خيارات البحث
النتائج 1 - 10 من 86
Relationship between Mycoplasma hyosynoviae infection and front limb weakness in Duroc swine.
1987
Lawrisuk L.S. | Rothschild M.F. | Ross R.F. | Christian L.L.
Genotypic and phenotypic variation of biotypes coexisting in the Hickman strain of Newcastle disease virus.
1986
McMillan B.C. | Hanson R.P.
Restriction endonuclease analysis of a porcine isolate of bovine herpesvirus type I.
1994
Varady E. | Tuboly T. | Derbyshire J.B.
Molecular study of Cysticercus tenuicollis from slaughtered sheep in Sulaymaniyah province, Iraq النص الكامل
2020
Mohammed, Aram Ahmad
Molecular study of Cysticercus tenuicollis from slaughtered sheep in Sulaymaniyah province, Iraq النص الكامل
2020
Mohammed, Aram Ahmad
Cysticercosis caused by the larval stage of Taenia hydatigena is economically the most important endemic parasitic disease in Iraq. Few data are available relating to the genetic divergence of this helminth. This study aimed to molecularly characterise Cysticercus tenuicollis isolates from sheep in Sulaymaniyah province, Iraq. DNA extraction and amplification of specimens of C. tenuicollis from 46 sheep were conducted by PCR for the mitochondrial 12S rRNA gene. The 19 amplicons were subjected to purification and partial sequencing. Five 12S rRNA nucleotide sequence haplotypes were found. The pairwise nucleotide difference between haplotypes of 12S rRNA gene ranged from 0.2% to 0.7%. Four out of the five haplotypes of C. tenuicollis contained one to two base mutations and were discovered in Iraq for the first time, and this may be a unique mutation globally which has not been recorded previously. Three newly recorded haplotypes contained only one single mutation, and the other one contained two mutations. Phylogenetic analysis showed that all isolated strains were closely related to Iranian sheep isolates. Four new strains of T. hydatigena were discovered for the first time in the study area.
اظهر المزيد [+] اقل [-]Molecular study of Cysticercus tenuicollis from slaughtered sheep in Sulaymaniyah province, Iraq النص الكامل
2020
Mohammed Aram Ahmad
Cysticercosis caused by the larval stage of Taenia hydatigena is economically the most important endemic parasitic disease in Iraq. Few data are available relating to the genetic divergence of this helminth. This study aimed to molecularly characterise Cysticercus tenuicollis isolates from sheep in Sulaymaniyah province, Iraq.
اظهر المزيد [+] اقل [-]Molecular characterisation and genetic diversity of canine parvovirus type 2 prevalent in Central China النص الكامل
2020
Hu, Wen | Xu, Xin | Liu, Qiang | Ji, Jun | Kan, Yunchao | Yao, Lunguang | Bi, Yingzuo | Xie, Qingmei
Molecular characterisation and genetic diversity of canine parvovirus type 2 prevalent in Central China النص الكامل
2020
Hu, Wen | Xu, Xin | Liu, Qiang | Ji, Jun | Kan, Yunchao | Yao, Lunguang | Bi, Yingzuo | Xie, Qingmei
Canine parvovirus (CPV) disease is one of the most threatening to domestic and wild dogs. A total of 132 clinical samples were isolated from domestic dogs with diarrhoea from Henan, Hubei, Jiangsu, and Anhui provinces from 2016 to 2017, and 56 were positive for CPV-2 by PCR. A phylogenetic tree was constructed for the isolate sequences incorporating 53 non-Chinese reference strains. VP2 sequences showed the strains mainly to be new CPV-2a/2b and CPV-2c genotypes. The Ala5Gly, Phe267Tyr, Ser297Ala, Tyr324Ile, Gln370Arg, Asn426Asp or Asn426Glu, and Thr440Ala sites in the VP2 protein antigenic region were found to have high mutation rates. The VP2 tertiary structural model shows that the change at these mutation points is a factor for the changes in the protein structure. Significant differences between the Central Chinese strains and others were found, indicating that evolution is geographically related and extended in major regions. The homology between the identified strains confirmed their relationship. Phylogenetic analysis indicated that the common genotypes in the same clusters differ slightly in homology and evolutionary history. This epidemiological study enriches the available data and serves as an important reference for studies on the evolution of CPV and selection of vaccines in China.
اظهر المزيد [+] اقل [-]Molecular characterisation and genetic diversity of canine parvovirus type 2 prevalent in Central China النص الكامل
2020
Hu Wen | Xu Xin | Liu Qiang | Ji Jun | Kan Yunchao | Yao Lunguang | Bi Yingzuo | Xie Qingmei
Canine parvovirus (CPV) disease is one of the most threatening to domestic and wild dogs.
اظهر المزيد [+] اقل [-]Genetic diversity of Campylobacter jejuni isolated from the poultry food chain النص الكامل
2019
Wieczorek Kinga | Osek Jacek
Genetic diversity of Campylobacter jejuni isolated from the poultry food chain النص الكامل
2019
Wieczorek Kinga | Osek Jacek
Introduction:Campylobacter jejuni is one of the most frequently reported causes of foodborne bacterial enteric disease worldwide. The main source of these microorganisms is contaminated food, especially of poultry origin. There are several molecular methods for differentiation of Campylobacter isolates at the subgenus level, and one of these is porA-typing based on the sequencing of the major outer-membrane protein (MOMP) encoding gene. The aim of the study was to test the molecular relationship of C. jejuni strains isolated at different points along the poultry food chain and assess the population structure of the isolates.
اظهر المزيد [+] اقل [-]Genetic diversity of Campylobacter jejuni isolated from the poultry food chain النص الكامل
2019
Wieczorek, Kinga | Osek, Jacek
Introduction: Campylobacter jejuni is one of the most frequently reported causes of foodborne bacterial enteric disease worldwide. The main source of these microorganisms is contaminated food, especially of poultry origin. There are several molecular methods for differentiation of Campylobacter isolates at the subgenus level, and one of these is porA-typing based on the sequencing of the major outer-membrane protein (MOMP) encoding gene. The aim of the study was to test the molecular relationship of C. jejuni strains isolated at different points along the poultry food chain and assess the population structure of the isolates. Material and Methods: A total of 451 C. jejuni were used in the study, and a DNA fragment of 630 bp of the MOMP encoding gene was amplified and sequenced. Results: One hundred and ten sequence types were identified, with 69 (62.7%) unique to the isolates' origin and 30 not present in the database. The most prevalent nucleotide variant 1 was detected in 37 (8.2%) strains. These isolates were identified in all poultry sources tested, especially in faeces (15 isolates) but also in poultry carcasses and meat (11 isolates in each). Conclusion: The porA typing method was highly discriminative for C. jejuni of poultry origin since the Simpson's diversity index (D) achieved a value of 0.876, indicating considerable diversity in the bacterial population tested. The method may be further used for epidemiological investigation purposes.
اظهر المزيد [+] اقل [-]Molecular detection and genetic diversity of porcine circovirus type 3 in commercial pig farms in Xinjiang province, China النص الكامل
2019
Mengfan, Qiao | Xifeng, Wang | Guowu, Zhang | Qingling, Meng | Jun, Qiao | Lixia, Wang | Kuojun, Cai | Jinsheng, Zhang | Zaichao, Zhang | Weiwei, Yu | Yelong, Peng | Xuepeng, Cai
Molecular detection and genetic diversity of porcine circovirus type 3 in commercial pig farms in Xinjiang province, China النص الكامل
2019
Mengfan, Qiao | Xifeng, Wang | Guowu, Zhang | Qingling, Meng | Jun, Qiao | Lixia, Wang | Kuojun, Cai | Jinsheng, Zhang | Zaichao, Zhang | Weiwei, Yu | Yelong, Peng | Xuepeng, Cai
Porcine circovirus type 3 (PCV3) is a newly discovered porcine circovirus. The molecular characteristics and genetic evolution of PCV3 in Xinjiang province, China still being unclear, the aim of the study was their elucidation. A total of 393 clinical samples were collected from pigs on commercial farms in nine different regions of Xinjiang and phylogenetic analysis based on full-length Cap genes was performed. The prevalence at farm level was 100%, while in all the tested samples it was 22.39%. Nine PCV3 strains were detected in Xinjiang province and they shared 98.9–99.3% nucleotide and 97.5–100.0% Cap gene amino acid sequence identities with other epidemic strains from China and abroad. Compared with other epidemic strains of PCV3, there were 26 base mutation sites in the Cap gene in the nine Xinjiang strains, resulting in the mutation of amino acids at positions 20, 24, 75, 77, 108, 111 and 206. Phylogenetic analysis showed that these strains can be divided into two different genetic groups, to the first of which five strains affiliated and divided between subgroups 1.1 and 1.2, and to the second of which the other four strains affiliated and similarly divided between subgroups 2.1 and 2.2. PCV3 circulates widely among commercial pig farms in Xinjiang province, China, and displays obvious genetic diversity. The results provide epidemiological information useful for the prevention and control of PCV3 infection in the pig industry.
اظهر المزيد [+] اقل [-]Molecular detection and genetic diversity of porcine circovirus type 3 in commercial pig farms in Xinjiang province, China النص الكامل
2019
Mengfan Qiao | Xifeng Wang | Guowu Zhang | Qingling Meng | Jun Qiao | Lixia Wang | Kuojun Cai | Jinsheng Zhang | Zaichao Zhang | Weiwei Yu | Yelong Peng | Xuepeng Cai
Porcine circovirus type 3 (PCV3) is a newly discovered porcine circovirus. The molecular characteristics and genetic evolution of PCV3 in Xinjiang province, China still being unclear, the aim of the study was their elucidation.
اظهر المزيد [+] اقل [-]Phylogenetic study of H5 low pathogenic avian influenza viruses detected in wild birds in Poland in 2010−2015 النص الكامل
2017
Świętoń, Edyta | Śmietanka, Krzysztof
Phylogenetic study of H5 low pathogenic avian influenza viruses detected in wild birds in Poland in 2010−2015 النص الكامل
2017
Świętoń, Edyta | Śmietanka, Krzysztof
Introduction: The genomes of nine H5 subtypes of low pathogenic avian influenza virus (LPAIV) strains identified in wild birds in Poland between 2010 and 2015 were sequenced, and their phylogenetic relationship was determined. Material and Methods: AIV genome segments were amplified by RT-PCR and the PCR products were sequenced using Sanger method. Phylogenetic trees were generated in MEGA6 software and digital genotyping approach was used to visualise the relationship between analysed strains and other AIVs. Results: High genetic diversity was found in the analysed strains as multiple subgroups were identified in phylogenetic trees. In the HA tree, Polish strains clustered in two distinct subclades. High diversity was found for PB2, PB1, PA and NP, since 5-8 sublineages could be distinguished. Each strain had a different gene constellation, although relationship of as much as six out of eight gene segments was observed between two isolates. A relationship with poultry isolates was found for at least one segment of each Polish strain. Conclusion: The genome configuration of tested strains indicates extensive reassortment, although the preference for specific gene constellation could be noticed. A significant relationship with isolates of poultry origin underlines the need for constant monitoring of the AIV gene pool circulating in the natural reservoir.
اظهر المزيد [+] اقل [-]Phylogenetic study of H5 low pathogenic avian influenza viruses detected in wild birds in Poland in 2010−2015 النص الكامل
2017
Świętoń Edyta | Śmietanka Krzysztof
Introduction: The genomes of nine H5 subtypes of low pathogenic avian influenza virus (LPAIV) strains identified in wild birds in Poland between 2010 and 2015 were sequenced, and their phylogenetic relationship was determined.
اظهر المزيد [+] اقل [-]Meta-analysis of genetic diversity of the VP1 gene among the circulating O, A, and SAT2 serotypes and vaccine strains of FMD virus in Egypt النص الكامل
2020
El Nahas, Abeer F. | Salem, Sayed A.H.
Meta-analysis of genetic diversity of the VP1 gene among the circulating O, A, and SAT2 serotypes and vaccine strains of FMD virus in Egypt النص الكامل
2020
El Nahas, Abeer F. | Salem, Sayed A.H.
Three strains of the FMD virus (A, O, and SAT 2) were recognised as causes of the FMD circulating in Egypt. The aims of this study were to trace the FMDV isolates from outbreaks in Egypt to understand their epidemiology and evolution and to understand the situation of the vaccine strains compared with the circulating serotypes. A meta-analysis was carried out by using the data available for FMD outbreaks in Egypt from GenBank and the World Reference Laboratory for Foot-and-Mouth Disease (WRLFMD); a comparison was done with both data sets for the three serotypes. MEGA-X was used for the evolution analysis, through constructions of phylogenetic trees for all sequences recorded in GenBank for each serotype in different Egyptian outbreaks in different years and also within the same year. Additionally, nucleotide substitution rate, molecular clock, and mean evolutionary rates were estimated for the three serotypes to understand and compare their evolution. Absence of some records of certain serotype outbreaks from the WRLFMD database was noted as were subsequent missing appropriate vaccine programmes. Genetic variation was recorded among the virus isolates within the same years and also the vaccine strain was associated with up to 26 amino acid substitutions. The evolution rate of the SAT2 strain was the highest of the circulating strains. SAT2 had high amino acid substitution per year at an important immunogenic site (130–170), serotype A had less, and serotype O the least. The need for different strategies for vaccine serotype selection is indicated.
اظهر المزيد [+] اقل [-]Meta-analysis of genetic diversity of the VP1 gene among the circulating O, A, and SAT2 serotypes and vaccine strains of FMD virus in Egypt النص الكامل
2020
El Nahas Abeer F. | Salem Sayed A.H.
Three strains of the FMD virus (A, O, and SAT 2) were recognised as causes of the FMD circulating in Egypt. The aims of this study were to trace the FMDV isolates from outbreaks in Egypt to understand their epidemiology and evolution and to understand the situation of the vaccine strains compared with the circulating serotypes.
اظهر المزيد [+] اقل [-]