Black yeast-like fungi associated with Lethargic Crab Disease (LCD) in the mangrove-land crab, Ucides cordatus (Ocypodidae)

Lethargic Crab Disease (LCD) caused extensive epizootic mortality of the mangrove land crab Ucides cordatus (Brachyura: Ocypodidae) along the Brazilian coast, mainly in the Northeastern region. The disease was named after the symptoms of slow movement of infected crabs. Causative agents were suspected to be two black yeast-like fungi of the family Herpotrichiellaceae (ascomycete order Chaetothyriales), judged by infected tissue biopsies from moribund U. cordatus. The aim of the present study is to prove that two species are involved in the disease: the recently described black yeast Exophiala cancerae, but also a less virulent, hitherto undescribed fonsecaea-like species, introduced here as the novel species Fonsecaea brasiliensis. Strains were identified by ITS rDNA sequencing, and species borderlines were established by multilocus sequencing and AFLP analysis. Fonsecaea brasiliensis proved to be closely related to the pathogenic species Cladophialophora devriesii which originally was isolated from a systemic infection in a human patient. The virulence of F. brasiliensis is lower than that of E. cancerae, as established by artificial inoculation of mangrove crabs.     

Paleo-Eskimo mtDNA genome reveals matrilineal discontinuity in Greenland

The Paleo-Eskimo Saqqaq and Independence I cultures, documented from archaeological remains in Northern Canada and Greenland, represent the earliest human expansion into the New World's northern extremes. However, their origin and genetic relationship to later cultures are unknown. We sequenced a mitochondrial genome from a Paleo-Eskimo human by using 3400-to 4500-year-old frozen hair excavated from an early Greenlandic Saqqaq settlement. The sample is distinct from modern Native Americans and Neo-Eskimos, falling within haplogroup D2a1, a group previously observed among modern Aleuts and Siberian Sireniki Yuit. This result suggests that the earliest migrants into the New World's northern extremes derived from populations in the Bering Sea area and were not directly related to Native Americans or the later Neo-Eskimos that replaced them.     

Pathogenicity of <Emphasis Type="Italic">Stemphylium vesicarium</Emphasis> from different hosts causing brown spot in pear

Stemphylium vesicarium (teleomorph: Pleospora herbarum) is the causal agent of brown spot disease in pear. The species is also able to cause disease in asparagus, onion and other crops. Saprophytic growth of the fungus on plant debris is common. The objective of this study was to investigate whether isolates of S. vesicarium from different hosts can be pathogenic to pear. More than hundred isolates of Stemphylium spp. were obtained from infected pear fruits, dead pear leaves, dead grass leaves present in pear orchard lawns as well as from necrotic leaf parts of asparagus and onion. Only isolates originating from pear orchards, including isolates from dead grass leaves, were pathogenic on pear leaves or fruits in bioassays. Non-pathogenic isolates were also present in pear orchards. Stemphylium vesicarium from asparagus or onion, with one exception, were not pathogenic to pear. Analysis of the genetic variation between isolates using Amplified Fragment Length Polymorphism (AFLP) showed significant concordance with host plants. Isolates from asparagus or onion belonged to clusters separate from the cluster with isolates from pear or grass leaves collected in pear orchards. Multilocus sequencing of a subset of isolates showed that such isolates were similar to S. vesicarium.     

A new species of Embellisia,associated with skin disease of hyacinths

A new species of the genusEmbellisia (Hyphomycetes, Dematiaceae) was isolated from bulbs and leaves of various cultivars ofHyacinthus, Scilla andFreesia. It is characterized by dark, multiseptate conidia which are somewhat pointed at the apex and variable in shape and size. In contrast to other species of the genus it rarely forms chlamydospores in pure culture. The fungus was found on several locations in the Netherlands, and is also known in the USA and Germany. Inoculation experiments on several cultivars ofHyacinthus orientalis resulted in a high percentage of affected plants.Samenvatting Een nieuwe soort van het genusEmbellisia (Hyphomycetes, Dematiaceae),E. hyacinthi, werd geïsoleerd uit de buitenste bolrokken van cultivars vanHyacinthus orientalis. De schimmel is gekarakteriseerd door bruine, apicaal iets spitse conidiën met een wisselend aantal transversale, en dikwijls ook enkele longitudinale septa (Fig. 1), en de afwezigheid van duidelijk gedifferentieerde groepjes van chlamydosporen.Een sterk hierop gelijkende soort werd in 1876 beschreven door Massink alsCladosporium fasciculare Fr. Het opvallende voorkomen van longitudinale septa werd in zijn studie echter niet expliciet genoemd.WanneerEmbellisia hyacinthi wordt gekweekt op havermoutagar zijn na 5 dagen de meeste conidiën vrij lang, cylindrisch, met 3 of meer septa (Fig. 2a). Na langere tijd echter worden kleinere conidiën gevormd, zodat de variabiliteit der conidiën op dezelfde plaats groter wordt (Fig. 2b). Dit verschijnsel uit zich nog sterker op Czapekagar (Fig. 2c-d). Embellisia hyacinthi veroorzaakt kleine bruine plekjes op de buitenste bolrok van hyacint. Deze vorm van huidziekte is reeds lang bekend; de schimmel is ook in de USA en Duitsland gekonstateerd, en werd tevens geïsoleerd vanFreesia refracta enScilla sibirica. Soms ook komen langwerpige bladvlekken op de buitenste bladeren van hyacint voor. Een inoculatieproef werd gedaan met de cultivars la Victoire en Carnegie. De metEmbellisia hyacinthi geïnoculeerde planten vertoonden een aanzienlijk hoger aantastingspercentage dan die op het controleveld.     

Evaluation of molecular typing methods for Salmonella enterica serovar Typhimurium DT104 isolated in Germany from healthy pigs

The discriminatory power of four different DNA based typing methods was tested for the molecular subtyping of Salmonella Typhimurium phage type DT104 isolates. German DT104 strains (n = 133) originating from slaughter pigs were analysed by plasmid profiling, and 32 of them by pulsed-field gel electrophoresis (PFGE) using the restriction enzymes XbaI, SpeI or BlnI, random amplification of polymorphic DNA (RAPD) using 13 different primers and IS200 typing. A resulting subtyping scheme was obtained which is based on the most discriminatory power of the individual methods i.e. plasmid profiling and PFGE with all three enzymes. The index of discrimination obtained by the subtyping scheme was 0.909 closely approaching the maximum value of one. Although minor differences occurred in the molecular DNA pattern of single DT104 strains, a dominating subtyping pattern was observed confirming other studies which showed, that S. Typhimurium DT104 isolates are highly clonal.     

Cutaneous Alternaria infectoria infection in a dog in association with therapeutic immunosuppression for the management of immune‐mediated haemolytic anaemia

A 4‐year‐old, ovariohysterectomized, English springer spaniel on immunosuppressive therapy was re‐examined for the review of its immune‐mediated haemolytic anaemia and the recent development of skin lesions. For the 3 months since hospital discharge, the dog had been receiving 1.3 mg/kg prednisolone and 2.6 mg/kg ciclosporin, both administered orally twice daily. Physical examination revealed hepatomegaly and multiple, purulent, crusting, erosive to ulcerative lesions over different body areas. Onychorrhexis had occurred on one digit and the underlying corium had blackened. There were two proliferative and one plaque‐like lesions in the mouth. Thick walled fungal hyphae were detected in impression smears from all skin lesions and staining with periodic acid–Schiff’s stain confirmed the presence of multiple fungal hyphae and spores in all biopsies examined. Fungal culture isolated a heavy, pure growth of an Alternaria sp. which was identified as A. infectoria by sequencing the internal transcribed spacer 1 region of the rRNA gene. The animal’s condition prevented detailed investigation of the oral lesions. Withdrawal of the ciclosporin and reduction of the prednisolone dosage resulted in spontaneous resolution of the skin lesions within 40 days. Further gradual decrements in the prednisolone dosage to zero were carried out without recurrence of the immune‐mediated haemolytic anaemia. After 12 months, there has been no recurrence of either the skin lesions or the anaemia. To the authors’ knowledge, this is the first reported case of A. infectoria infection in a dog.     

Acid-induced cold gelation of globular proteins: effects of protein aggregate characteristics and disulfide bonding on rheological properties

The process of cold gelation of ovalbumin and the properties of the resulting cold-set gels were compared to those of whey protein isolate. Under the chosen heating conditions, most protein was organized in aggregates. For both protein preparations, the aggregates consisted of covalently linked monomers. Both types of protein aggregates had comparable numbers of thiol groups exposed at their surfaces but had clearly different shapes. During acid-induced gelation, the characteristic ordering caused by the repulsive character disappeared and was replaced by a random distribution. This process did not depend on aggregate characteristics and probably applies to any type of protein aggregate. Covalent bonds are the main determinants of the gel hardness. The formation of additional disulfide bonds during gelation depended on the number and accessibility of thiol groups and disulfide bonds in the molecule and was found to clearly differ between the proteins studied. However, upon blocking of the thiol groups, long fibrillar structures of ovalbumin contribute significantly to gel hardness, demonstrating the importance of aggregate shape.     

微小隐孢子虫核酸疫苗的研究

将编码C.parvum子孢子15kD CP15表面蛋白基因插入真核表达载体pCR.31( ）建重组质粒pCR3.1-15，然后经鼻粘膜免疫怀孕成年山羊，观察其免疫应答的产生情况及其对后代的保护力。结果表明：抗CP15抗体存在于免疫山羊的血浆和初乳中。pCR3.1-15经鼻腔免疫的怀孕山羊产生的免疫力能传给子代，使子代对C.parvum感染产生保护。CP15－DNA免疫母羊的后代比非免疫母羊的后代排出卵囊少，且排卵时间短。     

Ancient biomolecules from deep ice cores reveal a forested southern Greenland

It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of past flora and fauna. We show that high-altitude southern Greenland, currently lying below more than 2 kilometers of ice, was inhabited by a diverse array of conifer trees and insects within the past million years. The results provide direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.     

Ochroconis globalis infecting Atlantic salmon (Salmo salar), with a review of Ochroconis species in cold‐blooded animals

Necropsy examination of an adult Atlantic salmon (Salmo salar) from the Dalälven River in Sweden revealed numerous large, white nodules, with spherical cysts and granulomata in kidney and liver. Histopathology showed dark, septate, thin‐walled hyphae. The aetiologic agent was found to be an Ochroconis species (Venturiales) that differed from known fish‐associated species of the genus. Molecular phylogenetic studies of the culture (strain UIII09 = CBS 135766) demonstrated that Ochroconis globalis was concerned. The isolate proved to be susceptible to all investigated antifungals, as it is known for another Ochroconis species. The role of Ochroconis in opportunism of cold‐blooded animals was discussed, and the diagnostic methods using DNA sequences for routine identification of the fungus were proposed.