Publications by authors named "Najete Safini"

5 Publications

  • Page 1 of 1

Biological and molecular characterization of a sheep pathogen isolate of and leukotoxin production kinetics.

Vet World 2021 Aug 7;14(8):2031-2040. Epub 2021 Aug 7.

Department of Microbiology, Immunology and Contagious Diseases, Institute of Agronomy and Veterinary Medicine Hassan II, Rabat, Morocco.

Background And Aim: (Mha) is a common agent of pneumonia in ruminants globally, causing economic losses by morbidity, mortality, and treatment costs. Infection by Mha is often associated with or promoted by respiratory viral pathogens and environmental conditions. Infections due to Mha have rarely been described in small ruminants. This study reports the biological and molecular characteristics of a new Moroccan Mha isolate from small ruminants presenting typical respiratory symptoms. We also studied the cultural parameters, growth kinetics, and Lkt excretion of the isolate and its pathogenicity on laboratory animals and small ruminants.

Materials And Methods: Suspected pasteurellosis cases in sheep and goat flocks in Morocco were investigated. A local strain of Mha was isolated and identified using biochemical and molecular methods. Polymerase chain reaction-targeting specific genes were used for serotyping and phylogenetic analyses; further, leukotoxin production, cytotoxicity, and pathogenicity of the isolate in mice, goats, and sheep were investigated.

Results: Phylogeny analysis revealed 98.76% sequence identity with the USA isolate of 2013; the strain growth with a cycle of 9-10 h with leukotoxin secretion was detected by NETosis and quantified by cytotoxicity and mortality of mice. Goat and sheep infections cause hyperthermia, with characteristic postmortem lesions in the trachea and lung.

Conclusion: A local isolate of Mha from sheep that died of pneumonia was characterized for the 1 time in North Africa using biological and molecular methods. Although growth on appropriate culture media is accompanied by intense leukotoxin secretion, experimental infections of sheep and goats cause hyperthermia and typical lesions of pneumonia.
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http://dx.doi.org/10.14202/vetworld.2021.2031-2040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8448628PMC
August 2021

Comparative sensitivity study of primary cells, vero, OA3.Ts and ESH-L cell lines to lumpy skin disease, sheeppox, and goatpox viruses detection and growth.

J Virol Methods 2021 07 14;293:114164. Epub 2021 Apr 14.

Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810 Mohammedia, Morocco.

Lumpy skin disease virus (LSDV), sheeppox virus (SPPV) and goatpox (GTPV) virus have been usually grown on primary cells for diagnosis, production and titration purposes. The use of primary cells present several inconvenient, heavy preparation, heterogeneous cell population, non-reproducible viral titration and presence of potential endogenous contaminants. Therefore investigating sensitivity of candidate continuous cell lines is needed. In this study, we compared the above Capripox viruses (CaPVs) sensitivity of primary cells of four origin (heart, skin, testis and kidney), with three cell lines (Vero, OA3.Ts and ESH-L). We tested sensitivity for virus isolation, replication cycle and titration, revealed by cytopathic effect (CPE), immunoenzymatic staining and immunofluorescence. Our results show that ESH-L cells and primary fetal heart cells present the highest sensitivity for CaPVs growth and detection. Vero cells can replicate those viruses but without showing any CPE while the titer obtained on OA3.Ts is lower than primary and ESH-L cells. ESH-L cells are an effective alternative to primary cells use for growing Capripoxviruses and their diagnosis.
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http://dx.doi.org/10.1016/j.jviromet.2021.114164DOI Listing
July 2021

Development of an inactivated combined vaccine for protection of cattle against lumpy skin disease and bluetongue viruses.

Vet Microbiol 2021 May 23;256:109046. Epub 2021 Mar 23.

Research and Development, MCI Santé Animale, ZI Sud-Ouest B.P: 278, Mohammedia, 28810, Morocco.

Lumpy Skin Disease (LSD) and Bluetongue (BT) are the main ruminants viral vector-borne diseases. LSD is endemic in Africa and has recently emerged in Europe and central Asia as a major threat to cattle industry. BT caused great economic damage in Europe during the last decade with a continuous spread to other countries. To control these diseases, vaccination is the only economically viable tool. For LSD, only live-attenuated vaccines (LAVs) are commercially available, whilst for BT both LAVs and inactivated vaccines are available with a limited number of serotypes. In this study, we developed an inactivated, oil adjuvanted bivalent vaccine against both diseases based on LSDV Neethling strain and BTV4. The vaccine was tested for safety and immunogenicity on cattle during a one-year period. Post-vaccination monitoring was carried out by VNT and ELISA. The vaccine was completely safe and elicited high neutralizing antibodies starting from the first week following the second injection up to one year. Furthermore, a significant correlation (R = 0.9040) was observed when comparing VNT and competitive ELISA in BTV4 serological response. Following BTV4 challenge, none of vaccinated and unvaccinated cattle were registered clinical signs, however vaccinated cattle showed full protection from viraemia. In summary, this study highlights the effectiveness of this combined vaccine as a promising solution for both LSD and BT control. It also puts an emphasis on the need for the development of other multivalent inactivated vaccines, which could be greatly beneficial for improving vaccination coverage in endemic countries and prophylaxis of vector-borne diseases.
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http://dx.doi.org/10.1016/j.vetmic.2021.109046DOI Listing
May 2021

Production of small ruminant morbillivirus, rift valley fever virus and lumpy skin disease virus in CelCradle™ -500A bioreactors.

BMC Vet Res 2021 Feb 27;17(1):93. Epub 2021 Feb 27.

Laboratory of Research and Development virology, MCI Animal Health, Lot. 157, Zone Industrielle Sud-Ouest (ERAC) B.P: 278, 28810, Mohammedia, Morocco.

Background: Animal vaccination is an important way to stop the spread of diseases causing immense damage to livestock and economic losses and the potential transmission to humans. Therefore effective method for vaccine production using simple and inexpensive bioprocessing solutions is very essential. Conventional culture systems currently in use, tend to be uneconomic in terms of labor and time involved. Besides, they offer a limited surface area for growth of cells. In this study, the CelCradle™-500A was evaluated as an alternative to replace conventional culture systems in use such as Cell factories for the production of viral vaccines against small ruminant morbillivirus (PPR), rift valley fever virus (RVF) and lumpy skin disease virus (LSD).

Results: Two types of cells Vero and primary Lamb Testis cells were used to produce these viruses. The study was done in 2 phases as a) optimization of cell growth and b) virus cultivation. Vero cells could be grown to significantly higher cell densities of 3.04 × 10 using the CelCradle™-500A with a shorter doubling time as compared to 9.45 × 10 cells in Cell factories. This represents a 19 fold increase in cell numbers as compared to seeding vs only 3.7 fold in Cell factories. LT cells achieved modestly higher cell densities of 6.7 × 10 as compared to 6.3 × 10 in Cell factories. The fold change in densities for these cells was 3 fold in the CelCradle™-500A vs 2.5 fold in Cell factories. The titers in the conventional system and the bioreactor were not significantly different. However, the Cell-specific virus yield for rift valley fever virus and lumpy skin disease virus are higher (25 virions/cell for rift valley fever virus, and 21.9 virions/cell for lumpy skin disease virus versus 19.9 virions/cell for rift valley fever virus and 10 virions/cell for lumpy skin disease virus).

Conclusions: This work represents a novel study for primary lamb testis cell culture in CellCradle™-500A bioreactors. In addition, on account of the high cell densities obtained and the linear scalability the titers could be further optimized using other culture process such us perfusion.
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http://dx.doi.org/10.1186/s12917-021-02801-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7913422PMC
February 2021

Dual role of dextran sulfate 5000 Da as anti-apoptotic and pro-autophagy agent.

Mol Biotechnol 2013 Jun;54(2):711-20

International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.

Dextran sulfate 5,000 Da (DS), a sulfated polysaccharide, has been used in recombinant mammalian cell cultures to prevent cell aggregation, thereby increasing cell viability. Previous studies using Chinese hamster ovary (CHO) suspension cultures had shown that low concentrations of DS are related to an inhibition of apoptosis. In this study, DS was used on anchorage-dependent CHO cells producing erythropoietin (EPO), in order to investigate the effect of this molecule on anti-apoptotic and pro-survival cellular pathways. DS 5,000 Da treatment was shown to prolong the life of cells and increase productivity of EPO by 1.8-fold comparing with controls, in standard batch conditions. At a molecular level, we show that DS inhibits apoptosis by DNA fragmentation delay and decrease of annexin V-labeled cells, causes a G0/G1 cell cycle arrest, decreases p53 expression and increases the pro-survival factor Hsc70 expression. DS treatment also resulted in an enhanced LC3-I to LC3-II conversion and increased autophagosomes formation employing tagged-LC3. Our data show, for the first time, that low doses of DS may promote autophagy in different cell lines. These findings suggest that a better understanding and manipulation of phenomenon of autophagy could be of crucial importance in the bio-pharmaceutical industry, in particular in the field of protein production.
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http://dx.doi.org/10.1007/s12033-012-9620-xDOI Listing
June 2013
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