and Ophiostoma (Sordariomycetes, Ascomycota) that include conifer pathogens and beetle symbionts. The MAT1-2 idiomorph/allele was identified from the assembled and annotated Grosmannia clavigera genome, and the MAT locus is flanked by genes coding for cytoskeleton protein (SLA) and DNA lyase. The synteny of these genes is conserved and consistent with other members in Ascomycota. Using sequences from SLA and flanking regions, we characterized the MAT1-1 idiomorph from other isolates of G. clavigera and performed dotplot analysis between the two idiomorphs. Unexpectedly, the MAT1-2 idiomorph contains a truncated MAT1-1-1 gene upstream of the MAT1-2-1 gene that bears the high-mobility-group domain. The nucleotide and amino acid sequence of the truncated MAT1-1-1 gene is similar to its homologous copy in the MAT1-1 idiomorph in the opposite mating-type isolate, except that positive selection is acting on the truncated gene and the alpha(α)-box that encodes the transcription factor has been deleted. The MAT idiomorphs sharing identical gene organization were present in seven additional species in the Ophiostomatales, suggesting that the presence of truncated MAT1-1-1 gene is a general pattern in this order. We propose that an ancient unequal recombination event resulted in the ancestral MAT1-1-1 gene integrated into the MAT1-2 idiomorph and surviving as the truncated MAT1-1-1 genes. The α-box domain of MAT1-1-1 gene, located at the same MAT locus adjacent to the MAT1-2-1 gene, could have been removed by deletion after recombination due to mating signal interference. Our data confirmed a 1:1 MAT/sex ratio in two pathogen populations, and showed that all members of the Ophiostomatales studied here including those that were previously deemed asexual have the potential to

  4. Transcription of novel genes, including a gene linked to the mating-type locus, induced by Chlamydomonas fertilization.

    PubMed Central

    Ferris, P J; Goodenough, U W

    1987-01-01

    Six cDNA clones have been identified that are complementary to transcripts present in young zygotes of Chlamydomonas reinhardtii but absent from vegetative and gametic cells. Five early transcripts are synthesized within 5 to 10 min of fertilization; the sixth, late, transcript is not synthesized until 90 min following fertilization. Synthesis of both classes requires cell fusion between gametes. Cycloheximide fails to inhibit early mRNA synthesis, indicating that transcription factors must preexist in the gametes and be activated by cytoplasmic confluence. By contrast, cycloheximide blocks synthesis of the late transcript, suggesting that an early protein product(s) is required for expression of the late gene. Restriction fragment length polymorphism analysis of inter- and intraspecific genetic crosses demonstrates that one of the early genes is very tightly linked to the mating-type locus. Images PMID:3614194

  5. A New Quaternary Structure Epitope on Dengue Virus Serotype 2 Is the Target of Durable Type-Specific Neutralizing Antibodies

    PubMed Central

    Gallichotte, E. N.; Widman, D. G.; Yount, B. L.; Wahala, W. M.; Durbin, A.; Whitehead, S.; Sariol, C. A.; Crowe, J. E.

    2015-01-01

    ABSTRACT Dengue virus serotype 2 (DENV2) is widespread and responsible for severe epidemics. While primary DENV2 infections stimulate serotype-specific protective responses, a leading vaccine failed to induce a similar protective response. Using human monoclonal antibodies (hMAbs) isolated from dengue cases and structure-guided design of a chimeric DENV, here we describe the major site on the DENV2 envelope (E) protein targeted by neutralizing antibodies. DENV2-specific neutralizing hMAb 2D22 binds to a quaternary structure epitope. We engineered and recovered a recombinant DENV4 that displayed the 2D22 epitope. DENV2 neutralizing antibodies in people exposed to infection or a live vaccine tracked with the 2D22 epitope on the DENV4/2 chimera. The chimera remained sensitive to DENV4 antibodies, indicating that the major neutralizing epitopes on DENV2 and -4 are at different sites. The ability to transplant a complex epitope between DENV serotypes demonstrates a hitherto underappreciated structural flexibility in flaviviruses, which could be harnessed to develop new vaccines and diagnostics. PMID:26463165

  6. Neutralization serotypes of human immunodeficiency virus type 1 field isolates are not predicted by genetic subtype. The WHO Network for HIV Isolation and Characterization.

    PubMed Central

    Weber, J; Fenyö, E M; Beddows, S; Kaleebu, P; Björndal, A

    1996-01-01

    Human immunodeficiency virus type 1 (HIV-1) primary isolates from four geographical locations in Thailand, Brazil, Rwanda, and Uganda, representing genetic subtypes A, B, C, D, and E, were examined for autologous and heterologous neutralization by panels of human HIV+ polyclonal plasma. In independent linked experiments in three laboratories using diverse methodologies and common reagents, no defined pattern of genetic subtype-specific neutralization was observed. Most plasma tested were broadly cross-neutralizing across two or more genetic subtypes, although the titer of neutralization varied across a wide range. We conclude that the genetic subtypes of HIV-1 are not classical neutralization serotypes. PMID:8892904

  7. Analysis of Clostridium botulinum Serotype E Strains by Using Multilocus Sequence Typing, Amplified Fragment Length Polymorphism, Variable-Number Tandem-Repeat Analysis, and Botulinum Neurotoxin Gene Sequencing▿

    PubMed Central

    Macdonald, Thomas E.; Helma, Charles H.; Shou, Yulin; Valdez, Yolanda E.; Ticknor, Lawrence O.; Foley, Brian T.; Davis, Stephen W.; Hannett, George E.; Kelly-Cirino, Cassandra D.; Barash, Jason R.; Arnon, Stephen S.; Lindström, Miia; Korkeala, Hannu; Smith, Leonard A.; Smith, Theresa J.; Hill, Karen K.

    2011-01-01

    A total of 41 Clostridium botulinum serotype E strains from different geographic regions, including Canada, Denmark, Finland, France, Greenland, Japan, and the United States, were compared by multilocus sequence typing (MLST), amplified fragment length polymorphism (AFLP) analysis, variable-number tandem-repeat (VNTR) analysis, and botulinum neurotoxin (bont) E gene sequencing. The strains, representing environmental, food-borne, and infant botulism samples collected from 1932 to 2007, were analyzed to compare serotype E strains from different geographic regions and types of botulism and to determine whether each of the strains contained the transposon-associated recombinase rarA, involved with bont/E insertion. MLST examination using 15 genes clustered the strains into several clades, with most members within a cluster sharing the same BoNT/E subtype (BoNT/E1, E2, E3, or E6). Sequencing of the bont/E gene identified two new variants (E7, E8) that showed regions of recombination with other E subtypes. The AFLP dendrogram clustered the 41 strains similarly to the MLST dendrogram. Strains that could not be differentiated by AFLP, MLST, or bont gene sequencing were further examined using three VNTR regions. Both intact and split rarA genes were amplified by PCR in each of the strains, and their identities were confirmed in 11 strains by amplicon sequencing. The findings suggest that (i) the C. botulinum serotype E strains result from the targeted insertion of the bont/E gene into genetically conserved bacteria and (ii) recombination events (not random mutations) within bont/E result in toxin variants or subtypes within strains. PMID:22003031

  8. MLST and Whole-Genome-Based Population Analysis of Cryptococcus gattii VGIII Links Clinical, Veterinary and Environmental Strains, and Reveals Divergent Serotype Specific Sub-populations and Distant Ancestors

    PubMed Central

    Firacative, Carolina; Roe, Chandler C.; Malik, Richard; Ferreira-Paim, Kennio; Escandón, Patricia; Sykes, Jane E.; Castañón-Olivares, Laura Rocío; Contreras-Peres, Cudberto; Samayoa, Blanca; Sorrell, Tania C.; Castañeda, Elizabeth; Lockhart, Shawn R.; Engelthaler, David M.; Meyer, Wieland

    2016-01-01

    The emerging pathogen Cryptococcus gattii causes life-threatening disease in immunocompetent and immunocompromised hosts. Of the four major molecular types (VGI-VGIV), the molecular type VGIII has recently emerged as cause of disease in otherwise healthy individuals, prompting a need to investigate its population genetic structure to understand if there are potential genotype-dependent characteristics in its epidemiology, environmental niche(s), host range and clinical features of disease. Multilocus sequence typing (MLST) of 122 clinical, environmental and veterinary C. gattii VGIII isolates from Australia, Colombia, Guatemala, Mexico, New Zealand, Paraguay, USA and Venezuela, and whole genome sequencing (WGS) of 60 isolates representing all established MLST types identified four divergent sub-populations. The majority of the isolates belong to two main clades, corresponding either to serotype B or C, indicating an ongoing species evolution. Both major clades included clinical, environmental and veterinary isolates. The C. gattii VGIII population was genetically highly diverse, with minor differences between countries, isolation source, serotype and mating type. Little to no recombination was found between the two major groups, serotype B and C, at the whole and mitochondrial genome level. C. gattii VGIII is widespread in the Americas, with sporadic cases occurring elsewhere, WGS revealed Mexico and USA as a likely origin of the serotype B VGIII population and Colombia as a possible origin of the serotype C VGIII population. Serotype B isolates are more virulent than serotype C isolates in a murine model of infection, causing predominantly pulmonary cryptococcosis. No specific link between genotype and virulence was observed. Antifungal susceptibility testing against six antifungal drugs revealed that serotype B isolates are more susceptible to azoles than serotype C isolates, highlighting the importance of strain typing to guide effective treatment to improve the

  9. MLST and Whole-Genome-Based Population Analysis of Cryptococcus gattii VGIII Links Clinical, Veterinary and Environmental Strains, and Reveals Divergent Serotype Specific Sub-populations and Distant Ancestors.

    PubMed

    Firacative, Carolina; Roe, Chandler C; Malik, Richard; Ferreira-Paim, Kennio; Escandón, Patricia; Sykes, Jane E; Castañón-Olivares, Laura Rocío; Contreras-Peres, Cudberto; Samayoa, Blanca; Sorrell, Tania C; Castañeda, Elizabeth; Lockhart, Shawn R; Engelthaler, David M; Meyer, Wieland

    2016-08-01

    The emerging pathogen Cryptococcus gattii causes life-threatening disease in immunocompetent and immunocompromised hosts. Of the four major molecular types (VGI-VGIV), the molecular type VGIII has recently emerged as cause of disease in otherwise healthy individuals, prompting a need to investigate its population genetic structure to understand if there are potential genotype-dependent characteristics in its epidemiology, environmental niche(s), host range and clinical features of disease. Multilocus sequence typing (MLST) of 122 clinical, environmental and veterinary C. gattii VGIII isolates from Australia, Colombia, Guatemala, Mexico, New Zealand, Paraguay, USA and Venezuela, and whole genome sequencing (WGS) of 60 isolates representing all established MLST types identified four divergent sub-populations. The majority of the isolates belong to two main clades, corresponding either to serotype B or C, indicating an ongoing species evolution. Both major clades included clinical, environmental and veterinary isolates. The C. gattii VGIII population was genetically highly diverse, with minor differences between countries, isolation source, serotype and mating type. Little to no recombination was found between the two major groups, serotype B and C, at the whole and mitochondrial genome level. C. gattii VGIII is widespread in the Americas, with sporadic cases occurring elsewhere, WGS revealed Mexico and USA as a likely origin of the serotype B VGIII population and Colombia as a possible origin of the serotype C VGIII population. Serotype B isolates are more virulent than serotype C isolates in a murine model of infection, causing predominantly pulmonary cryptococcosis. No specific link between genotype and virulence was observed. Antifungal susceptibility testing against six antifungal drugs revealed that serotype B isolates are more susceptible to azoles than serotype C isolates, highlighting the importance of strain typing to guide effective treatment to improve the

  10. Improved detection of nasopharyngeal cocolonization by multiple pneumococcal serotypes by use of latex agglutination or molecular serotyping by microarray.

    PubMed

    Turner, Paul; Hinds, Jason; Turner, Claudia; Jankhot, Auscharee; Gould, Katherine; Bentley, Stephen D; Nosten, François; Goldblatt, David

    2011-05-01

    Identification of Streptococcus pneumoniae in the nasopharynx is critical for an understanding of transmission, estimates of vaccine efficacy, and possible replacement disease. Conventional nasopharyngeal swab (NPS) culture and serotyping (the WHO protocol) is likely to underestimate multiple-serotype carriage. We compared the WHO protocol with methods aimed at improving cocolonization detection. One hundred twenty-five NPSs from an infant pneumococcal-carriage study, containing ≥ 1 serotype by WHO culture, were recultured in duplicate. A sweep of colonies from one plate culture was serotyped by latex agglutination. DNA extracted from the second plate was analyzed by S. pneumoniae molecular-serotyping microarray. Multiple serotypes were detected in 11.2% of the swabs by WHO culture, 43.2% by sweep serotyping, and 48.8% by microarray. Sweep and microarray were more likely to detect multiple serotypes than WHO culture (P < 0.0001). Cocolonization detection rates were similar between microarray and sweep, but the microarray identified the greatest number of serotypes. A common serogroup type was identified in 95.2% of swabs by all methods. WHO methodology significantly underestimates multiple-serotype carriage compared to these alternate methods. Sweep serotyping is cost-effective and field deployable but may fail to detect serotypes at low abundance, whereas microarray serotyping is more costly and technology dependent but may detect these additional minor carried serotypes.

  11. Novel Rotavirus VP7 Typing Assay Using a One-Step Reverse Transcriptase PCR Protocol and Product Sequencing and Utility of the Assay for Epidemiological Studies and Strain Characterization, Including Serotype Subgroup Analysis

    PubMed Central

    DiStefano, Daniel J.; Kraiouchkine, Nikolai; Mallette, Laura; Maliga, Marianne; Kulnis, Gregory; Keller, Paul M.; Clark, H. Fred; Shaw, Alan R.

    2005-01-01

    Rotavirus is the most common cause of severe dehydrating gastroenteritis in infants. To date, 10 different serotypes of rotavirus have been identified in human stools. While four or five serotypes dominate, serotype circulation varies with season and geography. Since our laboratory has been involved in the development of a multivalent rotavirus vaccine, it is important to identify the serotypes of rotavirus encountered during our clinical trials. We have developed methodologies for the molecular identification of rotavirus strains based on VP7 gene segment sequence. A 365-bp reverse transcriptase PCR product was generated from the VP7 gene segment using a pair of novel degenerate primers. All serotypes tested (both animal and human) yielded an identically sized product after amplification. Sequencing of these products is performed using truncated versions of the original primers. The sequence generated is compared against a database of rotavirus VP7 sequences, with the G type determined, based on the sequence homology. Using this assay, we have correctly identified human VP7 strains from a panel of available serotypes, as well as numerous animal strains. The assay was qualified using rotavirus positive stool samples, negative stool samples, and rotavirus-spiked stool samples. In addition, samples from cases of acute gastroenteritis collected at Children's Hospital of Philadelphia have been evaluated and indicate that the assay is able to discriminate subtle differences within serotypes. The assay has been utilized in the testing of >3,000 antigen-positive (enzyme immunoassay) samples collected during clinical trials of a rotavirus vaccine (RotaTeq) and identified a serotype in ∼92% of samples (3, 17, 19). PMID:16333070

  12. Peptidal Sex Hormones Inducing Conjugation Tube Formation in Compatible Mating-Type Cells of Tremella mesenterica.

    PubMed

    Sakagami, Y; Yoshida, M; Isogai, A; Suzuki, A

    1981-06-26

    The pair of peptidal sex hormones (tremerogen A-10 and tremerogen a-13) that induce conjugation tube formation in compatible type cells (A and a types) of Tremella mesenterica were isolated. Tremerogen A-10 is a dodecapeptide and tremerogen a-13, a tridecapeptide. In both peptides, the sulfiydryl group of the cysteines at the carboxyl terminus was blocked by farnesyl moieties.

  13. A serotype-specific polymerase chain reaction for identification of Pasteurella multocida serotype 1

    USGS Publications Warehouse

    Rocke, Tonie E.; Smith, Susan R.; Miyamoto, Amy; Shadduck, Daniel J.

    2002-01-01

    A serotype-specific polymerase chain reaction (PCR) assay was developed for detection and identification of Pasteurella multocida serotype 1, the causative agent of avian cholera in wild waterfowl. Arbitrarily primed PCR was used to detect DNA fragments that distinguish serotype 1 from the other 15 serotypes of P. multocida (with the exception of serotype 14). Oligonucleotide primers were constructed from these sequences, and a PCR assay was optimized and evaluated. PCR reactions consistently resulted in amplification products with reference strains 1 and 14 and all other serotype 1 strains tested, with cell numbers as low as 2.3 cells/ml. No amplification products were produced with other P. multocida serotypes or any other bacterial species tested. To compare the sensitivity and further test the specificity of this PCR assay with traditional culturing and serotyping techniques, tissue samples from 84 Pekin ducks inoculated with field strains of P. multocida and 54 wild lesser snow geese collected during an avian cholera outbreak were provided by other investigators working on avian cholera. PCR was as sensitive (58/64) as routine isolation (52/64) in detecting and identifying P. multocida serotype 1 from the livers of inoculated Pekins that became sick or died from avian cholera. No product was amplified from tissues of 20 other Pekin ducks that received serotypes other than type 1 (serotype 3, 12 × 3, or 10) or 12 control birds. Of the 54 snow geese necropsied and tested for P. multocida, our PCR detected and identified the bacteria from 44 compared with 45 by direct isolation. The serotype-specific PCR we developed was much faster and less labor intensive than traditional culturing and serotyping procedures and could result in diagnosis of serotype 1 pasteurellosis within 24 hr of specimen submission.

  14. A phase I trial of adeno-associated virus serotype 1-γ-sarcoglycan gene therapy for limb girdle muscular dystrophy type 2C.

    PubMed

    Herson, Serge; Hentati, Faycal; Rigolet, Aude; Behin, Anthony; Romero, Norma B; Leturcq, France; Laforêt, Pascal; Maisonobe, Thierry; Amouri, Rim; Haddad, Hafedh; Audit, Muriel; Montus, Marie; Masurier, Carole; Gjata, Bernard; Georger, Christophe; Cheraï, Mustapha; Carlier, Pierre; Hogrel, Jean-Yves; Herson, Ariane; Allenbach, Yves; Lemoine, François M; Klatzmann, David; Sweeney, H Lee; Mulligan, Richard C; Eymard, Bruno; Caizergues, Didier; Voït, Thomas; Benveniste, Olivier

    2012-02-01

    γ-Sarcoglycanopathy or limb girdle muscular dystrophy type 2C is an untreatable disease caused by autosomal recessively inherited mutations of the γ-sarcoglycan gene. Nine non-ambulatory patients (two males, seven females, mean age 27 years; range 16-38 years) with del525T homozygous mutation of the γ-sarcoglycan gene and no γ-sarcoglycan immunostaining on muscle biopsy were divided into three equal groups to receive three escalating doses of an adeno-associated virus serotype 1 vector expressing the human γ-sarcoglycan gene under the control of the desmin promoter, by local injection into the extensor carpi radialis muscle. The first group received a single injection of 3 × 10(9) viral genomes in 100 µl, the second group received a single injection of 1.5 × 10(10) viral genomes in 100 µl, and the third group received three simultaneous 100-µl injections at the same site, delivering a total dose of 4.5 × 10(10) viral genomes. No serious adverse effects occurred during 6 months of follow-up. All nine patients became adeno-associated virus serotype 1 seropositive and one developed a cytotoxic response to the adeno-associated virus serotype 1 capsid. Thirty days later, immunohistochemical analysis of injected-muscle biopsy specimens showed γ-sarcoglycan expression in all three patients who received the highest dose (4.7-10.5% positively stained fibres), while real-time polymerase chain reaction detected γ-sarcoglycan messenger RNA. In one patient, γ-sarcoglycan protein was detected by western blot. For two other patients who received the low and intermediate doses, discrete levels of γ-sarcoglycan expression (<1% positively stained fibres) were also detectable. Expression of γ-sarcoglycan protein can be induced in patients with limb girdle muscular dystrophy type 2C by adeno-associated virus serotype 1 gene transfer, with no serious adverse effects.

  15. Adenovirus serotype 35 vector-induced innate immune responses in dendritic cells derived from wild-type and human CD46-transgenic mice: Comparison with a fiber-substituted Ad vector containing fiber proteins of Ad serotype 35.

    PubMed

    Sakurai, Fuminori; Nakashima, Kazuko; Yamaguchi, Tomoko; Ichinose, Takako; Kawabata, Kenji; Hayakawa, Takao; Mizuguchi, Hiroyuki

    2010-12-01

    Recently, much attention has focused on replication-incompetent adenovirus (Ad) vectors containing fiber proteins derived from species B Ad serotype 35 (Ad35) (Ad5F35) and Ad vectors fully constructed from Ad35 as vaccine vectors expressing antigens. However, differences in the transduction properties, including the induction of innate immunity, of Ad5F35 and Ad35 vectors have not been properly and fully examined, partly because the transduction properties of these Ad vectors should be evaluated using nonhuman primates or human CD46-transgenic (CD46TG) mice, which ubiquitously express the primary receptor of Ad35, human CD46, in a pattern similar to that of humans. In the present study, we evaluated innate immune responses of mouse dendritic cells (mDCs) derived from bone marrow cells of wild-type (WT) and CD46TG mice following transduction with Ad serotype 5 (Ad5), fiber-substituted Ad5F35, or Ad35 vectors. Ad5F35 and Ad35 vectors mediated more efficient transduction in mDCs derived from CD46TG mice (CD46TG-mDCs) than did Ad5 vectors. Upregulation of costimulatory molecules and inflammatory cytokine induction by Ad5F35 and Ad35 vectors were significantly higher than those by Ad5 vectors in CD46TG-mDCs. However, the induction properties of the innate immune responses were different between Ad5F35 and Ad35 vectors. Ad35 vectors induced higher levels of costimulatory molecule expression and inflammatory cytokine production than did Ad5F35 vectors in CD46TG-mDCs. Furthermore, intravenous administration of Ad35 vectors in WT and CD46TG mice resulted in higher levels of serum interleukin (IL)-6 and IL-12 compared with administration of Ad5F35 vectors, which exhibited almost mock-transduced levels of these inflammatory cytokines. This study indicates that innate immune responses by Ad35 and Ad5F35 vectors are distinct even although both Ad vectors recognize human CD46 as a receptor.

  16. Cryptococcus neoformans STE12α Regulates Virulence but Is Not Essential for Mating

    PubMed Central

    Chang, Y.C.; Wickes, B.L.; Miller, G.F.; Penoyer, L.A.; Kwon-Chung, K.J.

    2000-01-01

    The Cryptococcus neoformans STE12α gene, a homologue of Saccharomyces cerevisiae STE12, exists only in mating type (MAT)α cells. In S. cerevisiae, STE12 was required for mating and filament formation. In C. neoformans, haploid fruiting on filament agar required STE12α. The ability to form hyphae, however, was not affected by deletion of STE12α when convergently growing MATa strains were present. Furthermore, ste12α disruptants were fertile when mated with MATa strains, albeit with reduced mating frequency. Most importantly, the virulence of a ste12α disruptant of serotype D strain was significantly reduced in a mouse model. When the ste12α locus was reconstituted with the wild-type allele by cotransformation, virulence was restored. Histopathological analysis demonstrated a reduction in capsular size of yeast cells, less severe cystic lesions, and stronger immune responses in meninges of mice infected with ste12α cells than those of mice infected with STE12α cells. Using reporter gene constructs, we found that STE12α controls the expression of several phenotypes known to be involved in virulence, such as capsule and melanin production. These results demonstrate a clear molecular link between mating type and virulence in C. neoformans. PMID:10704467

  17. Co-expression of the mating-type genes involved in internuclear recognition is lethal in Podospora anserina.

    PubMed Central

    Coppin, E; Debuchy, R

    2000-01-01

    In the heterothallic filamentous fungus Podospora anserina, four mating-type genes encoding transcriptional factors have been characterized: FPR1 in the mat+ sequence and FMR1, SMR1, and SMR2 in the alternative mat- sequence. Fertilization is controlled by FPR1 and FMR1. After fertilization, male and female nuclei, which have divided in the same cell, form mat+/mat- pairs during migration into the ascogenous hyphae. Previous data indicate that the formation of mat+/mat- pairs is controlled by FPR1, FMR1, and SMR2. SMR1 was postulated to be necessary for initial development of ascogenous hyphae. In this study, we investigated the transcriptional control of the mat genes by seeking mat transcripts during the vegetative and sexual phase and fusing their promoter to a reporter gene. The data indicate that FMR1 and FPR1 are expressed in both mycelia and perithecia, whereas SMR1 and SMR2 are transcribed in perithecia. Increased or induced vegetative expression of the four mat genes has no effect when the recombined gene is solely in the wild-type strain. However, the combination of resident FPR1 with deregulated SMR2 and overexpressed FMR1 in the same nucleus is lethal. This lethality is suppressed by the expression of SMR1, confirming that SMR1 operates downstream of the other mat genes. PMID:10835389

  18. Only one of the two type VI secretion systems encoded in the Salmonella enterica serotype Dublin genome is involved in colonization of the avian and murine hosts.

    PubMed

    Pezoa, David; Blondel, Carlos J; Silva, Cecilia A; Yang, Hee-Jeong; Andrews-Polymenis, Helene; Santiviago, Carlos A; Contreras, Inés

    2014-01-09

    The type VI secretion system (T6SS) is a virulence factor for many Gram-negative bacteria. Salmonella genus harbors five phylogenetically distinct T6SS loci encoded in Salmonella Pathogenicity Islands (SPIs) SPI-6, SPI-19, SPI-20, SPI-21 and SPI-22, which are differentially distributed among serotypes. The T6SSs encoded in SPI-6 and SPI-19 contribute to pathogenesis of serotypes Typhimurium and Gallinarum in mice and chickens, respectively. Salmonella Dublin is a pathogen restricted to cattle where it causes a systemic disease. Also, it can colonize other hosts such as chickens and mice, which can act as reservoirs of this serotype. Salmonella Dublin harbors the genes for both T6SS(SPI-6) and T6SS(SPI-19). This study has determined the contribution of T6SS(SPI-6) and T6SS(SPI-19) to host-colonization by Salmonella Dublin using avian and murine models of infection. Competitive index experiments showed that, a mutant strain lacking both T6SSs (∆T6SS(SPI-6)/∆T6SS(SPI-19)) presents a strong colonization defect in cecum of chickens, similar to the defect observed for the ∆T6SS(SPI-6) mutant, suggesting that this serotype requires a functional T6SS(SPI-6) for efficient colonization of the avian gastrointestinal tract. Colonization of mice was also defective, although to a lesser extent than in chickens. In contrast, the T6SS(SPI-19) was not necessary for colonization of either chickens or mice. Transfer of T6SS(SPI-6), but not T6SS(SPI-19), restored the ability of the double mutant to colonize both animal hosts. Our data indicate that Salmonella Dublin requires only the T6SS(SPI-6) for efficient colonization of mice and chickens, and that the T6SS(SPI-6) and T6SS(SPI-19) are not functionally redundant.

  19. Flirting with disaster: short-term mating orientation and hostile sexism predict different types of sexual harassment.

    PubMed

    Diehl, Charlotte; Rees, Jonas; Bohner, Gerd

    2012-01-01

    We combine evolutionary and sociocultural accounts of sexual harassment, proposing that sexuality-related and hostility-related motives lead to different types of harassment. Specifically, men's short-term mating orientation (STMO) was hypothesized to predict only unwanted sexual attention but not gender harassment, whereas men's hostile sexism (HS) was hypothesized to predict both unwanted sexual attention and gender harassment. As part of an alleged computer-chat task, 100 male students could send sexualized personal remarks (representing unwanted sexual attention), sexist jokes (representing gender harassment), or nonharassing material to an attractive female target. Independently, participants' STMO, HS, and sexual harassment myth acceptance (SHMA) were assessed. Correlational and path analyses revealed that STMO specifically predicted unwanted sexual attention, whereas HS predicted both unwanted sexual attention and gender harassment. Furthermore, SHMA fully mediated the effect of HS on gender harassment, but did not mediate effects of STMO or HS on unwanted sexual attention. Results are discussed in relation to motivational explanations for sexual harassment and antiharassment interventions.

  20. Mutations in XRS2 and RAD50 delay but do not prevent mating-type switching in Saccharomyces cerevisiae.

    PubMed Central

    Ivanov, E L; Sugawara, N; White, C I; Fabre, F; Haber, J E

    1994-01-01

    In Saccharomyces cerevisiae, a large number of genes in the RAD52 epistasis group has been implicated in the repair of chromosomal double-strand breaks and in both mitotic and meiotic homologous recombination. While most of these genes are essential for yeast mating-type (MAT) gene switching, neither RAD50 nor XRS2 is required to complete this specialized mitotic gene conversion process. Using a galactose-inducible HO endonuclease gene to initiate MAT switching, we have examined the effect of null mutations of RAD50 and of XRS2 on intermediate steps of this recombination event. Both rad50 and xrs2 mutants exhibit a marked delay in the completion of switching. Both mutations reduce the extent of 5'-to-3' degradation from the end of the HO-created double-strand break. The steps of initial strand invasion and new DNA synthesis are delayed by approximately 30 min in mutant cells. However, later events are still further delayed, suggesting that XRS2 and RAD50 affect more than one step in the process. In the rad50 xrs2 double mutant, the completion of MAT switching is delayed more than in either single mutant, without reducing the overall efficiency of the process. The XRS2 gene encodes an 854-amino-acid protein with no obvious similarity to the Rad50 protein or to any other protein in the database. Overexpression of RAD50 does not complement the defects in xrs2 or vice versa. Images PMID:8164689

  1. A DTX/MATE-type transporter facilitates abscisic acid efflux and modulates ABA sensitivity and drought tolerance in Arabidopsis.

    PubMed

    Zhang, Haiwen; Zhu, Huifen; Pan, Yajun; Yu, Yuexuan; Luan, Sheng; Li, Legong

    2014-10-01

    Abscisic acid (ABA) regulates numerous physiological and developmental processes in plants. Recent studies identify intracellular ABA receptors, implicating the transport of ABA across cell membranes as crucial for ABA sensing and response. Here, we report that a DTX/Multidrug and Toxic Compound Extrusion (MATE) family member in Arabidopsis thaliana, AtDTX50, functions as an ABA efflux transporter. When expressed heterologously in both an Escherichia coli strain and Xenopus oocyte cells, AtDTX50 was found to facilitate ABA efflux. Furthermore, dtx50 mutant mesophyll cells preloaded with ABA released less ABA compared with the wild-type (WT). The AtDTX50 gene was expressed mainly in the vascular tissues and guard cells and its expression was strongly up-regulated by exogenous ABA. The AtDTX50::GFP fusion protein was localized predominantly to the plasma membrane. The dtx50 mutant plants were observed to be more sensitive to ABA in growth inhibition. In addition, compared with the WT, dtx50 mutant plants were more tolerant to drought with lower stomatal conductance, consistent with its function as an ABA efflux carrier in guard cells.

  2. Three Additional Linkage Groups That Repress Transcription and Meiotic Recombination in the Mating-Type Region of Schizosaccharomyces Pombe

    PubMed Central

    Thon, G.; Cohen, A.; Klar, A. J.

    1994-01-01

    The mating-type genes of Schizosaccharomyces pombe are found at three locations in the same chromosomal region. These genes are in an active configuration at the mat1 locus and in an inactive configuration at the mat2 and mat3 loci. The mechanism that represses transcription of mat2 and mat3 also inactivates other promoters introduced nearby and is accompanied by a block to meiotic recombination in the mat2-mat3 interval, suggesting that this mechanism involves a particular chromatin structure. We present evidence that the transcription and recombination blocks require three newly defined trans-acting loci, clr2, clr3 and clr4, in addition to the previously identified clr1, rik1 and swi6 loci. We also investigated the role of mat2 cis-acting sequences in silencing. Four cis-acting elements that repress mat2 in a plasmid context were previously identified. Deletion of two of these elements proved to have little effect in a chromosomal context. However, when combined with mutations in trans-acting genes, deletion of the same two elements greatly enhanced mat2 expression. The observed cumulative effects suggest a redundancy in the silencing mechanism. PMID:8001791

  3. An external loop region of domain III of dengue virus type 2 envelope protein is involved in serotype-specific binding to mosquito but not mammalian cells.

    PubMed

    Hung, Jan-Jong; Hsieh, Meng-Ti; Young, Ming-Jer; Kao, Chuan-Liang; King, Chwan-Chuen; Chang, Wen

    2004-01-01

    Dengue virus (DV) is a flavivirus and infects mammalian cells through mosquito vectors. This study investigates the roles of domain III of DV type 2 envelope protein (EIII) in DV binding to the host cell. Recombinant EIII interferes with DV infection to BHK21 and C6/36 cells by blocking dengue virion adsorption to these cells. Inhibition of EIII on BHK21 cells was broad with no serotype specificity; however, inhibition of EIII on C6/36 cells was relatively serotype specific. Soluble heparin completely blocks binding of EIII to BHK21 cells, suggesting that domain III binds mainly to cell surface heparan sulfates. This suggestion is supported by the observation that EIII binds very weakly to gro2C and sog9 mutant mammalian cell lines that lack heparan sulfate. In contrast, heparin does not block binding of EIII to mosquito cells. Furthermore, a synthetic peptide that includes amino acids (aa) 380 to 389 of EIII, IGVEPGQLKL, inhibits binding of EIII to C6/36 but not BHK21 cells. This peptide corresponds to a lateral loop region on domain III of E protein, indicating a possible role of this loop in binding to mosquito cells. In summary, these results suggest that EIII plays an important role in binding of DV type 2 to host cells. In addition, EIII interacts with heparan sulfates when binding to BHK21 cells, and a loop region containing aa 380 to 389 of EIII may participate in DV type 2 binding to C6/36 cells.

  4. An External Loop Region of Domain III of Dengue Virus Type 2 Envelope Protein Is Involved in Serotype-Specific Binding to Mosquito but Not Mammalian Cells

    PubMed Central

    Hung, Jan-Jong; Hsieh, Meng-Ti; Young, Ming-Jer; Kao, Chuan-Liang; King, Chwan-Chuen; Chang, Wen

    2004-01-01

    Dengue virus (DV) is a flavivirus and infects mammalian cells through mosquito vectors. This study investigates the roles of domain III of DV type 2 envelope protein (EIII) in DV binding to the host cell. Recombinant EIII interferes with DV infection to BHK21 and C6/36 cells by blocking dengue virion adsorption to these cells. Inhibition of EIII on BHK21 cells was broad with no serotype specificity; however, inhibition of EIII on C6/36 cells was relatively serotype specific. Soluble heparin completely blocks binding of EIII to BHK21 cells, suggesting that domain III binds mainly to cell surface heparan sulfates. This suggestion is supported by the observation that EIII binds very weakly to gro2C and sog9 mutant mammalian cell lines that lack heparan sulfate. In contrast, heparin does not block binding of EIII to mosquito cells. Furthermore, a synthetic peptide that includes amino acids (aa) 380 to 389 of EIII, IGVEPGQLKL, inhibits binding of EIII to C6/36 but not BHK21 cells. This peptide corresponds to a lateral loop region on domain III of E protein, indicating a possible role of this loop in binding to mosquito cells. In summary, these results suggest that EIII plays an important role in binding of DV type 2 to host cells. In addition, EIII interacts with heparan sulfates when binding to BHK21 cells, and a loop region containing aa 380 to 389 of EIII may participate in DV type 2 binding to C6/36 cells. PMID:14671119

  5. Divergence of the dengue virus type 2 Cosmopolitan genotype associated with two predominant serotype shifts between 1 and 2 in Surabaya, Indonesia, 2008-2014.

    PubMed

    Kotaki, Tomohiro; Yamanaka, Atsushi; Mulyatno, Kris Cahyo; Churrotin, Siti; Sucipto, Teguh Hari; Labiqah, Amaliah; Ahwanah, Nur Laila Fitriati; Soegijanto, Soegeng; Kameoka, Masanori; Konishi, Eiji

    2016-01-01

    Indonesia is one of the biggest dengue endemic countries, and, thus, is an important place to investigate the evolution of dengue virus (DENV). We have continuously isolated DENV in Surabaya, the second biggest city in Indonesia, since 2008. We previously reported sequential changes in the predominant serotype from DENV type 2 (DENV-2) to DENV type 1 (DENV-1) in November 2008 and from DENV-1 to DENV-2 in July 2013. The predominance of DENV-2 continued in 2014, but not in 2015. We herein phylogenetically investigated DENV-2 transitions in Surabaya between 2008 and 2014 to analyze the divergence and evolution of DENV-2 concomitant with serotype shifts. All DENV-2 isolated in Surabaya were classified into the Cosmopolitan genotype, and further divided into 6 clusters. Clusters 1-3, dominated by Surabaya strains, were defined as the "Surabaya lineage". Clusters 4-6, dominated by strains from Singapore, Malaysia, and many parts of Indonesia, were the "South East Asian lineage". The most recent common ancestor of these strains existed in 1988, coinciding with the time that an Indonesian dengue outbreak took place. Cluster 1 appeared to be unique because no other DENV-2 isolate was included in this cluster. The predominance of DENV-2 in 2008 and 2013-14 were caused by cluster 1, whereas clusters 2 and 3 sporadically emerged in 2011 and 2012. The characteristic amino acids of cluster 1, E-170V and E-282Y, may be responsible for its prevalence in Surabaya. No amino acid difference was observed in the envelope region between strains in 2008 and 2013-14, suggesting that the re-emergence of DENV-2 in Surabaya was due to the loss or decrease of herd immunity in the 5-year period when DENV-2 subsided. The South East Asian lineage primarily emerged in Surabaya in 2014, probably imported from other parts of Indonesia or foreign countries.

  6. Blind comparison of traditional serotyping with three multiplex PCRs for the identification of Salmonella serotypes.

    PubMed

    Herrera-León, Silvia; Ramiro, Raquel; Arroyo, Margarita; Díez, Rosa; Usera, Miguel Angel; Echeita, Maria Aurora

    2007-03-01

    Salmonella serotypes are defined on the basis of somatic (O) antigens which define the serogroup and flagellar (H) factor antigens, both of which are present in the cell wall of Salmonella. Most Salmonella organisms alternatively express phase-1 or phase-2 flagellar antigens encoded by fliC and fljB genes, respectively. Our group previously published two multiplex PCRs for distinguishing the most common first- and second-phase antigens. In this paper we describe a third multiplex PCR to identify the most common serogroups (O:B; O:C1; O:C2; O:D and O:E). The combination of these three PCRs enabled us to completely serotype organisms belonging to the Salmonella species. This multiplex PCR includes 10 primers. A total of 67 Salmonella strains belonging to 32 different serotypes were tested. Each strain generated one serogroup-specific fragment ranging between 162 and 615bp. Twenty-eight strains belonging to 21 serotypes, with a serogroup different from those tested in this work, did not generate any fragments. To compare molecular serotyping with traditional serotyping, 500 strains, received according to the order of arrival in the laboratory, were serotyped using both methods. The three multiplex PCRs were able to serotype 84.6% of the tested strains. This method was found to be very helpful in our laboratory as an alternative method for typing strains causing outbreaks, and it can be used to supplement conventional serotyping, since it is also applicable to motionless and rough strains.

  7. Fine-scale spatial genetic structure of the black truffle (Tuber melanosporum) investigated with neutral microsatellites and functional mating type genes.

    PubMed

    Murat, Claude; Rubini, Andrea; Riccioni, Claudia; De la Varga, Herminia; Akroume, Emila; Belfiori, Beatrice; Guaragno, Marco; Le Tacon, François; Robin, Christophe; Halkett, Fabien; Martin, Francis; Paolocci, Francesco

    2013-07-01

    The genetic structure of ectomycorrhizal (ECM) fungal populations results from both vegetative and sexual propagation. In this study, we have analysed the spatial genetic structure of Tuber melanosporum populations, a heterothallic ascomycete that produces edible fruit bodies. Ectomycorrhizas from oaks and hazels from two orchards were mapped and genotyped using simple sequence repeat markers and the mating type locus. The distribution of the two T. melanosporum mating types was also monitored in the soil. In one orchard, the genetic profiles of the ascocarps were compared with those of the underlying mycorrhizas. A pronounced spatial genetic structure was found. The maximum genet sizes were 2.35 and 4.70 m in the two orchards, with most manifesting a size < 1 m. Few genets persisted throughout two seasons. A nonrandom distribution pattern of the T. melanosporum was observed, resulting in field patches colonized by genets that shared the same mating types. Our findings suggest that competition occurs between genets and provide basic information on T. melanosporum propagation patterns that are relevant for the management of productive truffle orchards.

  8. Cost of mating and insemination capacity of a genetically modified mosquito Aedes aegypti OX513A compared to its wild type counterpart.

    PubMed

    Bargielowski, Irka; Alphey, Luke; Koella, Jacob C

    2011-01-01

    The idea of implementing genetics-based insect control strategies modelled on the traditional SIT is becoming increasingly popular. In this paper we compare a genetically modified line of Aedes aegypti carrying a tetracycline repressible, lethal positive feedback system (OX513A) with its wild type counterpart with respect to their insemination capacities and the cost of courtship and mating. Genetically modified males inseminated just over half as many females as the wild type males during their lifetime. Providing days of rest from mating had no significant effect on the total number of females inseminated by males of either line, but it did increase their longevity. Producing sperm had a low cost in terms of energy investment; the cost of transferring this sperm to a receptive female was much higher. Continued mating attempts with refractory females suggest that males could not identify refractory females before investing substantial energy in courtship. Although over a lifetime OX513A males inseminated fewer females, the number of females inseminated over the first three days, was similar between males of the two lines, suggesting that the identified cost of RIDL may have little impact on the outcome of SIT-based control programmes with frequent releases of the genetically modified males.

  9. Regulation of budding yeast mating-type switching donor preference by the FHA domain of Fkh1.

    PubMed

    Li, Jin; Coïc, Eric; Lee, Kihoon; Lee, Cheng-Sheng; Kim, Jung-Ae; Wu, Qiuqin; Haber, James E

    2012-01-01

    During Saccharomyces cerevisiae mating-type switching, an HO endonuclease-induced double-strand break (DSB) at MAT is repaired by recombining with one of two donors, HMLα or HMRa, located at opposite ends of chromosome III. MATa cells preferentially recombine with HMLα; this decision depends on the Recombination Enhancer (RE), located about 17 kb to the right of HML. In MATα cells, HML is rarely used and RE is bound by the MATα2-Mcm1 corepressor, which prevents the binding of other proteins to RE. In contrast, in MATa cells, RE is bound by multiple copies of Fkh1 and a single copy of Swi4/Swi6. We report here that, when RE is replaced with four LexA operators in MATa cells, 95% of cells use HMR for repair, but expression of a LexA-Fkh1 fusion protein strongly increases HML usage. A LexA-Fkh1 truncation, containing only Fkh1's phosphothreonine-binding FHA domain, restores HML usage to 90%. A LexA-FHA-R80A mutant lacking phosphothreonine binding fails to increase HML usage. The LexA-FHA fusion protein associates with chromatin in a 10-kb interval surrounding the HO cleavage site at MAT, but only after DSB induction. This association occurs even in a donorless strain lacking HML. We propose that the FHA domain of Fkh1 regulates donor preference by physically interacting with phosphorylated threonine residues created on proteins bound near the DSB, thus positioning HML close to the DSB at MAT. Donor preference is independent of Mec1/ATR and Tel1/ATM checkpoint protein kinases but partially depends on casein kinase II. RE stimulates the strand invasion step of interchromosomal recombination even for non-MAT sequences. We also find that when RE binds to the region near the DSB at MATa then Mec1 and Tel1 checkpoint kinases are not only able to phosphorylate histone H2A (γ-H2AX) around the DSB but can also promote γ-H2AX spreading around the RE region.

  10. Heteroduplex formation and mismatch repair of the "stuck" mutation during mating-type switching in Saccharomyces cerevisiae.

    PubMed Central

    Ray, B L; White, C I; Haber, J E

    1991-01-01

    We sequenced two alleles of the MATa locus of Saccharomyces cerevisiae that reduce homothallic switching and confer viability to HO rad52 strains. Both the MATa-stk (J. E. Haber, W. T. Savage, S. M. Raposa, B. Weiffenbach, and L. B. Rowe, Proc. Natl. Acad. Sci. USA 77:2824-2828, 1980) and MATa-survivor (R. E. Malone and D. Hyman, Curr. Genet. 7:439-447, 1983) alleles result from a T----A base change at position Z11 of the MAT locus. These strains also contain identical base substitutions at HMRa, so that the mutation is reintroduced when MAT alpha switches to MATa. Mating-type switching in a MATa-stk strain relative to a MATa Z11T strain is reduced at least 50-fold but can be increased by expression of HO from a galactose-inducible promoter. We confirmed by Southern analysis that the Z11A mutation reduced the efficiency of double-strand break formation compared with the Z11T variant; the reduction was more severe in MAT alpha than in MATa. In MAT alpha, the Z11A mutation also creates a mat alpha 1 (sterile) mutation that distinguishes switches of MATa-stk to either MAT alpha or mat alpha 1-stk. Pedigree analysis of cells induced to switch in G1 showed that MATa-stk switched frequently (23% of the time) to produce one mat alpha 1-stk and one MAT alpha progeny. This postswitching segregation suggests that Z11 was often present in heteroduplex DNA that was not mismatch repaired. When mismatch repair was prevented by deletion of the PMS1 gene, there was an increase in the proportion of mat alpha 1-stk/MAT alpha sectors (59%) and in pairs of switched cells that both retained the stk mutation (27%). We conclude that at least one strand of DNA only 4 bp from the HO cut site is not degraded in most of the gene conversion events that accompany MAT switching. Images PMID:1922052

  11. Heteroduplex formation and mismatch repair of the "stuck" mutation during mating-type switching in Saccharomyces cerevisiae.

    PubMed

    Ray, B L; White, C I; Haber, J E

    1991-10-01

    We sequenced two alleles of the MATa locus of Saccharomyces cerevisiae that reduce homothallic switching and confer viability to HO rad52 strains. Both the MATa-stk (J. E. Haber, W. T. Savage, S. M. Raposa, B. Weiffenbach, and L. B. Rowe, Proc. Natl. Acad. Sci. USA 77:2824-2828, 1980) and MATa-survivor (R. E. Malone and D. Hyman, Curr. Genet. 7:439-447, 1983) alleles result from a T----A base change at position Z11 of the MAT locus. These strains also contain identical base substitutions at HMRa, so that the mutation is reintroduced when MAT alpha switches to MATa. Mating-type switching in a MATa-stk strain relative to a MATa Z11T strain is reduced at least 50-fold but can be increased by expression of HO from a galactose-inducible promoter. We confirmed by Southern analysis that the Z11A mutation reduced the efficiency of double-strand break formation compared with the Z11T variant; the reduction was more severe in MAT alpha than in MATa. In MAT alpha, the Z11A mutation also creates a mat alpha 1 (sterile) mutation that distinguishes switches of MATa-stk to either MAT alpha or mat alpha 1-stk. Pedigree analysis of cells induced to switch in G1 showed that MATa-stk switched frequently (23% of the time) to produce one mat alpha 1-stk and one MAT alpha progeny. This postswitching segregation suggests that Z11 was often present in heteroduplex DNA that was not mismatch repaired. When mismatch repair was prevented by deletion of the PMS1 gene, there was an increase in the proportion of mat alpha 1-stk/MAT alpha sectors (59%) and in pairs of switched cells that both retained the stk mutation (27%). We conclude that at least one strand of DNA only 4 bp from the HO cut site is not degraded in most of the gene conversion events that accompany MAT switching.

  12. Foot-and-mouth disease vaccine potency testing: the influence of serotype, type of adjuvant, valency, fractionation method, and virus culture on the dose-response curve in cattle.

    PubMed

    Jamal, Syed M; Bouma, Annemarie; van den Broek, Jan; Stegeman, Arjan; Chénard, Gilles; Dekker, Aldo

    2008-11-25

    The aim of this study was to determine a relationship between vaccine potency (amount of PD50 per dose) and fraction of clinically protected cattle following homologous challenge with infectious foot-and-mouth disease (FMD) virus, and to determine the effect of method of fractionation, serotype, type of adjuvant, valency and type of virus culture on the dose-response curve. Data from 297 potency tests of FMD vaccines, comprising 4004 vaccinated cattle, performed at the FMD vaccine production facility in the Netherlands, were used for the present study. A generalised linear mixed effect model was used to analyse the results. Our study showed that the relation between FMD vaccine potency and fraction protected was also affected by the serotype and type of adjuvant. No common level of protection could be assigned to all FMD vaccines with the same amount of PD50 per dose, this information is essential when designing a new standard FMD vaccines control.

  13. Evaluation of Molecular Methods for Serotyping Shigella flexneri

    PubMed Central

    Gentle, Amy; Ashton, Philip M.; Dallman, Timothy J.

    2016-01-01

    Shigella flexneri can be phenotypically serotyped using antisera raised to type-specific somatic antigens and group factor antigens and genotypically serotyped using PCR targeting O-antigen synthesis or modification genes. The aim of this study was to evaluate a real-time PCR for serotyping S. flexneri and to use whole-genome sequencing (WGS) to investigate the phenotypic and genotypic serotype identifications. Of the 244 cultures tested retrospectively, 226 (92.6%) had concordant results between phenotypic serotyping and PCR. Seventy of the 244 isolates (including 15 of the 18 isolates where a serotype-PCR mismatch was identified) were whole-genome sequenced, and the serotype was derived from the genome. Discrepant results between the phenotypic and genotypic tests were attributed to insertions/deletions or point mutations identified in O-antigen synthesis or modification genes, rendering them dysfunctional; inconclusive serotyping results due to nonspecific cross-reactions; or novel genotypes. Phylogenetic analysis of the WGS data indicated that the serotype, regardless of whether it was phenotypically or genotypically determined, was a weak predictor of phylogenetic relationships between strains of S. flexneri. WGS data provided both genome-derived serotyping, thus supporting backward compatibility with historical data and facilitating data exchange in the community, and more robust and discriminatory typing at the single-nucleotide-polymorphism level. PMID:26984974

  14. Genetic diversity and mating type distribution of Tuber melanosporum and their significance to truffle cultivation in artificially planted truffieres in Australia.

    PubMed

    Linde, C C; Selmes, H

    2012-09-01

    Tuber melanosporum is a truffle native to Europe and is cultivated in countries such as Australia for the gastronomic market, where production yields are often lower than expected. We assessed the genetic diversity of T. melanosporum with six microsatellite loci to assess the effect of genetic drift on truffle yield in Australia. Genetic diversity as assessed on 210 ascocarps revealed a higher allelic diversity compared to previous studies from Europe, suggesting a possible genetic expansion and/or multiple and diverse source populations for inoculum. The results also suggest that the single sequence repeat diversity of locus ME2 is adaptive and that, for example, the probability of replication errors is increased for this locus. Loss of genetic diversity in Australian populations is therefore not a likely factor in limiting ascocarp production. A survey of nursery seedlings and trees inoculated with T. melanosporum revealed that <70% of seedlings and host trees were colonized with T. melanosporum and that some trees had been contaminated by Tuber brumale, presumably during the inoculation process. Mating type (MAT1-1-1 and MAT1-2-1) analyses on seedling and four- to ten-year-old host trees found that 100% of seedlings but only approximately half of host trees had both mating types present. Furthermore, MAT1-1-1 was detected significantly more commonly than MAT1-2-1 in established trees, suggesting a competitive advantage for MAT1-1-1 strains. This study clearly shows that there are more factors involved in ascocarp production than just the presence of both mating types on host trees.

  15. Mating-type switching by chromosomal inversion in methylotrophic yeasts suggests an origin for the three-locus Saccharomyces cerevisiae system.

    PubMed

    Hanson, Sara J; Byrne, Kevin P; Wolfe, Kenneth H

    2014-11-11

    Saccharomyces cerevisiae has a complex system for switching the mating type of haploid cells, requiring the genome to have three mating-type (MAT)-like loci and a mechanism for silencing two of them. How this system originated is unknown, because the three-locus system is present throughout the family Saccharomycetaceae, whereas species in the sister Candida clade have only one locus and do not switch. Here we show that yeasts in a third clade, the methylotrophs, have a simpler two-locus switching system based on reversible inversion of a section of chromosome with MATa genes at one end and MATalpha genes at the other end. In Hansenula polymorpha the 19-kb invertible region lies beside a centromere so that, depending on the orientation, either MATa or MATalpha is silenced by centromeric chromatin. In Pichia pastoris, the orientation of a 138-kb invertible region puts either MATa or MATalpha beside a telomere and represses transcription of MATa2 or MATalpha2. Both species are homothallic, and inversion of their MAT regions can be induced by crossing two strains of the same mating type. The three-locus system of S. cerevisiae, which uses a nonconservative mechanism to replace DNA at MAT, likely evolved from a conservative two-locus system that swapped genes between expression and nonexpression sites by inversion. The increasing complexity of the switching apparatus, with three loci, donor bias, and cell lineage tracking, can be explained by continuous selection to increase sporulation ability in young colonies. Our results provide an evolutionary context for the diversity of switching and silencing mechanisms.

  16. Tracing the Origin of the Fungal α1 Domain Places Its Ancestor in the HMG-Box Superfamily: Implication for Fungal Mating-Type Evolution

    PubMed Central

    van Tilbeurgh, Herman; Ripoll, Daniel R.; Dixelius, Christina; Turgeon, B. Gillian; Debuchy, Robert

    2010-01-01

    Background Fungal mating types in self-incompatible Pezizomycotina are specified by one of two alternate sequences occupying the same locus on corresponding chromosomes. One sequence is characterized by a gene encoding an HMG protein, while the hallmark of the other is a gene encoding a protein with an α1 domain showing similarity to the Matα1p protein of Saccharomyces cerevisiae. DNA-binding HMG proteins are ubiquitous and well characterized. In contrast, α1 domain proteins have limited distribution and their evolutionary origin is obscure, precluding a complete understanding of mating-type evolution in Ascomycota. Although much work has focused on the role of the S. cerevisiae Matα1p protein as a transcription factor, it has not yet been placed in any of the large families of sequence-specific DNA-binding proteins. Methodology/Principal Findings We present sequence comparisons, phylogenetic analyses, and in silico predictions of secondary and tertiary structures, which support our hypothesis that the α1 domain is related to the HMG domain. We have also characterized a new conserved motif in α1 proteins of Pezizomycotina. This motif is immediately adjacent to and downstream of the α1 domain and consists of a core sequence Y-[LMIF]-x(3)-G-[WL] embedded in a larger conserved motif. Conclusions/Significance Our data suggest that extant α1-box genes originated from an ancestral HMG gene, which confirms the current model of mating-type evolution within the fungal kingdom. We propose to incorporate α1 proteins in a new subclass of HMG proteins termed MATα_HMG. PMID:21170349

  17. Mating-type switching by chromosomal inversion in methylotrophic yeasts suggests an origin for the three-locus Saccharomyces cerevisiae system

    PubMed Central

    Hanson, Sara J.; Byrne, Kevin P.; Wolfe, Kenneth H.

    2014-01-01

    Saccharomyces cerevisiae has a complex system for switching the mating type of haploid cells, requiring the genome to have three mating-type (MAT)–like loci and a mechanism for silencing two of them. How this system originated is unknown, because the three-locus system is present throughout the family Saccharomycetaceae, whereas species in the sister Candida clade have only one locus and do not switch. Here we show that yeasts in a third clade, the methylotrophs, have a simpler two-locus switching system based on reversible inversion of a section of chromosome with MATa genes at one end and MATalpha genes at the other end. In Hansenula polymorpha the 19-kb invertible region lies beside a centromere so that, depending on the orientation, either MATa or MATalpha is silenced by centromeric chromatin. In Pichia pastoris, the orientation of a 138-kb invertible region puts either MATa or MATalpha beside a telomere and represses transcription of MATa2 or MATalpha2. Both species are homothallic, and inversion of their MAT regions can be induced by crossing two strains of the same mating type. The three-locus system of S. cerevisiae, which uses a nonconservative mechanism to replace DNA at MAT, likely evolved from a conservative two-locus system that swapped genes between expression and nonexpression sites by inversion. The increasing complexity of the switching apparatus, with three loci, donor bias, and cell lineage tracking, can be explained by continuous selection to increase sporulation ability in young colonies. Our results provide an evolutionary context for the diversity of switching and silencing mechanisms. PMID:25349420

  18. Binding of the Fkh1 Forkhead Associated Domain to a Phosphopeptide within the Mph1 DNA Helicase Regulates Mating-Type Switching in Budding Yeast

    PubMed Central

    Su, Zhangli; Cherney, Rachel; Choi, Koyi; Denu, John; Zhao, Xiaolan; Fox, Catherine A.

    2016-01-01

    The Saccharomyces cerevisiae Fkh1 protein has roles in cell-cycle regulated transcription as well as a transcription-independent role in recombination donor preference during mating-type switching. The conserved FHA domain of Fkh1 regulates donor preference by juxtaposing two distant regions on chromosome III to promote their recombination. A model posits that this Fkh1-mediated long-range chromosomal juxtaposition requires an interaction between the FHA domain and a partner protein(s), but to date no relevant partner has been described. In this study, we used structural modeling, 2-hybrid assays, and mutational analyses to show that the predicted phosphothreonine-binding FHA domain of Fkh1 interacted with multiple partner proteins. The Fkh1 FHA domain was important for its role in cell-cycle regulation, but no single interaction partner could account for this role. In contrast, Fkh1’s interaction with the Mph1 DNA repair helicase regulated donor preference during mating-type switching. Using 2-hybrid assays, co-immunoprecipitation, and fluorescence anisotropy, we mapped a discrete peptide within the regulatory Mph1 C-terminus required for this interaction and identified two threonines that were particularly important. In vitro binding experiments indicated that at least one of these threonines had to be phosphorylated for efficient Fkh1 binding. Substitution of these two threonines with alanines (mph1-2TA) specifically abolished the Fkh1-Mph1 interaction in vivo and altered donor preference during mating-type switching to the same degree as mph1Δ. Notably, the mph1-2TA allele maintained other functions of Mph1 in genome stability. Deletion of a second Fkh1-interacting protein encoded by YMR144W also resulted in a change in Fkh1-FHA-dependent donor preference. We have named this gene FDO1 for Forkhead one interacting protein involved in donor preference. We conclude that a phosphothreonine-mediated protein-protein interface between Fkh1-FHA and Mph1 contributes

  19. How Well Do Molecular and Pedigree Relatedness Correspond, in Populations with Diverse Mating Systems, and Various Types and Quantities of Molecular and Demographic Data?

    PubMed Central

    Kopps, Anna M.; Kang, Jungkoo; Sherwin, William B.; Palsbøll, Per J.

    2015-01-01

    Kinship analyses are important pillars of ecological and conservation genetic studies with potentially far-reaching implications. There is a need for power analyses that address a range of possible relationships. Nevertheless, such analyses are rarely applied, and studies that use genetic-data-based-kinship inference often ignore the influence of intrinsic population characteristics. We investigated 11 questions regarding the correct classification rate of dyads to relatedness categories (relatedness category assignments; RCA) using an individual-based model with realistic life history parameters. We investigated the effects of the number of genetic markers; marker type (microsatellite, single nucleotide polymorphism SNP, or both); minor allele frequency; typing error; mating system; and the number of overlapping generations under different demographic conditions. We found that (i) an increasing number of genetic markers increased the correct classification rate of the RCA so that up to >80% first cousins can be correctly assigned; (ii) the minimum number of genetic markers required for assignments with 80 and 95% correct classifications differed between relatedness categories, mating systems, and the number of overlapping generations; (iii) the correct classification rate was improved by adding additional relatedness categories and age and mitochondrial DNA data; and (iv) a combination of microsatellite and single-nucleotide polymorphism data increased the correct classification rate if <800 SNP loci were available. This study shows how intrinsic population characteristics, such as mating system and the number of overlapping generations, life history traits, and genetic marker characteristics, can influence the correct classification rate of an RCA study. Therefore, species-specific power analyses are essential for empirical studies. PMID:26134496

  20. How Well Do Molecular and Pedigree Relatedness Correspond, in Populations with Diverse Mating Systems, and Various Types and Quantities of Molecular and Demographic Data?

    PubMed

    Kopps, Anna M; Kang, Jungkoo; Sherwin, William B; Palsbøll, Per J

    2015-06-30

    Kinship analyses are important pillars of ecological and conservation genetic studies with potentially far-reaching implications. There is a need for power analyses that address a range of possible relationships. Nevertheless, such analyses are rarely applied, and studies that use genetic-data-based-kinship inference often ignore the influence of intrinsic population characteristics. We investigated 11 questions regarding the correct classification rate of dyads to relatedness categories (relatedness category assignments; RCA) using an individual-based model with realistic life history parameters. We investigated the effects of the number of genetic markers; marker type (microsatellite, single nucleotide polymorphism SNP, or both); minor allele frequency; typing error; mating system; and the number of overlapping generations under different demographic conditions. We found that (i) an increasing number of genetic markers increased the correct classification rate of the RCA so that up to >80% first cousins can be correctly assigned; (ii) the minimum number of genetic markers required for assignments with 80 and 95% correct classifications differed between relatedness categories, mating systems, and the number of overlapping generations; (iii) the correct classification rate was improved by adding additional relatedness categories and age and mitochondrial DNA data; and (iv) a combination of microsatellite and single-nucleotide polymorphism data increased the correct classification rate if <800 SNP loci were available. This study shows how intrinsic population characteristics, such as mating system and the number of overlapping generations, life history traits, and genetic marker characteristics, can influence the correct classification rate of an RCA study. Therefore, species-specific power analyses are essential for empirical studies.

  1. Identification of Mating Type Genes in the Bipolar Basidiomycetous Yeast Rhodosporidium toruloides: First Insight into the MAT Locus Structure of the Sporidiobolales▿ †

    PubMed Central

    Coelho, Marco A.; Rosa, André; Rodrigues, Nádia; Fonseca, Álvaro; Gonçalves, Paula

    2008-01-01

    Rhodosporidium toruloides is a heterothallic, bipolar, red yeast that belongs to the Sporidiobolales, an order within a major lineage of basidiomycetes, the Pucciniomycotina. In contrast to other basidiomycetes, considerably less is known about the nature of the mating type (MAT) loci that control sexual reproduction in this lineage. Three genes (RHA1, RHA2, and RHA3) encoding precursors of the MAT A1 pheromone (rhodotorucine A) were previously identified and formed the basis for a genome walking approach that led to the identification of additional MAT genes in complementary mating strains of R. toruloides. Two mating type-specific alleles encoding a p21-activated kinase (PAK; Ste20 homolog) were found between the RHA2 and RHA3 genes, and identification in MAT A2 strains of a gene encoding a presumptive pheromone precursor enabled prediction of the structure of rhodotorucine a. In addition, a putative pheromone receptor gene (STE3 homolog) was identified upstream of RHA1. Analyses of genomic data from two closely related species, Sporobolomyces roseus and Sporidiobolus salmonicolor, identified syntenic regions that contain homologs of all the above-mentioned genes. Notably, six novel pheromone precursor genes were uncovered, which encoded, similarly to the RHA genes, multiple tandem copies of the peptide moiety. This suggests that this structure, which is unique among fungal lipopeptide pheromones, seems to be prevalent in red yeasts. Species comparisons provided evidence for a large, multigenic MAT locus structure in the Sporidiobolales, but no putative homeodomain transcription factor genes (which are present in all basidiomycetous MAT loci characterized thus far) could be found in any of the three species in the vicinity of the MAT genes identified. PMID:18408057

  2. Distribution of mating-type alleles and M13 PCR markers in the black leaf spot fungus Mycosphaerella fijiensis of bananas in Brazil.

    PubMed

    Queiroz, C B; Miranda, E C; Hanada, R E; Sousa, N R; Gasparotto, L; Soares, M A; Silva, G F

    2013-02-08

    The fungus Mycosphaerella fijiensis is the causative agent of black sigatoka, which is one of the most destructive diseases of banana plants. Infection with this pathogen results in underdeveloped fruit, with no commercial value. We analyzed the distribution of the M. fijiensis mating-type system and its genetic variability using M13 phage DNA markers. We found a 1:1 distribution of mating-type alleles, indicating MAT1-1 and MAT1-2 idiomorphs. A polymorphism analysis using three different primers for M13 markers showed that only the M13 minisatellite primers generated polymorphic products. We then utilized this polymorphism to characterize 40 isolates from various Brazilian states. The largest genetic distances were found between isolates from the same location and between isolates from different parts of the country. Therefore, there was no correlation between the genetic similarity and the geographic origin of the isolates. The M13 marker was used to generate genetic fingerprints for five isolates; these fingerprints were compared with the band profiles obtained from inter-simple sequence repeat (UBC861) and inter-retrotransposon amplified polymorphism analyses. We found that the M13 marker was more effective than the other two markers for differentiating these isolates.

  3. The Type VI Secretion System Encoded in Salmonella Pathogenicity Island 19 Is Required for Salmonella enterica Serotype Gallinarum Survival within Infected Macrophages

    PubMed Central

    Blondel, Carlos J.; Jiménez, Juan C.; Leiva, Lorenzo E.; Álvarez, Sergio A.; Pinto, Bernardo I.; Contreras, Francisca; Pezoa, David; Santiviago, Carlos A.

    2013-01-01

    Salmonella enterica serotype Gallinarum is the causative agent of fowl typhoid, a disease characterized by high morbidity and mortality that causes major economic losses in poultry production. We have reported that S. Gallinarum harbors a type VI secretion system (T6SS) encoded in Salmonella pathogenicity island 19 (SPI-19) that is required for efficient colonization of chicks. In the present study, we aimed to characterize the SPI-19 T6SS functionality and to investigate the mechanisms behind the phenotypes previously observed in vivo. Expression analyses revealed that SPI-19 T6SS core components are expressed and produced under in vitro bacterial growth conditions. However, secretion of the structural/secreted components Hcp1, Hcp2, and VgrG to the culture medium could not be determined, suggesting that additional signals are required for T6SS-dependent secretion of these proteins. In vitro bacterial competition assays failed to demonstrate a role for SPI-19 T6SS in interbacterial killing. In contrast, cell culture experiments with murine and avian macrophages (RAW264.7 and HD11, respectively) revealed production of a green fluorescent protein-tagged version of VgrG soon after Salmonella uptake. Furthermore, infection of RAW264.7 and HD11 macrophages with deletion mutants of SPI-19 or strains with genes encoding specific T6SS core components (clpV and vgrG) revealed that SPI-19 T6SS contributes to S. Gallinarum survival within macrophages at 20 h postuptake. SPI-19 T6SS function was not linked to Salmonella-induced cytotoxicity or cell death of infected macrophages, as has been described for other T6SS. Our data indicate that SPI-19 T6SS corresponds to a novel tool used by Salmonella to survive within host cells. PMID:23357385

  4. Rapid, selective digestion of mitochondrial DNA in accordance with the matA hierarchy of multiallelic mating types in the mitochondrial inheritance of Physarum polycephalum.

    PubMed

    Moriyama, Y; Kawano, S

    2003-07-01

    Although mitochondria are inherited uniparentally in nearly all eukaryotes, the mechanism for this is unclear. When zygotes of the isogamous protist Physarum polycephalum were stained with DAPI, the fluorescence of mtDNA in half of the mitochondria decreased simultaneously to give small spots and then disappeared completely approximately 1.5 hr after nuclear fusion, while the other mitochondrial nucleoids and all of the mitochondrial sheaths remained unchanged. PCR analysis of single zygote cells confirmed that the loss was limited to mtDNA from one parent. The vacant mitochondrial sheaths were gradually eliminated by 60 hr after mating. Using six mating types, the transmission patterns of mtDNA were examined in all possible crosses. In 39 of 60 crosses, strict uniparental inheritance was confirmed in accordance with a hierarchy of relative sexuality. In the other crosses, however, mtDNA from both parents was transmitted to plasmodia. The ratio of parental mtDNA was estimated to be from 1:1 to 1:10(-4). Nevertheless, the matA hierarchy was followed. In these crosses, the mtDNA was incompletely digested, and mtDNA replicated during subsequent plasmodial development. We conclude that the rapid, selective digestion of mtDNA promotes the uniparental inheritance of mitochondria; when this fails, biparental inheritance occurs.

  5. Monoclonal antibodies to serotype 2 and serotype 15 outer membrane proteins of Neisseria meningitidis and their use in serotyping.

    PubMed Central

    Zollinger, W D; Moran, E E; Connelly, H; Mandrell, R E; Brandt, B

    1984-01-01

    A series of murine monoclonal antibodies to serotype 2 and serotype 15 strains of Neisseria meningitidis were produced which were specific for outer membrane proteins of classes 1, 2, 3, and 5. A panel of eight monoclonal antibodies that exhibited a high degree of serotype specificity when reacted with prototype strains of known serotype were selected for study. Each of the corresponding epitopes was localized on a specific outer membrane protein by means of immunoprecipitation, electroblotting, or both. The serotype 2a-, 2b-, and 2c-specific antibodies bound to the class 2 protein, the serotype 15-specific antibody bound to the class 3 protein, two antibodies (3-1-P1.2 and 3-1-P1.16) bound to class 1 proteins, and two antibodies (1-1-P5.1 and 3-1-P5.2) bound to class 5 proteins. Six of these monoclonal antibodies were used in a spot-blot procedure to survey 122 case isolates (groups B, C, Y, and W135) and 363 carrier isolates (all serogroups) for the presence of the 2a, 2b, 2c, 15, P1.2, and P1.16 epitopes. A total of 66% of the case isolates and 30% of the carrier isolates reacted with one or more of the monoclonal antibodies. The use of monoclonal antibodies for serotyping of meningococci appears to be feasible and easy and appears to have significant advantages over the use of polyclonal typing sera. Images PMID:6434428

  6. Multiple mating reveals complex patterns of assortative mating by personality and body size.

    PubMed

    Montiglio, Pierre-Olivier; Wey, Tina W; Chang, Ann T; Fogarty, Sean; Sih, Andrew

    2016-01-01

    Understanding patterns of non-random mating is central to predicting the consequences of sexual selection. Most studies quantifying assortative mating focus on testing for correlations among partners' phenotypes in mated pairs. Few studies have distinguished between assortative mating arising from preferences for similar partners (expressed by all or a subset of the population) vs. from phenotypic segregation in the environment. Also, few studies have assessed the robustness of assortative mating against temporal changes in social conditions. We tracked multiple matings by stream water striders (Aquarius remigis) across variable social conditions to investigate mating patterns by both body size and behavioural type (personality). We documented temporal changes in partner availability and used a mixed model approach to analyse individual behaviours and changes in mating status recorded on an hourly basis. We assessed whether all or only a subset of individuals in the population expressed a tendency to mate with similar phenotypes. Our analyses took into account variation in the level of competition and in the phenotypes of available partners. Males and females exhibited significant assortative mating by body size: the largest males and females, and the smallest males and females mated together more often than random. However, individuals of intermediate size were equally likely to mate with small, intermediate or large partners. Individuals also displayed two contrasting patterns of assortative mating by personality (activity level). Individuals generally mated preferentially with partners of similar activity level. However, beyond that general trend, individuals with more extreme personalities tended to exhibit disassortative mating: the most active males mated disproportionately with less active females and the least active males tended to mate with more active females. Our analyses thus revealed multiple, distinct patterns of nonrandom mating. These mating

  7. Mating type and ploidy effect on the β-glucosidase activity and ethanol-producing performance of Saccharomyces cerevisiae with multiple δ-integrated bgl1 gene.

    PubMed

    Wang, Jianjun; Ma, Yuanyuan; Zhang, Kun; Yang, Huajun; Liu, Cheng; Zou, Shaolan; Hong, Jiefang; Zhang, Minhua

    2016-08-10

    In order to investigate the effect of mating type and ploidy on enzymatic activity and fermentation performance in yeast with multiple δ-integrated foreign genes, eight ploidy series strains were constructed. The initial haploid strain BGL-a was shown to contain about 19 copies of the bgl1 gene. In rich media containing 2% (w/v) sugar the specific activities of BGL-aα were lower than those of BGL-aa or BGL-αα, which indicates the existence of mating type effects. While the maximum OD660 decreased with rising ploidy, the biomass yield showed no significant difference between the eight strains and the specific activities (expressed as U/mL or U/mg DCW) showed little to no variation. When cellobiose was used as the carbon source and β-glucosidase substrate, β-glucosidase was expressed more quickly and at higher levels than in glucose-containing media. The maximum specific activitiy values obtained were 19.07U/mL and 19.39U/mL for BGL-αα and BGL-aa, repsectively. The anaerobic biomass and ethanol-producing performance in rich media containing 10% cellobiose showed no significant difference among the eight strains. Their maximal ethanol concentrations and corresponding yields ranged from 40.27 to 43.46g/L and 77.56 to 83.71%, respectively. When the acid- and alkali-pretreated corncob (10% solids content) was used, the diploid BGL-aα fermented the best. When urea was used as the only supplemented nutrient, the ethanol titer and yield were 35.65g/L and 83.69%, respectively, while a control experiment using industrial Angel yeast with exogenous β-glucosidase addition gave values of 37.93g/L and 89.04%. The combined effects of δ-integration of bgl1, ploidy and mating type result in BGL-aa or BGL-αα being the optimal choice for enzyme production and BGL-aα being more suitable for cellulosic ethanol fermentation. These results provide valuable information for future yeast breeding and utilization efforts.

  8. Recurrent polymorphic mating type variation in Madagascan Bulbophyllum species (Orchidaceae) exemplifies a high incidence of auto-pollination in tropical orchids.

    PubMed

    Gamisch, Alexander; Fischer, Gunter A; Comes, Hans Peter

    2014-06-01

    The transition from outcrossing to self-fertilization is one of the most common evolutionary changes in angiosperms. The orchid family exemplifies this evolutionary trend but, because of a general lack of large-scale surveys on auto-pollination in orchid taxa, the incidence and modes of auto-pollination among (sub)tropical orchids remain poorly known. In the present study, we assessed the frequency and mode of auto-pollination within and among species of a largely monophyletic group of Madagascan Bulbophyllum. The capacity for autonomous fruit set was investigated by bagging experiments in the greenhouse and the field, complemented with detailed floral micromorphological studies of the gynostemium. Our survey comprises 393 accessions, representing at least 78 species, and thus approximately 37% of the species diversity of the genus in the Madagascan region. Our studies revealed that mating type is directly related to gynostemium structure, most often involving the presence or absence of a physical barrier termed 'rostellum'. As a novel and unexpected finding, we identified eight species of a single lineage of Madagascan Bulbophyllum (termed 'clade C'), in which auto-pollinating morphs (selfers), either lacking a rostellum or (rarely) possessing a stigmatic rostellum, co-exist with their pollinator-dependent conspecifics (outcrossers). We hypothesize that auto-pollination via rostellum abortion has a simple genetic basis, and probably evolved rapidly and recurrently by subtle changes in the timing of rostellum development (heterochrony). Thus, species of clade C may have an intrinsic genetic and developmental lability toward auto-pollination, allowing rapid evolutionary response under environmental, perhaps human-disturbed conditions favouring reproductive assurance. Overall, these findings should stimulate further research on the incidence, evolution, and maintenance of mating type variation in tropical orchids, as well as how they adapt(ed) to changing

  9. Recurrent polymorphic mating type variation in Madagascan Bulbophyllum species (Orchidaceae) exemplifies a high incidence of auto-pollination in tropical orchids

    PubMed Central

    Gamisch, Alexander; Fischer, Gunter A; Comes, Hans Peter

    2014-01-01

    The transition from outcrossing to self-fertilization is one of the most common evolutionary changes in angiosperms. The orchid family exemplifies this evolutionary trend but, because of a general lack of large-scale surveys on auto-pollination in orchid taxa, the incidence and modes of auto-pollination among (sub)tropical orchids remain poorly known. In the present study, we assessed the frequency and mode of auto-pollination within and among species of a largely monophyletic group of Madagascan Bulbophyllum. The capacity for autonomous fruit set was investigated by bagging experiments in the greenhouse and the field, complemented with detailed floral micromorphological studies of the gynostemium. Our survey comprises 393 accessions, representing at least 78 species, and thus approximately 37% of the species diversity of the genus in the Madagascan region. Our studies revealed that mating type is directly related to gynostemium structure, most often involving the presence or absence of a physical barrier termed ‘rostellum’. As a novel and unexpected finding, we identified eight species of a single lineage of Madagascan Bulbophyllum (termed ‘clade C’), in which auto-pollinating morphs (selfers), either lacking a rostellum or (rarely) possessing a stigmatic rostellum, co-exist with their pollinator-dependent conspecifics (outcrossers). We hypothesize that auto-pollination via rostellum abortion has a simple genetic basis, and probably evolved rapidly and recurrently by subtle changes in the timing of rostellum development (heterochrony). Thus, species of clade C may have an intrinsic genetic and developmental lability toward auto-pollination, allowing rapid evolutionary response under environmental, perhaps human-disturbed conditions favouring reproductive assurance. Overall, these findings should stimulate further research on the incidence, evolution, and maintenance of mating type variation in tropical orchids, as well as how they adapt(ed) to changing

  10. Species and Mating-Type Distribution of Tapesia yallundae and T. acuformis and Occurrence of Apothecia in the U.S. Pacific Northwest.

    PubMed

    Douhan, G W; Murray, T D; Dyer, P S

    2002-07-01

    ABSTRACT Eyespot of wheat is caused by the discomycete fungi Tapesia yallundae and T. acuformis. T. yallundae is considered the most important causal agent of the disease in this region but no apothecia of either species have been found in the U.S. Pacific Northwest (PNW). Two compatible isolates of T. yallundae from the PNW were used to inoculate a field plot in the fall of 1998 and apothecia developed in the spring and fall of 2000 on standing wheat stubble. In the spring of 2000, wheat stubble from eight naturally infected fields was examined for the presence of apothecia of T. yallundae and T. acuformis. Apothecia of T. acuformis were found in two fields but no apothecia of T. yallundae were found. This is the first report of apothecia of the eyespot pathogens occurring in the PNW. Species and mating-type distribution of T. yallundae and T. acuformis in the PNW were determined from 817 isolates collected from diseased wheat over 3 years at spatial scales ranging from within fields to across states. In all, 460 isolates were identified as T. yallundae and 357 isolates were identified as T. acuformis with MAT1-1/MAT1-2 ratios not significantly different from 1:1 based on chi(2) tests at most scales tested. The apparent increase in frequency of T. acuformis from previous surveys may indicate a shift in the predominant species causing eyespot. The occurrence of apothecia under field conditions, along with the widespread distribution of mating types of both species, suggests that sexual reproduction may be occurring in both species.

  11. Mating type-specific cell-cell recognition of Saccharomyces cerevisiae: cell wall attachment and active sites of a- and alpha-agglutinin.

    PubMed Central

    Cappellaro, C; Baldermann, C; Rachel, R; Tanner, W

    1994-01-01

    Mating type-specific agglutination of Saccharomyces cerevisiae a and alpha cells depends on the heterophilic interaction of two cell surface glycoproteins, the gene products of AG alpha 1 and AGA2. Evidence is presented with immunogold labelling that the alpha-agglutinin is part of the outer fimbrial cell wall coat. The a-agglutinin is bound via two S-S bridges (Cys7 and Cys50) to a cell wall component, most probably the gene product of AGA1. His273 of alpha-agglutinin has previously been shown to be essential for a- and alpha-agglutinin interaction and a model based on two opposing ion-pairs had been proposed. By site-directed mutagenesis this possibility has now been excluded. With the help of various peptides, either chemically synthesized, obtained by proteolysis of intact glycosylated a-agglutinin or prepared from a fusion protein expressed in Escherichia coli, the biologically active region of a-agglutinin was located at the C-terminus of the molecule. A peptide consisting of the C-terminal 10 amino acids (GSPIN-TQYVF) was active in nanomolar concentrations. Saccharide moieties, therefore, are not essential for the mating type-specific cell-cell interaction; glycosylated peptides are, however, four to five times more active than non-glycosylated ones. Comparisons of the recognition sequences of the S. cerevisiae agglutinins with that of the Dictyostelium contact site A glycoprotein (gp80), as well as with those of the various families of cell adhesion molecules of higher eucaryotes, have been made and are discussed. Images PMID:7957044

  12. Different mating-type-regulated genes affect the DNA repair defects of Saccharomyces RAD51, RAD52 and RAD55 mutants.

    PubMed

    Valencia-Burton, Maria; Oki, Masaya; Johnson, Jean; Seier, Tracey A; Kamakaka, Rohinton; Haber, James E

    2006-09-01

    Saccharomyces cerevisiae cells expressing both a- and alpha-mating-type (MAT) genes (termed mating-type heterozygosity) exhibit higher rates of spontaneous recombination and greater radiation resistance than cells expressing only MATa or MATalpha. MAT heterozygosity suppresses recombination defects of four mutations involved in homologous recombination: complete deletions of RAD55 or RAD57, an ATPase-defective Rad51 mutation (rad51-K191R), and a C-terminal truncation of Rad52, rad52-Delta327. We investigated the genetic basis of MAT-dependent suppression of these mutants by deleting genes whose expression is controlled by the Mata1-Matalpha2 repressor and scoring resistance to both campothecin (CPT) and phleomycin. Haploid rad55Delta strains became more damage resistant after deleting genes required for nonhomologous end-joining (NHEJ), a process that is repressed in MATa/MATalpha cells. Surprisingly, NHEJ mutations do not suppress CPT sensitivity of rad51-K191R or rad52-Delta327. However, rad51-K191R is uniquely suppressed by deleting the RME1 gene encoding a repressor of meiosis or its coregulator SIN4; this effect is independent of the meiosis-specific homolog, Dmc1. Sensitivity of rad52-Delta327 to CPT was unexpectedly increased by the MATa/MATalpha-repressed gene YGL193C, emphasizing the complex ways in which MAT regulates homologous recombination. The rad52-Delta327 mutation is suppressed by deleting the prolyl isomerase Fpr3, which is not MAT regulated. rad55Delta is also suppressed by deletion of PST2 and/or YBR052C (RFS1, rad55 suppressor), two members of a three-gene family of flavodoxin-fold proteins that associate in a nonrandom fashion with chromatin. All three recombination-defective mutations are made more sensitive by deletions of Rad6 and of the histone deacetylases Rpd3 and Ume6, although these mutations are not themselves CPT or phleomycin sensitive.

  13. Serology of oral Actinobacillus actinomycetemcomitans and serotype distribution in human periodontal disease.

    PubMed Central

    Zambon, J J; Slots, J; Genco, R J

    1983-01-01

    Actinobacillus actinomycetemcomitans from the human oral cavity was serologically characterized with rabbit antisera to the type strain NCTC 9710; a number of reference strains, including Y4, ATCC 29522, ATCC 29523, ATCC 29524, NCTC 9709; and our own isolates representative of each of 10 biotypes. Using immunoabsorbed antisera, we identified three distinct serotypes by immunodiffusion and indirect immunofluorescence. Serotype a was represented by ATCC 29523 and SUNYaB 75; serotype b was represented by ATCC 29522 and Y4; and serotype c was represented by NCTC 9710 and SUNYaB 67. Indirect immunofluorescence revealed no reaction between the three A. actinomycetemcomitans serotype-specific antisera and 62 strains representing 23 major oral bacterial species. Distinct from the serotype antigens were at least one A. actinomycetemcomitans species common antigen and an antigen shared with other Actinobacillus species, Haemophilus aphrophilus, and Haemophilus paraphrophilus. All serotype a A. actinomycetemcomitans strains failed to ferment xylose, whereas all serotype b organisms fermented xylose. Serotype c included xylose-positive as well as xylose-negative strains. A total of 301 isolates of A. actinomycetemcomitans from the oral cavity of 74 subjects were serologically categorized by indirect immunofluorescence with serotype-specific rabbit antisera. Each patient harbored only one serotype of A. actinomycetemcomitans. Fourteen healthy subjects, five diabetics, and seventeen adult periodontitis patients exhibited serotypes a and b in approximately equal frequency, whereas serotype c was found less frequently. In contrast, in 29 localized juvenile periodontitis patients, the incidence of serotype b was approximately two times higher than that of serotypes a or c, suggesting a particularly high periodontopathic potential of A. actinomycetemcomitans serotype b strains. In subjects infected with A. actinomycetemcomitans, serum antibodies were detected to the serotype

  14. Serotype-specific neutralizing antibody epitopes of human adenovirus type 3 (HAdV-3) and HAdV-7 reside in multiple hexon hypervariable regions.

    PubMed

    Qiu, Hongling; Li, Xiao; Tian, Xingui; Zhou, Zhichao; Xing, Ke; Li, Haitao; Tang, Ni; Liu, Wenkuan; Bai, Peisheng; Zhou, Rong

    2012-08-01

    Human adenovirus types 3 and 7 (HAdV-3 and HAdV-7) occur epidemically and contribute greatly to respiratory diseases, but there is no currently available licensed recombinant HAdV-3/HAdV-7 bivalent vaccine. Identification of serotype-specific neutralizing antibody (NAb) epitopes for HAdV-3 and HAdV-7 will be beneficial for development of recombinant HAdV-3/HAdV-7 bivalent vaccines. In this study, four NAb epitopes within hexon hypervariable regions (HVRs) were predicted for HAdV-3 and HAdV-7, respectively, by using bioinformatics. Eight hexon chimeric adenovirus vectors with the alternation of only one predicted neutralizing epitope were constructed. Further in vitro and in vivo neutralization assays indicated that E2 (residing in HVR2) and E3 (residing in HVR5) are NAb epitopes for HAdV-7, and E3 plays a more important role in generating NAb responses. Cross-neutralization assays indicated that all four predicted epitopes, R1 to R4, are NAb epitopes for HAdV-3, and R1 (residing in HVR1) plays the most important role in generating NAb responses. Humoral immune responses elicited by the recombinant rAdH7R1 (containing the R1 epitope) were significantly and durably suppressed by HAdV-3-specific NAbs. Surprisingly, the rAdΔE3GFP-specific neutralizing epitope responses induced by rAdMHE3 (R3 replaced by E3) and rAdMHE4 (R4 replaced by E4) were weaker than those of rAdMHE1 (R1 replaced by E1) or rAdMHE2 (R2 relaced by E2) in vitro and in vivo. Furthermore, rAdMHE4 replicated more slowly in HEp-2 cells, and the final yield was about 10-fold lower than that of rAdΔE3GFP. The current findings contribute not only to the development of new adenovirus vaccine candidates, but also to the construction of new gene delivery vectors.

  15. Porcine rotaviruses antigenically related to human rotavirus serotypes 1 and 2.

    PubMed Central

    Bellinzoni, R B; Mattion, N M; Matson, D O; Blackhall, J; La Torre, J L; Scodeller, E A; Urasawa, S; Taniguchi, K; Estes, M K

    1990-01-01

    Fecal samples from rotavirus-infected piglets were characterized by a serotyping enzyme-linked immunosorbent assay (ELISA) by using monoclonal antibodies (MAbs) specific to human serotypes 1, 2, 3, and 4 (D. O. Matson, M. K. Estes, J. W. Burns, H. B. Greenberg, K. Taniguchi, and S. Urasawa, submitted for publication). Rotavirus in 19 of 25 specimens tested from two herds of pigs from Buenos Aires province, Argentina, were classified antigenically as follows: one serotype 1, four serotype 2, two serotype 3, and no serotype 4. Six specimens reacted with both serotype 1 and 2 MAbs, and viruses in six specimens probably belonged to other serotypes because they reacted only with a VP7 common epitope MAb. Two porcine rotavirus fecal samples found to contain both serotype 1 and 2 viruses by the MAb-based test and one found to contain a serotype 2 virus were grown in tissue culture. When plaque-purified preparations of these tissue culture-adapted viruses were analyzed in the serotyping ELISA, the C60 and C86 preparations reacted only as serotype 1 viruses, indicating that the original fecal samples, which showed multiple VP7 reactivities, were heterogeneous and apparently contained two types of viruses. Testing of plaque-purified C134 virus confirmed its serotype 2 reactivity. The MAb-based serotype designations of these viruses also were confirmed by using a neutralization immunoperoxidase focus reduction assay. This is the first report of the occurrence of serotype 1 and 2 rotaviruses in animals. The MAbs originally developed to serotype human rotaviruses can be utilized to type animal rotaviruses. PMID:2157739

  16. Genome-wide identification of target genes of a mating-type α-domain transcription factor reveals functions beyond sexual development.

    PubMed

    Becker, Kordula; Beer, Christina; Freitag, Michael; Kück, Ulrich

    2015-06-01

    Penicillium chrysogenum is the main industrial producer of the β-lactam antibiotic penicillin, the most commonly used drug in the treatment of bacterial infections. Recently, a functional MAT1-1 locus encoding the α-box transcription factor MAT1-1-1 was discovered to control sexual development in P. chrysogenum. As only little was known from any organism about the regulatory functions mediated by MAT1-1-1, we applied chromatin immunoprecipitation combined with next-generation sequencing (ChIP-seq) to gain new insights into the factors that influence MAT1-1-1 functions on a molecular level and its role in genome-wide transcriptional regulatory networks. Most importantly, our data provide evidence for mating-type transcription factor functions that reach far beyond their previously understood role in sexual development. These new roles include regulation of hyphal morphology, asexual development, as well as amino acid, iron, and secondary metabolism. Furthermore, in vitro DNA-protein binding studies and downstream analysis in yeast and P. chrysogenum enabled the identification of a MAT1-1-1 DNA-binding motif, which is highly conserved among euascomycetes. Our studies pave the way to a more general understanding of these master switches for development and metabolism in all fungi, and open up new options for optimization of fungal high production strains.

  17. Replication and segregation of plasmids containing cis-acting regulatory sites of silent mating-type genes in Saccharomyces cerevisiae are controlled by the SIR genes.

    PubMed Central

    Kimmerly, W J; Rine, J

    1987-01-01

    In Saccharomyces cerevisiae, two cis-acting regulatory sites called E and I flank the silent mating-type gene, HMRa, and mediate SIR-dependent transcriptional repression of the a1-a2 promoters. It has been shown previously that the E and I sites have plasmid replicator (ARS) activity. We show in this report that the ARS activity of the E and I sites is governed by the SIR genotype of the cell. In wild-type cells, a plasmid carrying the E site from HMRa (HMR E) in the vector YIp5 exhibited very high mitotic stability at a copy number of approximately 25 per cell. However, in sir2, sir3, or sir4 mutants, plasmids with HMR E had the low mitotic stability characteristic of plasmids containing ARS1, a SIR-independent replicator. Elevated mitotic stability of plasmids that carry HMR E is due to a segregation mechanism provided by SIR and HMR E. In sir2 and sir4 mutants, the plasmid copy number was significantly lowered, suggesting that these gene products also participate in the replication of plasmids carrying HMR E. The phenotype of point mutations introduced at an 11-base-pair ARS consensus sequence present at HMR E indicated that this sequence is functional but not absolutely required for autonomous replication of the plasmid and that it is not required for SIR-dependent mitotic stabilization. A plasmid carrying both a centromere and HMR E exhibited reduced mitotic stability in wild-type cells. This destabilization appeared to be due to antagonism between the segregation functions provided by the centromere and by HMR E. Images PMID:3325822

  18. Identification of a dengue virus type 2 (DEN-2) serotype-specific B-cell epitope and detection of DEN-2-immunized animal serum samples using an epitope-based peptide antigen.

    PubMed

    Wu, Han-Chung; Jung, Mei-Ying; Chiu, Chien-Yu; Chao, Ting-Ting; Lai, Szu-Chia; Jan, Jia-Tsrong; Shaio, Men-Fang

    2003-10-01

    In this study, a serotype-specific monoclonal antibody (mAb), D(2) 16-1 (Ab4), against dengue virus type 2 (DEN-2) was generated. The specificity of Ab4, which recognized DEN-2 non-structural protein 1, was determined by ELISA, immunofluorescence and immunoblotting analyses. The serotype-specific B-cell epitope of Ab4 was identified further from a random phage-displayed peptide library; selected phage clones reacted specifically with Ab4 and did not react with other mAbs. Immunopositive phage clones displayed a consensus motif, His-Arg/Lys-Leu/Ile, and a synthetic peptide corresponding to the phage-displayed peptide bound specifically to Ab4. The His and Arg residues in this epitope were found to be crucial for peptide binding to Ab4 and binding activity decreased dramatically when these residues were changed to Leu. The epitope-based synthetic peptide not only identified serum samples from DEN-2-immunized mice and rabbits by ELISA but also differentiated clearly between serum samples from DEN-2- and Japanese encephalitis virus-immunized mice. This mAb and its epitope-based peptide antigen will be useful for serologic diagnosis of DEN-2 infection. Furthermore, DEN-2 epitope identification makes it feasible to dissect antibody responses to DEN and to address the role of antibodies in the pathogenesis of primary and secondary DEN-2 infections.

  19. Low-impact mating system

    NASA Technical Reports Server (NTRS)

    Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Le, Thang D. (Inventor); Morales, Ray H. (Inventor); Robertson, Brandan R. (Inventor)

    2009-01-01

    An androgynous mating system for mating two exoatmospheric space modules comprising a first mating assembly capable of mating with a second mating assembly; a second mating assembly structurally identical to said first mating assembly, said first mating assembly comprising; a load ring; a plurality of load cell subassemblies; a plurality of actuators; a base ring; a tunnel; a closed loop control system; one or more electromagnets; and one or more striker plates, wherein said one or more electomagnets on said second mating assembly are capable of mating with said one or more striker plates on said first mating assembly, and wherein said one or more striker plates is comprised of a plate of predetermined shape and a 5-DOF mechanism capable of maintaining predetermined contact requirements during said mating of said one or more electromagnets and said one or more striker plates.

  20. Revisitingmolecular serotyping of Streptococcus pneumoniae

    PubMed Central

    2015-01-01

    Background Ninety-two Streptococcus pneumoniae serotypes have been described so far, but the pneumococcal conjugate vaccine introduced in the Brazilian basic vaccination schedule in 2010 covers only the ten most prevalent in the country. Pneumococcal serotype-shifting after massive immunization is a major concern and monitoring this phenomenon requires efficient and accessible serotyping methods. Pneumococcal serotyping based on antisera produced in animals is laborious and restricted to a few reference laboratories. Alternatively, molecular serotyping methods assess polymorphisms in the cps gene cluster, which encodes key enzymes for capsular polysaccharides synthesis in pneumococci. In one such approach, cps-RFLP, the PCR amplified cps loci are digested with an endonuclease, generating serotype-specific fingerprints on agarose gel electrophoresis. Methods In this work, in silico and in vitro approaches were combined to demonstrate that XhoII is the most discriminating endonuclease for cps-RFLP, and to build a database of serotype-specific fingerprints that accommodates the genetic diversity within the cps locus of 92 known pneumococci serotypes. Results The expected specificity of cps-RFLP using XhoII was 76% for serotyping and 100% for serogrouping. The database of cps-RFLP fingerprints was integrated to Molecular Serotyping Tool (MST), a previously published web-based software for molecular serotyping. In addition, 43 isolates representing 29 serotypes prevalent in the state of Minas Gerais, Brazil, from 2007 to 2013, were examined in vitro; 11 serotypes (nine serogroups) matched the respective in silico patterns calculated for reference strains. The remaining experimental patterns, despite their resemblance to their expected in silico patterns, did not reach the threshold of similarity score to be considered a match and were then added to the database. Conclusion The cps-RFLP method with XhoII outperformed the antisera-based and other molecular serotyping

  1. Genomes of Ashbya Fungi Isolated from Insects Reveal Four Mating-Type Loci, Numerous Translocations, Lack of Transposons, and Distinct Gene Duplications

    PubMed Central

    Dietrich, Fred S.; Voegeli, Sylvia; Kuo, Sidney; Philippsen, Peter

    2013-01-01

    The filamentous fungus Ashbya gossypii is a cotton pathogen transmitted by insects. It is readily grown and manipulated in the laboratory and is commercially exploited as a natural overproducer of vitamin B2. Our previous genome analysis of A. gossypii isolate ATCC10895, collected in Trinidad nearly 100 years ago, revealed extensive synteny with the Saccharomyces cerevisiae genome, leading us to use it as a model organism to understand the evolution of filamentous growth. To further develop Ashbya as a model system, we have investigated the ecological niche of A. gossypii and isolated additional strains and a sibling species, both useful in comparative analysis. We isolated fungi morphologically similar to A. gossypii from different plant-feeding insects of the suborder Heteroptera, generated a phylogenetic tree based on rDNA-ITS sequences, and performed high coverage short read sequencing with one A. gossypii isolate from Florida, a new species, Ashbya aceri, isolated in North Carolina, and a genetically marked derivative of ATCC10895 intensively used for functional studies. In contrast to S. cerevisiae, all strains carry four not three mating type loci, adding a new puzzle in the evolution of Ashbya species. Another surprise was the genome identity of 99.9% between the Florida strain and ATCC10895, isolated in Trinidad. The A. aceri and A. gossypii genomes show conserved gene orders rearranged by eight translocations, 90% overall sequence identity, and fewer tandem duplications in the A. aceri genome. Both species lack transposable elements. Finally, our work identifies plant-feeding insects of the suborder Heteroptera as the most likely natural reservoir of Ashbya, and that infection of cotton and other plants may be incidental to the growth of the fungus in its insect host. PMID:23749448

  2. Evidence for minority male mating success and minority female mating disadvantage in Drosophila ananassae.

    PubMed

    Som, Arundhati; Singh, Bashisth N

    2005-03-31

    Frequency-dependent mating success was tested for three pairs of wild-type and mutant strains of Drosophila ananassae, MY and yellow body color (y), PN and claret eye color (ca), and TIR and cut wing (ct). The two strains of each pair were chosen for their approximately equal mating propensities. Multiple-choice experiments, using different experimental procedures, were employed. The tests were carried out by direct observation in Elens-Wattiaux mating chambers with five different sex ratios (4:16, 8:12, 10:10, 12:8, and 16:4). There was no assortative mating and sexual isolation between the strains, based on 2 x 2 contingency chi2 analysis and isolation estimate values. One-sided rare male mating advantages were found in two experiments, one for ca males and the other for wild-type males (TIR). However, no advantage was found for rare males in the experiment with MY and y flies. Mating disadvantages for rare females were found for sex-linked mutants (y and ct). Two different observational methods (removal or direct observation of mating pairs) imparted no overall significant effects on the outcome of the frequency-dependent mating tests.

  3. Emerging Opportunities for Serotypes of Botulinum Neurotoxins

    PubMed Central

    Peng Chen, Zhongxing; Morris, J. Glenn; Rodriguez, Ramon L.; Shukla, Aparna Wagle; Tapia-Núñez, John; Okun, Michael S.

    2012-01-01

    Background: Two decades ago, botulinum neurotoxin (BoNT) type A was introduced to the commercial market. Subsequently, the toxin was approved by the FDA to address several neurological syndromes, involving muscle, nerve, and gland hyperactivity. These syndromes have typically been associated with abnormalities in cholinergic transmission. Despite the multiplicity of botulinal serotypes (designated as types A through G), therapeutic preparations are currently only available for BoNT types A and B. However, other BoNT serotypes are under study for possible clinical use and new clinical indications; Objective: To review the current research on botulinum neurotoxin serotypes A-G, and to analyze potential applications within basic science and clinical settings; Conclusions: The increasing understanding of botulinal neurotoxin pathophysiology, including the neurotoxin’s effects on specific neuronal populations, will help us in tailoring treatments for specific diagnoses, symptoms and patients. Scientists and clinicians should be aware of the full range of available data involving neurotoxin subtypes A-G. PMID:23202312

  4. First report of an outbreak of pneumonia caused by Streptococcus pneumoniae serotype 6A.

    PubMed

    Prebil, Karla; Beović, Bojana; Paragi, Metka; Seme, Katja; Kastrin, Tamara; Plesničar, Blanka Kores; Petek, Bojana; Martinčič, Žiga

    2016-01-01

    Five patients in a geropsychiatric unit of a psychiatric hospital became abruptly ill with pneumonia caused by Streptococcus pneumoniae serotype 6A. Four other residents were colonized with the same serotype, which has previously not been reported in association with pneumonia outbreaks. Furthermore, serotype 6A is not included in all vaccine types, which may be important for the choice of vaccine in some settings. All isolates showed identical pulsed-field gel electrophoresis restriction patterns.

  5. Purification and characterization of serotype 6 fimbriae from Bordetella pertussis and comparison of their properties with serotype 2 fimbriae.

    PubMed Central

    Cowell, J L; Zhang, J M; Urisu, A; Suzuki, A; Steven, A C; Liu, T; Liu, T Y; Manclark, C R

    1987-01-01

    Fimbriae were removed from Bordetella pertussis (serotype 1.3.6) by mechanical shearing and purified by precipitation with ammonium sulfate, pH-dependent precipitation at pH 7.4, followed by two successive extractions of the precipitated fimbriae with 4 M urea. By electron microscopy, the precipitated fimbriae appeared as aggregated bundles of long, relatively straight filaments which were disaggregated to individual flexuous filaments at pH 10.5. These purified fimbriae were identified as serotype 6 agglutinogens, since antibody to the purified fimbriae agglutinated B. pertussis strains serotyped as 1.3.6, 1.2.3.6, or 1.2.3.4.6 but did not agglutinate strains of serotype 1.2.3.4, 1.2.3, or 1.3. In contrast, antibody to serotype 2 fimbriae only agglutinated B. pertussis strains containing serotype 2 agglutinogen. Purified type 6 and 2 fimbriae were found to be weakly cross-reactive by enzyme-linked immunosorbent assay, using polyclonal antibody to each type of fimbria. In an immunoblot assay, polyclonal antibodies to a 22,000-dalton subunit of fimbriae from B. bronchiseptica reacted strongly with the type 2 fimbrial subunit of B. pertussis, but only weakly with the type 6 subunit. When subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protein subunit of the type 6 fimbriae migrated with a molecular weight of 21,500, whereas the type 2 fimbrial subunit had a molecular weight of 22,000. The two types of subunits had similar amino acid compositions and showed amino-terminal sequence homology in 15 of 21 amino acids. The amino-terminal amino acid sequences of the B. pertussis fimbriae were distinct from those reported for fimbriae from other gram-negative bacteria. Neither the type 6 nor the type 2 fimbriae caused hemagglutination when assayed with several types of erythrocytes. Images PMID:2881893

  6. Virus recovery rates for wild-type and live-attenuated vaccine strains of African horse sickness virus serotype 7 in orally infected South African Culicoides species.

    PubMed

    Venter, G J; Paweska, J T

    2007-12-01

    Previously reported virus recovery rates from Culicoides (Avaritia) imicola Kieffer and Culicoides (Avaritia) bolitinos Meiswinkel (Diptera, Ceratopogonidae) orally infected with vaccine strain of African horse sickness virus serotype 7 (AHSV-7) were compared with results obtained from concurrently conducted oral infections with five recent AHSV-7 isolates from naturally infected horses from various localities in South Africa. Culicoides were fed sheep bloods spiked with 10(7.6) TCID(50)/mL of a live-attenuated vaccine strain AHSV-7, and with five field isolates in which virus titre in the bloodmeals ranged from 10(7.1) to 10(8.2) TCID(50)/mL). After an extrinsic incubation of 10 days at 23.5 degrees C, virus recovery rates were significantly higher in C. imicola (13.3%) and C. bolitinos (4.2%) infected with the live-attenuated virus than in midges infected with any of the field isolates. The virus recovery rates for the latter groups ranged from 0% to 9.5% for C. imicola and from 0% to 1.5% for C. bolitinos. The C. imicola population at Onderstepoort was significantly more susceptible to infection with AHSV-7 isolated at Onderstepoort than to the virus strains isolated from other localities. Results of this study suggest that tissue culture attenuation of AHSV-7 does not reduce its ability to orally infect competent Culicoides species and may even lead to enhanced replication in the vector. Furthermore, oral susceptibility in a midge population appears to vary for geographically distinct isolates of AHSV-7.

  7. Molecular diagnosis of non-serotypeable Shigella spp.: problems and prospects.

    PubMed

    Muthuirulandi Sethuvel, Dhiviya Prabaa; Devanga Ragupathi, Naveen Kumar; Anandan, Shalini; Walia, Kamini; Veeraraghavan, Balaji

    2017-02-01

    It is not always possible to identify Shigella serogroups/serotypes by biochemical properties alone. Specific identification requires serotyping. Occasionally, isolates that resemble Shigella spp. biochemically, but are non-agglutinable with available antisera, have been observed. Several mechanisms have been reported to limit the efficiency of the serotyping assay. Serotype conversion is a major mechanism in Shigella spp. to escape protective host immune responses. This easy conversion through significant modification of the O-antigen backbone results in different serotypes, which makes laboratory identification difficult. Furthermore, members of the family Enterobacteriaceae are closely related and there is antigenic cross-over (intra- and inter-specific cross-reaction) which affects the agglutination reaction. The performance of the available methods for identification of non-serotypeable Shigella is discussed here, and reveals them to be non-reliable. This shows a need for an alternative method for identification and typing of Shigella spp.

  8. Salmonella enterica Serotype 4,5,12:i:−, an Emerging Salmonella Serotype That Represents Multiple Distinct Clones ▿ †

    PubMed Central

    Soyer, Y.; Moreno Switt, A.; Davis, M. A.; Maurer, J.; McDonough, P. L.; Schoonmaker-Bopp, D. J.; Dumas, N. B.; Root, T.; Warnick, L. D.; Gröhn, Y. T.; Wiedmann, M.

    2009-01-01

    The prevalence, among human clinical cases, of Salmonella enterica serotype 4,5,12:i:−, a serotype antigenically similar to Salmonella enterica serotype Typhimurium but lacking second-phase flagellar antigens, has increased considerably over the last 10 years. To probe the evolution and ecology of this emerging serotype, we characterized 190 Salmonella isolates initially classified as Salmonella serotypes 4,5,12:i:− (n = 90) and Typhimurium (n = 100) and obtained from various sources in the United States and Spain. These isolates were characterized into six sequence types (determined by multilocus sequence typing [MLST]) and 79 pulsed-field gel electrophoresis types. The majority of Salmonella serotype 4,5,12:i:− and Typhimurium isolates (85 and 84 isolates, respectively) represented a single MLST type. Existing genome information revealed different genome deletions (which included genes responsible for phase 2 flagellum expression) in four Spanish Salmonella serotype 4,5,12:i:− isolates and one U.S. Salmonella serotype 4,5,12:i:− isolate. Fifty-nine isolates of both serotypes, representing different sources and geographical locations as well as different molecular subtypes, were thus screened for the presence of six genes and one specific region, all of which were previously found to show variable presence among Salmonella serotype 4,5,12:i:− and Typhimurium strains. All Salmonella serotype 4,5,12:i:− isolates lacked the phase 2 flagella genes fljA and fljB, which were present in all Salmonella serotype Typhimurium isolates. While all Spanish Salmonella serotype 4,5,12:i:− isolates carried the same deletion surrounding fljAB, all but two U.S. isolates showed a different genomic deletion; the two atypical U.S. isolates represented the “Spanish” deletion genotype and a unique deletion genotype. Salmonella serotype 4,5,12:i:− thus appears to represent at least two common clones, which cannot easily be differentiated with standard diagnostic

  9. Clonal distribution of pneumococcal serotype 19F isolates from Ghana.

    PubMed

    Sparding, Nadja; Dayie, Nicholas T K D; Mills, Richael O; Newman, Mercy J; Dalsgaard, Anders; Frimodt-Møller, Niels; Slotved, Hans-Christian

    2015-04-01

    Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Pneumococcal strains are classified according to their capsular polysaccharide and more than 90 different serotypes are currently known. In this project, three distinct groups of pneumococcal carriage isolates from Ghana were investigated; isolates from healthy children in Tamale and isolates from both healthy and children attending the outpatient department at a hospital in Accra. The isolates were previously identified and characterized by Gram staining, serotyping and susceptibility to penicillin. In this study, isolates of the common serotype 19F were further investigated by Multi-Locus Sequence Typing (MLST). Overall, 14 different Sequence Types (STs) were identified by MLST, of which nine were novel based on the international MLST database. Two clones within serotype 19F seem to circulate in Ghana, a known ST (ST 4194) and a novel ST (ST 9090). ST 9090 was only found in healthy children in Accra, whereas ST 4194 was found equally in all children studied. In the MLST database, other isolates of ST 4194 were also associated with serotype 19F, and these isolates came from other West African countries. The majority of isolates were penicillin intermediate resistant. In conclusion, two clones within serotype 19F were found to be dominating in pneumococcal carriage in Accra and Tamale in Ghana. Furthermore, it seems as though the clonal distribution of serotype 19F may be different from what is currently known in Ghana in that many new clones were identified. This supports the importance of continued monitoring of pneumococcal carriage in Ghana and elsewhere when vaccines, e.g., PCV-13, have been introduced to monitor the possible future spread of antimicrobial resistant clones.

  10. Novel Levofloxacin-Resistant Multidrug-Resistant Streptococcus pneumoniae Serotype 11A Isolates, South Korea

    PubMed Central

    Park, Miey; Kim, Hyun Soo; Kim, Han-Sung; Park, Ji Young; Song, Wonkeun; Cho, Hyoun Chan

    2016-01-01

    Of 608 Streptococcus pneumoniae clinical strains isolated at a hospital in South Korea during 2009–2014, sixteen (2.6%) were identified as levofloxacin resistant. The predominant serotype was 11A (9 isolates). Two novel sequence types of multidrug-resistant S. pneumoniae with serotype 11A were identified, indicating continuous diversification of resistant strains. PMID:27767906

  11. Actinobacillus actinomycetemcomitans serotype e--biotypes, genetic diversity and distribution in relation to periodontal status.

    PubMed

    Doğan, B; Saarela, M H; Jousimies-Somer, H; Alaluusua, S; Asikainen, S

    1999-04-01

    Actinobacillus actinomycetemcomitans isolates from 356 individuals were screened for identification of serotype e in order to investigate its distribution in relation to periodontal status. From subjects with serotype e, 1-6 isolates per subject (n = 61) were genotyped using arbitrarily primed-polymerase chain reaction (AP-PCR) and apaH gene polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) analysis to determine the genetic heterogeneity within the serotype. Furthermore, one serotype e strain per subject was tested for fermentation of 8 carbohydrates for biotyping. Among patients with adult periodontitis (n = 219), localized juvenile periodontitis (n = 55) and other forms of early-onset periodontitis (n = 18) serotypes b, a and c, respectively, were the most frequently detected serotypes. Non-periodontitis subjects (n = 64) were predominantly colonized with serotype c. Serotype e was found in 30 (14%) adult periodontitis patients, 2 (11%) early-onset periodontitis patients and in 5 (8%) non-periodontitis individuals, but in none of the 55 localized juvenile periodontitis patients. AP-PCR distinguished 3 and apaH gene PCR-RFLP analysis 2 genotypes among the 61 A. actinomycetemcomitans serotype e isolates, one genotype per subject. The AP-PCR genotypes 1 and 3 represented the apaH genotype 1 and the AP-PCR genotype 2 the apaH genotype 2. On the basis of variable fermentation of galactose and xylose, 3 biotypes among A. actinomycetemcomitans serotype e were established. Contrary to the absence of A. actinomycetemcomitans serotype e in localized juvenile periodontitis patients, its detection frequency was comparable among other forms of periodontitis and periodontal health. Clinical serotype e isolates form at least 2 genetic types and 3 biotypes.

  12. The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

    PubMed Central

    Metin, Banu; Findley, Keisha; Heitman, Joseph

    2010-01-01

    Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality

  13. Molecular Genetics of Mating Recognition in Basidiomycete Fungi

    PubMed Central

    Casselton, Lorna A.; Olesnicky, Natalie S.

    1998-01-01

    The recognition of compatible mating partners in the basidiomycete fungi requires the coordinated activities of two gene complexes defined as the mating-type genes. One complex encodes members of the homeobox family of transcription factors, which heterodimerize on mating to generate an active transcription regulator. The other complex encodes peptide pheromones and 7-transmembrane receptors that permit intercellular signalling. Remarkably, a single species may have many thousands of cross-compatible mating types because the mating-type genes are multiallelic. Different alleles of both sets of genes are necessary for mating compatibility, and they trigger the initial stages of sexual development—the formation of a specialized filamentous mycelium termed the dikaryon, in which the haploid nuclei remain closely associated in each cell but do not fuse. Three species have been taken as models to describe the molecular structure and organization of the mating-type loci and the genes sequestered within them: the pathogenic smut fungus Ustilago maydis and the mushrooms Coprinus cinereus and Schizophyllum commune. Topics addressed in this review are the roles of the mating-type gene products in regulating sexual development, the molecular basis for multiple mating types, and the molecular interactions that permit different allelic products of the mating type genes to be discriminated. Attention is drawn to the remarkable conservation in the mechanisms that regulate sexual development in basidiomycetes and unicellular ascomycete yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe, a theme which is developed in the general conclusion to include the filamentous ascomycetes Neurospora crassa and Podospora anserina. PMID:9529887

  14. Identification and Expression Analysis of MATE Genes Involved in Flavonoid Transport in Blueberry Plants

    PubMed Central

    Chen, Li; Liu, Yushan; Liu, Hongdi; Kang, Limin; Geng, Jinman; Gai, Yuzhuo; Ding, Yunlong; Sun, Haiyue; Li, Yadong

    2015-01-01

    Multidrug and toxic compound extrusion (MATE) proteins are the most recently identified family of multidrug transporters. In plants, this family is remarkably large compared to the human and bacteria counterpart, highlighting the importance of MATE proteins in this kingdom. Here 33 Unigenes annotated as MATE transporters were found in the blueberry fruit transcriptome, of which eight full-length cDNA sequences were identified and cloned. These proteins are composed of 477–517 residues, with molecular masses ~54 kDa, and theoretical isoelectric points from 5.35 to 8.41. Bioinformatics analysis predicted 10–12 putative transmembrane segments for VcMATEs, and localization to the plasma membrane without an N-terminal signal peptide. All blueberry MATE proteins shared 32.1–84.4% identity, among which VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8, and VcMATE9 were more similar to the MATE-type flavonoid transporters. Phylogenetic analysis showed VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8 and VcMATE9 clustered with MATE-type flavonoid transporters, indicating that they might be involved in flavonoid transport. VcMATE1 and VcMATE4 may be involved in the transport of secondary metabolites, the detoxification of xenobiotics, or the export of toxic cations. Real-time quantitative PCR demonstrated that the expression profile of the eight VcMATE genes varied spatially and temporally. Analysis of expression and anthocyanin accumulation indicated that there were some correlation between the expression profile and the accumulation of anthocyanins. These results showed VcMATEs might be involved in diverse physiological functions, and anthocyanins across the membranes might be mutually maintained by MATE-type flavonoid transporters and other mechanisms. This study will enrich the MATE-based transport mechanisms of secondary metabolite, and provide a new biotechonology strategy to develop better nutritional blueberry cultivars. PMID:25781331

  15. Identification and expression analysis of MATE genes involved in flavonoid transport in blueberry plants.

    PubMed

    Chen, Li; Liu, Yushan; Liu, Hongdi; Kang, Limin; Geng, Jinman; Gai, Yuzhuo; Ding, Yunlong; Sun, Haiyue; Li, Yadong

    2015-01-01

    Multidrug and toxic compound extrusion (MATE) proteins are the most recently identified family of multidrug transporters. In plants, this family is remarkably large compared to the human and bacteria counterpart, highlighting the importance of MATE proteins in this kingdom. Here 33 Unigenes annotated as MATE transporters were found in the blueberry fruit transcriptome, of which eight full-length cDNA sequences were identified and cloned. These proteins are composed of 477-517 residues, with molecular masses ~54 kDa, and theoretical isoelectric points from 5.35 to 8.41. Bioinformatics analysis predicted 10-12 putative transmembrane segments for VcMATEs, and localization to the plasma membrane without an N-terminal signal peptide. All blueberry MATE proteins shared 32.1-84.4% identity, among which VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8, and VcMATE9 were more similar to the MATE-type flavonoid transporters. Phylogenetic analysis showed VcMATE2, VcMATE3, VcMATE5, VcMATE7, VcMATE8 and VcMATE9 clustered with MATE-type flavonoid transporters, indicating that they might be involved in flavonoid transport. VcMATE1 and VcMATE4 may be involved in the transport of secondary metabolites, the detoxification of xenobiotics, or the export of toxic cations. Real-time quantitative PCR demonstrated that the expression profile of the eight VcMATE genes varied spatially and temporally. Analysis of expression and anthocyanin accumulation indicated that there were some correlation between the expression profile and the accumulation of anthocyanins. These results showed VcMATEs might be involved in diverse physiological functions, and anthocyanins across the membranes might be mutually maintained by MATE-type flavonoid transporters and other mechanisms. This study will enrich the MATE-based transport mechanisms of secondary metabolite, and provide a new biotechonology strategy to develop better nutritional blueberry cultivars.

  16. AAV Hybrid Serotypes: Improved Vectors for Gene Delivery

    PubMed Central

    Choi, Vivian W.; McCarty, Douglas M.; Samulski, R. Jude

    2006-01-01

    In recent years, significant efforts have been made on studying and engineering adeno-associated virus (AAV) capsid, in order to increase efficiency in targeting specific cell types that are non-permissive to wild type (wt) viruses and to improve efficacy in infecting only the cell type of interest. With our previous knowledge of the viral properties of the naturally occurring serotypes and the elucidation of their capsid structures, we can now generate capsid mutants, or hybrid serotypes, by various methods and strategies. In this review, we summarize the studies performed on AAV retargeting, and categorize the available hybrid serotypes to date, based on the type of modification: 1) transcapsidation, 2) adsorption of bi-specific antibody to capsid surface, 3) mosaic capsid, and 4) chimeric capsid. Not only these hybrid serotypes could achieve high efficiency of gene delivery to a specific targeted cell type, which can be better-tailored for a particular clinical application, but also serve as a tool for studying AAV biology such as receptor binding, trafficking and genome delivery into the nucleus. PMID:15975007

  17. Mating pheromones of heterobasidiomycetous yeasts

    NASA Astrophysics Data System (ADS)

    Kamiya, Y.; Sakurai, A.

    1981-03-01

    Two mating pheromones, which induce mating tube formation, were isolated from Rhodosporidium toruloides (rhodotorucine A) and Tremella mesenterica (tremerogen A-10). These mating pheromones are lipophilic oligopeptides having S-alkylated cysteine at the C-terminus but different amino acid sequences. Synthetic analogues of these pheromones revealed the structure-activity relationships. Metabolism of rhodotorucine A was also studied by using labeled pheromones.

  18. Genetic Characteristics and Multiple-PCR Development for Capsular Identification of Specific Serotypes of Campylobacter jejuni

    PubMed Central

    Liang, Hao; Zhang, Aiyu; Gu, Yixin; You, Yuanhai; Zhang, Jianzhong; Zhang, Maojun

    2016-01-01

    The polysaccharide capsule (CPS) of Campylobacter jejuni is a virulence factor linked to cell surface carbohydrate diversity which mainly determines the serotypes. Thirty-four CPS gene cluster structures have been published and some of them can be distinguished by multiple-PCR. Penner serotypes HS1/44c, HS2, HS4c, HS19, HS23/36c and HS41 are markers for Guillain—Barré syndrome (GBS). The capsules may contribute to GBS susceptibility. Analysis of 18 CPS loci revealed high gene content diversity and a mosaic nature of the capsule loci, which are possibly due to gene gain/loss events, and demonstrated a high degree of conservation of genes within serotypes/serotype complexes. A method of multiple-PCR was developed to distinguish five specific serotypes and three GBS-related serotypes. Primers specific for each capsule type were designed on the basis of paralogs or a unique DNA region of the CPS locus. The multiple-PCR can distinguish the eight serotypes in two PCRs with sensitivity and specificity of 100% using 227 strains of known Penner type. The multiple-PCR method will help to distinguish serotypes simply and rapidly. PMID:27788180

  19. A molecular scheme for Yersinia enterocolitica patho-serotyping derived from genome-wide analysis.

    PubMed

    Garzetti, Debora; Susen, Rosa; Fruth, Angelika; Tietze, Erhard; Heesemann, Jürgen; Rakin, Alexander

    2014-05-01

    Yersinia enterocolitica is a food-borne, gastro-intestinal pathogen with world-wide distribution. Only 11 serotypes have been isolated from patients, with O:3, O:9, O:8 and O:5,27 being the serotypes most commonly associated with human yersiniosis. Serotype is an important characteristic of Y. enterocolitica strains, allowing differentiation for epidemiology, diagnosis and phylogeny studies. Conventional serotyping, performed by slide agglutination, is a tedious and laborious procedure whose interpretation tends to be subjective, leading to poor reproducibility. Here we present a PCR-based typing scheme for molecular identification and patho-serotyping of Y. enterocolitica. Genome-wide comparison of Y. enterocolitica sequences allowed analysis of the O-antigen gene clusters of different serotypes, uncovering their formerly unknown genomic locations, and selection of targets for serotype-specific amplification. Two multiplex PCRs and one additional PCR were designed and tested on various reference strains and isolates from different origins. Our genotypic assay proved to be highly specific for identification of Y. enterocolitica species, discrimination between virulent and non-virulent strains, distinguishing the main human-related serotypes, and typing of conventionally untypeable strains. This genotyping scheme could be applied in microbiology laboratories as an alternative or complementary method to the traditional phenotypic assays, providing data for epidemiological studies.

  20. Mate Choice Drives Evolutionary Stability in a Hybrid Complex

    PubMed Central

    Morgado-Santos, Miguel; Pereira, Henrique Miguel

    2015-01-01

    Previous studies have shown that assortative mating acts as a driver of speciation by countering hybridization between two populations of the same species (pre-zygotic isolation) or through mate choice among the hybrids (hybrid speciation). In both speciation types, assortative mating promotes speciation over a transient hybridization stage. We studied mate choice in a hybrid vertebrate complex, the allopolyploid fish Squalius alburnoides. This complex is composed by several genomotypes connected by an intricate reproductive dynamics. We developed a model that predicts the hybrid complex can persist when females exhibit particular mate choice patterns. Our model is able to reproduce the diversity of population dynamic outcomes found in nature, namely the dominance of the triploids and the dominance of the tetraploids, depending on female mate choice patterns and frequency of the parental species. Experimental mate choice trials showed that females exhibit the preferences predicted by the model. Thus, despite the known role of assortative mating in driving speciation, our findings suggest that certain mate choice patterns can instead hinder speciation and support the persistence of hybrids over time without speciation or extinction. PMID:26181664

  1. In Vivo and In Vitro Anaerobic Mating in Candida albicans▿

    PubMed Central

    Dumitru, Raluca; Navarathna, Dhammika H. M. L. P.; Semighini, Camile P.; Elowsky, Christian G.; Dumitru, Razvan V.; Dignard, Daniel; Whiteway, Malcolm; Atkin, Audrey L.; Nickerson, Kenneth W.

    2007-01-01

    Candida albicans cells of opposite mating types are thought to conjugate during infection in mammalian hosts, but paradoxically, the mating-competent opaque state is not stable at mammalian body temperatures. We found that anaerobic conditions stabilize the opaque state at 37°C, block production of farnesol, and permit in vitro mating at 37°C at efficiencies of up to 84%. Aerobically, farnesol prevents mating because it kills the opaque cells necessary for mating, and as a corollary, farnesol production is turned off in opaque cells. These in vitro observations suggest that naturally anaerobic sites, such as the efficiently colonized gastrointestinal (GI) tract, could serve as niches for C. albicans mating. In a direct test of mating in the mouse GI tract, prototrophic cells were obtained from auxotrophic parent cells, confirming that mating will occur in this organ. These cells were true mating products because they were tetraploid, mononuclear, and prototrophic, and they contained the heterologous hisG marker from one of the parental strains. PMID:17259544

  2. Salmonella enterica prevalence and serotype distribution in swine at slaughter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this cross-sectional study was to analyze data available from multiple studies conducted by our research team estimating the prevalence of S. enterica, and the serotype distribution in swine at slaughter, based on different sample types. A total of 1,110 pigs from three large capaci...

  3. Isolation and genomic characterization of SfI, a serotype-converting bacteriophage of Shigella flexneri

    PubMed Central

    2013-01-01

    Background All Shigella flexneri serotypes except serotype 6 share a common O-antigen tetrasaccharide backbone and nearly all variations between serotypes are due to glucosyl and/or O-acetyl modifications of the common O unit mediated by glycosyltransferases encoded by serotype-converting bacteriophages. Several S. flexneri serotype-converting phages including SfV, SfX, Sf6 and SfII have been isolated and characterized. However, S. flexneri serotype-converting phage SfI which encodes a type I modification of serotype 1 (1a, 1b, 1c and 1d) had not yet been characterized. Results The SfI phage was induced and purified from a S. flexneri serotype 1a clinical strain 019. Electron microscopy showed that the SfI phage has a hexagonal head and a long contractile tail, characteristic of the members of Myoviridae family. SfI can convert serotype Y to serotype 1a and serotype X to serotype 1d, but cannot convert 10 other S. flexneri serotypes (1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b, 5a, Xv) tested, suggesting that SfI has a narrow host range. Similar to other S. flexneri serotype-converting phages, SfI integrates into the tRNA-thrW gene adjacent to proA of the host chromosome when lysogenized. The complete sequence of the SfI genome was 38,389 bp, encoding 66 open reading frames and two tRNA genes. Phage SfI shares significant homology with S. flexneri phage SfV, Escherichia coli prophage e14 and lambda, and is classified into the lambdoid phage family. SfI was found to use a cos mechanism for DNA packaging similar to that of phage SfV. Conclusions SfI contains features of lambdoid phages and is closely related to S. flexneri phage SfV, E. coli prophage e14 and lambda. The characterization of SfI enhances our understanding of serotype conversion of S. flexneri. PMID:23414301

  4. Bacterial vaccines and serotype replacement: lessons from Haemophilus influenzae and prospects for Streptococcus pneumoniae.

    PubMed Central

    Lipsitch, M.

    1999-01-01

    Conjugate vaccines have reduced the incidence of invasive disease caused by Haemophilus influenzae, type b (Hib), in industrialized countries and may be highly effective against Streptococcus pneumoniae. However, the serotype specificity of these vaccines has led to concern that their use may increase carriage of and disease from serotypes not included in the vaccine. Replacement has not occurred with the use of Hib vaccines but has occurred in trials of pneumococcal vaccines. Mathematical models can be used to elucidate these contrasting outcomes, predict the conditions under which serotype replacement is likely, interpret the results of conjugate vaccine trials, design trials that will better detect serotype replacement (if it occurs), and suggest factors to consider in choosing the serotype composition of vaccines. PMID:10341170

  5. Influences on assortative mating.

    PubMed

    Schmidt, H D; Glavce, C; Hartog, J

    1987-09-01

    Age plays a considerable role in assortative mating. As regards this criterion we can distinguish a "rural, more traditional model" with high values of the coefficients of correlation, and an "urban model" with significantly lower values. Concerning eye and hair colour we find both these models as well as transitional forms. In contrast to this there are no important differences in assortative mating between the rural and urban populations regarding the physical traits. Size of population and length of marriage can strongly influence the values of these correlations. They decrease as the size of the population decreases, in which a person chooses his/her partner. Increasing age of the couples also results in a decrease of these correlations.

  6. The a2 Mating-Type Locus Genes lga2 and rga2 Direct Uniparental Mitochondrial DNA (mtDNA) Inheritance and Constrain mtDNA Recombination During Sexual Development of Ustilago maydis

    PubMed Central

    Fedler, Michael; Luh, Kai-Stephen; Stelter, Kathrin; Nieto-Jacobo, Fernanda; Basse, Christoph W.

    2009-01-01

    Uniparental inheritance of mitochondria dominates among sexual eukaryotes. However, little is known about the mechanisms and genetic determinants. We have investigated the role of the plant pathogen Ustilago maydis genes lga2 and rga2 in uniparental mitochondrial DNA (mtDNA) inheritance during sexual development. The lga2 and rga2 genes are specific to the a2 mating-type locus and encode small mitochondrial proteins. On the basis of identified sequence polymorphisms due to variable intron numbers in mitochondrial genotypes, we could demonstrate that lga2 and rga2 decisively influence mtDNA inheritance in matings between a1 and a2 strains. Deletion of lga2 favored biparental inheritance and generation of recombinant mtDNA molecules in combinations in which inheritance of mtDNA of the a2 partner dominated. Conversely, deletion of rga2 resulted in predominant loss of a2-specific mtDNA and favored inheritance of the a1 mtDNA. Furthermore, expression of rga2 in the a1 partner protected the associated mtDNA from elimination. Our results indicate that Lga2 in conjunction with Rga2 directs uniparental mtDNA inheritance by mediating loss of the a1-associated mtDNA. This study shows for the first time an interplay of mitochondrial proteins in regulating uniparental mtDNA inheritance. PMID:19104076

  7. The a2 mating-type locus genes lga2 and rga2 direct uniparental mitochondrial DNA (mtDNA) inheritance and constrain mtDNA recombination during sexual development of Ustilago maydis.

    PubMed

    Fedler, Michael; Luh, Kai-Stephen; Stelter, Kathrin; Nieto-Jacobo, Fernanda; Basse, Christoph W

    2009-03-01

    Uniparental inheritance of mitochondria dominates among sexual eukaryotes. However, little is known about the mechanisms and genetic determinants. We have investigated the role of the plant pathogen Ustilago maydis genes lga2 and rga2 in uniparental mitochondrial DNA (mtDNA) inheritance during sexual development. The lga2 and rga2 genes are specific to the a2 mating-type locus and encode small mitochondrial proteins. On the basis of identified sequence polymorphisms due to variable intron numbers in mitochondrial genotypes, we could demonstrate that lga2 and rga2 decisively influence mtDNA inheritance in matings between a1 and a2 strains. Deletion of lga2 favored biparental inheritance and generation of recombinant mtDNA molecules in combinations in which inheritance of mtDNA of the a2 partner dominated. Conversely, deletion of rga2 resulted in predominant loss of a2-specific mtDNA and favored inheritance of the a1 mtDNA. Furthermore, expression of rga2 in the a1 partner protected the associated mtDNA from elimination. Our results indicate that Lga2 in conjunction with Rga2 directs uniparental mtDNA inheritance by mediating loss of the a1-associated mtDNA. This study shows for the first time an interplay of mitochondrial proteins in regulating uniparental mtDNA inheritance.

  8. Serotype Distribution and Antimicrobial Susceptibilities of Invasive Streptococcus pneumoniae Isolates from Adults in Korea from 1997 to 2012.

    PubMed

    Kim, Chung Jong; Song, Jin-Su; Choi, Su-Jin; Song, Kyoung Ho; Choe, Pyeong Gyun; Park, Wan Beom; Bang, Ji Hwan; Kim, Eu Suk; Park, Sang Won; Kim, Hong Bin; Kim, Nam-Joong; Kim, Eui-Chong; Oh, Myoung-don

    2016-05-01

    In Republic of Korea, a 7-valent pneumococcal conjugated vaccine (PCV7) was licensed for use in infants in 2003, and 13-valent PCV (PCV13) replaced it since 2010. We investigated trends in serotype distribution and antibiotic susceptibility of pneumococcal isolates from adult patients with invasive pneumococcal diseases (IPD). Invasive pneumococcal isolates from adult patients of ≥ 16 years of age were collected from 1997 to 2012. Serotypes of the isolates were determined by the Quellung reaction. Distribution of serotypes was analyzed according to the vaccine types. Antibiotic susceptibility was tested by using E-test strips. A total of 272 invasive pneumococcal isolates were included. The most common serotypes were serotype 19F (8.5%, 23/272), and serotype 3 (8.1%, 22/272), and 24.6% (67/272) of the isolates were of non-vaccine serotypes. Of the 272 isolates, 2.6% (7/272) were penicillin MICs of ≥ 4 µg/mL. The proportion of the PCV13 serotypes decreased from 63.3% (50/79) in 1997-2003 to 48.6% (17/35) in 2011-2012, whereas that of non-vaccine serotypes was 26.6% (21/79) and 25.7% (9/35), respectively, for the same periods. The proportion of the PCV13 serotypes showed a decreasing trend among adult patients with IPD over the study period.

  9. Contribution of the Type VI Secretion System Encoded in SPI-19 to Chicken Colonization by Salmonella enterica Serotypes Gallinarum and Enteritidis

    PubMed Central

    Blondel, Carlos J.; Yang, Hee-Jeong; Castro, Benjamín; Chiang, Sebastián; Toro, Cecilia S.; Zaldívar, Mercedes; Contreras, Inés; Andrews-Polymenis, Helene L.; Santiviago, Carlos A.

    2010-01-01

    Salmonella Gallinarum is a pathogen with a host range specific to poultry, while Salmonella Enteritidis is a broad host range pathogen that colonizes poultry sub-clinically but is a leading cause of gastrointestinal salmonellosis in humans and many other species. Despite recent advances in our understanding of the complex interplay between Salmonella and their hosts, the molecular basis of host range restriction and unique pathobiology of Gallinarum remain largely unknown. Type VI Secretion System (T6SS) represents a new paradigm of protein secretion that is critical for the pathogenesis of many Gram-negative bacteria. We recently identified a putative T6SS in the Salmonella Pathogenicity Island 19 (SPI-19) of Gallinarum. In Enteritidis, SPI-19 is a degenerate element that has lost most of the T6SS functions encoded in the island. In this work, we studied the contribution of SPI-19 to the colonization of Salmonella Gallinarum strain 287/91 in chickens. Non-polar deletion mutants of SPI-19 and the clpV gene, an essential T6SS component, colonized the ileum, ceca, liver and spleen of White Leghorn chicks poorly compared to the wild-type strain after oral inoculation. Return of SPI-19 to the ΔSPI-19 mutant, using VEX-Capture, complemented this colonization defect. In contrast, transfer of SPI-19 from Gallinarum to Enteritidis resulted in transient increase in the colonization of the ileum, liver and spleen at day 1 post-infection, but at days 3 and 5 post-infection a strong colonization defect of the gut and internal organs of the experimentally infected chickens was observed. Our data indicate that SPI-19 and the T6SS encoded in this region contribute to the colonization of the gastrointestinal tract and internal organs of chickens by Salmonella Gallinarum and suggest that degradation of SPI-19 T6SS in Salmonella Enteritidis conferred an advantage in colonization of the avian host. PMID:20661437

  10. Efficient Breeding by Genomic Mating.

    PubMed

    Akdemir, Deniz; Sánchez, Julio I

    2016-01-01

    Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population.

  11. Efficient Breeding by Genomic Mating

    PubMed Central

    Akdemir, Deniz; Sánchez, Julio I.

    2016-01-01

    Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population. PMID:27965707

  12. Molecular Epidemiology and Distribution of Serotypes, Surface Proteins, and Antibiotic Resistance among Group B Streptococci in Italy▿

    PubMed Central

    Gherardi, Giovanni; Imperi, Monica; Baldassarri, Lucilla; Pataracchia, Marco; Alfarone, Giovanna; Recchia, Simona; Orefici, Graziella; Dicuonzo, Giordano; Creti, Roberta

    2007-01-01

    Group B streptococci (GBS) comprising three different sets of isolates (31 invasive, 36 noninvasive, and 24 colonizing isolates) were collected in Italy during the years 2002 to 2005. Clonal groups were established by pulsed-field gel electrophoresis (PFGE), and selected isolates were studied by multilocus sequence typing (MLST). GBS isolates were also characterized by classical and molecular techniques for serotyping and protein gene and antibiotic resistance profiling. Some serotypes were significantly associated with a particular isolate population: serotype Ia more frequently corresponded to invasive strains than other strains, serotype V was more frequently encountered among noninvasive strains, and nontypeable strains were more common among isolates from carriers. Four major clonal groups accounted for 52.7% of all isolates: PFGE type 1/clonal complex 1 (CC1) comprised mainly serotype V isolates carrying the alp3 gene, PFGE type 2/CC23 encompassed serotype Ia isolates with the alp1 or alpha gene, PFGE type 3/CC17 comprised serotype III isolates carrying the rib gene, and PFGE type 4/CC19 consisted mainly of serotype II isolates possessing the rib gene. The same serotypes were shared by isolates of different clonal groups, and conversely, isolates belonging to the same clonal groups were found to be of different serotypes, presumably due to capsular switching by the horizontal transfer of capsular genes. Erythromycin resistance (prevalence, 16.5%; 15 resistant isolates of 91) was restricted to strains isolated from patients with noninvasive infections and carriers, while tetracycline resistance was evenly distributed (prevalence, 68.1%; 62 resistant isolates of 91). Most erythromycin-resistant GBS strains were of serotype V, were erm(B) positive, and belonged to the PFGE type 1/CC1 group, suggesting that macrolide resistance may have arisen both by clonal dissemination and by the horizontal transfer of resistance genes. PMID:17634303

  13. Mechanical seal having a double-tier mating ring

    SciTech Connect

    Khonsari, Michael M.; Somanchi, Anoop K.

    2005-09-13

    An apparatus and method to enhance the overall performance of mechanical seals in one of the following ways: by reducing seal face wear, by reducing the contact surface temperature, or by increasing the life span of mechanical seals. The apparatus is a mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) comprising a rotating ring and a double-tier mating ring. In a preferred embodiment, the double-tier mating ring comprises a first and a second stationary ring that together form an agitation-inducing, guided flow channel to allow for the removal of heat generated at the seal face of the mating ring by channeling a coolant entering the mating ring to a position adjacent to and in close proximity with the interior surface area of the seal face of the mating ring.

  14. Discrepancy between Penner serotyping and polymerase chain reaction fingerprinting of Campylobacter isolated from poultry and other animal sources.

    PubMed

    Aarts, H J; van Lith, L A; Jacobs-Reitsma, W F

    1995-06-01

    Thirty-four Campylobacter jejuni or coli strains, isolated from various livestock and darkling beetles from two Dutch poultry farms during different broiler production cycles, were subjected to Penner serotyping and polymerase chain reaction (PCR) fingerprint analysis. Ten different Penner serotypes were determined in the isolates. Visual scoring of the PCR fingerprints resulted in 14 clearly different profiles. Some strains with identical Penner serotypes exhibited different PCR fingerprints and conversely strains with different serotypes produced identical PCR fingerprints. Discrepancies between Penner serotyping and PCR fingerprinting were most obvious between isolates from different animal sources. Indications for the occurrence of genomic rearrangements were found. The inconsistency between serotyping and fingerprinting of Campylobacter strains suggests that conventional typing methods should be used in combination with fingerprinting if the epidemiological factors that contribute to Campylobacter colonization of live chickens are to be assessed reliably.

  15. Prevalence and Characteristics of Salmonella Serotypes Isolated from Fresh Produce Marketed in the United States.

    PubMed

    Reddy, Shanker P; Wang, Hua; Adams, Jennifer K; Feng, Peter C H

    2016-01-01

    Salmonella continues to rank as one of the most costly foodborne pathogens, and more illnesses are now associated with the consumption of fresh produce. The U.S. Department of Agriculture Microbiological Data Program (MDP) sampled select commodities of fresh fruit and vegetables and tested them for Salmonella, pathogenic Escherichia coli, and Listeria. The Salmonella strains isolated were further characterized by serotype, antimicrobial resistance, and pulsed-field gel electrophoresis profile. This article summarizes the Salmonella data collected by the MDP between 2002 and 2012. The results show that the rates of Salmonella prevalence ranged from absent to 0.34% in cilantro. A total of 152 isolates consisting of over 50 different serotypes were isolated from the various produce types, and the top five were Salmonella enterica serotype Cubana, S. enterica subspecies arizonae (subsp. IIIa) and diarizonae (subsp. IIIb), and S. enterica serotypes Newport, Javiana, and Infantis. Among these, Salmonella serotypes Newport and Javiana are also listed among the top five Salmonella serotypes that caused most foodborne outbreaks. Other serotypes that are frequent causes of infection, such as S. enterica serotypes Typhimurium and Enteritidis, were also found in fresh produce but were not prevalent. About 25% of the MDP samples were imported produce, including 65% of green onions, 44% of tomatoes, 42% of hot peppers, and 41% of cantaloupes. However, imported produce did not show higher numbers of Salmonella-positive samples, and in some products, like cilantro, all of the Salmonella isolates were from domestic samples. About 6.5% of the Salmonella isolates were resistant to the antimicrobial compounds tested, but no single commodity or serotype was found to be the most common carrier of resistant strains or of resistance. The pulsed-field gel electrophoresis profiles of the produce isolates showed similarities with Salmonella isolates from meat samples and from outbreaks, but

  16. Genetic and virulence-phenotype characterization of serotypes 2 and 9 of Streptococcus suis swine isolates.

    PubMed

    Blume, Verena; Luque, Inmaculada; Vela, Ana I; Borge, Carmen; Maldonado, Alfonso; Domínguez, Lucas; Tarradas, Carmen; Fernández-Garayzábal, José F

    2009-09-01

    The aim of this study was to analyze the genetic characteristics and virulence phenotypes of Streptococcus suis, specifically, in clinical isolates of serotypes 2 and 9 (n = 195), obtained from diverse geographical areas across Spain. Pulsed-field gel electrophoresis (PFGE) typing identified 97 genetic profiles, 68% of which were represented by single isolates, indicative of a substantial genetic diversity among the S. suis isolates analyzed. Five PFGE profiles accounted for 33.3% of the isolates and were isolated from 38% of the herds in nine different provinces, indicative of the bacterium's widespread distribution in the Spanish swine population. Representative isolates of the most prevalent PFGE profiles of both serotypes were subjected to multilocus sequence typing (MLST) analysis. The results indicated that serotypes 2 and 9 have distinct genetic backgrounds. Serotype 2 isolates belong to the ST1 complex, a highly successful clone that has spread over most European countries. In accordance with isolates of this complex, most serotype 2 isolates also expressed the phenotype MRP(+)EF(+)SLY(+). Serotype 9 isolates belong to the ST61 complex, which is distantly related to the widespread European ST87 clone. Also, in contrast to most isolates of the European ST87 clone, which express the large variant MRP*, the majority of serotype 9 isolates (97.9%) did not express the protein.

  17. Clonal dissemination of human isolates of Streptococcus suis serotype 14 in Thailand.

    PubMed

    Kerdsin, Anusak; Oishi, Kazunori; Sripakdee, Saowalak; Boonkerd, Nitsara; Polwichai, Pitimol; Nakamura, Shota; Uchida, Ryuichi; Sawanpanyalert, Pathom; Dejsirilert, Surang

    2009-11-01

    Most cases of Streptococcus suis infection in humans are caused by serotype 2 strains, and only a few cases caused by other serotypes have been reported. Among 177 human isolates of S. suis in Thailand, 12 (6.8 %) were identified as being of serotype 14, and an occurrence of sporadic S. suis serotype 14 infection was noted during 2006-2008, particularly in northern Thailand. Clinical presentations of the 12 patients (median age 62.9 years) included meningitis (58.3 %), septic arthritis (25 %) and sepsis (16.7 %). These clinical features were similar to those previously reported for S. suis infections, except that there were no fatal cases. All of the 12 serotype 14 strains belonged to the multilocus sequence types (ST) 105 (n=11) and the novel ST127 (n=1). Molecular typing by PFGE revealed four different pulsotypes, including an identical pattern for nine ST105 strains and three closely related patterns for two ST105 strains and one ST127 strain. Our PFGE data suggested clonal dissemination of ST105 strains in Thailand. Because serotype 14 is becoming a more common cause of S. suis infections in humans, diagnostic tests for serotype 14 should be performed in South-East Asian countries.

  18. Are mating strategies and mating tactics independent constructs?

    PubMed

    Allen, J Sabura; Bailey, Kent G

    2007-08-01

    This study explored the constructs of mating tactics and mating strategy. These constructs are conceptually related but distinct. In current research, the measurement of one of these constructs is often viewed as being indicative of the other. Therefore, an exploration of these constructs will enhance understanding of study outcomes in this research area. Self-report measures of mating tactics and strategies were administered to 183 female participants, aged 18-45 years. The Escalating Sexual Encounters Questionnaire (ESEQ, Greer & Buss, 1994), the Derogatis' Sexual Experience Scale (Derogatis & Melisaratos, 1979), the Sexual Strategies Measure (SSM, Schmitt, 1996), the Sociosexual Orientation Inventory (Simpson & Gangestad, 1991), and two questions assessing age at menarche and total number of sexual partners were administered. Exploratory factor analysis with oblique rotation produced two distinct factors reflecting a "tactic"-based factor and a "strategy"-based factor. This finding is consistent with viewing mating tactics and mating strategies as distinct and varying independently. An important implication of this study is that measurement of mating tactics is not indicative of underlying mating strategies in women. Further, four patterns of female mating style emerged upon review of participant factor scores and are discussed within an evolutionary context.

  19. Variation in mating systems of salamanders: mate guarding or territoriality?

    PubMed

    Deitloff, Jennifer; Alcorn, Michael A; Graham, Sean P

    2014-07-01

    Two of the most common mating tactics in vertebrates are mate guarding and territoriality, yet much of the research on these strategies has focused on mating systems in birds, despite novel insights gained from studying less traditional systems. North American stream salamanders that comprise the Eurycea bislineata complex represent an excellent nontraditional system for comparing mating strategies because these species exhibit a continuum of male morphologies, diverse habitat associations, and various potential mating strategies. We studied two species within this complex that exhibit the extremes of this continuum, Eurycea aquatica (robust morph) and Eurycea cirrigera (slender morph). The larger head in males of E. aquatica is due to larger musculature around the jaw and may be associated with aggressive behavior. Therefore, we hypothesized that the robust morphology exhibited by males of E. aquatica provides benefits during either territorial defense or mate defense and that males of E. cirrigera would not exhibit aggression in either scenario. We found that neither species exhibited aggressive behavior to defend a territory. However, in the presence of a female, males of E. aquatica were significantly more aggressive toward intruding males than were males of E. cirrigera. Therefore, mate-guarding behavior occurs in E. aquatica, and the enlarged head of males likely aids in deterring rivals. This is the first demonstration of mate-guarding behavior in a plethodontid, the most speciose family of salamanders.

  20. The Relevance of a Novel Quantitative Assay to Detect up to 40 Major Streptococcus pneumoniae Serotypes Directly in Clinical Nasopharyngeal and Blood Specimens

    PubMed Central

    Albrich, Werner C.; van der Linden, Mark P. G.; Bénet, Thomas; Chou, Monidarin; Sylla, Mariam; Barreto Costa, Patricia; Richard, Nathalie; Klugman, Keith P.; Endtz, Hubert P.; Paranhos-Baccalà, Gláucia; Telles, Jean-Noël

    2016-01-01

    For epidemiological and surveillance purposes, it is relevant to monitor the distribution and dynamics of Streptococcus pneumoniae serotypes. Conventional serotyping methods do not provide rapid or quantitative information on serotype loads. Quantitative serotyping may enable prediction of the invasiveness of a specific serotype compared to other serotypes carried. Here, we describe a novel, rapid multiplex real-time PCR assay for identification and quantification of the 40 most prevalent pneumococcal serotypes and the assay impacts in pneumonia specimens from emerging and developing countries. Eleven multiplex PCR to detect 40 serotypes or serogroups were optimized. Quantification was enabled by reference to standard dilutions of known bacterial load. Performance of the assay was evaluated to specifically type and quantify S. pneumoniae in nasopharyngeal and blood samples from adult and pediatric patients hospitalized with pneumonia (n = 664) from five different countries. Serogroup 6 was widely represented in nasopharyngeal specimens from all five cohorts. The most frequent serotypes in the French, South African, and Brazilian cohorts were 1 and 7A/F, 3 and 19F, and 14, respectively. When both samples were available, the serotype in blood was always present as carriage with other serotypes in the nasopharynx. Moreover, the ability of a serotype to invade the bloodstream may be linked to its nasopharyngeal load. The mean nasopharyngeal concentration of the serotypes that moved to the blood was 3 log-fold higher than the ones only found in the nasopharynx. This novel, rapid, quantitative assay may potentially predict some of the S. pneumoniae serotypes invasiveness and assessment of pneumococcal serotype distribution. PMID:26986831

  1. Serotype b of Aggregatibacter actinomycetemcomitans increases osteoclast and memory T-lymphocyte activation.

    PubMed

    Melgar-Rodríguez, S; Díaz-Zúñiga, J; Alvarez, C; Rojas, L; Monasterio, G; Carvajal, P; Escobar, A; Sanz, M; Vernal, R

    2016-04-01

    During periodontitis, alveolar bone resorption is associated with activation of T helper type 17 (Th17) lymphocytes and receptor activator of nuclear factor-κB ligand (RANKL) -induced osteoclasts. We previously reported that serotype b of Aggregatibacter actinomycetemcomitans has a higher capacity to trigger Th17-type differentiation and function in activated T lymphocytes and its lipopolysaccharide is a more potent immunogen compared with the other serotypes. This study aimed to investigate whether serotype b of A. actinomycetemcomitans induces higher Th17-associated RANKL production, RANKL-induced osteoclast activation, and antigen-specific memory T lymphocyte proliferation. On naive CD4(+) T lymphocytes stimulated with autologous dendritic cells primed with different A. actinomycetemcomitans serotypes, RANKL production, T-bet, GATA-3, RORC2 and Foxp3 expression, RORC2/RANKL intracellular double-expression, TRAP(+) osteoclast activation, and bone resorption were quantified. The frequency of proliferating memory T lymphocytes in response to A. actinomycetemcomitans serotypes was determined in periodontitis and healthy subjects. Naive CD4(+) T lymphocytes stimulated by serotype b-primed dendritic cells elicited higher levels of RANKL, RORC2, TRAP(+) osteoclasts, and bone resorption than the same cells stimulated with the other serotypes. RANKL positively correlated and co-expressed with RORC2. Memory T lymphocytes responding to serotype b were more frequently detected in periodontitis patients than healthy subjects. These results indicate that serotype b of A. actinomycetemcomitans is associated with higher production of RANKL and these increased levels are associated with Th17 lymphocyte induction, osteoclast activation, and bone resorption.

  2. Male-male interactions and mating kinetics in Drosophila.

    PubMed

    Wallace, B

    1990-05-01

    Male-male interaction (K) has been estimated from data on the attrition rate of virgin females per minute in a study of the mating kinetics in Drosophila. K is expressed as the time males expend on other males relative to that expended while searching for, courting, and copulating with females. The value of K in these studies ranged from 0 (approximately) to .695; it was affected both by strain (sepia or ebony D. melanogaster and wild-type D. simulans) and by size of the mating chamber. Host-parasitoid models of ecologists appear to be appropriate for examining mating kinetics in Drosophila.

  3. Positive assortative mating between recently described sympatric morphs of Icelandic sticklebacks

    PubMed Central

    Ólafsdóttir, Gudbjörg Á; Ritchie, Michael G; Snorrason, Sigurdur S

    2006-01-01

    Recently, models of sympatric speciation have suggested that assortative mating can develop between sympatric morphs due to divergence in an ecologically important character. For example, in sympatric pairs of threespine stickleback (Gasterosteus aculeatus L.) size-assortative mating seems to be instrumental in reproductive isolation. Here, we examine courtship behaviour and assortative mating of newly described sympatric stickleback morphs in Lake Thingvallavatn, Iceland. We find that the two morphs show strong positive assortative mating. However, the mechanism involved in mate choice does not seem to be as straightforward as in other similar systems of sympatric stickleback morphs and may involve variation in nest type. PMID:17148375

  4. Mating programs including genomic relationships

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Computer mating programs have helped breeders minimize pedigree inbreeding and avoid recessive defects by mating animals with parents that have fewer common ancestors. With genomic selection, breed associations, AI organizations, and on-farm software providers could use new programs to minimize geno...

  5. Mating with large males decreases the immune defence of females in Drosophila melanogaster.

    PubMed

    Imroze, K; Prasad, N G

    2011-12-01

    Mating has been widely reported to be a costly event for females. Studies indicate that female cost of mating in terms of fecundity and survivorship can be affected by their mates, leading to antagonistic coevolution between the sexes. However, as of now, there is no evidence that the female cost of mating in terms of immune defence is affected by their mates. We assess the effect of different sized males on antibacterial immune defence and reproductive fitness of their mates. We used a large outbred population of Drososphila melanogaster as the host and Serratia marcescens as the pathogen. We generated three different male phenotypes: small, medium and large, by manipulating larval densities. Compared to females mating with small males, those mating with large males had higher bacterial loads and lower fecundity. There was no significant effect of male phenotype on the fraction of females mated or copulation duration (an indicator of ejaculate investment). Thus, our study is the first clear demonstration that male phenotype can affect the cost of mating to females in terms of their antibacterial immune defence. Mating with large males imposes an additional cost of mating to females in terms of reduced immune defence. The observed results are very likely due to qualitative/quantitative differences in the ejaculates of the three different types of males. If the phenotypic variation that we observed in males in our study is mirrored by genetic variation, then, it can potentially lead to antagonistic coevolution of the sexes over immune defence.

  6. Assortative mating without assortative preference.

    PubMed

    Xie, Yu; Cheng, Siwei; Zhou, Xiang

    2015-05-12

    Assortative mating--marriage of a man and a woman with similar social characteristics--is a commonly observed phenomenon. In the existing literature in both sociology and economics, this phenomenon has mainly been attributed to individuals' conscious preferences for assortative mating. In this paper, we show that patterns of assortative mating may arise from another structural source even if individuals do not have assortative preferences or possess complementary attributes: dynamic processes of marriages in a closed system. For a given cohort of youth in a finite population, as the percentage of married persons increases, unmarried persons who newly enter marriage are systematically different from those who married earlier, giving rise to the phenomenon of assortative mating. We use microsimulation methods to illustrate this dynamic process, using first the conventional deterministic Gale-Shapley model, then a probabilistic Gale-Shapley model, and then two versions of the encounter mating model.

  7. You Mate, I Mate: Macaque Females Synchronize Sex not Cycles

    PubMed Central

    Fürtbauer, Ines; Mundry, Roger; Heistermann, Michael; Schülke, Oliver; Ostner, Julia

    2011-01-01

    Extended female sexuality in species living in multimale-multifemale groups appears to enhance benefits from multiple males. Mating with many males, however, requires a low female monopolizability, which is affected by the spatiotemporal distribution of receptive females. Ovarian cycle synchrony potentially promotes overlapping receptivity if fertile and receptive periods are tightly linked. In primates, however, mating is often decoupled from hormonal control, hence reducing the need for synchronizing ovarian events. Here, we test the alternative hypothesis that females behaviorally coordinate their receptivity while simultaneously investigating ovarian cycle synchrony in wild, seasonal Assamese macaques (Macaca assamensis), a promiscuous species with extremely extended female sexuality. Using fecal hormone analysis to assess ovarian activity we show that fertile phases are randomly distributed, and that dyadic spatial proximity does not affect their distribution. We present evidence for mating synchrony, i.e., the occurrence of the females' receptivity was significantly associated with the proportion of other females mating on a given day. Our results suggest social facilitation of mating synchrony, which explains (i) the high number of simultaneously receptive females, and (ii) the low male mating skew in this species. Active mating synchronization may serve to enhance the benefits of extended female sexuality, and may proximately explain its patterning and maintenance. PMID:22022541

  8. Female Stick Insects Mate Multiply to Find Compatible Mates.

    PubMed

    Arbuthnott, Devin; Crespi, Bernard J; Schwander, Tanja

    2015-10-01

    Why females of many species mate multiply in the absence of direct benefits remains an open question in evolutionary ecology. Interacting and mating with multiple males can be costly to females in terms of time, resources, predation risk, and disease transmission. A number of indirect genetic benefits have been proposed to explain such behaviors, but the relative importance of these mechanisms in natural systems remains unclear. We tested for several direct and indirect benefits of polyandry in the walking stick Timema cristinae. We found no evidence of direct benefits with respect to longevity or fecundity. However, male × female genotypic interactions affected egg-hatching success and offspring production independent of relatedness, suggesting that mating with certain males benefits females and that the best male may differ for each female. Furthermore, multiply mated females biased paternity toward one or few males, and the extent of this bias was positively correlated to egg-hatching success. Our data, therefore, provide evidence for indirect benefits through compatibility effects in this species. By mating multiply, females may improve their chances of mating with a compatible male if compatibility cannot be assessed before mating. Such compatibility effects can explain the evolution and maintenance of polyandry in Timema and many other species.

  9. Truncated surface protective antigen (SpaA) of Erysipelothrix rhusiopathiae serotype 1a elicits protection against challenge with serotypes 1a and 2b in pigs.

    PubMed

    Imada, Y; Goji, N; Ishikawa, H; Kishima, M; Sekizaki, T

    1999-09-01

    Erysipelothrix rhusiopathiae is a causal agent of swine erysipelas, which is of economic importance in the swine industry by virtue of causing acute septicemia, chronic arthritis, and endocarditis. However, little is known about the genetic properties of its protective antigens. Recently, a surface protective antigen (SpaA) gene was identified from serotype 2 in a mouse model. We cloned spaA from virulent strain Fujisawa (serotype 1a) and determined that the N-terminal 342 amino acids without C-terminal repeats of 20 amino acids have the ability to elicit protection in mice. Fusions of 342 amino acids of Fujisawa SpaA and histidine hexamer (HisSpa1.0) protected pigs against challenge with both serotype 1 and serotype 2, the most important serotypes in the swine industry. Pigs immunized with HisSpa1.0 reacted well with both HisSpa1.0 and intact SpaA by enzyme-linked immunosorbent assay and immunoblotting. Serum collected at the time of challenge from a pig immunized with HisSpa1. 0 markedly enhanced the in vitro phagocytic and killing activity of pig neutrophils against the bacteria. DNA sequences of protective regions of spaA genes from five strains of serotypes 1 and 2 were almost identical. The full DNA sequences also seemed to be conserved among strains of all 12 serotype reference strains harboring the spaA gene by restriction fragment length polymorphism analysis of PCR products. These results indicates that SpaA is a common protective antigen of serotypes 1 and 2 of E. rhusiopathiae in swine and will be a useful tool for development of new types of vaccines and diagnostic tools for effective control of the disease.

  10. Evolution of mate-choice imprinting: competing strategies.

    PubMed

    Tramm, Nora A; Servedio, Maria R

    2008-08-01

    Mate-choice imprinting, the determination of mating preferences at an early age based on an individual's observation of adults, plays a role in mate choice in a wide variety of animals. Theoretical work has thus far been focused either on the effects of mate-choice imprinting on the evolution of the male trait used as a mating cue, or on the evolution of imprinting against a nonimprinting background. We ask the question: if multiple types of imprinting are possible in a species, which is likely to evolve? We develop a haploid population genetic model to compare the evolution of three forms of imprinting: paternal, maternal, and oblique (nonparental adult) imprinting. We find that paternal imprinting is the most likely to evolve, whereas maternal and oblique are nearly equivalent. We identify two factors that determine a strategy's success: its "imprinting set," the set of individuals imprinted upon, and phenogenotypic disequilibrium, the association between imprinted preferences and mating cues. We assess the predictive power of these factors, and find that the imprinting set is the primary determinant of a strategy's success. We suggest that the imprinting set concept may be generalized to predict the success of additional imprinting strategies, such as mate-choice copying.

  11. Model of Exploratory Search for Mating Partners by Fission Yeast

    NASA Astrophysics Data System (ADS)

    Hurwitz, Daniel; Bendezu, Felipe; Martin, Sophie; Vavylonis, Dimitrios

    2014-03-01

    During conditions of nitrogen starvation, the model eukaryote S. pombe (fission yeast) undergoes sexual sporulation. Because fission yeast are non-motile, contact between opposite mating types during spore formation is accomplished by polarizing growth, via the Rho GTP-ase Cdc42, in each mating type towards the selected mate, a process known as shmooing. Recent findings showed that cells pick one of their neighboring compatible mates by randomizing the position of the Cdc42 complex about the cell membrane, such that the complex is stabilized near areas of high concentration of the opposite mating type pheromone. We developed Monte Carlo simulations to model partner finding in populations of mating cells and in small cell clusters. We assume that pheromones are secreted at the site of Cdc42 accumulation and that the Cdc42 dwell time increases in response to increasing pheromone concentration. We measured the number of cells that succeed in successful reciprocal pairing, the number of cells that were unable to find a partner, and the number of cells that picked a partner already engaged with another cell. For optimal cell pairing, we find the pheromone concentration decay length is around 1 micron, of order the cell size. We show that non-linear response of Cdc42 dwell time to pheromone concentration improves the number of successful pairs for a given spatial cell distribution. We discuss how these results compare to non-exploratory pairing mechanisms.

  12. Assortative mating by diet in a phenotypically unimodal but ecologically variable population of stickleback.

    PubMed

    Snowberg, Lisa K; Bolnick, Daniel I

    2008-11-01

    Speciation with gene flow may be driven by a combination of positive assortative mating and disruptive selection, particularly if selection and assortative mating act on the same trait, eliminating recombination between ecotype and mating type. Phenotypically unimodal populations of threespine stickleback (Gasterosteus aculeatus) are commonly subject to disruptive selection due to competition for alternate prey. Here we present evidence that stickleback also exhibit assortative mating by diet. Among-individual diet variation leads to variation in stable isotopes, which reflect prey use. We find a significant correlation between the isotopes of males and eggs within their nests. Because egg isotopes are derived from females, this correlation reflects assortative mating between males and females by diet. In concert with disruptive selection, this assortative mating should facilitate divergence. However, the stickleback population remains phenotypically unimodal, highlighting the fact that assortative mating and disruptive selection do not guarantee evolutionary divergence and speciation.

  13. Diversity of rotavirus serotypes in Mexican infants with gastroenteritis.

    PubMed Central

    Padilla-Noriega, L; Arias, C F; López, S; Puerto, F; Snodgrass, D R; Taniguchi, K; Greenberg, H B

    1990-01-01

    One hundred thirty-two stool specimens from infants with rotavirus gastroenteritis hospitalized in two Mexican cities (Mexico City and Mérida) were examined by serotype- and subgroup-specific enzyme immunoassays. Among them, 38 (29%) were serotype 1, 15 (11%) were serotype 2, 13 (10%) were serotype 3, 22 (17%) were serotype 4, none was serotype 5 or 6, and 44 (33%) could not be serotyped. By subgrouping, 121 specimens were characterized as follows: 24 (18%) were subgroup 1, 97 (74%) were subgroup 2, and none had both subgroup specificities. While serotype 1 rotavirus predominated in the Mexico City area for 4 consecutive years (1984 to 1987), serotype 4 predominated in Mérida during the single epidemic season studied (1985). These data demonstrate that all four primary human rotavirus serotypes circulated in Mexico, with serotype 1 being the most prevalent. The seroneutralization responses of 14 of the 22 patients infected with serotype 4 strains had been previously studied. Of these 14 infants, 11 appeared to have primary infections, as indicated by absence of neutralizing antibodies in the acute-phase sera and their young age (8 months on average) at the time of illness. Seven patients seroresponded to serotypes 1 and 4; two seroresponded to serotypes 1, 3, and 4; three seroresponded to serotype 1; and two had low-level seroresponses to serotype 3 or 4. These data indicate that heterotypic neutralizing antibody responses occur frequently following infection with serotype 4 rotaviruses. PMID:2166073

  14. [The comparative characteristics of the Salmonella serotypes rarely encountered in the Maritime Territory].

    PubMed

    Koval'chuk, N I; Shubin, F N; Khoroshko, V A; Sheverdina, F N; Tarasenko, T T; Kosheleva, N G

    1997-01-01

    The results of the comparative study of the phenotypical properties and the plasmid profile of 63 strains of salmonellae, belonging to 44 serotypes of groups B, C1, C2, C3, D, E1, E4, F. The study revealed that strains of different serotypes had their individual plasmid profile. Strains of the same serotype of salmonellae isolated from similar sources had an identical plasmid profile, while strains isolated from different sources differed in their plasmid profiles, though they might have a similar phenotype. Plasmid analysis was shown to be an effective method for the intraspecific typing of rarely isolated Salmonella serotypes and suitable for use as the basis of the microbiological monitoring of salmonellae.

  15. Different cognitive processes underlie human mate choices and mate preferences.

    PubMed

    Todd, Peter M; Penke, Lars; Fasolo, Barbara; Lenton, Alison P

    2007-09-18

    Based on undergraduates' self-reports of mate preferences for various traits and self-perceptions of their own levels on those traits, Buston and Emlen [Buston PM, Emlen ST (2003) Proc Natl Acad Sci USA 100:8805-8810] concluded that modern human mate choices do not reflect predictions of tradeoffs from evolutionary theory but instead follow a "likes-attract" pattern, where people choose mates who match their self-perceptions. However, reported preferences need not correspond to actual mate choices, which are more relevant from an evolutionary perspective. In a study of 46 adults participating in a speed-dating event, we were largely able to replicate Buston and Emlen's self-report results in a pre-event questionnaire, but we found that the stated preferences did not predict actual choices made during the speed-dates. Instead, men chose women based on their physical attractiveness, whereas women, who were generally much more discriminating than men, chose men whose overall desirability as a mate matched the women's self-perceived physical attractiveness. Unlike the cognitive processes that Buston and Emlen inferred from self-reports, this pattern of results from actual mate choices is very much in line with the evolutionary predictions of parental investment theory.

  16. Assortative mating counteracts the evolution of dispersal polymorphisms.

    PubMed

    Fronhofer, Emanuel A; Kubisch, Alexander; Hovestadt, Thomas; Poethke, Hans-Joachim

    2011-09-01

    Polymorphic dispersal strategies are found in many plant and animal species. An important question is how the genetic variation underlying such polymorphisms is maintained. Numerous mechanisms have been discussed, including kin competition or frequency-dependent selection. In the context of sympatric speciation events, genetic and phenotypic variation is often assumed to be preserved by assortative mating. Thus, recently, this has been advocated as a possible mechanism leading to the evolution of dispersal polymorphisms. Here, we examine the role of assortative mating for the evolution of trade-off-driven dispersal polymorphisms by modeling univoltine insect species in a metapopulation. We show that assortative mating does not favor the evolution of polymorphisms. On the contrary, assortative mating favors the evolution of an intermediate dispersal type and a uni-modal distribution of traits within populations. As an alternative, mechanism dominance may explain the occurrence of two discrete morphs.

  17. Risk of death from pneumococcal pneumonia is a stable serotype-associated property: a meta-analysis

    PubMed Central

    Weinberger, Daniel M.; Harboe, Zitta B.; Sanders, Elisabeth A.M.; Ndiritu, Moses; Klugman, Keith P.; Rückinger, Simon; Dagan, Ron; Adegbola, Richard; Cutts, Felicity; Johnson, Hope L.; O’Brien, Katherine L.; Scott, J. Anthony; Lipsitch, Marc

    2010-01-01

    Background The 92 capsular serotypes of Streptococcus pneumoniae differ greatly in nasopharyngeal carriage prevalence, invasiveness and disease incidence. There has been some debate, though, as to whether serotype independently affects the outcome of invasive pneumococcal disease (IPD). Published studies have shown variable results with regards to case-fatality ratios for specific serotypes and the role of host factors in affecting these relationships. We evaluated whether risk of death from IPD is a stable serotype-associated property across studies, and then compared the pooled effect estimates with epidemiologic and biological correlates. Methods We performed a systematic review and meta-analysis of serotype-specific disease outcome for pneumonia and meningitis cases. Study-specific estimates of risk of death (risk ratio, RR) were pooled from 9 studies that provided serotype-specific data on pneumonia and meningitis using a random-effects method with serotype 14 as the reference. Pooled RRs were compared to RRs from adult cases with low co-morbidity scores to evaluate potential confounding by host factors. Results There were significant differences in the RR estimates between serotypes among bacteremic pneumonia cases. Overall, types 1, 7F and 8 were associated with decreased RRs and types 3, 6A, 6B, 9N and 19F were associated with increased RRs. Outcomes among meningitis cases did not differ significantly between types. Serotypes with increased RRs tended to have a high carriage prevalence, low invasiveness, and were more heavily encapsulated in vitro. These results suggest that IPD outcome, like other epidemiologic measures, is a stable serotype-associated property. PMID:20715907

  18. The cps locus of Streptococcus suis serotype 16: development of a serotype-specific PCR assay.

    PubMed

    Wang, Kaicheng; Fan, Weixing; Wisselink, Henk; Lu, Chengping

    2011-12-15

    Streptococcus suis serotype 16 can infect pigs and humans. We describe the identification and the characterization of the capsular polysaccharides synthesis locus of S. suis serotype 16. Using PCR primers flanking the capsular polysaccharides synthesis locus, a 30,101-bp fragment was amplified. Twenty-nine open reading frames related to transcriptional regulation, glycosyl transfer, oligosaccharide repeat unit polymerization, polysaccharide transport, sialic acid synthesis and modification were identified. The data suggests that the serotype 16 capsule is synthesized by a Wzy-dependent pathway. So far, no rapid and sensitive diagnostic method is available for detection of serotype 16 isolates. A serotype specific PCR test for the rapid and sensitive detection of S. suis serotype 16 was developed. Cross hybridization experiments of individual cps genes with chromosomal DNAs of 33 serotypes showed that the cps16G and cps16K genes hybridized with serotype 16 only. Primers based on cps16G were used to develop a serotype 16 specific PCR. The PCR assay was successfully used to identify S. suis serotype 16 in the 99 Chinese S. suis clinical isolates and 8 European isolates.

  19. Evaluation of cross-protection of bluetongue virus serotype 4 with other serotypes in sheep.

    PubMed

    Zulu, Gcwalisile B; Venter, Estelle H

    2014-10-16

    Bluetongue (BT) is a non-contagious disease of sheep and other domestic and wild ruminants caused by the bluetongue virus (BTV). Currently 26 serotypes of the virus have been identified. In South Africa, 22 serotypes have been identified and BT is controlled mainly by annual vaccinations using a freeze-dried live attenuated polyvalent BTV vaccine. The vaccine is constituted of 15 BTV serotypes divided into three separate bottles and the aim is to develop a vaccine using fewer serotypes without compromising the immunity against the disease. This study is based on previously reported cross-neutralisation of specific BTV serotypes in in vitro studies. Bluetongue virus serotype 4 was selected for this trial and was tested for cross-protection against serotype 4 (control), 1 (unrelated serotype), 9, 10 and 11 in sheep using the serum neutralisation test. The purpose of the study was to determine possible cross-protection of different serotypes in sheep. Of those vaccinated with BTV-4 and challenged with BTV-1, which is not directly related to BTV-4, 20% were completely protected and 80% showed clinical signs, but the reaction was not as severe as amongst the unvaccinated animals. In the group challenged with BTV-10, some showed good protection and some became very sick. Those challenged with BTV-9 and BTV-11 had good protection. The results showed that BTV-4 does not only elicit a specific immune response but can also protect against other serotypes.

  20. Female extrapair mate choice in a cooperative breeder: trading sex for help and increasing offspring heterozygosity

    PubMed Central

    Rubenstein, Dustin R

    2007-01-01

    Sexual conflict between males and females over mating is common. Females that copulate with extrapair mates outside the pair-bond may gain (i) direct benefits such as resources or increased paternal care, (ii) indirect genetic benefits for their offspring, or (iii) insurance against infertility in their own social mate. Few studies have been able to demonstrate the different contexts in which females receive varying types of benefits from extrapair mates. Here, I examined sexual conflict, female extrapair mate choice, and patterns of extrapair paternity in the cooperatively breeding superb starling Lamprotornis superbus using microsatellite markers. Although extrapair paternity was lower than many other avian cooperative breeders (14% of offspring and 25% of nests), females exhibited two distinct mating patterns: half of the extrapair fertilizations were with males from inside the group, whereas half were with males from outside the group. Females with few potential helpers copulated with extrapair mates from within their group and thereby gained direct benefits in the form of additional helpers at the nest, whereas females paired to mates that were relatively less heterozygous than themselves copulated with extrapair mates from outside the group and thereby gained indirect genetic benefits in the form of increased offspring heterozygosity. Females did not appear to gain fertility insurance from copulating with extrapair mates. This is the first study to show that individuals from the same population mate with extrapair males and gain both direct and indirect benefits, but that they do so in different contexts. PMID:17526455

  1. Antimicrobial resistance and serotype prevalence of Salmonella isolated from dairy cattle in the southwestern United States.

    PubMed

    Edrington, T S; Schultz, C L; Bischoff, K M; Callaway, T R; Looper, M L; Genovese, K J; Jung, Y S; McReynolds, J L; Anderson, R C; Nisbet, D J

    2004-01-01

    Mature dairy cattle were sampled over a 2-year period (2001-2002) on six farms in New Mexico and Texas. Fecal samples (n = 1560) were collected via rectal palpation and cultured for Salmonella, and one isolate from each positive sample was serotyped. Three isolates of each serotype, with the exception of Salmonella Newport (n = 12), were examined for susceptibility to 17 antimicrobial agents. Twenty-two different serotypes were identified from a total of 393 Salmonella isolates. Montevideo was the predominant serotype (27%) followed by Mbandaka (15%), Senftenberg (11.4%), Newport (6.4%), Anatum (4.8%), and Give (4.8%). Salmonella Typhimurium and Dublin, two frequently reported serotypes, accounted for only 1% of the observed serotypes in this study. Sixty-four percent of the serotypes were susceptible to all 17 antimicrobials, 14% were resistant to a single agent, and 22% were multiresistant (2-11 types of resistance). All isolates tested were susceptible to amikacin, apramycin, imipenem, ceftriaxone, nalidixic acid, and ciprofloxacin. The most frequent types of resistance were to sulfamethoxazole, tetracycline, streptomycin, kanamycin, chloramphenicol, and ampicillin (ranging from 8.9 to 22.4%). Serotypes demonstrating multiple resistance included Dublin and Give (resistant to three or more antibiotics), Typhimurium (resistant to five antibiotics), and Newport (four and two isolates resistant to six and nine antibiotics, respectively). Class 1 integrons were present in only two Salmonella Dublin isolates and one Salmonella Newport isolate. The most prevalent resistance patterns observed in this study were toward antimicrobial agents commonly used in cattle, while all Salmonella isolates were susceptible to ceftriaxone and ciprofloxacin, antibiotics used in human medicine.

  2. Emergence of Multidrug-Resistant Pneumococcal Serotype 35B among Children in the United States.

    PubMed

    Olarte, Liset; Kaplan, Sheldon L; Barson, William J; Romero, José R; Lin, Philana Ling; Tan, Tina Q; Hoffman, Jill A; Bradley, John S; Givner, Laurence B; Mason, Edward O; Hultén, Kristina G

    2017-03-01

    Streptococcus pneumoniae serotype 35B is a nonvaccine serotype associated with high rates of penicillin nonsusceptibility. An increase in the proportion of multidrug-resistant (MDR) 35B isolates has recently been reported. The genetic events contributing to the emergence of MDR serotype 35B are unknown. The sequence type (ST) composition of 78 serotype 35B isolates obtained from pediatric patients with invasive pneumococcal disease from 1994 to 2014 and 48 isolates from pediatric patients with otitis media (noninvasive) from 2011 to 2014 was characterized by multilocus sequence typing (MLST). The most common STs were ST558 (69.2%), ST156 (10.3%), and ST452 (3.8%). Two major clonal complexes (CC), CC558 and CC156, were identified by eBURST analysis. Overall, 91% (71/78) of isolates were penicillin nonsusceptible and 16.7% (13/78) were MDR. Among all invasive serotype 35B isolates, MDR isolates increased significantly, from 2.9% (1/35) to 27.9% (12/43) (P = 0.004), after the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced. All CC156 isolates were identified after the introduction of PCV13 (0/35 [0%] before versus 9/43 [20.9%] after; P = 0.003) and were MDR. All CC156 isolates had similar antimicrobial susceptibility patterns; in contrast, high variability in antimicrobial susceptibility was observed among CC558 isolates. The distributions of CC558 and CC156 among invasive and noninvasive isolates were not different. The increased prevalence of MDR serotype 35B after the introduction of PCV13 was directly associated with the emergence of ST156. Genotyping suggests that capsular switching has occurred between MDR vaccine serotypes belonging to ST156 (e.g., 9V, 14, and 19A) and serotype 35B.

  3. Vibrio parahaemolyticus Strains of Pandemic Serotypes Identified from Clinical and Environmental Samples from Jiangsu, China

    PubMed Central

    Li, Jingjiao; Xue, Feng; Yang, Zhenquan; Zhang, Xiaoping; Zeng, Dexin; Chao, Guoxiang; Jiang, Yuan; Li, Baoguang

    2016-01-01

    Vibrio parahaemolyticus has emerged as a major foodborne pathogen in China, Japan, Thailand, and other Asian countries. In this study, 72 strains of V. parahaemolyticus were isolated from clinical and environmental samples between 2006 and 2014 in Jiangsu, China. The serotypes and six virulence genes including thermostable direct hemolysin (TDR) and TDR-related hemolysin (TRH) genes were assessed among the isolates. Twenty five serotypes were identified and O3:K6 was one of the dominant serotypes. The genetic diversity was assessed by multilocus sequence typing (MLST) analysis, and 48 sequence types (STs) were found, suggesting this V. parahaemolyticus group is widely dispersed and undergoing rapid evolution. A total of 25 strains of pandemic serotypes such as O3:K6, O5:K17, and O1:KUT were identified. It is worth noting that the pandemic serotypes were not exclusively identified from clinical samples, rather, nine strains were also isolated from environmental samples; and some of these strains harbored several virulence genes, which may render those strains pathogenicity potential. Therefore, the emergence of these “environmental” pandemic V. parahaemolyticus strains may poses a new threat to the public health in China. Furthermore, six novel serotypes and 34 novel STs were identified among the 72 isolates, indicating that V. parahaemolyticus were widely distributed and fast evolving in the environment in Jiangsu, China. The findings of this study provide new insight into the phylogenic relationship between V. parahaemolyticus strains of pandemic serotypes from clinical and environmental sources and enhance the MLST database; and our proposed possible O- and K- antigen evolving paths of V. parahaemolyticus may help understand how the serotypes of this dispersed bacterial population evolve. PMID:27303379

  4. Emergence of Neoteric Serotypes Among Multidrug Resistant Strains of Streptococcus pneumoniae Prevalent in Egypt

    PubMed Central

    Bahy, Rehab H; Hamouda, Hayam M; Shahat, Amal S; Yassin, Aymen S; Amin, Magdy A

    2016-01-01

    Background Streptococcus pneumoniae is still one of the major causes of morbidity and mortality worldwide. The prevalent serotype distribution had shown variation along different studies conducted at different time intervals. In order to efficiently assess the epidemiology of the diseases for effective preventive and treatment strategies, serotype prevalence need to be periodically reassessed. Objectives Conducting a reassessment of the prevalent S. pneumoniae serotypes in Egypt as an essential step in the search for a regional vaccine. In addition, monitoring the antibiotic susceptibility patterns of pneumococcal strains currently causing infections as an evaluation of therapeutic strategies applied. Materials and Methods A total of 100 specimens of different sources were collected in Cairo, Egypt, from 2011 to 2013, representing almost all different types of diseases caused by S. pneumoniae such as meningitis, pneumonia, otitis media and sinusitis. Conventional and molecular identification methods were performed, the antimicrobial susceptibility patterns were assessed and serotyping was done using PCR assays to identify the most prevalent types. In addition, detection of certain virulence genes for the most prevalent serotypes was carried out. Results Our results revealed that in Egypt, currently, the most prevalent serotypes were serogroup 6 and serotype 19F as they represented 58% of all isolates. High rates of resistance were found to different antibiotic classes. The lytA and psaA genes were found to be more sensitive for S. pneumoniae identification than ply. Conclusions Our study illustrates the importance of constantly monitoring the prevalent serotypes in any region in order to aid in the development of more effective vaccines. PMID:27303614

  5. Assortative mating without assortative preference

    PubMed Central

    Xie, Yu; Cheng, Siwei; Zhou, Xiang

    2015-01-01

    Assortative mating—marriage of a man and a woman with similar social characteristics—is a commonly observed phenomenon. In the existing literature in both sociology and economics, this phenomenon has mainly been attributed to individuals’ conscious preferences for assortative mating. In this paper, we show that patterns of assortative mating may arise from another structural source even if individuals do not have assortative preferences or possess complementary attributes: dynamic processes of marriages in a closed system. For a given cohort of youth in a finite population, as the percentage of married persons increases, unmarried persons who newly enter marriage are systematically different from those who married earlier, giving rise to the phenomenon of assortative mating. We use microsimulation methods to illustrate this dynamic process, using first the conventional deterministic Gale–Shapley model, then a probabilistic Gale–Shapley model, and then two versions of the encounter mating model. PMID:25918366

  6. Dengue viruses cluster antigenically but not as discrete serotypes

    PubMed Central

    Katzelnick, Leah C.; Fonville, Judith M.; Gromowski, Gregory D.; Arriaga, Jose Bustos; Green, Angela; James, Sarah L.; Lau, Louis; Montoya, Magelda; Wang, Chunling; VanBlargan, Laura A.; Russell, Colin A.; Thu, Hlaing Myat; Pierson, Theodore C.; Buchy, Philippe; Aaskov, John G.; Muñoz-Jordán, Jorge L.; Vasilakis, Nikos; Gibbons, Robert V.; Tesh, Robert B.; Osterhaus, Albert D.M.E.; Fouchier, Ron A.M.; Durbin, Anna; Simmons, Cameron P.; Holmes, Edward C.; Harris, Eva; Whitehead, Stephen S.; Smith, Derek J.

    2016-01-01

    The four genetically divergent dengue virus (DENV) types are traditionally classified as serotypes. Antigenic and genetic differences among the DENV types influence disease outcome, vaccine-induced protection, epidemic magnitude, and viral evolution. We characterized antigenic diversity in the DENV types by antigenic maps constructed from neutralizing antibody titers obtained from African green monkeys and after human vaccination and natural infections. Genetically, geographically, and temporally, diverse DENV isolates clustered loosely by type, but we found many are as similar antigenically to a virus of a different type as to some viruses of the same type. Primary infection antisera did not neutralize all viruses of the same DENV type any better than other types did up to two years after infection and did not show improved neutralization to homologous type isolates. That the canonical DENV types are not antigenically homogenous has implications for vaccination and research on the dynamics of immunity, disease, and the evolution of DENV. PMID:26383952

  7. Detection of four adenovirus serotypes within water-isolated strains of Acanthamoeba in the Canary Islands, Spain.

    PubMed

    Lorenzo-Morales, Jacob; Coronado-Alvarez, Nieves; Martínez-Carretero, Enrique; Maciver, Sutherland K; Valladares, Basilio

    2007-10-01

    We surveyed 236 potentially pathogenic Acanthamoeba strains, isolated from water sources in the Canary Islands, for the presence of human adenoviruses (HAdV) using a polymerase chain reaction (PCR)-based typing assay. A total of 34 of these strains were found to be positive for adenovirus belonging to four different HAdV serotypes (HAdV-1, 2, 8, and 37). We found that HAdV-2 was the most frequently encountered serotype amongst the Acanthamoeba strains, and their identification was confirmed by a nested PCR specific for this serotype. We showed that Acanthamoeba genotype T4 was highly associated with serotype HAdV-2, whereas Acanthamoeba genotype T3 was most often associated with adenovirus serotypes related to ocular diseases. Based on these data, we suggest that Acanthamoeba should be considered as a potential reservoir and perhaps even a transmitter of adenoviruses to human and other secondary hosts.

  8. Mating pheromone-induced alteration of cell surface proteins in the heterobasidiomycetous yeast Tremella mesenterica.

    PubMed

    Miyakawa, T; Kadota, T; Okubo, Y; Hatano, T; Tsuchiya, E; Fukui, S

    1984-06-01

    Mating pheromone-induced alteration of the cell surface proteins of haploid cells, presumed to play crucial roles in the specific cell-cell interactions during sexual conjugation of Tremella mesenterica , was investigated. Exposed surface proteins were revealed by lactoperoxidase-catalyzed iodination in combination with polyacrylamide gel electrophoresis and autoradiography. From comparison of the molecular species of 125I-labeled surface proteins of the vegetative and the gamete (mating pheromone-treated) cells of the two compatible mating types (ab and AB), it was suggested that a striking change in cell surface structure occurs during the differentiation; although labeled protein species of the vegetative cells of the two mating types were indistinguishable, several new species, both mating type specific and nonspecific, appeared in the gamete cells. Turnover of the labeled proteins of the vegetative cells was negligible, whereas that of the gamete cells was rapid with release of low-molecular-weight labeled proteins in the medium. A role for the labeled surface proteins of the gamete cells in the cell-cell interactions during sexual conjugation was suggested by the following: the surface changes were induced by mating pheromone; the labeled proteins were preferentially localized on the surface of the mating tube; the labeled species appeared sequentially during the differentiation; and mating type-specific species were present in both mating types.

  9. Advances in molecular serotyping and subtyping of Escherichia coli

    DOE PAGES

    Fratamico, Pina M.; DebRoy, Chitrita; Liu, Yanhong; ...

    2016-05-03

    Escherichia coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtypingmore » and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS) of E. coli is replacing established subtyping methods such as pulsedfield gel electrophoresis, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. Furthermore, a variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.« less

  10. Population Snapshot of Streptococcus pneumoniae Serotype 19A Isolates before and after Introduction of Seven-Valent Pneumococcal Vaccination for French Children▿

    PubMed Central

    Mahjoub-Messai, Farah; Doit, Catherine; Koeck, Jean-Louis; Billard, Typhaine; Evrard, Bénédicte; Bidet, Philippe; Hubans, Christine; Raymond, Josette; Levy, Corinne; Cohen, Robert; Bingen, Edouard

    2009-01-01

    Serotype 19A Streptococcus pneumoniae strains are now more frequent in French children than before the introduction of a seven-valent conjugate vaccine (PCV7). By applying multilocus sequence typing to 144 serotype 19A isolates collected before and after beginning PCV7 vaccination, we detected clonal expansion of the preexisting penicillin-intermediate sequence type 276. PMID:19109482

  11. Serotyping of Chlamydia I. Isolates of Ovine Origin

    PubMed Central

    Schachter, Julius; Banks, Joyce; Sugg, Nancy; Sung, Minnie; Storz, J.; Meyer, Karl F.

    1974-01-01

    Eight chlamydial isolates of ovine origin were tested in a plaque reduction system using homologous and heterologous rooster antisera. The eight isolates could be separated into two separate immunotypes. Type 1 included isolates associated with ovine abortion and one agent recovered from the feces of an apparently normal sheep. Type 2 isolates were associated with polyarthritis and conjunctivitis. These two serotypes were not cross-reactive with several chlamydiae of avian origin. Further application of the plaque reduction test may provide a useful means of typing chlamydiae. PMID:4855560

  12. Assortative Mating and Linkage Disequilibrium.

    PubMed

    Hedrick, Philip W

    2017-01-05

    Assortative mating has been suggested to result in an increase in heritability and additive genetic variance through an increase in linkage disequilibrium. The impact of assortative mating on linkage disequilibrium was explicitly examined for the two-locus model of Wright (1921) and two selective assortative mating models. For the Wright (1921) model, when the proportion of assortative mating was high, positive linkage disequilibrium was generated. However, when the proportion of assortative mating was similar to that found in some studies, the amount of linkage disequilibrium was quite low. In addition, the amount of linkage disequilibrium was independent of the level of recombination. For two selective assortative models, the amount of linkage disequilibrium was a function of the amount of recombination. For these models, the linkage disequilibrium generated was negative mainly because repulsion heterozygotes were favored over coupling heterozygotes. From these findings, the impact of assortative mating on linkage disequilibrium, and consequently heritability and additive genetic variance, appears to be small and model-specific.

  13. Assortative Mating and Linkage Disequilibrium

    PubMed Central

    Hedrick, Philip W.

    2016-01-01

    Assortative mating has been suggested to result in an increase in heritability and additive genetic variance through an increase in linkage disequilibrium. The impact of assortative mating on linkage disequilibrium was explicitly examined for the two-locus model of Wright (1921) and two selective assortative mating models. For the Wright (1921) model, when the proportion of assortative mating was high, positive linkage disequilibrium was generated. However, when the proportion of assortative mating was similar to that found in some studies, the amount of linkage disequilibrium was quite low. In addition, the amount of linkage disequilibrium was independent of the level of recombination. For two selective assortative models, the amount of linkage disequilibrium was a function of the amount of recombination. For these models, the linkage disequilibrium generated was negative mainly because repulsion heterozygotes were favored over coupling heterozygotes. From these findings, the impact of assortative mating on linkage disequilibrium, and consequently heritability and additive genetic variance, appears to be small and model-specific. PMID:27784755

  14. Fisetin up-regulates the expression of adiponectin in 3T3-L1 adipocytes via the activation of silent mating type information regulation 2 homologue 1 (SIRT1)-deacetylase and peroxisome proliferator-activated receptors (PPARs).

    PubMed

    Jin, Taewon; Kim, Oh Yoen; Shin, Min-Jeong; Choi, Eun Young; Lee, Sung Sook; Han, Ye Sun; Chung, Ji Hyung

    2014-10-29

    Adiponectin, an adipokine, has been described as showing physiological benefits against obesity-related malfunctions and vascular dysfunction. Several natural compounds that promote the expression and secretion of adipokines in adipocytes could be useful for treating metabolic disorders. This study investigated the effect of fisetin, a dietary flavonoid, on the regulation of adiponectin in adipocytes using 3T3-L1 preadipocytes. The expression and secretion of adiponectin increased in 3T3-L1 cells upon treatment with fisetin in a dose-dependent manner. Fisetin-induced adiponectin secretion was inhibited by peroxisome proliferator-activated receptor (PPAR) antagonists. It was also revealed that fisetin increased the activities of PPARs and silent mating type information regulation 2 homologue 1 (SIRT1) in a dose-dependent manner. Furthermore, the up-regulation of adiponectin and the activation of PPARs induced by fisetin were prevented by a SIRT1 inhibitor. Fisetin also promoted deacetylation of PPAR γ coactivator 1 (PGC-1) and its interaction with PPARs. SIRT knockdown by siRNA significantly decreased both adiponectin production and PPARs-PGC-1 interaction. These results provide evidence that fisetin promotes the gene expression of adiponectin through the activation of SIRT1 and PPARs in adipocytes.

  15. Ondansetron can enhance cisplatin-induced nephrotoxicity via inhibition of multiple toxin and extrusion proteins (MATEs).

    PubMed

    Li, Qing; Guo, Dong; Dong, Zhongqi; Zhang, Wei; Zhang, Lei; Huang, Shiew-Mei; Polli, James E; Shu, Yan

    2013-11-15

    The nephrotoxicity limits the clinical application of cisplatin. Human organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATEs) work in concert in the elimination of cationic drugs such as cisplatin from the kidney. We hypothesized that co-administration of ondansetron would have an effect on cisplatin nephrotoxicity by altering the function of cisplatin transporters. The inhibitory potencies of ondansetron on metformin accumulation mediated by OCT2 and MATEs were determined in the stable HEK-293 cells expressing these transporters. The effects of ondansetron on drug disposition in vivo were examined by conducting the pharmacokinetics of metformin, a classical substrate for OCTs and MATEs, in wild-type and Mate1-/- mice. The nephrotoxicity was assessed in the wild-type and Mate1-/- mice received cisplatin with and without ondansetron. Both MATEs, including human MATE1, human MATE2-K, and mouse Mate1, and OCT2 (human and mouse) were subject to ondansetron inhibition, with much greater potencies by ondansetron on MATEs. Ondansetron significantly increased tissue accumulation and pharmacokinetic exposure of metformin in wild-type but not in Mate1-/- mice. Moreover, ondansetron treatment significantly enhanced renal accumulation of cisplatin and cisplatin-induced nephrotoxicity which were indicated by increased levels of biochemical and molecular biomarkers and more severe pathohistological changes in mice. Similar increases in nephrotoxicity were caused by genetic deficiency of MATE function in mice. Therefore, the potent inhibition of MATEs by ondansetron enhances the nephrotoxicity associated with cisplatin treatment in mice. Potential nephrotoxic effects of combining the chemotherapeutic cisplatin and the antiemetic 5-hydroxytryptamine-3 (5-HT3) receptor antagonists, such as ondansetron, should be investigated in patients.

  16. Characterization of the pathogenome and phylogenomic classification of enteropathogenic Escherichia coli of the O157:non-H7 serotypes

    PubMed Central

    Sanjar, Fatemeh; Rusconi, Brigida; Hazen, Tracy H.; Koenig, Sara S.K.; Mammel, Mark K.; Feng, Peter C.H.; Rasko, David A.; Eppinger, Mark

    2015-01-01

    Escherichia coli of the O157 serogroup are comprised of a diverse collection of more than 100 O157:non-H7 serotypes that are found in the environment, animal reservoir and infected patients and some have been linked to severe outbreaks of human disease. Among these, the enteropathogenic E. coli O157:non-H7 serotypes carry virulence factors that are hallmarks of enterohemorrhagic E. coli, such as causing attaching and effacing lesions during human gastrointestinal tract infections. Given the shared virulence gene pool between O157:H7 and O157:non-H7 serotypes, our objective was to examine the prevalence of virulence traits of O157:non-H7 serotypes within and across their H-serotype and when compared to other E. coli pathovars. We sequenced six O157:non-H7 genomes complemented by four genomes from public repositories in an effort to determine their virulence state and genetic relatedness to the highly pathogenic enterohemorrhagic O157:H7 lineage and its ancestral O55:H7 serotype. Whole-genome-based phylogenomic analysis and molecular typing is indicative of a non-monophyletic origin of the heterogeneous O157:non-H7 serotypes that are only distantly related to the O157:H7 serotype. The availability of multiple genomes enables robust phylogenomic placement of these strains into their evolutionary context, and the assessment of the pathogenic potential of the O157:non-H7 strains in causing human disease. PMID:25962987

  17. Characterization of the pathogenome and phylogenomic classification of enteropathogenic Escherichia coli of the O157:non-H7 serotypes.

    PubMed

    Sanjar, Fatemeh; Rusconi, Brigida; Hazen, Tracy H; Koenig, Sara S K; Mammel, Mark K; Feng, Peter C H; Rasko, David A; Eppinger, Mark

    2015-07-01

    Escherichia coli of the O157 serogroup are comprised of a diverse collection of more than 100 O157:non-H7 serotypes that are found in the environment, animal reservoir and infected patients and some have been linked to severe outbreaks of human disease. Among these, the enteropathogenic E. coli O157:non-H7 serotypes carry virulence factors that are hallmarks of enterohemorrhagic E. coli, such as causing attaching and effacing lesions during human gastrointestinal tract infections. Given the shared virulence gene pool between O157:H7 and O157:non-H7 serotypes, our objective was to examine the prevalence of virulence traits of O157:non-H7 serotypes within and across their H-serotype and when compared to other E. coli pathovars. We sequenced six O157:non-H7 genomes complemented by four genomes from public repositories in an effort to determine their virulence state and genetic relatedness to the highly pathogenic enterohemorrhagic O157:H7 lineage and its ancestral O55:H7 serotype. Whole-genome-based phylogenomic analysis and molecular typing is indicative of a non-monophyletic origin of the heterogeneous O157:non-H7 serotypes that are only distantly related to the O157:H7 serotype. The availability of multiple genomes enables robust phylogenomic placement of these strains into their evolutionary context, and the assessment of the pathogenic potential of the O157:non-H7 strains in causing human disease.

  18. Hemagglutinin gene shuffling among Clostridium botulinum serotypes C and D yields distinct sugar recognition of the botulinum toxin complex.

    PubMed

    Miyata, Keita; Suzuki, Tomonori; Hayashi, Shintaro; Miyashita, Shin-Ichiro; Ohyama, Tohru; Niwa, Koichi; Watanabe, Toshihiro; Sagane, Yoshimasa

    2015-10-01

    Clostridium botulinum strains produce a large-sized toxin complex (TC) that is composed of botulinum neurotoxin (BoNT), non-toxic non-hemagglutinin and three different hemagglutinins (HA-70, HA-33 and HA-17). HA components enhance toxin delivery across the intestinal cell wall in a sugar chain-dependent manner. Here we characterized the sugar recognition of serotype D strain 1873 (D-1873) botulinum L-TC. Most L-TCs produced by serotype C and D strains bind to cells via interactions between HA-33 and cell surface sialo-oligosaccharides. However, like the previously reported L-TC produced by serotype C strain Yoichi (C-Yoichi), D-1873 L-TC binds only to cells that have been treated with neuraminidase, indicating that they recognize asialo-oligosaccharides. The D-1873 HA-33 amino acid sequence is similar to that of C-Yoichi, but had lower similarity to the majority of serotype C and D HA-33s. A comparison of TC component primary structures for 12 serotype C and D strains suggested that at least three types of HA-33 genes exist, and these are shuffled among the serotype C and D strains independently of BoNT serotype. This shuffling produces the distinct sugar recognition of serotype C and D botulinum TCs.

  19. Social discrimination of cage-mates and non-cage-mates by rats.

    PubMed

    Jones, Samantha; Burman, Oliver; Mendl, Michael

    2014-07-01

    The ability to discriminate between group-mates and non-group-mates likely underpins the occurrence of affiliative and aggressive behaviour towards 'in-group' and 'out-group' individuals. Here we present two experiments aimed at testing the ability of rats (Rattus norvegicus) to discriminate between cage-mate (CM: animals residing in the subject's home cage) and non-cage-mate (NCM) conspecifics. In experiment 1, rats were trained to discriminate between different exemplars of CM and NCM using a lever pressing task employing symmetrical reinforcement. Subjects did not reach performance criterion, but they did show some evidence of discrimination between the two types of stimuli. In experiment 2, we employed a digging task to determine if rats can discriminate between odour cues from CM and NCM presented simultaneously on two sand-filled bowls. Subjects reached performance criterion on the first pair of odours, and on three more different pairs of CM and NCM odours. The results of a reversal task, using a fifth pair of odours, indicate that the rats were using a common factor to discriminate between social cues from CM and NCM conspecifics, rather than learning each pair independently. Possible candidates include a group-specific odour cue, or the development of a CM/NCM category concept.

  20. Assortative mating and differential male mating success in an ash hybrid zone population

    PubMed Central

    Gérard, Pierre R; Klein, Etienne K; Austerlitz, Frédéric; Fernández-Manjarrés, Juan F; Frascaria-Lacoste, Nathalie

    2006-01-01

    Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash) and F. angustifolia Vahl (narrow-leaved ash), which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears to maintain this hybrid

  1. Brassica oleracea MATE encodes a citrate transporter and enhances aluminum tolerance in Arabidopsis thaliana.

    PubMed

    Wu, Xinxin; Li, Ren; Shi, Jin; Wang, Jinfang; Sun, Qianqian; Zhang, Haijun; Xing, Yanxia; Qi, Yan; Zhang, Na; Guo, Yang-Dong

    2014-08-01

    The secretion of organic acid anions from roots is an important mechanism for plant aluminum (Al) tolerance. Here we report cloning and characterizing BoMATE (KF031944), a multidrug and toxic compound extrusion (MATE) family gene from cabbage (Brassica oleracea). The expression of BoMATE was more abundant in roots than in shoots, and it was highly induced by Al treatment. The (14)C-citrate efflux experiments in oocytes demonstrated that BoMATE is a citrate transporter. Electrophysiological analysis and SIET analysis of Xenopus oocytes expressing BoMATE indicated BoMATE is activated by Al. Transient expression of BoMATE in onion epidermal cells demonstrated that it localized to the plasma membrane. Compared with the wild-type Arabidopsis, the transgenic lines constitutively overexpressing BoMATE enhanced Al tolerance and increased citrate secretion. In addition, Arabidopsis transgenic lines had a lower K(+) efflux and higher H(+) efflux, in the presence of Al, than control wild type in the distal elongation zone (DEZ). This is the first direct evidence that MATE protein is involved in the K(+) and H(+) flux in response to Al treatment. Taken together, our results show that BoMATE is an Al-induced citrate transporter and enhances aluminum tolerance in Arabidopsis thaliana.

  2. Aggressive assembly of pyrosequencing reads with mates

    PubMed Central

    Miller, Jason R.; Delcher, Arthur L.; Koren, Sergey; Venter, Eli; Walenz, Brian P.; Brownley, Anushka; Johnson, Justin; Li, Kelvin; Mobarry, Clark; Sutton, Granger

    2008-01-01

    Motivation: DNA sequence reads from Sanger and pyrosequencing platforms differ in cost, accuracy, typical coverage, average read length and the variety of available paired-end protocols. Both read types can complement one another in a ‘hybrid’ approach to whole-genome shotgun sequencing projects, but assembly software must be modified to accommodate their different characteristics. This is true even of pyrosequencing mated and unmated read combinations. Without special modifications, assemblers tuned for homogeneous sequence data may perform poorly on hybrid data. Results: Celera Assembler was modified for combinations of ABI 3730 and 454 FLX reads. The revised pipeline called CABOG (Celera Assembler with the Best Overlap Graph) is robust to homopolymer run length uncertainty, high read coverage and heterogeneous read lengths. In tests on four genomes, it generated the longest contigs among all assemblers tested. It exploited the mate constraints provided by paired-end reads from either platform to build larger contigs and scaffolds, which were validated by comparison to a finished reference sequence. A low rate of contig mis-assembly was detected in some CABOG assemblies, but this was reduced in the presence of sufficient mate pair data. Availability: The software is freely available as open-source from http://wgs-assembler.sf.net under the GNU Public License. Contact: jmiller@jcvi.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:18952627

  3. Deletion of a Yci1 Domain Protein of Candida albicans Allows Homothallic Mating in MTL Heterozygous Cells

    PubMed Central

    Sun, Yuan; Gadoury, Christine; Hirakawa, Matthew P.; Bennett, Richard J.; Harcus, Doreen; Marcil, Anne

    2016-01-01

    ABSTRACT It has been proposed that the ancestral fungus was mating competent and homothallic. However, many mating-competent fungi were initially classified as asexual because their mating capacity was hidden behind layers of regulation. For efficient in vitro mating, the essentially obligate diploid ascomycete pathogen Candida albicans has to change its mating type locus from heterozygous MTLa/α to homozygous MTLa/a or MTLα/α and then undergo an environmentally controlled epigenetic switch to the mating-competent opaque form. These requirements greatly reduce the potential for C. albicans mating. Deletion of the Yci1 domain gene OFR1 bypasses the need for C. albicans cells to change the mating type locus from heterozygous to homozygous prior to switching to the opaque form and mating and allows homothallic mating of MTL heterozygous strains. This bypass is carbon source dependent and does not occur when cells are grown on glucose. Transcriptional profiling of ofr1 mutant cells shows that in addition to regulating cell type and mating circuitry, Ofr1 is needed for proper regulation of histone and chitin biosynthesis gene expression. It appears that OFR1 is a key regulator in C. albicans and functions in part to maintain the cryptic mating phenotype of the pathogen. PMID:27118591

  4. Estrogens Can Disrupt Amphibian Mating Behavior

    PubMed Central

    Hoffmann, Frauke; Kloas, Werner

    2012-01-01

    The main component of classical contraceptives, 17α-ethinylestradiol (EE2), has high estrogenic activity even at environmentally relevant concentrations. Although estrogenic endocrine disrupting compounds are assumed to contribute to the worldwide decline of amphibian populations by adverse effects on sexual differentiation, evidence for EE2 affecting amphibian mating behaviour is lacking. In this study, we demonstrate that EE2 exposure at five different concentrations (0.296 ng/L, 2.96 ng/L, 29.64 ng/L, 2.96 µg/L and 296.4 µg/L) can disrupt the mating behavior of adult male Xenopus laevis. EE2 exposure at all concentrations lowered male sexual arousal, indicated by decreased proportions of advertisement calls and increased proportions of the call type rasping, which characterizes a sexually unaroused state of a male. Additionally, EE2 at all tested concentrations affected temporal and spectral parameters of the advertisement calls, respectively. The classical and highly sensitive biomarker vitellogenin, on the other hand, was only induced at concentrations equal or higher than 2.96 µg/L. If kept under control conditions after a 96 h EE2 exposure (2.96 µg/L), alterations of male advertisement calls vanish gradually within 6 weeks and result in a lower sexual attractiveness of EE2 exposed males toward females as demonstrated by female choice experiments. These findings indicate that exposure to environmentally relevant EE2 concentrations can directly disrupt male mate calling behavior of X. laevis and can indirectly affect the mating behavior of females. The results suggest the possibility that EE2 exposure could reduce the reproductive success of EE2 exposed animals and these effects might contribute to the global problem of amphibian decline. PMID:22355410

  5. Diversity of group B streptococcus serotypes causing urinary tract infection in adults.

    PubMed

    Ulett, Kimberly B; Benjamin, William H; Zhuo, Fenglin; Xiao, Meng; Kong, Fanrong; Gilbert, Gwendolyn L; Schembri, Mark A; Ulett, Glen C

    2009-07-01

    Serotypes of group B streptococcus (GBS) that cause urinary tract infection (UTI) are poorly characterized. We conducted a prospective study of GBS UTI in adults to define the clinical and microbiological characteristics of these infections, including which serotypes cause disease. Patients who had GBS cultured from urine over a 1-year period were grouped according to symptoms, bacteriuria, and urinalysis. Demographic data were obtained by reviewing medical records. Isolates were serotyped by latex agglutination and multiplex PCR-reverse line blotting (mPCR/RLB). Antibiotic susceptibilities were determined by disc diffusion. GBS was cultured from 387/34,367 consecutive urine samples (1.1%): 62 patients had bacteriuria of >10(7) CFU/liter and at least one UTI symptom; of these patients, 31 had urinary leukocyte esterase and pyuria (others not tested), 50 (81%) had symptoms consistent with cystitis, and 12 (19%) had symptoms of pyelonephritis. Compared with controls (who had GBS isolated without symptoms), a prior history of UTI was an independent risk factor for disease. Increased age was also significantly associated with acute infection. Serotyping results were consistent between latex agglutination and mPCR/RLB for 331/387 (85.5%) isolates; 22 (5.7%) and 7 (1.8%) isolates were nontypeable with antisera and by mPCR/RLB, respectively; and 45/56 (80.4%) isolates with discrepant results were typed by mPCR/RLB as belonging to serotype V. Serotypes V, Ia, and III caused the most UTIs; serotypes II, Ib, and IV were less common. Nontypeable GBS was not associated with UTI. Erythromycin (39.5%) and clindamycin (26.4%) resistance was common. We conclude that a more diverse spectrum of GBS serotypes causes UTI than previously recognized, with the exception of nontypeable GBS.

  6. Determination of bovine rotavirus G and P serotypes in italy by PCR.

    PubMed

    Falcone, E; Tarantino, M; Di Trani, L; Cordioli, P; Lavazza, A; Tollis, M

    1999-12-01

    Determination of the G and P serotypes of group A bovine rotaviruses from 149 samples of feces or intestinal contents collected from calves showing clinical signs of neonatal diarrhea was performed by a nested reverse transcription-PCR typing assay. The G6 serotype was the most prevalent, accounting for viruses in 55.7% of the samples; viruses of the G10 and G8 serotypes were found in 34.9 and 4.7% of the samples, respectively. The virus in one sample (0.7%) was not classified due to concomitant infection with G6 and G8 strains, whereas viruses in six samples (4.0%) could not be characterized with any of the three G serotype-specific primers selected for the present study. When examined for their P-serotype specificities, viruses in 55 and 42.3% of the samples were characterized as P[11] and P[5], respectively, no P[1] serotype was identified, and viruses in 2.7% of the samples could not be classified due to multiple reactivity with both P[5]- and P[11]-specific primers. Various combinations of G and P serotypes were observed, the most frequent being G6,P[5] (38.3%), G10,P[11] (31.5%), and G6,P[11] (15.4%). The results of the present study, while contributing to a better understanding of the epidemiology of bovine rotaviruses in Italy, address the relevance of serotype specificity with regard to the constancy of the quality of bovine rotavirus vaccines under different field conditions.

  7. Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in southern Brazil

    PubMed Central

    Pulido-Landínez, M; Sánchez-Ingunza, R; Guard, J; do Nascimento, V Pinheiro

    2013-01-01

    To assess diversity of Salmonella enterica serotypes present in poultry and their environment from southern Brazil, the Kauffmann–White–Le Minor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked intergenic sequence ribotyping (ISR) region that assesses single nucleotide polymorphisms occurring around a 5S ribosomal gene. Serotypes identified were Heidelberg (40·6%), Enteritidis (34·2%), Hadar (8·4%), Typhimurium (3·9%), Gallinarum (3·2%), Agona (1·3%), Cerro (1·3%), Livingstone (1·3%), Infantis (0·6%), Isangi (0·6%), Mbandaka (0·6%), Montevideo (0·6%) and Senftenberg (0·6%). Three unique ISRs were detected from four strains. Day old chicks yielded only S. Enteritidis, whereas S. Heidelberg was most often associated with poultry carcasses. Overall agreement between KWL and ISR was 85·2%, with disagreement possibly due to the ability of ISR to detect mixtures of serotypes in culture. Overall, ISR provided more information than did KWL about the ecology of Salm. enterica on-farm. The O-antigen group D Salm. enterica serovars such as Pullorum, Gallinarum and Enteritidis appear susceptible to overgrowth by other serotypes. Significance and Impact of the Study Single nucleotide polymorphisms found in a group of poultry-associated Salmonella isolates from southern Brazil provided evidence of mixtures of serovar group D serotypes on-farm and in single samples from birds. This finding suggests that co-infection and interserotype competition of Salmonella enterica in poultry could impact the incidence of disease in animals or humans. In addition, unique serotypes were identified on-farm that escaped characterization by antibody typing. Application of cost-efficient and highly discriminatory genomic methods for assigning serotype may alter concepts about the epidemiology of Salm. enterica on-farm and in foods. PMID:23734786

  8. Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes

    PubMed Central

    Martínez-Robles, Ángel Manuel; Loyola-Rodríguez, Juan Pablo; Zavala-Alonso, Norma Verónica; Martinez-Martinez, Rita Elizabeth; Ruiz, Facundo; Lara-Castro, René Homero; Donohué-Cornejo, Alejandro; Reyes-López, Simón Yobanny; Espinosa-Cristóbal, León Francisco

    2016-01-01

    (1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria. PMID:28335264

  9. Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes.

    PubMed

    Martínez-Robles, Ángel Manuel; Loyola-Rodríguez, Juan Pablo; Zavala-Alonso, Norma Verónica; Martinez-Martinez, Rita Elizabeth; Ruiz, Facundo; Lara-Castro, René Homero; Donohué-Cornejo, Alejandro; Reyes-López, Simón Yobanny; Espinosa-Cristóbal, León Francisco

    2016-07-22

    (1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria.

  10. A double role of sperm in scorpions: the mating plug of Euscorpius italicus (Scorpiones: Euscorpiidae) consists of sperm.

    PubMed

    Althaus, Sarah; Jacob, Alain; Graber, Werner; Hofer, Deborah; Nentwig, Wolfgang; Kropf, Christian

    2010-04-01

    Mating plugs occluding the female gonopore after mating are a widespread phenomenon. In scorpions, two main types of mating plugs are found: sclerotized mating plugs being parts of the spermatophore that break off during mating, and gel-like mating plugs being gelatinous fluids that harden in the female genital tract. In this study, the gel-like mating plug of Euscorpius italicus was investigated with respect to its composition, fine structure, and changes over time. Sperm forms the major component of the mating plug, a phenomenon previously unknown in arachnids. Three parts of the mating plug can be distinguished. The part facing the outside of the female (outer part) contains sperm packages containing inactive spermatozoa. In this state, sperm is transferred. In the median part, the sperm packages get uncoiled to single spermatozoa. In the inner part, free sperm is embedded in a large amount of secretions. Fresh mating plugs are soft gelatinous, later they harden from outside toward inside. This process is completed after 3-5 days. Sperm from artificially triggered spermatophores could be activated by immersion in insect Ringer's solution indicating that the fluid condition in the females' genital tract or females' secretions causes sperm activation. Because of the male origin of the mating plug, it has likely evolved under sperm competition or sexual conflict. As females refused to remate irrespective of the presence or absence of a mating plug, females may have changed their mating behavior in the course of evolution from polyandry to monandry.

  11. Both Geography and Ecology Contribute to Mating Isolation in Guppies

    PubMed Central

    Schwartz, Amy K.; Weese, Dylan J.; Bentzen, Paul; Kinnison, Michael T.; Hendry, Andrew P.

    2010-01-01

    Local adaptation to different environments can promote mating isolation – either as an incidental by-product of trait divergence, or as a result of selection to avoid maladaptive mating. Numerous recent empirical examples point to the common influence of divergent natural selection on speciation based largely on evidence of strong pre-mating isolation between populations from different habitat types. Accumulating evidence for natural selection's influence on speciation is therefore no longer a challenge. The difficulty, rather, is in determining the mechanisms involved in the progress of adaptive divergence to speciation once barriers to gene flow are already present. Here, we present results of both laboratory and field experiments with Trinidadian guppies (Poecilia reticulata) from different environments, who do not show complete reproductive isolation despite adaptive divergence. We investigate patterns of mating isolation between populations that do and do not exchange migrants and show evidence for both by-product and reinforcement mechanisms depending on female ecology. Specifically, low-predation females discriminate against all high-predation males thus implying a by-product mechanism, whereas high-predation females only discriminate against low-predation males from further upstream in the same river, implying selection to avoid maladaptive mating. Our study thus confirms that mechanisms of adaptive speciation are not necessarily mutually exclusive and uncovers the complex ecology-geography interactions that underlie the evolution of mating isolation in nature. PMID:21179541

  12. Subtyping of Salmonella Food Isolates Suggests the Geographic Clustering of Serotype Telaviv.

    PubMed

    Durul, Bora; Acar, Sinem; Bulut, Ece; Kyere, Emmanuel O; Soyer, Yeşim

    2015-12-01

    Salmonella is commonly found in a variety of food products and is a major cause of bacterial foodborne illness throughout the world. In this study, we investigated the prevalence and diversity of Salmonella in eight different food types: sheep ground meat, cow ground meat, chicken meat, cow offal, traditional Sanliurfa cheese, unripened feta cheese, pistachios, and isot (a spice blend of dried red peppers specific to Sanliurfa), traditionally and commonly consumed in Turkey. Among 192 food samples, Salmonella was detected in 59 samples, with the highest prevalence in raw poultry parts (58%) and offal (58%) samples, while Salmonella was not detected in pistachios and dried red pepper. Resultant Salmonella isolates were characterized by serotyping, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Ten different serotypes represented 10 MLST sequence types (STs) with 1 novel ST and 17 PFGE types. Antimicrobial resistance profiling revealed that 30.5% of the isolates were resistant to two or more antimicrobials. Salmonella enterica subsp. enterica serotype Telaviv, which is rare throughout the world, was the second most common serotype isolated from food samples in this study, suggesting that this serotype might be one of the subtypes that is endemic to Turkey.

  13. [A possible fifth dengue virus serotype].

    PubMed

    da Silva Voorham, Júlia M

    2014-01-01

    Sylvatic dengue viruses are both evolutionarily and ecologically distinguishable from the human dengue virus (DENV). Sporadic episodes of sylvatic human infections in West Africa and Southeast Asia suggest that sylvatic DENV regularly come into contact with human beings. Following a study on the sylvatic transmission cycle in Malaysia in 2007, researchers announced that a new DENV serotype, DENV-5, had been discovered. Scientists are still sceptical about these new findings, and indicate that more data is necessary to determine whether this 'new' virus really is a different serotype or whether it is a variant of one of the four DENV serotypes already known. The good news is that this new variant has not yet established itself in the human transmission cycle. However, if it really is a new serotype this will have implications for the long-term control of dengue using vaccines currently under development.

  14. Classification of Proteus penneri lipopolysaccharides into core region serotypes.

    PubMed

    Palusiak, Agata

    2016-12-01

    The frequency of P. penneri isolation from hospital patients, mostly from urine and wounds, keeps on growing, and numerous isolates are multi-drug resistant. P. penneri rods produce lipopolysaccharide (LPS), which may lead to the septic shock. Until now, O-specific polysaccharide has been the best structurally and serologically characterized region of P. penneri LPS. It is worth having an insight into the serological specificity of both poly- and oligosaccharide parts of P. penneri LPS. The P. penneri core region is less structurally diverse than OPS, but still, among other enterobacterial LPS core regions, it is characterized by structural variability. In the present study, the serological reactivity of 25 P. penneri LPS core regions was analyzed by ELISA, passive immunohemolysis and Western blot technique using five polyclonal P. penneri antisera after or without their adsorption with the respective LPSs. The results allowed the assignment of the tested strains to five new core serotypes, which together with published serological studies led to the creation of the first serotyping scheme based on LPS core reactivities of 35 P. penneri and three P. mirabilis strains. Together with the O types scheme, it will facilitate assigning Proteus LPSs of clinical isolates into appropriate O and R serotypes.

  15. The evolution of mate choice and mating biases.

    PubMed Central

    Kokko, Hanna; Brooks, Robert; Jennions, Michael D; Morley, Josephine

    2003-01-01

    We review the current status of three well-established models (direct benefits, indirect benefits and sensory drive) and one newcomer (antagonistic chase-away) of the evolution of mate choice and the biases that are expressed during choice. We highlight the differences and commonalities in the underlying genetics and evolutionary dynamics of these models. We then argue that progress in understanding the evolution of mate choice is currently hampered by spurious distinctions among models and a misguided tendency to test the processes underlying each model as mutually exclusive alternatives. Finally, we suggest potentially fruitful directions for future theoretical and empirical research. PMID:12769467

  16. The evolution of mate choice and mating biases.

    PubMed

    Kokko, Hanna; Brooks, Robert; Jennions, Michael D; Morley, Josephine

    2003-03-22

    We review the current status of three well-established models (direct benefits, indirect benefits and sensory drive) and one newcomer (antagonistic chase-away) of the evolution of mate choice and the biases that are expressed during choice. We highlight the differences and commonalities in the underlying genetics and evolutionary dynamics of these models. We then argue that progress in understanding the evolution of mate choice is currently hampered by spurious distinctions among models and a misguided tendency to test the processes underlying each model as mutually exclusive alternatives. Finally, we suggest potentially fruitful directions for future theoretical and empirical research.

  17. Serotype- and virulence-associated gene profile of Streptococcus suis isolates from pig carcasses in Chiang Mai Province, Northern Thailand

    PubMed Central

    WONGSAWAN, Kanruethai; GOTTSCHALK, Marcelo; THARAVICHITKUL, Prasit

    2014-01-01

    In this present study, the serotype of 40 Streptococcus suis isolates from submaxillary glands of pig carcasses sold in wet markets in Chiang Mai Province, northern Thailand, was investigated. Eleven serotypes, including types 2, 3, 4, 5, 7, 8, 9, 17, 21, 22 and 31, were found in the isolates by a Multiplex PCR combined with serum agglutination. Of the eleven serotypes present, type 3 was the most prevalent, while types 2, 4, 5 and 21 were of primary interest due to their human isolate serotype. The mrp+/epf − /sly − genotype was found to be the most prevalent genotype. This study indicates the importance of effective control of human S. suis infection due to raw pork or pig carcass handling in northern Thailand. PMID:25367105

  18. Females tend to prefer genetically similar mates in an island population of house sparrows

    PubMed Central

    2014-01-01

    Background It is often proposed that females should select genetically dissimilar mates to maximize offspring genetic diversity and avoid inbreeding. Several recent studies have provided mixed evidence, however, and in some instances females seem to prefer genetically similar males. A preference for genetically similar mates can be adaptive if outbreeding depression is more harmful than inbreeding depression or if females gain inclusive fitness benefits by mating with close kin. Here, we investigated genetic compatibility and mating patterns in an insular population of house sparrow (Passer domesticus), over a three-year period, using 12 microsatellite markers and one major histocompability complex (MHC) class I gene. Given the small population size and the distance from the mainland, we expected a reduced gene flow in this insular population and we predicted that females would show mating preferences for genetically dissimilar mates. Results Contrary to our expectation, we found that offspring were less genetically diverse (multi-locus heterozygosity) than expected under a random mating, suggesting that females tended to mate with genetically similar males. We found high levels of extra-pair paternity, and offspring sired by extra-pair males had a better fledging success than those sired by the social male. Again, unexpectedly, females tended to be more closely related to extra-pair mates than to their social mates. Our results did not depend on the type of genetic marker used, since microsatellites and MHC genes provided similar results, and we found only little evidence for MHC-dependent mating patterns. Conclusions These results are in agreement with the idea that mating with genetically similar mates can either avoid the disruption of co-adapted genes or confer a benefit in terms of kin selection. PMID:24621140

  19. The RAD7 and RAD16 genes, which are essential for pyrimidine dimer removal from the silent mating type loci, are also required for repair of the nontranscribed strand of an active gene in Saccharomyces cerevisiae.

    PubMed Central

    Verhage, R; Zeeman, A M; de Groot, N; Gleig, F; Bang, D D; van de Putte, P; Brouwer, J

    1994-01-01

    The rad16 mutant of Saccharomyces cerevisiae was previously shown to be impaired in removal of UV-induced pyrimidine dimers from the silent mating-type loci (D. D. Bang, R. A. Verhage, N. Goosen, J. Brouwer, and P. van de Putte, Nucleic Acids Res. 20:3925-3931, 1992). Here we show that rad7 as well as rad7 rad16 double mutants have the same repair phenotype, indicating that the RAD7 and RAD16 gene products might operate in the same nucleotide excision repair subpathway. Dimer removal from the genome overall is essentially incomplete in these mutants, leaving about 20 to 30% of the DNA unrepaired. Repair analysis of the transcribed RPB2 gene shows that the nontranscribed strand is not repaired at all in rad7 and rad16 mutants, whereas the transcribed strand is repaired in these mutants at a fast rate similar to that in RAD+ cells. When the results obtained with the RPB2 gene can be generalized, the RAD7 and RAD16 proteins not only are essential for repair of silenced regions but also function in repair of nontranscribed strands of active genes in S. cerevisiae. The phenotype of rad7 and rad16 mutants closely resembles that of human xeroderma pigmentosum complementation group C (XP-C) cells, suggesting that RAD7 and RAD16 in S. cerevisiae function in the same pathway as the XPC gene in human cells. RAD4, which on the basis of sequence homology has been proposed to be the yeast XPC counterpart, seems to be involved in repair of both inactive and active yeast DNA, challenging the hypothesis that RAD4 and XPC are functional homologs. Images PMID:8065346

  20. Dominance of Serotype Ia among Group B Streptococci Causing Invasive Infections in Nonpregnant Adults in Portugal

    PubMed Central

    Martins, E. R.; Melo-Cristino, J.

    2012-01-01

    The population of group B streptococci (GBS) associated with invasive infections in nonpregnant adults from 2001 to 2008 was analyzed in isolates submitted from 24 hospital laboratories in Portugal (n = 225). The isolates were characterized by antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and surface protein gene profiling. GBS invasive cases were found more frequently among men in all age groups. In addition, serotype Ia was the most frequent in our collection, whereas serotype V is dominant elsewhere. Serotype Ia was represented mainly by a single PFGE cluster defined by sequence type 23 (ST23) and surface protein gene eps and by ST24 and bca, similarly to neonatal invasive infections in Portugal, indicating that the same genetic lineages can be responsible for both vaginal colonization and invasive disease in all age groups. In contrast, the hypervirulent serotype III/ST17 neonatal lineage was responsible for a minority of infections. Serotype V isolates were distributed into two genetic lineages, one defined by ST1 and surface protein gene alp3 and macrolide resistant, and another presenting with ST2 and eps and fully susceptible to all antimicrobials tested. The erm(TR) gene was the most frequently found among erythromycin-resistant isolates, while the bovine-associated tet(O) gene was found in a minority of tetracycline-resistant isolates. Our data emphasize the importance of local identification of the genetic lineages responsible for GBS invasive infections in nonpregnant adults. The dominance of serotype Ia in invasive disease in Portugal highlights the importance of this serotype in GBS pathogenesis. PMID:22219307

  1. Dominance of serotype Ia among group B Streptococci causing invasive infections in nonpregnant adults in Portugal.

    PubMed

    Martins, E R; Melo-Cristino, J; Ramirez, M

    2012-04-01

    The population of group B streptococci (GBS) associated with invasive infections in nonpregnant adults from 2001 to 2008 was analyzed in isolates submitted from 24 hospital laboratories in Portugal (n = 225). The isolates were characterized by antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and surface protein gene profiling. GBS invasive cases were found more frequently among men in all age groups. In addition, serotype Ia was the most frequent in our collection, whereas serotype V is dominant elsewhere. Serotype Ia was represented mainly by a single PFGE cluster defined by sequence type 23 (ST23) and surface protein gene eps and by ST24 and bca, similarly to neonatal invasive infections in Portugal, indicating that the same genetic lineages can be responsible for both vaginal colonization and invasive disease in all age groups. In contrast, the hypervirulent serotype III/ST17 neonatal lineage was responsible for a minority of infections. Serotype V isolates were distributed into two genetic lineages, one defined by ST1 and surface protein gene alp3 and macrolide resistant, and another presenting with ST2 and eps and fully susceptible to all antimicrobials tested. The erm(TR) gene was the most frequently found among erythromycin-resistant isolates, while the bovine-associated tet(O) gene was found in a minority of tetracycline-resistant isolates. Our data emphasize the importance of local identification of the genetic lineages responsible for GBS invasive infections in nonpregnant adults. The dominance of serotype Ia in invasive disease in Portugal highlights the importance of this serotype in GBS pathogenesis.

  2. Development of a peptide based latex agglutination assay for serotype identification of foot and mouth disease virus.

    PubMed

    Kaur, Dilpreet; Kaur, Gurpreet; Chandra, Mudit; Saxena, Hari M; Dwivedi, Padam N

    2013-02-01

    Out of 200 serum samples collected from cattle (142) and buffaloes (58) of various ages and sexand subjected to latex agglutination test (LAT) using serotype specific peptides (O, A, Asia 1) and also with peptide for non-structural protein 2B (NSP-2B), 114 (70%) samples were positive against FMDV type 'O', 102 (51%) against serotype 'A' and 104 (52%) against serotype 'Asia 1'. With NSP-2B peptide a total of 71 (35.5%) samples were positive. The results suggest that LAT could be used for the diagnosis of foot and mouth disease virus as it is easy, cheap and effective test.

  3. Restricted association between biotypes and serotypes within group A streptococci.

    PubMed

    Bouvet, A; Geslin, P; Kriz-Kuzemenska, P; Blanc, V; Devine, C; Grimont, F

    1994-05-01

    Investigating individual variations between different isolates of group A streptococci, we observed a close correlation between biotypes and serotypes in 46 strains from pharyngitis patients. Biotyping, carried out with a commercially available rapid identification gallery, delineated 10 different associations of characteristics, designated biotypes 1 to 10, observed both in the manufacturer's (127 strains) and our personal (98 strains) collections of group A strains. Only the most frequent biotypes (biotypes 1 to 6) were observed in the pharyngitis cohort, but the overall frequencies of the biotypes did not display striking differences compared with the control collections. Serotyping of the pharyngitis strains showed that each M type was restricted to a sole biotype. For example, M types 1, 4, and 28 were found only in biotype 1 and M type 6 was found only in biotype 6 strains. This association was not due to an epidemiologic bias, since it was also observed in a control series consisting of reference strains and isolates from distant countries (the United States and Czech Republic versus France). An exception was for M type 78, which exhibited biotype 3 or biotype 4. Investigation of the heterogeneity of the strains at the DNA level showed no significant variations of the ribotype patterns between strains of different biotypes, confirming that group A streptococci belong to a unique and homogeneous species. This previously undescribed association between serotypes and biotypes is of interest for a rapid and preliminary characterization of strains isolated in individual patients or during an outbreak. A possible pathogenic association of some biotypic characteristics with specific M proteins is envisaged.

  4. How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples

    PubMed Central

    Conroy-Beam, Daniel; Buss, David M.

    2016-01-01

    Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294) we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection. PMID:27276030

  5. Antibiotic Susceptibility of Streptococcus mutans: Comparison of Serotype Profiles

    PubMed Central

    Little, Wayne A.; Thomson, Lynn A.; Bowen, William H.

    1979-01-01

    A total of 82 strains of Streptococcus mutans representing serotypes a through g were tested for susceptibility to erythromycin, penicillin, methicillin, lincomycin, tetracycline, vancomycin, gentamicin, streptomycin, neomycin, kanamycin, bacitracin, and polymyxin B. Strains included stock cultures and isolates from human and animal dental plaque. Minimal inhibitory concentrations were determined by a broth-microdilution procedure. The major differences in antibiotic susceptibility observed among the serotypes resulted with antibiotics which act on the cell surface. Bacitracin was most active against serotype a strains and polymyxin B against serotype b strains. Serotypes a, d, and g were less susceptible than the other serotypes to methicillin. PMID:464571

  6. Serotypes in Saccharomyces telluris: Their relation to source of isolation

    USGS Publications Warehouse

    Hasenclever, H.F.; Kocan, R.M.

    1973-01-01

    Three serotypes have been characterized with three reference strains of Saccharomyces telluris and designated as A, B, and C. One reference strain of Torpulopsis bovina, the imperfect form of S. telluris, belonged to serotype B. Strains of S. telluris isolated from four columbid species were serotyped. All 98 strains of this yeast isolated from Columba livia belonged to serotype B. Three other columbid species, C. leucocephala, C. fasciata, and Zenaidura macroura harbored strains of serotype C only. Serotype A was not isolated from any of the avian species.

  7. Interim results of an ecological experiment — Conjugate vaccination against the pneumococcus and serotype replacement

    PubMed Central

    Hausdorff, William P; Hanage, William P

    2016-01-01

    Streptococcus pneumoniae has more than 95 serotypes, each of which presumably can cause sepsis, meningitis, pneumonia, and acute otitis media. Pneumococcal conjugate vaccines (PCV) targeted against a limited number of serotypes have nonetheless revealed an impressive impact on each manifestation of pneumococcal disease. At the same time, growing evidence of significant non-vaccine type (NVT) replacement disease following implementation of infant PCV programs has raised questions about the long-term viability of PCV immunization strategies and how to optimize PCV formulations. We discuss here theoretical and practical considerations regarding serotype replacement, and provide a snapshot of the most important NVT types seen to date after implementation of the 2 higher-valent PCVs. PMID:26905681

  8. Weather Specialist/Aerographer's Mate.

    ERIC Educational Resources Information Center

    Chanute AFB Technical Training Center, IL.

    This course trains Air Force personnel to perform duties prescribed for weather specialists and aerographer's mates. Training includes meteorology, surface and ship observation, weather radar, operation of standard weather instruments and communications equipment, and decoding and plotting of surface and upper air codes upon standard maps and…

  9. Neural Circuits: Male Mating Motifs.

    PubMed

    Benton, Richard

    2015-09-02

    Characterizing microcircuit motifs in intact nervous systems is essential to relate neural computations to behavior. In this issue of Neuron, Clowney et al. (2015) identify recurring, parallel feedforward excitatory and inhibitory pathways in male Drosophila's courtship circuitry, which might explain decisive mate choice.

  10. Rise of multidrug-resistant non-vaccine serotype 15A Streptococcus pneumoniae in the United Kingdom, 2001 to 2014

    PubMed Central

    Sheppard, Carmen; Fry, Norman K.; Mushtaq, Shazad; Woodford, Neil; Reynolds, Rosy; Janes, Regina; Pike, Rachel; Hill, Robert; Kimuli, Maimuna; Staves, Peter; Doumith, Michel; Harrison, Timothy; Livermore, David M

    2016-01-01

    Conjugate vaccines have reduced pneumococcal disease in vaccinated children and unvaccinated adults, but non-vaccine serotypes are of concern, particularly if antibiotic resistant. We reviewed Streptococcus pneumoniae collected via: (i) the British Society for Antimicrobial Chemotherapy (BSAC) surveillances from 2001–2014; (ii) Public Health England’s (PHE) invasive isolate surveillance from 2005–2014 and (iii) referral to PHE for resistance investigation from 2005–2014. Serotype 15A increased in all series, with many representatives showing triple resistance to macrolides, tetracyclines and penicillin. 15A was consistently among the 10 most prevalent serotypes from 2011 in PHE and BSAC invasive isolate/bacteraemia surveillance but never previously; 26–33% of these invasive 15A isolates had triple resistance. BSAC respiratory isolates were only serotyped in 2013/14 and 2014/15 (October to September); 15A was most prevalent serotype in both periods, comprising 9–11% of isolates, 38–48% of them with triple resistance. Serotype 15A represented 0–4% of S. pneumoniae referred to PHE for reference investigation annually until 2008 but rose to 29% (2013) and 32% (2014). Almost all multidrug-resistant 15A isolates were sequence type (ST) 63 variants, whereas susceptible 15A isolates were clonally diverse. The rise of serotype 15A suggests that pneumococcal conjugate vaccines will need ongoing adaptation. PMID:28006650

  11. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera)

    PubMed Central

    Snell, Terry W; Shearer, Tonya L; Smith, Hilary A; Kubanek, Julia; Gribble, Kristin E; Welch, David B Mark

    2009-01-01

    Background Mate choice is of central importance to most animals, influencing population structure, speciation, and ultimately the survival of a species. Mating behavior of male brachionid rotifers is triggered by the product of a chemosensory gene, a glycoprotein on the body surface of females called the mate recognition pheromone. The mate recognition pheromone has been biochemically characterized, but little was known about the gene(s). We describe the isolation and characterization of the mate recognition pheromone gene through protein purification, N-terminal amino acid sequence determination, identification of the mate recognition pheromone gene from a cDNA library, sequencing, and RNAi knockdown to confirm the functional role of the mate recognition pheromone gene in rotifer mating. Results A 29 kD protein capable of eliciting rotifer male circling was isolated by high-performance liquid chromatography. Two transcript types containing the N-terminal sequence were identified in a cDNA library; further characterization by screening a genomic library and by polymerase chain reaction revealed two genes belonging to each type. Each gene begins with a signal peptide region followed by nearly perfect repeats of an 87 to 92 codon motif with no codons between repeats and the final motif prematurely terminated by the stop codon. The two Type A genes contain four and seven repeats and the two Type B genes contain three and five repeats, respectively. Only the Type B gene with three repeats encodes a peptide with a molecular weight of 29 kD. Each repeat of the Type B gene products contains three asparagines as potential sites for N-glycosylation; there are no asparagines in the Type A genes. RNAi with Type A double-stranded RNA did not result in less circling than in the phosphate-buffered saline control, but transfection with Type B double-stranded RNA significantly reduced male circling by 17%. The very low divergence between repeat units, even at synonymous positions

  12. Cellulose-based diagnostic devices for diagnosing serotype-2 dengue fever in human serum.

    PubMed

    Wang, Hsi-Kai; Tsai, Cheng-Han; Chen, Kuan-Hung; Tang, Chung-Tao; Leou, Jiun-Shyang; Li, Pi-Chun; Tang, Yin-Liang; Hsieh, Hsyue-Jen; Wu, Han-Chung; Cheng, Chao-Min

    2014-02-01

    Here, two types of cellulose-based in vitro diagnostic devices are demonstrated for the diagnosis of dengue virus infection in both buffer system and human serum: 1) paper-based ELISA for providing the semiquantitative information of the disease activity of serotype-2 dengue fever to healthcare persons (i.e., monitoring the disease activity with a specific serotype in single patients); 2) lateral flow immunoassays to screen for infection with serotype-2 dengue fever (i.e., rapid YES or NO diagnosis prepared for large populations, in terms of global public health). Paper-based ELISA (specific to serotype-2 dengue fever), which builds off of our previous studies and a revised previous ELISA procedure, owns multiple advantages: 1) high sensitivity (about 40 times higher than the current ELISA-based approaches, due to our therapeutic-based monoclonal antibody) and specificity (specific to dengue virus serotype-2 nonstructural protein-1 antigens); 2) tiny amount of sample and reagent used for single tests; 3) short operating duration (i.e., rapid diagnostic device); and, 4) inexpensiveness (appropriate for use in all developing and underdeveloped nations of the world). Due to the higher sensitivity and shorter operating duration of paper-based ELISA (compared with conventional ELISA, and lateral flow immunoassays also performed in this study), this study has not only been able to perform the diagnosis of dengue virus serotype-2 nonstructural protein-1 antigens in both buffer system and human serum but also to evaluate dengue virus serotype-2 envelope proteins in the buffer system, thus successfully achieving the first such use of these proteins as the target antigen for the development of diagnostic tools. These results provide a more comprehensive understanding for the genesis of dengue fever diagnostic tools (through antibody-antigen recognition).

  13. Capsular serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae causing invasive pneumococcal disease from 2009-2012 with an emphasis on serotype 19A in bacteraemic pneumonia and empyema and β-lactam resistance.

    PubMed

    Lee, Meng-Rui; Chen, Chung-Ming; Chuang, Tzu-Yi; Huang, Yu-Tsung; Hsueh, Po-Ren

    2013-11-01

    Capsular serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae isolates that cause invasive pneumococcal disease (IPD) were studied and the role of serotype 19A in the development of bacteraemic pneumonia and empyema was investigated. Subjects comprised 98 patients (56 adults and 42 children) who were treated for IPD at a university-affiliated tertiary referral centre in Taiwan during 2009-2012. Serotypes of the isolates were identified using the latex agglutination method. In vitro susceptibilities of the isolates to 13 antimicrobial agents were determined using the broth microdilution method and were interpreted as recommended by the Clinical and Laboratory Standards Institute. During the study period, bacteraemic pneumonia was the most common type of infection (43/98; 43.9%), followed by primary bacteraemia (30/98; 30.6%). Serotype 19A was the most common serotype (23/98; 23.5%) in all patients. Fourteen (70.0%) of 20 children (47.6% of all children) with serotype 19A infection had pneumonia with empyema, whilst eight patients had concomitant bacteraemia. 7-valent pneumococcal conjugated vaccine (PCV-7), PCV-10, PCV-13 and 23-valent pneumococcal polysaccharide vaccine (PPV-23) had coverage rates of 37.8%, 38.8%, 79.6% and 77.6%, respectively. A substantial increase in the proportion of serotype 15A (6.1%) and 6A (8.2%) was found. In addition, there was a significant reduction in rates of susceptibility of serotype 19A isolates to penicillin, cefotaxime and ceftriaxone but not to azithromycin or any quinolone tested compared with those of non-19A isolates. The prevalence of serotypes 19A, 15A and 6A in patients with IPD increased markedly during the period, especially in children with bacteraemic pneumonia and empyema.

  14. Transmission dynamics of two dengue serotypes with vaccination scenarios.

    PubMed

    González Morales, N L; Núñez-López, M; Ramos-Castañeda, J; Velasco-Hernández, J X

    2016-10-20

    In this work we present a mathematical model that incorporates two Dengue serotypes. The model has been constructed to study both the epidemiological trends of the disease and conditions that allow coexistence in competing strains under vaccination. We consider two viral strains and temporary cross-immunity with one vector mosquito population. Results suggest that vaccination scenarios will not only reduce disease incidence but will also modify the transmission dynamics. Indeed, vaccination and cross immunity period are seen to decrease the frequency and magnitude of outbreaks but in a differentiated manner with specific effects depending upon the interaction vaccine and strain type.

  15. Putatively novel serotypes and the potential for reduced vaccine effectiveness: capsular locus diversity revealed among 5405 pneumococcal genomes

    PubMed Central

    van Tonder, Andries J.; Bray, James E.; Quirk, Sigríður J.; Haraldsson, Gunnsteinn; Jolley, Keith A.; Maiden, Martin C. J.; Hoffmann, Steen; Bentley, Stephen D.; Haraldsson, Ásgeir; Erlendsdóttir, Helga; Kristinsson, Karl G.; Brueggemann, Angela B.

    2017-01-01

    The pneumococcus is a leading global pathogen and a key virulence factor possessed by the majority of pneumococci is an antigenic polysaccharide capsule (‘serotype’), which is encoded by the capsular (cps) locus. Approximately 100 different serotypes are known, but the extent of sequence diversity within the cps loci of individual serotypes is not well understood. Investigating serotype-specific sequence variation is crucial to the design of sequence-based serotyping methodology, understanding pneumococcal conjugate vaccine (PCV) effectiveness and the design of future PCVs. The availability of large genome datasets makes it possible to assess population-level variation among pneumococcal serotypes and in this study 5405 pneumococcal genomes were used to investigate cps locus diversity among 49 different serotypes. Pneumococci had been recovered between 1916 and 2014 from people of all ages living in 51 countries. Serotypes were deduced bioinformatically, cps locus sequences were extracted and variation was assessed within the cps locus, in the context of pneumococcal genetic lineages. Overall, cps locus sequence diversity varied markedly: low to moderate diversity was revealed among serogroups/types 1, 3, 7, 9, 11 and 22; whereas serogroups/types 6, 19, 23, 14, 15, 18, 33 and 35 displayed high diversity. Putative novel and/or hybrid cps loci were identified among all serogroups/types apart from 1, 3 and 9. This study demonstrated that cps locus sequence diversity varied widely between serogroups/types. Investigation of the biochemical structure of the polysaccharide capsule of major variants, particularly PCV-related serotypes and those that appear to be novel or hybrids, is warranted. PMID:28133541

  16. Inline Electrical Connector Mate/Demate Pliers

    NASA Technical Reports Server (NTRS)

    Yutko, Brian; Dininny, Michael; Moscoso, Gerand; Dokos, Adam

    2010-01-01

    Military and aerospace industries use Mil-Spec type electrical connections on bulkhead panels that require inline access for mate and demate operations. These connectors are usually in tight proximity to other connectors, or recessed within panels. The pliers described here have been designed to work in such tight spaces, and consist of a mirrored set of parallel handles, two cross links, two return springs, and replaceable polyurethane-coated end effectors. The polyurethane eliminates metal-to-metal contact and provides a high-friction surface between the jaw and the connector. Operationally, the user would slide the pliers over the connector shell until the molded polyurethane lip makes contact with the connector shell edge. Then, by squeezing the handles, the end effector jaws grip the connector shell, allowing the connector to be easily disconnected by rotating the pliers. Mating the connector occurs by reversing the prescribed procedure, except the connector shell is placed into the jaws by hand. The molded lip within the jaw allows the user to apply additional force for difficult-to-mate connectors. Handle design has been carefully examined to maximize comfort, limit weight, incorporate tether locations, and improve ergonomics. They have been designed with an off-axis offset for wiring harness clearance, while placing the connector axis of rotation close to the user s axis of wrist rotation. This was done to eliminate fatigue during multiple connector panel servicing. To limit handle opening width, with user ergonomics in mind, the pliers were designed using a parallel jaw mechanism. A cross-link mechanism was used to complete this task, while ensuring smooth operation.

  17. Comparative evaluation and its implications for mate choice.

    PubMed

    Bateson, Melissa; Healy, Susan D

    2005-12-01

    Experiments on decision making by humans show that the choices that we make can be very labile. The magnitude of our preferences, and even our rank ordering of options, can vary according to the number and type of alternatives available for comparison. This apparent irrationality has been argued to result from our use of decision heuristics that have evolved to enable us to choose quickly and efficiently between options differing in multiple attributes. Here, we argue that, because there is also selective pressure for animals to make mating decisions quickly, and because potential mates also differ in multiple attributes, similar decision heuristics might have evolved for mate choice. Following this reasoning, the attractiveness of a given mate will depend on the others with whom he or she is being compared, rather than being an absolute function of his or her underlying quality. We describe some of the ramifications of such comparative evaluation, and argue that it could offer new insights into some of the biggest outstanding problems in mate choice and sexual selection.

  18. Assortative mating and spatial structure in hybrid zones.

    PubMed

    M'Gonigle, Leithen K; FitzJohn, Richard G

    2010-02-01

    The spatial genetic composition of hybrid zones exhibits a range of possible patterns, with many characterized by patchy distributions. While several hypothetical explanations exist for the maintenance of these "mosaic" hybrid zones, they remain virtually unexplored theoretically. Using computer simulations we investigate the roles of dispersal and assortative mating in the formation and persistence of hybrid zone structure. To quantify mosaic structure we develop a likelihood method, which we apply to simulation and empirical data. We find that long distance dispersal can lead to a patchy distribution that assortative mating can then reinforce, ultimately producing a mosaic capable of persisting over evolutionarily significant periods of time. By reducing the mating success of rare males, assortative mating creates a positive within-patch frequency-dependent selective pressure. Selection against heterozygotes can similarly create a rare-type disadvantage and we show that it can also preserve structure. We find that mosaic structure is maintained across a range of assumptions regarding the form and strength of assortative mating. Interestingly, we find that higher levels of mosaic structure are sometimes observed for intermediate assortment strengths. The high incidence of assortment documented in hybrid zones suggests that it may play a key role in stabilizing their form and structure.

  19. Polygyny, mate-guarding, and posthumous fertilization as alternative male mating strategies

    PubMed Central

    Zamudio, Kelly R.; Sinervo, Barry

    2000-01-01

    Alternative male mating strategies within populations are thought to be evolutionarily stable because different behaviors allow each male type to successfully gain access to females. Although alternative male strategies are widespread among animals, quantitative evidence for the success of discrete male strategies is available for only a few systems. We use nuclear microsatellites to estimate the paternity rates of three male lizard strategies previously modeled as a rock-paper-scissors game. Each strategy has strengths that allow it to outcompete one morph, and weaknesses that leave it vulnerable to the strategy of another. Blue-throated males mate-guard their females and avoid cuckoldry by yellow-throated “sneaker” males, but mate-guarding is ineffective against aggressive orange-throated neighbors. The ultradominant orange-throated males are highly polygynous and maintain large territories; they overpower blue-throated neighbors and cosire offspring with their females, but are often cuckolded by yellow-throated males. Finally, yellow-throated sneaker males sire offspring via secretive copulations and often share paternity of offspring within a female's clutch. Sneaker males sire more offspring posthumously, indicating that sperm competition may be an important component of their strategy. PMID:11106369

  20. Epidemiology of pneumococcal serotype 6A and 6C among invasive and carriage isolates from Alaska, 1986–2009☆

    PubMed Central

    Rudolph, Karen; Bruce, Michael; Bruden, Dana; Zulz, Tammy; Wenger, Jay; Reasonover, Alisa; Harker-Jones, Marcella; Hurlburt, Debby; Hennessy, Thomas

    2015-01-01

    We investigated serotype 6A/6C invasive pneumococcal disease (IPD) incidence, genetic diversity, and carriage before and after 7-valent pneumococcal conjugate vaccine (PCV7) introduction in Alaska. IPD cases (1986–2009) were identified through population-based laboratory surveillance. Isolates were initially serotyped by conventional methods, and 6C isolates were differentiated from 6A by polymerase chain reaction. Among invasive and carriage isolates initially typed as 6A, 35% and 50% were identified as 6C, respectively. IPD rates caused by serotype 6A or 6C among children <5 years did not change from the pre- to post-PCV7 period (P = 0.71 and P = 0.09, respectively). Multilocus sequence typing of IPD isolates revealed 28 sequence types. The proportion of serotype 6A carriage isolates decreased from 7.4% pre-PCV7 to 1.8% (P < 0.001) during 2008–2009; the proportion of serotype 6C carriage isolates increased from 3.0% to 8.4% (P = 0.004) among children <5 years. Continued surveillance is warranted to monitor changes in serotype distribution and prevalence. PMID:23276772

  1. Ondansetron can enhance cisplatin-induced nephrotoxicity via inhibition of multiple toxin and extrusion proteins (MATEs)

    SciTech Connect

    Li, Qing; Guo, Dong; Dong, Zhongqi; Zhang, Wei; Zhang, Lei; Huang, Shiew-Mei; Polli, James E.; Shu, Yan

    2013-11-15

    The nephrotoxicity limits the clinical application of cisplatin. Human organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATEs) work in concert in the elimination of cationic drugs such as cisplatin from the kidney. We hypothesized that co-administration of ondansetron would have an effect on cisplatin nephrotoxicity by altering the function of cisplatin transporters. The inhibitory potencies of ondansetron on metformin accumulation mediated by OCT2 and MATEs were determined in the stable HEK-293 cells expressing these transporters. The effects of ondansetron on drug disposition in vivo were examined by conducting the pharmacokinetics of metformin, a classical substrate for OCTs and MATEs, in wild-type and Mate1−/− mice. The nephrotoxicity was assessed in the wild-type and Mate1−/− mice received cisplatin with and without ondansetron. Both MATEs, including human MATE1, human MATE2-K, and mouse Mate1, and OCT2 (human and mouse) were subject to ondansetron inhibition, with much greater potencies by ondansetron on MATEs. Ondansetron significantly increased tissue accumulation and pharmacokinetic exposure of metformin in wild-type but not in Mate1−/− mice. Moreover, ondansetron treatment significantly enhanced renal accumulation of cisplatin and cisplatin-induced nephrotoxicity which were indicated by increased levels of biochemical and molecular biomarkers and more severe pathohistological changes in mice. Similar increases in nephrotoxicity were caused by genetic deficiency of MATE function in mice. Therefore, the potent inhibition of MATEs by ondansetron enhances the nephrotoxicity associated with cisplatin treatment in mice. Potential nephrotoxic effects of combining the chemotherapeutic cisplatin and the antiemetic 5-hydroxytryptamine-3 (5-HT{sub 3}) receptor antagonists, such as ondansetron, should be investigated in patients. - Highlights: • Nephrotoxicity significantly limits clinical use of the chemotherapeutic

  2. Spread of Streptococcus pneumoniae Serotype 8-ST63 Multidrug-Resistant Recombinant Clone, Spain

    PubMed Central

    de la Campa, Adela G.; García, Ernesto; Fenoll, Asunción; Calatayud, Laura; Cercenado, Emilia; Pérez-Trallero, Emilio; Bouza, Emilio; Liñares, Josefina

    2014-01-01

    Since 2004, a total of 131 isolates of Streptococcus pneumoniae multidrug-resistant invasive serotype 8 have been detected in Spain. These isolates showed resistance to erythromycin, clindamycin, tetracycline, and ciprofloxacin. All isolates were obtained from adult patients and shared a common genotype (sequence type [ST]63; penicillin-binding protein 1a [pbp1a], pbp2b, and pbp2x gene profiles; ermB and tetM genes; and a ParC-S79F change). Sixty-eight isolates that required a ciprofloxacin MIC ≥16 μg/mL had additional gyrA gene changes. Serotype 8-ST63 pbp2x sequences were identical with those of antimicrobial drug–susceptible serotype 8-ST53 isolates. Serotype 8-ST63 pbp2b sequences were identical with those of the multidrug-resistant Sweden 15A-ST63 clone. Recombination between the capsular locus and flanking regions of an ST53 isolate (donor) and an ST63 pneumococcus (recipient) generated the novel 15A-ST63 clone. One recombination point was upstream of pbp2x and another was within pbp1a. A serotype 8-ST63 clone was identified as a cause of invasive disease in Spain. PMID:25340616

  3. Serotype and genotype distribution among invasive Streptococcus pneumoniae isolates in Colombia, 2005-2010.

    PubMed

    Parra, Eliana L; Ramos, Viviana; Sanabria, Olga; Moreno, Jaime

    2014-01-01

    In Colombia, a laboratory-based surveillance of invasive Streptococcus pneumoniae isolates as part of SIREVA II PAHO has been conducted since 1994. This study describes the serotype distribution, antimicrobial resistance, and genetic relationships of pneumococcal isolates recovered in Colombia from 2005 to 2010. In this study, demographic data of invasive S. pneumoniae isolates were analyzed, and antimicrobial susceptibility patterns were determined. Pulse field gel electrophoresis (n = 629) and multilocus sequence typing (n = 10) were used to determine genetic relationship of isolates with minimal inhibitory concentration to penicillin ≥0.125 µg/mL. A total of 1775 isolates of S. pneumoniae were obtained. Fifteen serotypes accounted for 80.7% of isolates. Serotype 14 (23.1%) was the most frequent in the general population. Penicillin resistance was 30.7% in meningitis and 9.0% in non-meningitis. Clones Spain(6B)ST90, Spain(9V)ST156, Spain(23F)ST81, and Colombia(23F)ST338 were associated to isolates. Additionally, serotype 6A isolates were associated with ST460 and ST473, and 19A isolates with ST276, ST320, and ST1118. In conclusion, the surveillance program provided updated information of trends in serotype distribution, antimicrobial resistance and the circulation of clones in invasive pneumococcal diseases. These results could be helpful to understand the epidemiology of S. pneumoniae in Colombia, and provide a baseline to measure the impact of vaccine introduction.

  4. DC-SIGN specifically recognizes Streptococcus pneumoniae serotypes 3 and 14.

    PubMed

    Koppel, Estella A; Saeland, Eirikur; de Cooker, Désirée J M; van Kooyk, Yvette; Geijtenbeek, Teunis B H

    2005-01-01

    The Gram-positive bacterium Streptococcus pneumoniae is the leading causative pathogen in community-acquired pneumonia. The ever-increasing frequency of antibiotic-resistant S. pneumoniae strains severely hampers effective treatments. Thus, a better understanding of the mechanisms involved in the pathogenesis of pneumococcal disease is needed; in particular, of the initial interactions that take place between the host and the bacterium. Recognition of pathogens by dendritic cells is one of the most crucial steps in the induction of an immune response. For efficient pathogen recognition, dendritic cells express various kinds of receptors, including the DC-specific C-type lectin DC-SIGN. Pathogens such as Mycobacterium tuberculosis and HIV target DC-SIGN to escape immunity. Here the in vitro binding of DC-SIGN with S. pneumoniae was investigated. DC-SIGN specifically interacts with S. pneumoniae serotype 3 and 14 in contrast to other serotypes such as 19F. While the data described here suggest that DC-SIGN interacts with S. pneumoniae serotype 14 through a ligand expressed by the capsular polysaccharide, the binding to S. pneumoniae serotype 3 appears to depend on an as yet unidentified ligand. Despite the binding capacity of the capsular polysaccharide of S. pneumoniae 14 to DC-SIGN, no immunomodulatory effects on the dendritic cells were observed. The immunological consequences of the serotype-specific capacity to interact with DC-SIGN should be further explored and might result in new insights in the development of new and more potent vaccines.

  5. Serotype and Genotype Distribution among Invasive Streptococcus pneumoniae Isolates in Colombia, 2005–2010

    PubMed Central

    Parra, Eliana L.; Ramos, Viviana; Sanabria, Olga; Moreno, Jaime

    2014-01-01

    In Colombia, a laboratory-based surveillance of invasive Streptococcus pneumoniae isolates as part of SIREVA II PAHO has been conducted since 1994. This study describes the serotype distribution, antimicrobial resistance, and genetic relationships of pneumococcal isolates recovered in Colombia from 2005 to 2010. In this study, demographic data of invasive S. pneumoniae isolates were analyzed, and antimicrobial susceptibility patterns were determined. Pulse field gel electrophoresis (n = 629) and multilocus sequence typing (n = 10) were used to determine genetic relationship of isolates with minimal inhibitory concentration to penicillin ≥0.125 µg/mL. A total of 1775 isolates of S. pneumoniae were obtained. Fifteen serotypes accounted for 80.7% of isolates. Serotype 14 (23.1%) was the most frequent in the general population. Penicillin resistance was 30.7% in meningitis and 9.0% in non-meningitis. Clones Spain6BST90, Spain9VST156, Spain23FST81, and Colombia23FST338 were associated to isolates. Additionally, serotype 6A isolates were associated with ST460 and ST473, and 19A isolates with ST276, ST320, and ST1118. In conclusion, the surveillance program provided updated information of trends in serotype distribution, antimicrobial resistance and the circulation of clones in invasive pneumococcal diseases. These results could be helpful to understand the epidemiology of S. pneumoniae in Colombia, and provide a baseline to measure the impact of vaccine introduction. PMID:24416330

  6. Cloning of a novel constitutively expressed pectate lyase gene pelB from Fusarium solani f. sp. pisi (Nectria haematococca, mating type VI) and characterization of the gene product expressed in Pichia pastoris.

    PubMed Central

    Guo, W; González-Candelas, L; Kolattukudy, P E

    1995-01-01

    Since plant-pathogenic fungi must penetrate through pectinaceous layers of the host cell wall, pectin-degrading enzymes are thought to be important for pathogenesis. Antibodies prepared against a pectin-inducible pectate lyase (pectate lyase A [PLA]) produced by a phytopathogenic fungus, Fusarium solani f. sp. pisi (Nectria haematococca, mating type VI), was previously found to protect the host from infection. The gene (pelA) and its cDNA were cloned and sequenced. Here we report the isolation of a new pectate lyase gene, pelB, from a genomic library of F. solani f. sp. pisi with the pelA cDNA as the probe. A 2.6-kb DNA fragment containing pelB and its flanking regions was sequenced. The coding region of pelB was amplified by reverse transcription-mediated PCR, using total RNA isolated from F. solani pisi culture grown in the presence of glucose as the sole carbon source. The predicted open reading frame of pelB would encode a 25.6-kDa protein of 244 amino acids which has 65% amino acid sequence identity with PLA from F. solani f. sp. pisi but no significant homology with other pectinolytic enzymes. The first 16 amino acid residues at the N terminus appeared to be a signal peptide. The pelB cDNA was expressed in Pichia pastoris, yielding a pectate lyase B (PLB) which was found to be a glycoprotein of 29 kDa. PLB was purified to homogeneity by using a two-step procedure involving ammonium sulfate precipitation followed by Superdex G75 gel filtration chromatography. Purified PLB showed optimal lyase activity at pH 10.0. A rapid drop in the viscosity of the substrate and Mono Q anion-exchange chromatography of the products generated by the lyase showed that PLB cleaved polygalacturonate chains in an endo fashion. Western blotting (immunoblotting) with antibodies raised against PLA showed that PLB and PLA are immunologically related to each other. The 5' flanking regions of both pelA and pelB were translationally fused to the beta-glucuronidase gene and introduced into

  7. Density affects mating mode and large male mating advantage in a fiddler crab.

    PubMed

    Ribeiro, Pablo D; Daleo, Pedro; Iribarne, Oscar O

    2010-12-01

    Fiddler crabs show two different mating modes: either females search and crabs mate underground in male burrows, or males search and crabs mate on the surface near female burrows. We explored the relationship between crab density, body size, the searching behavior of both sexes, and the occurrence of both mating modes in the fiddler crab Uca uruguayensis. We found that crabs change their mating mode depending on their size and crab density. Crabs mated mostly on the surface at low densities, and underground at high densities. The proportion of wandering receptive females but not courting males accounted for the variation in mating modes. This suggests that whether crabs mate underground (or on the surface) is determined by the presence (or absence) of searching females. We found that the change in the mating mode affected the level of assortative mating; males mating underground were bigger than those mating on the surface, suggesting active female choice. Given that fiddler crabs experience multiple reproductive cycles, they are prone to showing behavioral plasticity in their mating strategy whenever the payoffs of using different mating modes differ between reproductive events. Our results suggest that the incorporation of different levels of environmental variability may be important in theoretical models aimed at improving our understanding of the evolution of alternative mating tactics and strategies.

  8. Novel serotype of bluetongue virus, western North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bluetongue virus serotypes 10, 11, 13, and 17 are typically found throughout the United States (US), while serotype 2 was previously only detected in the southeastern US. In 2010, serotype 2 was identified in California for the first time and preliminary sequences analysis indicated that the virus ...

  9. Application of Whole-Genome Sequencing Data for O-Specific Antigen Analysis and In Silico Serotyping of Pseudomonas aeruginosa Isolates

    PubMed Central

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Lund, Ole

    2016-01-01

    Accurate typing methods are required for efficient infection control. The emergence of whole-genome sequencing (WGS) technologies has enabled the development of genome-based methods applicable for routine typing and surveillance of bacterial pathogens. In this study, we developed the Pseudomonas aeruginosa serotyper (PAst) program, which enabled in silico serotyping of P. aeruginosa isolates using WGS data. PAst has been made publically available as a web service and aptly facilitates high-throughput serotyping analysis. The program overcomes critical issues such as the loss of in vitro typeability often associated with P. aeruginosa isolates from chronic infections and quickly determines the serogroup of an isolate based on the sequence of the O-specific antigen (OSA) gene cluster. Here, PAst analysis of 1,649 genomes resulted in successful serogroup assignments in 99.27% of the cases. This frequency is rarely achievable by conventional serotyping methods. The limited number of nontypeable isolates found using PAst was the result of either a complete absence of OSA genes in the genomes or the artifact of genomic misassembly. With PAst, P. aeruginosa serotype data can be obtained from WGS information alone. PAst is a highly efficient alternative to conventional serotyping methods in relation to outbreak surveillance of serotype O12 and other high-risk clones, while maintaining backward compatibility to historical serotype data. PMID:27098958

  10. Mating behavior of Diabrotica speciosa (Coleoptera: Chrysomelidae).

    PubMed

    Nardi, C; Luvizotto, R A; Parra, J R P; Bento, J M S

    2012-06-01

    Diabrotica speciosa (Germar) is an economically important pest of Neotropical cultures and represents a quarantine risk for Neartic and Paleartic Regions. Despite its agricultural importance, few studies have been done on mating behavior and chemical communication, which has delayed the development of behavioral techniques for population management, such as the use of pheromone traps. In this study, we determined 1) the age at first mating; 2) diel rhythm of matings; 3) number of matings over 7 d; 4) the sequence of D. speciosa activities during premating, mating, and postmating; 5) the duration of each activity; and 6) response to male and female conspecific volatiles in Y-tube olfactometer. The first mating occurred between the third and seventh day after adult emergence and the majority of pairs mated on the fourth day after emergence. Pairs of D. speciosa showed a daily rhythm of mating with greater sexual activity between the end of the photophase and the first half of the scotophase. During the 7 d of observation, most pairs mated only once, although 30% mated two, three, or four times. In a Y-tube olfactometer, males were attracted by virgin females as well as by the volatile compounds emitted by females. Neither males nor their volatiles were attractive to either sex. Our observation provide information about mating behavior of D. speciosa, which will be useful in future research in chemical communication, such as identification of the pheromone and development of management techniques for this species using pheromone traps.

  11. Haemophilus influenzae serotype a as a cause of serious invasive infections.

    PubMed

    Ulanova, Marina; Tsang, Raymond S W

    2014-01-01

    Haemophilus influenzae, particularly H influenzae serotype b (Hib), is an important pathogen that causes serious diseases like meningitis and septicaemia. Since the introduction of Hib conjugate vaccines in the 1990s, the epidemiology of invasive H influenzae disease has changed substantially, with most infections now caused by non-Hib strains. We discuss the importance of H influenzae serotype a (Hia) as a cause of serious morbidity and mortality and its global epidemiology, clinical presentation, microbiology, immunology, prevention, and control. Much like Hib, the capsule of Hia is an important virulence factor contributing to the development of invasive disease. Molecular typing of Hia has identified distinct clonal groups, with some linked to severe disease and high case-fatality rates. Similarities between Hia and Hib capsules, their clinical presentation, and immunology of infection suggest that a bivalent Hia-Hib capsular polysaccharide-protein conjugate vaccine could offer protection against these two important serotypes of H influenzae.

  12. Meningitis due to Haemophilus influenzae type f.

    PubMed

    Cardoso, Marta Pessoa; Pasternak, Jacyr; Giglio, Alfredo Elias; Casagrande, Rejane Rimazza Dalberto; Troster, Eduardo Juan

    2013-12-01

    With the decline in the rate of infections caused by Haemophilus influenzae serotype b since the widespread vaccination, non-b serotypes should be considered as potential pathogenic agents in children with invasive disease younger than 5 years old. We report the case of an immunocompetent 1-year-old boy with Haemophilus influenzae type f meningitis. The agent was identified in cerebrospinal fluid and blood cultures. Serotyping was performed by tests using polyclonal sera and confirmed by polymerase chain reaction. All Haemophilus influenzae isolates associated with invasive disease should be serotyped and notified as a way to evaluate the changes and trends in serotype distribution of this disease.

  13. Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk

    NASA Astrophysics Data System (ADS)

    Fowler-Finn, Kasey D.; Al-Wathiqui, Nooria; Cruz, Daniel; Al-Wathiqui, Mishal; Rodríguez, Rafael L.

    2014-03-01

    Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers—a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators.

  14. Saccharomyces cerevisiae cells execute a default pathway to select a mate in the absence of pheromone gradients

    PubMed Central

    1995-01-01

    During conjugation, haploid S. cerevisiae cells find one another by polarizing their growth toward each other along gradients of pheromone (chemotropism). We demonstrate that yeast cells exhibit a second mating behavior: when their receptors are saturated with pheromone, wild-type a cells execute a default pathway and select a mate at random. These matings are less efficient than chemotropic matings, are induced by the same dose of pheromone that induces shmoo formation, and appear to use a site near the incipient bud site for polarization. We show that the SPA2 gene is specifically required for the default pathway: spa2 delta mutants cannot mate if pheromone concentrations are high and gradients are absent, but can mate if gradients are present. ste2 delta, sst2 delta, and far1 delta mutants are chemotropism-defective and therefore must choose a mate by using a default pathway; consistent with this deduction, these strains require SPA2 to mate. In addition, our results suggest that far1 mutants are chemotropism-defective because their mating polarity is fixed at the incipient bud site, suggesting that the FAR1 gene is required for inhibiting the use of the incipient bud site during chemotropic mating. These observations reveal a molecular relationship between the mating and budding polarity pathways. PMID:7490289

  15. Mated vertical ground vibration test

    NASA Technical Reports Server (NTRS)

    Ivey, E. W.

    1980-01-01

    The Mated Vertical Ground Vibration Test (MVGVT) was considered to provide an experimental base in the form of structural dynamic characteristics for the shuttle vehicle. This data base was used in developing high confidence analytical models for the prediction and design of loads, pogo controls, and flutter criteria under various payloads and operational missions. The MVGVT boost and launch program evolution, test configurations, and their suspensions are described. Test results are compared with predicted analytical results.

  16. Not what it looks like: mate-searching behaviour, mate preferences and clutch production in wandering and territory-holding female fiddler crabs

    PubMed Central

    Curran, E.; Backwell, P. R. Y.

    2016-01-01

    Risks inherent in mate-searching have led to the assumption that females moving sequentially through populations of courting males are sexually receptive, but this may not be true. We examined two types of fiddler crab females: wanderers moving through the population of courting males and residents that were occupying and defending their own territories. Sometimes residents leave territories to look for new burrows and we simulated this by displacing wanderers and residents and observing their behaviour while wandering. We predicted that the displaced wanderers would exhibit more mate-searching behaviours than resident females. However, wandering and resident females behaved nearly identically, displaying mate-searching behaviours and demonstrating matching mate preferences. Also, males behaved the same way towards both female types and similar proportions of wanderers and residents stayed in a male's burrow to mate. But more wanderers than residents produced egg clutches when choosing a burrow containing a male, suggesting females should be categorized as receptive and non-receptive. Visiting and rejecting several males is not the defining feature of female mate choice. Moving across the mudflat by approaching and leaving a succession of burrows (mostly occupied by males) is an adaptive anti-predator behaviour that is useful in the contexts of mate-searching and territory-searching. PMID:27853615

  17. Not what it looks like: mate-searching behaviour, mate preferences and clutch production in wandering and territory-holding female fiddler crabs.

    PubMed

    Peso, M; Curran, E; Backwell, P R Y

    2016-08-01

    Risks inherent in mate-searching have led to the assumption that females moving sequentially through populations of courting males are sexually receptive, but this may not be true. We examined two types of fiddler crab females: wanderers moving through the population of courting males and residents that were occupying and defending their own territories. Sometimes residents leave territories to look for new burrows and we simulated this by displacing wanderers and residents and observing their behaviour while wandering. We predicted that the displaced wanderers would exhibit more mate-searching behaviours than resident females. However, wandering and resident females behaved nearly identically, displaying mate-searching behaviours and demonstrating matching mate preferences. Also, males behaved the same way towards both female types and similar proportions of wanderers and residents stayed in a male's burrow to mate. But more wanderers than residents produced egg clutches when choosing a burrow containing a male, suggesting females should be categorized as receptive and non-receptive. Visiting and rejecting several males is not the defining feature of female mate choice. Moving across the mudflat by approaching and leaving a succession of burrows (mostly occupied by males) is an adaptive anti-predator behaviour that is useful in the contexts of mate-searching and territory-searching.

  18. Rapid Molecular Determination of Serotype from Clinical Isolates of Salmonella Enterica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The conventional serotyping of Salmonella Enterica is time consuming, costly, and requires highly skilled staff. In the present study, we report a multiplex PCR typing method using capillary electrophoresis for fragment analysis that allows for the identification of the 30 most common h...

  19. Genomic Sequence of Campylobacter jejuni subsp. jejuni HS:19 Penner Serotype Reference Strain RM3420

    PubMed Central

    Huynh, Steven; Heikema, Astrid P.

    2017-01-01

    ABSTRACT Campylobacter jejuni subsp. jejuni infections are a leading cause of foodborne gastroenteritis and the most prevalent antecedent to Guillain-Barré syndrome (GBS). Penner serotype HS:19 is among several capsular types shown to be markers for GBS. This study describes the genome of C. jejuni subsp. jejuni HS:19 Penner reference strain RM3420. PMID:28232429

  20. Development of a rapid serotyping method for Salmonella enterica using serotype-specific single-nucleotide polymorphisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide, including the USA. Many S. enterica serotypes known to cause foodborne disease are associated with broiler meat contamination. While some serotypes are specific to birds (S. e...

  1. Whole genome sequencing of Streptococcus pneumoniae: development, evaluation and verification of targets for serogroup and serotype prediction using an automated pipeline

    PubMed Central

    Al-Shahib, Ali; Litt, David J.; Underwood, Anthony P.; Harrison, Timothy G.; Fry, Norman K.

    2016-01-01

    Streptococcus pneumoniae typically express one of 92 serologically distinct capsule polysaccharide (cps) types (serotypes). Some of these serotypes are closely related to each other; using the commercially available typing antisera, these are assigned to common serogroups containing types that show cross-reactivity. In this serotyping scheme, factor antisera are used to allocate serotypes within a serogroup, based on patterns of reactions. This serotyping method is technically demanding, requires considerable experience and the reading of the results can be subjective. This study describes the analysis of the S. pneumoniae capsular operon genetic sequence to determine serotype distinguishing features and the development, evaluation and verification of an automated whole genome sequence (WGS)-based serotyping bioinformatics tool, PneumoCaT (Pneumococcal Capsule Typing). Initially, WGS data from 871 S. pneumoniae isolates were mapped to reference cps locus sequences for the 92 serotypes. Thirty-two of 92 serotypes could be unambiguously identified based on sequence similarities within the cps operon. The remaining 60 were allocated to one of 20 ‘genogroups’ that broadly correspond to the immunologically defined serogroups. By comparing the cps reference sequences for each genogroup, unique molecular differences were determined for serotypes within 18 of the 20 genogroups and verified using the set of 871 isolates. This information was used to design a decision-tree style algorithm within the PneumoCaT bioinformatics tool to predict to serotype level for 89/94 (92 + 2 molecular types/subtypes) from WGS data and to serogroup level for serogroups 24 and 32, which currently comprise 2.1% of UK referred, invasive isolates submitted to the National Reference Laboratory (NRL), Public Health England (June 2014–July 2015). PneumoCaT was evaluated with an internal validation set of 2065 UK isolates covering 72/92 serotypes, including 19 non-typeable isolates and an

  2. Whole genome sequencing of Streptococcus pneumoniae: development, evaluation and verification of targets for serogroup and serotype prediction using an automated pipeline.

    PubMed

    Kapatai, Georgia; Sheppard, Carmen L; Al-Shahib, Ali; Litt, David J; Underwood, Anthony P; Harrison, Timothy G; Fry, Norman K

    2016-01-01

    Streptococcus pneumoniae typically express one of 92 serologically distinct capsule polysaccharide (cps) types (serotypes). Some of these serotypes are closely related to each other; using the commercially available typing antisera, these are assigned to common serogroups containing types that show cross-reactivity. In this serotyping scheme, factor antisera are used to allocate serotypes within a serogroup, based on patterns of reactions. This serotyping method is technically demanding, requires considerable experience and the reading of the results can be subjective. This study describes the analysis of the S. pneumoniae capsular operon genetic sequence to determine serotype distinguishing features and the development, evaluation and verification of an automated whole genome sequence (WGS)-based serotyping bioinformatics tool, PneumoCaT (Pneumococcal Capsule Typing). Initially, WGS data from 871 S. pneumoniae isolates were mapped to reference cps locus sequences for the 92 serotypes. Thirty-two of 92 serotypes could be unambiguously identified based on sequence similarities within the cps operon. The remaining 60 were allocated to one of 20 'genogroups' that broadly correspond to the immunologically defined serogroups. By comparing the cps reference sequences for each genogroup, unique molecular differences were determined for serotypes within 18 of the 20 genogroups and verified using the set of 871 isolates. This information was used to design a decision-tree style algorithm within the PneumoCaT bioinformatics tool to predict to serotype level for 89/94 (92 + 2 molecular types/subtypes) from WGS data and to serogroup level for serogroups 24 and 32, which currently comprise 2.1% of UK referred, invasive isolates submitted to the National Reference Laboratory (NRL), Public Health England (June 2014-July 2015). PneumoCaT was evaluated with an internal validation set of 2065 UK isolates covering 72/92 serotypes, including 19 non-typeable isolates and an external

  3. Dengue virus serotype 4, northeastern Peru, 2008.

    PubMed

    Forshey, Brett M; Morrison, Amy C; Cruz, Cristhopher; Rocha, Claudio; Vilcarromero, Stalin; Guevara, Carolina; Camacho, Daria E; Alava, Araceli; Madrid, César; Beingolea, Luis; Suarez, Victor; Comach, Guillermo; Kochel, Tadeusz J

    2009-11-01

    In 2008, dengue virus serotype 4 (DENV-4) emerged in northeastern Peru, causing a large outbreak and displacing DENV-3, which had predominated for the previous 6 years. Phylogenetic analysis of 2008 and 2009 isolates support their inclusion into DENV-4 genotype II, forming a lineage distinct from strains that had previously circulated in the region.

  4. Neutralization Serotyping of BK Polyomavirus Infection in Kidney Transplant Recipients

    PubMed Central

    Pastrana, Diana V.; Brennan, Daniel C.; Çuburu, Nicolas; Storch, Gregory A.; Viscidi, Raphael P.; Randhawa, Parmjeet S.; Buck, Christopher B.

    2012-01-01

    BK polyomavirus (BKV or BKPyV) associated nephropathy affects up to 10% of kidney transplant recipients (KTRs). BKV isolates are categorized into four genotypes. It is currently unclear whether the four genotypes are also serotypes. To address this issue, we developed high-throughput serological assays based on antibody-mediated neutralization of BKV genotype I and IV reporter vectors (pseudoviruses). Neutralization-based testing of sera from mice immunized with BKV-I or BKV-IV virus-like particles (VLPs) or sera from naturally infected human subjects revealed that BKV-I specific serum antibodies are poorly neutralizing against BKV-IV and vice versa. The fact that BKV-I and BKV-IV are distinct serotypes was less evident in traditional VLP-based ELISAs. BKV-I and BKV-IV neutralization assays were used to examine BKV type-specific neutralizing antibody responses in KTRs at various time points after transplantation. At study entry, sera from 5% and 49% of KTRs showed no detectable neutralizing activity for BKV-I or BKV-IV neutralization, respectively. By one year after transplantation, all KTRs were neutralization seropositive for BKV-I, and 43% of the initially BKV-IV seronegative subjects showed evidence of acute seroconversion for BKV-IV neutralization. The results suggest a model in which BKV-IV-specific seroconversion reflects a de novo BKV-IV infection in KTRs who initially lack protective antibody responses capable of neutralizing genotype IV BKVs. If this model is correct, it suggests that pre-vaccinating prospective KTRs with a multivalent VLP-based vaccine against all BKV serotypes, or administration of BKV-neutralizing antibodies, might offer protection against graft loss or dysfunction due to BKV associated nephropathy. PMID:22511874

  5. Pasteurella multocida serotype 1 isolated from a lesser snow goose

    USGS Publications Warehouse

    Samuel, M.D.; Goldberg, D.R.; Shadduck, D.J.; Price, J.I.; Cooch, E.G.

    1997-01-01

    Pharyngeal swabs were collected from 298 lesser snow geese (Chen caerulescens caerulescens) at Banks Island (Northwest Territories. Canada) in the summer of 1994. Pasteurella multocida serotype 1 was isolated from an adult male bird and P. multocida serotype 3 was isolated from an adult female goose. Pathogenicity of the serotype 1 isolate was confirmed by inoculation in Pekin ducks (Anas platyrhynchos). The serotype 3 isolate was non-pathogenic in Pekin ducks. This is the first documented isolation of pathogenic P. multocida serotype 1 from apparently healthy wild snow geese.

  6. MFα1, the Gene Encoding the α Mating Pheromone of Candida albicans†

    PubMed Central

    Panwar, Sneh L.; Legrand, Melanie; Dignard, Daniel; Whiteway, Malcolm; Magee, Paul. T.

    2003-01-01

    Candida albicans, the single most frequently isolated human fungal pathogen, was thought to be asexual until the recent discovery of the mating-type-like locus (MTL). Homozygous MTL strains were constructed and shown to mate. Furthermore, it has been demonstrated that opaque-phase cells are more efficient in mating than white-phase cells. The similarity of the genes involved in the mating pathway in Saccharomyces cerevisiae and C. albicans includes at least one gene (KEX2) that is involved in the processing of the α mating pheromone in the two yeasts. Taking into account this similarity, we searched the C. albicans genome for sequences that would encode the α pheromone gene. Here we report the isolation and characterization of the gene MFα1, which codes for the precursor of the α mating pheromone in C. albicans. Two active α-peptides, 13 and 14 amino acids long, would be generated after the precursor molecule is processed in C. albicans. To examine the role of this gene in mating, we constructed an mfα1 null mutant of C. albicans. The mfα1 null mutant fails to mate as MTLα, while MTLa mfα1 cells are still mating competent. Experiments performed with the synthetic α-peptides show that they are capable of inducing growth arrest, as demonstrated by halo tests, and also induce shmooing in MTLa cells of C. albicans. These peptides are also able to complement the mating defect of an MTLα kex2 mutant strain when added exogenously, thereby confirming their roles as α mating pheromones. PMID:14665468

  7. Distribution of serotypes of human rotavirus in different populations.

    PubMed Central

    Woods, P A; Gentsch, J; Gouvea, V; Mata, L; Santosham, M; Bai, Z S; Urasawa, S; Glass, R I

    1992-01-01

    Serotyping is a useful tool to study the epidemiologic characteristics of rotaviruses in large populations and to assess the need for a vaccine to protect against all strains. By using an enzyme immunoassay with serotype-specific monoclonal antibodies to the four most common rotavirus serotypes, we analyzed 1,183 rotavirus-positive specimens from 16 stool collections in eight countries on four continents that were obtained from 1978 to 1989. Of the 926 strains (78%) that could be serotyped, 48% were serotype 1, 8% were serotype 2, 15% were serotype 3, and 7% were serotype 4. Twenty-two percent had insufficient numbers of double-shelled virus particles to react with the monoclonal antibody of the VP4 rotavirus protein and therefore could not be serotyped. Our results indicate that vaccines being developed must provide the greatest coverage against serotype 1 and that the serotype distribution cannot be predicted currently by the geographic area or prevalence in the preceding year. PMID:1315333

  8. Female mate choice across mating stages and between sequential mates in flour beetles.

    PubMed

    Fedina, T Y; Lewis, S M

    2007-11-01

    Few studies have examined how female premating choice correlates with the outcome of copulatory and post-copulatory processes. It has been shown that polyandrous Tribolium castaneum females discriminate among males before mating based on olfactory cues, and also exert cryptic choice during mating through several mechanisms. This study tested whether a male's relative attractiveness predicted his insemination success during copulation. Bioassays with male olfactory cues were used to rank two males as more and less attractive to females; each female was then mated to either her more attractive male followed by less attractive male, or vice versa. Dissections immediately after second copulations revealed a significantly higher percent of successful inseminations for females that remated with more attractive males compared with those that remated with less attractive males. These results indicate that cryptic female choice during copulation reinforces precopulatory female choice in T. castaneum, and suggest that females could use cryptic choice to trade up to more attractive males, possibly gaining better phenotypic or genetic quality of sires.

  9. Revisiting telegony: offspring inherit an acquired characteristic of their mother's previous mate

    PubMed Central

    Crean, Angela J; Kopps, Anna M; Bonduriansky, Russell; Marshall, Dustin

    2014-01-01

    Newly discovered non-genetic mechanisms break the link between genes and inheritance, thereby also raising the possibility that previous mating partners could influence traits in offspring sired by subsequent males that mate with the same female (‘telegony’). In the fly Telostylinus angusticollis, males transmit their environmentally acquired condition via paternal effects on offspring body size. We manipulated male condition, and mated females to two males in high or low condition in a fully crossed design. Although the second male sired a large majority of offspring, offspring body size was influenced by the condition of the first male. This effect was not observed when females were exposed to the first male without mating, implicating semen-mediated effects rather than female differential allocation based on pre-mating assessment of male quality. Our results reveal a novel type of transgenerational effect with potential implications for the evolution of reproductive strategies. PMID:25270393

  10. Partitioning the effects of spatial isolation, nest habitat, and individual diet in causing assortative mating within a population of threespine stickleback.

    PubMed

    Snowberg, L K; Bolnick, D I

    2012-11-01

    Assortative mating is measured as a phenotypic or genotypic correlation between mates. Although biologists typically view assortative mating in terms of mate preference for similar partners, correlations between mates can also arise from phenotypic spatial structure arising from spatial isolation or habitat preferences. Here, we test whether diet-assortative mating within an ecologically variable population of threespine stickleback results from small-scale geographic isolation or microhabitat preference. We find evidence for assortative mating in the form of a positive correlation between mated pairs' diets (measured using stable isotopes). Stable isotopes reveal diet differences between different nesting areas and among individuals using different nest habitat within a nesting area. This spatial segregation of diet types should generate some assortative mating, but is insufficient to explain the observed assortment strength. Significant male-female isotope correlations remain after controlling for spatial variables. We therefore conclude that sticklebacks' diet-assortative mating arises from additional behavioral preference. More generally, our results illustrate the point that spatial segregation can only drive appreciable levels of phenotypic assortative mating when environment-phenotype correlations are parallel and strong in both sexes. Consequently, intraspecific assortative mating may typically entail mating preferences rather than just spatial cosegregation of phenotypes.

  11. Mating order-dependent female mate choice in the polygynandrous common lizard Lacerta vivipara.

    PubMed

    Fitze, Patrick S; Cote, Julien; Clobert, Jean

    2010-02-01

    Recent studies indicate that directional female mate choice and order-dependent female mate choice importantly contribute to non-random mating patterns. In species where females prefer larger sized males, disentangling different hypotheses leading to non-random mating patterns is especially difficult, given that male size usually correlates with behaviours that may lead to non-random mating (e.g. size-dependent emergence from hibernation, male fighting ability). Here we investigate female mate choice and order-dependent female mate choice in the polygynandrous common lizard (Lacerta vivipara). By sequentially presenting males in random order to females, we exclude non-random mating patterns potentially arising due to intra-sexual selection (e.g. male-male competition), trait-dependent encounter probabilities, trait-dependent conspicuousness, or trait-dependent emergence from hibernation. To test for order-dependent female mate choice we investigate whether the previous mating history affects female choice. We show that body size and body condition of the male with which a female mated for the first time were bigger and better, respectively, than the average body size and body condition of the rejected males. There was a negative correlation between body sizes of first and second copulating males. This indicates that female mate choice is dependent on the previous mating history and it shows that the female's choice criteria are non-static, i.e. non-directional. Our study therefore suggests that context-dependent female mate choice may not only arise due to genotype-environment interactions, but also due to other female mating strategies, i.e. order-dependent mate choice. Thus context-dependent female mate choice might be more frequent than previously thought.

  12. The interactive effects of herbivory and mixed mating for the population dynamics of Impatiens capensis.

    PubMed

    Steets, Janette A; Knight, Tiffany M; Ashman, Tia-Lynn

    2007-07-01

    In this study, we examine the demographic consequences of mixed mating and explore the interactive effects of vegetative herbivory and mating system for population dynamics of Impatiens capensis, a species with an obligate mixed mating system (i.e., individuals produce both obligately selfing cleistogamous and facultatively outcrossing chasmogamous flowers). In two natural populations, we followed seeds derived from cleistogamous and chasmogamous flowers subject to different herbivory levels throughout their life cycle. Using a mating system-explicit projection matrix model, we found that mating system types differed in important vital rates. Cleistogamous individuals had higher rates of germination than did chasmogamous individuals, whereas chasmogamous individuals expressed a fecundity advantage over cleistogamous individuals. In addition, population growth was most sensitive to changes in vital rates of cleistogamous individuals, indicating the demographic importance of selfing for these populations. Herbivory also had demographic consequences; a 33%-49% reduction in herbivory caused the population growth rates to increase by 104%-132%, primarily because of effects on vital rates of selfed individuals. Our results not only uncover a novel consequence of mating system expression, that is, mating system influences population dynamics, but also shed light on the role of herbivores in maintaining mixed mating.

  13. Prior mating success can affect allocation towards future sexual signaling in crickets

    PubMed Central

    Chiswell, Rachel; Girard, Madeline; Fricke, Claudia

    2014-01-01

    Fitness is often correlated with the expression level of a sexually selected trait. However, sexually selected traits are costly to express such that investment in their expression should be optimised to maximize their overall fitness gains. Social interactions, in the form of successful and unsuccessful matings, may offer males one type of feedback allowing them to gauge how to allocate their resources towards sexual signaling. Here we tested whether adult male black field crickets (Teleogryllus commodus) modify the extent of their calling effort (the sexually selected trait) in response to successful and unsuccessful matings with females. To examine the effect that mating interactions with females have on investment into sexual signaling, we monitored male calling effort after maturation and then provided males with a female at two points within their life, manipulating whether or not males were able to successfully mate each time. Our results demonstrate that males alter their investment towards sexual signaling in response to successful matings, but only if the experience occurs early in their life. Males that mated early decreased their calling effort sooner than males that were denied a mating. Our results demonstrate that social feedback in the form of successful and unsuccessful matings has the potential to alter the effort a male places towards sexual signaling. PMID:25392758

  14. Evolutionarily stable mating decisions for sequentially searching females and the stability of reproductive isolation by assortative mating.

    PubMed

    Priklopil, Tadeas; Kisdi, Eva; Gyllenberg, Mats

    2015-04-01

    We consider mating strategies for females who search for males sequentially during a season of limited length. We show that the best strategy rejects a given male type if encountered before a time-threshold but accepts him after. For frequency-independent benefits, we obtain the optimal time-thresholds explicitly for both discrete and continuous distributions of males, and allow for mistakes being made in assessing the correct male type. When the benefits are indirect (genes for the offspring) and the population is under frequency-dependent ecological selection, the benefits depend on the mating strategy of other females as well. This case is particularly relevant to speciation models that seek to explore the stability of reproductive isolation by assortative mating under frequency-dependent ecological selection. We show that the indirect benefits are to be quantified by the reproductive values of couples, and describe how the evolutionarily stable time-thresholds can be found. We conclude with an example based on the Levene model, in which we analyze the evolutionarily stable assortative mating strategies and the strength of reproductive isolation provided by them.

  15. Circulation of Dengue Virus Serotypes in the City of Makkah, Saudi Arabia, as Determined by Reverse Transcription Polymerase Chain Reaction

    PubMed Central

    Organji, Sameer R.; Osman, Gamal E. H.

    2017-01-01

    The present study was aimed to investigate the circulation of four dengue virus (DENV) serotypes in Makkah, Western Saudi Arabia. Blood samples were collected from 25 dengue fever-suspected patients and were subjected to molecular typing for DENV-1, DENV-2, DENV-3, and DENV-4 serotypes of dengue virus, by reverse transcription polymerase chain reaction (RT-PCR), using six sets of primers. Of the 25 samples, only six samples (24%) were found to be positive for dengue virus infection. The prevalence of DENV-1 was higher (50% of DENV-positive samples), as compared to DENV-2 (33.3%) and DENV-3 (16.6%) serotypes. The fourth serotype, DENV-4, was not detected in any of the DENV-positive samples. Although Makkah is considered endemic to dengue fever, we observed low prevalence of dengue virus in the city, which may be attributed to various factors. Nonetheless, the results presented herein confirm the circulation of DENV serotypes in the Western region of Saudi Arabia. To the best of our knowledge, the current study so far is the first report demonstrating the prevalence of the DENV-1 serotype in the city Makkah, Saudi Arabia. PMID:28298933

  16. Emerging resistant serotypes of invasive Streptococcus pneumoniae

    PubMed Central

    Elshafie, Sittana; Taj-Aldeen, Saad J

    2016-01-01

    Background Streptococcus pneumoniae is the leading cause of meningitis and sepsis. The aim of the study was to analyze the distribution, vaccine serotype coverage, and antibiotic resistance of S. pneumoniae serotypes isolated from patients with invasive diseases, after the introduction of pneumococcal 7-valent conjugated vaccine (PCV-7). Methods A total of 134 isolates were collected from blood and cerebrospinal fluid specimens at Hamad Hospital during the period from 2005 to 2009. Isolate serotyping was done using the Quellung reaction. The prevaccination period was considered before 2005. Results The most common serotypes for all age groups were 3 (12.70%), 14 (11.90%), 1 (11.90%), 19A (9.00%), 9V (5.20%), 23F (5.20%), and 19F (4.50%). Coverage rates for infant <2 years for PCV-7, the 10-valent conjugated vaccine (PCV-10), and the 13-valent conjugated vaccine (PCV-13) were 34.78%, 52.17%, and 78.26%, respectively. Coverage rates of these vaccines were 50%, 67.86%, and 75% for the 2–5 years age group; 27.12%, 40.68%, and 64.41% for the age group 6–64 years; and 25%, 33.33%, and 66.67% for the ≥65 years age group, respectively. The percentage of nonsusceptible isolates to penicillin, cefotaxime, and erythromycin were 43.86%, 16.66%, and 22.81%, respectively. Thirty-seven isolates (32.46%) were multidrug resistant (MDR) and belonged to serotypes 14, 19A, 19F, 23F, 1, 9V, 12F, 4, 6B, 3, and 15A. Compared to previous results before the introduction of PCV-7, there was a significant reduction in penicillin-nonsusceptable S. pneumoniae from 66.67% to 43.86%, and a slight insignificant reduction in erythromycin nonsusceptible strains from 27.60% to 22.8%, while there was a significant increase in cefotaxime nonsusceptible strains from 3.55% to 16.66%. Conclusion Invasive pneumococcal strains and the emergence of MDR serotypes is a global burden that must be addressed through multiple strategies, including vaccination, antibiotic stewardship, and continuous

  17. A novel mating approach for genetic algorithms.

    PubMed

    Galán, Severino F; Mengshoel, Ole J; Pinter, Rafael

    2013-01-01

    Genetic algorithms typically use crossover, which relies on mating a set of selected parents. As part of crossover, random mating is often carried out. A novel approach to parent mating is presented in this work. Our novel approach can be applied in combination with a traditional similarity-based criterion to measure distance between individuals or with a fitness-based criterion. We introduce a parameter called the mating index that allows different mating strategies to be developed within a uniform framework: an exploitative strategy called best-first, an explorative strategy called best-last, and an adaptive strategy called self-adaptive. Self-adaptive mating is defined in the context of the novel algorithm, and aims to achieve a balance between exploitation and exploration in a domain-independent manner. The present work formally defines the novel mating approach, analyzes its behavior, and conducts an extensive experimental study to quantitatively determine its benefits. In the domain of real function optimization, the experiments show that, as the degree of multimodality of the function at hand grows, increasing the mating index improves performance. In the case of the self-adaptive mating strategy, the experiments give strong results for several case studies.

  18. Antimicrobial susceptibility and plasmid replicon typing of Salmonella enterica serovar Kentucky isolates recovered from broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella Kentucky has become the predominate serotype recovered from broiler slaughter in the United States and the prevalence of antimicrobial resistance (AMR) has increased dramatically in this serotype. Relationships between AMR, genotype, and plasmid replicon types were characterized for 600 ...

  19. Determination of dengue virus serotypes in individual Aedes aegypti mosquitoes in Colombia.

    PubMed

    Romero-Vivas, C M; Leake, C J; Falconar, A K

    1998-07-01

    Adult Aedes aegypti mosquitoes were collected in Puerto Triunfo, central Colombia, where dengue is endemic, during a six month period. Viral infection within the head of each individual mosquito was identified by an immunofluorescent assay (IFA) using a flavivirus-specific monoclonal antibody. The dengue virus serotype, present in each flavivirus-positive specimen, was then determined in portions of the remaining thorax using IFAs with serotype-specific monoclonal antibodies. Among 2065 female Aedes aegypti collected and tested, twenty-four flavivirus-positive individuals were found (minimum infection rate 11.6%), three identified as dengue type-1 and twenty-one as dengue type-2 virus. This was consistent with the isolation of only these two serotypes of dengue virus from dengue fever patients within this town. No vertical transmission of dengue virus could be detected in 1552 male Aedes aegypti collected. This method is inexpensive, simple, rapid to perform and suitable for use in developing countries to identify and distinguish different serotypes of dengue virus in their vectors during eco-epidemiological investigations.

  20. Regulatory gene mutation: a driving force behind group a Streptococcus strain- and serotype-specific variation.

    PubMed

    Sarkar, Poulomee; Sumby, Paul

    2017-02-01

    Data from multiple bacterial pathogens are consistent with regulator-encoding genes having higher mutation frequencies than the genome average. Such mutations drive both strain- and type- (e.g., serotype, haplotype) specific phenotypic heterogeneity, and may challenge public health due to the potential of variants to circumvent established treatment and/or preventative regimes. Here, using the human bacterial pathogen the group A Streptococcus (GAS; S. pyogenes) as a model organism, we review the types and regulatory-, phenotypic-, and disease-specific consequences of naturally occurring regulatory gene mutations. Strain-specific regulator mutations that will be discussed include examples that transform isolates into hyper-invasive forms by enhancing expression of immunomodulatory virulence factors, and examples that promote asymptomatic carriage of the organism. The discussion of serotype-specific regulator mutations focuses on serotype M3 GAS isolates, and how the identified rewiring of regulatory networks in this serotype may be contributing to a decades old epidemiological association of M3 isolates with particularly severe invasive infections. We conclude that mutation plays an outsized role in GAS pathogenesis and has clinical relevance. Given the phenotypic variability associated with regulatory gene mutations, the rapid examination of these genes in infecting isolates may inform with respect to potential patient complications and treatment options.

  1. Analysis of Multilocus Sequence Typing for Identification of Leptospira Isolates in Brazil ▿

    PubMed Central

    Romero, E. C.; Blanco, R. M.; Galloway, R. L.

    2011-01-01

    A collection of 101 Leptospira isolates was tested by multilocus sequence typing (MLST) and by traditional serotyping. MLST divided the isolates into 4 sequence types (STs), while serotyping classified them into 6 serogroups. Two isolates failed to generate products for some genes by MLST. MLST was less discriminatory than serotyping for uncommonly occurring isolates from humans in Brazil. PMID:21880969

  2. Is Evolution of Mating Preferences Inevitable? Random Mating in the Multisex System of Tetrahymena thermophila

    PubMed Central

    Phadke, Sujal S.; Cooper, Lauren; Zufall, Rebecca A.

    2012-01-01

    Ciliate mating systems are highly diversified, providing unique opportunities to study sexual differentiation and its implications for mating dynamics. Many species of ciliates have multiple (>2) sexes. More sexes may mean more choice and an opportunity for evolution of preferential mating. We asked if the multiple sexes of the ciliate Tetrahymena thermophila mate preferentially among each other. We quantified pairing frequencies among four sexes of T. thermophila using experiments that allowed the sexes to compete as mating partners. We found that all sexes mated equally frequently among each other, that is, we found no evidence of preferential mating with respect to sex. This suggests that the “mate choice” in this ciliate is binary, between whether to form a pair or not and, in this regard, sex facilitates only self-/non-self-distinction. Thus, presence of multiple sexes does not necessarily result in the evolution of mating bias, which could decrease the maximum amount of mating that would otherwise be possible in a population. Our result of random mating verifies a key assumption in the theoretical model of sex ratio evolution in T. thermophila. Investigation into molecular differences between the sexes will be necessary to reveal the mechanistic basis of random mating among them. PMID:23056994

  3. Direct costs and benefits of multiple mating: Are high female mating rates due to ejaculate replenishment?

    PubMed

    Worthington, Amy M; Kelly, Clint D

    2016-03-01

    Females often mate more than is necessary to ensure reproductive success even when they incur significant costs from doing so. Direct benefits are hypothesized to be the driving force of high female mating rates, yet species in which females only receive an ejaculate from their mate still realize increased fitness from multiple mating. Using the Texas field cricket, Gryllus texensis, we experimentally test the hypothesis that multiple mating via monandry or polyandry increases female fitness by replenishing ejaculates, thereby allowing females to produce more offspring for a longer period of time. We found that higher rates of female mating significantly increased lifetime fecundity and oviposition independent of whether females mated with one or two males. Further, although interactions with males significantly increased rates of injury or death, females that replenished ejaculates experienced an increased rate and duration of oviposition, demonstrating that the immediate benefits of multiple mating may greatly outweigh the long-term costs that mating poses to female condition and survival. We suggest that ejaculate replenishment is a driving factor of high mating rates in females that do not receive external direct benefits from mating and that a comparative study across taxa will provide additional insight into the role that ejaculate size plays in the evolution of female mating rates.

  4. Polyandry and alternative mating tactics

    PubMed Central

    Neff, Bryan D.; Svensson, Erik I.

    2013-01-01

    Many species in the animal kingdom are characterized by alternative mating tactics (AMTs) within a sex. In males, such tactics include mate guarding versus sneaking behaviours, or territorial versus female mimicry. Although AMTs can occur in either sex, they have been most commonly described in males. This sex bias may, in part, reflect the increased opportunity for sexual selection that typically exists in males, which can result in a higher probability that AMTs evolve in that sex. Consequently, females and polyandry can play a pivotal role in governing the reproductive success associated with male AMTs and in the evolutionary dynamics of the tactics. In this review, we discuss polyandry and the evolution of AMTs. First, we define AMTs and review game theoretical and quantitative genetic approaches used to model their evolution. Second, we review several examples of AMTs, highlighting the roles that genes and environment play in phenotype expression and development of the tactics, as well as empirical approaches to differentiating among the mechanisms. Third, ecological and genetic constraints to the evolution of AMTs are discussed. Fourth, we speculate on why female AMTs are less reported on in the literature than male tactics. Fifth, we examine the effects of AMTs on breeding outcomes and female fitness, and as a source, and possibly also a consequence, of sexual conflict. We conclude by suggesting a new model for the evolution of AMTs that incorporates both environmental and genetic effects, and discuss some future avenues of research. PMID:23339236

  5. Women who kill their mates.

    PubMed

    Bourget, Dominique; Gagné, Pierre

    2012-01-01

    Spousal homicide perpetrators are much more likely to be men than women. Accordingly, little research has focused on delineating characteristics of women who have committed spousal homicide. A retrospective clinical review of coroners' files containing all cases of spousal homicide occurring in Quebec over a 20-year period was carried out. A total of 276 spousal homicides occurred between 1991 and 2010, with 42 homicides by female spouses and 234 homicides by male spouses. Differences between homicides committed by female offenders and male offenders are discussed, and findings on spousal homicide committed by women are compared with those of previous studies. Findings regarding offenses perpetrated by females in the context of mental illness, domestic violence, and homicide-suicide are explored. The finding that only 28% of the female offenders in the Quebec sample had previously been subjected to violence by their victim is in contrast to the popular belief and reports that indicate that most female-perpetrated spousal homicide occurs in self-defense or in reaction to long-term abuse. In fact, women rarely gave a warning before killing their mates. Most did not suffer from a mental illness, although one-fifth were acutely intoxicated at the time of the killing. In the vast majority of cases of women who killed their mates, there were very few indicators that might have signaled the risk and helped predict the violent lethal behavior.

  6. Clade Replacements in Dengue Virus Serotypes 1 and 3 Are Associated with Changing Serotype Prevalence†

    PubMed Central

    Zhang, Chunlin; Mammen, Mammen P.; Chinnawirotpisan, Piyawan; Klungthong, Chonticha; Rodpradit, Prinyada; Monkongdee, Patama; Nimmannitya, Suchitra; Kalayanarooj, Siripen; Holmes, Edward C.

    2005-01-01

    The evolution of dengue virus (DENV) is characterized by phylogenetic trees that have a strong temporal structure punctuated by dramatic changes in clade frequency. To determine the cause of these large-scale phylogenetic patterns, we examined the evolutionary history of DENV serotype 1 (DENV-1) and DENV-3 in Thailand, where gene sequence and epidemiological data are relatively abundant over a 30-year period. We found evidence for the turnover of viral clades in both serotypes, most notably in DENV-1, where a major clade replacement event took place in genotype I during the mid-1990s. Further, when this clade replacement event was placed in the context of changes in serotype prevalence in Thailand, a striking pattern emerged; an increase in DENV-1 clade diversity was associated with an increase in the abundance of this serotype and a concomitant decrease in DENV-4 prevalence, while clade replacement was associated with a decline in DENV-1 prevalence and a rise of DENV-4. We postulate that intraserotypic genetic diversification proceeds at times of relative serotype abundance and that replacement events can result from differential susceptibility to cross-reactive immune responses. PMID:16306584

  7. Why are dengue virus serotypes so distantly related? Enhancement and limiting serotype similarity between dengue virus strains.

    PubMed Central

    Kawaguchi, Isao; Sasaki, Akira; Boots, Michael

    2003-01-01

    Dengue virus, the causative agent of dengue fever, has four major serotypes characterized by large genetic and immunological distances. We propose that the unusually large distances between the serotypes can be explained in the light of a process of antibody-dependent enhancement (ADE) leading to increased mortality. Antibody-dependent enhancement results from a new infection with a particular serotype in an individual with acquired immunity to a different serotype. Classical dengue fever causes negligible mortality, but ADE leads to the risk of developing the significantly more dangerous dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). A mathematical model is presented that describes the epidemiological dynamics of two serotypes of a pathogen where there is the possibility of co-infection and reinfection by a different serotype, along with increased mortality as a result of enhancement. We show that if there is no or slightly increased mortality after reinfection (enhancement), serotypes with a small immunological distance can stably coexist. This suggests that a cloud of serotypes with minor serological differences will constitute the viral population. By contrast, if enhancement is sufficiently great, a substantial immunological distance is necessary for two serotypes to stably coexist in the population. Therefore, high mortality owing to enhancement leads to an evolutionarily stable viral community comprising a set of distantly separated serotypes. PMID:14613610

  8. Systematic Evaluation of Serotypes Causing Invasive Pneumococcal Disease among Children Under Five: The Pneumococcal Global Serotype Project

    PubMed Central

    Johnson, Hope L.; Deloria-Knoll, Maria; Levine, Orin S.; Stoszek, Sonia K.; Freimanis Hance, Laura; Reithinger, Richard; Muenz, Larry R.; O'Brien, Katherine L.

    2010-01-01

    Background Approximately 800,000 children die each year due to pneumococcal disease and >90% of these deaths occur in developing countries where few children have access to life-saving serotype-based vaccines. Understanding the serotype epidemiology of invasive pneumococcal disease (IPD) among children is necessary for vaccine development and introduction policies. The aim of this study was to systematically estimate the global and regional distributions of serotypes causing IPD in children <5 years of age. Methods and Findings We systematically reviewed studies with IPD serotype data among children <5 years of age from the published literature and unpublished data provided by researchers. Studies conducted prior to pneumococcal conjugate vaccine (PCV) introduction, from 1980 to 2007, with ≥12 months of surveillance, and reporting ≥20 serotyped isolates were included. Serotype-specific proportions were pooled in a random effects meta-analysis and combined with PD incidence and mortality estimates to infer global and regional serotype-specific PD burden. Of 1,292, studies reviewed, 169 were included comprising 60,090 isolates from 70 countries. Globally and regionally, six to 11 serotypes accounted for ≥70% of IPD. Seven serotypes (1, 5, 6A, 6B, 14, 19F, 23F) were the most common globally; and based on year 2000 incidence and mortality estimates these seven serotypes accounted for >300,000 deaths in Africa and 200,000 deaths in Asia. Serotypes included in both the 10- and 13-valent PCVs accounted for 10 million cases and 600,000 deaths worldwide. Conclusions A limited number of serotypes cause most IPD worldwide. The serotypes included in existing PCV formulations account for 49%–88% of deaths in Africa and Asia where PD morbidity and mortality are the highest, but few children have access to these life-saving vaccines. Please see later in the article for the Editors' Summary PMID:20957191

  9. Flexible coiled spline securely joins mating cylinders

    NASA Technical Reports Server (NTRS)

    Coppernol, R. W.

    1966-01-01

    Mating cylindrical members are joined by spline to form an integral structure. The spline is made of tightly coiled, high tensile-strength steel spiral wire that fits a groove between the mating members. It provides a continuous bearing surface for axial thrust between the members.

  10. Machinist's Mate J 1 and C: Aviation.

    ERIC Educational Resources Information Center

    Naval Training Publications Center, Memphis, TN.

    The rate training manual is one of a series of training manuals prepared for enlisted personnel of the Navy and Naval Reserve studying for advancement from the Aviation Machinist's Mate ADJ2 rating to ADJ1 to ADJC. Aviation Machinist's Mates J maintain aircraft jet engines and their related systems. Chpater 1 discusses the enlisted rating…

  11. Mate Choice: Charting Desire's Tangled Bank.

    PubMed

    Rosenthal, Gil G

    2016-04-04

    Choosing a mate requires a way to turn sexual arousal into sexual action. A recent paper identifies a hormone receptor that acts as a molecular gatekeeper in reproductive decisions. Focusing on mate-choice mechanisms may clarify longstanding evolutionary puzzles in sexual selection and speciation.

  12. Electrician's Mate 3 & 2: Rate Training Manual.

    ERIC Educational Resources Information Center

    Naval Education and Training Command, Pensacola, FL.

    The training manual provides information related to the tasks assigned to the Electrician's Mate Third and Second Class who operate and maintain power and lighting systems and associated equipment. Individual chapters deal with: career challenges for the Electrician's Mate, safety precautions, test equipment, electrical installations, A-C power…

  13. Disrupting mating behavior of Diaphorina citri (Liviidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Severe economic damage from citrus greening disease, caused by ‘Candidatus Liberibacter asiaticus’ bacteria, has stimulated development of methods to reduce mating and reproduction in populations of its insect vector, Diaphorina citri (Hemiptera: Liviidae). Male D. citri find mating partners by walk...

  14. 46 CFR 12.711 - Apprentice mate.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Apprentice mate. 12.711 Section 12.711 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN REQUIREMENTS FOR RATING ENDORSEMENTS Entry-Level National Ratings and Miscellaneous Ratings § 12.711 Apprentice mate. (a) A...

  15. Mate choice for optimal (k)inbreeding.

    PubMed

    Puurtinen, Mikael

    2011-05-01

    Mating between related individuals results in inbreeding depression, and this has been thought to select against incestuous matings. However, theory predicts that inbreeding can also be adaptive if it increases the representation of genes identical by descent in future generations. Here, I recapitulate the theory of inclusive fitness benefits of incest, and extend the existing theory by deriving the stable level of inbreeding in populations practicing mate choice for optimal inbreeding. The parsimonious assumptions of the model are that selection maximizes inclusive fitness, and that inbreeding depression is a linear function of homozygosity of offspring. The stable level of inbreeding that maximizes inclusive fitness, and is expected to evolve by natural selection, is shown to be less than previous theory suggests. For wide range of realistic inbreeding depression strengths, mating with intermediately related individuals maximizes inclusive fitness. The predicted preference for intermediately related individuals as reproductive partners is in qualitative agreement with empirical evidence from mate choice experiments and reproductive patterns in nature.

  16. Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China.

    PubMed

    Li, Liping; Wang, Rui; Liang, Wanwen; Gan, Xi; Huang, Ting; Huang, Yan; Li, Jian; Shi, Yunliang; Chen, Ming; Luo, Honglin

    2013-12-27

    Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae (GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the first time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in five provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding 36.9% (62/168), 37.5% (63/168) and 19.6% (33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia (95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010, but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during 2007-2011, III only occurred in 2012. 14 different PFGE types, including 4 new types (N, O, P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9% (141/168) of the total GBS strains. Ia corresponded to 11 PFGE types (A-H, N-P), in which type D predominated (51%). Ib represented 3 genotypes (I, J and Q) and III harbored only 2 genotypes (N and F). Type N and F synchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years. Although Ia still predominated, new rare serotype III already occurred in China.

  17. Reappraisal of the taxonomy of Streptococcus suis serotypes 20, 22 and 26: Streptococcus parasuis sp. nov.

    PubMed

    Nomoto, R; Maruyama, F; Ishida, S; Tohya, M; Sekizaki, T; Osawa, Ro

    2015-02-01

    In order to clarify the taxonomic position of serotypes 20, 22 and 26 of Streptococcus suis, biochemical and molecular genetic studies were performed on isolates (SUT-7, SUT-286(T), SUT-319, SUT-328 and SUT-380) reacted with specific antisera of serotypes 20, 22 or 26 from the saliva of healthy pigs as well as reference strains of serotypes 20, 22 and 26. Comparative recN gene sequencing showed high genetic relatedness among our isolates, but marked differences from the type strain S. suis NCTC 10234(T), i.e. 74.8-75.7 % sequence similarity. The genomic relatedness between the isolates and other strains of species of the genus Streptococcus, including S. suis, was calculated using the average nucleotide identity values of whole genome sequences, which indicated that serotypes 20, 22 and 26 should be removed taxonomically from S. suis and treated as a novel genomic species. Comparative sequence analysis revealed 99.0-100 % sequence similarities for the 16S rRNA genes between the reference strains of serotypes 20, 22 and 26, and our isolates. Isolate STU-286(T) had relatively high 16S rRNA gene sequence similarity with S. suis NCTC 10234(T) (98.8 %). SUT-286(T) could be distinguished from S. suis and other closely related species of the genus Streptococcus using biochemical tests. Due to its phylogenetic and phenotypic similarities to S. suis we propose naming the novel species Streptococcus parasuis sp. nov., with SUT-286(T) ( = JCM 30273(T) = DSM 29126(T)) as the type strain.

  18. [Group B streptococci: serotyping data and susceptibility to antibiotics (author's transl)].

    PubMed

    Rousset, A; Lévy, A; Minck, R

    1977-10-01

    A study of the prevalence of group B streptococci in women (covering 6,000 samples) shows the vaginal presence to be comprised between 6.34 and 16.8%. The highest rate is found in a Centre for venereal diseases. The use of selective media results in a 50 to 75% increase in the number of germ-carries. The distribution found after serotyping of 1,469 strains has been studied. Over half of the strains isolated from the vagina and from infants belong to serotype II and III, one third of the strains causing serious infections are of type III; however, there is a wide dispersion of the serotypes found in neonatal infections. The test for pigmentation on Columbia medium offers an excellent approach for the diagnosis of group B streptococci. MIC testing of 7 antibiotics for 782 strains of various serotypes demonstrates high susceptibility to the beta-lactam antibiotics and makes it possible to detect rare strains with features of polyresistance to chloramphenicol and some macrolide antibiotics.

  19. Adeno-associated viral vector serotype 5 poorly transduces liver in rat models.

    PubMed

    Montenegro-Miranda, Paula S; Pañeda, Astrid; ten Bloemendaal, Lysbeth; Duijst, Suzanne; de Waart, Dirk R; Gonzalez- Aseguinolaza, Gloria; Aseguinolaza, Gloria Gonzalez; Bosma, Piter J

    2013-01-01

    Preclinical studies in mice and non-human primates showed that AAV serotype 5 provides efficient liver transduction and as such seems a promising vector for liver directed gene therapy. An advantage of AAV5 compared to serotype 8 already shown to provide efficient correction in a phase 1 trial in patients suffering from hemophilia B, is its lower seroprevalence in the general population. Our goal is liver directed gene therapy for Crigler-Najjar syndrome type I, inherited severe unconjugated hyperbilirubinemia caused by UGT1A1 deficiency. In a relevant animal model, the Gunn rat, we compared the efficacy of AAV 5 and 8 to that of AAV1 previously shown to be effective. Ferrying a construct driving hepatocyte specific expression of UGT1A1, both AAV8 and AAV1 provided an efficient correction of hyperbilirubinemia. In contrast to these two and to other animal models AAV5 failed to provide any correction. To clarify whether this unexpected finding was due to the rat model used or due to a problem with AAV5, the efficacy of this serotype was compared in a mouse and two additional rat strains. Administration of an AAV5 vector expressing luciferase under the control of a liver specific promoter confirmed that this serotype poorly performed in rat liver, rendering it not suitable for proof of concept studies in this species.

  20. Contribution of Flagellin Pattern Recognition to Intestinal Inflammation during Salmonella enterica Serotype Typhimurium Infection▿

    PubMed Central

    Winter, Sebastian E.; Thiennimitr, Parameth; Nuccio, Sean-Paul; Haneda, Takeshi; Winter, Maria G.; Wilson, R. Paul; Russell, Joseph M.; Henry, Thomas; Tran, Quynh T.; Lawhon, Sara D.; Gomez, Gabriel; Bevins, Charles L.; Rüssmann, Holger; Monack, Denise M.; Adams, L. Garry; Bäumler, Andreas J.

    2009-01-01

    Salmonella enterica serotype Typhimurium causes acute inflammatory diarrhea in humans. Flagella contribute to intestinal inflammation, but the mechanism remains unclear since most mutations abrogating pattern recognition of flagellin also prevent motility and reduce bacterial invasion. To determine the contribution of flagellin pattern recognition to the generation of innate immune responses, we compared in two animal models a nonmotile, but flagellin-expressing and -secreting serotype Typhimurium strain (flgK mutant) to a nonmotile, non-flagellin-expressing strain (flgK fliC fljB mutant). In vitro, caspase-1 can be activated by cytosolic delivery of flagellin, resulting in release of the interferon gamma inducing factor interleukin-18 (IL-18). Experiments with streptomycin-pretreated caspase-1-deficient mice suggested that induction of gamma interferon expression in the murine cecum early (12 h) after serotype Typhimurium infection was caspase-1 dependent but independent of flagellin pattern recognition. In addition, mRNA levels of the CXC chemokines macrophage inflammatory protein 2 and keratinocyte-derived chemokine were markedly increased early after serotype Typhimurium infection of streptomycin-pretreated wild-type mice regardless of flagellin expression. In contrast, in bovine ligated ileal loops, flagellin pattern recognition contributed to increased mRNA levels of macrophage inflammatory protein 3α and more fluid accumulation at 2 h after infection. Collectively, our data suggest that pattern recognition of flagellin contributes to early innate host responses in the bovine ileal mucosa but not in the murine cecal mucosa. PMID:19237529

  1. Mating-defective ste mutations are suppressed by cell division cycle start mutations in Saccharomyces cerevisiae.

    PubMed Central

    Shuster, J R

    1982-01-01

    Temperature-sensitive mutants which arrest in the G1 phase of the cell cycle have been described for the yeast Saccharomyces cerevisiae. One class of these mutants (carrying cdc28, cdc36, cdc37, or cdc39) forms a shmoo morphology at restrictive temperature, characteristic of mating pheromone-arrested wild-type cells. Therefore, one hypothesis to explain the control of cell division by mating factors states that mating pheromones arrest wild-type cells by inactivating one or more of these CDC gene products. A class of mutants (carrying ste4, ste5, ste7, ste11, or ste12) which is insensitive to mating pheromone and sterile has also been described. One possible function of the STE gene products is the inactivation of the CDC gene products in the presence of a mating pheromone. A model incorporating these two hypotheses predicts that such STE gene products will not be required for mating in strains carrying an appropriate cdc lesion. This prediction was tested by assaying the mating abilities of double mutants for all of the pairwise combinations of cdc and ste mutations. Lesions in either cdc36 or cdc39 suppressed the mating defect due to ste4 and ste5. Allele specificity was observed in the suppression of both ste4 and ste5. The results indicate that the CDC36, CDC39, STE4, and STE5 gene products interact functionally or physically or both in the regulation of cell division mediated by the presence or absence of mating pheromones. The cdc36 and cdc39 mutations did not suppress ste7, ste11, or ste12. Lesions in cdc28 or cdc37 did not suppress any of the ste mutations. Other models of CDC and STE gene action which predicted that some of the cdc and ste mutations would be alleles of the same locus were tested. None of the cdc mutations was allelic to the ste mutations and, therefore, these models were eliminated. PMID:6757719

  2. SKYLAB 2 - SATURN IB MATING

    NASA Technical Reports Server (NTRS)

    1972-01-01

    KENNEDY SPACE CENTER, FL - The Saturn IB second (S-IVB) stage for the Skylab 2 launch vehicle was mated with the first (S-IB) stage in High Bay 1 of the VAB. This view shows the stage as it was moved by an overhead crane from the VAB transfer aisle into the bay. On the Skylab 2 mission, and Apollo spacecraft will carry Astronauts Charles Conrad, Dr. Joseph Kerwin and Paul Weitz into Earth orbit to rendezvous and dock with Skylab 1, the first US manned orbiting space station. They will enter the space station to live and conduct experiments during a 28-day mission, then return to Earth in the Apollo.

  3. Methylxanthines and phenolics content extracted during the consumption of mate (Ilex paraguariensis St. Hil) beverages.

    PubMed

    Meinhart, Adriana Dillenburg; Bizzotto, Carolina Schaper; Ballus, Cristiano Augusto; Poloni Rybka, Ana Cecília; Sobrinho, Merenice Roberto; Cerro-Quintana, Romina Sofia; Teixeira-Filho, José; Godoy, Helena Teixeira

    2010-02-24

    "Chimarrao" and "terere" are popular beverages consumed in South America prepared using mate (Ilex paraguariensis St. Hil.). "Chimarrao" consists of a partial infusion where hot water is added, while "terere" is a total infusion, with addition of cold water. This study was designed to simulate preparation of these beverages for consumption, in order to estimate the total amount of xanthines and phenolic compounds in aqueous extracts that would be ingested by the consumer. Different commercial types of mate were employed for "chimarrao" preparation (native, smooth, traditional, and course-ground), and these were compared to "terere". In "chimarrao", beverages from coarse-ground mate showed the highest levels of xanthines. However, "terere" presented quantities 2.5 times higher than the beverage of the coarse-ground mate. Considering the total phenolics in "chimarrao", there was no difference between the types of herbs, but in "terere", the extraction of almost all of the phenolics was observed.

  4. Streptococcus agalactiae Serotype IV in Humans and Cattle, Northern Europe1

    PubMed Central

    Lyhs, Ulrike; Kulkas, Laura; Katholm, Jørgen; Waller, Karin Persson; Saha, Kerttu; Tomusk, Richard J.

    2016-01-01

    Streptococcus agalactiae is an emerging pathogen of nonpregnant human adults worldwide and a reemerging pathogen of dairy cattle in parts of Europe. To learn more about interspecies transmission of this bacterium, we compared contemporaneously collected isolates from humans and cattle in Finland and Sweden. Multilocus sequence typing identified 5 sequence types (STs) (ST1, 8, 12, 23, and 196) shared across the 2 host species, suggesting possible interspecies transmission. More than 54% of the isolates belonged to those STs. Molecular serotyping and pilus island typing of those isolates did not differentiate between populations isolated from different host species. Isolates from humans and cattle differed in lactose fermentation, which is encoded on the accessory genome and represents an adaptation to the bovine mammary gland. Serotype IV-ST196 isolates were obtained from multiple dairy herds in both countries. Cattle may constitute a previously unknown reservoir of this strain. PMID:27869599

  5. The distribution of serotype-specific plasmids among different subgroups of strains of Salmonella enterica serotype Enteritidis: characterization of molecular variants by restriction enzyme fragmentation patterns.

    PubMed Central

    Rankin, S. C.; Benson, C. E.; Platt, D. J.

    1995-01-01

    Four hundred and thirty-four isolates of Salmonella enterica serotype Enteritidis were studied. They were grouped into five subsets defined by either the collection criteria or the parameter which formed the basis for subsequent analysis. Seventy-seven per cent harboured the serotype-specific plasmid (SSP). In 55% of the isolates this was the sole plasmid. Molecular variation in the SSP was detected in 17 (5%) of the isolates on the basis of restriction enzyme fragmentation pattern (REFP) analysis using Pst I and Sma I. The SSP variants were further characterized using additional restriction enzymes chosen to optimize the information content and analysed using a coefficient of similarity. A variant SSP designated pOG690 showed greater resemblance to the SSP of Salmonella enterica serotype Typhimurium than Enteritidis; 89% and 68% respectively for Pst I and 79% and 55% respectively for Sma I. In respect of the Pst I data pOG690 shared at least 55 kb of DNA with the Typhimurium SSP and 37 kb with the SSP of Enteritidis. This variant was associated with poultry (duck, goose, chicken) and all isolates belonged to phage type 9b. Other variants were associated with phage types 4, 6, 6a, 9a, 11, 15 and 24. The epidemiological implications of these results are discussed. Images Fig. 1 PMID:7867741

  6. Variation in mate-recognition pheromones of the fungal genus Microbotryum

    PubMed Central

    Xu, L; Petit, E; Hood, M E

    2016-01-01

    Mate recognition is an essential life-cycle stage that exhibits strong conservation in function, whereas diversification of mating signals can contribute directly to the integrity of species boundaries through assortative mating. Fungi are simple models, where compatibility is based on the recognition of pheromone peptides by corresponding receptor proteins, but clear patterns of diversification have not emerged from the species examined, which are few compared with mate signaling studies in plant and animal systems. In this study, candidate loci from Microbotryum species were used to characterize putative pheromones that were synthesized and found to be functional across multiple species in triggering a mating response in vitro. There is no significant correlation between the strength of a species' response and its genetic distance from the pheromone sequence source genome. Instead, evidence suggests that species may be strong or weak responders, influenced by environmental conditions or developmental differences. Gene sequence comparisons reveals very strong purifying selection on the a1 pheromone peptide and corresponding receptor, but significantly less purifying selection on the a2 pheromone peptide that corresponds with more variation across species in the receptor. This represents an exceptional case of a reciprocally interacting mate-recognition system in which the two mating types are under different levels of purifying selection. PMID:26306729

  7. Mating system of Brassica napus and its relationship with morphological and ecological parameters in northwestern Spain.

    PubMed

    Soengas, Pilar; Velasco, Pablo; Vilar, Marta; Cartea, Maria Elena

    2013-01-01

    Mating systems play a central role in determining population genetic structure and the methods to be used to develop new cultivars and preserve the variability of a crop. A Brassica napus crop called nabicol is grown in northwestern Spain. Knowledge on its mating system is needed in order to manage the germplasm correctly and design breeding strategies. The aims of this work were to study the mating system of nabicol under field conditions and the relationship of different traits with the mating system. We analyzed 2 populations with microsatellites using a multilocus approach, finding that both had a mixed mating system with an outcrossing rate of 30%. This system would allow application of breeding methods for both autogamous and allogamous species in order to improve nabicol populations. Nabicol populations should be multiplied in isolation conditions in the same way as allogamous species in order to avoid contamination and preserve genetic integrity. The relationship of outcrossing rate, phenological, ecological, and morphological traits was studied, but the model explained only a small percentage of the variability. None of the traits studied could be used as indirect selection criteria for a type of mating system under the conditions of northwestern Spain. This is the first work that studies in depth the possible causes of the mixed mating system of B. napus, finding that, surprisingly, it is not related to the most obvious factors.

  8. The mating behavior of Iguana iguana

    USGS Publications Warehouse

    Rodda, G.H.

    1992-01-01

    Over a 19 month period I observed the social behaviors of individually recognized green iguanas, Iguana iguana, at three sites in the llanos of Venezuela. The behavior of iguanas outside the mating season differed from that seen during the mating season in three major ways: (1) during normal waking hours outside the breeding season, adult iguanas spent the majority of time immobile, apparently resting; (2) their interactions involved fewer high intensity displays; and (3) their day to day movements were often nomadic. During the mating season, one site was watched continuously during daylight hours (iguanas sleep throughout the night), allowing a complete count of all copulation attempts (N = 250) and territorial interactions. At all sites, dominant males controlled access to small mating territories. Within the territories there did not appear to be any resources needed by females or their offspring. Thus, females could choose mates directly on the basis of male phenotype. Females aggregated in the mating territories of the largest males and mated preferentially with them. Territorial males copulated only once per day, although on several occasions more than one resident female was receptive on the same day. A few small nonterritorial males exhibited pseudofemale behavior (i.e., they abstained from sexual competition), but most nonterritorial males stayed on the periphery of mating territories and attempted to force copulations on unguarded females (peripheral male behavior). Uncooperative females were mounted by as many as three males simultaneously. Females resisted 95% of the 200 observed mating attempts by peripheral males, but only 56% of the attempts by territorial males (N = 43). The selectivity of the females probably increased the genetic representation of the territorial males in the next generation. During the mating season females maintained a dominance hierarchy among themselves. Low ranked females tended to be excluded from preferred

  9. A comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice

    PubMed Central

    Sivula, Christine P; Bogomolnaya, Lydia M; Andrews-Polymenis, Helene L

    2008-01-01

    Background Salmonellosis is one of the most important bacterial food borne illnesses worldwide. A major source of infection for humans is consumption of chicken or egg products that have been contaminated with Salmonella enterica serotype Typhimurium, however our knowledge regarding colonization and persistence factors in the chicken is small. Results We compared intestinal and systemic colonization of 1-week-old White Leghorn chicks and Salmonella-resistant CBA/J mice during infection with Salmonella enterica serotype Typhimurium ATCC14028, one of the most commonly studied isolates. We also studied the distribution of wild type serotype Typhimurium ATCC14028 and an isogenic invA mutant during competitive infection in the cecum of 1-week-old White Leghorn chicks and 8-week-old CBA/J mice. We found that although the systemic levels of serotype Typhimurium in both infected animal models are low, infected mice have significant splenomegaly beginning at 15 days post infection. In the intestinal tract itself, the cecal contents are the major site for recovery of serotype Typhimurium in the cecum of 1-week-old chicks and Salmonella-resistant mice. Additionally we show that only a small minority of Salmonellae are intracellular in the cecal epithelium of both infected animal models, and while SPI-1 is important for successful infection in the murine model, it is important for association with the cecal epithelium of 1-week-old chicks. Finally, we show that in chicks infected with serotype Typhimurium at 1 week of age, the level of fecal shedding of this organism does not reflect the level of cecal colonization as it does in murine models. Conclusion In our study, we highlight important differences in systemic and intestinal colonization levels between chick and murine serotype Typhimurium infections, and provide evidence that suggests that the role of SPI-1 may not be the same during colonization of both animal models. PMID:18922185

  10. Slaughterhouse pigs are a major reservoir of Streptococcus suis serotype 2 capable of causing human infection in southern Vietnam.

    PubMed

    Ngo, Thi Hoa; Tran, Thi Bich Chieu; Tran, Thi Thu Nga; Nguyen, Van Dung; Campbell, James; Pham, Hong Anh; Huynh, Huu Tho; Nguyen, Van Vinh Chau; Bryant, Juliet E; Tran, Tinh Hien; Farrar, Jeremy; Schultsz, Constance

    2011-03-28

    Streptococcus suis is a pathogen of major economic significance to the swine industry and is increasingly recognized as an emerging zoonotic agent in Asia. In Vietnam, S. suis is the leading cause of bacterial meningitis in adult humans. Zoonotic transmission is most frequently associated with serotype 2 strains and occupational exposure to pigs or consumption of infected pork. To gain insight into the role of pigs for human consumption as a reservoir for zoonotic infection in southern Vietnam, we determined the prevalence and diversity of S. suis carriage in healthy slaughterhouse pigs. Nasopharyngeal tonsils were sampled from pigs at slaughterhouses serving six provinces in southern Vietnam and Ho Chi Minh City area from September 2006 to November 2007. Samples were screened by bacterial culture. Isolates of S. suis were serotyped and characterized by multi locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE). Antibiotic susceptibility profiles and associated genetic resistance determinants, and the presence of putative virulence factors were determined. 41% (222/542) of pigs carried S. suis of one or multiple serotypes. 8% (45/542) carried S. suis serotype 2 which was the most common serotype found (45/317 strains, 14%). 80% of serotype 2 strains belonged to the MLST clonal complex 1,which was previously associated with meningitis cases in Vietnam and outbreaks of severe disease in China in 1998 and 2005. These strains clustered with representative strains isolated from patients with meningitis in PFGE analysis, and showed similar antimicrobial resistance and virulence factor profiles. Slaughterhouse pigs are a major reservoir of S. suis serotype 2 capable of causing human infection in southern Vietnam. Strict hygiene at processing facilities, and health education programs addressing food safety and proper handling of pork should be encouraged.

  11. Slaughterhouse Pigs Are a Major Reservoir of Streptococcus suis Serotype 2 Capable of Causing Human Infection in Southern Vietnam

    PubMed Central

    Hoa, Ngo Thi; Chieu, Tran Thi Bich; Nga, Tran Thi Thu; Dung, Nguyen Van; Campbell, James; Anh, Pham Hong; Huu Tho, Huynh; Van Vinh Chau, Nguyen; Bryant, Juliet E.; Hien, Tran Tinh; Farrar, Jeremy; Schultsz, Constance

    2011-01-01

    Streptococcus suis is a pathogen of major economic significance to the swine industry and is increasingly recognized as an emerging zoonotic agent in Asia. In Vietnam, S. suis is the leading cause of bacterial meningitis in adult humans. Zoonotic transmission is most frequently associated with serotype 2 strains and occupational exposure to pigs or consumption of infected pork. To gain insight into the role of pigs for human consumption as a reservoir for zoonotic infection in southern Vietnam, we determined the prevalence and diversity of S. suis carriage in healthy slaughterhouse pigs. Nasopharyngeal tonsils were sampled from pigs at slaughterhouses serving six provinces in southern Vietnam and Ho Chi Minh City area from September 2006 to November 2007. Samples were screened by bacterial culture. Isolates of S. suis were serotyped and characterized by multi locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE). Antibiotic susceptibility profiles and associated genetic resistance determinants, and the presence of putative virulence factors were determined. 41% (222/542) of pigs carried S. suis of one or multiple serotypes. 8% (45/542) carried S. suis serotype 2 which was the most common serotype found (45/317 strains, 14%). 80% of serotype 2 strains belonged to the MLST clonal complex 1,which was previously associated with meningitis cases in Vietnam and outbreaks of severe disease in China in 1998 and 2005. These strains clustered with representative strains isolated from patients with meningitis in PFGE analysis, and showed similar antimicrobial resistance and virulence factor profiles. Slaughterhouse pigs are a major reservoir of S. suis serotype 2 capable of causing human infection in southern Vietnam. Strict hygiene at processing facilities, and health education programs addressing food safety and proper handling of pork should be encouraged. PMID:21464930

  12. Streptococcus agalactiae isolates of serotypes Ia, III and V from human and cow are able to infect tilapia.

    PubMed

    Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping

    2015-10-22

    Recent studies have shown that group B streptococcus (GBS) may be infectious across hosts. The purpose of this study is to investigate the pathogenicity of clinical GBS isolates with serotypes Ia, III and V from human and cow to tilapia and the evolutionary relationship among these GBS strains of different sources. A total of 27 clinical GBS isolates from human (n=10), cow (n=2) and tilapia (n=15) were analyzed using serotyping, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Among them, 15 isolates were tested for their pathogenicity to tilapia. The results showed that five human GBS strains (2 serotype III, 2 serotype Ia and 1 serotype V) infected tilapia with mortality rate ranging from 56.67% to 100%, while the other five human GBS strains tested were unable to infect tilapia. In addition, two cow GBS strains C001 and C003 of serotype III infected tilapia. However, they had significantly lower pathogenicity than the five human strains. Furthermore, human GBS strains H005 and H008, which had very strong ability to infect tilapia, had the same PFGE pattern. MLST analysis showed that the five human and the two cow GBS strains that were able to infect tilapia belonged to clonal complexes CC19, CC23 and CC103. The study for the first time confirmed that human or cow GBS clonal complexes CC19, CC23 and CC103 containing strains with serotypes Ia, III and V could infect tilapia and induce clinical signs under experimental conditions.

  13. Genetic diversity of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates and the first identification of serotype 20B in China.

    PubMed

    Guo, Q; Zhuo, C; Xu, Y; Huang, W; Wang, C; Zhang, S; Huang, J; Hu, F; Zhu, D; Yang, F; Wang, M

    2014-03-01

    The purpose of this study was to investigate the genetic characteristics of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates in China. A total of 377 S. pneumoniae clinical isolates, including 307 pediatric strains and 70 adult strains, were collected from eight centers in China. The minimal inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by agar dilution. Multilocus sequence typing (MLST), serotyping, and quinolone resistance-determining region (QRDR) variations were conducted in levofloxacin-nonsusceptible isolates by polymerase chain reaction (PCR)-based methods. Seven levofloxacin-nonsusceptible isolates were found, with an overall resistance rate of 1.9 % (7/377) and 8.6 % (6/70) in adults. Sequence analyses of parC, gyrA, and parE QRDRs in levofloxacin-resistant isolates demonstrated mutations in dual target sites at the hot spots. These seven strains represented multiple clones: two strains were serotype 19F (Taiwan(19F)-14) and MLST clonal complex (CC) 271/320, two were typed as 23F (Spain(23F)-1) and CC81, two were determined as serotype 20B and a new sequence type of ST6935, and one non-serotypeable pediatric strain belonged to a new sequence type of ST6946. Two serotype 19F strains possessed a variety of characteristic alterations of viridans group streptococci in gyrA (Ser114Gly) or parC (Ser52Gly, Asn91Asp). Fluoroquinolone-nonsusceptible S. pneumoniae isolates showed a substantial degree of genetic diversity and belonged to pre-existing epidemic clones together with native clones. S. pneumoniae strains with serotype 20B was recovered for the first time to be associated with levofloxacin resistance in China.

  14. Gasket Assembly for Sealing Mating Surfaces

    NASA Technical Reports Server (NTRS)

    Bryant, Melvin A., III (Inventor)

    2003-01-01

    A pair of substantially opposed mating surfaces are joined to each other and sealed in place by means of an electrically-conductive member which is placed in proximity to the mating surfaces. The electrically-conductive member has at least one element secured thereto which is positioned to contact the mating surfaces, and which softens when the electrically-conductive member is heated by passing an electric current therethrough. The softened element conforms to the mating surfaces, and upon cooling of the softened element the mating surfaces are joined together in an effective seal. Of particular significance is an embodiment of the electrically-conductive member which is a gasket having an electrically-conductive gasket base and a pair of the elements secured to opposite sides of the gasket base. This embodiment is positioned between the opposed mating surfaces to be joined to each other. Also significant is an embodiment of the electrically-conductive member which is an electrically-conductive sleeve having an element secured to its inner surface. This embodiment surrounds cylindrical members the bases of which are the substantially opposed mating surfaces to be joined, and the element on the inner surface of the sleeve contacts the outer surfaces of the cylindrical members.

  15. Dual Infection with Bluetongue Virus Serotypes and First-Time Isolation of Serotype 5 in India.

    PubMed

    Hemadri, D; Maan, S; Chanda, M M; Rao, P P; Putty, K; Krishnajyothi, Y; Reddy, G H; Kumar, V; Batra, K; Reddy, Y V; Maan, N S; Reddy, Y N; Singh, K P; Shivachandra, S B; Hegde, N R; Rahman, H; Mertens, P P C

    2016-12-21

    Bluetongue is endemic in India and has been reported from most Indian states. Of late, the clinical disease is most frequently seen in the states of Andhra Pradesh, Telangana (erstwhile Andhra Pradesh state), Tamil Nadu and Karnataka. Our analysis of diagnostic samples from bluetongue outbreaks during 2010-2011 from the state of Karnataka identified bluetongue virus (BTV) serotype 5 (BTV-5) for the first time in India. One of the diagnostic samples (CH1) and subsequent virus isolate (IND2010/02) contained both BTV-2 and BTV-5. Segment 2 (seg-2) sequence data (400 bp: nucleotides 2538-2921) for IND2010/02-BTV5, showed 94.3% nucleotide identity to BTV-5 from South Africa (Accession no. AJ585126), confirming the virus serotype and also indicating that Seg-2 was derived from a Western topotype, which is in contrast to serotype 2, that belongs to an Eastern topotype. BTV-5 has been recently reported from Africa, China, French islands and the Americas. Although the exact source of the Indian BTV-5 isolate is still to be confirmed, recent identification of additional exotic serotypes in India is of real concern and might add to the severity of the disease seen in these outbreaks.

  16. Female mate fidelity in a Lek mating system and its implications for the evolution of cooperative lekking behavior.

    PubMed

    DuVal, E H

    2013-02-01

    The extent and importance of female mate fidelity in polygynous mating systems are poorly known. Fidelity may contribute to high variance in male reproductive success when it favors attractive mates or may stabilize social interactions if females are faithful to mating sites rather than males. Using 12 years of data on genetic mate choice in the cooperatively lekking lance-tailed manakin (Chiroxiphia lanceolata), I investigated the frequency of fidelity within and between years, whether females were faithful to individual males or to mating sites across years, and whether fidelity favored attractive males. Mate fidelity occurred in 41.7% of 120 between-year comparisons and was observed for 41.1% of 73 individual females that had the opportunity to mate faithfully. Females were not more likely to mate at prior mating sites when previous mates were replaced. Faithful females mated with the same male in up to four consecutive years but were not disproportionately faithful to attractive partners. Mating history influences current mate choice, and fidelity in this lekking system apparently represents active mate choice by females but little is not cited in the text. Please provide a citation or mark this reference for deletion.consensus in mate choices among faithful females. This study underscores the prevalence of mate fidelity in polygynous mating systems and emphasizes the need to consider the larger context of lifetime reproductive behavior when interpreting patterns of female choice.

  17. Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates.

    PubMed

    Lass-Hennemann, Johanna; Deuter, Christian E; Kuehl, Linn K; Schulz, André; Blumenthal, Terry D; Schachinger, Hartmut

    2010-07-22

    Although humans usually prefer mates that resemble themselves, mating preferences can vary with context. Stress has been shown to alter mating preferences in animals, but the effects of stress on human mating preferences are unknown. Here, we investigated whether stress alters men's preference for self-resembling mates. Participants first underwent a cold-pressor test (stress induction) or a control procedure. Then, participants viewed either neutral pictures or pictures of erotic female nudes whose facial characteristics were computer-modified to resemble either the participant or another participant, or were not modified, while startle eyeblink responses were elicited by noise probes. Erotic pictures were rated as being pleasant, and reduced startle magnitude compared with neutral pictures. In the control group, startle magnitude was smaller during foreground presentation of photographs of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to self-resembling mates. In the stress group, startle magnitude was larger during foreground presentation of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to dissimilar mates. Our findings show that stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates.

  18. Effects of stress on human mating preferences: stressed individuals prefer dissimilar mates

    PubMed Central

    Lass-Hennemann, Johanna; Deuter, Christian E.; Kuehl, Linn K.; Schulz, André; Blumenthal, Terry D.; Schachinger, Hartmut

    2010-01-01

    Although humans usually prefer mates that resemble themselves, mating preferences can vary with context. Stress has been shown to alter mating preferences in animals, but the effects of stress on human mating preferences are unknown. Here, we investigated whether stress alters men's preference for self-resembling mates. Participants first underwent a cold-pressor test (stress induction) or a control procedure. Then, participants viewed either neutral pictures or pictures of erotic female nudes whose facial characteristics were computer-modified to resemble either the participant or another participant, or were not modified, while startle eyeblink responses were elicited by noise probes. Erotic pictures were rated as being pleasant, and reduced startle magnitude compared with neutral pictures. In the control group, startle magnitude was smaller during foreground presentation of photographs of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to self-resembling mates. In the stress group, startle magnitude was larger during foreground presentation of self-resembling female nudes compared with other-resembling female nudes and non-manipulated female nudes, indicating a higher approach motivation to dissimilar mates. Our findings show that stress affects human mating preferences: unstressed individuals showed the expected preference for similar mates, but stressed individuals seem to prefer dissimilar mates. PMID:20219732

  19. Evolution of mating systems in coral reef gobies and constraints on mating system plasticity

    NASA Astrophysics Data System (ADS)

    Hernaman, V.; Munday, P. L.

    2007-09-01

    Social and mating systems can be influenced by the distribution, abundance, and economic defendability of breeding partners and essential resources. Polygyny is predicted where males can economically defend multiple females or essential resources used by females. In contrast, monogamy is predicted where neither sex can monopolise multiple partners, either directly or through resource control, but where one mate is economically defendable. The mating system and reproductive behaviour of five species of coral reef goby were investigated and contrasted with population density and individual mobility. The two most abundant species ( Asterropteryx semipunctatus and Istigobius goldmanni) were polygynous. In contrast, the less populous and more widely dispersed epibenthic species ( Amblygobius bynoensis, Amblygobius phalaena and Valenciennea muralis) were pair forming and monogamous. All five species had low mobility, mostly remaining within metres (3 epibenthic species) or centimetres (2 cryptobenthic species) of a permanent shelter site. Interspecific differences in the mating system may have been shaped by differences in population density and the ability of reproductive individuals to economically defend breeding partners/sites. However, in a test of mating system plasticity, males of the three monogamous species did not mate polygynously when given the opportunity to do so in experimental manipulations of density and sex ratio. Mate guarding and complex spawning characteristics, which have likely co-evolved with the monogamous mating system, could contribute to mating system inflexibility by making polygynous mating unprofitable for individuals of the pair forming species, even when presented with current-day ecological conditions that usually favour polygyny.

  20. Fertility of yearling beef bulls during mating.

    PubMed

    Ellis, R W; Rupp, G P; Chenoweth, P J; Cundiff, L V; Lunstra, D D

    2005-08-01

    Crossbred (Bos taurus) yearling beef bulls were assessed for breeding soundness and physical traits prior to multi-sire natural mating at pasture. Bulls (n = 60) were assigned to six groups of nine or 10 bulls and two bull-groups were rotated on 14-day intervals during a 63-day mating season in each breeding herd (n = 3) of 191-196 cows. The remaining bulls (n = 14) were maintained under similar environmental conditions without mating exposure. Bulls were observed during mating and assessed for breeding soundness and changes following mating. Bulls used for breeding (UFB) lost 77 kg of body weight and declined from body condition scores of 6 to 4.5, whereas bulls not used for breeding (NUB) maintained body condition scores of 6 and gained 27 kg. The UFB bulls incurred a 75% total injury rate with 63% incidence of lameness and 12% incidence of reproductive injuries, resulting in a 22% attrition rate. Only 45% were physically sound at the end of mating. Scrotal circumference declined in UFB bulls (-4.58%) and increased in NUB bulls (2.49%). From the 98% BSE-satisfactory rate (UFB) prior to breeding, only 61% were BSE-satisfactory post-breeding. The NUB bulls declined from 57 to 36% satisfactory. The BSE classification was influenced by significant increases in abnormal spermatozoa (primary and secondary), which was significantly associated with injuries incurred during mating. Group and breed differences in injury rates and BSE-status following mating were evident. Environmental conditions and mating activity influenced bull seminal quality and physical condition. Pregnancy rates in all three breeding herds (91-96%) were similar, with insignificant differences between bull-groups; the effects of physical and reproductive changes on individual bull fertility were immeasurable.

  1. Cloning of a serotype-specific antigen from Pasteurella haemolytica A1.

    PubMed Central

    Gonzalez-Rayos, C; Lo, R Y; Shewen, P E; Beveridge, T J

    1986-01-01

    Recombinant plasmids coding for a soluble (or surface) antigen of Pasteurella haemolytica A1 were identified. Two plasmids, both containing the same 5.4 kilobase pairs of insert DNA, were recovered independently by screening a clone band of P. haemolytica A1 genomic DNA in Escherichia coli for the expression of P. haemolytica A1 soluble antigens (R. Y. C. Lo and L.A. Cameron, Can. J. Biochem. Cell Biol. 64:73-76, 1986). E. coli cells carrying the plasmids were found to be agglutinated by an antiserum raised against the P. haemolytica A1 soluble antigens. Analysis of the E. coli clones by electron microscopy revealed patches of amorphous material on the surface of the cells which were not present on the controls. Further characterization with protein A-colloidal gold labeled both these patches and the outer membranes of these cloned cells pretreated with the specific antiserum. These results indicated that the cloned antigen was expressed on the surface of the E. coli cells. The cloned antigen was found to be specific for serotype 1 when tested by slide agglutination against a collection of P. haemolytica typing antisera. Southern blot hybridization, using the cloned DNA as a probe, labeled the genomic DNA from P. haemolytica serotype 1 as well as the cross-agglutinating serotypes 2 and 7, but not DNA from the non-cross-agglutinating serotypes 3 and 4 and Pasteurella multocida. These results demonstrated that serotype specificity could be attributed to the particular antigenic determinants in the genome of the organism. Images PMID:3527985

  2. Serotype, virulence, and genetic traits of foodborne and clinical Vibrio parahaemolyticus isolates in Shanghai, China.

    PubMed

    Zhang, Hongzhi; Sun, Shuangfu; Shi, Weimin; Cui, Lin; Gu, Qifang

    2013-09-01

    Vibrio parahaemolyticus is a major foodborne pathogen in China and other countries. In this study, a total of 578 clinical V. parahaemolyticus strains and 51 foodborne strains were isolated during the period from 2009 to 2011 in the eastern coastal city of Shanghai, China. Their serotypes, virulence genes, pandemic traits, and genotyping were investigated. A total of nine O groups and 20 K types were identified by serological analysis of all isolates. Six different O groups and 14 different K types were detected among the 578 clinical strains. Eight different O groups and five K types were detected among the 51 foodborne strains. The O3:K6 serotype was the dominant serotype. A total of 200 representative clinical strains and 51 foodborne isolates were analyzed for virulence genes, pandemic traits, and genotyping. Of the clinical strains, 92.5% had the virulence genes tdh and/or trh. Four foodborne isolates had virulence genes; one trh-positive strain was O3:K6 and three tdh-positive strains were either O4:KUT or O3:KUT. Molecular typing by pulsed-field gel electrophoresis also showed divergence among the nonpandemic strains, although the pandemic strains formed a cluster. These results suggest high serodiversity and genetic diversity of V. parahaemolyticus. Pathogenic isolates were present in food, thus representing a public health risk and warranting epidemiological and ecological monitoring to ensure safety.

  3. Endocrinology of human female sexuality, mating, and reproductive behavior.

    PubMed

    Motta-Mena, Natalie V; Puts, David A

    2016-11-17

    Hormones orchestrate and coordinate human female sexual development, sexuality, and reproduction in relation to three types of phenotypic changes: life history transitions such as puberty and childbirth, responses to contextual factors such as caloric intake and stress, and cyclical patterns such as the ovulatory cycle. Here, we review the endocrinology underlying women's reproductive phenotypes, including sexual orientation and gender identity, mate preferences, competition for mates, sex drive, and maternal behavior. We highlight distinctive aspects of women's sexuality such as the possession of sexual ornaments, relatively cryptic fertile windows, extended sexual behavior across the ovulatory cycle, and a period of midlife reproductive senescence-and we focus on how hormonal mechanisms were shaped by selection to produce adaptive outcomes. We conclude with suggestions for future research to elucidate how hormonal mechanisms subserve women's reproductive phenotypes.

  4. Simple Model of Mating Preference and Extinction Risk

    NASA Astrophysics Data System (ADS)

    PȨKALSKI, Andrzej

    We present a simple model of a population of individuals characterized by their genetic structure in the form of a double string of bits and the phenotype following from it. The population is living in an unchanging habitat preferring a certain type of phenotype (optimum). Individuals are unisex, however a pair is necessary for breeding. An individual rejects a mate if the latter's phenotype contains too many bad, i.e. different from the optimum, genes in the same places as the individual's. We show that such strategy, analogous to disassortative mating based on the major histocompatibility complex, avoiding inbreeding and incest, could be beneficial for the population and could reduce considerably the extinction risk, especially in small populations.

  5. Mechanical seal having a single-piece, perforated mating ring

    DOEpatents

    Khonsari, Michael M.; Somanchi, Anoop K.

    2007-08-07

    A mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) with reduced contact surface temperature, reduced contact surface wear, or increased life span. The mechanical seal comprises a rotating ring and a single-piece, perforated mating ring, which improves heat transfer by controllably channeling coolant flow through the single-piece mating ring such that the coolant is in substantially uniform thermal contact with a substantial portion of the interior surface area of the seal face, while maintaining the structural integrity of the mechanical seal and minimizing the potential for coolant flow interruptions to the seal face caused by debris or contaminants (e.g., small solids and trash) in the coolant.

  6. Multi-Serotype Pneumococcal Nasopharyngeal Carriage Prevalence in Vaccine Naïve Nepalese Children, Assessed Using Molecular Serotyping

    PubMed Central

    Kandasamy, Rama; Gurung, Meeru; Thapa, Anushil; Ndimah, Susan; Adhikari, Neelam; Murdoch, David R.; Kelly, Dominic F.; Waldron, Denise E.; Gould, Katherine A.; Thorson, Stephen; Shrestha, Shrijana; Hinds, Jason; Pollard, Andrew J.

    2015-01-01

    Invasive pneumococcal disease is one of the major causes of death in young children in resource poor countries. Nasopharyngeal carriage studies provide insight into the local prevalence of circulating pneumococcal serotypes. There are very few data on the concurrent carriage of multiple pneumococcal serotypes. This study aimed to identify the prevalence and serotype distribution of pneumococci carried in the nasopharynx of young healthy Nepalese children prior to the introduction of a pneumococcal conjugate vaccine using a microarray-based molecular serotyping method capable of detecting multi-serotype carriage. We conducted a cross-sectional study of healthy children aged 6 weeks to 24 months from the Kathmandu Valley, Nepal between May and October 2012. Nasopharyngeal swabs were frozen and subsequently plated on selective culture media. DNA extracts of plate sweeps of pneumococcal colonies from these cultures were analysed using a molecular serotyping microarray capable of detecting relative abundance of multiple pneumococcal serotypes. 600 children were enrolled into the study: 199 aged 6 weeks to <6 months, 202 aged 6 months to < 12 months, and 199 aged 12 month to 24 months. Typeable pneumococci were identified in 297/600 (49·5%) of samples with more than one serotype being found in 67/297 (20·2%) of these samples. The serotypes covered by the thirteen-valent pneumococcal conjugate vaccine were identified in 44·4% of samples containing typeable pneumococci. Application of a molecular serotyping approach to identification of multiple pneumococcal carriage demonstrates a substantial prevalence of co-colonisation. Continued surveillance utilising this approach following the introduction of routine use of pneumococcal conjugate vaccinates in infants will provide a more accurate understanding of vaccine efficacy against carriage and a better understanding of the dynamics of subsequent serotype and genotype replacement. PMID:25643355

  7. Homosexual mating preferences from an evolutionary perspective: sexual selection theory revisited.

    PubMed

    Gobrogge, Kyle L; Perkins, Patrick S; Baker, Jessica H; Balcer, Kristen D; Breedlove, S Marc; Klump, Kelly L

    2007-10-01

    Studies in evolutionary psychology and sexual selection theory show that heterosexual men prefer younger mating partners than heterosexual women in order to ensure reproductive success. However, previous research has generally not examined differences in mating preferences as a function of sexual orientation or the type of relationship sought in naturalistic settings. Given that homosexual men seek partners for reasons other than procreation, they may exhibit different mating preferences than their heterosexual counterparts. Moreover, mating preferences may show important differences depending on whether an individual is seeking a long-term versus a short-term relationship. The purpose of the present study was to examine these issues by comparing partner preferences in terms of age and relationship type between homosexual and heterosexual men placing internet personal advertisements. Participants included 439 homosexual and 365 heterosexual men who placed internet ads in the U.S. or Canada. Ads were coded for the participant's age, relationship type (longer-term or short-term sexual encounter) sought, and partner age preferences. Significantly more homosexual than heterosexual men sought sexual encounters, although men (regardless of sexual orientation) seeking sexual encounters preferred a significantly wider age range of partners than men seeking longer-term relationships. These findings suggest that partner preferences are independent of evolutionary drives to procreate, since both types of men preferred similar ages in their partners. In addition, they highlight the importance of examining relationship type in evolutionary studies of mating preferences, as men's partner preferences show important differences depending upon the type of relationship sought.

  8. Probability of identifying different salmonella serotypes in poultry samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent work has called attention to the unequal competitive abilities of different Salmonella serotypes in standard broth culture and plating media. Such serotypes include Enteritidis and Typhimurium that are specifically targeted in some regulatory and certification programs because they cause a l...

  9. First Complete Genome Sequence of Haemophilus influenzae Serotype a

    PubMed Central

    Hayden, Kristy

    2017-01-01

    ABSTRACT Haemophilus influenzae is an important human pathogen that primarily infects small children. In recent years, H. influenzae serotype a has emerged as a significant cause of invasive disease among indigenous populations. Here, we present the first complete whole-genome sequence of H. influenzae serotype a. PMID:28104664

  10. Nomenclature of human rotaviruses: designation of subgroups and serotypes*

    PubMed Central

    1984-01-01

    Based on the specificity of subgroup antigens and serotype antigens which are situated, respectively, in the major inner and outer capsid polypeptides, a new nomenclature for human rotaviruses is proposed. The subgroups are designated as I and II, and the serotypes as 1, 2, 3, 4. PMID:6088101

  11. Serotype sensitivity of a lateral flow immunoassay for cryptococcal antigen.

    PubMed

    Gates-Hollingsworth, Marcellene A; Kozel, Thomas R

    2013-04-01

    To meet the needs of a global community, an immunoassay for cryptococcal antigen (CrAg) must have high sensitivity for CrAg of all major serotypes. A new immunoassay for CrAg in lateral flow format was evaluated and found to have a high sensitivity for detection of serotypes A, B, C, and D.

  12. Polarization of yeast cells in spatial gradients of alpha mating factor.

    PubMed Central

    Segall, J E

    1993-01-01

    The process of cell fusion during mating of the yeast Saccharomyces cerevisiae is mediated by factors secreted by the mating partners. Spatial gradients of one of these mating factors, alpha-factor, polarized the growth of projections by MATa cells. The site of previous budding did not affect the direction of polarization, and subsequent budding was also polarized if mating factor was removed. Orientation occurred in the presence of nocodazole, suggesting that microtubules were not critical. At extremely low concentrations of alpha-factor, sst2-mutants (which in genetic studies do not discriminate between partners producing different amounts of alpha-factor) were able to polarize their projections. The sensitivity of this spatial sensing mechanism in wild-type cells is such that differences in receptor occupancy estimated to be about 1% are sufficient for orientation. Images Fig. 1 Fig. 2 Fig. 3 PMID:8397402

  13. Equilibrium population dynamics when mating is by mutual choice based on age.

    PubMed

    Alpern, Steve; Katrantzi, Ioanna; Ramsey, David

    2014-06-01

    We consider a steady state model of mutual mate choice in which an individual's mate preferences depend on his/her age, and the preferences are over the ages of prospective mates of the opposite sex. We present a discrete time (and age) model corresponding to successive mating seasons. Males are fertile for m periods (corresponding to 'age' i=1 to m) and females for n≤m periods (they have ages j=1 to n), which is all that distinguishes the sexes. Although we can deal with arbitrary preferences, we concentrate on a simple fertility model where the common utility to a male age i and female age j who mate is the number K=min(m-i+1,n-j+1) of future periods of joint fertility. The incoming sex ratio R of age 1 males to age 1 females is given exogenously. In each period individuals are randomly (non assortatively) matched and form a mated couple by mutual consent; otherwise they go into the next period unmated and older. We derive properties of equilibrium threshold acceptance strategies and establish the existence of time-invariant age distributions. Our methods determine the age distribution of couples at marriage (mating) and the population sex ratio (OSR) at equilibrium. Since this can be determined empirically in a population, our model can be used to rule out most systems of age preferences (those not consistent with the observed distribution). This extends earlier models of mutual choice with one dimensional types of Alpern and Reyniers [1999. Strategic mating with homotypic preferences. J. Theor. Biol. 198, 71-88; 2005. Strategic mating with common preferences. J. Theor. Biol. 237, 337-354] where individuals sought, respectively, individuals with similar or high types, but in those models an individual's type was fixed over time. Under the simple fertility model, at equilibrium the maximum age of an acceptable partner is increasing in the age of the searcher. Our results relate to discussions in the literature regarding optimal parental age differences, age

  14. Salmonella serotypes in reptiles and humans, French Guiana.

    PubMed

    Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

    2014-05-14

    In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment.

  15. Assortative mating based on cooperativeness and generosity.

    PubMed

    Tognetti, A; Berticat, C; Raymond, M; Faurie, C

    2014-05-01

    Cooperative behaviour and generosity towards nonkin represent costly and risky behaviour that could be used as a signal of mate quality. Therefore, cooperative traits could serve as criteria in mate choice, leading to assortative mating for those traits. There is evidence of similarity in couples for altruistic traits. However, the literature is based on self-reports and does not provide conclusive proof of either a convergence across time or mating preferences. Here, we report a field experiment, conducted in rural villages in Senegal, showing that husbands and wives are similar with respect to their contributions to a public good and their charity donations. Further analyses suggest that this similarity is due to initial assortment rather than convergence of phenotypes.

  16. Mating behaviour: promiscuous mothers have healthier young.

    PubMed

    Edvardsson, Martin; Champion de Crespigny, Fleur E; Tregenza, Tom

    2007-01-23

    A small marsupial has thrown new light on the question of why females typically mate with several males: promiscuous female antechinuses have many more surviving offspring because males that are successful in sperm competition also sire healthy offspring.

  17. Effect of Mating Status and Age on the Male Mate Choice and Mating Competency in the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae).

    PubMed

    Wang, Desen; Wang, Changlu; Singh, Narinderpal; Cooper, Richard; Zha, Chen; Eiden, Amanda L

    2016-04-28

    We investigated male mate choice and mating competency in the common bed bug, Cimex lectularius L., using video tracking for 10 min per experiment. In the male mate choice experiment, when a male was placed with two females of different mating status, males preferred to initiate copulation with the virgin female more quickly than with the mated female, and the mean total copulation duration with virgin females (38.0 ± 3.0 s) was significantly longer than with mated females (14.6 ± 3.0 s). When a male was placed with two females of different age, males initiated copulation more quickly with the old virgin female (29-34 d adult emergence) than with the young virgin one (<7 d adult emergence), and the mean total copulation duration with old virgin females (38.4 ± 4.0 s) was significantly longer than with young virgin females (24.0 ± 3.0 s). In the male mating competency experiment where a female was placed with two males of different mating status or age, the virgin males were more eager to mate than the mated males, and the old virgin males (29-34 d adult emergence) were more eager than the young virgin males (<7 d adult emergence), with eagerness measured by the percentage of first mate selected (first copulation occurred) and the total copulation duration by each group of males. Male mating competency is related to postmating duration (PMD); males mated 1 d earlier were significantly less likely to mate than virgin males. However, males mated 7 d earlier showed no significant difference in mating competency compared to virgin males. In conclusion, mate choice in C. lectularius is associated with both male and female mating status, age, and PMD.

  18. Associations between body morphology, mating success and mate preferences among Slovak males and females.

    PubMed

    Prokop, Pavol; Fedor, Peter

    2013-01-01

    Human body morphology is thought to be correlated with sexual behaviour and sociosexuality (defined as an increased willingness to engage in sex without commitment) influences the perception of certain cues of physical attractiveness. Based on a sample of Slovak university students, we investigated relationships between 1) male and female mating success and reported body morphology (body mass index, BMI and waist-to-hip ratio, WHR) and 2) mate preference characteristics and mating success. Both males and females reported a similar number of long-term sexual partners and frequency of engaging in extra-pair copulation (EPC). The mating success of both sexes was positively mediated by self-perceived attractiveness. However, female BMI was inversely associated with mating success whereas increasing BMI was positively associated with male mating success (the total number of lifetime sexual partners) as well as with the likelihood of engaging in EPC. Unrestricted sociosexuality positively correlated with direct and indirect benefits from mating and negatively with the religious/political background of a potential mate and with the desire for a home/ children. These results confirm the hypothesis that human body morphology is associated with sexual behaviour and that cues of direct/indirect benefits in a potential mate positively correlate with sociosexuality.

  19. Mating scars reveal mate size in immature female blue shark Prionace glauca.

    PubMed

    Calich, H J; Campana, S E

    2015-06-01

    The objective of this study was to determine the size and maturity status of the male blue sharks Prionace glauca attempting to mate with small, immature females in the north-west Atlantic Ocean. The relationship between male curved fork length (LFC ) and jaw gape was used in conjunction with the diameter of the mating scar to estimate the LFC and infer the maturity status of the male shark that produced the mating scar. The results indicate that mature males with a mean ± s.d. LFC of 218 cm ± 23 cm were attempting to mate with sexually immature females.

  20. Advanced Mating System Development for Space Applications

    NASA Technical Reports Server (NTRS)

    Lewis, James L.

    2004-01-01

    This slide presentation reviews the development of space flight sealing and the work required for the further development of a dynamic interface seal for the use on space mating systems to support a fully androgynous mating interface. This effort has resulted in the advocacy of developing a standard multipurpose interface for use with all modern modular space architecture. This fully androgynous design means a seal-on-seal (SOS) system.

  1. Potent immune responses and in vitro pro-inflammatory cytokine suppression by a novel adenovirus vaccine vector based on rare human serotype 28.

    PubMed

    Kahl, Christoph A; Bonnell, Jessica; Hiriyanna, Suja; Fultz, Megan; Nyberg-Hoffman, Cassandra; Chen, Ping; King, C Richter; Gall, Jason G D

    2010-08-09

    Adenovirus vaccine vectors derived from rare human serotypes have been shown to be less potent than serotype 5 (Ad5) at inducing immune responses to encoded antigens. To identify highly immunogenic adenovirus vectors, we assessed pro-inflammatory cytokine expression, binding to the CD46 receptor, and immunogenicity. Species D adenoviruses uniquely suppressed pro-inflammatory cytokines and induced high levels of type I interferon. Thus, it was unexpected that a vector derived from a representative serotype, Ad28, induced significantly higher transgene-specific T cell responses than an Ad35 vector. Prime-boost regimens with Ad28, Ad35, Ad14, or Ad5 significantly boosted T cell and antibody responses. The seroprevalence of Ad28 was confirmed to be <10% in the United States. Together, this shows that a rare human serotype-based vector can elicit strong immune responses, which was not predicted by in vitro results.

  2. Draft Genome Sequence of an Atypical Strain of Streptococcus pneumoniae Serotype 19A Isolated from Cerebrospinal Fluid

    PubMed Central

    Hinojosa-Robles, Rosa Maria; Barcenas-Walls, Jose Ramon; Rojas-Martinez, Augusto; Barrera-Saldaña, Hugo Alberto

    2016-01-01

    We present here the draft genome sequence of Streptococcus pneumoniae strain MTY32702340SN814 isolated in Monterrey, Mexico, from a girl with bacterial meningitis. The strain belongs to the atypical and multidrug-resistant serogroup 19A. This is the first report in the literature of sequence type 3936 (ST3936) in S. pneumoniae serotype 19A. PMID:27103715

  3. Mating behavior and the evolution of sperm design

    PubMed Central

    Schärer, Lukas; Littlewood, D. Timothy J.; Waeschenbach, Andrea; Yoshida, Wataru; Vizoso, Dita B.

    2011-01-01

    Sperm are the most diverse of all animal cell types, and much of the diversity in sperm design is thought to reflect adaptations to the highly variable conditions under which sperm function and compete to achieve fertilization. Recent work has shown that these conditions often evolve rapidly as a consequence of multiple mating, suggesting a role for sexual selection and sexual conflict in the evolution of sperm design. However, very little of the striking diversity in sperm design is understood functionally, particularly in internally fertilizing organisms. We use phylogenetic comparative analyses covering 16 species of the hermaphroditic flatworm genus Macrostomum to show that a complex sperm design is associated with reciprocal mating and that this complexity is lost secondarily when hypodermic insemination—sperm injection through the epidermis—evolves. Specifically, the complex sperm design, which includes stiff lateral bristles, is likely a male persistence trait associated with sexual conflicts over the fate of received ejaculates and linked to female resistance traits, namely an intriguing postcopulatory sucking behavior and a thickened epithelium of the sperm-receiving organ. Our results suggest that the interactions between sperm donor, sperm, and sperm recipient can change drastically when hypodermic insemination evolves, involving convergent evolution of a needle-like copulatory organ, a simpler sperm design, and a simpler female genital morphology. Our study documents that a shift in the mating behavior may alter fundamentally the conditions under which sperm compete and thereby lead to a drastic change in sperm design. PMID:21220334

  4. In vivo cross-protection to African horse sickness Serotypes 5 and 9 after vaccination with Serotypes 8 and 6.

    PubMed

    von Teichman, Beate F; Dungu, Baptiste; Smit, Theresa K

    2010-09-07

    The polyvalent African horsesickness (AHS) attenuated live virus (AHS-ALV) vaccine produced at Onderstepoort Biological Products incorporates 7 of the 9 known serotypes circulating in southern Africa. Serological cross-reaction has been shown in vitro to Serotypes 5 and 9 by Serotypes 8 and 6 respectively, but the degree of in vivo cross-protection between these serotypes in vaccinated horses has not previously been reported. Due to the increasing incidence of AHS Serotypes 5 and 9 in the field, over the last 3-4 seasons of AHS in South Africa, and the absence of Serotypes 5 and 9 in the AHS-ALV vaccine, it was necessary to conduct a vaccination-challenge study to determine in vivo cross-protection of vaccine-incorporated Serotypes 8 and 6 respectively. Groups of horses were vaccinated with either the polyvalent AHS-ALV vaccine or a monovalent Serotype 6 (vAHSV6) or 8 (vAHSV8) vaccine to determine the cross-protection of vaccinated horses following challenge with virulent AHS virus (AHSV) of either Serotype 5, 6, 8 or 9. Serial vaccination of naive horses with the polyvalent AHS-ALV vaccine generated a broad neutralizing antibody response to all vaccine strains as well as cross-neutralizing antibodies to Serotypes 5 and 9. Booster vaccination of horses with monovalent vaccine vAHSV6 or vAHSV8 induced an adequate protective immune response to challenge with homologous and heterologous virulent virus. In vivo cross-protection between AHSV6 and AHSV9 and AHSV8 and AHSV5 respectively, was demonstrated.

  5. Mating-related behaviour of grizzly bears inhabiting marginal habitat at the periphery of their North American range.

    PubMed

    Edwards, Mark A; Derocher, Andrew E

    2015-02-01

    In comparison to core populations, peripheral populations have low density and recruitment, and are subject to different selective pressures, such as environmental conditions, food type and availability, predation, disease, etc., which may result in behavioural modifications to mating. We test the roam-to-mate hypothesis for a peripheral population of grizzly bears (Ursus arctos) at the northern extent of their North American range, in Canada's Arctic. If bears are roaming-to-mate, we predicted greater range size and daily displacement, and more linear movements for receptive animals during the mating period compared to post-mating. In contrast to our predictions, we found that in general range size and displacement increased from mating to post-mating regardless of reproductive status. When considered across both periods, females with cubs-of-the-year had smaller range use metrics than other reproductive groups, which we attribute to a counter-strategy against sexually selected infanticide and the reduced mobility of cubs. Linearity of movements remained near zero during both periods across all groups, suggesting tortuous movements more characteristic of foraging than of mate-searching. We suggest that for this population, finding quality habitat takes precedence over mate-searching in this marginal Arctic landscape. Alternatively, a more monogamous mating system and sequestering behaviour may have obscured movement differences between the two periods. The behavioural differences in mating that we observed from what is typical of core populations may reflect local adaptation to marginal conditions and could benefit the species in the face of ongoing environmental change.

  6. Assortative mating between two sympatric closely-related specialists: inferred from molecular phylogenetic analysis and behavioral data.

    PubMed

    Xue, Huai-Jun; Li, Wen-Zhu; Yang, Xing-Ke

    2014-06-25

    Host plant shifting of phytophagous insects can lead to the formation of host associated differentiation and ultimately speciation. In some cases, host plant specificity alone acts as a nearly complete pre-mating isolating barrier among insect populations. We here test whether effective pre-mating isolation and host-independent behavioral isolation have evolved under the condition of extreme host specilization using two sympatric flea beetles with incomplete post-mating isolation under laboratory conditions. Phylogenetic analysis and coalescent simulation results showed that there is a limited interspecific gene flow, indicating effctive isolation between these species. Three types of mating tests in the absence of host plant cues showed that strong host-independent behavioral isolation has evolved between them. We conclude that almost perfect assortative mating between these two extreme host specialists results from a combination of reduced encounter rates due to differential host preference and strong sexual isolation.

  7. Assortative mating between two sympatric closely-related specialists: inferred from molecular phylogenetic analysis and behavioral data

    PubMed Central

    Xue, Huai-Jun; Li, Wen-Zhu; Yang, Xing-Ke

    2014-01-01

    Host plant shifting of phytophagous insects can lead to the formation of host associated differentiation and ultimately speciation. In some cases, host plant specificity alone acts as a nearly complete pre-mating isolating barrier among insect populations. We here test whether effective pre-mating isolation and host-independent behavioral isolation have evolved under the condition of extreme host specilization using two sympatric flea beetles with incomplete post-mating isolation under laboratory conditions. Phylogenetic analysis and coalescent simulation results showed that there is a limited interspecific gene flow, indicating effctive isolation between these species. Three types of mating tests in the absence of host plant cues showed that strong host-independent behavioral isolation has evolved between them. We conclude that almost perfect assortative mating between these two extreme host specialists results from a combination of reduced encounter rates due to differential host preference and strong sexual isolation. PMID:24961567

  8. Mate competition and evolutionary outcomes in genetically modified zebrafish (Danio rerio).

    PubMed

    Howard, Richard D; Rohrer, Karl; Liu, Yiyang; Muir, William M

    2015-05-01

    Demonstrating relationships between sexual selection mechanisms and trait evolution is central to testing evolutionary theory. Using zebrafish, we found that wild-type males possessed a significant advantage in mate competition over transgenic RFP Glofish® males. In mating trials, wild-type males were aggressively superior to transgenic males in male-male chases and male-female chases; as a result, wild-type males sired 2.5× as many young as did transgenic males. In contrast, an earlier study demonstrated that female zebrafish preferred transgenic males as mates when mate competition was excluded experimentally. We tested the evolutionary consequence of this conflict between sexual selection mechanisms in a long-term study. The predicted loss of the transgenic phenotype was confirmed. More than 18,500 adults collected from 18 populations across 15 generations revealed that the frequency of the transgenic phenotype declined rapidly and was eliminated entirely in all but one population. Fitness component data for both sexes indicated that only male mating success differed between wild-type and transgenic individuals. Our predictive demographic model based on fitness components closely matched the rate of transgenic phenotype loss observed in the long-term study, thereby supporting its utility for studies assessing evolutionary outcomes of escaped or released genetically modified animals.

  9. Sexual selection and assortative mating: an experimental test.

    PubMed

    Debelle, A; Ritchie, M G; Snook, R R

    2016-07-01

    Mate choice and mate competition can both influence the evolution of sexual isolation between populations. Assortative mating may arise if traits and preferences diverge in step, and, alternatively, mate competition may counteract mating preferences and decrease assortative mating. Here, we examine potential assortative mating between populations of Drosophila pseudoobscura that have experimentally evolved under either increased ('polyandry') or decreased ('monogamy') sexual selection intensity for 100 generations. These populations have evolved differences in numerous traits, including a male signal and female preference traits. We use a two males: one female design, allowing both mate choice and competition to influence mating outcomes, to test for assortative mating between our populations. Mating latency shows subtle effects of male and female interactions, with females from the monogamous populations appearing reluctant to mate with males from the polyandrous populations. However, males from the polyandrous populations have a significantly higher probability of mating regardless of the female's population. Our results suggest that if populations differ in the intensity of sexual selection, effects on mate competition may overcome mate choice.

  10. Serotypes and Antibiotic Susceptibility of Streptococcus pneumoniae Isolates from Invasive Pneumococcal Disease and Asymptomatic Carriage in a Pre-vaccination Period, in Algeria.

    PubMed

    Ziane, Hanifa; Manageiro, Vera; Ferreira, Eugénia; Moura, Inês B; Bektache, Soumia; Tazir, Mohamed; Caniça, Manuela

    2016-01-01

    In Algeria, few data is available concerning the distribution of pneumococcal serotypes and respective antibiotic resistance for the current pre-vaccination period, which is a public health concern. We identified the most frequent Streptococcus pneumoniae serogroup/types implicated in invasive pneumococcal disease (IPD; n = 80) and carriage (n = 138) in Algerian children younger than 5 years old. Serogroup/types of 78 IPD isolates were identified by capsular typing using a sequential multiplex PCR. Overall, serotypes 14, 19F, 6B, 23F, 18C, 1, 5, 7F, 19A, and 3 (55% of PCV7 serotypes, 71.3% of PCV10, and 90% of PCV13) were identified. Additionally, 7.5% of the non-vaccine serotypes 6C, 9N/L, 20, 24F, 35B, and 35F, were observed. In the case of S. pneumoniae asymptomatic children carriers, the most common serogroup/types were 6B, 14, 19F, 23F, 4, 9V/A, 1, 19A, 6A, and 3 (42.7% of PCV7 serotypes, 44.2% of PCV10, and 58% of PCV13). For 6.1% of the cases co-colonization was detected. Serotypes 14, 1, 5, and 19A were more implicated in IPD (p < 0.01), whereas serotype 6A was exclusively isolated from carriers (p < 0.01). Deaths associated with IPD were related to serotypes 19A, 14, 18C, and one non-typeable isolate. Among IPD related to vaccine serotypes, the rates of penicillin non-susceptible isolates were higher in no meningitis cases (80%) than in meningitis (66.7%), with serotypes 14, 19A, 19F, and 23F presenting the highest MIC levels (>2μg/ml). Resistance to cefotaxime was higher in isolates from meningitis (40.5%); however, resistance to erythromycin and co-trimoxazole (>40%) was more pronounced in no-meningeal forms. Overall, our results showed that PCV13 conjugate vaccine would cover up to 90% of the circulating isolates associated with IPD in Algeria, highlighting the importance of monitoring the frequency of S. pneumoniae serogroups/types during pre- and post-vaccination periods.

  11. Serotypes and Antibiotic Susceptibility of Streptococcus pneumoniae Isolates from Invasive Pneumococcal Disease and Asymptomatic Carriage in a Pre-vaccination Period, in Algeria

    PubMed Central

    Ziane, Hanifa; Manageiro, Vera; Ferreira, Eugénia; Moura, Inês B.; Bektache, Soumia; Tazir, Mohamed; Caniça, Manuela

    2016-01-01

    In Algeria, few data is available concerning the distribution of pneumococcal serotypes and respective antibiotic resistance for the current pre-vaccination period, which is a public health concern. We identified the most frequent Streptococcus pneumoniae serogroup/types implicated in invasive pneumococcal disease (IPD; n = 80) and carriage (n = 138) in Algerian children younger than 5 years old. Serogroup/types of 78 IPD isolates were identified by capsular typing using a sequential multiplex PCR. Overall, serotypes 14, 19F, 6B, 23F, 18C, 1, 5, 7F, 19A, and 3 (55% of PCV7 serotypes, 71.3% of PCV10, and 90% of PCV13) were identified. Additionally, 7.5% of the non-vaccine serotypes 6C, 9N/L, 20, 24F, 35B, and 35F, were observed. In the case of S. pneumoniae asymptomatic children carriers, the most common serogroup/types were 6B, 14, 19F, 23F, 4, 9V/A, 1, 19A, 6A, and 3 (42.7% of PCV7 serotypes, 44.2% of PCV10, and 58% of PCV13). For 6.1% of the cases co-colonization was detected. Serotypes 14, 1, 5, and 19A were more implicated in IPD (p < 0.01), whereas serotype 6A was exclusively isolated from carriers (p < 0.01). Deaths associated with IPD were related to serotypes 19A, 14, 18C, and one non-typeable isolate. Among IPD related to vaccine serotypes, the rates of penicillin non-susceptible isolates were higher in no meningitis cases (80%) than in meningitis (66.7%), with serotypes 14, 19A, 19F, and 23F presenting the highest MIC levels (>2μg/ml). Resistance to cefotaxime was higher in isolates from meningitis (40.5%); however, resistance to erythromycin and co-trimoxazole (>40%) was more pronounced in no-meningeal forms. Overall, our results showed that PCV13 conjugate vaccine would cover up to 90% of the circulating isolates associated with IPD in Algeria, highlighting the importance of monitoring the frequency of S. pneumoniae serogroups/types during pre- and post-vaccination periods. PMID:27379023

  12. The relationship between pneumococcal serotypes and antibiotic resistance.

    PubMed

    Song, Jae-Hoon; Dagan, Ron; Klugman, Keith P; Fritzell, Bernard

    2012-04-05

    Streptococcus pneumoniae (SP) causes significant burden of disease, including invasive pneumococcal disease and noninvasive diseases such as pneumonia and acute otitis media. SP has at least 93 different capsular serotypes, with the various serotypes having different propensities for producing disease or developing antibiotic resistance. An increase in the prevalence of antibiotic-resistant SP serotypes has been observed globally. The objective of this paper was to examine the relationship between antibiotic resistance and SP serotypes, with a primary focus on studies published in the past 10 years. Changing trends in antibiotic resistance and serotype distribution during this time, including those before and after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7), were analyzed. Factors that influence the prevalence of antibiotic-resistant serotypes include antibiotic selection pressure, the use of PCV7, and the emergence and spread of antibiotic-resistant clones. The emergence of multidrug resistant serotype 19A is of particular concern. Antibiotic-resistant SP is a global problem that must be addressed through multiple strategies, including national vaccination programs, antibiotic control programs, and ongoing surveillance.

  13. Advances in molecular serotyping and subtyping of Escherichia coli

    SciTech Connect

    Fratamico, Pina M.; DebRoy, Chitrita; Liu, Yanhong; Needleman, David S.; Baranzoni, Gian Marco; Feng, Peter

    2016-05-03

    Escherichia coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtyping and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS) of E. coli is replacing established subtyping methods such as pulsedfield gel electrophoresis, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. Furthermore, a variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.

  14. Pathogenic diversity amongst serotype C VGIII and VGIV Cryptococcus gattii isolates.

    PubMed

    Rodrigues, Jéssica; Fonseca, Fernanda L; Schneider, Rafael O; Godinho, Rodrigo M da C; Firacative, Carolina; Maszewska, Krystyna; Meyer, Wieland; Schrank, Augusto; Staats, Charley; Kmetzsch, Livia; Vainstein, Marilene H; Rodrigues, Marcio L

    2015-07-08

    Cryptococcus gattii is one of the causative agents of human cryptococcosis. Highly virulent strains of serotype B C. gattii have been studied in detail, but little information is available on the pathogenic properties of serotype C isolates. In this study, we analyzed pathogenic determinants in three serotype C C. gattii isolates (106.97, ATCC 24066 and WM 779). Isolate ATCC 24066 (molecular type VGIII) differed from isolates WM 779 and 106.97 (both VGIV) in capsule dimensions, expression of CAP genes, chitooligomer distribution, and induction of host chitinase activity. Isolate WM 779 was more efficient than the others in producing pigments and all three isolates had distinct patterns of reactivity with antibodies to glucuronoxylomannan. This great phenotypic diversity reflected in differential pathogenicity. VGIV isolates WM 779 and 106.97 were similar in their ability to cause lethality and produced higher pulmonary fungal burden in a murine model of cryptococcosis, while isolate ATCC 24066 (VGIII) was unable to reach the brain and caused reduced lethality in intranasally infected mice. These results demonstrate a high diversity in the pathogenic potential of isolates of C. gattii belonging to the molecular types VGIII and VGIV.

  15. Pathogenic diversity amongst serotype C VGIII and VGIV Cryptococcus gattii isolates

    PubMed Central

    Rodrigues, Jéssica; Fonseca, Fernanda L.; Schneider, Rafael O.; Godinho, Rodrigo M. da C.; Firacative, Carolina; Maszewska, Krystyna; Meyer, Wieland; Schrank, Augusto; Staats, Charley; Kmetzsch, Livia; Vainstein, Marilene H.; Rodrigues, Marcio L.

    2015-01-01

    Cryptococcus gattii is one of the causative agents of human cryptococcosis. Highly virulent strains of serotype B C. gattii have been studied in detail, but little information is available on the pathogenic properties of serotype C isolates. In this study, we analyzed pathogenic determinants in three serotype C C. gattii isolates (106.97, ATCC 24066 and WM 779). Isolate ATCC 24066 (molecular type VGIII) differed from isolates WM 779 and 106.97 (both VGIV) in capsule dimensions, expression of CAP genes, chitooligomer distribution, and induction of host chitinase activity. Isolate WM 779 was more efficient than the others in producing pigments and all three isolates had distinct patterns of reactivity with antibodies to glucuronoxylomannan. This great phenotypic diversity reflected in differential pathogenicity. VGIV isolates WM 779 and 106.97 were similar in their ability to cause lethality and produced higher pulmonary fungal burden in a murine model of cryptococcosis, while isolate ATCC 24066 (VGIII) was unable to reach the brain and caused reduced lethality in intranasally infected mice. These results demonstrate a high diversity in the pathogenic potential of isolates of C. gattii belonging to the molecular types VGIII and VGIV. PMID:26153364

  16. Characterization of Streptococcus pneumoniae invasive serotype 19A isolates recovered in Colombia.

    PubMed

    Ramos, Viviana; Parra, Eliana L; Duarte, Carolina; Moreno, Jaime

    2014-02-07

    The aim of this study was to determine the molecular characterization of invasive penicillin non-susceptible Streptococcus pneumoniae serotype 19A isolates, collected in Colombia between 1994 and 2012. A total of 115 isolates serotype 19A were analyzed. Genetic relationship of 80 isolates with minimal inhibitory concentration (MIC) to penicillin ≥0.125 μg/was determined by pulsed-field gel electrophoresis (PFGE) and selected strains were studied by multilocus sequence typing (MLST). Among the 115 isolates, resistance to penicillin in meningitis was 64.2%, in non-meningitis 32.2% were intermediate and 1.1% were high resistance. The most frequent sequence types were ST320 (33.7%), ST276 (21.5%), and ST1118 (11.2%). Five isolates were associated with the Spain(9V)-ST156 clone, and two isolates were related to Colombia(23F)-ST338 clone. S. pneumoniae serotype 19A increased in Colombia was associated with the spread of isolates genetically related to ST320 and ST276, and emergence of capsular variants of worldwide-disseminated clones.

  17. Mate-locating behavior of the butterfly Lethe diana (Lepidoptera: Satyridae): do males diurnally or seasonally change their mating strategy?

    PubMed

    Takeuchi, Tsuyoshi

    2010-10-01

    The mate-locating behavior of male butterflies has been classified into two major types, territorial and patrolling. Territorial males defend a specific site, whereas patrolling males fly around a wider area without having to defend a site. In this study, I investigated the use of these tactics by males of the satyrine butterfly, Lethe diana. A previous study suggested that the males of L. diana change their mate-locating behavior during the day (they patrol in the morning and defend territories in the afternoon) and that patrolling is the primary mating strategy, whereas defending territories is a supplementary one. In the present study, I found that the daily activity pattern of the males of L. diana was similar to that described in the previous study: males often flew around in the morning and competed for territories in the afternoon. However, contrary to the previous study, all courtships and copulations were performed within male territories during their territorial activity. Closer observations revealed that copulations found in male territories were achieved by the owner of the territory. Males tended to feed in the morning, suggesting that the males flying in the morning searched for food rather than females. I conclude that territory holding is the primary male matelocating tactic in L. diana. I further found that, in summer, males exhibited territorial behavior later than in spring or autumn, which may be a strategy for preventing heat stress.

  18. Analysis of the DNA-terminal protein from different serotypes of human adenovirus.

    PubMed Central

    Rekosh, D

    1981-01-01

    The DNA-terminal proteins from adenovirus type 12, type 3, and type 5 were analyzed after labeling in vitro with 125I by the chloramine T method, and were shown to be serotype specific. We also studied the kinetics of cleavage by alkali of the terminal protein-DNA linkage and showed that the half-time of cleavage with either 0.1 M NaOH or 0.5 M piperidine at 37 degree C is about 15 to 30 min. The substitution of the volatile base piperidine for NaOH in this procedure provided a useful tool for rapid analysis of the labeled protein. Images PMID:6895236

  19. Comparing pre- and post-copulatory mate competition using social network analysis in wild crickets

    PubMed Central

    Fisher, David N.; Rodríguez-Muñoz, Rolando

    2016-01-01

    Sexual selection results from variation in success at multiple stages in the mating process, including competition before and after mating. The relationship between these forms of competition, such as whether they trade-off or reinforce one another, influences the role of sexual selection in evolution. However, the relationship between these 2 forms of competition is rarely quantified in the wild. We used video cameras to observe competition among male field crickets and their matings in the wild. We characterized pre- and post-copulatory competition as 2 networks of competing individuals. Social network analysis then allowed us to determine 1) the effectiveness of precopulatory competition for avoiding postcopulatory competition, 2) the potential for divergent mating strategies, and 3) whether increased postcopulatory competition reduces the apparent reproductive benefits of male promiscuity. We found 1) limited effectiveness of precopulatory competition for avoiding postcopulatory competition; 2) males do not specifically engage in only 1 type of competition; and 3) promiscuous individuals tend to mate with each other, which will tend to reduce variance in reproductive success in the population and highlights the trade-off inherent in mate guarding. Our results provide novel insights into the works of sexual competition in the wild. Furthermore, our study demonstrates the utility of using network analyses to study competitive interactions, even in species lacking obvious social structure. PMID:27174599

  20. The Effect of Nonindependent Mate Pairing on the Effective Population Size

    PubMed Central

    Evans, Ben J.; Charlesworth, Brian

    2013-01-01

    The effective population size (Ne) quantifies the effectiveness of genetic drift in finite populations. When generations overlap, theoretical expectations for Ne typically assume that the sampling of offspring genotypes from a given individual is independent among successive breeding events, even though this is not true in many species, including humans. To explore the effects on Ne of nonindependent mate pairing across breeding events, we simulated the genetic drift of mitochondrial DNA, autosomal DNA, and sex chromosome DNA under three mating systems. Nonindependent mate pairing across breeding seasons has no effect when all adults mate pair for life, a small or moderate effect when females reuse stored sperm, and a large effect when there is intense male–male competition for reproduction in a harem social system. If adult females reproduce at a constant rate irrespective of the type of mate pairing, the general effect of nonindependent mate pairing is to decrease Ne for paternally inherited components of the genome. These findings have significant implications for the relative Ne values of different genomic regions, and hence for the expected levels of DNA sequence diversity in these regions. PMID:23183666

  1. Comparing pre- and post-copulatory mate competition using social network analysis in wild crickets.

    PubMed

    Fisher, David N; Rodríguez-Muñoz, Rolando; Tregenza, Tom

    2016-01-01

    Sexual selection results from variation in success at multiple stages in the mating process, including competition before and after mating. The relationship between these forms of competition, such as whether they trade-off or reinforce one another, influences the role of sexual selection in evolution. However, the relationship between these 2 forms of competition is rarely quantified in the wild. We used video cameras to observe competition among male field crickets and their matings in the wild. We characterized pre- and post-copulatory competition as 2 networks of competing individuals. Social network analysis then allowed us to determine 1) the effectiveness of precopulatory competition for avoiding postcopulatory competition, 2) the potential for divergent mating strategies, and 3) whether increased postcopulatory competition reduces the apparent reproductive benefits of male promiscuity. We found 1) limited effectiveness of precopulatory competition for avoiding postcopulatory competition; 2) males do not specifically engage in only 1 type of competition; and 3) promiscuous individuals tend to mate with each other, which will tend to reduce variance in reproductive success in the population and highlights the trade-off inherent in mate guarding. Our results provide novel insights into the works of sexual competition in the wild. Furthermore, our study demonstrates the utility of using network analyses to study competitive interactions, even in species lacking obvious social structure.

  2. Effects of sodium puddling on male mating success, courtship and flight in a swallowtail butterfly

    PubMed Central

    Mitra, Chandreyee; Reynoso, Edgar; Davidowitz, Goggy; Papaj, Daniel

    2016-01-01

    In many Lepidoptera species usually only males puddle for sodium. Two explanations have been offered for this: (1) neuromuscular activity: males need increased sodium for flight because they are more active flyers than females; and (2) direct benefits: sodium is a type of direct benefit provided by males to females via ejaculate during mating. Surprisingly, there is little direct experimental evidence for either of these. In this study, we examined both explanations using the pipevine swallowtail butterfly, Battus philenor L. If sodium increases neuromuscular activity, males consuming sodium should be better fliers than males without sodium. If males collect sodium for nuptial gifts that benefit their mates, males consuming sodium may have greater mating success than males without sodium. In that case, females then need an honest cue/signal of the quality of male-provided direct benefits that they can assess before mating. If sodium affects male courtship flight by increasing neuromuscular activity, how a male courts could serve as such a premating cue/signal of male benefit quality. Therefore, sodium may benefit males in terms of obtaining mates by increasing their neuromuscular activity. In this study we found that males that consumed sodium courted more vigorously and had greater mating success than males that consumed water. In addition, the courtship displays of males consuming sodium were significantly different from those of males consuming water, providing a possible honest cue/signal of male benefit quality that females can assess. Interestingly, we did not find evidence that sodium consumption affects male flight outside of courtship. That only aspects of male flight related to mating were affected by sodium, while aspects of general flight were not, is consistent with the idea that sodium may benefit males in terms of obtaining mates via effects on neuromuscular activity. PMID:27103748

  3. Genotyping and investigating capsular polysaccharide synthesis gene loci of non-serotypeable Streptococcus suis isolated from diseased pigs in Canada.

    PubMed

    Zheng, Han; Qiu, Xiaotong; Roy, David; Segura, Mariela; Du, Pengchen; Xu, Jianguo; Gottschalk, Marcelo

    2017-02-20

    Streptococcus suis (S. suis) is an important swine pathogen and an emerging zoonotic agent. Most clinical S. suis strains express capsular polysaccharides (CPS), which can be typed by antisera using the coagglutination test. In this study, 79 S. suis strains recovered from diseased pigs in Canada and which could not be typed using antisera were further characterized by capsular gene typing and sequencing. Four patterns of cps locus were observed: (1) fifteen strains were grouped into previously reported serotypes but presented several mutations in their cps loci, when compared to available data from reference strains; (2) seven strains presented a complete deletion of the cps locus, which would result in an inability to synthesize capsule; (3) forty-seven strains were classified in recently described novel cps loci (NCLs); and (4) ten strains carried novel NCLs not previously described. Different virulence gene profiles (based on the presence of mrp, epf, and/or sly) were observed in these non-serotypeable strains. This study provides further insight in understanding the genetic characteristics of cps loci in non-serotypeable S. suis strains recovered from diseased animals. When using a combination of the previously described 35 serotypes and the complete NCL system, the number of untypeable strains recovered from diseased animals in Canada would be significantly reduced.

  4. CHS5, a gene involved in chitin synthesis and mating in Saccharomyces cerevisiae.

    PubMed Central

    Santos, B; Duran, A; Valdivieso, M H

    1997-01-01

    The CHS5 locus of Saccharomyces cerevisiae is important for wild-type levels of chitin synthase III activity. chs5 cells have reduced levels of this activity. To further understand the role of CHS5 in yeast, the CHS5 gene was cloned by complementation of the Calcofluor resistance phenotype of a chs5 mutant. Transformation of the mutant with a plasmid carrying CHS5 restored Calcofluor sensitivity, wild-type cell wall chitin levels, and chitin synthase III activity levels. DNA sequence analysis reveals that CHS5 encodes a unique polypeptide of 671 amino acids with a molecular mass of 73,642 Da. The predicted sequence shows a heptapeptide repeated 10 times, a carboxy-terminal lysine-rich tail, and some similarity to neurofilament proteins. The effects of deletion of CHS5 indicate that it is not essential for yeast cell growth; however, it is important for mating. Deletion of CHS3, the presumptive structural gene for chitin synthase III activity, results in a modest decrease in mating efficiency, whereas chs5delta cells exhibit a much stronger mating defect. However, chs5 cells produce more chitin than chs3 mutants, indicating that CHS5 plays a role in other processes besides chitin synthesis. Analysis of mating mixtures of chs5 cells reveals that cells agglutinate and make contact but fail to undergo cell fusion. The chs5 mating defect can be partially rescued by FUS1 and/or FUS2, two genes which have been implicated previously in cell fusion, but not by FUS3. In addition, mating efficiency is much lower in fus1 fus2 x chs5 than in fus1 fus2 x wild type crosses. Our results indicate that Chs5p plays an important role in the cell fusion step of mating. PMID:9111317

  5. No evidence for MHC class I-based disassortative mating in a wild population of great tits.

    PubMed

    Sepil, I; Radersma, R; Santure, A W; De Cauwer, I; Slate, J; Sheldon, B C

    2015-03-01

    Genes of the major histocompatibility complex (MHC) are regarded as a potentially important target of mate choice due to the fitness benefits that may be conferred to the offspring. According to the complementary genes hypothesis, females mate with MHC dissimilar males to enhance the immunocompetence of their offspring or to avoid inbreeding depression. Here, we investigate whether selection favours a preference for maximally dissimilar or optimally dissimilar MHC class I types, based on MHC genotypes, average amino acid distances and the functional properties of the antigen-binding sites (MHC supertypes); and whether MHC type dissimilarity predicts relatedness between mates in a wild great tit population. In particular, we explore the role that MHC class I plays in female mate choice decisions while controlling for relatedness and spatial population structure, and examine the reproductive fitness consequences of MHC compatibility between mates. We find no evidence for the hypotheses that females select mates on the basis of either maximal or optimal MHC class I dissimilarity. A weak correlation between MHC supertype sharing and relatedness suggests that MHC dissimilarity at functional variants may not provide an effective index of relatedness. Moreover, the reproductive success of pairs did not vary with MHC dissimilarity. Our results provide no support for the suggestion that selection favours, or that mate choice realizes, a preference for complimentary MHC types.

  6. Capsular Switching and Other Large-Scale Recombination Events in Invasive Sequence Type 1 Group B Streptococcus

    PubMed Central

    Neemuchwala, Alefiya; Teatero, Sarah; Athey, Taryn B.T.; McGeer, Allison

    2016-01-01

    We report several cases of recombination events leading to capsular switching among sequence type (ST) 1 group B Streptococcus strains. These strains otherwise shared a common genome backbone with serotype V ST1 strains. However, the genomes of ST1 serotype V strains and those of serotypes VI, VII, and VIII strains differed substantially. PMID:27767925

  7. Enteropathogenic Escherichia coli Serotypes and Endemic Diarrhea in Infants

    PubMed Central

    Toledo, M. Regina F.; Alvariza, M. do Carmo B.; Murahovschi, Jayme; Ramos, Sonia R. T. S.; Trabulsi, Luiz R.

    1983-01-01

    Enteropathogenic Escherichia coli serotypes were searched for in feces of 550 children with endemic diarrhea and in 129 controls, in São Paulo, in 1978 and 1979; serotypes O111ab:H−, O111ab:H2, and O119:H6 were significantly associated with diarrhea in children 0 to 5 months old and were the most frequent agents of diarrhea in this age group as compared with enterotoxigenic and enteroinvasive E. coli, Salmonella sp., Shigella sp., and Yersinia enterocolitica. It is concluded that various enteropathogenic E. coli serotypes may be agents of endemic infantile diarrhea. PMID:6339384

  8. Mating unplugged: a model for the evolution of mating plug (dis-)placement.

    PubMed

    Fromhage, Lutz

    2012-01-01

    Mating plugs are male-derived structures that may impede female remating by physically obstructing the female genital tract. Although mating plugs exist in many taxa, the forces shaping their evolution are poorly understood. A male can clearly benefit if his mating plug secures his paternity. It is unclear, however, how plug efficacy can be maintained over evolutionary time in the face of counteracting selection on males' ability to remove any plugs placed by their rivals. Here, I present a game-theory model and a simulation model to address this problem. The models predict that evolutionarily stable levels of mating-plug efficacy should be high when (1) the number of mating attempts per female is low; (2) the sex ratio is male-biased, and (3) males are sperm-limited. I discuss these results in the light of empirical data.

  9. Trends in Serotype Distribution and Antimicrobial Susceptibility in Salmonella enterica Isolates from Humans in Belgium, 2009 to 2013

    PubMed Central

    Ceyssens, Pieter-Jan; Mattheus, Wesley; Vanhoof, Raymond

    2014-01-01

    The Belgian National Reference Centre for Salmonella received 16,544 human isolates of Salmonella enterica between January 2009 and December 2013. Although 377 different serotypes were identified, the landscape is dominated by S. enterica serovars Typhimurium (55%) and Enteritidis (19%) in a ratio which is inverse to European Union averages. With outbreaks of Salmonella serotypes Ohio, Stanley, and Paratyphi B variant Java as prime examples, 20 serotypes displayed significant fluctuations in this 5-year period. Typhoid strains account for 1.2% of Belgian salmonellosis cases. Large-scale antibiotic susceptibility analyses (n = 4,561; panel of 12 antibiotics) showed declining resistance levels in S. Enteritis and Typhimurium isolates for 8 and 3 tested agents, respectively. Despite low overall resistance to ciprofloxacin (4.4%) and cefotaxime (1.6%), we identified clonal lineages of Salmonella serotypes Kentucky and Infantis displaying rising resistance against these clinically important drugs. Quinolone resistance is mainly mediated by serotype-specific mutations in GyrA residues Ser83 and Asp87 (92.2% not wild type), while an additional ParC_Ser80Ile mutation leads to ciprofloxacin resistance in 95.5% S. Kentucky isolates, which exceeds European averages. Plasmid-mediated quinolone resistance (PMQR) alleles qnrA1 (n = 1), qnrS (n = 9), qnrD1 (n = 4), and qnrB (n = 4) were found in only 3.0% of 533 isolates resistant to nalidixic acid. In cefotaxime-resistant isolates, we identified a broad range of Ambler class A and C β-lactamase genes (e.g., blaSHV-12, blaTEM-52, blaCTX-M-14, and blaCTX-M-15) commonly associated with members of the family Enterobacteriaceae. In conclusion, resistance to fluoroquinolones and cefotaxime remains rare in human S. enterica, but clonal resistant serotypes arise, and continued (inter)national surveillance is mandatory to understand the origin and routes of dissemination thereof. PMID:25385108

  10. Chimpanzees breed with genetically dissimilar mates

    PubMed Central

    Rudicell, Rebecca S.; Li, Yingying; Hahn, Beatrice H.; Wroblewski, Emily; Pusey, Anne E.

    2017-01-01

    Inbreeding adversely affects fitness, whereas heterozygosity often augments it. Therefore, mechanisms to avoid inbreeding and increase genetic distance between mates should be advantageous in species where adult relatives reside together. Here we investigate mate choice for genetic dissimilarity in chimpanzees, a species in which many females avoid inbreeding through dispersal, but where promiscuous mating and sexual coercion can limit choice when related adults reside together. We take advantage of incomplete female dispersal in Gombe National Park, Tanzania to compare mate choice for genetic dissimilarity among immigrant and natal females in two communities using pairwise relatedness measures in 135 genotyped chimpanzees. As expected, natal females were more related to adult males in their community than were immigrant females. However, among 62 breeding events, natal females were not more related to the sires of their offspring than immigrant females, despite four instances of close inbreeding. Moreover, females were generally less related to the sires of their offspring than to non-sires. These results demonstrate that chimpanzees may be capable of detecting relatedness and selecting mates on the basis of genetic distance. PMID:28280546

  11. HOW MATE AVAILABILITY INFLUENCES FILIAL CANNIBALISM.

    PubMed

    Deal, Nicholas D S; Wong, Bob B M

    2016-03-01

    Parents sometimes eat their young to reduce the consequences of brood overcrowding, for nutritional gain, and/or to redirect investment toward future reproduction. It has been predicted that filial cannibalism should be more prevalent when mate availability is high as parents can more easily replace consumed young. Reviewing the available evidence--which comes almost exclusively from studies of paternal caring fish--we find support in some species, but not others. To explain this, we hypothesize that sexual selection against filial cannibalism and/or the tendency to acquire larger broods under conditions of high mate availability discourages filial cannibalism. Additionally, filial cannibalism might occur when mate availability is low to facilitate survival until access to mates improves. Since attractiveness can also influence remating opportunities, we review its effect on filial cannibalism, finding that attractive parents engage in less filial cannibalism. More research is needed to determine if this relationship is a result of individuals showing adaptive plasticity in filial cannibalism based on self-perceived attractiveness, or if the attractiveness of individuals is reduced by their propensity to commit filial cannibalism. More generally, to advance our understanding of how mate availability influences filial cannibalism, future studies should also focus on a wider range of taxa.

  12. In vitro antifungal susceptibility profiles and genotypes of 308 clinical and environmental isolates of Cryptococcus neoformans var. grubii and Cryptococcus gattii serotype B from north-western India.

    PubMed

    Chowdhary, Anuradha; Randhawa, Harbans Singh; Sundar, Gandhi; Kathuria, Shallu; Prakash, Anupam; Khan, Ziauddin; Sun, Sheng; Xu, Jianping

    2011-07-01

    Cryptococcus neoformans and Cryptococcus gattii are aetiological agents of cryptococcosis, a major opportunistic systemic mycosis of increasing global importance. This study reports the antifungal susceptibility profiles of clinical and environmental isolates of C. neoformans var. grubii, genotype VNI/AFLP1 (n = 246), and C. gattii serotype B, genotype VGI/AFLP4 (n = 62), originating from patients and environmental sources in north-western India. All of the C. neoformans var. grubii and C. gattii isolates were mating type α. Using the broth microdilution method, both species were found to be susceptible to the antifungals tested except for two clinical C. neoformans var. grubii isolates that were resistant to 5-flucytosine (MIC >64 µg ml⁻¹). Data on the geometric mean of MICs revealed that C. gattii was significantly less susceptible than C. neoformans var. grubii to fluconazole, itraconazole and voriconazole (P<0.0001). In addition, the MIC₉₀ of C. gattii was twofold higher than that of C. neoformans var. grubii for fluconazole, itraconazole and voriconazole. However, no statistically significant difference in susceptibility of the two Cryptococcus species was observed against amphotericin B and 5-flucytosine. Furthermore, the environmental C. neoformans var. grubii isolates were significantly less susceptible to fluconazole, itraconazole and 5-flucytosine (P<0.0001) than the clinical isolates. A continued surveillance of antifungal susceptibility of clinical and environmental strains of C. neoformans and C. gattii is desirable to monitor the emergence of any resistant strains in order to ensure more successful therapy of cryptococcosis.

  13. Mate sampling and choosiness in the sand goby

    PubMed Central

    Lindström, Kai; Lehtonen, Topi K.

    2013-01-01

    To date, mate choice studies have mostly focused on establishing which mates are chosen or how the choices are performed. Here, we combined these two approaches by empirically testing how latency to mate is affected by various search costs, variation in mate quality and female quality in the sand goby (Pomatoschistus minutus). Our results show that females adjust their mating behaviour according to the costs and benefits of the choice situation. Specifically, they mated sooner when access to males was delayed and when the presence of other females presented a mate sampling cost. We also found a positive link between size variation among potential mating partners and spawning delay in some (but not all) experimental conditions. By contrast, we did not find the number of available males or the females' own body size (‘quality’) to affect mating latency. Finally, female mating behaviour varied significantly between years. These findings are notable for demonstrating that (i) mate sampling time is particularly sensitive to costs and, to a lesser degree, to variation among mate candidates, (ii) females' mating behaviour is sensitive to qualitative rather than to quantitative variation in their environment, and (iii) a snapshot view may describe mate sampling behaviour unreliably. PMID:23804620

  14. The small regulatory RNA FasX enhances group A Streptococcus virulence and inhibits pilus expression via serotype-specific targets.

    PubMed

    Danger, Jessica L; Cao, Tram N; Cao, Tran H; Sarkar, Poulomee; Treviño, Jeanette; Pflughoeft, Kathryn J; Sumby, Paul

    2015-04-01

    Bacterial pathogens commonly show intra-species variation in virulence factor expression and often this correlates with pathogenic potential. The group A Streptococcus (GAS) produces a small regulatory RNA (sRNA), FasX, which regulates the expression of pili and the thrombolytic agent streptokinase. As GAS serotypes are polymorphic regarding (a) FasX abundance, (b) the fibronectin, collagen, T-antigen (FCT) region of the genome, which contains the pilus genes (nine different FCT-types), and (c) the streptokinase-encoding gene (ska) sequence (two different alleles), we sought to test whether FasX regulates pilus and streptokinase expression in a serotype-specific manner. Parental, fasX mutant and complemented derivatives of serotype M1 (ska-2, FCT-2), M2 (ska-1, FCT-6), M6 (ska-2, FCT-1) and M28 (ska-1, FCT-4) isolates were compared. While FasX reduced pilus expression in each serotype, the molecular basis differed, as FasX bound, and inhibited the translation of, different FCT-region mRNAs. FasX enhanced streptokinase expression in each serotype, although the degree of regulation varied. Finally, we established that the regulation afforded by FasX enhances GAS virulence, assessed by a model of bacteremia using human plasminogen-expressing mice. Our data are the first to identify and characterize serotype-specific regulation by an sRNA in GAS, and to show an sRNA directly contributes to GAS virulence.

  15. Draft Genome Sequences of Clinical Isolates of Serotype 6E Streptococcus pneumoniae from Five Asian Countries

    PubMed Central

    Park, In Ho; Baek, Jin Yang; Song, Jae-Hoon

    2017-01-01

    ABSTRACT Although serotype 6E Streptococcus pneumoniae consistently expresses capsules of either vaccine-serotype 6A or 6B, certain genetic variants of serotype 6E may evade vaccine induced immunity. Thus, draft genome sequences from five clinical isolates of serotype 6E from each of five different Asian countries have been generated to provide insight into the genomic diversity in serotype 6E strains. PMID:28280026

  16. Rearing Temperature Influences Adult Response to Changes in Mating Status.

    PubMed

    Westerman, Erica; Monteiro, Antónia

    2016-01-01

    Rearing environment can have an impact on adult behavior, but it is less clear how rearing environment influences adult behavior plasticity. Here we explore the effect of rearing temperature on adult mating behavior plasticity in the butterfly Bicyclus anynana, a species that has evolved two seasonal forms in response to seasonal changes in temperature. These seasonal forms differ in both morphology and behavior. Females are the choosy sex in cohorts reared at warm temperatures (WS butterflies), and males are the choosy sex in cohorts reared at cooler temperatures (DS butterflies). Rearing temperature also influences mating benefits and costs. In DS butterflies, mated females live longer than virgin females, and mated males live shorter than virgin males. No such benefits or costs to mating are present in WS butterflies. Given that choosiness and mating costs are rearing temperature dependent in B. anynana, we hypothesized that temperature may also impact male and female incentives to remate in the event that benefits and costs of second matings are similar to those of first matings. We first examined whether lifespan was affected by number of matings. We found that two matings did not significantly increase lifespan for either WS or DS butterflies relative to single matings. However, both sexes of WS but not DS butterflies experienced decreased longevity when mated to a non-virgin relative to a virgin. We next observed pairs of WS and DS butterflies and documented changes in mating behavior in response to changes in the mating status of their partner. WS but not DS butterflies changed their mating behavior in response to the mating status of their partner. These results suggest that rearing temperature influences adult mating behavior plasticity in B. anynana. This developmentally controlled behavioral plasticity may be adaptive, as lifespan depends on the partner's mating status in one seasonal form, but not in the other.

  17. Rearing Temperature Influences Adult Response to Changes in Mating Status

    PubMed Central

    Westerman, Erica; Monteiro, Antónia

    2016-01-01

    Rearing environment can have an impact on adult behavior, but it is less clear how rearing environment influences adult behavior plasticity. Here we explore the effect of rearing temperature on adult mating behavior plasticity in the butterfly Bicyclus anynana, a species that has evolved two seasonal forms in response to seasonal changes in temperature. These seasonal forms differ in both morphology and behavior. Females are the choosy sex in cohorts reared at warm temperatures (WS butterflies), and males are the choosy sex in cohorts reared at cooler temperatures (DS butterflies). Rearing temperature also influences mating benefits and costs. In DS butterflies, mated females live longer than virgin females, and mated males live shorter than virgin males. No such benefits or costs to mating are present in WS butterflies. Given that choosiness and mating costs are rearing temperature dependent in B. anynana, we hypothesized that temperature may also impact male and female incentives to remate in the event that benefits and costs of second matings are similar to those of first matings. We first examined whether lifespan was affected by number of matings. We found that two matings did not significantly increase lifespan for either WS or DS butterflies relative to single matings. However, both sexes of WS but not DS butterflies experienced decreased longevity when mated to a non-virgin relative to a virgin. We next observed pairs of WS and DS butterflies and documented changes in mating behavior in response to changes in the mating status of their partner. WS but not DS butterflies changed their mating behavior in response to the mating status of their partner. These results suggest that rearing temperature influences adult mating behavior plasticity in B. anynana. This developmentally controlled behavioral plasticity may be adaptive, as lifespan depends on the partner’s mating status in one seasonal form, but not in the other. PMID:26863319

  18. Patterns of Nonrandom Mating Within and Across 11 Major Psychiatric Disorders

    PubMed Central

    Nordsletten, Ashley E.; Larsson, Henrik; Crowley, James J.; Almqvist, Catarina; Lichtenstein, Paul; Mataix-Cols, David

    2016-01-01

    IMPORTANCE Psychiatric disorders are heritable, polygenic traits, which often share risk alleles and for which nonrandom mating has been suggested. However, despite the potential etiological implications, the scale of nonrandom mating within and across major psychiatric conditions remains unclear. OBJECTIVE To quantify the nature and extent of nonrandom mating within and across a broad range of psychiatric conditions at the population level. DESIGN, SETTING, AND PARTICIPANTS Population-based cohort using Swedish population registers. Participants were all Swedish residents with a psychiatric diagnosis of interest (attention-deficit/hyperactivity disorder, autism spectrum disorder, schizophrenia, bipolar disorder, major depression, generalized anxiety disorder, agoraphobia, social phobia, obsessive-compulsive disorder, anorexia, or substance abuse), along with their mates. Individuals with select nonpsychiatric disorders (Crohn’s disease, type 1 and type 2 diabetes mellitus, multiple sclerosis, or rheumatoid arthritis) were included for comparison. General population samples were also derived and matched 1:5 with each case proband. Inpatient and outpatient diagnostic data were derived from the Swedish National Patient Register (1973-2009), with analyses conducted between June 2014 and May 2015. MAIN OUTCOMES AND MEASURES Correlation in the diagnostic status of mates both within and across disorders. Conditional logistic regression was used to quantify the odds of each diagnosis in the mates of cases relative to matched population controls. RESULTS Across cohorts, data corresponded to 707 263 unique case individuals, with women constituting 45.7% of the full population. Positive correlations in diagnostic status were evident between mates. Within-disorder correlations were marginally higher (range, 0.11-0.48) than cross-disorder correlations (range, 0.01-0.42). Relative to matched populations, the odds of psychiatric case probands having an affected mate were

  19. Visual mate choice in poison frogs.

    PubMed Central

    Summers, K; Symula, R; Clough, M; Cronin, T

    1999-01-01

    We investigated female mate choice on the basis of visual cues in two populations of Dendrobates pumilio, the strawberry poison frog, from the Bocas del Toro Archipelago in Panama, Central America. Mate choice experiments were carried out by presenting subject females of each of two morphs of this species (orange and green) from two different island populations (Nancy Key and Pope Island) with object frogs (one of each morph) under glass at one end of a terrarium. Recorded calls were played simultaneously from behind both object frogs. The experiments were carried out under two light regimes: (i) white light, and (ii) relatively monochromatic filtered blue light. Subject females from each population displayed a significant preference for their own morph under white light, but not under blue light. These results indicate that female D. pumilio use visual cues in mate choice, and suggest that colour may be the visual cue they use. PMID:10649631

  20. Social wasps are a Saccharomyces mating nest.

    PubMed

    Stefanini, Irene; Dapporto, Leonardo; Berná, Luisa; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

    2016-02-23

    The reproductive ecology of Saccharomyces cerevisiae is still largely unknown. Recent evidence of interspecific hybridization, high levels of strain heterozygosity, and prion transmission suggest that outbreeding occurs frequently in yeasts. Nevertheless, the place where yeasts mate and recombine in the wild has not been identified. We found that the intestine of social wasps hosts highly outbred S. cerevisiae strains as well as a rare S. cerevisiae×S. paradoxus hybrid. We show that the intestine of Polistes dominula social wasps favors the mating of S. cerevisiae strains among themselves and with S. paradoxus cells by providing a succession of environmental conditions prompting cell sporulation and spores germination. In addition, we prove that heterospecific mating is the only option for European S. paradoxus strains to survive in the gut. Taken together, these findings unveil the best hidden secret of yeast ecology, introducing the insect gut as an environmental alcove in which crosses occur, maintaining and generating the diversity of the ascomycetes.

  1. Social wasps are a Saccharomyces mating nest

    PubMed Central

    Stefanini, Irene; Dapporto, Leonardo; Berná, Luisa; Polsinelli, Mario; Turillazzi, Stefano; Cavalieri, Duccio

    2016-01-01

    The reproductive ecology of Saccharomyces cerevisiae is still largely unknown. Recent evidence of interspecific hybridization, high levels of strain heterozygosity, and prion transmission suggest that outbreeding occurs frequently in yeasts. Nevertheless, the place where yeasts mate and recombine in the wild has not been identified. We found that the intestine of social wasps hosts highly outbred S. cerevisiae strains as well as a rare S. cerevisiae×S. paradoxus hybrid. We show that the intestine of Polistes dominula social wasps favors the mating of S. cerevisiae strains among themselves and with S. paradoxus cells by providing a succession of environmental conditions prompting cell sporulation and spores germination. In addition, we prove that heterospecific mating is the only option for European S. paradoxus strains to survive in the gut. Taken together, these findings unveil the best hidden secret of yeast ecology, introducing the insect gut as an environmental alcove in which crosses occur, maintaining and generating the diversity of the ascomycetes. PMID:26787874

  2. [Serotypes and antimicrobial susceptibilities of invasive group A streptococci identified in eastern Black Sea region of Turkey].

    PubMed

    Bayramoğlu, Gülçin; Topkaya, Aynur E; Balıkcı, Ahmet; Aydın, Faruk

    2011-07-01

    Frequency of invasive group A streptococcus (GAS) infections is increasing worldwide in recent 20 years. Serotypes responsible for these clinical manifestations and their antibiotic susceptibilities should be known in order to establish preventive measures and initiate appropriate treatment. This study was aimed to determine the serotypes, antibiotic susceptibilities and inducible clindamycin resistance among invasive GAS isolated between 2006-2009 period. A total of 22 GAS strains isolated from clinical samples [sterile body fluids (peritoneal, pleural, pericardial, joint and cerebrospinal fluids), blood, tissue biopsy] of the patients (14 male, 8 female; age range: 3-82 years, median age: 59) who admitted to Karadeniz Technical University Faculty of Medicine, Farabi Hospital located in Trabzon province (Eastern Black Sea Region of Turkey), between March 2006 and March 2009 were included in the study. GAS serotypes were determined by the investigation of serum opacity factors (SOF), T proteins and M proteins. SOF production was investigated by microplate method using human serum and SOF types were determined by SOF-inhibition test using specific antisera. T protein types were detected by agglutination method using polyvalent anti-T sera, and M serotypes were detected by capillary precipitation method using M antisera. Antimicrobial susceptibility tests were performed by disk-diffusion method according to CLSI recommendations. SOF were positive in 9 (41%) samples. Use of T antiserum yielded T (n= 8) and U (n= 7) types and M antiserum M1 (n= 4) and M2 (n= 3) types. The overall antibiotic susceptibility rate of the isolates was 68% (15/22) and overall resistance rate was 32% (7/22). All of the GAS strains were found susceptible to benzylpenicillin, ceftriaxone, vancomycin, levofloxacine and linezolid, however 9 (41%) were intermediate susceptible to tetracycline and 1 (4.5%) was intermediate susceptible to erythromycin. Four (18%) strains were found resistant to

  3. [The prevalence of different Streptococcus pneumoniaе serotypes in the children presenting with ENT infections or carrying nasopharyngeal pathogens].

    PubMed

    Boronina, L G; Samatova, E V; Druĭ, A E; Panina, E Iu; Kochneva, N A; Vodovoz, N Iu; Murunova, N V; Gruzdev, A I; Lakhno, T I

    2013-01-01

    The objective of the present study was to elucidate the etiopathological significance of various Streptococcus pneumoniae serotypes in the children presenting with ENT infections and carrying nasopharyngeal pathogens. The incidence of the latter condition was 19.5% in the children free from S. pneumoniae infection in comparison with 20.9% and 30.7% in those having diagnosis of otitis media and rhinosinusitis respectively. Fifty five (88.8%) of the 62 isolated streptococcal strains were grouped into types with the use of multiplex PCR. Twelve serotypes were identified in the patients presenting with rhinosinusitis with the predominance of 6A/6B and 3 (40.5%) compared with seven isolated from the carriers of nasopharyngeal pathogens. In this group, type 3 also prevailed (26.5%) whereas other serotypes occurred less frequently: 23F (13,4%), indivisible totality of 8, 9V, 9A, 1F, 11A, 211B, 11C, 11D, 12F, 15A, and 33F (13.4%), 20 (6.7%), 19A (6.7%), 14 (6.7%), 6A,6B (6.7%). The serotypes of S. pneumoniae isolated from the patients with rhinosinusitis were found to show 55.3% identity with those present in the composition of the conjugated 7-valent pneumococcal vaccines, 63.2% identity with the 10-valent vaccine, 81.6% identity with the 11p-valnet vaccine, and 84.2% identity with the 13-valent vaccine.

  4. Identification and characterization of a DNA region involved in the export of capsular polysaccharide by Actinobacillus pleuropneumoniae serotype 5a.

    PubMed Central

    Ward, C K; Inzana, T J

    1997-01-01

    Actinobacillus pleuropneumoniae synthesizes a serotype-specific capsular polysaccharide that acts as a protective barrier to phagocytosis and complement-mediated killing. To begin understanding the role of A. pleuropneumoniae capsule in virulence, we sought to identify the genes involved in capsular polysaccharide export and biosynthesis. A 5.3-kb XbaI fragment of A. pleuropneumoniae serotype 5a J45 genomic DNA that hybridized with DNA probes specific for the Haemophilus influenzae type b cap export region was cloned and sequenced. This A. pleuropneumoniae DNA fragment encoded four open reading frames, designated cpxDCBA. The nucleotide and predicted amino acid sequences of cpxDCBA contained a high degree of homology to the capsule export genes of H. influenzae type b bexDCBA, Neisseria meningitidis group B ctrABCD, and, to a lesser extent, Escherichia coli K1 and K5 kpsE and kpsMT. When present in trans, the cpxDCBA gene cluster complemented kpsM::TnphoA or kpsT::TnphoA mutations, determined by enzyme immunoassay and by restored sensitivity to a K5-specific bacteriophage. A cpxCB probe hybridized to genomic DNA from all A. pleuropneumoniae serotypes tested, indicating that this DNA was conserved among serotypes. These data suggest that A. pleuropneumoniae produces a group II family capsule similar to those of related mucosal pathogens. PMID:9169799

  5. Practical Prediction of Ten Common Streptococcus pneumoniae Serotypes/Serogroups in One PCR Reaction by Multiplex Ligation-Dependent Probe Amplification and Melting Curve (MLPA-MC) Assay in Shenzhen, China

    PubMed Central

    Zheng, Lei; Zou, Jianhua; Jin, Ping; Hu, Yanwei; Kudinha, Timothy; Kong, Fanrong; Chen, Xu; Wang, Qian

    2015-01-01

    Background Streptococcus pneumoniae has more than 95 distinct serotypes described to date. However, only certain serotypes are more likely to cause pneumococcal diseases. Thus serotype surveillance is important for vaccine formula design as well as in post-vaccine serotype shift monitor. The goal of this study was to develop a practical screening assay for ten Shenzhen China common pneumococcal serotypes/serogroups in one molecular reaction. Methods A molecular assay, based on multiplex ligation-dependent probe amplification (MLPA) and melting curve (MC) analysis, was developed in an integrated approach (MLPA-MC) for the detection of ten capsular serotypes/serogroups 4, 6 (6A/6B/6C/6D), 9V/9A, 14, 15F/15A, 15B/15C, 18 (18F/18A/18B/18C), 19F, 19A and 23F. We designed serotype/serogroup-specific MLPA probes and fluorescent detection probes to discriminate the different serotypes/serogroups in one molecular reaction. The three steps of MLPA-MC assay are continuous reactions in one well detected by LightCycler 480. A total of 210 S. pneumoniae isolates from our local Maternity and Child Health Hospital were randomly chosen to evaluate the assay against published multiplex PCR assays. Results Our results showed that 198 (94.3%) of S. pneumoniae isolates were type-able by our assays and the results were in complete concordance with the published multiplex PCRs. Using the MLPA-MC assay, 96 S. pneumoniae isolates could be typed within 3 hours with limited hands-on time. This serotype/serogroup-screening assay can be easily modified or extended by modification of the serotype/serogroup-specific MLPA probes combinations according to the needs of different laboratories. Conclusions We recommend use of this assay as a starting point for screening serotype/serogroup frequencies. There is a need for this assay to be combined with other molecular typing assays, like published serotype specific PCRs, or even the Quellung reaction for serotype confirmation. PMID:26151828

  6. Epitope Addition and Ablation via Manipulation of a Dengue Virus Serotype 1 Infectious Clone

    PubMed Central

    Gallichotte, Emily N.; Menachery, Vineet D.; Yount, Boyd L.; Widman, Douglas G.; Dinnon, Kenneth H.; Hartman, Steven; de Silva, Aravinda M.

    2017-01-01

    ABSTRACT Despite the clinical relevance, dengue virus (DENV) research has been hampered by the absence of robust reverse genetic systems to manipulate the viral serotypes for propagation and generation of mutant viruses. In this article, we describe application of an infectious clone system for DENV serotype 1 (DENV1). Similar to previous clones in both flaviviruses and coronaviruses, the approach constructs a panel of contiguous cDNAs that span the DENV genome and can be systematically and directionally assembled to produce viable, full-length viruses. Comparison of the virus derived from the infectious clone with the original viral isolate reveals identical sequence, comparable endpoint titers, and similar focus staining. Both focus-forming assays and percent infection by flow cytometry revealed overlapping replication levels in two different cell types. Moreover, serotype-specific monoclonal antibodies (MAbs) bound similarly to infectious clone and the natural isolate. Using the clone, we were able to insert a DENV4 type-specific epitope recognized by primate MAb 5H2 into envelope (E) protein domain I (EDI) of DENV1 and recover a viable chimeric recombinant virus. The recombinant DENV1 virus was recognized and neutralized by the DENV4 type-specific 5H2 MAb. The introduction of the 5H2 epitope ablated two epitopes on DENV1 EDI recognized by human MAbs (1F4 and 14C10) that strongly neutralize DENV1. Together, the work demonstrates the utility of the infectious clone and provides a resource to rapidly manipulate the DENV1 serotype for generation of recombinant and mutant viruses. IMPORTANCE Dengue viruses (DENVs) are significant mosquito-transmitted pathogens that cause widespread infection and can lead to severe infection and complications. Here we further characterize a novel and robust DENV serotype 1 (DENV1) infectious clone system that can be used to support basic and applied research. We demonstrate how the system can be used to probe the antigenic

  7. Genomic Analysis of a Serotype 5 Streptococcus pneumoniae Outbreak in British Columbia, Canada, 2005–2009

    PubMed Central

    Miller, Ruth R.; Langille, Morgan G. I.; Montoya, Vincent; Crisan, Anamaria; Stefanovic, Aleksandra; Martin, Irene; Patrick, David M.; Romney, Marc; Tyrrell, Gregory; Jones, Steven J. M.; Brinkman, Fiona S. L.; Tang, Patrick

    2016-01-01

    Background. Streptococcus pneumoniae can cause a wide spectrum of disease, including invasive pneumococcal disease (IPD). From 2005 to 2009 an outbreak of IPD occurred in Western Canada, caused by a S. pneumoniae strain with multilocus sequence type (MLST) 289 and serotype 5. We sought to investigate the incidence of IPD due to this S. pneumoniae strain and to characterize the outbreak in British Columbia using whole-genome sequencing. Methods. IPD was defined according to Public Health Agency of Canada guidelines. Two isolates representing the beginning and end of the outbreak were whole-genome sequenced. The sequences were analyzed for single nucleotide variants (SNVs) and putative genomic islands. Results. The peak of the outbreak in British Columbia was in 2006, when 57% of invasive S. pneumoniae isolates were serotype 5. Comparison of two whole-genome sequenced strains showed only 10 SNVs between them. A 15.5 kb genomic island was identified in outbreak strains, allowing the design of a PCR assay to track the spread of the outbreak strain. Discussion. We show that the serotype 5 MLST 289 strain contains a distinguishing genomic island, which remained genetically consistent over time. Whole-genome sequencing holds great promise for real-time characterization of outbreaks in the future and may allow responses tailored to characteristics identified in the genome. PMID:27366170

  8. Antimicrobial susceptibilities and serotypes of invasive Streptococcus pneumoniae strains in Switzerland.

    PubMed Central

    Wüst, J; Huf, E; Kayser, F H

    1995-01-01

    In 1993 and 1994, 10 microbiological laboratori