Role of litter in the transmission of Campylobacter jejuni

Autoclaved or non-autoclaved used broiler litter that was experimentally contaminated with Campylobacter jejuni was capable of infecting specific-pathogen-free chicks maintained in modified Horsfall isolators. Artificially infected chicks became fecal shedders of C. jejuni, resulting in contamination of both autoclaved and non-autoclaved used broiler litter. Fecal shedding of C. jejuni by litter-reared, artificially infected chicks persisted for at least 63 days after chicks were transferred to an isolation unit with a wire floor, which prevented coprophagy. C. jejuni was consistently recovered from water and litter in units housing directly and indirectly infected birds, indicating environmental contamination. These experiments demonstrate the potential role of litter in the perpetuation and transmission of C. jejuni infection in commercial chickens.     

Typhlocolitis associated with <Emphasis Type="Italic">Clostridium difficile</Emphasis> ribotypes 078 and 110 in neonatal piglets from a commercial Irish pig herd

Background

Clostridium difficile is a recognised cause of typhlocolitis and diarrhoea in neonatal pigs but has never been confirmed in association with pathology and disease in Irish pigs.

Case Presentation

Four neonatal piglets, with a history of diarrhoea were referred to the Central Veterinary Research Laboratory, Backweston for necropsy. They were from a fully integrated, commercial pig farm with approximately 1000 sows. Three piglets had acute, superficial, erosive and suppurative typhlocolitis and the other had mild suppurative mesocolitis. Clostridium difficile (C. difficile) toxins A/B were detected using ELISA in the colonic contents from each piglet. C. difficile isolates from two of the piglets were PCR-ribotyped as 078 and an isolate from a third pig was ribotyped as 110.

Conclusions

This is the first report confirming C. difficile in association with typhlocolitis in Irish pigs.

     

Comparative Development of Embryonic Age by Organogenesis in Domestic Dogs and Cats

The precise determination of the embryonic chronology is very important in reproductive biotechnologies, especially in estimating embryonic age. Thus, there is a need for greater knowledge and standardization for determining the chronology of embryonic development and functional morphology. We describe aspects of embryonic development in two domestic carnivores to add knowledge about organ peculiarities and for application in veterinary practice, in prenatal development and in the biotechnology fields. We found that the development of differential characteristics of embryonic organs occurs in the first trimester of pregnancy for both species. Thus, using the combination of the crown‐rump length, macroscopic analysis and optical microscopy, it is possible to predict gestational age more precisely in animals that lack a defined breed and establish an embryonic pattern.     

Forces for morphogenesis investigated with laser microsurgery and quantitative modeling

We investigated the forces that connect the genetic program of development to morphogenesis in Drosophila. We focused on dorsal closure, a powerful model system for development and wound healing. We found that the bulk of progress toward closure is driven by contractility in supracellular "purse strings" and in the amnioserosa, whereas adhesion-mediated zipping coordinates the forces produced by the purse strings and is essential only for the end stages. We applied quantitative modeling to show that these forces, generated in distinct cells, are coordinated in space and synchronized in time. Modeling of wild-type and mutant phenotypes is predictive; although closure in myospheroid mutants ultimately fails when the cell sheets rip themselves apart, our analysis indicates that beta(PS) integrin has an earlier, important role in zipping.     

Massive CO₂ ice deposits sequestered in the south polar layered deposits of Mars

Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO(2)) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO(2) volatile release. If released into the atmosphere at times of high obliquity, the CO(2) reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling.     

Post-harvest applications of zoxamide and phosphite for control of potato tuber rots caused by oomycetes at harvest

Potato storage tuber rots caused by the late blight and pink rot pathogens at harvest can cause severe economic losses, warranting the need for effective post-harvest fungicide applications. The purpose of this study was to evaluate the efficacy of select post-harvest fungicides in reducing tuber infections by the late blight and pink rot pathogens when applied at various post-inoculation time intervals. ‘Russet Burbank’ potatoes were inoculated by submersion in an aqueous suspension ofPhytophthora infestans orPhytophthora erythroseptica zoospores at 0, 1, 2, 4, and 6 h prior to receiving a post-harvest treatment. Products evaluated were zoxamide (various rates and formulation), phosphite (335 g a.i./MT), and a hydrogen peroxide/peroxyacetic acid mixture (HPPA, 9 g a.i./MT), all applied at 2.08 L/MT of tubers as a low pressure spray prior to storage. Zoxamide and phosphite significantly reduced late blight and pink rot incidence and severity when applied immediately after inoculation. HPPA was less effective at controlling disease development. Phosphite was effective at reducing late blight development at all time intervals up to 6 h post-inoculation (7% vs 80% in untreated). Zoxamide appeared to have good post-harvest disease control if applied soon after inoculation. The maximum time intervals between inoculation and treatment where significant reductions in pink rot incidence were observed was 0 h for HPPA (28%), 2 h for zoxamide (55%; 64 g a.i./MT) and 6 h for phosphite (13%) compared to the untreated (73%). Phosphite provided consistent disease control even when applied several h after inoculation and has potential to be a reliable post-harvest fungicide for the potato industry.     

Hot water extractable phosphorus pools as indicators of soil P responses to harvest residue management in an exotic pine plantation of subtropical Australia

Purpose

This study evaluated the potential of using hot water extractable phosphorus (P) pools as a method to assess the impacts of harvest residue management on the bioavailability of P in an exotic pine plantation of southeast Queensland, Australia.

Materials and methods

This study was carried out under three harvest residue management regimes: (1) residue removal, RR₀; (2) single-level residue retention (operational level), RR₁; and (3) double level of residue retention, RR₂, established immediately following clear-cut harvesting in a randomised complete block experiment. Soil was sampled after 24 months of the residue management regimes applied and analysed for hot water extractable inorganic P (HWEIP), hot water extractable organic P (HWEOP) and total P (HWETP), in relation to hot water extractable organic C (HWEOC) and N (HWEON), calcium chloride extractable P (CaCl₂_P), bicarbonate extractable P (NaHCO₃_P) and fluoride extractable P (Bray1_P).

Results and discussion

The HWEIP and CaCl₂_P concentrations showed no significant variations amongst the treatments, while Bray1_P, NaHCO₃_P and the HWEOP P pools were only significantly greater in the RR₂ treatment than the RR₀ treatment. In contrast, the HWETP pool showed highly significant (p?<?0.005) differences amongst all the treatments. In addition, both the HWEOP and HWETP were significantly related to the HWEOC and the total C, in contrast to the lack of such relationships with soil total P, suggesting their association with the HWEOC released through residue decomposition.

Conclusions

This study showed that HWETP is a more sensitive measure of labile soil P and has the potential to be used as an indicator of management practices, particularly in cases where high spatial variations in soil P concentrations might confound P responses.