Diversity of Francisella Species in Environmental Samples from Martha’s Vineyard, Massachusetts

We determined whether Francisella spp. are present in water, sediment, and soil from an active tularemia natural focus on Martha’s Vineyard, Massachusetts, during a multiyear outbreak of pneumonic tularemia. Environmental samples were tested by polymerase chain reaction (PCR) targeting Francisella species 16S rRNA gene and succinate dehydrogenase A (sdhA) sequences; evidence of the agent of tularemia was sought by amplification of Francisella tularensis-specific sequences for the insertion element ISFTu2, 17-kDa protein gene tul4, and the 43-kDa outer membrane protein gene fopA. Evidence of F. tularensis subsp. tularensis, the causative agent of the human infections in this outbreak, was not detected from environmental samples despite its active transmission among ticks and animals in the sampling site. Francisella philomiragia was frequently detected from a brackish-water pond using Francisella species PCR targets, and subsequently F. philomiragia was isolated from an individual brackish-water sample. Distinct Francisella sp. sequences that are closely related to F. tularensis and Francisella novicida were detected from samples collected from the brackish-water pond. We conclude that diverse Francisella spp. are present in the environment where human cases of pneumonic tularemia occur

Infección por Theileria annae en un perro esplenectomizado

La babesiosis canina es una enfermedad infecciosa de distribución mundial debida a la proliferación en los hematíes del perro de unas babesias específicas transmitidas por garrapatas. Si bien ha sido tradicionalmente asumido que las únicas especies que causan enfermedad en la especie canina son Babesia canis y Babesia gibsoni, publicaciones recientes demuestran que una tercera especie (Theileria annae) también puede causar una enfermedad muy severa. Este trabajo presenta el segundo caso publicado de esta forma de Theileria annae en un perro de 14 años, de raza Basset Hound, esplenectomizado cinco meses antes, que se presentó en la clínica veterinaria con signos de hipertermia, hemoglobinuria, temblores y apatía. El estudio de laboratorio constató una acusada anemia hemolítica regenerativa y una intensa trombocitopenia como datos más característicos. En la extensión de sangre periférica se visualizaron múltiples merozoítos intra (22%) y extraeritrocitarios de pequeño tamaño (1-2 micras), forma anular y presentación única en la mayoría de hematíes. La prontitud del diagnóstico y del tratamiento específico con dipropionato de imidocarb hizo que el cuadro clínico evolucionase con rapidez hacia la curación, en contra de lo que es habitual en los animales esplenectomizados.

Nonrandom Distribution of Vector Ticks (Dermacentor variabilis) Infected by Francisella tularensis

The island of Martha's Vineyard, Massachusetts, is the site of a sustained outbreak of tularemia due to Francisella tularensis tularensis. Dog ticks, Dermacentor variabilis, appear to be critical in the perpetuation of the agent there. Tularemia has long been characterized as an agent of natural focality, stably persisting in characteristic sites of transmission, but this suggestion has never been rigorously tested. Accordingly, we sought to identify a natural focus of transmission of the agent of tularemia by mapping the distribution of PCR-positive ticks. From 2004 to 2007, questing D. variabilis were collected from 85 individual waypoints along a 1.5 km transect in a field site on Martha's Vineyard. The positions of PCR-positive ticks were then mapped using ArcGIS. Cluster analysis identified an area approximately 290 meters in diameter, 9 waypoints, that was significantly more likely to yield PCR-positive ticks (relative risk 3.3, P = 0.001) than the rest of the field site. Genotyping of F. tularensis using variable number tandem repeat (VNTR) analysis on PCR-positive ticks yielded 13 different haplotypes, the vast majority of which was one dominant haplotype. Positive ticks collected in the cluster were 3.4 times (relative risk = 3.4, P<0.0001) more likely to have an uncommon haplotype than those collected elsewhere from the transect. We conclude that we have identified a microfocus where the agent of tularemia stably perpetuates and that this area is where genetic diversity is generated

Antibiotic Treatment of the Tick Vector Amblyomma americanum Reduced Reproductive Fitness

BACKGROUND: The lone star tick Amblyomma americanum is a common pest and vector of infectious diseases for humans and other mammals in the southern and eastern United States. A Coxiella sp. bacterial endosymbiont was highly prevalent in both laboratory-reared and field-collected A. americanum. The Coxiella sp. was demonstrated in all stages of tick and in greatest densities in nymphs and adult females, while a Rickettsia sp. was less prevalent and in lower densities when present. METHODOLOGY/PRINCIPAL FINDINGS: We manipulated the numbers of both bacterial species in laboratory-reared A. americanum by injecting engorged nymphs or engorged, mated females with single doses of an antibiotic (rifampin or tetracycline) or buffer alone. Burdens of the bacteria after molting or after oviposition were estimated by quantitative polymerase chain reaction with primers and probes specific for each bacterial species or, as an internal standard, the host tick. Post-molt adult ticks that had been treated with rifampin or tetracycline had lower numbers of the Coxiella sp. and Rickettsia sp. and generally weighed less than ticks that received buffer alone. Similarly, after oviposition, females treated previously with either antibiotic had lower burdens of both bacterial species in comparison to controls. Treatment of engorged females with either antibiotic was associated with prolonged time to oviposition, lower proportions of ticks that hatched, lower proportions of viable larvae among total larvae, and lower numbers of viable larvae per tick. These fitness estimators were associated with reduced numbers of the Coxiella sp. but not the Rickettsia sp. CONCLUSION/SIGNIFICANCE: The findings indicate that the Coxiella sp. is a primary endosymbiont, perhaps provisioning the obligately hematophagous parasites with essential nutrients. The results also suggest that antibiotics could be incorporated into an integrated pest management plan for control of these and other tick vectors of disease

Biology of Francisella tularensis Subspecies holarctica Live Vaccine Strain in the Tick Vector Dermacentor variabilis

Background: The c-proteobacterium Francisella tularensis is the etiologic agent of seasonal tick-transmitted tularemia epizootics in rodents and rabbits and of incidental infections in humans. The biology of F. tularensis in its tick vectors has not been fully described, particularly with respect to its quanta and duration of colonization, tissue dissemination, and transovarial transmission. A systematic study of the colonization of Dermacentor variabilis by the F. tularensis subsp. holarctica live vaccine strain (LVS) was undertaken to better understand whether D. variabilis may serve as an inter-epizootic reservoir for F. tularensis. Methodology/Principal Findings: Colony-reared larva, nymph, and adult D. variabilis were artificially fed LVS via glass capillary tubes fitted over the tick mouthparts, and the level of colonization determined by microbial culture. Larvae and nymphs were initially colonized with 8.860.8610 1 and 1.160.03610 3 CFU/tick, respectively. Post-molting, a significant increase in colonization of both molted nymphs and adults occurred, and LVS persisted in 42 % of molted adult ticks at 126 days post-capillary tube feeding. In adult ticks, LVS initially colonized the gut, disseminated to hemolymph and salivary glands by 21 days, and persisted up to 165 days. LVS was detected in the salivary secretions of adult ticks after four days post intra-hemocoelic inoculation, and LVS recovered from salivary gland was infectious to mice with an infectious dose 50 % of 3 CFU. LVS in gravid female ticks colonized via the intra-hemocoelic route disseminated to the ovaries and then t

Il mercato antiquariale nella Venezia di Ruskin. L'arte medievale in Germania

I primi viaggi di Ruskin a Venezia cadono durante la dominazione austriaca, una lunga fase che vede una dispersione di materiali medievali veneziani che sono divenuti oggetto d’interesse per un mercato che risponde a sollecitazioni diverse: privati collezionisti, amatori e turisti stranieri che cercano “souvenir” ma anche committenze elevate finalizzate alla costituzione di musei e luoghi evocativi. È questo il caso dell’imponente acquisto negli anni Quaranta ( committente Federico Guglielmo di Prussia) di sculture antiche e medievali in Italia che andranno a costituire un importante nucleo per il museo di arte medievale e bizantina dei musei di stato in corso di costruzione. Tra queste si trova un gruppo interessante di opere veneziane acquistate tutte presso un unico commerciante veneziano (Pajaro). Anche il fratello di Federico Gugliemo, Carlo, acquista arte veneziana per ricreare nel castello di Glienicke un chiostro veneziano. Ancora: la Friedenkirche a Potsdam viene ornata da un mosaico acquistato a Murano dalla demolita chiesa di san Cipriano. Frammenti e opere intere vanno quindi a costituire raccolte destinate al pubblico e alla sua educazione, oppure a impreziosire edifici neomedievali o evocativi. Una spoliazione che va in direzione opposta all’attenzione di Ruskin. L’occhio e la mano di Ruskin ci hanno consegnato documentazione grafica e visiva di un patrimonio in contesto. I suoi scritti sono animati dalla attenzione ad ogni frammento, come testimonianza di un fare che è anche storia. Delle esportazioni delle opere medievali resta traccia anche nella reazione di veneziani (Seguso in primis) e si può cogliere non solo negli scritti ma nelle azioni successive la crescita di una attenzione e una sensibilità per un patrimonio che verrà sentito come identitario. Dopo l’annessione all’Italia pur non cessando l’azione del mercato e le vendite possiamo riscontrare una dinamica non solo di attenzione e forte impegno nel restauro di monumenti significativi, ma anche la costituzione di musei dove trovano posto i frammenti emersi da restauri e le sculture decontestualizzate in nome di un nuovo spirito e di una attenzione di cui Ruskin è stato attivo promotore e protagonista

The Compressible Flow Past Various Plane Profiles Near Sonic Velocity

In an earlier report UM No.1117 by Gothert,the single-source method was applied to the compressible flow around circles, ellipses, lunes, and around an elongated body of revolution at different Mach numbers and the results compared as far as possible with the calculations by Lamla ad Busemann. Essentially, it was found that with favorable source arrangement the single-source method is in good agreement with the calculations of the same degree of approximation by.Lamla and Busemann. Near sonic velocity the number of steps must be increased considerably in order to sufficiently approximate the adiabatic curve. After exceeding a certain Mach number where local supersonic fields occur already, it was no longer possible, in spite of the substantially increased number of steps, to obtain a systematic solution because the calculation diverged. This result,was interpreted to mean that above this point of divergence the symmetrical type of flow ceases to exist and changes into the unsymmetrical type characterized by compressibility shocks