Farm management factors associated with bulk tank total bacterial count in Irish dairy herds during 2006/07

Research has shown that total bacterial count (TBC), which is the bacterial growth per ml of milk over a fixed period of time, can be decreased by good hygiene and farm management practices. The objective of the current study was to quantify the associations between herd management factors and bulk tank TBC in Irish spring calving, grass-based dairy herds. The relationship between bulk tank TBC and farm management and infrastructure was examined using data from 400 randomly selected Irish dairy farms where the basal diet was grazed grass. Herd management factors associated with bulk tank TBC were identified using linear models with herd annual total bacterial score (i.e., arithmetic mean of the natural logarithm of bulk tank TBC) included as the dependent variable. All herd management factors were individually analysed in a separate regression model, that included an adjustment for geographical location of the farm. A multiple stepwise regression model was subsequently developed. Median bulk tank TBC for the sample herds was 18,483 cells/ml ranging from 10,441 to 130,458 cells/ml. Results from the multivariate analysis indicated that the following management practices were associated with low TBC; use of heated water in the milking parlour; participation in a milk recording scheme; and tail clipping of cows at a frequency greater than once per year. Increased level of hygiene of the parlour and cubicles were also associated with lower TBC. Herd management factors associated with bulk tank TBC in Irish grazing herds were generally in agreement with most previous studies from confinement systems of milk production.     

Low dietary inorganic phosphate affects the lung growth of developing mice

Inorganic phosphate (Pi) plays a critical role in diverse cellular functions, and regulating the Pi balance is accomplished by sodium-dependent Pi co-transporter (NPT). Pulmonary NPT has recently been identified in mammalian lungs. However, to date, many of the studies that have involved Pi have mainly focused on its effect on bone and kidney. Therefore, current study was performed to discover the potential effects of low Pi on the lung of developing transgenic mice expressing the renilla/firefly luciferase dual reporter gene. Two-weeks old male mice divided into 2 groups and these groups were fed either a low PI diet or a normal control diet (normal: 0.5% Pi, low: 0.1% Pi) for 4 weeks. After 4 weeks of the diet, all the mice were sacrificed. Their lungs were harvested and analyzed by performing luciferase assay, Western blotting, kinase assay and immunohistochemistry. Our results demonstrate that low Pi affects the lungs of developing mice by disturbing protein translation, the cell cycle and the expression of fibroblast growth factor-2. These results suggest that optimally regulating Pi consumption may be important to maintain health.     

Spiroplasma citri Movement into the Intestines and Salivary Glands of Its Leafhopper Vector, Circulifer tenellus

ABSTRACT Spiroplasma citri, a helical, wall-less prokaryote in the class Molli-cutes, is transmitted by the beet leafhopper, Circulifer tenellus. Invasion of leafhopper tissues and cytopathological effects by S. citri were investigated by transmission electron microscopy. All eight cell types of the principle salivary glands, as well as the adjacent muscle cells and the cells of the accessory salivary glands, were colonized by the spiroplas-mas. In both midgut epithelia and salivary gland cells, spiroplasmas usually occurred in membrane-bound cytoplasmic vesicles that often were located near the cell periphery. In several salivary gland cells, spiroplas-mas were also observed within membranous pockets apparently formed by invagination of the plasmalemma beneath intact basal lamina. These observations are consistent with spiroplasma entry into the insect cells by receptor-mediated endocytosis. Cytopathological effects of spiroplasma infection in salivary cells included loss of membrane and basal lamina integrity, presence in some cells of irregular inclusion-like structures containing dense matrices of filamentous material that labeled with anti S. citri antibodies, and apparent disorganization of the endoplasmic reticulum. Compared to the tightly aligned fiber bundles in healthy muscle cells, bundles in spiroplasma-containing muscle cells appeared fragmented and loosely arranged. Such symptoms could contribute to the reduction in longevity and fecundity that has been previously reported for S. citri-infected C. tenellus.     

An outbreak of highly pathogenic avian influenza subtype H5N1 in broiler breeders, Korea

Highly pathogenic avian influenza (HPAI) was diagnosed in broiler breeders, submitted to the National Veterinary Research and Quarantine Service in South Korea. Grossly, the dead breeders had lesions consistent with HPAI, including pancreatic mottling, splenomegaly, pulmonary edema and congestion, and hemorrhages in the mucosa of the proventriculus, gizzard and small intestine, and on the serosal surface. Microscopically, there were necrotized hepatitis and pancreatitis, lymphocytic meningoencephalitis, myocarditis, and interstitial pneumonia. Influenza viral antigen was demonstrated in areas closely associated with histopathologic lesions. The AI virus was isolated from cecal tonsils, feces, trachea, and kidney of the chickens. The isolated virus was identified as the highly pathogenic H5N1, with a hemagglutinin proteolytic cleavage site deduced amino acid sequences of QREKRKKR/GLFGAGLFGAIAG. In order to determine the pathogenicity of the isolate, eight 6-week-old specific pathogen free chickens were inoculated intravenously with the virus, and all the birds died within 24 hr after inoculation. This is the first report of an outbreak of HPAI in the chickens in South Korea.     

Protective effects of bio-active ceramic water on alcohol-induced hepatic injury in pigs

Among many detrimental injuries, alcohol is implicated in hepatitis, fatty liver, hepatic fibrosis, and cirrhosis. The purpose of this study was to evaluate the protective effect of bio-active ceramic water on alcohol-induced hepatic injury in pigs. Twelve male Landrace pigs were divided into 3 groups. Groups 1, 2, and 3 were fed with bio-active ceramic water + normal liquid diet, bio-active ceramic water + liquid diet containing 15% ethanol, and tap water + liquid diet containing 15% ethanol for 12 weeks, respectively. For serological, histopathological, and immunohistochemical analysis, all pigs were sacrificed at week 12. In group 3, serum ALT and AST levels increased, and mild fatty change and moderate necrosis were detected in the liver. Collagen fibers, myofibroblasts, and CYP2E1 were also increased or activated in group 3. In group 2, there were mild hepatic injuries compared to group 3. However, injuries and activations were not observed in the liver in group 1. We suggest that the bio-active ceramic water used in the present study had protective capability against ethanol-induced hepatic injury and that having no toxic effect on the pig liver. The bio-active ceramic water might be useful as a therapeutic drinking water in patients suffering from alcoholic liver diseases.     

Outbreak of Fowl cholera in Baikal teals in Korea

Fowl cholera (FC) caused by Pasteurella multocida was diagnosed in waterfowl, Baikal teals (Anas formosa), submitted to the National Veterinary Research and Quarantine in Korea. The total number of mortalities was 13,228 out of approximately 100,000 birds that wintered in Cheonsoo Bay, the most important habitat area of Baikal teals in the world. Clinical signs were detected in only a few birds because of sudden death. Grossly, the dead Baikal teals had lesions consistent with FC, including multifocal necrotic foci in the liver with enlargement, petechial or ecchymotic hemorrhages on the heart, and mucoid exudates in the duodenal mucosa. Microscopically, there were hepatocytic necrosis with bacterial colonization, hemorrhage and necrosis in the myocardium, and hemorrhagic enteritis. Pasteurella multocida was isolated from the liver and the heart of all birds examined, and the isolate (P-627) was the serotype 1 X 12 X 13 by the agar gel immunodiffusion test. In order to estimate the virulence of P-627, 5-wk-old commercial ducks were exposed intramuscularly or intratracheally to the bacterium. On the basis of mortality rate, the isolate, P-627, was found to be highly virulent. This is the first report of an outbreak of FC in Baikal teals in Korea.     

Distribution of nociceptin-like immunoreactivity in the central nervous system of the Mongolian gerbil: an immunohistochemical study

This study is designed to demonstrate the distribution of nociceptin, endogenous ORL1 receptor ligand, in the central nervous system of the Mongolian gerbil. To intensify the nociceptin-like immunoreactivity (NOC-LI), colchicine was administered into the lateral ventricle, at 48 h prior to the transcardiac perfusion. In the group without colchicine treatment, NOC-LI was observed in the fibres of the spinal dorsal horn, specifically in the superficial layers. However, the NOC-LI in the superficial layers disappeared after the administration of colchicine. In the brain, NOC-LI was prominent in the hypothalamus, hippocampus, cerebral peduncle, substantia nigra, dorsal raphe, periaqueductal grey, locus coeruleus and trapezoid nucleus. Colchicine treatment markedly intensified the NOC-LI in the somata of the central nervous system, whereas the untreated sections were too weak to observe and analyse. The distribution of NOC-LI provides informative data for studies of the neuronal circuit that nociceptin may be involved in.     

PCR-based specific and sensitive detection of Pectobacterium carotovorum ssp. carotovorum by primers generated from a URP-PCR fingerprinting-derived polymorphic band

A 24-mer primer pair was generated by sequencing a URP-PCR fingerprinting-derived polymorphic band that is uniquely shared in Pectobacterium carotovorum ssp . carotovorum strains (Pcc). The primer set (EXPCCF/EXPCCR) amplified a single band of expected size (0·55 kb) from genomic DNA obtained from 29 Pcc strains and three Pectobacterium carotovorum ssp. wasabiae (Pcw) strains, but not from other P. carotovorum subspecies atrosepticum , betavasculorum or odoriferum , or from other Erwinia spp. or bacterial genera. The Rsa I digestion profile of the amplified bands divided Pcc strains into five groups with a unique profile from Pcw strains. First-round PCR detected between 5 × 10² and 1 × 10³ colony forming units (CFU) mL⁻¹ and detection sensitivity was increased to as few as 2–4 CFU mL⁻¹ after second-round (nested) PCR. This PCR protocol was used directly to detect Pcc strains in infected plant tissues.