Prevalence of antibody to caprine arthritis-encephalitis virus in goats in the United States.

Goats from 28 states were tested for antibodies to caprine arthritis-encephalitis virus. Of 3,790 goats, 1,175 (31%) tested positive, and of 196 herds tested, 143 (73%) had 1 or more seropositive members. This prevalence, based on serum samples from all goats in the participating herds, was lower than most rates reported in other studies. Such studies were based on fewer samples, incomplete sampling of herds, or smaller geographic base. Prevalence was highest in western Pacific and northern plains regions, increased with age to 3 years, was highest among goats on family-owned farms, and was lowest in the Angora breed. Differences in prevalence was not related to gender or size of herd.     

The re-emergence of indigenous forest in an urban environment, Christchurch, New Zealand

Christchurch, the second largest city in New Zealand is a planned city on a coastal plain on the east coast of the South Island. The birth of the city and the subsequent century of development was characterised by colonial values and tree and garden planting with familiar European species along with those from Australia, North America, and eventually all other continents. The image of an “English garden city” with classical parks of oaks and willow-lined rivers became the accepted norm and the way in which the city has been promoted to potential tourists. Gardening is one of the top two recreational activities and exotic species greatly outnumber native species in the flora and in gardens. This has had serious consequences for the highly fragmented and degraded indigenous vegetation and its co-adapted wildlife. A few hardy indigenous species continued to regenerate through this period, but since the 1970s, there has been a progressive change of attitude and interest in reclaiming the natural heritage of the city, manifest in widespread private and public planting of indigenous species and active habitat restoration. In this article we examine the indigenous and exotic shrub and tree components of the Christchurch flora as planted street trees, in domestic gardens, and in parks. We also present data on shrub and tree regeneration in parks and domestic gardens in the city. Indications are that the more sensitive, less intrusive management of urban environments, combined with the greater density of indigenous seed sources, has allowed regeneration of a wide range of indigenous species across a broad spectrum of habitats – from neglected gardens to pavement cracks to exotic plantations. This is despite the competition from the prodigious seed banks and density of exotic trees, shrubs, and ground covers and albeit minimal impacts of introduced browsing and seed eating mammals. If the present trends continue through appropriate management and facilitation, these tentative signs of native forest regeneration should eventually proliferate into a sustainable mixed origin urban forest that resurrects and preserves the natural character of the region.     

Preliminary results of an anticircumsporozoite DNA vaccine trial for protection against avian malaria in captive African black-footed penguins (Spheniscus demersus).

Captive juvenile African black-footed penguins (Spheniscus demersus) housed in an outdoor enclosure at the Baltimore Zoo have an average 50% mortality from avian malarial (Plasmodium sp.) infection each year without intense monitoring for disease and chemotherapeutic intervention. During the 1996 malaria transmission season, the safety and efficacy of an anti-circumsporozoite (CSP) DNA vaccine encoding the Plasmodium gallinaceum CSP protein against P. relictum were studied. The goal was to reduce clinical disease and death without initiating sterile immunity after release into an area with stable, endemic avian malaria. The birds were monitored for adverse clinical signs associated with vaccination, the stimulation of an anti-CSP antibody response, and protection afforded by the vaccine. The presence of P. relictum in trapped culicine mosquitoes within the penguin enclosure was monitored to assess parasite pressure. Among the vaccinated penguins, the parasitemia rate dropped from approximately 50% to approximately 17% despite intense parasite pressure, as determined by mosquito infection rate. During the year of the vaccine trial, no mortalities due to malaria occurred and no undesirable vaccination side effects occurred. This is the first trial of an antimalarial vaccine in a captive penguin colony.     

Characterization of multidrug resistant Salmonella recovered from diseased animals

Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one antimicrobial, and 265 (70%) to three or more antimicrobials. Resistance was most often observed to tetracycline (78%), followed by streptomycin (73%), sulfamethoxazole (68%), and ampicillin (54%), and to a lesser extent chloramphenicol (37%), kanamycin (37%), amoxicillin-clavulanic acid (20%), and ceftiofur (17%). With regards to animal of origin, swine Salmonella isolates displayed the highest rate of resistance, being resistant to at least one antimicrobial (92%), followed by those recovered from turkey (91%), cattle (77%), chicken (68%), and equine (20%). Serovars commonly showing multidrug resistance (MDR) to > or =9 antimicrobials were S. Uganda (100%), S. Agona (79%), and S. Newport (62%), compared to S. Heidelberg (11%) and S. Typhimurium (7%). Class-1 integrons were detected in 43% of all isolates, and were found to contain aadA, aadB, dhfr, cmlA and sat1 gene cassettes alone or in various combinations. All ceftiofur resistant isolates (n=66) carried the bla(CMY) beta-lactamase gene. A total of 230 PFGE patterns were generated among the 380 isolates tested using XbaI, indicating extensive genetic diversity across recovered Salmonella serovars, however, several MDR clones were repeatedly recovered from different diseased animals.     

Isolation and characterisation of biologically-active compounds from some plant extracts

Of the numerous fractions obtained from the crude plant extracts of Chenopodium ambrosioides, Conyza dioscordisis and Convolvulus arvensis, 11 were found to be active against stored grain pests. The chemical structures of compounds present in the 11 fractions were found by gas chromatography/mass spectrometry to include predominantly long-chain fatty acid esters of hexadecanoic, arachidonic, and octadecanoic acids.     

Some fluorine-containing pheromone analogues

Two analogues of the aphid alarm pheromone (E)-β-farnesene, a trifluorofarnesene and a difluoro-1-norfarnesene, were found to be highly active and were more readily detectable than the parent compound. For (Z)-hexadec-11-enal, a component of some lepidopteran sex attractant pheromones, replacement of the carbonyl oxygen with a difluoromethyl group to give a difluoroheptadecadiene resulted in loss of activity. A trifluoroacetoxyhexadecanolide was a more volatile analogue of the mosquito oviposition pheromone (?)-(5R,6S)-6-acetoxy-5-hexadecanolide and was highly active.     

Metal chelate molluscicides: The redistribution of iron diazaalkanolates from the gut lumen of the slug,Deroceras reticulatum (Müller) (Pulmonata: Limacidae)

Two related iron chelates, one toxic to slugs by ingestion, the other not, were introduced into the foregut of D. reticulatum. The subsequent movement and redistribution of the metal within the slug tissues was studied by labelling the chelates with the radioactive isotope ⁵⁵Fe. In slugs which survived treatment approximately half of the ⁵⁵Fe was voided in faeces. The iron retained became unevenly distributed, the highest concentration occurring in the digestive gland, irrespective of the chelate used. At high doses, slugs treated with tris(1-oxo-1,2-diazabutan-2-oxido)Fe(III) were fatally poisoned while those treated with the homologue, tris(1-oxo-1,2-diazaoctan-2-oxido)Fe(III) were not. Slugs killed by the toxic chelate consistently contained proportionally less iron in the digestive gland and proportionally more in the body wall and reproductive system. Dosing slugs already killed by carbon dioxide asphyxiation gave a similar pattern, suggesting that the greater mobility of the iron from the toxic chelate was not a function of the slugs' metabolism.     

The effect of rectal temperature on perianesthetic serum concentrations of transdermally administered fentanyl in cats anesthetized with isoflurane

OBJECTIVES: To determine whether moderate hypothermia during 4 hours of anesthesia with isoflurane substantially affects serum concentrations of transdermally administered fentanyl in the perianesthetic period in cats. ANIMALS: 7 healthy mature cats. PROCEDURE: A fentanyl patch (25 microg/h) was applied to the shaved thorax 24 hours before induction of anesthesia. Anesthesia was induced at time 0. Each cat received 2 treatments in a random order. Treatments were isoflurane anesthesia with normothermia and isoflurane anesthesia with hypothermia. Cats were intubated, connected to a nonrebreathing circuit, and maintained at 1.3X minimum alveolar concentration for 4 hours. Cats in the hypothermia treatment groups were actively cooled to 35 degrees C following the induction of anesthesia. Serum fentanyl analysis was performed at -24, -12, 0, 1, 2, 3, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, and 24 hours. RESULTS: Mean +/- SEM serum fentanyl concentration (SFC) for the hypothermia treatment group (0.598 +/- 0.3048 ng/mL) was significantly lower than the baseline concentration (1.834 +/- 0.6393 ng/mL) at 1 hour. This significant reduction persisted for the duration of anesthesia for the hypothermia treatment group. Serum fentanyl concentrations returned to baseline values within 1 hour of the end of anesthesia, regardless of body temperature. CONCLUSIONS AND CLINICAL RELEVANCE: Hypothermia during inhalant anesthesia induced a significant reduction in SFC obtained with transdermal administration. The impact of this reduction in SFC on the contribution of transdermally administered fentanyl to any reduction in the need for inhalant anesthesia remains to be determined.     

Prevalence of cpb2, encoding beta2 toxin,in Clostridium perfringens field isolates: correlation of genotype with phenotype

Beta2 toxin, encoded by the cpb2 gene, has been implicated in the pathogenesis of porcine, equine and bovine enteritis by type A Clostridium perfringens. By incorporating primers to cpb2 into a multiplex genotyping PCR, we screened 3270 field isolates of C. perfringens. Of these, 37.2% were PCR positive for the cpb2 gene. The majority of isolates from cases of porcine enteritis were positive for cpb2 (>85%), and this was even more true for C. perfringens isolated from cases of porcine neonatal enteritis (91.8%). In contrast, isolates from normal pigs only contained cpb2 in 11.1% of cases. The correlation between enteritis in other animal species and the presence of cpb2 was not so strong. cpb2 was found in 21.4% of C. perfringens isolates from cattle with enteritis, and in 47.3% of isolates from calves with enteritis or abomastitis. The prevalence of cpb2 varied with genotype, with type A isolates being positive for this gene in 35.1% of cases. Furthermore, enterotoxigenic type D or type E strains almost always carried cpb2. We cloned a 6xHIS-tagged beta2 (HIS-beta2) and used this protein to raise antiserum against beta2. Culture supernatants from 68 cpb2-positive and 13 cpb2-negative strains were tested for the presence of beta2 by Western blotting. In cpb2-positive isolates of porcine origin, beta2 was almost always detected (96.9%). However, in cpb2-positive isolates from other animal species, only 50.0% expressed beta2 protein. The high rate of cpb2-positivity among strains from neonatal pigs with enteritis and the high correlation of genotype with phenotype, supports the contention that beta2 toxin plays a role in the pathogenesis of these infections. However, it may be important to consider the use of an additional method for the detection of beta2 toxin in non-porcine cpb2-positive isolates when making claims about the role of beta2 in enteritis in non-porcine species.