Effects of Pasteurella haemolytica A1 leukotoxin on bovine neutrophils: degranulation and generation of oxygen-derived free radicals.     

S K Maheswaran  D J Weiss  M S Kannan  E L Townsend  K R Reddy  L O Whiteley  S Srikumaran 《Veterinary immunology and immunopathology》1992,33(1-2):51-68

To further define the role of Pasteurella haemolytica A1 leukotoxin in the pathogenesis of bovine pneumonic pasteurellosis, its in vitro effects on bovine neutrophils were investigated. Leukotoxin-containing culture supernatant, from P. haemolytica, stimulated a neutrophil respiratory burst as measured by the generation of oxygen-derived free radicals O2- and H2O2. This effect was immediate because preincubation of neutrophils with the culture supernatant for 5 min or longer substantially suppressed this respiratory burst. This suppression was due to cytolysis of the neutrophils. Prolonged incubation of neutrophils with the same culture supernatant caused further cytolysis and degranulation. Heat-inactivated P. haemolytica culture supernatant that had lost its cytotoxic properties failed to stimulate respiratory burst by neutrophils. Furthermore, the respiratory burst, cytolysis and degranulation were abrogated only by leukotoxin-neutralizing monoclonal and polyclonal antibodies, but not by antibodies against the lipopolysaccharide. These studies show that the leukotoxin component in the culture supernatant was responsible for the generation of oxygen-derived free radicals and proteolytic enzymes from neutrophils which may participate in direct lung injury.  相似文献   

Pathogenic mechanisms of caprine arthritis-encephalitis virus   总被引：1，自引：0，他引：1  

E. G. Mdurvwa  P. O. Ogunbiyi  H. S. Gakou  P. G. Reddy 《Veterinary research communications》1994,18(6):483-490

Goats infected with caprine arthritis-encephalitis virus (CAEV) show chronic arthritis and cachexia, which are progressive in nature. The immunopathogenic mechanisms responsible for these progressive clinical symptoms have not been fully elucidated. Various haematological and immunological parameters were evaluated in experimentally-infected goats showing typical signs of CAEV-induced disease. Infected goats showed recurrent lymphocytosis that may be due to constant presentation of antigen by infected cells of a monocyte/macrophage lineage. The serum alkaline phosphatase and -glutamyl transferase concentrations were elevated in infected goats, a characteristic of hepatic and bone disorders. All other serum chemistry parameters were similar between infected and control goats. Importantly, the serum tumour necrosis factor- (TNF-) levels were higher in infected goats. The cachexia seen in infected goats may be at least partly due to altered metabolism as a result of prolonged elevation of serum TNF- levels. Depressed natural killer cell activity was observed in infected goats and may contribute towards the establishment of a persistent infection with CAEV.Abbreviations AIDS acquired immunodeficiency syndrome - CAEV caprine arthritis-encephalitis virus - GGT -glutamyl transferase - HBSS Hanks' balanced salt solution - HIV human immunodeficiency virus - NK natural killer - PBMC peripheral blood mononuclear cells - PCR polymerase chain reaction - SAP serum alkaline phosphatase - TNF tumour necrosis factor  相似文献   

Comparison of maize,wheat and triticale in broiler diets     

N. V. Reddy  D. R. Rao  G. R. Sunki 《British poultry science》1979,20(4):357-362

1. Wheat, triticale 131 or triticale 72‐S could replace up to half the maize in broiler diets without affecting performance. Replacing more of the maize on either an equal nitrogen basis or a weight basis adversely affected performance.

2. Triticale 72‐S appeared to be superior to triticale 131 as a direct replacement for maize, but both grains were inferior to maize as energy sources.  相似文献   

Comparisons of frequencies and egg shell characteristics of broken and intact eggs within diverse populations of chickens     

P. B. Siegel  J. H. Van Middelkoop  P. R. K. Reddy 《British poultry science》1978,19(4):411-416

1. Differences were found among eight populations of White Plymouth Rock pullets in the frequency of broken eggs.

2. The shells of such eggs were thinner than those of intact eggs in seven of the populations.

3. The number of defective eggs, the specific gravity of the eggs, and the percentage hen‐day egg production of normal eggs were significantly correlated within populations with the incidence of broken eggs.

4. No significant correlations were found within populations between the incidence of egg breakage and either egg weight, body weight, or shank length.  相似文献   

Dynamics of Polymyxa graminis and Indian peanut clump virus (IPCV) infection on various monocotyledonous crops and groundnut during the rainy season     

P. Delfosse  A. S. Reddy  K. Thirumala Devi  A. Legrève  J. Risopoulos  D. Doucet  P. Shoba Devi  H. Maraite  D. V. R. Reddy 《Plant pathology》2002,51(5):546-560

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Detection and genetic diversity of porcine rotavirus A,B and C in eastern Australian piggeries     

B Genz  J Gerszon  Y Pollock  B Gleeson  R Shankar  MJ Sellars  RJ Moser 《Australian veterinary journal》2023,101(4):153-163

Rotaviruses (RV) have a high prevalence in piggeries worldwide and are one of the major pathogens causing severe diarrhoea in young pigs. RV species A, B, and C have been linked to piglet diarrhoea in Australian pig herds, but their genetic diversity has not been studied in detail. Based on sequencing of the structural viral protein 7 (VP7) RVA G genotypes G3, G4 and G5, and RVC types G1, G3, G5, and G6 have been identified in Australian piggeries in previous studies. Although occurrence of RVB was reported in Australia in 1988, no further genetic analysis has been conducted. To improve health management decisions in Australian pig herds, more information on RV prevalence and genetic diversity is needed. Here, 243 enteric samples collected from 20 pig farms within Eastern Australia were analysed for the presence of RV in different age groups using a novel PCR-based multiplex assay (Pork MultiPath™ enteric panel). RVA, RVB, and RVC were detected in 10, 14, and 14 farms, respectively. Further sequencing of VP7 in selected RV-positive samples revealed G genotypes G2, G5, G9 (RVA), G6, G8, G14, G16, G20 (RVB), and G1, G3, G5, G6 (RVC) present. RVA was only detected in young (<10 weeks old) pigs whereas RVB and RVC were also detected in older animals (>11 weeks old). Interestingly, RVB and RVC G-type occurrence differed between age groups. In conclusion, this study provides new insights on the prevalence and diversity of different RV species in pig herds of Eastern Australia whilst demonstrating the ability of the Pork MultiPath™ technology to accurately differentiate between these RV species.  相似文献   

不同燕麦品种在尼泊尔北部山区的生长特性及其营养品质的研究     

旦增塔庆  Purna Bhadra Chapagain  Shankar Raj Pant  杰布  格桑顿珠  陈少锋 《草业学报》2021,30(10):73-82

畜牧业是尼泊尔北部山区的重要生计支柱,提升牧草产量是我国对尼泊尔开展农业技术援助的关键领域。为筛选出适宜尼泊尔北部山区栽培的燕麦品种,于2019年5-10月在尼泊尔热索瓦县郎唐山区对12个燕麦品种（爱沃、太阳神、贝勒1、美达、科纳、林纳、青引1号、青海444、青海甜燕麦、陇燕2号、陇燕3号、Kamadhenu）的物候期、株高、产草量、穗含量、叶茎比和关键营养成分等进行了品比试验。结果表明：美达、科纳、青引1号、青海444、青海甜燕麦和Kamadhenu 6个品种能完成生育期,生育天数在115~141 d,其余多数品种只能达到乳熟期。各燕麦品种的株高为134.8~177.7 cm,其中引进品种太阳神、青海444、青海甜燕麦、美达和林纳的株高较对照品种Kamadhenu高6.3%~20.4%,存在极显著差异（P<0.01）。青海甜燕麦、青海444和美达的干草产量分别达到了14723.0、13491.0和13369.6 kg·hm^-2,分别比对照品种Kamadhenu增产36.0%、24.7%和23.6%,差异极显著（P<0.01）。贝勒1、科纳和太阳神的叶茎比分别为0.40、0.38和0.36,是对照品种Kamadhenu的1.50~1.67倍。各燕麦品种的干物质、粗蛋白、总灰分、中性洗涤纤维和酸性洗涤纤维含量变化范围分别为93.5%~95.6%、5.7%~9.9%、4.4%~6.9%、68.2%~78.4%和39.3%~48.7%,其中太阳神的粗蛋白含量是对照品种Kamadhenu的1.57倍,存在极显著差异（P<0.01）。对各燕麦品种的10个农艺性状进行主成分分析及综合评价,结果表明,引进品种青海甜燕麦、美达、青海444和太阳神综合适应性较好,适宜在该地区推广种植。  相似文献   

Prevalence of Salmonella antibodies among goats slaughtered for chevon in Bareilly (Northern India)     

Chandra M  Singh BR  Shankar H  Agarwal M  Agarwal RK  Sharma G  Babu N 《Preventive veterinary medicine》2007,80(1):1-8

We screened serum samples of 1024 goats slaughtered for chevon in Bareilly in Northern India for Salmonella antibodies with indirect ELISA, MAT-H (microagglutination test using flagellar antigens e, n, x and 1, 5) and MAT-O (microagglutination test using somatic antigens 4, 12 and 3, 10, 15). Salmonella antibodies were detected in 48, 8 and 40%, goats using Salmonella-cytotoxi-I ELISA, MAT 'H' and MAT 'O', respectively. After adjusting for test accuracy, the seroprevalence were highest for Salmonella-cytotoxi-I ELISA (46%) followed by agglutinins against 'O' 3, 10, 15 (15%) and negligible for other agglutinins. With all 5 tests, prevalence of Salmonella antibodies was significantly higher in females than in males. No significant difference was evident in prevalence of Salmonella antibodies to different antigens in different age groups of male goats except for e, n, x agglutinins that were significantly more prevalent in young adult (<6-18 months) males than in adult (>18 months of age) or young (< or =6 months of age) goats. On the other hand, in females, prevalence of Salmonella-cytotoxin-I antibodies and e, n, x agglutinins differed significantly among three age groups, being the most prevalent in adult goats. As expected, the results of different tests had little or no correlation because the different tests targeted antibodies to different antigens.  相似文献   

Identification and distribution of fungal pathogens associated with seedling blight of rice in the southern United States     

Shankar P. Gaire  Xin-Gen Zhou  Yong Zhou  Jun Shi  Young-Ki Jo 《Plant pathology》2023,72(1):76-88

Surveys were conducted in the five southern rice-producing states of Arkansas, Louisiana, Mississippi, Missouri and Texas in the United States during the 2018 and 2019 cropping seasons to determine the distribution and pathogenicity of fungal pathogens associated with seedling blight in rice. A total of 349 pathogenic fungal isolates were collected and identified as belonging to four genera: Rhizoctonia solani, Fusarium spp., Sclerotium rolfsii and Marasmius graminum based on morphological characteristics, molecular analysis and Koch's postulates. R. solani (252 out of 349 pathogenic isolates) was the most prevalent fungus isolated from diseased samples. Of the 252 pathogenic R. solani isolates, 245 were further classified as anastomosis group 11 (AG-11) and 7 as AG-4. Isolates of R. solani AG-4 and M. graminum were the most aggressive, with the highest stand loss (63% to 100%) and median disease rating (DR; 5.0), followed by isolates of R. solani AG-11 (stand loss = 4% to 100% and DR = 0.6 to 5.0), Fusarium spp. (stand loss = 26% to 48% and DR = 2.0 to 5.0) and S. rolfsii (stand loss = 33% to 48% and DR = 2.0 to 3.0) in causing seedling blight in rice. R. solani (62% to 83% of total pathogenic isolates) and Fusarium spp. (10% to 24% of total pathogenic isolates) were predominant in all the five states surveyed. S. rolfsii and M. graminum were present only in Louisiana and Texas. The results of this first systematic survey of rice seedling diseases in the southern United States will help develop effective fungicide seed treatment strategies for control of stand loss caused by seedling blight, one of the major factors limiting rice production.  相似文献   

Potential effects of RNA interference of Asian longhorned beetle on its parasitoid     

Xingeng Wang  Jessica Faucher  Ramesh Kumar Dhandapani  Jian J. Duan  Subba Reddy Palli 《Pest management science》2023,79(4):1557-1565

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