Mycobacterium tuberculosis infections in eight species at the National Zoological Gardens of South Africa, 1991-2001.     

Anita L Michel  Leon Venter  Ian W Espie  Morné L Coetzee 《Journal of zoo and wildlife medicine》2003,34(4):364-370

Between 1991 and 2001 a total of 12 cases of Mycobacterium tuberculosis infection in eight different species were recorded in the National Zoological Gardens of South Africa in Pretoria (Tshwane). The genetic relatedness between seven of the M. tuberculosis isolates was determined by IS6110 restriction fragment length polymorphism analysis. For the majority of isolates that were analyzed, a high degree of polymorphism suggested different sources of infection. Evidence of M. tuberculosis transmission between animals is reported in two chimpanzees (Pan troglodytes) housed together, from which samples were collected for analysis 29 mo apart.  相似文献   

Evaluation of normal triiodothyronine and tetraiodothyronine concentrations in llamas (Lama glama)     

B B Smith  E G Pearson  J Leon 《American journal of veterinary research》1989,50(8):1215-1219

Basal serum triiodothyronine (T3) and tetraiodothyronine (T4) concentrations have not been established for the llama (Lama glama). In addition, changes in T3 and T4 concentrations in response to thyroid-stimulating hormone (TSH) administration have not been determined, making clinical evaluation of problems referable to thyroid dysfunction difficult. In study 1, basal T3 and T4 concentrations were determined in serum samples collected from 132 clinically healthy llamas. The llamas were allotted to 3 groups: mature intact or neutered males (group I, n = 25), nonpregnant sexually mature females (group II, n = 21), and pregnant females (group III, n = 86). A mean concentration and a 95% confidence interval were computed for each group. An analysis of variance (ANOVA) indicated that a single confidence interval range (0.45 to 4.18, mean = 1.37 ng T3/ml) adequately defined the normal T3 concentrations for all groups. An ANOVA indicated that the T4 concentrations for the female populations (groups II and III) could be combined with a normal confidence interval range of 39 to 204 ng/ml (mean = 88 ng/ml), whereas a separate range (70 to 220 ng/ml, mean = 124 ng/ml) was determined for the male population. An ANOVA indicated that a single confidence interval range (0.0066 to 0.0321, mean = 0.0146) adequately defined the normal T3/T4 ratio for all groups. In study 2, T3 and T4 concentrations were evaluated in 10 healthy llamas immediately preceding and at 2, 4, 6, 8, and 24 hours after the IV administration of 3 IU of TSH/44 kg of body weight. The T3 and T4 concentrations were significantly higher by 2 hours after TSH administration in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Genetic analysis of feline caliciviruses associated with a hemorrhagic-like disease.     

Mohamed Abd-Eldaim  Leon Potgieter  Melissa Kennedy 《Journal of veterinary diagnostic investigation》2005,17(5):420-429

Feline calicivirus (FCV) is 1 of the most common causes of upper respiratory tract disease in cats. Other disease syndromes associated with FCV infection have been reported. Recently, calicivirus infection associated with a hemorrhagic-like disease leading to significant mortality in cats has been reported. The clinical signs are similar to those observed with the calicivirus of rabbit hemorrhagic disease. This study characterized 2 FCV isolates associated with hemorrhagic-like disease. Nucleotide sequencing of the complete genome has been done for these 2 isolates as well as for 4 additional isolates representing other disease syndromes. Previously reported sequence data for the entire genome of classical FCV (6 isolates) and a portion of the capsid gene for hemorrhagic-like FCV (3 isolates), isolated in different regions of United States were used in the genetic analysis. Sequence data were used to determine relationships among the isolates and any correlation with phenotype. Nucleotide sequence comparisons of the entire genome and individual open reading frames revealed high homology among all isolates. Data suggest that the virulence may have genetic determinants on the basis of phylogenetic clustering of the isolates associated with hemorrhagic-like disease.  相似文献   

Pre-parturition staphylococcal mastitis in primiparous replacement goats: persistence over lactation and sources of infection     

Iacome SC Jácome  Francisca GC Sousa  Candice MG De Leon  Denis A Spricigo  Mauro MS Saraiva  Patricia EN Givisiez  Wondwossen A Gebreyes  Rafael FC Vieira  Celso JB Oliveira 《Veterinary research》2014,45(1)

This investigation reported for the first time the occurrence of intramammary infections caused by Staphylococcus in primiparous replacement goats before parturition and the persistence of clinical Staphylococcus aureus infection during the lactation period. Subclinical infections, mainly caused by coagulase negative staphylococci (CoNS), did not persist during lactation. Genotyping analysis indicated that environment seems to play a moderate role as source of intramammary infections to goats before parturition, but causative agents of mastitis in lactating animals are not genotypically related to environmental staphylococci. The occurrence and persistence of intramammary infections in replacement goats demonstrate the need to consider those animals as potential sources of infections in dairy goat herds.  相似文献   

The effect of turf cutting on plant and arbuscular mycorrhizal spore recolonisation: Implications for heathland restoration     

Philippine Vergeer  Leon J.L. van den Berg  N. Joop Ouborg 《Biological conservation》2006,129(2):226-235

In two natural heathland vegetations, we analysed the effect of turf cutting on spore numbers of arbuscular mycorrhizal fungi (AMF). Next to this, we performed a controlled factorial experiment to examine the role of AMF for germination and establishment of Arnica montana in both turf cut and non-turf cut situations. AMF spore numbers decreased with soil depth, and, along with the topsoil, almost all AMF spores were removed with the removal of the acidified and/or eutrophied organic layer. Recolonisation of AMF spore numbers after turf cutting was slow: spore numbers of approximately 60-95 spores g⁻¹ dry soil were found two and a half years after turf cutting, corresponding with 55-70% of AMF spore numbers found in natural field populations of A. montana. Since AMF colonisation increased establishment and biomass, and decreased mortality of A. montana, it was suggested that lack of AMF after turf removal might complicate the establishment of this herbaceous species. Removal of organic material as a management measure should therefore carefully be applied, taking in consideration the low recolonisation rates of AMF as this can markedly effect the success of restoration.  相似文献   

Habitat selection and conservation of Sharpe's longclaw (Macronyx sharpei), a threatened Kenyan grassland endemic     

Muchane Muchai  Luc Lens  Leon Bennun 《Biological conservation》2002,105(3):271-277

Montane grassland is a severely threatened habitat in Kenya. Despite a high level of faunal endemism, it has received very little conservation attention. We investigated habitat selection in a threatened grassland endemic bird species, Sharpe's longclaw (Macronyx sharpei) (family Motacillidae), in order to understand its likely response to land-use changes. Between November 1995 and May 1996, we studied 41 territories of this species on the Kinangop Plateau in central Kenya. With an overall density of 0.4 birds ha⁻¹, longclaws lived in permanent groups of two to seven individuals. They were sedentary and territorial, with a mean home range size of 0.5 ha. The species avoided non-grassland areas entirely, and within grassland showed a strong preference for short grass with tussocks. Territory sizes and foraging ranges were smaller, and rates of pecking for food higher, in this grassland type than in open short grass or long grass. Land use changes, in particular conversion to cultivation or woodlots and ploughing up of grassland to remove tussocks, pose a serious and immediate threat to this species. Dairy farming is potentially compatible with grassland conservation, and conservation-friendly livestock rearing needs to be promoted through economic incentives, awareness-raising and technical advice.  相似文献   

What can be done to stop the decline?     

Lederman LM 《Science (New York, N.Y.)》2005,309(5731):51

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Enhancement of lutein production in Chlorella sorokiniana (Chorophyta) by improvement of culture conditions and random mutagenesis     

Cordero BF  Obraztsova I  Couso I  Leon R  Vargas MA  Rodriguez H 《Marine drugs》2011,9(9):1607-1624

Chlorella sorokiniana has been selected for lutein production, after a screening of thirteen species of microalgae, since it showed both a high content in this carotenoid and a high growth rate. The effects of several nutritional and environmental factors on cell growth and lutein accumulation have been studied. Maximal specific growth rate and lutein content were attained at 690 μmol photons m(-2) s(-1), 28 °C, 2 mM NaCl, 40 mM nitrate and under mixotrophic conditions. In general, optimal conditions for the growth of this strain also lead to maximal lutein productivity. High lutein yielding mutants of C. sorokiniana have been obtained by random mutagenesis, using N-methyl-N'-nitro-nitrosoguanidine (MNNG) as a mutagen and selecting mutants by their resistance to the inhibitors of the carotenogenic pathway nicotine and norflurazon. Among the mutants resistant to the herbicides, those exhibiting both high content in lutein and high growth rate were chosen. Several mutants exhibited higher contents in this carotenoid than the wild type, showing, in addition, either a similar or higher growth rate than the latter strain. The mutant MR-16 exhibited a 2.0-fold higher volumetric lutein content than that of the wild type, attaining values of 42.0 mg L(-1) and mutants DMR-5 and DMR-8 attained a lutein cellular content of 7.0 mg g(-1) dry weight. The high lutein yield exhibited by C. sorokiniana makes this microalga an excellent candidate for the production of this commercially interesting pigment.  相似文献   

Status of galaxiid fishes in Tasmania,Australia: conservation listings,threats and management issues     

Scott A. Hardie  Jean E. Jackson  Leon A. Barmuta  Robert W.G. White 《水产资源保护:海洋与淡水生态系统》2006,16(3):235-250

• 1. Fish of the family Galaxiidae are restricted to the southern hemisphere where they occupy a diverse array of habitats ranging from over 2000 m in elevation to sea level. Some species are diadromous and, hence, freshwater, estuarine and marine habitats are used during their life‐cycle; other species complete their entire life‐cycles in freshwater environments.
• 2. Tasmania has a diverse galaxiid fauna that accounts for 64% of native freshwater fish species found on the island. The Tasmanian galaxiid fauna is characterized by high species richness (5 genera and 16 species), endemism (11 species), restricted distributions, and non‐diadromous life histories (11 species).
• 3. The galaxiid fauna of Tasmania has significant conservation status with 69% of species considered ‘threatened’. The conservation status of the fauna is recognized at State, national and international levels.
• 4. The key threats to galaxiids in Tasmania are exotic species, hydrological manipulations, restricted distributions, general habitat degradation and exploitation of stocks.
• 5. Although work has recently been undertaken to conserve and manage Tasmanian galaxiid populations, the fauna is still thought to be imperilled. Knowledge gaps that need to be addressed include the biology and ecology of most species (e.g. reproductive biology, life histories, habitat use and requirements) and impacts of habitat manipulations, as well as mechanisms and impacts of interactions with exotic species. Techniques to monitor accurately the status of galaxiid species and their populations need to be developed and the coexistence of some galaxiids with introduced salmonids should also be examined.

Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Campylobacter fetus Bacteremia in a Healthy Patient Returning from a Trip to the Ecuadorian Amazonia          下载免费PDF全文

A. C. Chávez  S. Barrera  A. Leon  G. Trueba 《Zoonoses and public health》2017,64(5):391-393

Campylobacter fetus is an opportunistic pathogen which causes bacteremia and other invasive infections in immunocompromised patients who have been exposed to livestock or ingested animal products (uncooked meat or unpasteurized milk). The present report describes a C. fetus infection in a healthy adult (immunocompetent) who returned from a visit to the Ecuadorian Amazonia and who did not report exposure to the typical sources of infection.  相似文献