Faezeh Najafi, Maede Taghavi Ghadikolai, Saied Reza Naddaf, Hamid Hasanpour, Iraj Mobedi, Gholamreza Mowlavi,
Volume 5, Issue 1 (1-2017)
Abstract
Introduction: Some postgraduate students reported the presence of a nematode infection, presumably, Trichosomoides crassicauda in the urinary bladder of rats (Rattus norvegicus) from the animal house of Tehran University of Medical Sciences (TUMS). We prompted to explore the prevalence of this infection among the rats of animal houses belonging to medical and veterinary research centers in Tehran. We also described the histopathological changes in the bladder tissue of the infected rats. Methods: We collected 214 adult rats (R. norvegicus) from four animal houses including TUMS in Tehran. The urine of 112 animals was collected during 24 h and inspected microscopically for helminths eggs. Then, the rats were euthanized, sacrificed and dissected; their bladders were removed and examined under a stereomicroscope for the presence of worms and histopathological changes. Results: Out of 112 urine samples checked, 16 contained T. crassicauda eggs. Out of 214 rats, 114 showed infection urinary bladder with the nematode T. crassicauda. The histopathological changes in the urinary bladder included hyperemia, edema, hyperplasia, and metaplasia. In the transitional epithelium, the features of gravid female nematodes, with an egg-filled uterus were visible. Conclusion: Trichosomoides crassicauda is a prevalent infection in laboratory rats of research centers in Tehran and its identification cannot be made merely based on urine examination of the rats.
Mehdi Rahpeyma, Rouzbeh Bashar,
Volume 9, Issue 1 (3-2021)
Abstract
Introduction: Rabies is a zoonotic fatal viral disease caused by the rabies virus of the genus Lyssavirus, and the family Rhabdoviridae. Challenge virus standard (CVS-11) strain of rabies virus is a key element in rabies reference laboratories, as many gold-standard tests depend on a suitable titer of this strain for interpretation of results. The present study investigated the optimal CVS-11 production in BSR cells (a clone of BHK-21). Methods: We analyzed the kinetic growth of BSR cells in a T-flask and inoculated BSR cells with different MOI of CVS-11 strain of rabies virus, and harvested the produced virus at different time points. Results: Our data showed that BSR cells had a doubling time of around 24-30 h, and at least 95% of cells kept their viability three days after culture. The virus reached the highest titer when the cells were infected at an MOI of 0.1 in DMEM medium, equal to 1.5 × 107 fluorescent focus units (FFU)/ml. Time-course analysis of CVS-11 titer showed that the highest titer was achieved around 72 h post-infection. All tests were performed in triplicate. Conclusion: Since producing the virus in mammalian cell culture is an expensive and complicated method, optimizing the virus production process may be an excellent strategy to lower the cost, save the laboratory resources and maximize productivity.
