Patrick John Wright 1942–2015          下载免费PDF全文

BW Parry  DB Galloway  PD Mansell  JR Watts 《Australian veterinary journal》2016,94(11):399-399

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An on-farm study of the epidemiology of Actinobacillus pleuropneumoniae infection in pigs as part of a vaccine efficacy trial     

Wongnarkpet S  Pfeiffer DU  Morris RS  Fenwick SG 《Preventive veterinary medicine》1999,39(1):1-11

Thirty cohort pigs were followed from birth to slaughter to study epidemiological patterns of porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae. The study was conducted within a larger 380-animal study of vaccination against Mycoplasma hyopneumoniae and A. pleuropneumoniae in a 340-sow farrow-to-finish piggery with 4-month weaning, operating a continuous system of intensive production in the North Island of New Zealand. The cohort pigs were randomly allocated into two equal groups: vaccinated and control. Pigs in the first group were vaccinated at 2 and 4 weeks of age with both M. hyopneumoniae vaccine and A. pleuropneumoniae vaccine at separate vaccination sites. A series of nasal swabs was taken at 4, 8, 10, 11, 12, 14, 16 and 18 weeks of age. Each swab was streaked onto the surface of a selective medium on the farm and the plates were immediately transported to a laboratory and incubated at 37 degrees C for 5 days. After the trial, pigs were slaughtered at an average of 132 days of age, lungs were examined and samples taken for bacteriological culture and isolation. Thirty-five out of 256 samples produced haemolytic colonies which were Gram-negative, V-factor-dependent and positive to the CAMP test. A. pleuropneumoniae was first isolated at 4 weeks of age from one vaccinated pig. This finding suggests that piglets became infected in the farrowing pen and the source of infection might be a carrier sow. The interval-specific cumulative incidence of A. pleuropneumoniae infection reached a maximum of 54% and 40% at 11 weeks of age in the vaccinated and control groups, respectively. Infection status of the litter is considered to be a factor influencing morbidity in infected herds during weaner and grower periods. Our results suggest that simultaneous vaccination with M. hyopneumoniae and A. pleuropneumoniae vaccines at 2 and 4 weeks of age might lessen the prevalence but cannot absolutely prevent A. pleuropneumoniae infection during the weaner or grower-finisher periods.  相似文献   

Evaluation of canine Bordetella bronchiseptica isolates using randomly amplified polymorphic DNA fingerprinting and ribotyping   总被引：2，自引：0，他引：2  

Keil DJ  Fenwick B 《Veterinary microbiology》1999,66(1):41-51

Bordetella bronchiseptica is a respiratory tract pathogen in a variety of species. Previous studies suggest little genetic variation among canine B. bronchiseptica isolates. The degree of genetic diversity in 26 canine B. bronchiseptica strains was evaluated using randomly amplified polymorphic DNA (RAPD) fingerprinting and ribotyping. Strains evaluated include historic reference strains (N=3). vaccine strains (N=5) and clinical isolates (N=18). RAPD fingerprinting with the 10-nucleotide primer OPA-4 resulted in four distinct fingerprint patterns. RAPD fingerprinting consistently separated four previously characterized electromorphotype (EMT) 6 strains into two fingerprint types. Ribotyping, using the restriction endonuclease PvuI, resulted in six distinct ribotypes. With the exception of vaccine strains, considerable genetic diversity exists in the canine B. bronchiseptica isolates examined. These findings indicate the genetic variability within canine strains of B. bronchiseptica is greater than appreciated previously. Additionally, OPA-4 RAPD fingerprinting and PvuI ribotyping will be useful tools in epidemiologic studies of canine B. bronchiseptica isolates.  相似文献   

Use of a tetanus toxoid marker to allow differentiation of infected from vaccinated poultry without affecting the efficacy of a H5N1 avian influenza virus vaccine     

James-Berry CM  Middleton D  Mansfield JP  Fenwick SG  Ellis TM 《The Veterinary record》2010,167(18):695-699

Tetanus toxoid (TT) was assessed as a positive marker for avian influenza (AI) virus vaccination in chickens, in a vaccination and challenge study. Chickens were vaccinated twice with inactivated AI H5N2 virus vaccine, and then challenged three weeks later with highly pathogenic AI H5N1 virus. Vaccinated chickens were compared with other groups that were either sham-vaccinated or vaccinated with virus with the TT marker. All sham-vaccinated chickens died by 36 hours postinfection, whereas all vaccinated chickens, with or without the TT marker, were protected from morbidity and mortality following exposure to the challenge virus. Serological testing for H5-specific antibodies identified anamnestic responses to H5 in some of the vaccinated birds, indicating active virus infection.  相似文献   

Contributions of disease resistance and escape to the control of septoria tritici blotch of wheat     

L. S. Arraiano †  N. Balaam ‡  P. M. Fenwick  C. Chapman  D. Feuerhelm †  P. Howell §  S. J. Smith ¶  J. P. Widdowson  J. K. M. Brown 《Plant pathology》2009,58(5):910-922

The contributions of disease escape and disease resistance to the responses of wheat to septoria tritici leaf blotch (STB) were analysed in a set of 226 lines, including modern cultivars, breeding lines and their progenitors dating back to the origin of scientific wheat breeding. Field trials were located in the important wheat-growing region of eastern England and were subject to natural infection by Mycosphaerella graminicola . STB scores were related to disease-escape traits, notably height, leaf spacing, leaf morphology and heading date, and to the presence of known Stb resistance genes and isolate-specific resistances. The Stb6 resistance gene was associated with a reduction of 19% in the level of STB in the complete set of 226 lines and with a 33% reduction in a subset of 139 lines of semidwarf stature. Greater plant height was strongly associated with reduced STB in the full set of lines, but only weakly in the semidwarf lines. Shorter leaf length was also associated with reduced STB, but, in contrast to earlier reports, lines with more prostrate leaves had more STB on average, probably because they tended to have longer leaves. Several lines, notably cvs Pastiche and Exsept, had low mean levels of STB which could not be explained by either escape traits or specific resistance genes, implying that they have unknown genes for partial resistance to STB.  相似文献   

Post partum subclinical hypocalcaemia and effects on ovarian function and uterine involution in a dairy herd.     

R Kamgarpour  R C Daniel  D C Fenwick  K Mcguigan  G Murphy 《Veterinary journal (London, England : 1997)》1999,158(1):59-67

Episodes of subclinical hypocalcaemia occurred in the first 6 weeks after calving in 6 out of 12 multiparous Friesian cows calving in the winter period and 7 out of 23 calving in the summer in a subtropical environment. In the winter calving group, there were significant (P< 0.05) decreases in mean plasma calcium concentrations (PTCa) on days 6, 27 and 36 after calving in those animals unable to maintain PTCa >2.0 mmol/L in the first 21 days. These cows had a significantly higher mean body weight and higher mean milk production than normocalcaemic cows. In the summer calving group, the seven cows with episodes of subclinical hypocalcaemia had significantly lower mean PTCa over periods of 21 and 60 days. Intervals until involution of the uterus were negatively (P< 0.05) correlated with mean PTCa over the first 21 and 30 days after calving in the winter and summer calving groups (r = -0.62 and -0.42), respectively. The mean size of the first ovulated follicles was significantly smaller in cows showing episodes of subclinical hypocalcaemia in the winter group and the mean number of ovulatory size follicles was less in these cows at 15 days (P< 0.001) (1.2 +/- 0.17 vs 2.3 +/- 0.21) and at 30 days (P< 0.03) (3.5 +/- 0.43 vs 5.2 +/- 0.54). During the first three dioestrus periods, mean plasma progesterone concentration as a function of corpus luteum area was significantly lower (P< 0.05) in the cows with episodes of subclinical hypocalcaemia in the winter group.  相似文献   

Strain- and growth condition-dependent variability in outer membrane protein expression by Bordetella bronchiseptica isolates from dogs.     

D J Keil  B Fenwick 《American journal of veterinary research》1999,60(8):1016-1021

OBJECTIVE: To characterize strain-dependent and growth condition-dependent variability in outer membrane protein (OMP) expression of Bordetella bronchiseptica isolates from dogs and evaluate the systemic immune response to OMP of B bronchiseptica among infected dogs. SAMPLE POPULATION: 8 strains of B bronchiseptica isolated from dogs, including a historic reference strain, 2 commercially available vaccine strains, and 5 field strains, and serum samples collected from 3 specific-pathogen-free (SPF) dogs before and 1 month after infection with B bronchiseptica. PROCEDURE: OMP were isolated from cultures in the late exponential phase of growth and compared among strains and, within strains, among growth conditions by means of polyacrylamide gel electrophoresis and immunoblotting. Serum samples were probed with OMP from 1 of the field strains. RESULTS: Strain-dependent variability in OMP profiles and growth condition-dependent and strain-dependent variability in expression of filamentous hemagglutinin (FHA) and pertactin was found, along with heterogeneity of the pertactin proteins produced by these B bronchiseptica strains. All 3 SPF dogs seroconverted to proteins with estimated molecular masses of 200 and 66 kDa, suggesting that FHA and pertactin were involved in the immunologic response of these dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that there is growth condition and strain variability in expression of OMP, FHA, and pertactin proteins produced by B bronchiseptica. This information could be useful in the improvement of vaccines for prevention of bordetellosis in dogs.  相似文献   

Pasteurellaceae isolated from tonsillar samples of commercially-reared American bison (Bison bison).   总被引：2，自引：2，他引：0       下载免费PDF全文

A C Ward  N W Dyer    B W Fenwick 《Canadian journal of veterinary research》1999,63(3):161-165

As commercial producers of American bison (Bison bison) become more numerous, concerns relative to bison health management increase. Since loss due to respiratory disease associated with Pasteurella and related Pasteurellaceae is a major concern for cattle producers, a study was conducted to determine what types of Pasteurellaceae are carried by bison to evaluate the potential of pneumonic pasteurellosis in bison herds where management practices are comparable to those used for cattle. Tonsillar biopsies, collected in May (n = 29) and August (n = 25) 1997 from 24- to 30-month-old bison bulls, at the time of slaughter were cultured for Pasteurellaceae. Pasteurella spp. were isolated from all the samples collected in May. These included isolates identified as P. haemolytica, trehalosi, testudinis, and multocida subsp. multocida a and multocida b. Actinobacillus spp. and Haemophilus somnus were also isolated from some samples. Pasteurella spp., haemolytica, trehalosi, and multocida subsp. multocida a, multocida b and septica, plus 2 nonspeciated indole-positive biotypes, U2 and U16, were isolated from the second group of tonsil samples. Most of these organisms, including P. haemolytica, P. multocida subsp., and H. somnus are associated with disease in domestic livestock and should be regarded as potential pathogens for bison, particularly in animals which become stressed by management practices commonly used with cattle such as herding, crowding, and shipping.  相似文献   

The effects of hypocalcaemia due to a 4-hour infusion of Na2EDTA solution on various blood and urine analytes in dairy cows and a comparison of these effects between cows with high and low erythrocyte potassium concentrations.     

D C Fenwick  R C Daniel 《The British veterinary journal》1992,148(4):283-299

Six HK (high erythrocyte potassium) and 7 LK (low erythrocyte potassium) dairy cows were subjected to a 4-h intravenous infusion of 4.7% Na2EDTA solution to induce and maintain hypocalcaemia. Blood samples taken immediately before infusion, hourly for 7 h, and at 24 h after commencement of infusion were subjected to determination of concentration (or count) of 16 analytes. The mean changes in concentrations (or counts) of the various blood analytes were calculated for the periods 0-4, 4-7, 7-24, and 0-24 h after commencement of the infusion for all cows combined, and then separately for the HK and LK groups of cows. Plasma Ca(PCa), plasma inorganic phosphorus (PiP) and plasma potassium (PK) showed significant decreases during the 4-h infusion period and were still below pretreatment levels 24 h later. AST, CPK, PCVs and white cell-counts (WCCs) showed significant early increases which were still significantly elevated 24 h later. Plasma magnesium (PMg) and erythrocyte Na(ENa) and K(EK) all showed delayed changes which still persisted 24 h later. Significant between-group differences were present for PCVs which increased significantly more in the LK than the HK group during the infusion period, for PCa which showed a greater increase in the HK cows than the LK cows during the 4-7 h early clinical recovery period, and for plasma bilirubin (PBil) which showed a greater increase from 0 to 24 h in the HK group than in the LK group. Urine samples, collected before infusion, 4-7 h and 24 h after commencement of the infusion, were subjected to analysis for glucose, protein, pH, 'blood' and ketones. Most cows showed increases in urinary glucose, protein and 'blood'.  相似文献   

Sodium dependent ion transporters in trout gills     

G. Flik  T. Kaneko  A.M. Greco  J. Li  J.C. Fenwick 《Fish physiology and biochemistry》1997,17(1-6):385-396

Biochemical procedures developed to isolate plasma membranes from the branchial epithelium of rainbow trout (Oncorhynchus mykiss) yield membrane fractions that are specifically enriched in the plasma membrane marker enzyme Na⁺/K⁺-ATPase. As the bulk of the branchial Na⁺/K⁺-ATPase is assumed to be confined to the mitochondria-rich chloride cells, such membrane preparations must contain the essence of the enzymatic machinery of the chloride cells. Basal Na⁺ activity in branchial (chloride) cells is around 10 millimolar and, accordingly, we find a K_m for Na⁺ of the Na⁺/K⁺-ATPase of 13 millimolar, indicating that the enzyme may be regulated by changes in cytosolic sodium. The Na⁺-gradient across the serosal plasma membrane created by this pump provides energy for 3Na⁺/Ca²⁺-exchange and bumetanide-sensitive Na⁺/K⁺/2Cl^--cotransport. Here we further postulate the presence of a Na⁺/Cl^--cotransporter, indicated by thiazide-sensitive, bumetanide-insensitive transport of Na⁺ and Cl^-; this cotransporter activity awaits the characterization of its kinetics. The Na⁺/Ca²⁺-exchanger has kinetic characteristics compatible with a regulatory role of cytosolic Na⁺ in the activity of this carrier. Both Na⁺/Ca²⁺-exchange and Ca²⁺-ATPase activity may contribute to transport of Ca²⁺, the former having lower affinity for calcium but a higher capacity than the latter carrier. The Na⁺/K⁺/2Cl^--cotransporter has kinetics that favor a regulatory role for plasma K⁺ in the activity of this carrier. Seawater adaptation leads to increased activity of cotransporter molecules in the plasma membrane fractions (the activity increases relative to that of the Na⁺/K⁺-ATPase) and this may reflect a function in Cl^--extrusion performed by the chloride cells in a seawater environment. A function for the cotransporter in the gills of freshwater fish may be the regulation of cell volume.  相似文献