Fetal Bovine Serum Samples Research Articles

Au-Fe3O4 heterodimer multifunctional nanoparticles-based platform for ultrasensitive naked-eye detection of Salmonella typhimurium

In this work, we developed an ultrasensitive colorimetry for Salmonella typhimurium detection with multifunctional Au-Fe3O4 dumbbell-like nanoparticles (DBNPs) which possessed easy bio-modifiability, excellent LSPR characteristics, superparamagnetic properties and super peroxidase-like activity. In the detection, the anti-S. typhimurium antibody modified DBNPs (IDBNPs) bound with S. typhimurium and aggregated on their surfaces in a large number, which showed much quicker magnetic response than free IDBNPs. By controlling appropriate separation conditions, IDBNPs@S. typhimurium composites were captured, while free IDBNPs were remained in the supernatant. Therefore, by detecting the absorbance of the supernatant, quantitative detection was achieved from 10 to 1000 CFU/mL. Moreover, utilizing the peroxidase-like activity of IDBNPs, we further realized semi-quantitative naked-eye detection. By adding ABTS into the above supernatant, which was oxidized to green chelate (OxABTS), colorimetric signal was amplified significantly, and meanwhile, the green chelates and the wine-red IDBNPs engendered mixed color, enhancing the range of color gradation and greatly improving the visual resolution. Finally, a detection limit (10 CFU/mL) comparable with that of above spectrum measurement was achieved. Besides, our method exhibited efficient capture capability (nearly 100% even for rare S. typhimurium), and had good stability and specificity, and acceptable anti-interference ability in fetal bovine serum and milk samples.

SERS determination of dopamine using metal-organic frameworks decorated with Ag/Au noble metal nanoparticle composite after azo derivatization with p-aminothiophenol.

A specific surface-enhanced Raman scattering (SERS) assay for dopamine (DA) based on an azo derivatization reaction is proposedfor the first time by preparation of p-aminothiophenol (PATP)-modified composite SERS substrate, composed of metal-organic framework (MIL-101) decorated with Au and Ag nanoparticles. As the result, the SERS method for detection of theazo reaction between PATP and DA exhibits superior sensitivity, selectivity, and stability. A reasonable linearity in the range 10-6 to 10-10mol∙L-1 is achieved, and the limit of detection is 1.2 × 10-12mol∙L-1. Thereactive SERS assay is free from interference in complex physiological fluid. The feasibility of the proposed SERS method for the detection of DA levels in fetal bovine serum (FBS) samples and human serum samples is validated by HPLC-MS methods, displaying promising application potential in early disease diagnosis.

Using an insulating fiber as the sampling probe and ionization substrate for ambient ionization-mass spectrometric analysis of volatile, semi-volatile, and polar analytes.

A sharp metal needle used as the ionization emitter in conventional atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) is usually required for analyte ionization through corona discharge (i.e., gas discharge). Nevertheless, we herein demonstrate that an insulating fiber (tip diameter: 10-60µm; length: ~ 1cm) made of glass or bamboo can function as an APCI-like ionization emitter. Although no direct electric contact is made on the fiber, the ionization of volatiles and semi-volatiles occurs when the fiber is placed close (~ 1mm) to the inlet of the mass spectrometer. No analyte ion signals can be observed without placing the insulating fiber in front of the mass spectrometer. The generation of ion species mainly relies on the electric field provided by the mass spectrometer. Presumably, owing to the high electric field provided by the mass spectrometer, the dielectric breakdown voltages of gas molecules in the air and the fiber are overcome, leading to the ionization of analytes in gas phase. In addition, the insulating fiber can function as a holder for sample solutions. Electrospray ionization-like processes derived from polar analytes such as amino acids, peptides, and proteins can readily occur when the insulating fiber deposited with a sample droplet is placed close to the inlet of the mass spectrometer. The feasibility of using the current approach for the detection of nonpolar and polar analytes from complex fetal bovine serum samples without tedious sample pretreatment is demonstrated in this work. The main advantage of using the suggested fiber is that the fiber can be used as the sampling probe to pick up samples and placed in front of a mass spectrometer for direct MS analysis. The application of using a robust, insulating, and disposable probe to pick up samples from real samples such as onion, honey, and pork samples followed by direct MS analysis is also demonstrated.

A novel ratiometric fluorescent probe for detection of l-glutamic acid based on dual-emission carbon dots

In this article, we report for the first time the use of a dual-emission carbon dots (CDs) with orange-yellow fluorescence for the detection of l-glutamic acid (L-Glu). The CDs was synthesized through a facile strategy of one-pot hydrothermal route using o-phenylenediamine (oPD) and oxalic acid. The CDs exhibit two fluorescence emission peaks around 453 nm and 560 nm when the excitation wavelength is at 390 nm. In the existence of L-Glu the fluorescence at 560 nm was decreased, whereas the fluorescence at 453 nm was constant. The fluorescence intensity ratio at 560 nm and 453 nm (F560/F453) expressed two great linear relationships in the L-Glu concentration range from 0 to 200 μM and 200–400 μM, respectively, with a detection limit (LOD) of about 0.085 μM. In addition, it was used to analyze L-Glu in fetal bovine serum samples successfully, which recoveries were ranging from 97.07 to 103.7%. Those results demonstrate CDs can be further explored in biomedicine studies.

Facile Synthesis of Water-Soluble Rhodamine-Based Polymeric Chemosensors via Schiff Base Reaction for Fe3+ Detection and Living Cell Imaging.

Quantitative and accurate determination of iron ions play a vital role in maintaining environment and human health, but very few polymeric chemosensors were available for the detection of Fe3+ in aqueous solutions. Herein, a water-soluble rhodamine-poly (ethylene glycol) conjugate (DRF-PEG), as a dual responsive colorimetric and fluorescent polymeric sensor for Fe3+ detection with high biocompatibility, was first synthesized through Schiff base reaction between rhodamine 6G hydrazide and benzaldehyde-functionalized polyethylene glycol. As expected, the introduction of PEG segment in DRF-PEG significantly improved the water solubility of rhodamine derivatives and resulted in a good biosensing performance. The detection limit of DRF-PEG for Fe3+ in pure water is 1.00 μM as a fluorescent sensor and 3.16 μM as a colorimetric sensor at pH 6.5. The specific sensing mechanism of DRF-PEG toward Fe3+ is proposed based on the intramolecular charge transfer (ICT) mechanism, in which the O and N atoms in rhodamine moiety, together with the benzene groups from benzaldehyde-modified PEG segment, participate in coordination with Fe3+. Furthermore, DRF-PEG was applied for the ratiometric imaging of Fe3+ in HeLa cells and showed the potential for quantitative determination of Fe3+ in fetal bovine serum samples. This work provides insights for the design of water-soluble chemosensors, which can be implemented in iron-related biological sensing and clinical diagnosis.

Colorimetric assay for the detection of dopamine using bismuth ferrite oxide (Bi2Fe4O9) nanoparticles as an efficient peroxidase-mimic nanozyme

This work describes the preparation of ternary bismuth ferrite oxide nanoparticles (Bi2Fe4O9 NPs) with an enzyme mimetic activity for dopamine (DA) qualitative and quantitative detection. Bi2Fe4O9 NPs were prepared using a facile, low cost, and one-pot hydrothermal treatment. The chemical composition, morphology, and optical properties of Bi2Fe4O9 nanozyme were characterized using different techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction pattern (XRD), X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), dynamic light scattering (DLS), field-emission scanning electron microscopy (FESEM) imaging, FESEM-energy dispersive X-ray spectroscopy (EDS), UV–vis absorption, and fluorescence emission spectroscopy. Bi2Fe4O9 NPs were utilized to catalyze the oxidation of a typical chromogenic peroxidase substrate, 3,3′,5,5′-tetramethylbenzidine (TMB), to form the blue-colored oxidized product (oxTMB), in the presence of hydrogen peroxide (H2O2). All reactions occurred in acetate buffer solution (pH 3.5) to generate hydroxyl radicals (•OH) and the kinetics were followed by UV–vis absorbance at 654 nm. The steady-state kinetic parameters were obtained from the Michaelis-Menten equation and exhibited a good catalytic efficiency of Bi2Fe4O9 NPs as enzyme mimetics. Michaelis–Menten constant (Km) values were estimated as 0.07 and 0.73 mM for TMB and H2O2, respectively. The presented method is efficient, rapid, cost-effective, and sensitive for the colorimetric detection of dopamine with a linear range (LR) from 0.15 to 50 μM and a detection limit (LOD) of 51 nM. The proposed colorimetric sensor was successfully applied for the detection of different concentrations of dopamine in spiked fetal bovine serum (FBS) and horse serum (HS) samples. It is anticipated that Bi2Fe4O9 nanozyme holds great potential in biomedical analysis and diagnostic applications of dopamine-related diseases.

Metagenomic analysis reveals presence of different animal viruses in commercial fetal bovine serum and trypsin.

Animal-derived biological products, such as fetal bovine serum (FBS) and trypsin, are important supplements for scientific, pharmaceutical, and medical use. Although preventive guidelines and tests are implemented to reduce potential viral contamination in these biologicals, they do not target unusual or emerging viruses, leading to safety concerns. Using unbiased metagenomics, we investigated the presence of viruses in recently collected commercial FBS and trypsin samples from different geographic regions. In total, we detected viral sequences belonging to Parvoviridae,Anelloviridae,Flaviviridae, Herpesviridae,Caliciviridae,Nodaviridae,Rhabdoviridae, and Paramyxoviridae, including several viruses related to bovine diseases, viruses of potential human and insect origin, and viruses of unknown origin. Bovine parvovirus 3 and bosavirus were detected with high frequency and abundance in FBS, necessitating more stringent testing for these parvoviruses during production. Both bovine norovirus and bovine viral diarrhea virus 1 displayed relatively high genetic distance to closest hits, indicating the presence of new genotypes in farm animals. While the origin of novel lyssavirus and Nipah virus is unclear, their presence raises the possibility of the introduction of pathogenic animal-derived viruses into biologicals. Our results showed relatively widespread contamination of different viruses in biologicals, underscoring the need for robust safety protocol alternatives, such as metagenomic sequencing, to monitor emerging viruses.

Electrochemical DNA/aptamer biosensors based on SPAAC for detection of DNA and protein

Electrochemical DNA/aptamer (E-DNA/aptamer) biosensors based on target-induced change in conformation of surface-anchored oligonucleotides have been developed in recent years. In order to improve electrode surface modification versatility, we developed a simple approach for fabrication of DNA-conjugated electrochemical platform on screen-printed electrodes for the detection of DNA and protein. The conjugation of oligonucleotides was conducted based on a copper-free strain-promoted azide-alkyne cycloaddition (SPAAC), in which the dibenzocyclooctyne (DBCO)-modified oligonucleotides were covalently conjugated to azide-terminated gold-plated screen-printed carbon electrodes. As a proof-of-principle, we employed the p53 DNA probe and anti-VEGF165 DNA aptamer as the receptors to determine the versatility of the electrode surface modification. The proposed E-DNA/aptamer sensors showed a limit of detection of 0.76 nM for p53 DNA target and 8.2 pM for VEGF165 protein, respectively. In addition, both sensors demonstrated satisfactory stability in 50% fetal bovine serum samples. The results indicated that the E-DNA/aptamer sensors fabricated by SPAAC reaction performed well when compared to those fabricated via the conventional gold-thiol coadsorption or CuAAC reaction. The proposed approach has a great potential to fabricate biosensors on less-expensive substrates for detection of DNA or proteins.

Graphene Quantum Dot‐poly(L‐lysine)‐gold Nanoparticles Nanocomposite for Electrochemical Determination of Dopamine and Serotonin

AbstractA nanocomposite consists of AuNPs, GQD, and poly(L‐lysine) was prepared for highly sensitive electrochemical determination of dopamine (DA) and serotonin (5‐HT) neurotransmitters which are of vital importance in neurological disorders. The P(L‐Lys) GQD was successfully obtained a one‐step co‐electrodeposition of GQD and L‐Lys on the PGE. The electrochemical behaviors of DA and 5‐HT were analyzed via DPV and CV. LOD values for DA and 5‐HT were calculated as 0.03 μM and 0.017 μM, respectively. Also, the DA and 5‐HT contents were determined at the PGE/AuNPs/P(L‐Lys)‐GQD in fetal bovine serum samples and pharmaceutical formulations, and high recovery values were obtained.

An isothermal, non-enzymatic, and dual-amplified fluorescent sensor for highly sensitive DNA detection

Abstract Sensitive DNA assays are of importance in life science and biomedical engineering, but they are heavily dependent on thermal cycling programs or enzyme-assisted schemes, which require the utilization of bulky devices and costly reagents. To circumvent such requirements, we developed an isothermal enzyme-free DNA sensing method with dual-stage signal amplification ability based on the coupling use of catalytic hairpin assembly (CHA) and Mg2+-dependent deoxyribozyme (DNAzyme). In this study, the sensing system involves a set of hairpin DNA probes for CHA (ensuring the first stage of signal amplification) as well as ribonucleobase-modified molecular beacons that serve as activatable substrates for DNAzymes (warranting the second stage of signal amplification). An experimentally determined detection limit of about 0.5 pM is achieved with a good linear range from 0.5 to 10 pM. The results from spiked fetal bovine serum samples further confirm the reliability for practical applications. The non-thermal cycling, enzyme-free, and dual-amplified features make it a powerful sensing tool for effective nucleic acid assay in a variety of biomedical applications.

Synthesis of red photoluminescent nickel doped self-assembled copper nanoclusters and their application in biothiol sensing

Copper nanoribbons (Cu NRs) and Ni-doped copper nanowires (Cu NWs) with red photoluminescent (PL) were prepared and employed for detection of biothiol. Using 4-(trifluoromethyl) thiophenol as both reducing agent and protecting ligand, the copper nanoclusters (Cu NCs) were synthesized and assembled to nanoribbons. And the Cu NCs were assembled to nanowires by adding nickel ion precursor in synthetic process. The Cu NWs with 3% Ni doping showed a 3-fold emission enhancement than Cu NRs, and the absolute quantum yield was obviously increased from 4.53% to 19.76%. The doped Ni induced Ni-Cu metallophilic interaction, which facilitated the radiative relaxation of excited electrons and furtherly resulted in stronger PL emitting. The morphologies, composition, electronic states, geometrical configuration and arrangement of Cu NCs in assembled architecture were studied by experimental and theoretical investigation. Moreover, the PL of Cu NCs assembly was sensitive to cysteine, homocysteine, and glutathione attributed to surface ligands exchange of Cu NCs through interaction between metal and sulfydryl group. Therefore, a rapid, sensitive, and selective sensing strategy for detection of biothiol was proposed. And the PL test strips based on Cu NCs assembly were fabricated for visual detection of biothiol. Finally, the practical application of sensing system and PL test strips were verified in fetal bovine serum samples spiked with cysteine and homocysteine.

The Preparation of CuInS2-ZnS-Glutathione Quantum Dots and Their Application on the Sensitive Determination of Cytochrome c and Imaging of HeLa Cells.

Cytochrome c (Cyt c), one of the most significant proteins acting as an electron transporter, plays an important role during the transferring process of the energy in cells. Apoptosis, one of the major forms of cell death, has been associated with various physiological regularity and pathological mechanisms. It was found that Cyt c can be released from mitochondria to cytosol under different pathological conditions, triggering subsequent cell apoptosis. Herein, we developed a fluorescence nanoprobe based on negatively charged CuInS2-ZnS-GSH quantum dots (QDs) for the sensitive determination of Cyt c. CuInS2-ZnS-GSH QDs with high photochemical stability and favorable hydrophilicity were prepared by a simple hot reflux method and emit a bright orange-red light. The electron-deficient heme group in Cyt c is affiliated with the electron-rich CuInS2-ZnS-GSH QDs through the photo-induced electron transfer process, resulting in a large decrease in fluorescence intensity of QDs. A good linearity for concentration of Cyt c in the range of 0.01–7 μmol L–1 is obtained, and the detection limit of Cyt c is as low as 1.1 nM. The performance on the detection of Cyt c in spiked human serum and fetal bovine serum samples showed good recoveries from 85.5% to 95.0%. Furthermore, CuInS2-ZnS-GSH QDs were applied for the intracellular imaging in HeLa cells showing an extremely lower toxicity and excellent biocompatibility.

AI powered electrochemical multi-component detection of insulin and glucose in serum

Multi-component detection of insulin and glucose in serum is of great importance and urgently needed in clinical diagnosis and treatment due to its economy and practicability. However, insulin and glucose can hardly be determined by traditional electrochemical detection methods. Their mixed oxidation currents and rare involvement in the reaction process make it difficult to decouple them. In this study, AI algorithms are introduced to power the electrochemical method to conquer this problem. First, the current curves of insulin, glucose, and their mixed solution are obtained using cyclic voltammetry. Then, seven features of the cyclic voltammetry curve are extracted as characteristic values for detecting the concentrations of insulin and glucose. Finally, after training using machine learning algorithms, insulin and glucose concentrations are decoupled and regressed accurately. The entire detection process only takes three minutes. It can detect insulin at the pmol level and glucose at the mmol level, which meets the basic clinical requirements. The average relative error in predicting insulin concentrations is around 6.515%, and that in predicting glucose concentrations is around 4.36%. To verify the performance and effectiveness of the proposed method, it is used to determine the concentrations of insulin and glucose in fetal bovine serum and real clinical serum samples. The results are satisfactory, demonstrating that the method can meet basic clinical needs. This multi-component testing system delivers acceptable detect limit and accuracy and has the merits of low cost and high efficiency, holding great potential for use in clinical diagnosis.

Impedimetric aptasensor for lysozyme detection based on carbon nanofibres enriched screen-printed electrodes

In this study, lysozyme (LYS) detection was realized by impedimetric aptasensor that consist of aptamer immobilized carbon nanofibres modified screen printed electrodes (CNF-SPEs). Under this aim, NH2-functionalized LYS-specific aptamer was immobilized to surface of CNF-SPEs via passive adsorption. The step-by-step fabrication process of the aptasensor and the detection of LYS was performed. During the aptasensor fabrication primarily electrochemical characterization was done via cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. Aptamer-LYS complex formation caused prevention of electron transfer reaction on the interface and thus charge transfer resistance (Rct) increased. Based on this phenomenon, LYS could be quantitatively detected in accordance with the change at Rct values obtained by EIS in the presence of [Fe(CN)6]3–/4– while increasing LYS concentration. Under optimum conditions, the detection limit of the aptasensor was found to be 0.36 µg/mL. The proposed aptasensor was also used for the determination of LYS in fetal bovine serum samples with a detection limit of 1.89 µg/mL. Our assay in combination with the eight-channel array of electrodes was also used for LYS detection to present its implementation to nucleic acid-based array system.

Rapid Response and High Selectivity for Reactive Nitrogen Species Based on Carbon Quantum Dots Fluorescent Probes

Reactive nitrogen species (RNS) are vital signaling molecules involved in most physiological and pathological processes. Within RNS, nitric oxide (NO) and its metabolite nitrite (NO2−) have been widely applied in medicinal, food, and environmental fields. However, at present, the methods of detecting RNS by fluorescence quenching through chemical reactions have disadvantages, such as long reaction time and weak anti-interference ability. In response to these existing problems, we have developed a novel fluorescent probe, namely, carbon quantum dots (CDs) that are passivated by benzylamine. The obtained CDs (named B-CDs) possess excellent down- and upconversion properties. In particular, upconversion is used to sensitively and selectively measure NO and NO2− under different pH conditions in aqueous media via two different mechanisms (static and dynamic quenching). At pH 7.4, the nanomolar concentration of NO, produced from sodium nitroprusside (SNP) in a concentration-dependent manner, can be rapidly detected with a correlation coefficient (R2) greater than 0.99. Similarly, the quantitative detection of NO2− at pH 1.6 also shows a good linear relationship with a linear range of 0–14 μM, and a limit of detection (LOD) that is as low as 43 nM and 0.65 μM at excitation wavelengths of 800 nm and 375 nm, respectively. Notably, this probe stands out due to its extremely short response time and outstanding selectivity and anti-interference ability against a variety of common interfering substances, while realizing the fast and highly selective and sensitive detection of NO and NO2−. Finally, this probe has been successfully applied to the sensing of NO in fetal bovine serum (FBS) samples and NO2− in milk and tap water samples.

A turn‐on fluorescence assay for heparin based on DNA‐templated gold nanoclusters via ET

AbstractA novel fluorescence turn‐on assay for heparin has been developed based on DNA‐templated gold nanoclusters (AuNCs) and Cytochrome c (Cyt c). In the design, poly A (A15) ssDNA was selected as a template for fabricating AuNCs. AuNCs possess strong fluorescence emission at 471 nm. Upon addition of Cyt c, the fluorescence of AuNCs was quenched effectively by electron transfer (ET) between AuNCs and the heme cofactor of Cyt c. In the presence of heparin, the much higher electrostatic binding of heparin to Cyt c caused Cyt c to be away from AuNCs, leading to a recovery of fluorescence intensity of AuNCs. The proposed method was found to be simple, fast, and sensitive for heparin detection, with a linear range from 0.5 μg/mL to 12 μg/mL, and a detection limit of 0.15 μg/mL. Furthermore, this work was successfully applied to detection of heparin in fetal bovine serum samples, with good recoveries from 93.53% to 103.6%.

Hydro-soluble NIR fluorescent probe with multiple sites and multiple excitations for distinguishing visualization of endogenous Cys/Hcy, and GSH

Small molecular biothiols (Cys, Hcy, and GSH) are intimately related to complicated metabolic process. On account of the analogous chemical construction and reactivity, it is still a challenging problem to diacritically detect biothiols, which seriously hinders people's understanding of their metabolic relationship and the reasons for biothiols-related illnesses. Therefore, a hydro-soluble NIR fluorescent probe (YF) with multiple sites and multiple excitations was designed for distinguishing biothiols. Across different excitation, YF displayed unique fluorescence signals: λex = 418 nm, λem = ∼496 nm; λex = 517 nm, λem = ∼576/733/783 nm; λex = 558 nm, λem = ∼611/733 nm, respectively. As far as we know, the different reaction mechanism that leading to different spectroscopic behaviors of YF towards biothiols were confirmed by DFT calculation for the first time. Significantly, YF was successfully applied to recognize Cys/Hcy, and GSH in A375 cells from different emission channels, and was determination of biothiols in fetal bovine serum samples and the result was in good agreement with that tested by Ellman method.

Highly sensitive detection of cancer cells via split aptamer mediated proximity-induced hybridization chain reaction

Highly sensitive detection of cancer cells is of great importance for evaluating cancer development and improving survival rates. Here, we developed a split aptamer mediated proximity-induced hybridization chain reaction (HCR) strategy to meet this purpose. In this strategy, two split aptamer initiator probes, Sp-a and Sp-b, and two HCR hairpin probes, H1 and H2 were designed. The split aptamer initiator probes contained two components, split aptamer domains being responsible for target recognition, and the split initiator parts serving as the HCR promoter. In the presence of target cells, Sp-a and Sp-b would self-assemble on the cell surfaces, allowing the formation of an intact nicked initiator to activate the HCR reaction. Benefit from low background split aptamers and HCR amplification, this strategy presented high sensitivity in quantitative detection with a detection limit of 18 cells in 150 μL of binding buffer. Moreover, the approach exhibited excellent specificity to target cells in 10% fetal bovine serum and mixed cell samples, which was favorable for clinical diagnosis in complex biological environment. In addition, by changing the split aptamers attached to the split initiator, the proposed strategy can be expanded to detect various kinds of target cells. It may provide a novel and useful applicable platform for the sensitive detection of cancer cells in biomedicine and tumor-related studies.

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.

Identification and characterization of pestiviruses isolated from individual fetal bovine serum samples originated in Rio Grande do Sul state, Brazil

ABSTRACT: The identification of diversity of bovine pestiviruses circulating in the field is fundamental for continuous evaluation of diagnostic tests and vaccine composition. In this article we performed the genetic and antigenic characterization of twelve bovine pestiviruses isolated in the western region of Rio Grande do Sul, Brazil. The viruses were isolated from sera of bovine fetuses or from animals with clinical presentations suggestive of pestivirus infection. Genetic characterization by sequencing and phylogenetic analysis of the 5’UTR region of the viral genome allowed for the identification of bovine viral diarrhea virus (BVDV-1a, 4/12, 33.3%), BVDV-1b (6/12, 50%) and BVDV-2 (2/12, 16.7%). The reactivity of the isolates with a panel of monoclonal antibodies raised against envelope proteins (Erns, E1 and E2) demonstrated a high antigenic variability among isolates. Thus, the active circulation of bovine pestivirus infection, with high genetic and antigenic variability, in cattle on the western border of RS was confirmed, demonstrating the importance of continuous characterization of the pestiviruses circulating in the cattle herds to keep the diagnostic and control measures up to date.