Proposal of Mingxiaea gen. nov. for the anamorphic basidiomycetous yeast species in the Bulleribasidium clade (Tremellales) based on molecular phylogenetic analysis and description of four novel Mingxiaea species.

Int J Syst Evol Microbiol. 2010 Feb 5;

Authors: Wang QM, Bai FY, Fungsin B, Boekhout T, Nakase T

The distinction and monophyletic property of the basidiomycetous yeast species in the Bulleribasidium clade of the Tremellales was resolved by molecular phylogenetic analysis based on the combined sequences of the 18S rRNA gene, internal transcribed spacer (ITS) region including 5.8S rRNA gene and 26S rRNA gene D1/D2 domain. The addition of more new anamorphic species identified from the ballistoconidium-forming yeasts isolated from China to the clade confirmed and strengthened the separation of this clades from other clades or lineages in the Tremellales. A new anamorphic genus Mingxiaea gen. nov. (type species: Mingxiaea variabilis comb. nov.) is therefore proposed to accommodate the anamorphic species in the Bulleribasidium clade. Six new combinations are proposed for the described species of this clade which were formerly assigned to the genus Bullera. Four new species in the new genus were identified from 16 ballistoconidium-forming yeast strains isolated from plant leaves collected in Hainan province, southern China by D1/D2 and ITS sequence analyses. The new species are described as Mingxiaea sanyaensis (type strain AS 2. 3623T = CBS 11408T), Mingxiaea hainanensis (type strain AS 2.4161T = CBS 11409T), Mingxiaea foliicola (type strain AS 2.3518T = CBS 11407T) and Mingxiaea wuzhishanensis (type strain AS 2.4163T = CBS 11411T).

PMID: 20139282 [PubMed - as supplied by publisher]

Related Articles

Subversion of innate immune responses by Brucella through the targeted degradation of the TLR signaling adapter, MAL.

J Immunol. 2010 Jan 15;184(2):956-64

Authors: Sengupta D, Koblansky A, Gaines J, Brown T, West AP, Zhang D, Nishikawa T, Park SG, Roop RM, Ghosh S

Gram-negative bacteria belonging to the Brucella species cause chronic infections that can result in undulant fever, arthritis, and osteomyelitis in humans. Remarkably, Brucella sp. genomes encode a protein, named TcpB, that bears significant homology with mammalian Toll/IL-1 receptor domains and whose expression causes degradation of the phosphorylated, signal competent form of the adapter MyD88-adapter-like (MAL). This effect of TcpB is mediated through its box 1 region and has no effect on other TLR adapter proteins such as MyD88 or TIR-domain containing adapter protein-inducing IFNbeta. TcpB also does not affect a mutant, signal-incompetent form of MAL that cannot be phosphorylated. Interestingly, the presence of TcpB leads to enhanced polyubiquitination of MAL, which is likely responsible for its accelerated degradation. A Brucella abortus mutant lacking TcpB fails to reduce levels of MAL in infected macrophages. Therefore, TcpB represents a unique pathogen-derived molecule that suppresses host innate-immune responses by specifically targeting an individual adapter molecule in the TLR signaling pathway for degradation.

PMID: 20018612 [PubMed - indexed for MEDLINE]

Neoriojatrema mokokchungensis n. g., n. sp. (Monogenea: Polystomatidae: Polystomatinae) from the urinary bladder of a megophryid frog, Xenophrys glandulosa, in Nagaland, north-eastern India.

J Helminthol. 2010 Feb 8;:1-6

Authors: Imkongwapang R, Tandon V

A new monogenean fluke, collected from the urinary bladder of a megophryid frog, Xenophrys glandulosa Fei, Ye & Huang, 1991 from Mokokchung and Tuensang districts of Nagaland, north-eastern India is described. Of the six genera under the subfamily Polystomatinae (Polystomatidae) known so far, the present form comes closer to Eupolystoma Kaw, 1950; Pseudopolystoma Yamaguti, 1963 and Riojatrema Lamothe-Argumedo, 1964, in all of which the opisthaptor lacks large hooks. However, a combination of characters, namely, shape of the body, rounded or bulbous pharynx, intestinal caeca not joining posteriorly in the opisthaptoral region, ovary located in the anterior third of the body and presence of vaginal apertures, sets the present form apart from all these genera, and also from the known species of Riojatrema. These differences warrant the establishment of a new species and a new genus to accommodate the present form. The validity of this new monogenean, named as Neoriojatrema mokokchungensis after the type locality of the fluke, is discussed.

PMID: 20137104 [PubMed - as supplied by publisher]

Molecular analysis of bacterial population structure and dynamics during cold storage of untreated and treated milk.

Int J Food Microbiol. 2010 Jan 20;

Authors: Rasolofo EA, St-Gelais D, Lapointe G, Roy D

Spoilage bacteria in milk are controlled by treatments such as thermization, microfiltration and addition of carbon dioxide. However, little information is known about the changes in microbial communities during subsequent cold storage of treated milk. Culture-dependent methods and a direct molecular approach combining 16S rRNA gene clone libraries and quantitative PCR (Q-PCR) were applied to obtain a better overview of the structure and the dynamics of milk microbiota. Raw milk samples were treated by the addition of carbon dioxide (CO(2)), thermization (TH) or microfiltration (MF) and stored at 4 degrees C or 8 degrees C up to 7d. Untreated milk (UT) was used as a control. Psychrotrophic and staphylococci bacteria were enumerated in the milk samples by culture methods. For the molecular approach, DNA was extracted from milk samples and 16S rRNA gene was amplified by PCR with universal primers prior to cloning. The Q-PCR method was used to evaluate the dynamics of dominant bacterial species revealed by clone library analysis of 16S rRNA gene. Comparison of the 16S rRNA gene sequence indicated that the two most abundant operational taxonomic units (OTU), determined at 97% identity, belonged to the class Gammaproteobacteria (40.3% of the 1415 sequences) and Bacilli (40%). Dominant bacterial species in UT, CO(2) and TH milk samples at day 3 were affiliated with Staphylococcus, Streptococcus, Clostridia, Aerococcus, Facklamia, Corynebacterium, Acinetobacter and Trichococcus. Dominant bacterial species detected in MF milk were Stenotrophomonas, Pseudomonas and Delftia, while Pseudomonas species dominated the bacterial population of UT, CO(2) and MF milk samples at day 7. Staphylococcus and Delftia were the dominant bacterial species in thermized milk. Q-PCR results showed that populations of S. aureus, A. viridans, A. calcoaceticus, C. variabile and S. uberis were stable during 7d of storage at 4 degrees C. Populations of P. fluorescens, S. uberis and total bacteria increased in UT and CO(2) milk samples during 7d of storage at 8 degrees C and were noticeable from day 3. This study shows new microbial species which can develop during cold storage after milk treatment and contributes to identifying causes of reduced shelf life and deterioration of technological properties of milk during storage.

PMID: 20137820 [PubMed - as supplied by publisher]

Phylogeny of Hammerhead Sharks (Family Sphyrnidae) Inferred from Mitochondrial and Nuclear Genes.

Mol Phylogenet Evol. 2010 Feb 3;

Authors: Lim DD, Motta P, Mara K, Martin AP

Hammerhead sharks (Family Sphyrnidae) get their name from their laterally expanded, dorsal-ventrally compressed head, a structure referred to as the cephalofoil. Species within the family vary for head size and shape and for body size in ways that are functionally significant. Here we infer the phylogeny for all species within the family based on analysis of mitochondrial and nuclear genes amounting to 6292 base pairs. Mixed model Bayesian analysis of the concatenated data and Bayesian estimation of the species tree (BEST) converged on the same topology of the relationships. Shimodaira-Hasegawa tests revealed that all previously proposed hypotheses could be refuted by the data. The new hypothesis for the group suggests that the ancestor of all extant sharks was large (> 200 cms) and that small body size probably evolved twice at different times and places. Moreover, the results suggest that once the cephalofoil evolved, it underwent divergent evolution in different lineages presumably in response to unique selective regimes.

PMID: 20138218 [PubMed - as supplied by publisher]

Phylogenetic relationships and divergence dates of the whole mitochondrial genome sequences among three gibbon genera.

Mol Phylogenet Evol. 2010 Feb 3;

Authors: Matsudaira K, Ishida T

Phylogenetic relationships of gibbons (4 genera, 12 species) deduced from short/partial mitochondrial DNA sequences were with low resolution and inconsistent. Their divergence over the short period of time may require longer sequences for the higher resolution. To solve the problems, we newly sequenced the whole mitochondrial genome of Hylobates agilis, Hylobates pileatus, Nomascus sp. and Symphalangus syndactylus. A highly resolved phylogenetic tree was obtained for the mitochondrial genome in the neighbor-joining, maximum-parsimony and maximum-likelihood analyses. The divergence dates of mitochondrial genome were estimated by Bayesian method; Nomascus and the other two genera to 8.0 million years ago (MYA), Symphalangus and Hylobates to 7.0 MYA, Hylobates pileatus and the other two Hylobates species to 3.9 MYA and Hylobates lar and Hylobates agilis to 3.3 MYA. Our results support the generic rank of Nomascus, Symphalangus and Hylobates, and proposed a new scenario that the Hylobates gibbons diverged in the Pliocene. This study shows the potential of the whole mitochondrial genome analyses to reveal detailed divergence history of gibbons.

PMID: 20138221 [PubMed - as supplied by publisher]

Supermatrix and Species Tree Methods Resolve Phylogenetic Relationships Within the Big Cats, Panthera (Carnivora: Felidae).

Mol Phylogenet Evol. 2010 Feb 3;

Authors: Davis BW, Li G, Murphy WJ

The pantherine lineage of cats diverged from the remainder of modern Felidae less than 11 million years ago and consists of the five big cats of the genus Panthera, the lion, tiger, jaguar, leopard, and snow leopard, as well as the closely related clouded leopard. A significant problem exists with respect to the precise phylogeny of these highly threatened great cats. Despite multiple publications on the subject, no two molecular studies have reconstructed Panthera with the same topology. These evolutionary relationships remain unresolved partially due to the recent and rapid radiation of pantherines in the Pliocene, individual speciation events occurring within less than 1 million years, and probable introgression between lineages following their divergence. We provide an alternative, highly supported interpretation of the evolutionary history of the pantherine lineage using novel and published DNA sequence data from the autosomes, both sex chromosomes and the mitochondrial genome. New sequences were generated for 39 single-copy regions of the felid Y chromosome, as well as four mitochondrial and four autosomal gene segments, totaling 28.7 kb. Phylogenetic analysis of these new data, combined with all published data in GenBank, highlighted the prevalence of phylogenetic disparities stemming either from the amplification of a mitochondrial to nuclear translocation event (numt), or errors in species identification. Our 47.6 kb combined dataset was analyzed as a supermatrix and with respect to individual partitions using maximum likelihood and Bayesian phylogenetic inference, in conjunction with Bayesian estimation of species trees (BEST) which accounts for heterogeneous gene histories. Our results yield a robust consensus topology supporting the monophyly of lion and leopard, with jaguar sister to these species, as well as a sister species relationship of tiger and snow leopard. These results highlight new avenues for the study of speciation genomics and understanding the historical events surrounding the origin of the members of this lineage.

PMID: 20138224 [PubMed - as supplied by publisher]

Bacterial Enteritis as a Risk Factor for Childhood Intussusception: A Retrospective Cohort Study.

J Pediatr. 2010 Feb 4;

Authors: Nylund CM, Denson LA, Noel JM

OBJECTIVE: To assess the relationship between bacterial enteritis and intussusception. STUDY DESIGN: The Patient Administration Systems and Biostatistics Activity database from January 2002 to December 2005 was examined for clinic visits or hospital admission to a Department of Defense medical facility for children age 0-5 years. The study included the International Statistical Classification of Diseases and Related Health Problems diagnosis-related group (DRG) codes for infections with Yersinia enterocolitica, Escherichia coli, Shigella species, Salmonella species, and Campylobacter. Identified patients were then assessed for the intussusception DRG code for 0-180 days postinfection. The total number of children enrolled in military treatment facilities in the same age group (denominator) was obtained. RESULTS: Bacterial enteritis significantly increased the relative risk of intussusception. An increased risk was found following infection with Salmonella, E coli, Shigella, and Campylobacter. The relative risk for intussusception following any bacterial enteritis was 40.6 (95% confidence interval = 28.6-57.5; P < .0001). CONCLUSIONS: Bacterial enteritis is a significant risk factor for the subsequent development of intussusception in children.

PMID: 20138300 [PubMed - as supplied by publisher]

Female genital morphology and mating behavior of Orchestina (Arachnida: Araneae: Oonopidae).

Zoology (Jena). 2010 Feb 5;

Authors: Burger M, Izquierdo M, Carrera P

The unusual reproductive biology of many spider species makes them compelling targets for evolutionary investigations. Mating behavior studies combined with genital morphological investigations help to understand complex spider reproductive systems and explain their function in the context of sexual selection. Oonopidae are a diverse spider family comprising a variety of species with complex internal female genitalia. Data on oonopid phylogeny are preliminary and especially studies on their mating behavior are very rare. The present investigation reports on the copulatory behavior of an Orchestina species for the first time. The female genitalia are described by means of serial semi-thin sections and scanning electron microscopy. Females of Orchestina sp. mate with multiple males. On average, copulations last between 15.4 and 23.54min. During copulation, the spiders are in a position taken by most theraphosids and certain members of the subfamily Oonopinae: the male pushes the female back and is situated under her facing the female's sternum. Males of Orchestina sp. possibly display post-copulatory mate-guarding behavior. The female genitalia are complex. The genital opening leads into the uterus externus from which a single receptaculum emerges. The dorsal wall of the receptaculum forms a sclerite serving as muscle attachment. A sclerotized plate with attached muscles lies in the posterior wall of the uterus externus. The plate might be used to lock the uterus during copulation. The present study gives no direct evidence for cryptic female choice in Orchestina sp. but suggests that sexual selection occurs in the form of sperm competition through sperm mixing.

PMID: 20138745 [PubMed - as supplied by publisher]

Shimoni bat virus, a new representative of the Lyssavirus genus.

Virus Res. 2010 Feb 4;

Authors: Kuzmin IV, Mayer AE, Niezgoda M, Markotter W, Agwanda B, Breiman RF, Rupprecht CE

During 2009, 616 bats representing at least 22 species were collected from 10 locations throughout Kenya. A new lyssavirus, named Shimoni bat virus (SHIBV), was isolated from the brain of a dead Commerson's leaf-nosed bat (Hipposideros commersoni), found in a cave in the coastal region of Kenya. Genetic distances and phylogenetic reconstructions, implemented for each gene and for the concatenated alignment of all five structural genes (N, P, M, G and L), demonstrated that SHIBV cannot be identified with any of the existing species, but rather should be considered an independent species within phylogroup II of the Lyssavirus genus, most similar to Lagos bat virus (LBV). Antigenic reaction patterns with anti-nucleocapsid monoclonal antibodies corroborated these distinctions. In addition, new data on the diversity of LBV suggests that this species may be subdivided quantitatively into three separate genotypes. However, the identity values alone are not considered sufficient criteria for demarcation of new species within LBV.

PMID: 20138934 [PubMed - as supplied by publisher]

Molecular cloning, expression and antioxidant activity of a peroxiredoxin 2 homologue from Lampetra japonica.

Fish Shellfish Immunol. 2010 Feb 4;

Authors: Sun J, Liu X, Li Q

Peroxiredoxin (Prx) is a cellular antioxidant protein family that plays important roles in oxidative stress and immune cytotoxicity. In this study, we cloned a homologue of the Prx2 from the buccal gland of Lampetra japonica (L. japonica). L. japonica Prx2 (Lj-Prx2) contained two highly conserved motifs and shared more than 70% identity with the homologs from other vertebrate species. Phylogenetic analysis revealed that Lj-Prx2 is closely related to other available teleost Prx2. The real-time PCR results demonstrated that the Prx2 gene was widely expressed in adult lamprey. In addition, the expression of Prx2 gene was particularly up-regulated in red blood cells (RBCs) after the experimental animals were challenged with lipopolysaccharide (LPS) in vivo. Lj-Prx2 gene was subcloned into the pET23b vector and expressed in Escherichia coli BL21 (DE3). The recombinant L. japonica Prx2 (rLj-Prx2) was purified by using His Bind affinity chromatography. Polyclonal antibody to rLj-Prx2 was generated in New Zealand Rabbit. Western blot analysis showed that the Lj-Prx2 is present in the buccal gland secretion, suggesting the secretory feature of it. The function assays revealed that rLj-Prx2 has the capability to reduce the H(2)O(2) when dithiothreitol (DTT) is used as a reducing equivalent and to protect DNA from oxidative damage. These findings suggested that Lj-Prx2 probably plays an essential role in antioxidant defense in RBCs to keep lamprey alive.

PMID: 20139002 [PubMed - as supplied by publisher]

Molecular phylogeny and historical biogeography of Nacella (Patellogastropoda: Nacellidae) in the Southern Ocean.

Mol Phylogenet Evol. 2010 Feb 4;

Authors: Gonz�lez-Wevar CA, Nakano T, Ca�ete JI, Poulin E

The evolution and the historical biogeography of the Southern Ocean marine benthic fauna are closely related to major tectonic and climatic changes that occurred in this region during the last 55 million years (Ma). Several families, genera and even species of marine organisms are shared between distant biogeographic provinces in this region. This pattern of distribution in marine benthic invertebrates has been commonly explained by vicariant speciation due to plate tectonics. However, recent molecular studies have provided new evidence for long-distance dispersion as a plausible explanation of biogeographical patterns in the Southern Ocean. True limpets of the genus Nacella are currently distributed in different biogeographic regions of the Southern Ocean such as Antarctica, Kerguelen Province, southern New Zealand Antipodean Province, North-Central Chile and South American Magellanic Province. Here, we present phylogenetic reconstructions using two mitochondrial DNA markers (Cytochrome Oxidase I and Cytochrome b) to look into the relationships among Nacella species and to determine the origin and diversification of the genus. Phylogenies were reconstructed using two methods, Maximum Parsimony and Bayesian Inference, while divergence time among Nacella species was estimated following a relaxed Bayesian approach. For this purpose, we collected inter- and subtidal species belonging to four biogeographic regions in the Southern Ocean: Antarctica, Kerguelen Province, Central Chile, and Magellanic Province. Our molecular results agree with previous morphological and molecular studies supporting the monophyly of Nacella and its sister relationship with Cellana. Two rounds of diversification are recognized in the evolution of Nacella. The first one occurred at the end of the Miocene and gave rise to the main lineages, currently distributed in Antarctica, South America or Kerguelen Province. Large genetic divergence was detected among Nacella species from these distant biogeographic provinces emphasizing the significance of trans-oceanic discontinuities and suggesting long-distance dispersal was relatively unimportant. The second diversification round consisted of a more recent Pleistocene radiation in the Magellanic region. In this province, different morphological species of Nacella exhibit extreme low levels of genetic divergence with absence of reciprocal monophyly among them. According to our time estimation, the origin and diversification of Nacella in the Southern Ocean is more recent (<15 MY) than the expected under the hypothesis of vicariant speciation due to plate tectonics. The evolution of this genus seems to be closely related to drastic climatic and oceanographic changes in the Southern Ocean during the middle Miocene Climatic Transition. In spite of the high number of species described for the Magellanic Province, molecular results indicate that these species are the most derived ones in the evolution of the genus and therefore that the Magellanic region does not need to correspond to the origin center of Nacella. The absence of genetic divergence among these species supports a very recent radiation process accompanied by rapid morphological and ecological diversification.

PMID: 20139020 [PubMed - as supplied by publisher]

Scardovia wiggsiae sp. nov., isolated from the human oral cavity and clinical material.

Int J Syst Evol Microbiol. 2010 Feb 5;

Authors: Downes J, Mantzourani M, Beighton D, Hooper S, Wilson MJ, Nicholson A, Wade WG

Six strains of anaerobic, pleomorphic Gram-positive bacilli isolated from the human oral cavity and an infected arm wound were subjected to a comprehensive range of phenotypic and genotypic tests and were found to comprise a homogeneous group. 16S rRNA gene sequence analysis revealed the strains to constitute a novel group within the genus Scardovia, most closely related to Scardovia inopinata, the type species of the genus. A new species, Scardovia wiggsiae sp. nov. is proposed to accommodate these strains. Scardovia wiggsiae is saccharolytic and produces acetic and lactic acids as end products of fermentation. The principal cellular long chain fatty acids are C16:0 and C18:1omega9c. Polar lipid analysis revealed a variety of glycolipids detected together with diphosphatidylglycerol, an unidentified phospholipid and an unidentified phosphoglycolipid. No respiratory quinones were detected. The peptidoglycan is of the type A4alpha L-Lys-Thr-Glu, with L-Lys partially replaced by L-Orn. The G + C content of the DNA of the type strain of Scardovia wiggsiae is 55 mol %. The type strain of Scardovia wiggsiae is C1A_55T (DSM 22547T =CCUG 58090T).

PMID: 20139283 [PubMed - as supplied by publisher]

Advanced identification of proteins in uncharacterized proteomes by pulsed in vivo SILAC.

Mol Cell Proteomics. 2010 Feb 5;

Authors: Looso M, Borchardt T, Krueger M, Braun T

Despite progress in the characterization of their genomes, proteomes of several model organisms are often only poorly characterized. This problem is aggravated by the presence of large numbers of EST clones that lack homologues in other species, which makes it difficult to identify new proteins irrespective of whether such molecules are involved in species-specific biological processes or not. We have used a pulsed SILAC-based mass spectrometry method, which is based on the detection of paired peptides after 13C6-lysine incorporation into proteins in vivo, to greatly increase the confidence of protein identification in cross-species database searches. The method was applied to identify nearly 3000 proteins in regenerating tails of the urodele amphibian Notophthalmus viridescens, which possesses outstanding capabilities in the regeneration of complex tissues. We reason that pulsed in vivo SILAC represents a versatile tool to identify new proteins in species for which only limited sequence information exists.

PMID: 20139370 [PubMed - as supplied by publisher]

Harnessing Listeria monocytogenes to target tumors.

Cancer Biol Ther. 2010 Feb 17;9(4)

Authors: Gravekamp C, Paterson Y

Because of its cytosolic localization, Listeria monocytogenes (LM) has long been considered an attractive tool for delivering tumor-associated antigens (TAA) antigens in vivo to combat cancer. LM directly infects antigen-presenting cells (APC) such as monocytes, macrophages and dendritic cells (DC), thereby delivering the TAA into their cytoplasm, resulting in processing and presentation of the antigen to the immune system. This activates adaptive and innate immune responses to the TAA, mediating tumor cell cytolysis. Recently we discovered additional pathways by which Listeria can be harnessed to induce tumor cell death, which suggest new directions in the development of vaccines or therapies against cancer. In one approach, we have used Listeria to induce immune responses that destroy tumor vasculature. Another new pathway involves selective infection of cancer cells with Listeria, followed by tumor cell death through the production of high levels of reactive oxygen species (ROS) and through Listeria-specific cytotoxic T lymphocytes (CTL). This review will focus on the most recent studies on the multiple pathways of LM and how they can be harnessed in the battle against cancer.

PMID: 20139702 [PubMed - as supplied by publisher]

Helping in food-deceptive orchids?: A possible new mechanism maintaining polymorphism of floral signals.

Plant Signal Behav. 2010 May 17;5(5)

Authors: Dormont L, Delle-Vedove R, Bessi�re JM, Hossaert-Mc Key M, Schatz B

Why different color morphs have evolved in flowering plants, and how they are maintained in populations, have long intrigued ecologists. The impact of variation in floral color and odor (the two are frequently associated) on reproductive success remains poorly understood. In European rewardless orchids, many species occasionally show rare white-flowered individuals within populations of the common-colored morph. In a recent study, we found that in Orchis mascula the presence of rare white-flowered morphs significantly increased the reproductive success (from 6% to 27%) of purple-flowered plants, while success of the white morph remained low. This surprising result appears due solely to floral color polymorphism, which in this species is not associated with odor polymorphism. We hypothesize that color variation plays the key role in pollinator attraction, and that white-flowered individuals may be regarded to function as "sensory traps". We also propose that the maintenance of white-flowered mutants in O. mascula may result through kin selection, in which they act as helpers increasing the reproductive success of related purple individuals.

PMID: 20139736 [PubMed - as supplied by publisher]

Reverse Genetics in Candida albicans Predicts ARF Cycling Is Essential for Drug Resistance and Virulence.

PLoS Pathog. 2010;6(2):e1000753

Authors: Epp E, Vanier G, Harcus D, Lee AY, Jansen G, Hallett M, Sheppard DC, Thomas DY, Munro CA, Mullick A, Whiteway M

Candida albicans, the major fungal pathogen of humans, causes life-threatening infections in immunocompromised individuals. Due to limited available therapy options, this can frequently lead to therapy failure and emergence of drug resistance. To improve current treatment strategies, we have combined comprehensive chemical-genomic screening in Saccharomyces cerevisiae and validation in C. albicans with the goal of identifying compounds that can couple with the fungistatic drug fluconazole to make it fungicidal. Among the genes identified in the yeast screen, we found that only AGE3, which codes for an ADP-ribosylation factor GTPase activating effector protein, abrogates fluconazole tolerance in C. albicans. The age3 mutant was more sensitive to other sterols and cell wall inhibitors, including caspofungin. The deletion of AGE3 in drug resistant clinical isolates and in constitutively active calcineurin signaling mutants restored fluconazole sensitivity. We confirmed chemically the AGE3-dependent drug sensitivity by showing a potent fungicidal synergy between fluconazole and brefeldin A (an inhibitor of the guanine nucleotide exchange factor for ADP ribosylation factors) in wild type C. albicans as well as in drug resistant clinical isolates. Addition of calcineurin inhibitors to the fluconazole/brefeldin A combination only initially improved pathogen killing. Brefeldin A synergized with different drugs in non-albicans Candida species as well as Aspergillus fumigatus. Microarray studies showed that core transcriptional responses to two different drug classes are not significantly altered in age3 mutants. The therapeutic potential of inhibiting ARF activities was demonstrated by in vivo studies that showed age3 mutants are avirulent in wild type mice, attenuated in virulence in immunocompromised mice and that fluconazole treatment was significantly more efficacious when ARF signaling was genetically compromised. This work describes a new, widely conserved, broad-spectrum mechanism involved in fungal drug resistance and virulence and offers a potential route for single or improved combination therapies.

PMID: 20140196 [PubMed - as supplied by publisher]

Differential Patterns of Infection and Disease with P. falciparum and P. vivax in Young Papua New Guinean Children.

PLoS One. 2010;5(2):e9047

Authors: Lin E, Kiniboro B, Gray L, Dobbie S, Robinson L, Laumaea A, Sch�pflin S, Stanisic D, Betuela I, Blood-Zikursh M, Siba P, Felger I, Schofield L, Zimmerman P, Mueller I

BACKGROUND: Where P. vivax and P. falciparum occur in the same population, the peak burden of P. vivax infection and illness is often concentrated in younger age groups. Experiences from malaria therapy patients indicate that immunity is acquired faster to P. vivax than to P. falciparum challenge. There is however little prospective data on the comparative risk of infection and disease from both species in young children living in co-endemic areas. METHODOLOGY/PRINCIPAL FINDINGS: A cohort of 264 Papua New Guinean children aged 1-3 years (at enrolment) were actively followed-up for Plasmodium infection and febrile illness for 16 months. Infection status was determined by light microscopy and PCR every 8 weeks and at each febrile episode. A generalised estimating equation (GEE) approach was used to analyse both prevalence of infection and incidence of clinical episodes. A more pronounced rise in prevalence of P. falciparum compared to P. vivax infection was evident with increasing age. Although the overall incidence of clinical episodes was comparable (P. falciparum: 2.56, P. vivax 2.46 episodes / child / yr), P. falciparum and P. vivax infectious episodes showed strong but opposing age trends: P. falciparum incidence increased until the age of 30 months with little change thereafter, but incidence of P. vivax decreased significantly with age throughout the entire age range. For P. falciparum, both prevalence and incidence of P. falciparum showed marked seasonality, whereas only P. vivax incidence but not prevalence decreased in the dry season. CONCLUSIONS/SIGNIFICANCE: Under high, perennial exposure, children in PNG begin acquiring significant clinical immunity, characterized by an increasing ability to control parasite densities below the pyrogenic threshold to P. vivax, but not to P. falciparum, in the 2(nd) and 3(rd) year of life. The ability to relapse from long-lasting liver-stages restricts the seasonal variation in prevalence of P. vivax infections.

PMID: 20140220 [PubMed - as supplied by publisher]

Cloning, expression and characterisation of an HtrA-like serine protease produced in vivo by Mycobacterium leprae.

Mem Inst Oswaldo Cruz. 2009 Dec;104(8):1132-8

Authors: Ribeiro-Guimar�es ML, Marengo EB, Tempone AJ, Amaral JJ, Klitzke CF, Silveira EK, Portaro FC, Pessolani MC

Members of the high temperature requirement A (HtrA) family of chaperone proteases have been shown to play a role in bacterial pathogenesis. In a recent report, we demonstrated that the gene ML0176, which codes for a predicted HtrA-like protease, a gene conserved in other species of mycobacteria, is transcribed by Mycobacterium leprae in human leprosy lesions. In the present study, the recombinant ML0176 protein was produced and its enzymatic properties investigated. M. lepraerecombinant ML0176 was able to hydrolyse a variety of synthetic and natural peptides. Similar to other HtrA proteins, this enzyme displayed maximum proteolytic activity at temperatures above 40 degrees C and was completely inactivated by aprotinin, a protease inhibitor with high selectivity for serine proteases. Finally, analysis of M. leprae ML0176 specificity suggested a broader cleavage preference than that of previously described HtrAs homologues. In summary, we have identified an HtrA-like protease in M. lepraethat may constitute a potential new target for the development of novel prophylactic and/or therapeutic strategies against mycobacterial infections.

PMID: 20140374 [PubMed - in process]

[Experimental model in rats for the development of pseudoarthrosis.]

Rev Col Bras Cir. 2009 Dec;36(6):514-8

Authors: Ferreira ML, Silva PC, Pereira Lde P, Franco RS, Mello NB, Amaral AC, Schanaider A

OBJECTIVE: We sought to describe a new model of pseudoarthrosis in rats free of pathogenic species (Rattus norvegicus albinus - SPF). METHODS: The animals were randomly distributed into two groups were used: Group 1 - Control (n =6); Group 2 - Experimental (n =6). In the Control group an access to the femur followed by the synthesis of the muscular and skin layers was done. The Experimental group was submitted to osteotomy of the femur and a pedicle flap of the fascia lata was interposed between the segments resulting from the surgically induced fracture. The procedure was carried on with both alignment and approximation of the fractured bone through the use of mononylon thread introduced into holes created in the proximal and distal. RESULTS: Radiological and anatomopathological studies showed the absence of bone consolidation with persistence of fibro-osteoid tissue up to 120 days of follow-up. CONCLUSION: The experimental model is suitable for the development of a pseudoarthrosis in rats.

PMID: 20140396 [PubMed - in process]

Maitake beta-glucan promotes recovery of leukocytes and myeloid cell function in peripheral blood from paclitaxel hematotoxicity.

Cancer Immunol Immunother. 2010 Feb 6;

Authors: Lin H, de Stanchina E, Zhou XK, Hong F, Seidman A, Fornier M, Xiao WL, Kennelly EJ, Wesa K, Cassileth BR, Cunningham-Rundles S

Bone marrow myelotoxicity is a major limitation of chemotherapy. While granulocyte colony stimulating factor (G-CSF) treatment is effective, alternative approaches to support hematopoietic recovery are sought. We previously found that a beta-glucan extract from maitake mushroom Grifola frondosa (MBG) enhanced colony forming unit-granulocyte monocyte (CFU-GM) activity of mouse bone marrow and human hematopoietic progenitor cells (HPC), stimulated G-CSF production and spared HPC from doxorubicin toxicity in vitro. This investigation assessed the effects of MBG on leukocyte recovery and granulocyte/monocyte function in vivo after dose intensive paclitaxel (Ptx) in a normal mouse. After a cumulative dose of Ptx (90-120 mg/kg) given to B6D2F1mice, daily oral MBG (4 or 6 mg/kg), intravenous G-CSF (80 microg/kg) or Ptx alone were compared for effects on the dynamics of leukocyte recovery in blood, CFU-GM activity in bone marrow and spleen, and granulocyte/monocyte production of reactive oxygen species (ROS). Leukocyte counts declined less in Ptx + MBG mice compared to Ptx-alone (p = 0.024) or Ptx + G-CSF treatment (p = 0.031). Lymphocyte levels were higher after Ptx + MBG but not Ptx + G-CSF treatment compared to Ptx alone (p < 0.01). MBG increased CFU-GM activity in bone marrow and spleen (p < 0.001, p = 0.002) 2 days after Ptx. After two additional days (Ptx post-day 4), MBG restored granulocyte/monocyte ROS response to normal levels compared to Ptx-alone and increased ROS response compared to Ptx-alone or Ptx + G-CSF (p < 0.01, both). The studies indicate that oral MBG promoted maturation of HPC to become functionally active myeloid cells and enhanced peripheral blood leukocyte recovery after chemotoxic bone marrow injury.

PMID: 20140432 [PubMed - as supplied by publisher]

Streptococcus ursoris sp. nov., isolated from oral cavities of bears.

Int J Syst Evol Microbiol. 2010 Feb 5;

Authors: Shinozaki-Kuwahara N, Takada K, Hirasawa M

Three Gram-positive, catalase-negative; coccus-shaped organisms were isolated from the oral cavities of bears. The isolates were tentatively identified as a streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed that the organisms are members of the genus Streptococcus, but they did not correspond to any previously identified species of the genus Streptococcus. The nearest phylogenetic relatives of the isolates were Streptococcus ratti (98.6%), however, DNA-DNA hybridization analysis showed that the isolates displayed less than 15% relatedness with the type strain of S. ratti. The colonies of these strains were grown on Mitis Salivarius agar and showed an extracellular polysaccharide-producing colony morphology. Based on phenotypic and phylogenetic evidence, it is proposed that these isolates be classified in the genus Streptococcus, as Streptococcus ursoris sp. nov. The type strain of S. ursoris is NUM 1615T (=JCM 16361T, =DSM 22768T).

PMID: 20139281 [PubMed - as supplied by publisher]

Larkinella bovis sp. nov., isolated from fermented bovine products and emended descriptions of the genus Larkinella and of Larkinella insperata Vancanneyt et al. 2006.

Int J Syst Evol Microbiol. 2010 Feb 5;

Authors: Anandham R, Kwon SW, Weon HY, Kim SJ, Kim YS, Gandhi PI, Kim YK, Jee HJ

A bacterial strain designated M2T2B15T was isolated from fermented bovine products and characterized using a polyphasic approach. Colonies were reddish-pink in colour and circular with entire margins. Cells were strictly aerobic, Gram-reaction-negative, oxidase and catalase positive rods devoid of flagellum and motile by gliding. Flexirubin-type pigments were absent. 16S rRNA gene sequence analysis indicated that strain M2T2B15T showed 94.4% sequence similarity with Larkinella insperata LMG 22510T. No other recognized species showed >87% 16S rRNA gene sequence similarity to strain M2T2B15T. The major cellular fatty acids were C16:1omega5c, C15:0 iso and C17:0 iso 3-OH. The polar lipids consisted of phosphatidylethanolamine, phosphatidylserine, two unidentified aminophospholipids and two unidentified polar lipids. Menaquinone 7 (MK-7) was the major respiratory quinone. The G+C content of the DNA was 52 mol%. Results of phenotypic, and genotypic data and phylogenetic inference clearly indicate that strain M2T2B15T represents a novel species within the genus Larkinella for which the name Larkinella bovis sp. nov. is proposed. The type strain is M2T2B15T (KACC 14040T= NBRC 106324T). Further, emended descriptions of the genus Larkinella and of Larkinella insperata LMG 22510T Vancanneyt et al. 2006 are also proposed.

PMID: 20139284 [PubMed - as supplied by publisher]