Leptospira interrogans serotype pomona in Saskatchewan: isolation from a naturally infected striped skunk

Leptospira interrogans serotype pomona was isolated from the kidneys of a normal striped skunk (Mephitis mephitis hudsonicus) collected near Kindersley, Saskatchewan. Although there were no gross lesions, small foci of chronic interstitial nephritis were observed microscopically. This is the first reported isolation of serotype pomona for the prairie provinces.     

Polymorphonuclear neutrophil-mediated antibody-dependent cell cytotoxicity of herpesvirus-infected cells: ultrastructural studies

Bovine polymorphonuclear neutrophils (PMN) can mediate antibody-dependent cell cytotoxicity (ADCC) of herpesvirus-infected cells. Since cytotoxicity occurs only in the presence of PMN and specific antiviral antibody, but not until viral membrane antigens are expressed on the target cell, it is concluded that antibody must recognize viral membrane antigens before cytotoxicity can occur. Cytotoxicity also requires very close contact between the target cell and the PMN cell. These interactions occur as early as 1 h after incubating antibody, infected cells, and PMN, but the actual lysis and release of intracellular components occur over an extended period. It was assumed that degranulation was not involved in the initiation of cytotoxicity, but was involved in the final stage of destruction. The mechanism of lysis is proposed to involve the interaction of PMN membranes with target cell membranes with subsequent reorganization and activation of the PMN plasma membrane at points of contact with the target cell. This results in possible production of transmembrane channels which allows for the release of target cell contents.     

Optimization of RAPD‐PCR conditions in cattle

Abstract

Random Amplified Polymorphic DNA polymerase chain reaction (RAPD‐PCR) is a fast and easy way of identifying DNA polymorphisms generated from several regions of the genome. This could expedite the process of identifying informative polymorphic markers that may be linked to important genes controlling economic traits. In cattle, failure to obtain consistent amplification patterns in RAPD‐PCR has been a cause for concern. This has been attributed to the fact that decamer primers that are used in RAPD‐PCR reactions are likely to amplify regions of DNA where the primer‐template base pairing has some degree of mismatch and that these mismatches fail to repeat from reaction to reaction. This paper describes the use of tricine buffer along with changes in reaction components and thermal cycling conditions that has yielded consistent and reproducible RAPD‐PCR amplifications using single primers and double primer combinations on bovine DNA.     

Taxonomic status of southern South American Conepatus (Carnivora: Mephitidae)

Despite recent taxonomic evaluations of Mephitidae and North American hog‐nosed skunks, southern South American species of Conepatus have not been thoroughly examined in a systematic context. Conepatus chinga and Conepatus humboldtii were described more than 150 years ago, based on external characters such as hair coloration and size. Although historically recognized as valid species, to date no detailed systematic analysis has been performed for either of these taxa. Herein, we evaluated the taxonomic status of C. chinga and C. humboldtii within the southern part of South America using geometric morphometrics of the skull and mandible, mitochondrial DNA analysis using the cytochrome b and cytochrome oxidase c subunit I genes, and also control region and pelage pattern variation. We failed to find morphological (skull shape and pelage coloration patterns) or molecular differences between these two species; thus, we considered that the specimens assigned to C. chinga and C. humboldtii belong to the same species. Our results indicate that environmental variation seems to be responsible for shape and size variation in Conepatus skulls from southern South America. © 2013 The Linnean Society of London     

Analysing freshwater fish biodiversity records and respective conservation areas in Spain

The number of threatened freshwater fish species in Spain is among the highest recorded in Europe and includes a high percentage of endemic taxa. Investigated were the distribution of Spanish freshwater fish to identify priority areas for conservation and assess the extent to which freshwater fish are included in the existing network of protected areas. Considered were those threatened species recorded in the Spanish National inventories. From these data, several biodiversity indices were calculated and analysed. The results reveal important discrepancies between the national and international assessments of conservation status, whereby the current Spanish national catalogue needs updating to reconcile these inconsistencies. Several important areas for the conservation of freshwater fish lie outside protected areas. The results encourage the establishment of protected areas specifically for freshwater environments. An extensive database of Spanish freshwater fish species is needed to redefine priority areas and to maintain freshwater biodiversity.     

Length–weight relationships of freshwater fishes of the Alto Madre de Dios River (Manu Biosphere Reserve,Peru)

The present work provides the estimates of morphometric relationships for 22 native freshwater fish species (11 Characidae, five Loricariidae, two Heptapteridae, one Astroblepidae, one Crenuchidae, one Curimatidae and one Erythrinidae) collected in the Alto Madre de Dios River (Cuzco and Madre de Dios, Peru) in June 2012 using a mobile backpack electrofishing unit. These are the first length–weight relationships reported for 24 species, mostly endemic to the Amazonian basin. Knowledge regarding these biometric relationships can be relevant in the management and conservation of the local fishes and fisheries.     

Enhanced prostacyclin formation and Wnt signaling in sclerostin deficient osteocytes and bone

We show that prostacyclin production is increased in bone and osteocytes from sclerostin (Sost) knockout mice which have greatly increased bone mass. The addition of prostacyclin or a prostacyclin analog to bone forming osteoblasts enhances differentiation and matrix mineralization of osteoblasts. The increase in prostacyclin synthesis is linked to increases in β-catenin concentrations and activity as shown by enhanced binding of lymphoid enhancer factor, Lef1, to promoter elements within the prostacyclin synthase promoter. Blockade of Wnt signaling reduces prostacyclin production in osteocytes. Increased prostacyclin production by osteocytes from sclerostin deficient mice could potentially contribute to the increased bone formation seen in this condition.     

Retracing micro-epidemics of Chagas disease using epicenter regression

Vector-borne transmission of Chagas disease has become an urban problem in the city of Arequipa, Peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. The lack of obvious clinical disease in Arequipa has led to speculation that the local strain of the etiologic agent, Trypanosoma cruzi, has low chronic pathogenicity. The long asymptomatic period of Chagas disease leads us to an alternative hypothesis for the absence of clinical cases in Arequipa: transmission in the city may be so recent that most infected individuals have yet to progress to late stage disease. Here we describe a new method, epicenter regression, that allows us to infer the spatial and temporal history of disease transmission from a snapshot of a population's infection status. We show that in a community of Arequipa, transmission of T. cruzi by the insect vector Triatoma infestans occurred as a series of focal micro-epidemics, the oldest of which began only around 20 years ago. These micro-epidemics infected nearly 5% of the community before transmission of the parasite was disrupted through insecticide application in 2004. Most extant human infections in our study community arose over a brief period of time immediately prior to vector control. According to our findings, the symptoms of chronic Chagas disease are expected to be absent, even if the strain is pathogenic in the chronic phase of disease, given the long asymptomatic period of the disease and short history of intense transmission. Traducción al espa?ol disponible en Alternative Language Text S1/A Spanish translation of this article is available in Alternative Language Text S1.     

A history of chagas disease transmission, control, and re-emergence in peri-rural La Joya, Peru

Background

The history of Chagas disease control in Peru and many other nations is marked by scattered and poorly documented vector control campaigns. The complexities of human migration and sporadic control campaigns complicate evaluation of the burden of Chagas disease and dynamics of Trypanosoma cruzi transmission.

Methodology/Principal Findings

We conducted a cross-sectional serological and entomological study to evaluate temporal and spatial patterns of T. cruzi transmission in a peri-rural region of La Joya, Peru. We use a multivariate catalytic model and Bayesian methods to estimate incidence of infection over time and thereby elucidate the complex history of transmission in the area. Of 1,333 study participants, 101 (7.6%; 95% CI: 6.2–9.0%) were confirmed T. cruzi seropositive. Spatial clustering of parasitic infection was found in vector insects, but not in human cases. Expanded catalytic models suggest that transmission was interrupted in the study area in 1996 (95% credible interval: 1991–2000), with a resultant decline in the average annual incidence of infection from 0.9% (95% credible interval: 0.6–1.3%) to 0.1% (95% credible interval: 0.005–0.3%). Through a search of archival newspaper reports, we uncovered documentation of a 1995 vector control campaign, and thereby independently validated the model estimates.

Conclusions/Significance

High levels of T. cruzi transmission had been ongoing in peri-rural La Joya prior to interruption of parasite transmission through a little-documented vector control campaign in 1995. Despite the efficacy of the 1995 control campaign, T. cruzi was rapidly reemerging in vector populations in La Joya, emphasizing the need for continuing surveillance and control at the rural-urban interface.