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result(s) for
"Kasem, Samy"
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Isolation, molecular characterization, and genetic diversity of recently isolated foot-and-mouth disease virus serotype A in Egypt
2023
Foot-and-mouth Disease (FMD) is a highly contagious viral disease affecting all hoof-cloven animals. Serotypes A, O and SAT 2 of the foot-and-mouth disease virus (FMDV) are circulating in Egypt. The present study aimed to identify and molecularly characterize the FMDV strains circulating in Northern Egypt during an epidemic that struck the nation in 2022. RNA was extracted from the epithelial specimens, vesicular fluid from affected cattle. The samples were screened using real-time reverse-transcription polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene. Positive samples underwent individual serotype-specific amplification using primers designed for VP1 of O, A, and SAT 2 serotypes. Subsequently, direct sequencing was performed on the positive samples. The real-time RT-PCR detected positive samples from epithelial and vesicular fluid samples, but not in the blood of infected animals. Out of the 16 samples, seven tested positive for FMDV serotype A. Of these seven positive samples, six were categorized as serotype A-African topotype-G-IV, and these positive samples were isolated in BHK-21 cells, yielding an overt cytopathic effect caused by the virus. In conclusion, it is necessary to sustain continuous surveillance of the evolution of circulating FMDV strains to facilitate the assessment and aid in the selection of vaccine strains for the effective control of FMDV in Egypt.
Journal Article
Humoral Immunogenicity and Efficacy of a Single Dose of ChAdOx1 MERS Vaccine Candidate in Dromedary Camels
by
Alharbi, Naif Khalaf
,
Aldubaib, Musaad
,
Temperton, Nigel J.
in
45/77
,
631/250/590
,
631/326/596/2563
2019
MERS-CoV seronegative and seropositive camels received a single intramuscular dose of ChAdOx1 MERS, a replication-deficient adenoviral vectored vaccine expressing MERS-CoV spike protein, with further groups receiving control vaccinations. Infectious camels with active naturally acquired MERS-CoV infection, were co-housed with the vaccinated camels at a ratio of 1:2 (infected:vaccinated); nasal discharge and virus titres were monitored for 14 days. Overall, the vaccination reduced virus shedding and nasal discharge (p = 0.0059 and p = 0.0274, respectively). Antibody responses in seropositive camels were enhancedby the vaccine; these camels had a higher average age than seronegative. Older seronegative camels responded more strongly to vaccination than younger animals; and neutralising antibodies were detected in nasal swabs. Further work is required to optimise vaccine regimens for younger seronegative camels.
Journal Article
Isolation, molecular characterization, and genetic diversity of recently isolated foot-and-mouth disease virus serotype A in Egypt
2023
Foot-and-mouth Disease (FMD) is a highly contagious viral disease affecting all hoof-cloven animals. Serotypes A, O and SAT 2 of the foot-and-mouth disease virus (FMDV) are circulating in Egypt. The present study aimed to identify and molecularly characterize the FMDV strains circulating in Northern Egypt during an epidemic that struck the nation in 2022. RNA was extracted from the epithelial specimens, vesicular fluid from affected cattle. The samples were screened using real-time reverse-transcription polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene. Positive samples underwent individual serotype-specific amplification using primers designed for VP1 of O, A, and SAT 2 serotypes. Subsequently, direct sequencing was performed on the positive samples. The real-time RT-PCR detected positive samples from epithelial and vesicular fluid samples, but not in the blood of infected animals. Out of the 16 samples, seven tested positive for FMDV serotype A. Of these seven positive samples, six were categorized as serotype A-African topotype-G-IV, and these positive samples were isolated in BHK-21 cells, yielding an overt cytopathic effect caused by the virus. In conclusion, it is necessary to sustain continuous surveillance of the evolution of circulating FMDV strains to facilitate the assessment and aid in the selection of vaccine strains for the effective control of FMDV in Egypt.
Journal Article
Nationwide Seroprevalence of Coxiella burnetii Infection in Saudi Farm Animals: Implications for Public Health
2025
Q fever, caused by the intracellular bacterium Coxiella burnetii, is a significant zoonotic disease for which ruminants are the main reservoir. This cross-sectional study aimed to assess the seroprevalence of C. burnetii in farm animals (sheep, goats, cattle, and camels) across Saudi Arabia. A total of 7760 serum samples were collected from 2253 sheep, 2224 goats, 1111 cattle, and 2172 camels, representing various regions of the country. The samples were screened for C. burnetii antibodies using an enzyme-linked immunosorbent assay (ELISA). The findings revealed significant regional and species-specific differences. The findings revealed notable regional and species-specific variations in seroprevalence. In goats, seropositivity was detected in 92% of the tested herds; however, only 48% of the individually tested animals were found to be positive. Similarly, camels exhibited herd-level seropositivity of 92.9% of the examined herds, with only 46.7% of the individually examined animals testing positive. For sheep, 80% of the examined sheep flocks were positive, while 30.2% of the individually tested animals were positive. Cattle showed a significantly lower seroprevalence, since only 27.6% of the screened herds were found to be positive, and only 8.2% of the individually tested animals were positive. In conclusion, the results indicate that C. burnetii infection is widespread among livestock in Saudi Arabia, with goats, camels, and sheep posing a particularly elevated risk of zoonotic transmission. The observed regional disparities and species-specific infection rates highlight the need for comprehensive surveillance and targeted control strategies to mitigate the spread of Q fever in Saudi Arabia.
Journal Article
Full-length genome reveals genetic diversity and extensive recombination patterns of Saudi GI-1 and GI-23 genotypes of infectious bronchitis virus
2025
Background
Despite numerous genetic studies on Infectious Bronchitis Virus (IBV), many strains from the Middle East remain misclassified or unclassified. Genotype 1 (GI-1) is found globally, while genotype 23 (GI-23) has emerged as the predominant genotype in the Middle East region, evolving continuously through inter- and intra-genotypic recombination. The GI-23 genotype is now enzootic in Europe and Asia.
Methods
Over a 24-month period from May 2022 to June 2024, 360 samples were collected from 19 layer and 3 broiler poultry farms in central Saudi Arabia. The chickens exhibited reduced laying rates and symptoms such as weakness and respiratory distress, while broilers showed respiratory issues. Samples, including tracheal swabs and various tissue specimens, were pooled, homogenized, and stored at -20 °C prior to PCR analysis. The samples underwent virus isolation in embryonated chicken eggs, RNA extraction using automated systems, and detection of IBV through real-time RT-PCR targeting a conserved 5’-UTR fragment. Full-length genome sequencing was performed, and recombination analysis was conducted using RDP 4.6.
Results
Saudi IBV strains were found to cluster into genotypes GI-1 and GI-23.1. The study identified critical amino acid substitutions in the hypervariable regions of the spike protein and detected recombination events in the ORF1ab, N, M, 3ab, and 5ab genes, with nsp3 of the ORF1ab showing the greatest number of recombination events.
Conclusion
The multiple inter- and intra-genotypic recombination events that were detected in different genes indicate that the circulating IBV strains do not share a single ancestor but have emerged through successive recombination events.
Journal Article
Correction: Full-length genome reveals genetic diversity and extensive recombination patterns of Saudi GI-1 and GI-23 genotypes of infectious bronchitis virus
by
Haridy, Mohei A.
,
Albaqshi, Hassan A.
,
Aljasem, Yahya K.
in
Biomedical and Life Sciences
,
Biomedicine
,
Correction
2025
Journal Article
Comprehensive Serology Based on a Peptide ELISA to Assess the Prevalence of Closely Related Equine Herpesviruses in Zoo and Wild Animals
by
Wenker, Christian
,
Czirják, Gábor Á.
,
Abdelgawad, Azza
in
Animals
,
Animals, Wild - virology
,
Animals, Zoo - virology
2015
Equine herpesvirus type 1 (EHV-1) causes respiratory disorders and abortion in equids while EHV-1 regularly causes equine herpesvirus myeloencephalopathy (EHM), a stroke-like syndrome following endothelial cell infection in horses. Both EHV-1 and EHV-9 infections of non-definitive hosts often result in neuronal infection and high case fatality rates. Hence, EHV-1 and EHV-9 are somewhat unusual herpesviruses and lack strict host specificity, and the true extent of their host ranges have remained unclear. In order to determine the seroprevalence of EHV-1 and EHV-9, a sensitive and specific peptide-based ELISA was developed and applied to 428 sera from captive and wild animals representing 30 species in 12 families and five orders. Members of the Equidae, Rhinocerotidae and Bovidae were serologically positive for EHV-1 and EHV-9. The prevalence of EHV-1 in the sampled wild zebra populations was significantly higher than in zoos suggesting captivity may reduce exposure to EHV-1. Furthermore, the seroprevalence for EHV-1 was significantly higher than for EHV-9 in zebras. In contrast, EHV-9 antibody prevalence was high in captive and wild African rhinoceros species suggesting that they may serve as a reservoir or natural host for EHV-9. Thus, EHV-1 and EHV-9 have a broad host range favoring African herbivores and may have acquired novel natural hosts in ecosystems where wild equids are common and are in close contact with other perissodactyls.
Journal Article
Some pathological observations on the naturally infected dromedary camels (Camelus dromedarius) with the Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia 2018-2019
by
Hemida, Maged Gomaa
,
Al-Shabebi, Abdulkareem
,
Albadrani, Abdalaziz
in
Agglutination
,
agglutination tests
,
Animals
2020
The natural MERS-CoV infection in dromedary camels is understudied. Recent experimental studies showed no obvious clinical signs in the infected dromedary camels.
To study the pathological changes associated with natural MERS-CoV infection in dromedary camels.
Tissues from three MERS-CoV positive animals as well as two negative animals were collected and examined for the presence of pathological changes. The screening of the animals was carried out first by the rapid agglutination test and then confirmed by the RT-PCR. The selected animals ranged from six to twelve months in age. The sensitivity of the latter technique was much higher in the detection of MERS-CoV than the Rapid test (14 out of 75 animals positive or 18% versus 31 out of 75 positive or 41%).
MERS-CoV induced marked desquamation of the respiratory epithelium accompanied by lamina propria and submucosal mononuclear cells infiltration, epithelial hyperplasia in the respiratory tract, and interstitial pneumonia. Ciliary cell loss was seen in the trachea and turbinate. In addition, degeneration of glomerular capillaries with the complete destruction of glomerular tufts that were replaced with fibrinous exudate in renal corpuscles in the renal cortex were noticed. Expression of the MERS-CoV-S1 and MERS-CoV-N proteins was revealed in respiratory tract, and kidneys.
To our knowledge, this is the first study describing the pathological changes of MERS-CoV infection in dromedary camels under natural conditions. In contrast to experimental infection in case of spontaneous infection interstitial pneumonea is evident at least in some affected animals.
Journal Article
Challenge infection model for MERS-CoV based on naturally infected camels
by
Alharbi, Naif Khalaf
,
Aldubaib, Musaad
,
Aldowerij, Ali
in
Antibodies
,
Antiviral agents
,
Antiviral drugs
2020
Background
Middle East Respiratory Syndrome coronavirus (MERS-CoV) is an emerging virus that infects humans and camels with no approved antiviral therapy or vaccine. Some vaccines are in development for camels as a one-health intervention where vaccinating camels is proposed to reduce human viral exposure. This intervention will require an understanding of the prior exposure of camels to the virus and appropriate vaccine efficacy studies in camels.
Methods
We conducted a cross sectional seroprevalence study in young dromedary camels to determine the rate of MERS-CoV seropositivity in young camels. Next, we utilised naturally infected camels as a natural challenge model that can be used by co-housing these camels with healthy naive camels in a ratio of 1 to 2. This model is aimed to support studies on natural virus transmission as well as evaluating drug and vaccine efficacy.
Results
We found that 90% of the screened camels have pre-existing antibodies for MERS-CoV. In addition, the challenge model resulted in MERS-CoV transmission within 48 h with infections that continued for 14 days post challenge.
Conclusions
Our finding suggests that the majority of young dromedary camels in Saudi Arabia are seropositive and that naturally infected camels can serve as a challenge model to assess transmission, therapeutics, and vaccine efficacy.
Journal Article
Equine Herpesvirus Type 1 ORF76 Encoding US9 as a Neurovirulence Factor in the Mouse Infection Model
by
Nayel, Mohamed
,
Fukushi, Noriko
,
Elsify, Ahmed
in
Animals
,
Artificial chromosomes
,
Bacterial artificial chromosomes
2024
Equine herpesvirus type 1 (EHV-1) causes rhinopneumonitis, abortion, and neurological outbreaks (equine herpesvirus myeloencephalopathy, EHM) in horses. EHV-1 also causes lethal encephalitis in small laboratory animals such as mice and hamsters experimentally. EHV-1 ORF76 is a homolog of HSV-1 US9, which is a herpesvirus kinase. Starting with an EHV-1 bacterial artificial chromosome clone of neuropathogenic strain Ab4p (pAb4p BAC), we constructed an ORF76 deletion mutant (Ab4p∆ORF76) by replacing ORF76 with the rpsLneo gene. Deletion of ORF76 had no influence on replication, cell-to-cell spread in cultured cells, or replication in primary neuronal cells. In Western blots of EHV-1-infected cell lysates, an EHV-1 US9-specific polyclonal antibody detected multiple bands ranging from 35 to 42 kDa. In a CBA/N1 mouse infection model following intranasal inoculation, the parent and Ab4p∆ORF76 revertant caused the same histopathology in the brain and olfactory bulbs. The parent, Ab4p∆ORF76, and revertant mutant replicated similarly in the olfactory mucosa, although Ab4p∆ORF76 was not transported to the olfactory bulbs and was unable to infect the CNS. These results indicated that ORF76 (US9) plays an essential role in the anterograde spread of EHV-1.
Journal Article