Peste des Petits ruminants (PPR) is considered as one of the major constraints to the productivity of small ruminants in Sudan. Presently, control measures for PPR are primarily reliant on vaccination using an attenua...Peste des Petits ruminants (PPR) is considered as one of the major constraints to the productivity of small ruminants in Sudan. Presently, control measures for PPR are primarily reliant on vaccination using an attenuated PPR strain Nigeria 75/1 that has been produced in monolayers of Vero cells grown in static flasks. This study investigates the potential for scaling up PPR vaccine production using roller bottle technology, a more advanced method. A live, homologous vaccine against PPR in sheep and goats was successfully produced on a large scale in roller culture bottles, with DMEM supplemented with ten percent fetal bovine serum serving as the growth medium. The cells were infected with a multiplicity of infection of 0.01, and the vaccine was harvested when the cytopathic effect reached 80%. The vaccine was then freeze-dried to preserve its stability. A series of tests were conducted to ensure the safety and quality of the vaccine. Using PCR, the identity of vaccine was confirmed. It was found to be safe in both single and 100-times dose inoculations in sheep, with the produced batches showing a high titre of 6.4 ± 0.11 log10 TCID50/ml. All batches met the criteria of sterility, passing tests for bacteria, fungi, and mycoplasma. Furthermore, the vaccine proved effective in small ruminants, with antibodies persisting for over a year post-vaccination. The residual moisture content remained below 2.5%, and the vaccine successfully passed vacuum testing. Stability tests indicated that the vaccine has a shelf-life of at least one year when stored at temperatures of 2˚C - 8˚C and −20˚C. These results demonstrate the potential for applying roller bottle culture technology to PPR vaccine production, significantly streamlining the existing process and enhancing its efficiency. Further research is warranted to address the economic analyses of adopting roller bottle technology with existing PPR control program.展开更多
Peste des petits ruminants virus (PPRV) antibodies were studied in Sudanese sheep and goats (n = 855) before and after vaccination with a locally produced Nigeria 75/1 vaccine using a commercial competitive ELISA (cEL...Peste des petits ruminants virus (PPRV) antibodies were studied in Sudanese sheep and goats (n = 855) before and after vaccination with a locally produced Nigeria 75/1 vaccine using a commercial competitive ELISA (cELISA) kit. Animals were kept healthy under field conditions, in four states: Blue Nile (n = 250), North Kordofan (n = 189), South Darfur (n = 225) and the Northern State (n = 191). Before vaccination, the overall sero-prevalence of PPRV antibodies was 54.6% (53.2% - 56%, 95% CI);high (64.8% - 76.4%, 95% CI) in Blue Nile State, medium (50.5% - 61.9%, 95% CI) in North Kordofan State and South Darfur State and low (28.6% - 35.2% 95%, CI) in Northern State. In high-risk areas (high sero-prevalence), Blue Nile (70.4%) and North Kordofan (57.7%), middle age groups (7 - 12 and 13 - 18 months) were identified as high-risk age. Middle age groups showed lower sero-prevalence than preceding (3 - 6 months) and subsequent (>18 months) age groups while the risk of exposure increased with age. Current and previous findings suggested a transmission pathway of PPRV involving the South Eastern border (Blue Nile) and neighbouring Central Sudan to North Kordofan. One month after vaccination 88.4% (343/388) of sero-negative animals were sero-converted suggesting the efficacy of the locally produced Nigeria 75/1 vaccine. Even if only individuals in the high-risk age group (7 - 18 months) were vaccinated, the overall population immunity (OPI) in high-risk areas (the Blue Nile and North Kordofan) would have surpassed the threshold of 70%, which is indicated for blocking PPRV transmission. However, lower vaccination coverage is expected in wider vaccination programmes. These findings primarily justified the targeting of PPR control in Sudan through the vaccination of high-risk age groups in high-risk areas.展开更多
In 2013,peste des petits ruminants(PPR)re-emerged in China and spread to the majority of provinces across the country.The disease was effectively controlled through a vaccination campaign employing live attenuated vac...In 2013,peste des petits ruminants(PPR)re-emerged in China and spread to the majority of provinces across the country.The disease was effectively controlled through a vaccination campaign employing live attenuated vaccines,although sporadic cases still occurred.However,limited information is currently available regarding the peste des petits ruminants virus(PPRV)endemic in China.Here,a PPRV strain(HLJ/13)was isolated from a field sample in China using Vero cells expressing goat signalling lymphocyte activation molecule.Phylogenetic analysis indicated that HLJ/13 belonged to lineage IV.Subsequent intranasal and subcutaneous inoculation of goats with a dose of 2×10~6 TCID50of HLJ/13 resulted in the development of typical clinical symptoms of PPR,including pyrexia,ocular and nasal discharges,stomatitis,and diarrhea.All infected goats succumbed to the disease by day 8.To gain further insight,viral loading,pathological examination and immunohistochemical analyses were conducted,elucidating the main targets of HLJ/13 as the respiratory system,digestive tract and lymphoid organs.Employing the goat infection model established above,the goat poxvirus-vectored PPR vaccine,which was previously developed and could be used as DIVA(differentiating infected from vaccinated animals)vaccine,provided complete protection against the challenge of HLJ/13.It is important to note that this study represents the first comprehensive report delineating the biology and pathogenicity characterization,and infection model of PPRV isolated in China.展开更多
Peste des petits ruminants(PPR) is a highly contagious transboundary animal disease with a severe socio-economic impact on the livestock industry, particularly in poor countries where it is endemic. Full understanding...Peste des petits ruminants(PPR) is a highly contagious transboundary animal disease with a severe socio-economic impact on the livestock industry, particularly in poor countries where it is endemic. Full understanding of PPR virus(PPRV)pathobiology and molecular biology is critical for effective control and eradication of the disease. To achieve these goals,establishment of stable reverse genetics systems for PPRV would play a key role. Unfortunately, this powerful technology remains less accessible and poorly documented for PPRV. In this review, we discussed the current status of PPRV reverse genetics as well as the recent innovations and advances in the reverse genetics of other non-segmented negative-sense RNA viruses that could be applicable to PPRV. These strategies may contribute to the improvement of existing techniques and/or the development of new reverse genetics systems for PPRV.展开更多
Peste ties petits ruminants is a kind of acute eontagious disease infecting goats anti sheep. In this study, antibtly monitoring and tracking of healthy goat and sheep immunized by peste des petits ruminants vaccine i...Peste ties petits ruminants is a kind of acute eontagious disease infecting goats anti sheep. In this study, antibtly monitoring and tracking of healthy goat and sheep immunized by peste des petits ruminants vaccine in Changping District of Beijing City were conducted, aiming at providing a reference for the devel- opment of effective immunization procedures.展开更多
Peste des petits ruminant (PPR) is a contagious disease of small ruminants caused by a virus that belongs to the genus Morbillivirus of the family Paramyxoviridae. This study aimed to determine the seroprevalence of P...Peste des petits ruminant (PPR) is a contagious disease of small ruminants caused by a virus that belongs to the genus Morbillivirus of the family Paramyxoviridae. This study aimed to determine the seroprevalence of PPR disease in sheep and goats and its associated risk factors in Kassala State, Eastern Sudan. Across sectional study was conducted during the period from 30th August to 25th November 2015. The study was carried out using a structured questionnaire survey and a total of 918 blood samples were collected from apparently healthy unvaccinated sheep and goats in different localities in State of Kassala. A total of 546 sheep and 372 goats were tested for specific antibodies to nucleoprotein (NP) by competitive enzyme linked immunosorbent assay (cELISA). The apparent overall prevalence of PPR antibodies in Kassala was 58.2% while the true prevalence was calculated to be 61.3%. The apparent prevalence in sheep and goats was 68.1% and 43.5% respectively. Univariate analysis showed that the risk factors had significant associations with a cELISA positive status: locality, species, age, breed, husbandry system, housing mode, animals movement (p = 0.000) and animals sharing pasture and water (p = 0.003), while sex and newly introduced animals were not significant risk factors (p = 0.771) (p = 0.050) respectively. Factors found that significantly associated (p < 0.05) with increased odds of being cELISA positive in multivariate analysis were localities, species, age and newly introduced animals. The prevalence differed between localities and was the highest in the River Atbara (84.0%) locality, whereas it was lowest in Delta North (29.0%). No significant difference was observed among the sexes. However, the prevalence differed in different age groups and was 52.25% in animals of less than six months old;49.3% were between seven months and two years old and 65.5% were above two years old. In different husbandry systems, the prevalence was 47.9%, 73.0% and 49.2% in intensive, open grazing and pastoral systems respectively. Housing type effects were also observed;the highest prevalence was in animals housed in metal fence (83.3%). The movement pattern showed significant effect, where the prevalence was the highest (81.3%) in animals that move inter-states/inter-localities. It is concluded that the disease is endemic in Kassala State, high prevalent in sheep and goats, posing a threat to animal exportation, and may have a serious economic influence. Owners and herders should compulsorily vaccinate their animals yearly and animals should be investigated periodically for implementation of crucial eradication program.展开更多
[ Objective] The paper was to get effective soluble N protein to establish indirect ELISA method for Peste des petits ruminants （PPR）. [ Method] Soluble N protein with high expression was obtained from Escherichia c...[ Objective] The paper was to get effective soluble N protein to establish indirect ELISA method for Peste des petits ruminants （PPR）. [ Method] Soluble N protein with high expression was obtained from Escherichia coli expression system through codon optimization and optimization of expression conditions, and indirect ELISA detection method based on N protein was further established. [ Result] The assay had no cross reaction with other sheep pathogens. The intra- and inter-batch variation coefficients were less than 9%, indicating the method had good repeatability. Furthermore, totally 480 clinical serum samples were detec- ted by the assay, and the agreement rate with commercial ELISA kit （IDVET） was 98.33%. [ Conclusion] The study laid a foundation for further development of mature PPRV antibody detection kits.展开更多
The present study was carried out between April 2015 and January 2016 to estimate the sero-prevalence and identify the risk factors of the peste des petits ruminants (PPR) in Cameroon. A total of 269 herds randomly sa...The present study was carried out between April 2015 and January 2016 to estimate the sero-prevalence and identify the risk factors of the peste des petits ruminants (PPR) in Cameroon. A total of 269 herds randomly sampled across the country have been studied and 1622 samples of serum have been levied on the sheep and goat. The c-ELISA has been studied in order to detect the presence of antibodies in small ruminants like an indicator of exposition to PPRV. The results revealed the circulation of PPRV in the country with a total sero-prevalence of 39% [95%CI;37 - 41] and a sero-prevalence of 63.2% [95%CI;57.2 - 69.2] at the herd level. Sero-prevalence was variable in the ten regions ranging from 7% [95% CI;6.2 - 8.4] to 73% [95% CI;62 - 84] with the northern zone (Adamawa, North and Far-North) having 52.3% [95% CI;37 - 60] and southern zone (including the remaining seven regions) recording 29% [95% CI;11 - 57]. Similarly, it was higher in animals found in urban/peri-urban areas than in rural areas with prevalence ratio of 2.9 [95% CI 2.54 - 3.4;p < 0.001] <em>i.e. </em>3 times more, 1.6 [95% CI 1.36 - 1.90;p < 0.001] <em>i.e.</em> 1.6 times more, and 5.02 [95% CI 3.91 - 6.85;p < 0.001] <em>i.e.</em> 5 times more at national level, in the northern zone and in the southern area, respectively. Five risk factors have been identified: the breeding environment, introduction of new animals into the herds, gathering of animals for pasture and watering, wandering and transhumance. The breeding area appeared to be the most important risk factor associated with disease exposure. The control measures for the eradication of this disease must take into account the epidemiological situation, the breeding environment, animal transhumance and breeding system.展开更多
[Objectives]This study was conducted to establish a rapid quantitative method for detecting antibody against Peste des Petits Ruminants Virus(PPR V)in sheep serum.[Methods]Soluble N protein and NH fusion protein were ...[Objectives]This study was conducted to establish a rapid quantitative method for detecting antibody against Peste des Petits Ruminants Virus(PPR V)in sheep serum.[Methods]Soluble N protein and NH fusion protein were obtained in Escherichia coli prokaryotic expression system by optimizing codons and expression conditions of E.coli.Furthermore,based on the purified soluble N protein and NH fusion protein,a high-sensitivity fluorescence immunoassay kit for detecting the antibody against PPR V was established.[Results]The method could quickly and quantitatively detect PPR V antibody in sheep serum,with high sensitivity and specificity,without any cross reaction to other related sheep pathogens.The intra-batch and inter-batch coefficients of variation were less than 10%and 15%,respectively,and the method had good repeatability.Through detection on 292 clinical serum samples,it was compared with the French IDVET competitive ELISA kit,and the coincidence rate of the two methods reached 93.84%.Compared with the serum neutralization test,the detected titer value of the high-sensitivity rapid fluorescence quantitative detection method was basically consistent with the tilter value obtained by the neutralization test on the standard positive serum(provided by the WOAH Brucellosis Reference Laboratory of France).[Conclusions]This method can realize rapid quantitative detection of PPR V antibody on site,and has high practical value and popularization value.展开更多
[Objectives]This study was conducted to explore rapid and large-scale screening and detection of peste des petits ruminants(PPR),so as to provide important technical means for prevention,control and purification of PP...[Objectives]This study was conducted to explore rapid and large-scale screening and detection of peste des petits ruminants(PPR),so as to provide important technical means for prevention,control and purification of PPR.[Methods]Soluble N protein and NH fusion protein were successfully obtained in an Escherichia coli expression system by optimizing E.coli codon and expression conditions.Furthermore,based on purified soluble N protein and NH fusion protein,a double-antigen sandwich time-resolved fluorescence immunoassay method for detection of peste des petits ruminants virus(PPRV)was established.[Results]The method has high sensitivity and specificity and can specifically detect the antibody against PPRV in sheep serum,and it has no cross reaction with other related diseases.The method was used to detect 292 clinical samples,and compared with French IDVET competition ELISA kit.The coincidence rates of positive samples and negative samples from the two kinds of test kits were 92.47%and 97.26%,respectively,and the overall coincidence rate was 94.86%.The intra-group and inter-group coefficients of variation in the repeatability test were less than 10%.[Conclusions]Compared with the traditional ELISA method,the double-antigen sandwich time-resolved fluorescence immunoassay for detection of PPRV has equivalent sensitivity and specificity,and simple and rapid operation,and thus high application and popularization value.展开更多
[Objectives]This study was conducted to enhance the prevention and control of peste des petits ruminants(PPR)and goatpox(GTP).[Methods]Two experimental sheep farms in Northern Shandong were selected to conduct a compa...[Objectives]This study was conducted to enhance the prevention and control of peste des petits ruminants(PPR)and goatpox(GTP).[Methods]Two experimental sheep farms in Northern Shandong were selected to conduct a comparative experiment between separate vaccinations for PPR and GTP and immunization with a combined live vaccine for both diseases.Antibody levels were measured to assess immunization effect on days 7,14,21 and 28 after vaccination.[Results]The qualified rates of group immune antibodies in both the experimental and control groups exceeded 75%,achieving the goal of preventing both PPR and GTP through a single immunization.[Conclusions]This study provides clinical application references for the prevention of PPR and GTP in the local area.展开更多
Dashilan et Liulichang,situés au centre-ville de Beijing,sont des quartiers historiques et culturels renommés.Un musée discret se niche dans le dédale de petites maisons aux murs gris:le Mus&...Dashilan et Liulichang,situés au centre-ville de Beijing,sont des quartiers historiques et culturels renommés.Un musée discret se niche dans le dédale de petites maisons aux murs gris:le Musée de la cour n°93.Depuis 2014,il favorise la diffusion du patrimoine culturel immatériel et des arts populaires.展开更多
The search for mechanical properties of materials reached a highly acclaimed level, when indentations could be analysed on the basis of elastic theory for hardness and elastic modulus. The mathematical formulas proved...The search for mechanical properties of materials reached a highly acclaimed level, when indentations could be analysed on the basis of elastic theory for hardness and elastic modulus. The mathematical formulas proved to be very complicated, and various trials were published between the 1900s and 2000s. The development of indentation instruments and the wish to make the application in numerous steps easier, led in 1992 to trials with iterations by using relative values instead of absolute ones. Excessive iterations of computers with 3 + 8 free parameters of the loading and unloading curves became possible and were implemented into the instruments and worldwide standards. The physical formula for hardness was defined as force over area. For the conical, pyramidal, and spherical indenters, one simply took the projected area for the calculation of the indentation depth from the projected area, adjusted it later by the iterations with respect to fused quartz or aluminium as standard materials, and called it “contact height”. Continuously measured indentation loading curves were formulated as loading force over depth square. The unloading curves after release of the indenter used the initial steepness of the pressure relief for the calculation of what was (and is) incorrectly called “Young’s modulus”. But it is not unidirectional. And for the spherical indentations’ loading curve, they defined the indentation force over depth raised to 3/2 (but without R/h correction). They till now (2025) violate the energy law, because they use all applied force for the indenter depth and ignore the obvious sidewise force upon indentation (cf. e.g. the wood cleaving). The various refinements led to more and more complicated formulas that could not be reasonably calculated with them. One decided to use 3 + 8 free-parameter iterations for fitting to the (poor) standards of fused quartz or aluminium. The mechanical values of these were considered to be “true”. This is till now the worldwide standard of DIN-ISO-ASTM-14577, avoiding overcomplicated formulas with their complexity. Some of these are shown in the Introduction Section. By doing so, one avoided the understanding of indentation results on a physical basis. However, we open a simple way to obtain absolute values (though still on the blackbox instrument’s unsuitable force calibration). We do not iterate but calculate algebraically on the basis of the correct, physically deduced exponent of the loading force parabolas with h3/2 instead of false “h2” (for the spherical indentation, there is a calotte-radius over depth correction), and we reveal the physical errors taken up in the official worldwide “14577-Standard”. Importantly, we reveal the hitherto fully overlooked phase transitions under load that are not detectable with the false exponent. Phase-transition twinning is even present and falsifies the iteration standards. Instead of elasticity theory, we use the well-defined geometry of these indentations. By doing so, we reach simple algebraically calculable formulas and find the physical indentation hardness of materials with their onset depth, onset force and energy, as well as their phase-transition energy (temperature dependent also its activation energy). The most important phase transitions are our absolute algebraically calculated results. The now most easily obtained phase transitions under load are very dangerous because they produce polymorph interfaces between the changed and the unchanged material. It was found and published by high-enlargement microscopy (5000-fold) that these trouble spots are the sites for the development of stable, 1 to 2 µm long, micro-cracks (stable for months). If however, a force higher than the one of their formation occurs to them, these grow to catastrophic crash. That works equally with turbulences at the pickle fork of airliners. After the publication of these facts and after three fatal crashing had occurred in a short sequence, FAA (Federal Aviation Agency) reacted by rechecking all airplanes for such micro cracks. These were now found in a new fleet of airliners from where the three crashed ones came. These were previously overlooked. FAA became aware of that risk and grounded 290 (certainly all) of them, because the material of these did not have higher phase-transition onset and energy than other airplanes with better material. They did so despite the 14577-Standard that does not find (and thus formally forbids) phase transitions under indenter load with the false exponent on the indentation parabola. However, this “Standard” will, despite the present author’s well-founded petition, not be corrected for the next 5 years.展开更多
文摘Peste des Petits ruminants (PPR) is considered as one of the major constraints to the productivity of small ruminants in Sudan. Presently, control measures for PPR are primarily reliant on vaccination using an attenuated PPR strain Nigeria 75/1 that has been produced in monolayers of Vero cells grown in static flasks. This study investigates the potential for scaling up PPR vaccine production using roller bottle technology, a more advanced method. A live, homologous vaccine against PPR in sheep and goats was successfully produced on a large scale in roller culture bottles, with DMEM supplemented with ten percent fetal bovine serum serving as the growth medium. The cells were infected with a multiplicity of infection of 0.01, and the vaccine was harvested when the cytopathic effect reached 80%. The vaccine was then freeze-dried to preserve its stability. A series of tests were conducted to ensure the safety and quality of the vaccine. Using PCR, the identity of vaccine was confirmed. It was found to be safe in both single and 100-times dose inoculations in sheep, with the produced batches showing a high titre of 6.4 ± 0.11 log10 TCID50/ml. All batches met the criteria of sterility, passing tests for bacteria, fungi, and mycoplasma. Furthermore, the vaccine proved effective in small ruminants, with antibodies persisting for over a year post-vaccination. The residual moisture content remained below 2.5%, and the vaccine successfully passed vacuum testing. Stability tests indicated that the vaccine has a shelf-life of at least one year when stored at temperatures of 2˚C - 8˚C and −20˚C. These results demonstrate the potential for applying roller bottle culture technology to PPR vaccine production, significantly streamlining the existing process and enhancing its efficiency. Further research is warranted to address the economic analyses of adopting roller bottle technology with existing PPR control program.
文摘Peste des petits ruminants virus (PPRV) antibodies were studied in Sudanese sheep and goats (n = 855) before and after vaccination with a locally produced Nigeria 75/1 vaccine using a commercial competitive ELISA (cELISA) kit. Animals were kept healthy under field conditions, in four states: Blue Nile (n = 250), North Kordofan (n = 189), South Darfur (n = 225) and the Northern State (n = 191). Before vaccination, the overall sero-prevalence of PPRV antibodies was 54.6% (53.2% - 56%, 95% CI);high (64.8% - 76.4%, 95% CI) in Blue Nile State, medium (50.5% - 61.9%, 95% CI) in North Kordofan State and South Darfur State and low (28.6% - 35.2% 95%, CI) in Northern State. In high-risk areas (high sero-prevalence), Blue Nile (70.4%) and North Kordofan (57.7%), middle age groups (7 - 12 and 13 - 18 months) were identified as high-risk age. Middle age groups showed lower sero-prevalence than preceding (3 - 6 months) and subsequent (>18 months) age groups while the risk of exposure increased with age. Current and previous findings suggested a transmission pathway of PPRV involving the South Eastern border (Blue Nile) and neighbouring Central Sudan to North Kordofan. One month after vaccination 88.4% (343/388) of sero-negative animals were sero-converted suggesting the efficacy of the locally produced Nigeria 75/1 vaccine. Even if only individuals in the high-risk age group (7 - 18 months) were vaccinated, the overall population immunity (OPI) in high-risk areas (the Blue Nile and North Kordofan) would have surpassed the threshold of 70%, which is indicated for blocking PPRV transmission. However, lower vaccination coverage is expected in wider vaccination programmes. These findings primarily justified the targeting of PPR control in Sudan through the vaccination of high-risk age groups in high-risk areas.
基金supported by the National Key Research and Development Program of China(2016YFD0500108)the International S&T Cooperation Program of China(ISTCP)(2015DFA31300)。
文摘In 2013,peste des petits ruminants(PPR)re-emerged in China and spread to the majority of provinces across the country.The disease was effectively controlled through a vaccination campaign employing live attenuated vaccines,although sporadic cases still occurred.However,limited information is currently available regarding the peste des petits ruminants virus(PPRV)endemic in China.Here,a PPRV strain(HLJ/13)was isolated from a field sample in China using Vero cells expressing goat signalling lymphocyte activation molecule.Phylogenetic analysis indicated that HLJ/13 belonged to lineage IV.Subsequent intranasal and subcutaneous inoculation of goats with a dose of 2×10~6 TCID50of HLJ/13 resulted in the development of typical clinical symptoms of PPR,including pyrexia,ocular and nasal discharges,stomatitis,and diarrhea.All infected goats succumbed to the disease by day 8.To gain further insight,viral loading,pathological examination and immunohistochemical analyses were conducted,elucidating the main targets of HLJ/13 as the respiratory system,digestive tract and lymphoid organs.Employing the goat infection model established above,the goat poxvirus-vectored PPR vaccine,which was previously developed and could be used as DIVA(differentiating infected from vaccinated animals)vaccine,provided complete protection against the challenge of HLJ/13.It is important to note that this study represents the first comprehensive report delineating the biology and pathogenicity characterization,and infection model of PPRV isolated in China.
基金supported by the National Key Research and Development Program of China (2016YFD0500108 and 2016YFE0204100)the International Cooperation Project of CAAS Innovation Program (CAAS-GJHZ201700X)
文摘Peste des petits ruminants(PPR) is a highly contagious transboundary animal disease with a severe socio-economic impact on the livestock industry, particularly in poor countries where it is endemic. Full understanding of PPR virus(PPRV)pathobiology and molecular biology is critical for effective control and eradication of the disease. To achieve these goals,establishment of stable reverse genetics systems for PPRV would play a key role. Unfortunately, this powerful technology remains less accessible and poorly documented for PPRV. In this review, we discussed the current status of PPRV reverse genetics as well as the recent innovations and advances in the reverse genetics of other non-segmented negative-sense RNA viruses that could be applicable to PPRV. These strategies may contribute to the improvement of existing techniques and/or the development of new reverse genetics systems for PPRV.
文摘Peste ties petits ruminants is a kind of acute eontagious disease infecting goats anti sheep. In this study, antibtly monitoring and tracking of healthy goat and sheep immunized by peste des petits ruminants vaccine in Changping District of Beijing City were conducted, aiming at providing a reference for the devel- opment of effective immunization procedures.
文摘Peste des petits ruminant (PPR) is a contagious disease of small ruminants caused by a virus that belongs to the genus Morbillivirus of the family Paramyxoviridae. This study aimed to determine the seroprevalence of PPR disease in sheep and goats and its associated risk factors in Kassala State, Eastern Sudan. Across sectional study was conducted during the period from 30th August to 25th November 2015. The study was carried out using a structured questionnaire survey and a total of 918 blood samples were collected from apparently healthy unvaccinated sheep and goats in different localities in State of Kassala. A total of 546 sheep and 372 goats were tested for specific antibodies to nucleoprotein (NP) by competitive enzyme linked immunosorbent assay (cELISA). The apparent overall prevalence of PPR antibodies in Kassala was 58.2% while the true prevalence was calculated to be 61.3%. The apparent prevalence in sheep and goats was 68.1% and 43.5% respectively. Univariate analysis showed that the risk factors had significant associations with a cELISA positive status: locality, species, age, breed, husbandry system, housing mode, animals movement (p = 0.000) and animals sharing pasture and water (p = 0.003), while sex and newly introduced animals were not significant risk factors (p = 0.771) (p = 0.050) respectively. Factors found that significantly associated (p < 0.05) with increased odds of being cELISA positive in multivariate analysis were localities, species, age and newly introduced animals. The prevalence differed between localities and was the highest in the River Atbara (84.0%) locality, whereas it was lowest in Delta North (29.0%). No significant difference was observed among the sexes. However, the prevalence differed in different age groups and was 52.25% in animals of less than six months old;49.3% were between seven months and two years old and 65.5% were above two years old. In different husbandry systems, the prevalence was 47.9%, 73.0% and 49.2% in intensive, open grazing and pastoral systems respectively. Housing type effects were also observed;the highest prevalence was in animals housed in metal fence (83.3%). The movement pattern showed significant effect, where the prevalence was the highest (81.3%) in animals that move inter-states/inter-localities. It is concluded that the disease is endemic in Kassala State, high prevalent in sheep and goats, posing a threat to animal exportation, and may have a serious economic influence. Owners and herders should compulsorily vaccinate their animals yearly and animals should be investigated periodically for implementation of crucial eradication program.
基金Supported by New Diagnosis and Detection Technology Research for Major Animal Diseases in Cattle and Sheep(No.2016YFD0500901)
文摘[ Objective] The paper was to get effective soluble N protein to establish indirect ELISA method for Peste des petits ruminants （PPR）. [ Method] Soluble N protein with high expression was obtained from Escherichia coli expression system through codon optimization and optimization of expression conditions, and indirect ELISA detection method based on N protein was further established. [ Result] The assay had no cross reaction with other sheep pathogens. The intra- and inter-batch variation coefficients were less than 9%, indicating the method had good repeatability. Furthermore, totally 480 clinical serum samples were detec- ted by the assay, and the agreement rate with commercial ELISA kit （IDVET） was 98.33%. [ Conclusion] The study laid a foundation for further development of mature PPRV antibody detection kits.
文摘The present study was carried out between April 2015 and January 2016 to estimate the sero-prevalence and identify the risk factors of the peste des petits ruminants (PPR) in Cameroon. A total of 269 herds randomly sampled across the country have been studied and 1622 samples of serum have been levied on the sheep and goat. The c-ELISA has been studied in order to detect the presence of antibodies in small ruminants like an indicator of exposition to PPRV. The results revealed the circulation of PPRV in the country with a total sero-prevalence of 39% [95%CI;37 - 41] and a sero-prevalence of 63.2% [95%CI;57.2 - 69.2] at the herd level. Sero-prevalence was variable in the ten regions ranging from 7% [95% CI;6.2 - 8.4] to 73% [95% CI;62 - 84] with the northern zone (Adamawa, North and Far-North) having 52.3% [95% CI;37 - 60] and southern zone (including the remaining seven regions) recording 29% [95% CI;11 - 57]. Similarly, it was higher in animals found in urban/peri-urban areas than in rural areas with prevalence ratio of 2.9 [95% CI 2.54 - 3.4;p < 0.001] <em>i.e. </em>3 times more, 1.6 [95% CI 1.36 - 1.90;p < 0.001] <em>i.e.</em> 1.6 times more, and 5.02 [95% CI 3.91 - 6.85;p < 0.001] <em>i.e.</em> 5 times more at national level, in the northern zone and in the southern area, respectively. Five risk factors have been identified: the breeding environment, introduction of new animals into the herds, gathering of animals for pasture and watering, wandering and transhumance. The breeding area appeared to be the most important risk factor associated with disease exposure. The control measures for the eradication of this disease must take into account the epidemiological situation, the breeding environment, animal transhumance and breeding system.
基金Supported by The National Project for the Prevention and Control of Major Exotic Animal Diseases(2022YFD1800500)National Mutton Sheep Industrial Technology System(CARS39).
文摘[Objectives]This study was conducted to establish a rapid quantitative method for detecting antibody against Peste des Petits Ruminants Virus(PPR V)in sheep serum.[Methods]Soluble N protein and NH fusion protein were obtained in Escherichia coli prokaryotic expression system by optimizing codons and expression conditions of E.coli.Furthermore,based on the purified soluble N protein and NH fusion protein,a high-sensitivity fluorescence immunoassay kit for detecting the antibody against PPR V was established.[Results]The method could quickly and quantitatively detect PPR V antibody in sheep serum,with high sensitivity and specificity,without any cross reaction to other related sheep pathogens.The intra-batch and inter-batch coefficients of variation were less than 10%and 15%,respectively,and the method had good repeatability.Through detection on 292 clinical serum samples,it was compared with the French IDVET competitive ELISA kit,and the coincidence rate of the two methods reached 93.84%.Compared with the serum neutralization test,the detected titer value of the high-sensitivity rapid fluorescence quantitative detection method was basically consistent with the tilter value obtained by the neutralization test on the standard positive serum(provided by the WOAH Brucellosis Reference Laboratory of France).[Conclusions]This method can realize rapid quantitative detection of PPR V antibody on site,and has high practical value and popularization value.
基金Supported by National Key R&D Program for the Prevention and Control of Major Exotic Animal Diseases(2022YFD1800500)National Mutton Sheep Industrial Technology System(CARS39)+2 种基金Key Research and Development Program of Shandong Province(Major Science and Technology Innovation Project)(2021CXGC011306)Scientific Research Project of General Administration of Customs(2024HK033)Scientific Research Project of Jinan Customs(2023JK005).
文摘[Objectives]This study was conducted to explore rapid and large-scale screening and detection of peste des petits ruminants(PPR),so as to provide important technical means for prevention,control and purification of PPR.[Methods]Soluble N protein and NH fusion protein were successfully obtained in an Escherichia coli expression system by optimizing E.coli codon and expression conditions.Furthermore,based on purified soluble N protein and NH fusion protein,a double-antigen sandwich time-resolved fluorescence immunoassay method for detection of peste des petits ruminants virus(PPRV)was established.[Results]The method has high sensitivity and specificity and can specifically detect the antibody against PPRV in sheep serum,and it has no cross reaction with other related diseases.The method was used to detect 292 clinical samples,and compared with French IDVET competition ELISA kit.The coincidence rates of positive samples and negative samples from the two kinds of test kits were 92.47%and 97.26%,respectively,and the overall coincidence rate was 94.86%.The intra-group and inter-group coefficients of variation in the repeatability test were less than 10%.[Conclusions]Compared with the traditional ELISA method,the double-antigen sandwich time-resolved fluorescence immunoassay for detection of PPRV has equivalent sensitivity and specificity,and simple and rapid operation,and thus high application and popularization value.
基金Supported by Shandong Provincial Sheep Industry Technology System Position Expert Project(SDAIT-10-06)Binzhou Municipal Science and Technology Innovation Policy Guidance Plan Project for the Agricultural Social Service Field(2023SHFZ004).
文摘[Objectives]This study was conducted to enhance the prevention and control of peste des petits ruminants(PPR)and goatpox(GTP).[Methods]Two experimental sheep farms in Northern Shandong were selected to conduct a comparative experiment between separate vaccinations for PPR and GTP and immunization with a combined live vaccine for both diseases.Antibody levels were measured to assess immunization effect on days 7,14,21 and 28 after vaccination.[Results]The qualified rates of group immune antibodies in both the experimental and control groups exceeded 75%,achieving the goal of preventing both PPR and GTP through a single immunization.[Conclusions]This study provides clinical application references for the prevention of PPR and GTP in the local area.
文摘Dashilan et Liulichang,situés au centre-ville de Beijing,sont des quartiers historiques et culturels renommés.Un musée discret se niche dans le dédale de petites maisons aux murs gris:le Musée de la cour n°93.Depuis 2014,il favorise la diffusion du patrimoine culturel immatériel et des arts populaires.
文摘The search for mechanical properties of materials reached a highly acclaimed level, when indentations could be analysed on the basis of elastic theory for hardness and elastic modulus. The mathematical formulas proved to be very complicated, and various trials were published between the 1900s and 2000s. The development of indentation instruments and the wish to make the application in numerous steps easier, led in 1992 to trials with iterations by using relative values instead of absolute ones. Excessive iterations of computers with 3 + 8 free parameters of the loading and unloading curves became possible and were implemented into the instruments and worldwide standards. The physical formula for hardness was defined as force over area. For the conical, pyramidal, and spherical indenters, one simply took the projected area for the calculation of the indentation depth from the projected area, adjusted it later by the iterations with respect to fused quartz or aluminium as standard materials, and called it “contact height”. Continuously measured indentation loading curves were formulated as loading force over depth square. The unloading curves after release of the indenter used the initial steepness of the pressure relief for the calculation of what was (and is) incorrectly called “Young’s modulus”. But it is not unidirectional. And for the spherical indentations’ loading curve, they defined the indentation force over depth raised to 3/2 (but without R/h correction). They till now (2025) violate the energy law, because they use all applied force for the indenter depth and ignore the obvious sidewise force upon indentation (cf. e.g. the wood cleaving). The various refinements led to more and more complicated formulas that could not be reasonably calculated with them. One decided to use 3 + 8 free-parameter iterations for fitting to the (poor) standards of fused quartz or aluminium. The mechanical values of these were considered to be “true”. This is till now the worldwide standard of DIN-ISO-ASTM-14577, avoiding overcomplicated formulas with their complexity. Some of these are shown in the Introduction Section. By doing so, one avoided the understanding of indentation results on a physical basis. However, we open a simple way to obtain absolute values (though still on the blackbox instrument’s unsuitable force calibration). We do not iterate but calculate algebraically on the basis of the correct, physically deduced exponent of the loading force parabolas with h3/2 instead of false “h2” (for the spherical indentation, there is a calotte-radius over depth correction), and we reveal the physical errors taken up in the official worldwide “14577-Standard”. Importantly, we reveal the hitherto fully overlooked phase transitions under load that are not detectable with the false exponent. Phase-transition twinning is even present and falsifies the iteration standards. Instead of elasticity theory, we use the well-defined geometry of these indentations. By doing so, we reach simple algebraically calculable formulas and find the physical indentation hardness of materials with their onset depth, onset force and energy, as well as their phase-transition energy (temperature dependent also its activation energy). The most important phase transitions are our absolute algebraically calculated results. The now most easily obtained phase transitions under load are very dangerous because they produce polymorph interfaces between the changed and the unchanged material. It was found and published by high-enlargement microscopy (5000-fold) that these trouble spots are the sites for the development of stable, 1 to 2 µm long, micro-cracks (stable for months). If however, a force higher than the one of their formation occurs to them, these grow to catastrophic crash. That works equally with turbulences at the pickle fork of airliners. After the publication of these facts and after three fatal crashing had occurred in a short sequence, FAA (Federal Aviation Agency) reacted by rechecking all airplanes for such micro cracks. These were now found in a new fleet of airliners from where the three crashed ones came. These were previously overlooked. FAA became aware of that risk and grounded 290 (certainly all) of them, because the material of these did not have higher phase-transition onset and energy than other airplanes with better material. They did so despite the 14577-Standard that does not find (and thus formally forbids) phase transitions under indenter load with the false exponent on the indentation parabola. However, this “Standard” will, despite the present author’s well-founded petition, not be corrected for the next 5 years.
