Genetic diversity at alkB locus in Brucella abortus     

Marianelli C  La Rosa G  Ciuchini F  Muscillo M  Pasquali P  Adone R 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2003,50(10):494-499

DNA polymorphism of the alkB gene, a DNA repair gene, was assessed by PCR on Brucella abortus biovars 1 (strains 99, S19, 45/20, RB51 and 2308), 3 (Tulya strain), 5 (B3196 strain) and 6 (870 strain). A DNA repetitive element, named IS711, was detected in all studied biovars 1 and its complete nucleotide sequence was determined. We found that the element in alkB gene, bounded by 14 bp imperfect inverted repeats (IRs), is 840 bp long and appears to duplicate a consensus target site, CTAG. Analysing its nucleotide sequence of both forward and reverse strands, more than 10 open reading frames (ORFs) were found. Two potential transposase coding regions were chosen comparing all possible ORFs with the database. Comparing IS711 elements isolated from Brucella species, including both those characterized in our work and the published ones, differences in length and in nucleotide composition were observed among Brucella species, members of the same species and within the same strain. Our results confirm the heterogeneity of IS711 elements in Brucella genus and suggest the possibility to use this element to assess gene and genome diversity and to identify new molecular markers for Brucella species.  相似文献   

Experimental Infection of Calves with Bovine Viral Diarrhoea Virus Type-2 (BVDV-2) Isolated from a Contaminated Vaccine     

Falcone E  Cordioli P  Tarantino M  Muscillo M  Sala G  La Rosa G  Archetti IL  Marianelli C  Lombardi G  Tollis M 《Veterinary research communications》2003,27(7):577-589

A non-cytopathic strain of BVDV-2 was isolated from a batch of live infectious bovine rhinotracheitis (IBR) vaccine, and inoculated intranasally into four 3-month-old calves. Severe signs of disease developed by days 4 and 6 in three of the calves, free of BVDV and antibodies to BVDV, that had been exposed to the virus. These calves survived the acute phase of the infection and progressively recovered. BVDV was consistently isolated, or the respective viral RNA was detected, in the buffy coats from blood samples collected starting from days 2 or 4 up to days 11 or 14 after the experimental infection. Viral RNA was also detected in sera from these infected calves until the presence in the serum of virus neutralizing antibodies was demonstrated. By contrast, the only calf having pre-existing neutralizing antibodies to BVDV at the start of the study was protected from the disease. No virus was detected at any time after experimental inoculation of this calf. Genomic characterization of the BVDV-2 isolated in cell cultures, or detected in sera from the experimentally infected animals, revealed 100% homology in the nucleotide sequence with the BVDV-2 detected as a contaminant of the live IBR virus vaccine. These findings provided evidence of the infective nature of the contaminant BVDV-2 and of its potential to generate disease outbreaks when inoculated into susceptible animals.  相似文献   

Interaction with avian cells and colonisation of specific pathogen free chicks by Shiga-toxin negative Escherichia coli O157:H7 (NCTC 12900)     

Best A  La Ragione RM  Cooley WA  O'Connor CD  Velge P  Woodward MJ 《Veterinary microbiology》2003,93(3):207-222

The prevalence of Escherichia coli O157:H7 infection in birds is low but several deliberate inoculation studies show that poultry are readily and persistently infected by this organism indicating a possible threat to public health. The mechanisms of colonisation of poultry are not understood and the aim is to establish models to study the interaction of E. coli O157:H7, at the cellular and whole animal levels. A non-toxigenic E. coli O157:H7 (NCTC 12900) was used in adherence assays with an avian epithelial cell line (Div-1) and used to inoculate 1-day-old SPF chicks. In vitro, NCTC 12900 induced micro-colonies associated with cytoskeletal arrangements and pedestal formation with intimate bacterial attachment. In the 1-day-old SPF chick, a dose of 1 x 10(5) cfu resulted in rapid and extensive colonisation of the gastrointestinal tract and transient colonisation of the liver and spleen. The number of E. coli O157:H7 organisms attained approximately 10(8) cfu/ml caecal homogenate 24h after inoculation and approximately 10(7) cfu/ml caecal homogenate was still present at day 92. Faecal shedding persisted for 169 days, ceasing 9 days after the birds came into lay and 6% of eggs were contaminated on the eggshell. Histological analysis of tissue samples from birds dosed with 1x10(7) cfu gave evidence for E. coli O157:H7 NCTC 12900 induced micro-colonies on the caecal mucosa, although evidence for attaching effacing lesions was equivocal. These models may be suitable to study those factors of E. coli O157:H7 that mediate persistent colonisation in avian species.  相似文献   

Polymerase chain reaction typing of genes of the locus of enterocyte effacement of ruminant attaching and effacing Escherichia coli          下载免费PDF全文

María Yuste  Jos A. Orden  Ricardo De La Fuente  Jos A. Ruiz-Santa-Quiteria  Dolores Cid  Susana Martínez-Pulgarín    Gustavo Domínguez-Bernal 《Canadian journal of veterinary research》2008,72(5):444-448

The variability of the tir, espA, and espD genes of the locus of enterocyte effacement (LEE) in 185 attaching and effacing Escherichia coli (AEEC) strains isolated from healthy and diarrheic cattle, sheep, and goats was investigated by polymerase chain reaction. Nineteen of the strains were enterohemorrhagic E. coli (EHEC); the other 166 were enteropathogenic E. coli (EPEC). The combinations of the tir and esp genes were associated with the variants of the eae gene but not with a strain’s belonging to the EPEC or EHEC group, animal species, or health status (healthy or diarrheic) of the animal. In addition, most of the strains showed the same combinations of LEE genes and serogroups as have been found in AEEC strains isolated from humans, which indicates that ruminants seem to be an EPEC reservoir for humans.  相似文献   

Physiologic responses and plasma endothelin-1 concentrations associated with abrupt cessation of nitric oxide inhalation in isoflurane-anesthetized horses     

Grubb TL  Högman M  Edner A  Frendin JH  Heinonen E  Malavasi LM  Frostell CG  Ryden A  Alving K  Nyman GC 《American journal of veterinary research》2008,69(3):423-430

OBJECTIVE: To assess physiologic responses and plasma endothelin (ET)-1 concentrations associated with abrupt cessation of nitric oxide (NO) inhalation in isoflurane-anesthetized horses. ANIMALS: 6 healthy adult Standardbreds. PROCEDURES: Horses were anesthetized with isoflurane in oxygen and placed in dorsal recumbency. Nitric oxide was pulsed into the respiratory tract for 2.5 hours, and then administration was abruptly discontinued. Just prior to commencement and at cessation of NO administration, and at intervals during a 30-minute period following cessation of NO inhalation, several variables including PaO(2), mean pulmonary artery pressure, venous admixture or pulmonary shunt fraction (Qs/Qt), and plasma ET-1 concentration were recorded or calculated. RESULTS: After cessation of NO inhalation, PaO(2) decreased slowly but significantly (172.7 +/- 29.8 mm Hg to 84.6 +/- 10.9 mm Hg) and Qs/Qt increased slowly but significantly (25 +/- 2% to 40 +/- 3%) over a 30-minute period. Mean pulmonary artery pressure increased slightly (14.0 +/- 1.3 mm Hg to 16.8 +/- 1 mm Hg) over the same time period. No change in serum ET-1 concentration was detected, and other variables did not change or underwent minor changes. CONCLUSIONS AND CLINICAL RELEVANCE: The improvement in arterial oxygenation during pulsed inhalation of NO to healthy isoflurane-anesthetized horses decreased only gradually during a 30-minute period following cessation of NO inhalation, and serum ET-1 concentration was not affected. Because a rapid rebound response did not develop, inhalation of NO might be clinically useful in the treatment of hypoxemia in healthy isoflurane-anesthetized horses.  相似文献   

Echinococcus ortleppi and E. granulosus G1, G2 and G3 genotypes in Italian bovines     

Casulli A  Manfredi MT  La Rosa G  Cerbo AR  Genchi C  Pozio E 《Veterinary parasitology》2008,155(1-2):168-172

To increase the knowledge on Echinococcus genotypes infesting cattle and water buffaloes (Bubalus bubalis) born and bred in Italy, the germinal layer of hydatid cysts was collected from the liver and the lungs of 80 animals slaughtered in 2007. Two mitochondrial genes (the cytochrome c oxidase subunit I and the NADH subunit I) were tested by PCR. Four genotypes were identified: G1 (sheep strain), G2 (Tasmanian sheep strain), G3 (buffalo strain), and G5 (cattle strain). Fertile cysts were detected only in the lungs of 4.5% of the total G1 lung cysts, of 9.4% of the total G3 lung cysts, and in the only G5 infected animal. This is the first report of Echinococcus ortleppi (genotype G5) in Italy.  相似文献   

THE USE OF BROMINE IN THE STERILIZATION OF FRUITS AND SEEDS     

La Rue CD 《Science (New York, N.Y.)》1937,85(2204):319-320

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Gestational Length and First Postpartum Ovulation of Criollo Mares on a Stud Farm in Southern Brazil     

G.H.Z. Winter  M.I.B. Rubin  F.D. De La Corte  C.A.M. Silva 《Journal of Equine Veterinary Science》2007,27(12):531-534

The Criollo horse industry requires more efforts toward a better understanding of breed characteristics and physiology; few studies have been conducted in Criollo horses to fulfill this demand. Toward this aim, 70 Criollo mares (between 3 and 28 years of age) underwent physiologic evaluation of the length of gestation, occurrence of foal heat, and interval to postpartum ovulation. Gestation length in the 70 mares was 335.6 ± 10.5 days, varying from 312 to 364 days. The mean (±SD) interval from parturition to first ovulation of 42 mares that foaled between September and December of 2005 and 2006 was 19.9 ± 14.0 days. Eighty-three percent of the mares had an interval to foal heat ovulation shorter than 20 days (35/42). The mean (±SD) parturition to ovulation interval of these mares was 14.2 ± 3.0 days.  相似文献   

Identification of sylvatic Trichinella (T3) in foxes from France.     

G La Rosa  E Pozio  J Barrat  J Blancou 《Veterinary parasitology》1991,40(1-2):113-117

Thirty-three foxes (Vulpes vulpes) from a sample of 1912 collected in France were found to be infected with Trichinella spp. Four isolates were obtained for genetic identification. Isoenzymatic and biological analysis of these isolates revealed the presence of two distinct genetic types of Trichinella, Trichinella spiralis s.str. (T1) and Trichinella sp. (T3) (Trichinella nelsoni according to Soviet authors) in the fox population. The reproductive capacity index of these isolates in Wistar rats was high for T. spiralis and low for T3. This is the first report of T3 type from wild animals in France. The epidemiological implications are discussed.  相似文献   

Solar input and energy storage in a five-year-old American sycamore plantation     

Gerald A. Tuskan  Armando A. De La Cruz 《Forest Ecology and Management》1982,4(2):191-198

Energy stored in a 5-year-old American sycamore plantation grown in Mississippi was determined by bomb calorimetry of component parts of selected trees randomly sampled in autumn and spring. The results indicated significant differences among tree components. The caloric values were 4675.81 cal g^?1 for leaves, 4631.76 cal g^?1 for branch bark, 4489.12 cal g^?1 for branch wood, 4753.85 cal g^?1 for stem bark, and 4488.76 cal g^?1 for stem wood. Based on these caloric values, the total energy yeild for a 1-ha plantation, containing 1200 trees with a total above-ground biomass of 20.3 t, was computed at 9.22 × 10¹⁰ calories. The storage efficiency of the forest stand, which was calculated by dividing total energy yields by available photosynthetic solar radiation received during the growing season (168,462 × 10⁸ cal), was 0.55%. The biomass yield of this 5-year-old sycamore plantation is sufficient to supply the electrical energy needs of an average household for nearly 3 years.  相似文献