Detection and identification of the atypical bovine pestiviruses in commercial foetal bovine serum batches

Milk whey as a sustainable alternative growth supplement to fetal bovine serum in muscle cell culture

In vitro meat cultivation, a cutting-edge innovation in food science, may represent a more sustainable and ethical source of animal proteins compared with conventionally grown meat. An important challenge for meat cultivation lies in eliminating the use of fetal bovine serum (FBS) in cell culture media due to ethical concerns. Milk whey is a nutrient-rich liquid portion of the milk, derived as a byproduct of dairy industry. Similar to FBS, whey contains proteins that are crucial for nutrition, cell adhesion, and biomolecular transport. In this study, we investigated whether whey proteins (WP) can replace FBS in supporting muscle cell cultivation, using the C2C12 myoblast model. Accordingly, under serum-free conditions, cells were treated with 2 WP mixtures, grouping high (β-LG 1.25%, α-LA 1.25%, BSA 1.25%) and low (β-LG 0.07%, α-LA 0.15%, BSA 0.15%) selected concentrations of individual proteins that positively affected cell growth in a preceding dose-response study. Cells cultured in only basal Dulbecco's Modified Eagle Medium were included as a negative control, and cells cultured in 10% FBS as a positive control. Cells were maintained in the treatment media for 48 h (d 1 and 2) to support myoblast proliferation. Subsequently, all the treatments were replaced with a standard low mitogenic 2% horse serum (HS) medium until full differentiation (d 6). The treatment effects on morphology, viability, and lactate dehydrogenase release were assessed after d 1, 2, and 6, respectively. The results showed that WP stimulated cell proliferation under serum-free culture conditions, similar to the FBS control, and subsequently facilitated myotube formation when the WP or FBS treatments were switched to HS medium. After differentiation, these cells also exhibited increased expression of cell differentiation markers such as creatine kinase and citrate synthase and underwent morphological changes from spindle-shaped cells to fused elongated myotubes, in contrast to the negative control. This study demonstrates that WP are a promising and sustainable alternative for considerably replacing FBS-based growth supplements for use in cultivated animal products.

Microbiological and chemical hazards in cultured meat and methods for their detection

Cultured meat, which involves growing meat in a laboratory rather than breeding animals, offers potential benefits in terms of sustainability, health, and animal welfare compared to conventional meat production. However, the cultured meat production process involves several stages, each with potential hazards requiring careful monitoring and control. Microbial contamination risks exist in the initial cell collection from source animals and the surrounding environment. During cell proliferation, hazards may include chemical residues from media components such as antibiotics and growth factors, as well as microbial issues from improper bioreactor sterilization. In the differentiation stage where cells become muscle tissue, potential hazards include residues from scaffolding materials, microcarriers, and media components. Final maturation and harvesting stages risk environmental contamination from nonsterile conditions, equipment, or worker handling if proper aseptic conditions are not maintained. This review examines the key microbiological and chemical hazards that must be monitored and controlled during the manufacturing process for cultured meats. It describes some conventional and emerging novel techniques that could be applied for the detection of microbial and chemical hazards in cultured meat. The review also outlines the current evolving regulatory landscape around cultured meat and explains how thorough detection and characterization of microbiological and chemical hazards through advanced analytical techniques can provide crucial data to help develop robust, evidence-based food safety regulations specifically tailored for the cultured meat industry. Implementing new digital food safety methods is recommended for further research on the sensitive and effective detection of microbiological and chemical hazards in cultured meat.

Developmental, cytogenetic and epigenetic consequences of removing complex proteins and adding melatonin during in vitro maturation of bovine oocytes

Background

In vitro maturation (IVM) of germinal vesicle intact oocytes prior to in vitro fertilization (IVF) is practiced widely in animals. In human assisted reproduction it is generally reserved for fertility preservation or where ovarian stimulation is contraindicated. Standard practice incorporates complex proteins (CP), in the form of serum and/or albumin, into IVM media to mimic the ovarian follicle environment. However, the undefined nature of CP, together with batch variation and ethical concerns regarding their origin, necessitate the development of more defined formulations. A known component of follicular fluid, melatonin, has multifaceted roles including that of a metabolic regulator and antioxidant. In certain circumstances it can enhance oocyte maturation. At this stage in development, the germinal-vesicle intact oocyte is prone to aneuploidy and epigenetic dysregulation.

Objectives

To determine the developmental, cytogenetic and epigenetic consequences of removing CP and including melatonin during bovine IVM.

Materials and methods

The study comprised a 2 x 2 factorial arrangement comparing (i) the inclusion or exclusion of CP, and (ii) the addition (100 nM) or omission of melatonin, during IVM. Cumulus-oocyte complexes (COCs) were retrieved from stimulated cycles. Following IVM and IVF, putative zygotes were cultured to Day 8 in standard media. RNAseq was performed on isolated cumulus cells, cytogenetic analyses (SNP-based algorithms) on isolated trophectoderm cells, and DNA methylation analysis (reduced representation bisulfite sequencing) on isolated cells of the inner-cell mass.

Results

Removal of CP during IVM led to modest reductions in blastocyst development, whilst added melatonin was beneficial in the presence but detrimental in the absence of CP. The composition of IVM media did not affect the nature or incidence of chromosomal abnormalities but cumulus-cell transcript expression indicated altered metabolism (primarily lipid) in COCs. These effects preceded the establishment of distinct metabolic and epigenetic signatures several days later in expanded and hatching blastocysts.

Conclusions

These findings highlight the importance of lipid, particularly sterol, metabolism by the COC during IVM. They lay the foundation for future studies that seek to develop chemically defined systems of IVM for the generation of transferrable embryos that are both cytogenetically and epigenetically normal.

Autologous Platelet Lysate Is an Alternative to Fetal Bovine Serum for Canine Adipose-Derived Mesenchymal Stem Cell Culture and Differentiation

The use of fetal bovine serum (FBS) in regenerative medicine raises serious ethical and scientific concerns. We have cultured and differentiated the canine mesenchymal stem cells (cMSCs) in five different media combinations of autologous platelet lysate (A-PL) and FBS; consisting of 0% A-PL and 10% FBS (M-1), 2.5% A-PL and 7.5% FBS (M-2), 5% A-PL and 5% FBS (M-3), 7.5% A-PL and 2.5% FBS (M-4), and 10% A-PL and 0% FBS (M-5). The cMSCs were evaluated for their doubling time, differentiation efficiency, and expression of CD73, CD90, CD105, and PDGFRα. The mRNA expression of NT5E, THY1, ENG, PPARγ, FABP4, FAS, SP7, BGLAP, and SPP1 was also assessed. The results indicated non-significant differences in cellular proliferation/viability; positive expression of surface markers, and PDGFRα with substantial adipo/osteogenic differentiation. The expression of adipogenic (PPARγ, FABP4, FAS), and osteogenic (SP7, BGLAP, SPP1) genes were higher (p < 0.05) in the M5 group. In conclusion, A-PL in cMSCs culture did not negatively affect cellular proliferation and viability but also enhanced their genetic potential for multilineage differentiation. Our results indicate that A-PL can be used as an alternative for FBS to develop potent cMSCs under good manufacturing practice protocol for regenerative medicine.

Whole-Genome-Sequence-Based Evolutionary Analyses of HoBi-like Pestiviruses Reveal Insights into Their Origin and Evolutionary History

HoBi-like pestivirus (HoBiPeV), classified under Pestivirus H species, is an emerging cattle pathogen of high economic impact. However, the origin and evolution of HoBiPeV are not very clear due to a lack of full genomic sequences from diverse clades. This study aimed to determine full-genome sequences of HoBiPeV strains of three novel clades (c, d and e) and perform full-genome-based genetic and evolutionary analyses. Bayesian phylogenetic analyses herein confirmed the existence and independent evolution of four main HoBiPeV clades (a, c, d and e) globally, with genetic divergence ranging from 13.0% to 18.2%. Our Bayesian molecular clock estimates revealed that HoBiPeV most likely originated in India, with a dated tMRCA of 1938 (1762–2000), evidencing a more recent origin of HoBiPeV. The evolution rate of HoBiPeV was estimated to be 2.133 × 10−3 subs/site/year at full-genome level but varied widely among individual genes. Selection pressure analyses identified most of the positively selected sites in E2. Additionally, 21.8% of the ORF codon sites were found under strong episodic diversifying selection, providing first evidence of negative selection in HoBiPeV evolution. No recombination event was evident for HoBiPeV-c, d and e strains. These findings provide new insights into HoBiPeV origin and evolutionary history for better understanding the epidemiology and host–pathogen interactions and stimulate vaccine research.

Different impact of bovine complement regulatory protein 46 (CD46bov) as a cellular receptor for members of the species Pestivirus H and Pestivirus G

The genus Pestivirus within the family Flaviviridae comprises highly relevant animal pathogens such as bovine viral diarrhoea virus 1 and 2 (BVDV-1 and -2) classified into the two species Pestivirus A and Pestivirus B, respectively. First described in 2004, HoBi-like pestiviruses (HoBiPeV) represent emerging bovine pathogens that belong to a separate species (Pestivirus H), but share many similarities with BVDV-1 and -2. Additionally, two giraffe pestivirus (GPeV) strains both originating from Kenya represent another distinct species (Pestivirus G), whose members replicate very efficiently in bovine cells. In this study, we investigated the role of bovine complement regulatory protein 46 (CD46bov), the receptor of BVDV-1 and -2, in the entry of HoBiPeV and GPeV. For this purpose, bovine CD46-knockout and CD46-rescue cell lines were generated by CRISPR/Cas9 technology and subsequent trans-complementation, respectively. Our results provide strong evidence that the impact of CD46bov differs between viruses belonging to Pestivirus H and viruses representing Pestivirus G: CD46bov revealed to be a major cellular entry factor for HoBiPeV strain HaVi-20. In contrast, GPeV strain PG-2 presented as largely independent of CD46bov, suggesting a different entry mechanism involving other molecular determinants which remain to be identified. In addition, we demonstrated that, similar to BVDV-1 and -2, virus isolates of both Pestivirus H and Pestivirus G are able to adapt to cell culture conditions by using heparan sulfate to enter the host cell. In conclusion, our findings show that different bovine pestiviruses use diverse mechanisms of host cell entry.

The proteomic and particle composition of human platelet lysate for cell therapy products

Following health agencies warning, the use of animal origin supplements should be avoided in biological products proposed as therapy in humans. Platelet lysate and several other growth factors sources are alternatives to replace fetal calf serum, the current gold standard in clinical-grade cell culture. However, the platelet supplement's content lacks data due to different production methods. The principle behind these products relays on the lysis of platelets that release several proteins, some of which are contained in heterogeneous granules and coordinate biological functions. This study aims to analyze the composition and reproducibility of a platelet lysate produced with a standardized method, by describing several batches' protein and particle content using proteomics and dynamic light scattering. Proteomics data revealed a diversified protein content, with some related to essential cellular processes such as proliferation, morphogenesis, differentiation, biosynthesis, adhesion, and metabolism. It also detected proteins responsible for activation and binding of transforming growth factor beta, hepatocyte growth factor, and insulin-like growth factor. Total protein, biochemical, and growth factors quantitative data showed consistent and reproducible values across batches. Novel data on two major particle populations is presented, with high dispersion level at 231 ± 96 d.nm and at 30 ± 8 d.nm, possibly being an important way of protein trafficking through the cellular microenvironment. This experimental and descriptive analysis aims to support the content definition and quality criteria of a cell supplement for clinical applications.

First detection of emerging HoBi-like Pestivirus (BVD-3) among some persistently infected dairy cattle herds in Egypt

Bovine viral diarrhoea virus (BVDV) is a serious veterinary health concern worldwide. We conducted this study to determine the prevalence of persistent infections (PI) and identify the current strain among some dairy cattle herds in Egypt. A total of 240 serum samples were collected from six Egyptian provinces. Between 2019 and 2020, samples were tested by Enzyme linked immunosorbent assay (ELISA) for detection of PI animals, and then molecular characterization was performed. Six calves were found PI with a prevalence of 2.5% (6/240). Using molecular characterization, HoBi-like Pestivirus (BVD-3) was successfully identified in Egypt for the first time. Based on the BVD-3 reference strains on Genbank, the detected strains had an identity ranging from 98.8 to 99.6%. Partial nucleotide sequence of the 5'UTR gene for six tested samples was submitted to Genbank with accessions: OM324396, OM324397, OM324398, OM324399, OM3243100, and OM3243101.

Epidemiology of Pestivirus H in Brazil and Its Control Implications

Along with viruses in the Pestivirus A (Bovine Viral Diarrhea Virus 1, BVDV1) and B species (Bovine Viral Diarrhea Virus 2, BVDV2), members of the Pestivirus H are mainly cattle pathogens. Viruses belonging to the Pestivirus H group are known as HoBi-like pestiviruses (HoBiPev). Genetic and antigenic characterization suggest that HoBiPev are the most divergent pestiviruses identified in cattle to date. The phylogenetic analysis of HoBiPev results in at least five subgroups (a–e). Under natural or experimental conditions, calves infected with HoBiPev strains typically display mild upper respiratory signs, including nasal discharge and cough. Although BVDV1 and BVDV2 are widely distributed and reported in many South American countries, reports of HoBiPev in South America are mostly restricted to Brazil. Despite the endemicity and high prevalence of HoBiPev in Brazil, only HoBiPev-a was identified to date in Brazil. Unquestionably, HoBiPev strains in BVDV vaccine formulations are required to help curb HoBiPev spread in endemic regions. The current situation in Brazil, where at this point only HoBiPev-a seems present, provides a more significant opportunity to control these viruses with the use of a vaccine with a single HoBiPev subtype. Despite the lack of differentiation among bovine pestiviruses by current BVDV tests, the reduced genetic variability of HoBiPev in Brazil may allow reliable identification of cases within the region. On the other hand, introducing foreign ruminants, biologicals, and genetic material to South America, especially if it originated from other HoBiPev-endemic countries, should consider the risk of introducing divergent HoBiPev subtypes.

Molecular characterization of recent HoBi-like pestivirus isolates from cattle showing mucosal disease-like signs in India reveals emergence of a novel genetic lineage

Natural infections with HoBi-like pestivirus (HoBiPeV) have been detected in cattle in South America, Europe and Asia with a range of clinical manifestations including fatal mucosal disease (MD). In India, although HoBiPeV in cattle has been reported, there is no information on currently circulating HoBiPeV strains and associated severe clinical disease. Between September 2018 and December 2019, suspected cases of bovine viral diarrhoea with severe disease in cattle were noticed in farmers' small holdings in Tamil Nadu State. To determine the extent of pestivirus infection, blood, serum, nasal or oral swab samples of 46 cattle from 18 villages were tested. Based on the real-time RT-PCR, antigen ELISA and nucleotide sequencing results, pestivirus was detected in nine cattle from eight villages in two districts and all pestiviruses were identified as HoBiPeV. All nine HoBiPeV-infected cattle displayed clinical signs resembling MD and HoBiPeV isolates (n = 9) obtained were characterized at genetic and antigenic level. Phylogenetic analyses based on 5'-untranslated regions (5'-UTR), N^pro and combined 5'-UTR-N^pro gene sequences revealed that eight HoBiPeV isolates clustered into a clade, distinct from all reported HoBiPeV clades (a-d), whereas one belonged to HoBiPeV-d clade, thus providing evidence of emergence of a novel HoBiPeV clade (e). This was also supported by HoBiPeV-e clade-specific amino acid substitutions in N^pro and the antigenic reactivity patterns. The study demonstrates the existence and independent evolution of five HoBiPeV clades (four main clades) globally and surprisingly three exclusive to India. Also we confirm first HoBiPeV occurrence in southern India with predominant prevalence of HoBiPeV-e strains. Besides demonstrating increased HoBiPeV genetic diversity, here we show association of HoBiPeV with severe clinical disease involving fatalities highlighting impact of HoBiPeV on cattle health. The emergence of a novel HoBiPeV lineage provides new insights on global HoBiPeV epidemiology and genetic diversity reiterating the need for continuous monitoring of HoBiPeV in India.

HoBi-like pestivirus infection leads to bovine death and severe respiratory disease in China

HoBi-like pestivirus is an emerging atypical pestivirus in cattle and small ruminants, causing clinical signs similar to those observed in bovine viral diarrhoea virus infections. Natural infection of HoBi-like pestivirus has been reported in cattle herds and small ruminants in multiple countries in South America, Europe and Asia. However, HoBi-like pestiviruses were only identified from contaminated bovine serum and small ruminants in China. So far, no clinical cases induced by HoBi-like pestivirus infection were reported in Chinese cattle herds. Here, for the first time, we reported natural infection of HoBi-like pestivirus in a cattle herd in China. Sick cattle with severe respiratory and diarrhoea and high fatality rate were found in a beef cattle herd in Shandong province in November 2017. RT-PCR, viral isolation, sequencing and phylogenetic analysis showed that the primary causative agent was HoBi-like pestivirus. The isolated HoBi-like pestivirus strain, SDJN-China-2019, shared 94.1%-97.5% homology with the LV168-20_16RN strain from Brazil in nucleotide of 5'UTR, N^pro and E2 while it shared only 88.5%-92.1% homology with Asian HoBi-like virus strain Th/04-Khonkaen. Multiple unique mutations of amino acid were observed in N^pro and E2 proteins of SDJN-China-2019, which were different from that of other reference strains. In summary, this study provides the first evidence of HoBi-like pestivirus infection in Chinese cattle herds, raising potential threat to the cattle industry in China.

Analysis of irradiated Argentinean fetal bovine serum for adventitious agents

Fetal bovine serum (FBS) used in cell culture may be contaminated with adventitious agents, which can affect the production of biologicals and the results of clinical laboratory tests. We carried out a retrospective study to determine the incidence of adventitious agent contamination of Argentinean irradiated FBS dating from 2015 to 2019. We analyzed FBS batches for mycoplasma and adventitious viruses (bovine pestiviruses, bovine adenovirus, bluetongue virus, bovine parainfluenza virus 3, rabies virus, bovine parvovirus, bovine herpesvirus 1, bovine respiratory syncytial virus, and reovirus). Cell passages followed by direct immunofluorescence were carried out to check viability of the mentioned adventitious agents. Also, molecular detection of mycoplasma and pestiviruses was performed on the FBS samples. The presence of neutralizing antibodies against pestiviruses was determined. Molecular analyses indicated that frequencies of mycoplasma and pestiviruses in FBS were 14% and 84%, respectively. All of the batches were seronegative for pestiviral antibodies. After cell passages, all FBS samples were negative for hemadsorbent agents and by immunofluorescence for all of the viral species analyzed; PCR assays were negative for mycoplasma and pestiviruses. Our results demonstrate that, of all adventitious agents tested, local FBS batches only had traces of mycoplasma and pestiviruses; gamma irradiation was effective in inactivating them.

Removal of bovine viral diarrhea virus (BVDV) from lumpy skin disease virus (LSDV) vaccine stocks by passage on chorioallantoic membranes of fertilized hens' eggs

Bovine viral diarrhea virus (BVDV) is a common contaminant of Madin-Darby bovine kidney (MDBK) cells as well as fetal calf serum (FCS). It is pathogenic to cattle and regulatory authorities require that veterinary vaccine stocks are free from BVDV. MDBK cells are used in the generation of recombinant lumpy skin disease virus (LSDV) and have been used for the growth of LSDV vaccines. This paper describes how vaccine stocks can be cleared of BVDV by passage through an avian host, nonpermissive to BVDV, but permissive to LSDV. LSDV vaccine stocks were shown to be cleared of BVDV after passage on the chorioallantoic membranes (CAMs) of fertilized 7-day old hens' eggs. Vaccines were passaged a second time on CAMs before being grown in primary lamb testes (LT) cells. Vaccines retained BVDV-negative status after passage on LT cells.

Molecular Characterization of Pestiviruses in Fetal Bovine Sera Originating From Argentina: Evidence of Circulation of HoBi-Like Viruses

Serological evidence suggests that HoBi-like viruses, an emerging species within the Pestivirus genus of the Flaviviridae family, are in circulation in Argentina. While HoBi-like viruses were first isolated from Brazilian fetal bovine serum (FBS), no survey of Argentine FBS has been conducted. Therefore, 124 local samples of non-irradiated FBS originating from Argentina were surveyed for the presence of pestiviruses using RT-PCR. Amplicons from pestivirus positive samples were genotyped. Four samples were positive for HoBi virus-specific RT-PCR, while the BVDV-positive samples (n = 45) were classified as BVDV-1b (82.2%), BVDV-1a (13.3%), and BVDV-2 (4.5%). Virus isolation and serological profile assessment were performed for the four HoBi-positive FBS lots. These results confirm the circulation of HoBi-like virus in some regions of the Argentinean territory, highlighting the need to review the diagnostic techniques currently used in the clinical cases suspected of BVDV and in contamination control protocols for adventitious agents in cells and biotechnological products.

Pathogen spread and globalization: The case of Pestivirus heterogeneity in southern Italy

Pestiviruses are responsible for widespread diseases affecting cattle, pigs and other ruminants, presenting a wide range of clinical manifestations, with significant impact on animal production. Given the recent various reports of a relatively high number of new strains and atypical genomic variants, in the present study, ninety-seven genomic sequences from southern Italy have been evaluated applying the palindromic nucleotide substitutions method, based on 5'-UTR secondary structure alignment and computing genetic distance among strains in the internal ribosome entry site. Sequence analysis revealed a highly heterogeneous virus population, indicating the introduction of virus variants of Bovine viral diarrhea virus and Border disease virus species from foreign countries. The application of different analytical procedures was useful to avoid interpretation difficulties. Circulation of heterogeneous virus populations showed the need for more accurate epidemiological investigations and stringent veterinary controls to protect animal health and welfare.

Who's who in the Bovine viral diarrhea virus type 1 species: Genotypes L and R

The bovine viral diarrhea virus type 1 species is responsible for cosmopolitan diseases affecting cattle and other ruminants, with relevant impact on animal production. The species presents high genomic heterogeneity, with implications on control and prophylactic programs. Genomic traits of different genetic groups are often related to geographic origin. Atypical sequences have been reported from Pestivirus isolates originated from cattle in Turkey. Based on phylogenetic analysis of 5' untranslated region and Npro and secondary structure analysis of the 5'-UTR RNA, Turkish isolates have been segregated in two distinct genotypes. Out of the twenty-three identified BVDV-1 genotypes, the Turkish clusters, named L and R or 1.16 and 1.14, according to palindromic nucleotide substitution genotyping method, represent genomic clusters so far, not described elsewhere, suggesting geographic segregation. In order to avoid confusion in the current taxonomy of the species, nomenclature of described homonymous genotypes, referred to different genomic clusters, should be corrected.

Respiratory signs, fever and lymphopenia in calves inoculated with Brazilian HoBi-like pestiviruses

Hobi-like viruses (HobiPeV) comprise a novel, recently classified species of bovine pestiviruses, originally identified in commercial fetal bovine serum of Brazilian origin and, subsequently, isolated from diseased animals in several countries. Although frequently isolated from clinical cases, most HobiPeV isolates failed to reproduce overt disease in cattle upon experimental inoculation. Herein, we describe the outcome of experimental infection of four to six months-old seronegative calves with two Brazilian HobiPeV isolates. Calves inoculated intranasally with isolate SV478/07 developed viremia between days 2 and 9 post-inoculation (pi) and shed virus in nasal secretions up to day 11pi. These animals presented hyperthermia (day 7 to 10-11 pi) and lymphopenia from days 4 to 8pi. Clinically, all four calves developed varied degrees of apathy, anorexia, mild to moderate respiratory signs (nasal secretion, hyperemia), ocular discharge and pasty diarrhea in the days following virus inoculation. In contrast, calves inoculated with isolate SV757/15 presented only hyperthermia (days 3 to 10-11 pi) and lymphopenia (days 4-8 pi), without other apparent clinical signs. In these animals, viremia was detected up to day 9 pi and virus shedding in nasal secretions lasted up to day 12-14 pi. Both groups seroconverted to the inoculated viruses, developing virus neutralizing (VN) titers from 320 to 5120 at day 28pi. These results extend previous findings that experimental infections of calves with HobiPeV are predominantly mild, yet they also indicate that field isolates may differ in their ability to cause disease in susceptible animals.

Human Cells Grown With or Without Substitutes for Fetal Bovine Serum

Safety concerns over cell-derived pharmaceutical products being manufactured in supplements of fetal bovine serum (FBS) have ignited pleas to replace FBS. Herein, four newly marketed alternatives to FBS were compared: a xeno-free product called Cell-Ess®, a human platelet lysate marketed as GroPro®, and two mixtures of adult bovine serum varying in their proportions of neonatal growth factors, called Liporo® and FetalGro®. An endothelial cell line (C2BBe1) and a neuronal cell line (SHSY5Y) near confluency in media with 10% FBS were selectively scraped and taken through a 25-day step-wise algorithm to replace FBS, and another human endothelial cell line (HRA-19) was studied to replicate C2BBe1. Cells were stained, counted, and compared for viability, migration, and spheroids. The C2BBe1 and HRA-19 cell lines failed to proliferate in 10% Cell-Ess® but grew in 10% GroPro® or 10% FetalGro® reasonably well compared to reference 10% FBS. With SH-SY5Y, only FetalGro® approached FBS's efficacy. These were all inferior to 11 different branded lots of FBS (positive controls), but five days into switching just amongst the FBS brands, 4 of 11 supported less proliferation than reference FBS in endothelial HRA-19 (p < 0.004). Moreover, neurospheres were enriched in two branded lots of FBS and FetalGro® (each p < 0.004), neurospheres being an unwanted phenotype for any neuronal cell application. Because platelet-derived GroPro® stood out amongst the non-FBS growth supplements to allow proliferation without inducing spheroids, it seems the best (mindful that the cells still grew slower in it compared to FBS). While no perfect replacement was found amongst the alternatives to FBS, the algorithm for switching should be useful in future testing of new alternatives to FBS as the need arises to switch from FBS and expand pharmaceutical products with safety for human use.

Bovine viral diarrhea virus type 1 current taxonomy according to palindromic nucleotide substitutions method

Pestivirus bovine viral diarrhea virus type 1 species is responsible for cosmopolitan diseases affecting cattle and other ruminants, presenting a wide range of clinical manifestations, with relevant impact on zootechnic production. Understanding genomic characteristic and virus taxonomy is fundamental in order to sustain control and prophylactic programs. Given the recent various studies reporting a relatively high number of new strains, in particular from Asian countries, in the present study, four hundred-eighty-two genomic sequences have been evaluated applying the palindromic nucleotide substitutions method for genotyping. Based on the secondary structure alignment and computing genetic distance among strains in the 5' untranslated region of Pestivirus RNA, the current taxonomy of the species was reviewed. Twenty-two genotypes have been identified, applying a nomenclature based on divergence in the genus.

A Novel Genetic Group of Bovine Hepacivirus in Archival Serum Samples from Brazilian Cattle

Hepatitis C virus (HCV) (genus Hepacivirus; family Flaviviridae) is a major human pathogen causing persistent infection and hepatic injury. Recently, emerging HCV-like viruses were described infecting wild animals, such as bats and rodents, and domestic animals, including dogs, horses, and cattle. Using degenerate primers for detecting bovine pestiviruses in a 1996 survey three bovine serum samples showed a low identity with the genus Pestivirus of the Flaviviridae family. A virus could not be isolated in cell culture. The description of bovine hepaciviruses (BovHepV) in 2015 allowed us to retrospectively identify the sequences as BovHepV, with a 88.9% nucleotide identity. In a reconstructed phylogenetic tree, the Brazilian BovHepV samples grouped within the bovine HCV-like cluster in a separated terminal node that was more closely related to the putative bovine Hepacivirus common ancestor than to bovine hepaciviruses detected in Europe and Africa.

Re-using blood products as an alternative supplement in the optimisation of clinical-grade adipose-derived mesenchymal stem cell culture

Objectives

Adipose-derived mesenchymal stem cells (ADMSCs) are a promising strategy for orthopaedic applications, particularly in bone repair. Ex vivo expansion of ADMSCs is required to obtain sufficient cell numbers. Xenogenic supplements should be avoided in order to minimise the risk of infections and immunological reactions. Human platelet lysate and human plasma may be an excellent material source for ADMSC expansion. In the present study, use of blood products after their recommended transfusion date to prepare human platelet lysate (HPL) and human plasma (Hplasma) was evaluated for in vitro culture expansion and osteogenesis of ADMSCs.

Methods

Human ADMSCs were cultured in medium supplemented with HPL, Hplasma and a combination of HPL and Hplasma (HPL+Hplasma). Characteristics of these ADMSCs, including osteogenesis, were evaluated in comparison with those cultured in fetal bovine serum (FBS).

Results

HPL and HPL+Hplasma had a significantly greater growth-promoting effect than FBS, while Hplasma exhibited a similar growth-promoting effect to that of FBS. ADMSCs cultured in HPL and/or Hplasma generated more colony-forming unit fibroblasts (CFU-F) than those cultured in FBS. After long-term culture, ADMSCs cultured in HPL and/or Hplasma showed reduced cellular senescence, retained typical cell phenotypes, and retained differentiation capacities into osteogenic and adipogenic lineages.

Conclusion

HPL and Hplasma prepared from blood products after their recommended transfusion date can be used as an alternative and effective source for large-scale ex vivo expansion of ADMSCs.

Cite this article: J. Phetfong, T. Tawonsawatruk, K. Seenprachawong, A. Srisarin, C. Isarankura-Na-Ayudhya, A. Supokawej. Re-using blood products as an alternative supplement in the optimisation of clinical-grade adipose-derived mesenchymal stem cell culture. Bone Joint Res 2017;6:414–422. DOI: 10.1302/2046-3758.67.BJR-2016-0342.R1.

Effects of oocytes exposure to bovine diarrhea viruses BVDV-1, BVDV-2 and Hobi-like virus on in vitro-produced bovine embryo development and viral infection

As production of in vitro (IVP) bovine embryos steadily increases, the sanitary risk associated with IVP embryos remains a concern. One of the greatest concerns is how BVDV may be transmitted through IVP embryos. The objective of this study was to evaluate the effects caused by BVDV-1, BVDV-2 and Hobi-like virus exposure during in vitro maturation on embryo development and viral infection. Abittior-derived oocytes were randomly assigned for in vitro maturation with serial concentrations of BVDV-1 (3.12 × 10² - 2.50 × 10³ TCID₅₀/100 μL), BVDV-2 (6.25 × 10¹ - 5.20 × 10² TCID₅₀/100 μL) or Hobi-like virus (1.90 × 10² - 1.58 × 10³ TCID₅₀/100 μL) for 22-24 h. After maturation, oocytes were fertilized and embryo cultured following standard in vitro procedures. Embryo development was evaluated and percentage of respective, positive BVDV degenerated and viable embryos were evaluated by RT-qPCR. No concentration of BVDV-1 altered embryo development as measured by cleavage and blastocyst rates, compared to negative control group. However 100% of degenerated embryos and 50-100% of viable embryos tested positive for BVDV-1, depending on the viral concentration. BVDV-2 exposed oocytes had higher cleavage rates than the negative control group (60.2-64.1% vs 49.8%; P = 0.003-0.032). However, no difference was detected for blastocyst rates. In aadition, 100% of degenerated embryos and 20-50% of viable embryos tested positive for BVDV-2. Hobi-like virus treated oocytes had reduced cleavage rates for the three highest viral concentrations (33.3-38.0% vs 49.8% for negative controls; P ≤ 0.001-0.014). Blastocyst rates were only reduced in the 7.9 × 10² Hobi-like virus concentration (6.9 ± 0.9% vs 15.1 ± 1.6%; P = 0.009), when calculated by oocyte number. 50-80% of degenerated embryos tested positive for Hobi-like virus. No viable embryos from the Hobi-like virus treated oocytes tested positive. These results suggest that IVP embryos from BVDV-1 and -2 infected oocytes develop normally, but carry the virus. However, Hobi-like virus infected oocytes had reduced cleavage and cause pre-implantation embryo loss, but viable embryos did not carry the virus.

Antigenic diversity of Brazilian isolates of HoBi-like pestiviruses

Hobi-like viruses comprise an unclassified group of bovine pestiviruses related to bovine viral diarrhea virus 1 (BVDV-1) and 2 (BVDV-2). These viruses were originally identified in fetal bovine serum from Brazilian origin and, subsequently, isolated from diseased animals in several countries. Herein we performed an antigenic characterization of eight Brazilian HoBi-like viruses isolated from persistently infected (PI) animals and from gastroenteric disease (2007-2015). Phylogenetic analysis based on the 5' unstranslated region (UTR) clustered these viruses with other HoBi-like viruses from European and Asiatic origin. Monoclonal antibody (MAb) binding indicated variability in the Hobi-like virus glycoprotein E2 and significant differences from the homologous BVDV-1 and BVDV-2 glycoprotein. Analysis of antigenic relatedness based on virus-neutralizing titers using virus-specific antisera revealed that HoBi-like viruses are antigenically very different from BVDV-1 and, to a lesser extent, from BVDV-2. Cross-neutralizing assays between pairs of HoBi-like viruses and their respective antisera indicated the existence of antigenic variability among these viruses, even for viruses isolated from the same herd in different occasions. Moreover, the identification of a HoBi-like isolate with low antigenic similarity with the other isolates indicates the potential existence of antigenic subgroups among HoBi-like virus isolates. Finally, sera of lambs immunized with commercial BVDV vaccines showed low or undetectable neutralizing activity against HoBi-like isolates. These results indicate significant antigenic differences between BVDV genotypes and Brazilian HoBi-like viruses and the existence of antigenic variability within this atypical group of pestiviruses. These findings extend the knowledge about the antigenic diversity of HoBi-like viruses and reinforce the need for their inclusion in current BVDV vaccines.

New Leaves in the Growing Tree of Pestiviruses

Pestiviruses are a group of viruses of veterinary importance infecting livestock animals like pigs, cattle, and sheep, and also wildlife animals like wild boar and different deer species. While for decades only four classical species (Classical swine fever virus, Bovine viral diarrhea virus types 1 and 2, Border disease virus), and a few so-called atypical pestiviruses were known (e.g., Giraffe virus, Pronghorn virus, HoBi virus), a series of novel pestiviruses was identified in the last years (Bungowannah virus, Bat pestivirus, Norway rat pestivirus, Atypical porcine pestivirus, LINDA virus). The Australian Bungowannah virus could be isolated and further characterized by classical sequencing, but all the other latest novel pestiviruses were identified by metagenomics using next-generation sequencing technologies. Here, we describe these new viruses and their discovery and characterization. Differentiation is made between the occurrence of classical pestiviruses in new species and novel viruses or virus types.

Genetic typing of bovine viral diarrhoea virus in cattle on Irish farms

The aim was to carry out a phylogenetic study of bovine viral diarrhoea viruses (BVDV) circulating in Irish cattle herds from 2011 to 2014. Three hundred and twenty five viruses from 267 herds were subtyped by nucleotide sequence analysis of the 5'UTR and/or the N^pro regions. All viruses investigated in this study belonged to species BVDV-1 with BVDV-1a as the prominent subtype (97%). Subtypes BVDV-1b, BVDV-1d and BVDV-1e were also identified for the first time in Ireland. Pairwise alignments of 225 viruses with complete sequences for the 5'UTR and the N^pro regions were performed to determine a low conflict threshold for virus strain demarcation. One hundred and seventy seven unique virus strains were identified. The study revealed significant levels of herd specific clustering of strains but no geographical or temporal clustering. Similar virus strains were identified in different counties, provinces and years indicating the potential to investigate the epidemiology of the disease by combining sequence analysis with animal movement data.

Genome analysis of an atypical bovine pestivirus from fetal bovine serum

We report the complete genome sequence of a bovine pestivirus LVRI/cont-1 originated from a commercial batch of fetal bovine serum. Its complete genome consists of 12,282 nucleotides (nt), which contain an open reading frame (ORF) of 11,700 bp flanked by 5' and 3' untranslated regions (383 and 199 bp). The size of the 5'UTR and the individual protein coding region of LVRI/cont-1 are identical to those of the reference virus Th/04_KhonKaen, but it has a deletion of the first 56 nt in the 3'UTR. Alignment of the complete nucleotide sequence and phylogenetic analysis indicate that this viral isolate belongs to atypical pestiviruses.

Complete Genome Sequence of Bovine Viral Diarrhea Virus-1 Strain Egy/Ismailia/2014, Subtype 1b

Here, we report the complete genome sequence of bovine viral diarrhea virus-1b (BVDV-1b), strain Egy/Ismailia/2014. The virus genome is composed of 12,217 nucleotides organized as one open reading frame encoding 3,898 amino acids. This report will assist efforts in diagnostics, studying molecular epidemiology, and control of BVDV in Egypt.

HoBi-like viruses – the typical ‘atypical bovine pestivirus’

HoBi-like viruses, also referred to as bovine viral diarrhea virus 3 (BVDV-3) and atypical pestivirus, have been proposed as a new putative bovine pestivirus species. These viruses were first identified in the last decade and are currently distributed in at least three continents. Published findings suggest that these viruses may be endemic at least in parts of South America and Asia. The clinical presentations in cattle, described in field outbreaks and controlled studies, are similar to those associated with BVDV and range from subclinical to mild clinical signs, sporadically associated with reproductive losses, respiratory illness and hemorrhagic syndrome. The complete host range of HoBi-like virus is unknown, but data suggest higher adaptation of HoBi-like viruses to ruminants than swine. Acute infections, characterized by mild clinical signs, such as low-grade pyrexia and leukopenia, have been observed in both cattle and sheep. Virus has been isolated from nasal swabs indicating that virus was being shed. While seroconversion has been observed in pigs, no clinical presentation or viral shedding was evident following inoculation. While some commercial BVDV diagnostic tests may detect HoBi-like viruses, these tests do not differentiate between BVDV and HoBi-like viruses. The differentiation of BVDV and HoBi-like viruses is critical to the design of surveillance programs for these viruses.

Genetic diversity of bovine viral diarrhea viruses in commercial bovine serum batches of Chinese origin

Bovine viral diarrhea virus (BVDV) is often detected in commercial bovine serum. BVDV genetic diversity was investigated in commercial bovine serum of Chinese origin. Twenty-two batches of bovine serum were obtained from 10 suppliers with different geographic origins in China, and 20 batches of bovine serum were positive by reverse-transcription polymerase chain reaction (RT-PCR) and sequencing. Phylogenetic reconstructions of partial 5'UTR sequences indicated that the samples examined in this work clustered within the BVDV type 1 and BVDV type 2 genotypes. Interestingly, 3 sample sequences clustered into CSFV. These results suggest a high genetic diversity in Chinese BVDV field isolates. This study will benefit epidemiological surveys of BVDV detected in China.

Extended genetic diversity of bovine viral diarrhea virus and frequency of genotypes and subtypes in cattle in Italy between 1995 and 2013

Genetic typing of bovine viral diarrhea virus (BVDV) has distinguished BVDV-1 and BVDV-2 species and an emerging putative third species (HoBi-like virus), recently detected in southern Italy, signaling the occurrence of natural infection in Europe. Recognizing the need to update the data on BVDV genetic variability in Italy for mounting local and European alerts, a wide collection of 5′ UTR sequences (n = 371) was selected to identify the frequency of genotypes and subtypes at the herd level. BVDV-1 had the highest frequency, followed by sporadic BVDV-2. No novel HoBi-like viruses were identified. Four distribution patterns of BVDV-1 subtypes were observed: highly prevalent subtypes with a wide temporal-spatial distribution (1b and 1e), low prevalent subtypes with a widespread geographic distribution (1a, 1d, 1g, 1h, and 1k) or a restricted geographic distribution (1f), and sporadic subtypes detected only in single herds (1c, 1j, and 1l). BVDV-1c, k, and l are reported for the first time in Italy. A unique genetic variant was detected in the majority of herds, but cocirculation of genetic variants was also observed. Northern Italy ranked first for BVDV introduction, prevalence, and dispersion. Nevertheless, the presence of sporadic variants in other restricted areas suggests the risk of different routes of BVDV introduction.

Mucosal disease-like syndrome in a calf persistently infected by Hobi-like pestivirus

A calf persistently infected with Hobi-like pestivirus displayed severe clinical signs and subsequently died. Gross lesions and histopathological changes were suggestive of hemorrhagic and necrotic inflammation involving several tissues. A Hobi-like pestivirus pair was isolated from the dead calf, i.e., cytopathogenic (CP) and noncytopathogenic (NCP) strains strictly related to each other and to Italian prototype isolates at the genetic level. Two biotype-specific real-time reverse transcription-PCR assays determined the time of the emergence of the CP virus as 1 month before the calf's death. This highest RNA titers were reached in lymphoid and nervous system tissues, whereas only traces of CP viral RNA were found in blood. In contrast, great NCP virus loads were present in all tissues and biological fluids. The present report provides new insights into the pathogenesis and molecular mechanisms of this emerging group of pestiviruses.

Unbiased analysis by high throughput sequencing of the viral diversity in fetal bovine serum and trypsin used in cell culture

Fetal bovine serum (FBS) and trypsin are reagents used in cell culture and have been the source of viral contamination of pharmaceutical products. We performed high throughput sequencing (HTS) of two pools of commercial batches of FBS and three commercial batches of trypsin. Taxonomies were assigned by comparing sequences of contigs and singletons to the entire NCBI nucleic acid and protein databases. The same major viral species were evidenced between batches of a given reagent but the proportion of viral reads among total reads varied markedly between samples (from 0.002% to 22.7%). In FBS, the sequences found were mainly from bovine viral diarrhea virus (BVDV) 1 to 3 and bovine parvovirus 3 (BPV3). The BVDV sequences derived from FBS showed only minor discrepancies with primers generally used for the screening of BVDV. Viral sequences in trypsin were mainly from porcine circovirus type 2. Other known viral sequences at lower read counts and potential new viral species (bovine parvovirus and bovine pegivirus) were evidenced. The load of some known and new viruses detected by HTS could be quantified by qPCR. Results of HTS provide a framework for evaluating the pertinence of control measures including the design of PCRs, bioassays and inactivation procedures.

Lack of evidence for the presence of emerging HoBi-like viruses in North American fetal bovine serum lots

The detection of an emerging pestivirus species, "HoBi-like virus," in fetal bovine serum (FBS) labeled as U.S. origin, but packaged in Europe, raised concerns that HoBi-like virus may have entered the United States. In the current study, 90 lots of FBS originating in North America (NA) were screened for pestivirus antigen and antibodies. Lots in group 1 (G1, 72 samples) and group 2 (G2, 9 samples) originated in NA and were packaged in the United States. Group 3 (G3) was composed of 9 lots collected in NA and processed in Europe. Lots in G1 were claimed negative for Bovine viral diarrhea virus (BVDV), while lots in G2 and G3 were claimed positive by the commercial processor. All lots in G1 and G2 tested negative by reverse transcription polymerase chain reaction (RT-PCR) using HoBi-like-specific primers. Two G1 lots tested positive by BVDV RT-PCR. One of these was also positive by virus isolation. All G2 lots were positive by BVDV RT-PCR. In addition, four G2 lots were VI positive while 1 lot was antigen-capture enzyme-linked immunosorbent assay (ELISA) positive. Two G3 lots were positive by HoBi-like-specific RT-PCR tests. All lots were negative for HoBi_D32/00 neutralizing antibodies. Seven lots (4 G1; 1 G2; 2 G3) had antibodies against BVDV by virus neutralization and/or antigen-capture ELISA. While there is no evidence of HoBi-like viruses in NA based on tested samples, further studies are required to validate HoBi-like virus-free status and develop means to prevent the spread of HoBi-like virus into NA.

HoBi-like viruses: an emerging group of pestiviruses

The genus Pestivirus is composed of 4 important pathogens of livestock: Bovine viral diarrhea virus 1 and 2 (BVDV-1 and BVDV-2), Classical swine fever virus (CSFV), and Border disease virus of sheep (BDV). BVDV are major pathogens of cattle, and infection results in significant economic loss worldwide. A new putative pestivirus species, tentatively called "HoBi-like," "BVDV-3," or "atypical pestiviruses," was first identified in Europe in fetal bovine serum (FBS) imported from Brazil. HoBi-like viruses are related to BVDV at the genetic and antigenic levels. Further, the disease caused by these new viruses resembles clinical presentations historically associated with BVDV infection, including growth retardation, reduced milk production, respiratory disease, reduced reproductive performance, and increased mortality among young stock. Current BVDV diagnostic tests may fail to detect HoBi-like viruses or to differentiate between BVDV and HoBi-like viruses. Further, commercial tests for BVDV exposure, based on serological response, do not reliably detect HoBi-like virus exposure, and cross protection against HoBi-like viruses conferred by current BVDV vaccines is likely limited. As many HoBi-like viruses, characterized to date, were isolated from FBS originating from Brazil, it is assumed that the agent is probably widespread in Brazilian herds. Nevertheless, reports of natural infection in Southeast Asia and Europe demonstrate that these viruses are not restricted to South America. Increased demand for FBS has led to widespread distribution of FBS originating in HoBi-like virus endemic regions. The contamination of such FBS with HoBi-like viruses may lead to spread of this virus to other regions.

Virome analysis for identification of novel mammalian viruses in bat species from Chinese provinces

Bats are natural hosts for a large variety of zoonotic viruses. This study aimed to describe the range of bat viromes, including viruses from mammals, insects, fungi, plants, and phages, in 11 insectivorous bat species (216 bats in total) common in six provinces of China. To analyze viromes, we used sequence-independent PCR amplification and next-generation sequencing technology (Solexa Genome Analyzer II; Illumina). The viromes were identified by sequence similarity comparisons to known viruses. The mammalian viruses included those of the Adenoviridae, Herpesviridae, Papillomaviridae, Retroviridae, Circoviridae, Rhabdoviridae, Astroviridae, Flaviridae, Coronaviridae, Picornaviridae, and Parvovirinae; insect viruses included those of the Baculoviridae, Iflaviridae, Dicistroviridae, Tetraviridae, and Densovirinae; fungal viruses included those of the Chrysoviridae, Hypoviridae, Partitiviridae, and Totiviridae; and phages included those of the Caudovirales, Inoviridae, and Microviridae and unclassified phages. In addition to the viruses and phages associated with the insects, plants, and bacterial flora related to the diet and habitation of bats, we identified the complete or partial genome sequences of 13 novel mammalian viruses. These included herpesviruses, papillomaviruses, a circovirus, a bocavirus, picornaviruses, a pestivirus, and a foamy virus. Pairwise alignments and phylogenetic analyses indicated that these novel viruses showed little genetic similarity with previously reported viruses. This study also revealed a high prevalence and diversity of bat astroviruses and coronaviruses in some provinces. These findings have expanded our understanding of the viromes of bats in China and hinted at the presence of a large variety of unknown mammalian viruses in many common bat species of mainland China.

Hobi-like pestivirus: both biotypes isolated from a diseased animal

A Hobi-like pestivirus pair consisting of cytopathogenic (cp) and non-cytopathogenic (noncp) strains, Italy 83/10cp and Italy 83/10ncp, was isolated from the lung of a heifer that died of respiratory disease. The noncp and cp viruses were isolated on Madin-Darby bovine kidney cells and separated by plaque purification and end point dilution. Analysis of the nearly full-length genomes revealed that the two viruses were very closely related to each other and to the noncp Hobi-like strain Italy 1/10-1, which had been isolated a few weeks earlier from the same herd. One major difference between noncp and cp viruses concerned the presence of a cellular Jiv sequence in the 3' domain of the NS2-encoding region of the cp strain. This is the first study, to our knowledge, reporting the isolation and molecular characterization of a Hobi-like virus pair.

Evaluation of envelope glycoprotein E(rns) of an atypical bovine pestivirus as antigen in a microsphere immunoassay for the detection of antibodies against bovine viral diarrhea virus 1 and atypical bovine pestivirus

Atypical bovine pestiviruses are related antigenically and phylogenetically to bovine viral diarrhea viruses (BVDV-1 and BVDV-2), and may cause the same clinical manifestations in animals. Glycoprotein E(rns) of an atypical bovine pestivirus Th/04_KhonKaen was produced in a baculovirus expression system and was purified by affinity chromatography. The recombinant E(rns) protein was used as an antigen in a microsphere immunoassay for the detection of antibodies against BVDV-1 and atypical bovine pestivirus. The diagnostic performance of the new method was evaluated by testing a total of 596 serum samples, and the assay was compared with enzyme-linked immunosorbent assay (ELISA). Based on the negative/positive cut-off median fluorescence intensity (MFI) value of 2800, the microsphere immunoassay had a sensitivity of 100% and specificity of 100% compared to ELISA. The immunoassay was able to detect antibodies against both BVDV-1 and the atypical pestivirus. This novel microsphere immunoassay has the potential to be multiplexed for simultaneous detection of antibodies against different bovine pathogens in a high-throughput and economical way.