Effects of bacterial coinfection on the pathogenesis of avian pneumovirus infection in turkeys     

Jirjis FF  Noll SL  Halvorson DA  Nagaraja KV  Martin F  Shaw DP 《Avian diseases》2004,48(1):34-49

Four- and nine-week-old poults were inoculated with cell culture propagated avian pneumovirus (APV) into each conjunctival space and nostril, followed by inoculation 3 days later with Escherichia coli, Bordetella avium (BA), or Ornithobacterium rhinotracheale or a mixture of all three (EBO). Clinical signs were evaluated on days 3, 5, 7, 9, 11, and 14 postinoculation (PI) of APV. The poults were euthanatized on days 2, 4, 6, 10, and 14 PI, and blood and tissues were collected. The poults that received APV followed by EBO or BA alone developed more severe clinical signs related to nasal discharge and swelling of intraorbital sinuses than did poults inoculated with APV alone or bacteria alone. More severe pathologic changes were found in poults inoculated with APV+BA that extended to the air sacs and lungs, particularly in 9-wk-old poults. Bordetella avium was recovered from tracheas and lungs of birds that were inoculated with APV followed by EBO or BA alone. APV was detected by immunohistochemical staining in the upper respiratory tract longer in the groups of poults inoculated with APV and pathogenic bacteria than in those that received only APV, particularly when BA was involved. Viral antigen was also detected in the lungs of poults that were inoculated with APV followed by administration of EBO or BA alone. Loss of cilia on the epithelial surface of the upper respiratory tract was associated with BA infection and may enhance infection with APV, allowing deeper penetration of the virus into the respiratory tract.  相似文献   

Avian pneumovirus and its survival in poultry litter     

Velayudhan BT  Lopes VC  Noll SL  Halvorson DA  Nagaraja KV 《Avian diseases》2003,47(3):764-768

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Antigenic cross-reactivity among avian pneumoviruses of subgroups A,B, and C at the matrix but not nucleocapsid proteins     

Lwamba HC  Halvorson DA  Nagaraja KV  Turpin EA  Swayne D  Seal BS  Njenga MK 《Avian diseases》2002,46(3):725-729

Earlier findings from our laboratory based on analysis of nucleotide and predicted amino acid sequence identities of 15 avian pneumoviruses (APVs) isolated from the United States (subgroup C) demonstrated that the viruses were phylogenetically separated from the European subgroup A and subgroup B viruses. Here, we investigated whether viruses from the three subgroups were cross-reactive by testing field sera positive for each of the APV subgroups in an enzyme-linked immunosorbent assay (ELISA) test with recombinant matrix (M) and nucleoprotein (N) proteins generated from a Minnesota APV isolate (APV/MN2A). Sera from turkeys infected with APV subgroup A, B, or C reacted with recombinant M protein derived from APV/MN2A. In contrast, recombinant N protein from APV/MN2A virus was reactive with sera from subtypes A and C viruses but not from subtype B virus. The results illustrate that viruses from the three APV subtypes share antigenic homology, and the M protein-based ELISA is adequate for monitoring APV outbreaks but not for distinguishing between different subtypes.  相似文献   

Preliminary observations on the pharmacokinetics of CDRI compound 81/470 in calves     

Nagaraja  N.V.  Singh  S.K.  Jain  G.K.  Singh  S.  Gupta  R.C. 《Veterinary research communications》1998,22(1):67-72

Veterinary Research Communications -  相似文献   

Secretory antibodies against turkey coronaviral enteritis.     

K V Nagaraja  B S Pomeroy 《American journal of veterinary research》1978,39(9):1463-1465

Studies on local immunity to transmissible coronaviral enteritis of turkeys (bluecomb) was made. Intestinal secretions and bile from affected birds contained secretory immunoglobulins against coronaviral antigen throughout the 6 months' duration of the experiment. Attempts to purify and to characterize the globulins in intestinal secretions and bile of the affected birds were made, using the techniques of gel filtration, DEAE chromatography, and immunoelectrophoresis. Class-specific anti-turkey IgA antiserum in the agar gel precipitin test further established the presence of IgA in the intestinal secretions and bile.  相似文献   

Iron acquisition by Ornithobacterium rhinotracheale     

Tabatabai LB  Zehr ES  Zimmerli MK  Nagaraja KV 《Avian diseases》2008,52(3):419-425

Ornithobacterium rhinotracheale (ORT) is an emerging respiratory pathogen of poultry in North America that is causing millions of dollars in economic losses to the poultry industry. Ornithobacterium rhinotracheale is associated with airsacculitis, pleuritis, pneumonia, and consolidation of lungs. Little is known about the molecular mechanisms of infection. In this study, the mechanism of iron acquisition by O. rhinotracheale was explored. O. rhinotracheale strains grown under iron deprivation in media containing 200 microM 2,2'-dipyridyl did not secrete siderophores as measured by the chrome azurol S (CAS) agar and CAS solution assays. Filter disks impregnated with various protein-bound iron compounds and inorganic iron salts of Fe(III) and Fe(II) placed on iron-restricted agar inoculated with a lawn of O. rhinotracheale supported growth from sheep and porcine hemoglobins, ovotransferrin, Fe(III), and Fe(II), but they did not support growth from bovine transferrin, bovine apo-transferrin, bovine lactoferrin, and hemin. However, both bovine hemoglobin and transferrin supported growth of O. rhinotracheale serotype C. Four immunoreactive proteins involved in iron acquisition were identified in an O. rhinotracheale membrane extract by using mass spectrometry. Furthermore, O. rhinotracheale field strains showed differential sensitivity to 2,2'-dipyridyl. Of the 72 field strains tested, 22 strains were resistant to the iron chelator at concentrations of 50 microM and 100 microM, suggesting this attribute may be related to disease-producing potential of these strains. This is the first report on the identification of the iron acquisition mechanism of O. rhinotracheale.  相似文献   

Effects of supplemental fat source on nutrient digestion and ruminal fermentation in steers     

Montgomery SP  Drouillard JS  Nagaraja TG  Titgemeyer EC  Sindt JJ 《Journal of animal science》2008,86(3):640-650

Five Holstein steers (235 kg of BW) fitted with ruminal, duodenal, and ileal cannulas were used in a 5 x 5 Latin square design experiment to determine the effects of supplemental fat source on site and extent of nutrient digestion and ruminal fermentation. Treatments were diets based on steam-flaked corn containing no supplemental fat (control) or 4% (DM basis) supplemental fat as tallow, dried full-fat corn germ (corn germ), corn oil, or flax oil. Fat supplementation decreased (P < 0.08) ruminal starch digestion but increased (P < 0.03) small intestinal starch digestion as a percentage of intake. Feeding corn germ decreased (P < 0.09) ruminal starch digestion and increased (P < 0.03) large intestinal starch digestion compared with steers fed corn oil. Large intestinal starch digestion was less (P < 0.04), and ruminal NDF digestion was greater (P < 0.09) for steers fed tallow compared with steers fed other fat sources. Small intestinal (P < 0.08) and total tract NDF digestibilities were greater (P < 0.02) for steers fed corn germ than for those fed corn oil. Feeding tallow increased total ruminal VFA (P < 0.03) and NH(3) (P < 0.07) concentrations compared with steers fed the other fat sources. Feeding corn germ led to a greater (P < 0.02) rate of ruminal liquid outflow compared with corn oil. A diet x hour interaction (P < 0.04) occurred for ruminal pH, with steers fed corn oil having the greatest ruminal pH 18 h after feeding, without differences at other time points. Fat supplementation increased (P < 0.09) ruminal concentrations of Fusobacterium necrophorum. Duodenal flow of C18:3n-3 was greater (P < 0.01) for steers fed flax oil compared with those fed corn oil. Feeding corn germ led to less (P < 0.01) ruminal biohydrogenation of fatty acids compared with corn oil. Steers fed tallow had greater small intestinal digestibility of C14:0 (P < 0.02) and C16:1 (P < 0.04) than steers fed the other fat sources. Fat supplementation decreased (P < 0.06) small intestinal digestibility of C18:0. Feeding corn germ decreased (P < 0.10) small intestinal digestibility of C18:1 compared with corn oil. It appears that source of supplemental fat can affect the site and extent of fatty acid and nutrient digestion in steers fed diets based on steam-flaked corn.  相似文献   

Feasibility of using proteins from Salmonella gallinarum vs. 9R live vaccine for the prevention of fowl typhoid in chickens     

K Bouzoubaa  K V Nagaraja  F Z Kabbaj  J A Newman  B S Pomeroy 《Avian diseases》1989,33(3):385-391

Proteins from a field strain of Salmonella gallinarum MSG1 were compared with 9R live vaccine strain for their protection against experimental fowl typhoid in chickens. Proteins from S. gallinarum gave better protection than the 9R live vaccine as measured by clearance of challenge organism from internal organs. Proteins given twice with an adjuvant at 200 micrograms/100 g body weight resulted in 95% protection, compared with 60% protection with 9R given orally. The 9R live vaccine produced more hepatic and splenic lesions and, when administered orally as a single dose, was the least protective (60%). In the group vaccinated subcutaneously with a single dose of 9R without an adjuvant, both the challenge strain and the 9R vaccine strain were isolated from the ovaries of some birds. All chickens vaccinated with 9R strain or with proteins developed antibodies detectable by microagglutination test, and in some vaccinated groups as many as 100% of the birds developed antibody levels detected by seroagglutination.  相似文献   

Quantitation of endotoxin in cell-free rumen fluid of cattle.     

T G Nagaraja  E E Bartley  L R Fina  H D Anthony  S M Dennis  R M Bechtle 《Journal of animal science》1978,46(6):1759-1767

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Effect of breed of cattle on innate resistance to infection with <i>Babesia bovis, B bigemina and Anaplasma marginale     

RE BOCK  AJ de  VOS  TG KINGSTON  DJ McLELLAN 《Australian veterinary journal》1997,75(5):337-340

Objective To assess the innate resistance of naive Bos taurus, Bos taurus cross Bos indicus and Bos indicus cattle to virulent Babesia bovis, B bigemina and Anaplasma marginale parasites. Design Groups of 10, pure B indicus, fi B indicus cross,/B indicus cross and pure B taurus steers were infected with virulent B bovis, B bigemina and A marginale parasites. Procedure Sequential infections were carried out by intravenous inoculation of infected blood containing 1 times 10⁸ parasites of B bovis, followed by B bigemina and then A marginale. To assess resistance, measurements were made of parasitaemia, rectal temperature, packed cell volume and the number within a group requiring chemotherapy to control infection. There was a recovery period between each infection. Results Infection with B bovis showed that pure B indicus steers were significantly more resistant to B bovis infection than the other groups, with none of this group requiring treatment. There was no significant difference between fi B indicus cross and/B indicus cross with 30% and 20%, respectively, of steers in these groups requiring treatment. The pure B taurus steers were significantly more affected then those in the other three groups with 80% requiring treatment. Infections of B bigemina produced a mild response in comparison to that of B bovis and none of the steers required treatment. However, the pure B taurus group was significantly more affected than the other three groups for all other measurements. After the A marginale infection, B indicus steers were moderately affected with 50% requiring treatment, whereas 70% of the fi B indicus group, 80% of the /B indicus cross group and 100% of the pure B taurus group required treatment. Conclusions All breeds of cattle, ranging from pure B indicus to pure B taurus may be at risk of severe disease if exposed to virulent A marginale. The results confirm that pure B indicus cattle are relatively resistant to B bovis, but there could be a significant risk of severe mortalities if cross-bred herds are exposed to virulent infection.  相似文献