This collection includes those samples coming from routine diagnostic activity which are considered valuable in terms of viral content. The reasons for which materials are conserved and included in the collection are basically due to their peculiarity as regard to species or type of virus detected. In fact, they are mostly rare, non-cultivable, uncommon, unidentified or potentially new viruses, often from minor species.
Indeed, they have all been characterized by electron microscopic observation. In fact, the viral positivity is intended as presence of virions ascertained by using negative staining electron microscopy as identification method.
Virion identification is based on morphology. Thus classification is not necessarily referable to a taxa (family, genus, species etc.) but is often defined with a “generic” name, that may be often related to their morphological aspect (presence of the suffix “–like” in the name).
In some cases, a better taxonomic identification (up to species or to strain definition) may be given if the examination has been done using an immune-electron-microscopy (IEM) method, i.e. by using specific “known” sera or antibodies in order to concentrate and aggregate virions in the form of immune-complexes.
Each pathological material not necessarily contains just one virus. In fact, it is not uncommon to detect two or more viruses in association, often acting in a synergic way, especially in intestinal contents/faeces.
Quality controls
The amount of virions present in each preparation may vary considerably. A semi-quantitative evaluation of the viral contents is always given during observation with reference to a scale of positivity ranging from 1 to 5 +.
In the collection the materials may be present in the form of raw material (as it has been sent to the laboratory) or in the form of supernatant from the centrifugation (6500rpm x 30 min) of the extract/homogenates (10% w/v in distilled water) prepared from the original materials.
Each sample included in the collection has the exact amount of available material expressed in gr or ml according to the relative form.
Quality management system
IZSLER laboratories, that supply biological resources to IBVR, use testing methods performed according to UNI EN ISO/IEC 17025 quality system. In addition, the EM laboratory is taking part since 2000 to an international quality ring test named External Quality Assessment (EQA) organized by Robert Koch institute – Berlin.
THE LIST OF AVAILABLE MATERIALS, ACTUALLY OVER 800, COULD BE OBTAINED BY DIRECTLY CONTACTING THE RESOURCE SPECIALIST (SUBSTR@IZSLER.IT; ENRICA.SOZZI@IZSLER.IT).
THEREAFTER, THE MATERIALS COULD BE FURNISHED BY ESTABLISHING A SCIENTIFIC COLLABORATION AND SIGNING AN MTA.
Updated to July 2022