Publications by authors named "Charifa Touzani"

3 Publications

  • Page 1 of 1

Pathogenesis of Avian Influenza Virus Subtype H9N2 in Turkeys and Evaluation of Inactivated Vaccine Efficacy.

Avian Dis 2021 03;65(1):46-51

Unité de Pathologie Aviaire, Département de Pathologie et Santé Publique Vétérinaire, Institut Agronomique et Vétérinaire Hassan II, Rabat, Morocco.

Avian influenza H9N2 viruses circulate in all types of poultry species, including turkeys, and cause significant losses for the poultry industry in many parts of the word. The aim of this study was to assess the pathogenesis of the Moroccan avian influenza virus (AIV) H9N2 under experimental conditions in turkeys and the protection efficacy of an inactivated commercial vaccine against AIV H9N2. Unvaccinated turkeys showed marked depression sinusitis, respiratory distress characterized by bronchiolar and tracheal rales of moderate severity, and a mortality rate of 50%. Postmortem examinations of dead and euthanatized birds revealed the presence of fibrinous tracheitis and airsacculitis lesions. Vaccination reduced the mortality rate to 20%. Vaccinated birds recovered at day 10 postchallenge, and only 12.5% (1/8) and 37.5% of birds still displayed fibrinous and nonfibrinous airsacculitis lesions, respectively, at day 15 postinoculation. Viral shedding in cloacal and tracheal swabs was lower in vaccinated than in control birds. Although viral RNA was detected in the cloacal swabs of all unvaccinated turkeys at day 3 postinoculation, only 50% of the vaccinated turkeys were positive for virus detection. At day 11 postinoculation, no viral RNA was detected in oropharyngeal swabs of vaccinated turkeys, whereas 40% of the unvaccinated turkeys were still shedding virus.
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http://dx.doi.org/10.1637/aviandiseases-D-20-00067DOI Listing
March 2021

First Report of Isolation of from Layer Chickens in Morocco with Decrease in Laying Performance.

Avian Dis 2019 12;63(4):727-730

Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Vienna 1210, Austria.

is a genus of the family of . It is well known as a commensal inhabitant of the respiratory and reproductive tract of healthy chickens. But in the last years, is increasingly reported in field cases with a decrease in laying performance due to infections of the reproductive tract. The aim of the present study was to investigate the implication of infection in layer flocks facing a decrease in laying performance in Morocco. Birds were received from five different laying hen farms in two regions in Morocco showing a drop of egg production. Necropsy revealed 46.1 % (24/52) of sampled birds showed variable lesions in ovaries, salpinx, and trachea. In fact, 24 birds were affected by salpingitis, 18 by oophoritis, and 11 birds by atrophy of ovaries. Furthermore, tracheitis was observed in 24 birds. Bacteriological investigation was done from different organs, and was found in ovaries ( = 20), trachea ( = 17), and cloaca ( = 3). Identification was based on growth morphology, Gram staining, and biochemical properties. Additionally, polymerase chain reaction test using specific primers for the genus identification was carried out. All isolates showed bands of 925 bp specific for expressing the virulent toxin GtxA. Antibiotic resistance testing was performed and revealed that isolates were sensitive to enrofloxacin, florfenicol, and gentamycin but resistant to ampicillin, erythromycin, oxytetracycline, and sulfamethoxazole-trimethoprim. The present study is the first report of in Morocco, demonstrating the need for further epidemiologic investigations as well as in regard to antibiotic resistance development.
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http://dx.doi.org/10.1637/aviandiseases-D-19-00119DOI Listing
December 2019

Co-infections of chickens with avian influenza virus H9N2 and Moroccan Italy 02 infectious bronchitis virus: effect on pathogenesis and protection conferred by different vaccination programmes.

Avian Pathol 2020 Feb 3;49(1):21-28. Epub 2019 Oct 3.

Université de Toulouse, ENVT, INRA, UMR IHAP, Toulouse, France.

Since the emergence of low pathogenic avian influenza (LPAI) H9N2 viruses in Morocco in 2016, severe respiratory problems have been encountered in the field. Infectious bronchitis virus (IBV) is often detected together with H9N2, suggesting disease exacerbation in cases of co-infections. This hypothesis was therefore tested and confirmed in laboratory conditions using specific-pathogen-free chickens. Most common field vaccine programmes were then tested to compare their efficacies against these two co-infecting agents. IBV γCoV/chicken/Morocco/I38/2014 (Mor-IT02) and LPAI virus A/chicken/Morocco/SF1/2016 (Mor-H9N2) were thus inoculated to commercial chickens. We showed that vaccination with two heterologous IBV vaccines (H120 at day one and 4/91 at day 14 of age) reduced the severity of clinical signs as well as macroscopic lesions after simultaneous experimental challenge. In addition, LPAI H9N2 vaccination was more efficient at day 7 than at day 1 in limiting disease post simultaneous challenge. Simultaneous challenge with IBV and AIV H9N2 induced higher pathogenicity in SPF birds than inoculation with IBV or AIV H9N2 alone.Recommended vaccination programme in commercial broilers to counter Mor-IT02 IBV and LPAIV H9N2 simultaneous infections: IB live vaccine H120 (d1), AIV H9N2 inactivated vaccine (d7), IB live vaccine 4-91 (d14).
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http://dx.doi.org/10.1080/03079457.2019.1656328DOI Listing
February 2020
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