AHMED HASSAN OMAR

Dr. AHMED HASSAN OMAR

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 May 2023 in Animals
Verified
Journal Article
Open access
PDF file
GLGianvito Lanave
Gianvito Lanave
ABAlessio Buonavoglia
Alessio Buonavoglia
FPFrancesco Pellegrini
Francesco Pellegrini
BMBarbara Di Martino
Barbara Di Martino
FPFederica Di Profio
Federica Di Profio
MCMichele Camero
Michele Camero
Feline calicivirus (FCV) is a common viral pathogen found in domestic cats. FCV is highly contagious and demonstrates a high genetic variability. Upper respiratory tract disease, oral ulcerations, salivation, and gingivitis–stomatitis have been regarded as typical clinical signs of FCV infection. Ulcerative dermatitis, abortion, severe pneumonia, enteritis, chronic stomatitis, and virulent systemic disease have been reported more sporadically. Limping syndrome has been also described either in naturally or experimentally FCV-infected cats. In this study, we monitored a small outbreak of FCV infection in two household cats, in which limping disease was monitored with a 12-day lag time. The complete genome sequence was determined for the viruses isolated from the oropharyngeal and rectal swabs of the two animals, mapping up to 39 synonymous nucleotide mutations. The four isolates were sensitive to low pH conditions and trypsin treatment, a pattern usually associated with viruses isolated from the upper respiratory tract. Overall, the asynchronous pattern of infections and the results of genome sequencing suggest that a virus of respiratory origin was transmitted between the animals and that the FCV strain was able to retain the limping disease pathotype during the transmission chain, as previously observed in experimental studies with FCV strains associated with lameness.

29 June 2023 in Antibiotics
Verified
Journal Article
Open access
PDF file
MGMichela Galgano
Michela Galgano
FPFrancesco Pellegrini
Francesco Pellegrini
DMDaniela Mrenoshki
Daniela Mrenoshki
PCPaolo Capozza
Paolo Capozza
AOAHMED HASSAN OMAR
AHMED HASSAN OMAR
ABAlessio Buonavoglia
Alessio Buonavoglia
The overuse and misuse of antibiotics can pose the risk of spreading mutant strains that show antimicrobial resistance (AMR), with negative impacts on the management of bacterial infections and economic implications for healthcare systems. The research and development of natural antibacterial agents could be a priority in the next years to improve a number of effective antibacterial molecules and to reduce the AMR phenomenon and its development. The present study identified the most effective concentration and contact time of Thymus vulgaris L. essential oil (TEO) to obtain bactericidal effects in vitro against different Gram-positive and Gram-negative bacterial strains. Six clinically isolated (wild types) bacterial strains, (Citrobacter freundii, Enterococcus feciorum, Proteus mirabilis, Acinetobacter cioffi, Pseudomonas putrefaciens and Klebsiella pneumoniae) and two ATCCs (Staphylococcus aureus and Streptococcus mutans) were tested after 1 min, 3 min and 5 min of contact with TEO. The preliminary results on S. aureus after 24 h of incubation revealed a TEO concentration of 9.28 mg/mL (w/v) that completely inhibited bacteria growth, keeping cell viability. The total suppression of bacterial growth at all tested contact times was observed for all tested bacterial strains, and the results were confirmed after 48 h of incubation. Bacterial growth suppression was confirmed even with the presence of organic components. These preliminary results showed the in vitro antimicrobial efficacy of TEO against different Gram-positive and Gram-negative bacterial strains. Future studies are necessary to confirm the reproducibility of these results even on other strains and to define the exact molecular mechanisms of EOs in order to consider TEO as a valid alternative to classic antibiotic therapies and subsequently to reduce the occurrence of AMR.

24 March 2023 in Animals
Verified
Journal Article
Open access
PDF file
FPFrancesco Pellegrini
Francesco Pellegrini
ABAlessio Buonavoglia
Alessio Buonavoglia
AOAHMED HASSAN OMAR
AHMED HASSAN OMAR
GDGeorgia Diakoudi
Georgia Diakoudi
MLMaria Stella Lucente
Maria Stella Lucente
GLGianvito Lanave
Gianvito Lanave
Massive sequencing techniques have allowed us to develop straightforward approaches for the whole genome sequencing of viruses, including influenza viruses, generating information that is useful for improving the levels and dimensions of data analysis, even for archival samples. Using the Nanopore platform, we determined the whole genome sequence of an H3N8 equine influenza virus, identified from a 2005 outbreak in Apulia, Italy, whose origin had remained epidemiologically unexplained. The virus was tightly related (>99% at the nucleotide level) in all the genome segments to viruses identified in Poland in 2005–2008 and it was seemingly introduced locally with horse trading for the meat industry. In the phylogenetic analysis based on the eight genome segments, strain ITA/2005/horse/Bari was found to cluster with sub-lineage Florida 2 in the HA and M genes, whilst in the other genes it clustered with strains of the Eurasian lineage, revealing a multi-reassortant nature.

24 November 2023 in Veterinary Sciences
Verified
Journal Article
Open access
PDF file
PCPaolo Capozza
Paolo Capozza
FPFrancesco Pellegrini
Francesco Pellegrini
MCMichele Camero
Michele Camero
GDGeorgia Diakoudi
Georgia Diakoudi
AOAHMED HASSAN OMAR
AHMED HASSAN OMAR
GLGianvito Lanave
Gianvito Lanave
A 3-year-old female stray, shorthair cat, with clinical signs and serum chemistry markers indicative of hepatic disease, was diagnosed with domestic cat hepadnavirus (DCH) infection. Coupling molecular and serological data, the infection was seemingly contextualized into a chronic phase, since IgM anti-core antibodies, a marker of early-stage Hepatitis B Virus (HBV) infection, were not detected. However, the cat possessed IgG anti-core, a common indicator of chronic HBV infection in human patients and did not show seroconversion to the anti-DCH surface antigen, considered protective during HBV infection and associated with long-term protective immunity. On genome sequencing, the DCH strain showed 98.3% nucleotide identity to strains previously identified in Italy.

25 May 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
MGMichela Galgano
Michela Galgano
FPFrancesco Pellegrini
Francesco Pellegrini
DMDaniela Mrenoshki
Daniela Mrenoshki
PCPaolo Capozza
Paolo Capozza
AOAHMED HASSAN OMAR
AHMED HASSAN OMAR
ABAlessio Buonavoglia
Alessio Buonavoglia
Overuse and misuse of antibiotics can pose the risks of spreading mutant strains that show antimicrobial resistance (AMR), with negative impact on management of bacterial infections and economic implications on healthcare systems. Research and development of natural antibacterial agents could be a priority in the next years to improve number of effective antibacterial molecules and to reduce AMR phenomenon and its development. The present study identified the most effective concentration and contact time of Thymus vulgaris L. essential oil (TEO) to obtain bactericidal effect in vitro against different Gram + and Gram – bacterial strains. Six clinically isolated (wild types) bacterial strains, (Citrobacter freundii, Enterococcus feciorum, Proteus mirabilis, Acinetobacter cioffi, Pasteurella putrefaciens, Klebsiella pneumoniae) and two ATCC (Staphylococcus aureus and Streptococcus mutans) were tested after 1min, 3min and 5min of contact with TEO. Preliminary results on S. aureus after 24h incubation revealed a TEO concentration of 9.28mg/mL (w/v) that completely inhibited bacteria growth keeping cell viability. Total suppression of bacterial growth at all tested contact times was observed for all tested bacterial strains and the results were confirmed after 48h incubation. Bacterial growth suppression was confirmed even with presence of organic component. These preliminary results showed in vitro antimicrobial efficacy of TEO against different Gram+ and Gram- bacterial strains. Future studies are necessary to confirm the reproducibility of these results even on other strains and to define exactly the molecular mechanisms of EOs, in order to consider TEO as a valid alternative of classic antibiotic therapies and subsequently to reduce the occurrence of AMR.

12 December 2022 in Pathogens
Verified
Journal Article
Open access
PDF file
FPFrancesco Pellegrini
Francesco Pellegrini
AOAHMED HASSAN OMAR
AHMED HASSAN OMAR
CBCanio Buonavoglia
Canio Buonavoglia
Annamaria PratelliAnnamaria Pratelli
Annamaria Pratelli
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), emerged in Wuhan city (Hubei province, China) in December 2019, and the World Health Organization (WHO) declared an international public health emergency on 11 March 2020