The True Host/s of Picobirnaviruses

Picobirnaviruses (PBVs) are bisegmented double-stranded RNA viruses that have been detected in a wide variety of animal species including invertebrates and in environmental samples. Since PBVs are ubiquitous in feces/gut contents of humans and other animals with or without diarrhea, they were considered as opportunistic enteric pathogens of mammals and avian species. However, the virus remains to be propagated in animal cell cultures, or in gnotobiotic animals. Recently, the classically defined prokaryotic motif, the ribosomal binding site sequence, has been identified upstream of putative open reading frame/s in PBV and PBV-like sequences from humans, various animals, and environmental samples, suggesting that PBVs might be prokaryotic viruses. On the other hand, based on the detection of some novel PBV-like RNA-dependent RNA polymerase sequences that use the alternative mitochondrial genetic code (that of mold or invertebrates) for translation, and principal component analysis of codon usage bias for these sequences, it has been proposed that PBVs might be fungal viruses with a lifestyle reminiscent of mitoviruses. These contradicting observations warrant further studies to ascertain the true host/s of PBVs, which still remains controversial. In this minireview, we have focused on the various findings that have raised a debate on the true host/s of PBVs.

In vitro food production from animal cell cultures as a meat alternative (selected legal aspects)

From a legal point of view, there may be doubts as to the legal qualification of food obtained in vitro from animal cells. An opinion is expressed in the article that meat from animal cells obtained using the in vitro method does not fall within the classical legal concepts of meat or agricultural production. However, meat products from cells produced by the in vitro method may satisfy the criteria established for novel food. If this is considered to be the correct way of qualification, then they should be subject to the EU market authorisation procedure regulated in Regulation 2015/2283, and a subsequent assessment of their safety. From a legal, economic and social point of view, it is reasonable to produce food using atypical methods if these methods are capable of ensuring food safety.

Molecular genetic techniques and oligonucleotides for mycoplasma identification – a review

Control of distribution of mycoplasmal infections in cattle herds is essential in the majority of countries world-wide. Various PCR procedures are available to detect mycoplasmas in cell cultures and bovine mycoplasma in different types of samples. We reviewed some common PCR techniques and specific primers targeted to different bacterial genetic regions of mycoplasma. Several researchers used the same PCR approach and Mycoplasma spp. as a target but their results could not be compared because different primer pairs were used. These methods and primers were first developed to identify mycoplasma species that contaminate animal cell cultures, and then were used by other researchers to differentiate mycoplasmas as a cow infecting agent. Our analysis of the specificity of these primer pairs to nucleotide sequences of five Mycoplasma spp. showed that oligonucleotides have less specificity to them. Numerous commercially available PCR kits are applicable to find mycoplasma contamination in cell cultures and fewer of them can be used in veterinary diagnostics. Although serological and culture techniques are still used, it is necessary to develop a new multiplex PCR technique with a more specific primer set especially in agrarian countries.

Synthesis of DEAE-Soybean Starch Microspheres for Adhere Animal Cell Culture

The present study outlines the synthesis of a new microcarrier for anchorage-dependent animal cell cultures. The new microcarriers were synthesized from the cross-linking soybean starch microspheres followed by modification with 2-diethylaminoethyl (DEAE). Furthermore, 5 g/100 mL of wet microspheres DEAE-soybean starch microspheres were applied in the adhere cell culture, with an inoculation density 2.0 × 105 cells/mL of BHK-21, Marc-145, and MDCK cells. The cells were shown to grow well in the DEAE-soybean starch microcarrier, with BHK-21 cells showing a higher cell density after 144 h (2.5 × 106 cells/mL) compared to cells grown on the commercial product Cytodex 1 (2.2 × 106 cells/mL). These starch microcarriers have a potential application in anchorage-dependent animal cells culture, due to its low cost and its simple process.