How metal-tolerant ecotypes of ectomycorrhizal fungi protect plants from heavy metal pollution

• Introduction   

Heavy metal pollution is a strong driver of above- and belowground communities and triggers evolutionary adaptation in organisms. This review provides an overview of our knowledge on the effects of toxic concentrations of metals on ectomycorrhizal populations and communities.     

Genetic diversity of Pasteurella species isolated from European vespertilionid bats

Pasteurella are an important cause of fatal infections in free-ranging bats, but the genetic diversity of bat-derived strains is unclear. In the current study, 81 Pasteurella strains associated with pneumonia, severe organ necroses and systemic infection in free-ranging European vespertilionid bats were characterized by biochemical and molecular typing methods. Genetic relationships and subspecies status of Pasteurella multocida strains were determined by comparative 16S rDNA and rpoB gene sequence analysis. In addition, 30 representatives of the bat-derived P. multocida strains were selected based on phenotypic and genotypic tests to be compared by pulsed-field gel electrophoresis using SmaI. Most (85%) of the Pasteurella strains obtained from free-ranging bats in this study represented P. multocida ssp. septica. P. multocida ssp. multocida and Pasteurella species B were also identified in a small number of isolates. PFGE analysis correlated well with the sequencing results and revealed a high genetic diversity among bat-derived strains of P. multocida ssp. septica. Strains sharing identical or closely related SmaI fragment patterns were cultured from bats of different species, geographic origins, and years of isolation. The presence of numerous different P. multocida strains allows the assumption that Pasteurella infections in vespertilionid bats are not solely based on intra- but also on inter-species transmission. And indeed, our results present evidence of P. multocida infections in bats following cat predation.     

Landscape elements as potential barriers and corridors for bees, wasps and parasitoids

Habitat loss and fragmentation in agricultural landscapes lead to severe declines of abundance and richness of many insect species in the remaining isolated semi-natural habitats. We analysed possible barrier effects of large hedges and corridor effects of narrow grass strips that were hypothesized to affect foraging and dispersal of hymenopterans. We selected calcareous grasslands in the vicinity of Göttingen (Germany), which harbour high Hymenoptera diversity and are starting points for foraging and dispersal in the landscape. We installed pan traps to sample bees (i) on the grasslands; (ii) on grassland edges behind adjacent hedges (potential barriers) and without hedges; (iii) on grass strips in 100 m distance to the grassland, which were connected or unconnected to the grassland; and (iv) unconnected (isolated) grass strips in 300 m and 750 m distance to test for corridor and isolation effects on abundance and species richness of foraging wild bees. Additionally we provided trap nests for bees, wasps and their parasitoids on the grasslands and the strips. Species abundance and richness declined with increasing isolation from grasslands for foraging solitary bees, trap-nesting bees, wasps and parasitoids, but not for foraging bumblebees. Hedges did not confine movement of foraging bees. We found no mitigating effects of (100 m) corridor strips on any of the observed groups. We conclude that conservation of semi-natural habitats as sources of bee and wasp diversity is important and that grass strips act as sinks rather than corridors when high quality patches are nearby.     

Endoscopic removal of a molariform supernumerary intranasal tooth (heterotopic polyodontia) in a horse

CASE DESCRIPTION: A 3-year-old Thoroughbred mare was evaluated because of abnormal upper respiratory tract sounds (that had become apparent during race training) of 3 to 4 months' duration. CLINICAL FINDINGS: On initial physical evaluation, there were no abnormal findings. During trotting, an abnormal upper airway expiratory sound was audible. Endoscopic examination revealed a small mass protruding into the right ventral nasal meatus. Radiographic images of the skull revealed no abnormal findings. Computed tomography of the head revealed an abnormal structure in the same location as the mass that was observed during endoscopy. The x-ray attenuation of the mass was identical to that of dental tissue. TREATMENT AND OUTCOME: The mass was surgically removed with endoscopic guidance. On gross examination, the excised mass appeared to be a nearly normal molariform tooth. Histologic examination revealed that it was a well-formed tooth, with no other associated cellular populations. The mass was determined to be a molariform supernumerary intranasal tooth. Six months following discharge from the hospital, the trainer reported that the abnormal respiratory tract sound was no longer audible. During a follow-up endoscopic examination performed at the training facility, no abnormalities were detected. CLINICAL RELEVANCE: In horses, an intranasal tooth should be considered as a differential diagnosis for expiratory stridor. Clear definitions of heterotopic polyodontia, dentigerous cyst, and temporal teratoma can be used to clinically diagnose these separate anomalies. In the horse of this report, computed tomographic findings contributed to determination of a diagnosis and formulation of a treatment plan.     

Serosurvey for Toxoplasma gondii in arctic foxes and possible sources of infection in the high Arctic of Svalbard

Samples (blood or tissue fluid) from 594 arctic foxes (Alopex lagopus), 390 Svalbard reindeer (Rangifer tarandus platyrhynchus), 361 sibling voles (Microtus rossiaemeridionalis), 17 walruses (Odobenus rosmarus), 149 barnacle geese (Branta leucopsis), 58 kittiwakes (Rissa tridactyla), and 27 glaucous gulls (Larus hyperboreus) from Svalbard and nearby waters were assayed for antibodies against Toxoplasma gondii using a direct agglutination test. The proportion of seropositive animals was 43% in arctic foxes, 7% in barnacle geese, and 6% (1 of 17) in walruses. There were no seropositive Svalbard reindeer, sibling voles, glaucous gulls, or kittiwakes. The prevalence in the arctic fox was relatively high compared to previous reports from canid populations. There are no wild felids in Svalbard and domestic cats are prohibited, and the absence of antibodies against T. gondii among the herbivorous Svalbard reindeer and voles indicates that transmission of the parasite by oocysts is not likely to be an important mechanism in the Svalbard ecosystem. Our results suggest that migratory birds, such as the barnacle goose, may be the most important vectors bringing the parasite to Svalbard. In addition to transmission through infected prey and carrion, the age-seroprevalence profile in the fox population suggests that their infection levels are enhanced by vertical transmission.     

Hematologic characteristics of captive western barred bandicoots (Perameles bougainville) from Western Australia

BACKGROUND: The western barred bandicoot (Perameles bougainville) is an Australian marsupial species now considered endangered as a consequence of habitat destruction and predation. A recently discovered papillomatosis syndrome is hindering efforts to repopulate this species. Hematology reference intervals have been lacking for P bougainville, preventing optimal interpretation of hematology results from wart-affected and clinically normal animals. OBJECTIVES: The purpose of this study was to establish hematology reference values and describe morphologic characteristics of blood cells of healthy western barred bandicoots. METHODS: Fifty-nine whole blood samples were collected by jugular venipuncture into EDTA from 47 clinically healthy captive western barred bandicoots at 3 locations on the Western Australian mainland. A CBC was performed using an ADVIA-120 analyzer. Data were compared on the basis of geographic location, sex, age, and lactation status, and reference intervals were calculated. Blood cell morphology was evaluated using light microscopy, and transmission and scanning electron microscopy. RESULTS: Significant differences were found based on sex (RBC indices, fibrinogen), age (% polychromatophilic RBCs), and geographic location (RBC, neutrophil, and lymphocyte counts, MCHC, % polychromatophilic RBCs, fibrinogen). Combined reference intervals were calculated for hemoglobin concentration (122-165 g/L), HCT (0.36-0.49 L/L), and total WBC (2.9-14.9 x 10(9)/L), monocyte (0-0.6 x 10(9)/L), eosinophil (0-0.9 x 10(9)/L), and total plasma protein (47-63 g/L) concentrations. Leukocyte, erythrocyte, and platelet morphology were similar to those of other marsupial peramelid species. Nuclei in neutrophils, monocytes, and eosinophils occasionally had an annular configuration. CONCLUSIONS: Reference intervals and blood cell morphology obtained in this study will be useful for the evaluation of laboratory data from ill animals and assist with population health monitoring of western barred bandicoots.