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Aeromonas piscicola sp. nov., isolated from diseased fish.
Syst Appl Microbiol. 2009 Jun 29;
Authors: Beaz-Hidalgo R, Alperi A, Figueras MJ, Romalde JL
Four Aeromonas strains (S1.2(T), EO-0505, TC1 and TI 1.1) isolated from moribund fish in Spain showed a restriction fragment length polymorphism (RFLP) pattern related to strains of Aeromonas salmonicida and Aeromonas bestiarum but their specific taxonomic position was unclear. Multilocus sequence analysis (MLSA) of housekeeping genes rpoD, gyrB, recA and dnaJ confirmed the allocation of these isolates to an unknown genetic lineage within the genus Aeromonas with A. salmonicida, A. bestiarum and Aeromonas popoffii as the phylogenetically nearest neighbours. Furthermore, a strain biochemically labelled as Aeromonas hydrophila (AH-3), showing a pattern of A. bestiarum based on 16S rDNA-RFLP, also clustered with the unknown genetic lineage. The genes rpoD and gyrB proved to be the best phylogenetic markers for differentiating these isolates from their neighbouring species. Useful phenotypic features for differentiating the novel species from other known Aeromonas species included their ability to hydrolyze elastin, produce acid from l-arabinose and salicin, and their inability to produce acid from lactose and use l-lactate as a sole carbon source. A polyphasic approach using phenotypic characterization, phylogenetic analysis of the 16S rRNA gene and of four housekeeping genes, as well as DNA-DNA hybridization studies and an analysis of the protein profiles by MALDI-TOF-MS, showed that these strains represented a novel species for which the name Aeromonas piscicola sp. nov. is proposed with isolate S1.2(T) (=CECT 7443(T), =LMG 24783(T)) as the type strain.
PMID: 19570633 [PubMed - as supplied by publisher]
A new primate from the Eocene Pondaung Formation of Myanmar and the monophyly of Burmese amphipithecids.
Proc Biol Sci. 2009 Jul 1;
Authors: Beard KC, Marivaux L, Chaimanee Y, Jaeger JJ, Marandat B, Tafforeau P, Soe AN, Tun ST, Kyaw AA
The family Amphipithecidae is one of the two fossil primate taxa from Asia that appear to be early members of the anthropoid clade. Ganlea megacanina, gen. et sp. nov., is a new amphipithecid from the late middle Eocene Pondaung Formation of central Myanmar. The holotype of Ganlea is distinctive in having a relatively enormous lower canine showing heavy apical wear, indicating an important functional role of the lower canine in food preparation and ingestion. A phylogenetic analysis of amphipithecid relationships suggests that Ganlea is the sister taxon of Myanmarpithecus, a relatively small-bodied taxon that has often, but not always, been included in Amphipithecidae. Pondaungia is the sister taxon of the Ganlea + Myanmarpithecus clade. All three Pondaung amphipithecid genera are monophyletic with respect to Siamopithecus, which is the most basal amphipithecid currently known. The inclusion of Myanmarpithecus in Amphipithecidae diminishes the likelihood that amphipithecids are specially related to adapiform primates. Extremely heavy apical wear has been documented on the lower canines of all three genera of Burmese amphipithecids. This distinctive wear pattern suggests that Burmese amphipithecids were an endemic radiation of hard object feeders that may have been ecological analogues of living New World pitheciin monkeys.
PMID: 19570790 [PubMed - as supplied by publisher]
Trypanosoma irwini n. sp (Sarcomastigophora: Trypanosomatidae) from the koala ( Phascolarctos cinereus).
Parasitology. 2009 Jul;136(8):875-85
Authors: McInnes LM, Gillett A, Ryan UM, Austen J, Campbell RS, Hanger J, Reid SA
The morphology and genetic characterization of a new species of trypanosome infecting koalas (Phascolarctos cinereus) are described. Morphological analysis of bloodstream forms and phylogenetic analysis at the 18S rDNA and gGAPDH loci demonstrated this trypanosome species to be genetically distinct and most similar to Trypanosoma bennetti, an avian trypanosome with a genetic distance of 0.9% at the 18S rDNA and 10.7% at the gGAPDH locus. The trypanosome was detected by 18S rDNA PCR in the blood samples of 26 out of 68 (38.2%) koalas studied. The aetiological role of trypanosomes in koala disease is currently poorly defined, although infection with these parasites has been associated with severe clinical signs in a number of koalas. Based on biological and genetic characterization data, this trypanosome species infecting koalas is proposed to be a new species Trypanosome irwini n. sp.
PMID: 19570316 [PubMed - in process]
Seasonal source-sink dynamics at the edge of a species' range.
Ecology. 2009 Jun;90(6):1574-85
Authors: Kanda LL, Fuller TK, Sievert PR, Kellogg RL
The roles of dispersal and population dynamics in determining species' range boundaries recently have received theoretical attention but little empirical work. Here we provide data on survival, reproduction, and movement for a Virginia opossum (Didelphis virginiana) population at a local distributional edge in central Massachusetts (USA). Most juvenile females that apparently exploited anthropogenic resources survived their first winter, whereas those using adjacent natural resources died of starvation. In spring, adult females recolonized natural areas. A life-table model suggests that a population exploiting anthropogenic resources may grow, acting as source to a geographically interlaced sink of opossums using only natural resources, and also providing emigrants for further range expansion to new human-dominated landscapes. In a geographical model, this source-sink dynamic is consistent with the local distribution identified through road-kill surveys. The Virginia opossum's exploitation of human resources likely ameliorates energetically restrictive winters and may explain both their local distribution and their northward expansion in unsuitable natural climatic regimes. Landscape heterogeneity, such as created by urbanization, may result in source-sink dynamics at highly localized scales. Differential fitness and individual dispersal movements within local populations are key to generating regional distributions, and thus species ranges, that exceed expectations.
PMID: 19569372 [PubMed - in process]
The intertwined population biology of two Amazonian myrmecophytes and their symbiotic ants.
Ecology. 2009 Jun;90(6):1595-607
Authors: Frederickson ME, Gordon DM
A major question in ecology is: how do mutualisms between species affect population dynamics? For four years, we monitored populations of two Amazonian myrmecophytes, Cordia nodosa and Duroia hirsuta, and their symbiotic ants. In this system, we investigated how positive feedback between mutualistic plants and ant colonies influenced population processes at two scales: (1) how modular organisms such as plants and ant colonies grew, or eta-demography, and (2) how populations grew, or N-demography. We found evidence of positive feedback between ant colony and plant growth rates. Plants with mutualistic ants (Azteca spp. and Myrmelachista schumanni) grew in a geometric or autocatalytic manner, such that the largest plants grew the most. By contrast, the growth of plants with parasitic ants (Allomerus octoarticulatus) saturated. Ant colonies occupied new domatia as fast as plants produced them, suggesting that mutualistic ant colonies also grew geometrically or autocatalytically to match plant growth. Plants became smaller when they lost ants. While unoccupied, plants continued to become smaller until they had lost all or nearly all their domatia. Hence, the loss of mutualistic ants limited plant growth. C. nodosa and D. hirsuta live longer than their ant symbionts and were sometimes recolonized after losing ants, which again promoted plant growth. Plant growth had fitness consequences for ants and plants; mortality and fecundity depended on plant size. Positive feedback between ants and plants allowed a few plants and ant colonies to become very large; these probably produced the majority of offspring in the next generation.
PMID: 19569374 [PubMed - in process]
Prioritized phenotypic responses to combined predators in a marine snail.
Ecology. 2009 Jun;90(6):1659-69
Authors: Bourdeau PE
Although many species face numerous predators in nature, the combined impact of multiple predators on the inducible defenses of prey has rarely been studied. Prey may respond with an intermediate phenotype that balances the risk from several sources or may simply respond to the most dangerous predator. I examined the separate and combined effects of the presence of shell-breaking (crabs, Cancer productus) and shell-entry (seastars, Pisaster ochraceus) predators fed conspecific snails on the defensive shell morphology and antipredator behavior of a marine snail (Nucella lamellosa). When exposed to each feeding predator separately, snails responded with a combination of morphological defenses that reflect the attack mode of the predator and a generalized behavioral response. Snails responded to feeding crabs by increasing refuge use and producing a thick, rotund shell. Snails responded to feeding seastars with increased refuge use but produced elongate shells with high spires that allowed for greater retraction of the soft tissue. Seastar-induced phenotypes reduced susceptibility to seastars relative to crab-induced phenotypes, but crab-induced phenotypes did not significantly reduce susceptibility to crabs, indicating an asymmetrical functional trade-off. When feeding predators were combined, snails produced a morphological phenotype similar to that expressed in the presence of the predator that imposed the highest mortality at the population level, suggesting that predator-induced morphology was prioritized according to predation risk. These results suggest that prioritizing conflicting defenses according to predator danger may be a common strategy for prey responding to combined predators, particularly in conjunction with generalized behavioral responses that reduce overall risk in multiple-predator environments.
PMID: 19569380 [PubMed - in process]
Sex effects on life span and senescence in the wild when dates of birth and death are unknown.
Ecology. 2009 Jun;90(6):1698-707
Authors: Zajitschek F, Brassil CE, Bonduriansky R, Brooks RC
Males and females allocate and schedule reproductive effort in very different ways. Because the timing and amount of reproductive effort influence survival and thus the optimization of life histories, mortality and senescence are predicted to be sex specific. However, age-specific mortality rates of wild animals are often difficult to quantify in natural populations. Studies that report mortality rates from natural populations are, therefore, almost entirely confined to long-lived, easy-to-track species such as large mammals and birds. Here, we employ a novel approach using capture-mark-recapture data from a wild population of black field crickets (Teleogryllus commodus) to test for sex differences in demographic aging. In this species, the age of captured adults cannot be readily determined, and animals cannot be reliably captured or observed every night, resulting in demographic data on individuals whose dates of birth and death are unknown. We implement a recently developed life-table analysis for wild-caught individuals of unknown age, in combination with a well-established capture-mark-recapture methodology that models probabilistic dates of death. This unified analytical framework makes it possible to test for aging in wild, hard-to-track animals. Using these methods to fit Gompertz models of age-specific mortality, we show that male crickets have higher mortality rates throughout life than female crickets. Furthermore, males and females both exhibit increasing mortality rates with age, indicating senescence, but the rate of senescence is not sex specific. Thus, observed sex differences in longevity are probably due to differences in baseline mortality rather than aging. Our findings illustrate the complexity of the relationships between sex, background mortality, and senescence rate in wild populations, showing that the elevated mortality rate of males need not be coupled with an elevated rate of aging.
PMID: 19569384 [PubMed - in process]
Health assessment of free-ranging three-banded (Tolypeutes matacus) and nine-banded (Dasypus novemcinctus) armadillos in the Gran Chaco, Bolivia.
J Zoo Wildl Med. 2009 Jun;40(2):245-56
Authors: Deem SL, Noss AJ, Fiorello CV, Manharth AL, Robbins RG, Karesh WB
The Gran Chaco, Bolivia, has a total of seven species of armadillos with the three-banded (Tolypeutes matacus) and nine-banded (Dasypus novemcinctus) the most commonly hunted by the local Isoseo-Guarani people. Armadillos are known carriers of zoonotic pathogens, including Mycobacterium leprae, Toxoplasma gondii, and Trypanosoma cruzi; thus human handling and consumption of these species may have a significant public health impact. A health assessment that included physical examinations, hematology, plasma biochemical analyses, levels of exposure to selected infectious agents, and endoparasite and ectoparasite identification was performed on nine-banded and three-banded armadillos in the Gran Chaco, Bolivia. Based on clinical findings, the general health of these armadillos was rated as good. However, many of the nine-banded armadillos (64%) had abrasions and wounds, probably related to the capture method. The blood value results from a subset of these armadillos are presented as baseline values for free-ranging populations of both these species in Bolivia. Serologic antibody tests for M. leprae were negative in three-banded (n = 8) and nine-banded (n = 2) armadillos. Three-banded armadillos were antibody positive for Eastern equine encephalitis virus (8/8; 100%) and Saint Louis encephalitis virus (5/8; 62.5%). Two of 12 (16.7%) three-banded armadillos tested were antigen positive for Dirofilaria immitis. Nine-banded armadillos were antibody positive for T. gondii (3/9; 33.3%), Eastern equine encephalitis virus (5/8; 62.5%), and T. cruzi (2/9; 22.2%). Two of eight (25%) nine-banded armadillos were antigen positive for D. immitis. A number of endo- and ectoparasites were identified in/on both species of armadillos. Results from this study support the possibility that the handling and consumption of these species by the local Isoseo-Guarani people may have a public health impact.
PMID: 19569470 [PubMed - in process]
Parasites of selected reptiles of the National Zoological Garden, Sri Lanka.
J Zoo Wildl Med. 2009 Jun;40(2):272-5
Authors: Fernando SP, Udagama-Randeniya PV
The National Zoological Garden plays a vital role in conservation of reptiles in Sri Lanka. Since parasitic infestations of captive reptiles can impact their health, a survey for intestinal parasites and ectoparasites was conducted on 19 selected reptilian species (14 snakes, four chelonians, and one crocodilian) housed at the National Zoological Garden, Sri Lanka. Of the reptiles screened, 62% (N = 139) were infected with parasites; 66% and 24% exclusively harbored intestinal and ecto parasites, respectively, while 10% carried both types of parasites. Three ticks (Ixodidae), two adult cestodes, plerocercoid larvae, and four nematode species were recovered during this survey. Three types of nematode ova and a single type of digenian ova, protozoan cysts, L3 nematode larvae, and a protozoan were detected in the feces. In this first systematic survey of reptilian parasites in Sri Lanka, four new host-parasite records are documented.
PMID: 19569473 [PubMed - in process]
Comparative genomics of MAP kinase and calcium-calcineurin signalling components in plant and human pathogenic fungi.
Fungal Genet Biol. 2009 Apr;46(4):287-98
Authors: Rispail N, Soanes DM, Ant C, Czajkowski R, Grnler A, Huguet R, Perez-Nadales E, Poli A, Sartorel E, Valiante V, Yang M, Beffa R, Brakhage AA, Gow NA, Kahmann R, Lebrun MH, Lenasi H, Perez-Martin J, Talbot NJ, Wendland J, Di Pietro A
Mitogen-activated protein kinase (MAPK) cascades and the calcium-calcineurin pathway control fundamental aspects of fungal growth, development and reproduction. Core elements of these signalling pathways are required for virulence in a wide array of fungal pathogens of plants and mammals. In this review, we have used the available genome databases to explore the structural conservation of three MAPK cascades and the calcium-calcineurin pathway in ten different fungal species, including model organisms, plant pathogens and human pathogens. While most known pathway components from the model yeast Saccharomyces cerevisiae appear to be widely conserved among taxonomically and biologically diverse fungi, some of them were found to be restricted to the Saccharomycotina. The presence of multiple paralogues in certain species such as the zygomycete Rhizopus oryzae and the incorporation of new functional domains that are lacking in S. cerevisiae signalling proteins, most likely reflect functional diversification or adaptation as filamentous fungi have evolved to occupy distinct ecological niches.
PMID: 19570501 [PubMed - in process]
Effects of mining-derived metals on riffle-dwelling benthic fishes in Southeast Missouri, USA.
Ecotoxicol Environ Saf. 2009 Jun 29;
Authors: Allert AL, Fairchild JF, Schmitt CJ, Besser JM, Brumbaugh WG, Olson SJ
We studied the ecological effects of mining-derived metals on riffle-dwelling benthic fishes at 16 sites in the Viburnum Trend lead-zinc mining district of southeast Missouri. Fish community attributes were compared to watershed features and to physical and chemical variables including metal concentrations in sediment pore water and fish. Ozark sculpin (Cottus hypselurus), rainbow darter (Etheostoma caeruleum), Ozark madtom (Noturus albater), and banded sculpin (Cottus carolinae) were the most abundant fishes collected. Species richness and density of riffle-dwelling benthic fishes were negatively correlated with metal concentrations in pore water and in fish. Sculpin densities were also negatively correlated with metal concentrations in pore water and in fish, but positively correlated with distance from mines and upstream watershed area. These findings indicate that metals associated with active lead-zinc mining adversely affect riffle-dwelling benthic fishes downstream of mining areas in the Viburnum Trend. Sculpins may be useful as a sentinel species for assessing mining-related impacts on fish communities.
PMID: 19570577 [PubMed - as supplied by publisher]
Aggressive use of Batesian mimicry by an ant-like jumping spider.
Biol Lett. 2009 Jul 1;
Authors: Nelson XJ, Jackson RR
Batesian and aggressive mimicry are united by deceit: Batesian mimics deceive predators and aggressive mimics deceive prey. This distinction is blurred by Myrmarachne melanotarsa, an ant-like jumping spider (Salticidae). Besides often preying on salticids, ants are well defended against most salticids that might target them as potential prey. Earlier studies have shown that salticids identify ants by their distinctive appearance and avoid them. They also avoid ant-like salticids from the genus Myrmarachne. Myrmarachne melanotarsa is an unusual species from this genus because it typically preys on the eggs and juveniles of ant-averse salticid species. The hypothesis considered here is that, for M. melanotarsa, the distinction between Batesian and aggressive mimicry is blurred. We tested this by placing female Menemerus sp. and their associated hatchling within visual range of M. melanotarsa, its model, and various non-ant-like arthropods. Menemerus is an ant-averse salticid species. When seeing ants or ant mimics, Menemerus females abandoned their broods more frequently than when seeing non-ant-like arthropods or in control tests (no arthropods visible), as predicted by our hypothesis that resembling ants functions as a predatory ploy.
PMID: 19570776 [PubMed - as supplied by publisher]
DNA content and distribution in ancient feathers and potential to reconstruct the plumage of extinct avian taxa.
Authors: Rawlence NJ, Wood JR, Armstrong KN, Cooper A
Feathers are known to contain amplifiable DNA at their base (calamus) and have provided an important genetic source from museum specimens. However, feathers in subfossil deposits generally only preserve the upper shaft and feather 'vane' which are thought to be unsuitable for DNA analysis. We analyse subfossil moa feathers from Holocene New Zealand rockshelter sites and demonstrate that both ancient DNA and plumage information can be recovered from their upper portion, allowing species identification and a means to reconstruct the appearance of extinct taxa. These ancient DNA sequences indicate that the distal portions of feathers are an untapped resource for studies of museum, palaeontological and modern specimens. We investigate the potential to reconstruct the plumage of pre-historically extinct avian taxa using subfossil remains, rather than assuming morphological uniformity with closely related extant taxa. To test the notion of colour persistence in subfossil feathers, we perform digital comparisons of feathers of the red-crowned parakeet (Cyanoramphus novaezelandiae novaezelandiae) excavated from the same horizons as the moa feathers, with modern samples. The results suggest that the coloration of the moa feathers is authentic, and computer software is used to perform plumage reconstructions of moa based on subfossil remains.
PMID: 19570784 [PubMed - as supplied by publisher]
A new plant virus with unique properties infecting Japanese holly fern.
J Gen Virol. 2009 Jul 1;
Authors: Valverde RA, Sabanadzovic S
A novel RNA virus with a bipartite genome has been found associated with an emerging disease affecting Japanese holly fern (Cyrtomium falcatum). Diseased Japanese holly fern plants showed a variety of foliar symptoms and reduction in size. The virus was transmitted by grafting, as well as through spores from an infected plant. Partially purified preparations of the virus from infected ferns contained quasi-spherical particles that ranged from 30-40 nm in diameter. Double-stranded RNA (dsRNA) analyses from diseased plants yielded two major molecules of approximately 6.2 and 3.0 kbp in size together with three other dsRNAs ascertained to be the replicative forms of sub-genomic RNAs. The organization of RNA1 of this novel virus resembles that of Raspberry bushy dwarf virus (gen. Idaeovirus), whereas the genomic RNA2 showed a distinct organization and evolutionary origin. Results of this study indicate that the virus detected in diseased ferns is an undescribed phytovirus for which the name Japanese holly fern mottle virus (JHFMoV) is proposed. Furthermore, we postulate that JHFMoV has enough distinguishing features to represent a type species of a new genus of plant viruses. Taking into account the original host of the virus, we propose the name Pteridovirus for this taxon.
PMID: 19570959 [PubMed - as supplied by publisher]
Molecular analysis and chemical evaluation of ephedra plants in mongolia.
Biol Pharm Bull. 2009 Jul;32(7):1235-43
Authors: Kitani Y, Zhu S, Omote T, Tanaka K, Batkhuu J, Sanchir C, Fushimi H, Mikage M, Komatsu K
Ephedrae herba has been used in traditional Chinese and Japanese (Kampo) medicine from ancient times, with the primary resource being in China. In the present study, a field survey as well as molecular and chemical assessments were conducted on Ephedra plants in Mongolia to clarify whether they could be an alternative resource of the Ephedrae herba used in Japanese Kampo medicine. Ephedra sinica, E. equisetina, E. przewalskii, E. regeliana, E. monosperma and an unknown taxon (ESP) collected in Mongolia were divided into 9 genotypes on the basis of nucleotide sequences of 18S ribosomal RNA (rRNA) gene and trnK gene. E. sinica, E. equisetina, and E. monosperma presented completely identical sequences to the corresponding species from China. The sequences of trnK gene and 18S rRNA gene provide a useful index for identification and taxonomic classification of Mongolian Ephedra plants. Quantitative analysis of 5 ephedrine alkaloids revealed that almost all Mongolian Ephedra plants contained high amounts of total ephedrine alkaloids (TAs, 1.86-4.90%) and a high percentage of pseudoephedrine in TAs differed obviously from the Chinese. E. sinica and E. equisetina found in eastern and central Mongolia, showing total contents of ephedrine and pseudoephedrine higher than 1.43%, were potential new resources of Japanese Pharmacopoeia grade Ephedrae herba.
PMID: 19571392 [PubMed - in process]
Clinical Challenges in Addressing Resistance to Antimicrobial Drugs in the Twenty-First Century.
Clin Pharmacol Ther. 2009 Jul 1;
Authors: Septimus EJ, Kuper KM
It has been more than 60 years since Alexander Fleming discovered the drug that came to be known as penicillin. Antibiotics are now one of the most frequently used medications in the United States and are prescribed by medical professionals in almost every specialty. The past decade has seen an alarming increase in the number of pathogens that are resistant to antimicrobial drugs, in the hospital as well as in the community.(1) Among the gram-positive pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus species are the biggest threats. The situation is even more alarming with respect to gram-negative pathogens, especially because there are currently no late clinical trials involving new anti-infective drugs that are active against these pathogens.Clinical Pharmacology & Therapeutics (2009); advance online publication 1 July 2009. doi:10.1038/clpt.2009.122.
PMID: 19571803 [PubMed - as supplied by publisher]
[In vitro activity of anidulafungin. Comparison with the activity of other echinocandins]
Enferm Infecc Microbiol Clin. 2008 Dec;26 Suppl 14:7-13
Authors: Martn Mazuelos E, Rodrguez-Tudela JL
Anidulafungin is a new echinocandin that acts by inhibiting (1,3)-beta-D-glucan synthesis in the fungal cell wall. This agent is a semisynthetic lipopeptide synthesized from a fermentation product of Aspergillus nidulans. The spectrum of activity of anidulafungin includes Candida and Aspergillus, the two main etiological agents causing invasive fungal infections. This drug is also active against strains of these genera resistant to azoles or amphotericin B. However, anidulafungin is not active against Cryptococcus spp., Trichosporon spp., Fusarium spp. or Mucorales spp. Data on the activity of this drug against other species are limited and do not allow conclusions to be drawn or recommendations to be made. Echinocandin resistance is uncommon and has little clinical relevance.
PMID: 19572429 [PubMed - in process]
[Role of anidulafungin in critically ill patients]
Enferm Infecc Microbiol Clin. 2008 Dec;26 Suppl 14:35-43
Authors: Borges S M, Garnacho Montero J
The most frequent invasive fungal infections in critically ill patients are invasive candidiasis, among which is candidemia. In the last few years, these infections have become more common in intensive care units (ICU), including those produced by species other than Candida albicans. This phenomenon may lead to the development of species resistant to antifungal agents. To start the most appropriate treatment, early diagnosis of the infection is essential, which would reduce empirical antibiotic treatment and increase the proportion of advanced or directed antibiotic therapy. Given the poor reliability of the available diagnostic techniques, new strategies are currently being employed in the ICU, such as the use of scores to evaluate the presence of fungal infections. The therapeutic arsenal against these infections has been increased and the introduction of anidulafungin represents the addition of a highly appropriate drug for the treatment of invasive candidiasis in immunocompetent critically ill patients.
PMID: 19572433 [PubMed - in process]
