Papers by Imadeldin Aradaib
Journal of Virological Methods, 2009
A nested reverse transcriptase (RT) polymerase chain reaction (RT-PCR), for rapid detection of Af... more A nested reverse transcriptase (RT) polymerase chain reaction (RT-PCR), for rapid detection of African horse sickness virus (AHSV) double-stranded ribonucleic acid (dsRNA) in cell culture and tissue samples, was developed and evaluated. Using an outer pair of primers (P1 and P2), selected from genome segment three of AHSV serotype 6 (AHSV-6), the RT-PCR-based assay resulted in amplification of a 890 base pair (bp) primary PCR product. RNAs from the nine vaccine strains of AHSV, and a number of AHSV field isolates including the Central African isolates of AHSV-9 and AHSV-6, propagated in cell cultures, were detected by this assay. A second pair of nested primers (P3 and P4) was used to produce a 240-bp PCR product. The RT-PCR described below detected as little as 0.1 fg of AHSV RNA, which is equivalent to six viral particles. The nested amplification confirmed the integrity of the primary PCR product and increased the sensitivity of the PCR assay by at least 1000-fold. Application of this RT-PCR assay to clinical samples resulted in direct detection of AHSV dsRNA from blood and a variety of tissue samples collected from equines infected experimentally and naturally.
Veterinary Research Communications, 2006
A simple and rapid method for detection of African horse sickness virus serogroup in cell culture... more A simple and rapid method for detection of African horse sickness virus serogroup in cell cultures using RT-PCR. Veterinary Research Communications, 30(3), 319^324
Research Journal of Medical Sciences, 2010
The potential of the Reverse Transcriptase (RT) Polymerase Chain Reaction (RT-PCR)-based assay fo... more The potential of the Reverse Transcriptase (RT) Polymerase Chain Reaction (RT-PCR)-based assay for detection of Rift Valley Fever Virus (RVFV) ribonucleic acid (RNA) in cell culture and clinical samples was evaluated. Sets of oligoribonucleotide primers, selected from the small (S) RNA genome segment of RVFV virus, were used as targets for PCR amplification. The outer pair of primers (RVFV1 and RVFV2) resulted in amplification of a primary 310 base pair (bp) PCR product. Using a pair of internal (semi-nested) primers (RVFV3 and RVFV2), the RT-PCR assay produced a 240 bp PCR product. The primary and the semi-nested PCR products were amplified from RNAs extracted from RVFV field isolates and vaccine strains, propagated in Vero cell cultures. Application of this RT-PCR-based assay to clinical samples resulted in direct detection of RVFV RNAs in spleen, liver, blood and serum samples from naturally infected calves and humans. Amplification products were not detected when the RT-PCR-based assay was applied to RNA from other related hemorrhagic fevers viruses including, Crimean Congo Hemorrhagic Fever (CCHF); dengue virus; Epizootic Hemorrhagic Disease Virus (EHDV); total nucleic acid extracts from uninfected Vero cells. and blood and tissue samples from uninfected humans and animals. The described RT-PCR based assay provides a rapid, sensitive and specific assay for direct detection of RVFV in cell culture and tissue samples and should be recommended for inclusion during an outbreak of the disease among humans and susceptible livestock.
Pakistan Journal of Biological Sciences, 2007
ARADAIB, I., R. OMER, A. MAJID: Kinetics of antibody response of calves immunized with Schistosom... more ARADAIB, I., R. OMER, A. MAJID: Kinetics of antibody response of calves immunized with Schistosoma mansoni glutathione-S-transferase. Vet. arhiv 73, 17-25, 2003.
Ciencia Rural, 1995
Cinco bezerros foram infectados experimentalmente com 30.000 cercarias de Schistosoma bovis e trê... more Cinco bezerros foram infectados experimentalmente com 30.000 cercarias de Schistosoma bovis e três bezerros foram usados como controle. Ovos de S. bovis apareceram inicialmente nas fezes dos animais infectados pela 5a semana após infecção e todos os animais estavam eliminando ovos na 6a semana após infecção. Entre as 7a e 9a semanas após infecção, nas quais a quantidade fecal de ovos era mais alta, os animais infectados manifestaram diarréia com muco seguida por disenteria e os animais apresentando-se morimbundos e depressivos. PCV e concentração da hemoglobina dos animais infectados demonstrou redução progressiva em comparação com os bezerros não infectados. Os animais foram necropsiados na 12a semana para determinação da densidade de ovos nos tecidos e quantidade de parasitas.
Comparative Immunology Microbiology and Infectious Diseases, 1997
The potential use of the recently reported polymerase chain reaction (PCR) protocol for detection... more The potential use of the recently reported polymerase chain reaction (PCR) protocol for detection of United States epizootic hemorrhagic disease virus (EHDV) serotype 1 (EHDV-I) and serotype 2 (EHDV-2) ribonucleic acid in cell culture and clinical specimens was evaluated for detection of Sudanese EHDV strains. EHDV serotype 5 (EHDV-5) and EHDV, isolate 318 (untyped) designated (EHDV-318), recovered from sentinel calves at the Khartoum University farm (Sudan) were studied. RNA from EHDV-5 and EHDV-318 and a number of EHDV field isolates, propagated in cell cultures, were detected by the described PCR-based assay. The specific 387 bp PCR products were visualized on ethidium bromide stained agarose gel. Specificity of the PCR products was confirmed by chemiluminescent hybridization with non-radiolabeled internal probe. Amplification product was not detected when the PCR-based assay was applied to RNA from bluetongue virus (BTV) prototypes serotypes 2, 10, 11, 13, 16 and 17; total nucleic acid extracts from uninfected BHK-21 cells. The results of this study indicated that the previously described EHDV PCR assay could be applied for detection of Sudanese as well as United States strains of EHDV serogroup. In addition, the described EHDV-PCR assay could be used as a supportive diagnostic assay to the current conventional virus isolation procedures used for detection of EHDV infection in susceptible ruminants. ((_2 1997 Elsevier Science Ltd
Veterinary Research Communications, 2005
Archives of Virology, 1995
The diagnostic potential of the polymerase chain reaction (PCR) for specific identification of ep... more The diagnostic potential of the polymerase chain reaction (PCR) for specific identification of epizootic hemorrhagic disease virus serotype 1 (EHDV-1) in cell culture and clinical specimens was evaluated. Using oligonucleotide primers, selected from genome segment 2 of EHDV-1 (New Jersey strain), the PCR-based assay resulted in a 862 base pair (bp) PCR product. EHDV-1 RNA from United States prototype serotype 1 and a number of EHDV-1 field isolates, propagated in cell cultures, were detected by this PCR based assay. The specific 862 bp PCR products were visualized on ethidium bromide-stained agarose gel. Identity of the PCR product was confirmed by chemiluminescent hybridization with non radiolabelled internal probe. Using chemiluminescent hybridization, the sensitivity of the PCR assay was 1.0 fg of virus RNA (equivalent to 60 virus particles). Amplification product was not detected when the PCR-based assay was applied to RNA from EHDV serotype 2 (EHDV-2); the United States bluetongue virus (BLU) prototypes serotypes 2, 10, 11, 13, and 17; total nucleic acid extracts from uninfected BHK-21 cell; or blood cells from calves and deer that were EHDV-seronegative and virus isolation negative. Application of this EHDV-1 PCR-based assay to clinical samples resulted in detection of EHDV-1 RNA from blood samples, collected from a calf experimentally infected with EHDV-1. The described PCR-based assay provides a simple, rapid, sensitive, specific and inexpensive method for specific identification of EHDV-1 infection in susceptible ruminants.
PCR amplification technology for the detection of epizootic hemorrhagic disease virus (EHDV) ribo... more PCR amplification technology for the detection of epizootic hemorrhagic disease virus (EHDV) ribonucleic acid in cell culture and clinical specimens was developed. With oligoribonucleotide primers selected from genome segment 10 of EHDV serotype 1 (EHDV-1), which codes for two nonstructural proteins (NS3 and NS3a), the PCR-based assay resulted in a 535-bp PCR product. RNAs from North American EHDV-1 prototype, EHDV-2 prototype, and a number of EHDV field isolates, including the Central African isolates of EHDV-5 and EHDV-318 propagated in cell cultures, were detected by this PCR-based assay. The specific 535-bp PCR products were visualized onto agarose gels, and the identity of the PCR products was confirmed by chemiluminescent hybridization with a 352-bp internal probe. The sensitivity of the EHDV PCR assay was increased by chemiluminescent hybridization; by this EHDV-NS3 PCR, 10 fg of EHDV RNA was detected (equivalent to 600 viral particles). Amplification product was not detected when the PCR-based assay was applied to RNAs from North American bluetongue virus prototype serotypes 2, 10, 11, 13, and 17; total nucleic acid extracts from uninfected BHK-21 cells; or unfractionated blood from calves and deer that were EHDV seronegative and virus isolation negative. The described EHDV PCR-based assay with primers derived from segment 10 of EHDV-1 resulted in detection of EHDV RNA from blood and tissues collected from calves and deer with natural and experimental EHDV infections and provides a valuable tool to study the epidemiology of EHDV infection in
Veterinary Parasitology, 2010
in central, western and southern Sudan. Hydatid cysts were present in 59% (466/779) of camels, 6%... more in central, western and southern Sudan. Hydatid cysts were present in 59% (466/779) of camels, 6% (299/4893) of cattle, 11% (1180/10,422) of sheep and 2% (106/5565) of goats, with little variation among different geographical areas. 532 of these cysts were examined by PCR and could be overwhelmingly (98.7%) allocated to Echinococcus canadensis G6/7 (all of 215 cysts from camels, 112 of 114 cysts from cattle, 134 of 138 cysts from sheep, and all of 65 cysts from goats); the genotype G6 was identified by sequencing 13 of these isolates. Only 2 cysts from cattle belonged to Echinococcus ortleppi. The mean number of cysts per infected animal was much higher in camels (5.1) than in the other species (1.0-1.3), and cyst fertility was higher in camels and cattle (74% and 77%) than in goats and sheep (31% and 19%). Fertile cysts from five human patients from hospitals in Khartoum and Juba belonged to E. canadensis (G6). This study confirms the predominance of the 'camel strain' in Sudan and the infectivity of this strain for humans. This is the first genetic characterization of human CE in Sudan.
Veterinary Microbiology, 1996
The autotrophic ammonia-oxidizing bacteria in a eutrophic freshwater lake were studied over a 12-... more The autotrophic ammonia-oxidizing bacteria in a eutrophic freshwater lake were studied over a 12-month period. Numbers of ammonia oxidisers in the lakewater were small throughout the year, and tangential-flow concentration was required to obtain meaningful estimates of most probable numbers. Sediments from littoral and profundal sites supported comparatively large populations of these bacteria, and the nitrification potential was high, particularly in summer samples from the littoral sediment surface. In enrichment cultures, lakewater samples nitrified at low (0.67 mM) ammonium concentrations only whereas sediment samples exhibited nitrification at high (12.5 mM) ammonium concentrations also. Enrichments at low ammonium concentration did not nitrify when inoculated into high-ammonium medium, but the converse was not true. This suggests that the water column contains a population of ammonia oxidizers that is sensitive to high ammonium concentrations. The observation of nitrification at high ammonium concentration by isolates from some winter lakewater samples, identified as nitrosospiras by 16S rRNA probing, is consistent with the hypothesis that sediment ammonia oxidizers enter the water column at overturn. With only one exception, nested PCR amplification enabled the detection of Nitrosospira 16S rDNA in all samples, but Nitrosomonas (N. europaea-eutropha lineage) 16S rDNA was never obtained. However, the latter were part of the sediment and water column communities, because their 16S rRNA could be detected by specific oligonucleotide probing of enrichment cultures. Furthermore, a specific PCR amplification regime for the Nitrosomonas europaea ammonia monooxygenase gene (amoA) yielded positive results when applied directly to sediment and lakewater samples. Patterns of Nitrosospira and Nitrosomonas detection by 16S rRNA oligonucleotide probing of sediment enrichment cultures were complex, but lakewater enrichments at low ammonium concentration were positive for nitrosomonads and not nitrosospiras. Analysis of enrichment cultures has therefore provided evidence for the existence of subpopulations within the lake ammonia-oxidizing community distinguishable on the basis of ammonium tolerance and possibly showing a seasonal distribution between the sediment and water column.
Preventive Veterinary Medicine, 1995
Six calves were immunized with whole egg antigen of Schistosoma bovis emulsified in Freund's adju... more Six calves were immunized with whole egg antigen of Schistosoma bovis emulsified in Freund's adjuvant. The immune response was monitored by agar-gel immunodiffusion (AGID) and enzyme-linked immunosorbent assay (ELISA). Using AGID and ELISA, antibodies to whole egg antigen were detected in sera from all immunized calves, but not in sera from control calves. The immunized calves and six control calves were challenged 6 montlhs after the beginning of the immunization with 20 000 cercariae of Schistosoma bovis administered percutaneously to the shaved tail. There was no significant difference between the immunized and the control calves as judged by fecal and tissue egg counts, worm recovery and hematological parameters. There was a lack of association between antibody production and protection. * Corre!;ponding author. 0167-5877/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDZO167-5877(94)00385-V
Vaccine, 1995
ARADAIB, I., R. OMER, A. MAJID: Kinetics of antibody response of calves immunized with Schistosom... more ARADAIB, I., R. OMER, A. MAJID: Kinetics of antibody response of calves immunized with Schistosoma mansoni glutathione-S-transferase. Vet. arhiv 73, 17-25, 2003.
Preventive Veterinary Medicine, 1995
Bovine schistosomosis, caused by Schistosoma bovis, constitutes a serious veterinary problem in m... more Bovine schistosomosis, caused by Schistosoma bovis, constitutes a serious veterinary problem in many parts of the world. The vaccination approaches for the control of bovine schistosomosis include the use of irradiation-attenuated S. bovis cercarial or schistosomular vaccines, S. bovis adult worms or whole-egg antigens and defined antigen vaccine. Irradiated S. bovis cercarial or schistosomular vaccines provide partial protection against S. bovis intkction. However, this type of vaccine requires live infectious cercariae or viable schistosomula for induction of protection. Unfortunately, experimental immunizations with dead schistosome antigens have been largely unsuccessful. The surge of new techniques in cellular immunology and molecular biology has made possible the development of potential candidate vaccine antigens from various species of schistosomes including S. bovis. The efficiency of these vaccines has been evaluated in experimentally infected calves.
Comparative Immunology Microbiology and Infectious Diseases, 2003
Comparative Immunology Microbiology and Infectious Diseases, 1997
The interaction of epizootic hemorrhagic disease virus (EHDV) with bovine erythrocytes in t'itro ... more The interaction of epizootic hemorrhagic disease virus (EHDV) with bovine erythrocytes in t'itro has been studied, and the results are presented herein. EHDV, a member of the Orbit, irus genus in the family Reoviridae, causes fatal hemorrhagic disease in North American white-tailed deer (Odocoileus virginianus). Other captive and free ranging ruminants may also be infected with the disease [1,. At least 10 serotypes of EHDV are recognised worldwide, but serotypes 1 and 2 are enzootic in the United States. In white-tailed deer, viremia is short and the disease usually follows a peracute course leading to death. In cattle, EHDV infection is common but typically asymptomatic, and viremia in EHDV infected cattle is usually short. However, infection of European breed of cattle with laboratory adapted strain of EHDV induced viremia which persisted for up to 50 days , suggesting that cattle may play a role in the epidemiology of the disease [2]. During the later course of EHDV-infection, the virus is principally associated with erythrocytes. Erythrocyte-associated viremia has been reported with a number of orbiviruses including bluetongue virus (BTV); however, there is no information available on the interaction of EHDV with bovine erythrocytes. The mechanism involved in prolonged viremia in EHDV-infected cattle, despite the presence of circulating neutralising antibodies, has yet to be explained. A plaque-purified EHDV serotype 1 (New Jersey strain) was used to inoculate suspended bovine erythrocytes, obtained from 4-month-old calves, at a multiplicity of infection (MOI) of 1, and the inoculated erythrocytes were incubated at 37~>C for 1 h. Uninoculated erythrocytes were used as controls. The details for collection of blood, preparation of erythrocytes, preparation of sections for transmission electron microscope were described previously .
Veterinary Microbiology, 1998
A nested polymerase chain reaction (PCR)-based assay, for detection of bluetongue virus (BTV) rib... more A nested polymerase chain reaction (PCR)-based assay, for detection of bluetongue virus (BTV) ribonucleic acid in cell culture and tissue samples, was developed. Two pairs of oligonucleotide primers (BTV1 and BTV4 and BTV2 and BTV3), selected from non-structural protein 1 (NS1) gene of BTV-17, were used for the nested PCR in two amplification steps. First a 826-bp product was amplified using an outer primer pair BTV1 and BTV4. The second amplification, using nested or internal primer pair BTV2 and BTV3, produced a 517-bp PCR product. RNA from North American prototype serotypes 2, 10, 11, 13 and 17, propagated in cell cultures, were detected by this nested PCR-based assay. The nested primers BTV2 and BTV3 increased the sensitivity of the BTV PCR assay, and as little as 0.1 fg of BTV RNA (equivalent to 5 viral particles) could be detected. Amplification products were not detected when the PCR-based assay was applied to RNA from a closely related orbivirus, epizootic hemorrhagic disease virus (EHDV) prototype serotypes 1 and 2; total nucleic acid extracts from uninfected BHK-21 cells; or whole blood from calves and deer that were BTV-seronegative and virus isolation negative. Application of this nested BTV PCR-based assay to clinical samples resulted in detection of BTV RNA from a variety of tissues collected from calves and deer with natural and experimental BTV infections. The described BTV PCR-based assay provides a valuable tool to study the epidemiology of BTV infection in susceptible wild ruminants and domestic livestock.
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Papers by Imadeldin Aradaib