Oral Fluid Samples Research Articles

Environmentally friendly screen-printed electrodes for the selective detection of 4-bromo-2,5-dimethoxyphenethylamine (2C-B) in forensic analysis.

In response to the growing need for sustainable analytical methods, this study explores the repurposing of screen-printed electrodes (SPEs) that would otherwise be discarded. This involves recoating the working electrode surface with a graphite (Gr) and chitosan (CTS) dispersion, creating a reusable SPE (SPE-Gr/CTS). Demonstrating its utility, SPE-Gr/CTS was employed for the detection of 4-bromo-2,5-dimethoxyphenethylamine (2C-B), a phenylethylamine commonly used for recreational proposes. Identifying 2C-B in fluid oral and seized samples is of great interest for forensic and toxicological applications. The 2C-B detection using SPE-Gr/CTS was optimized in Britton-Robinson buffer solution (0.1 mol L-1) at pH 2.0, employing square-wave adsorptive stripping voltammetry. The electrochemical behavior of 2C-B on SPE-Gr/CTS exhibited one irreversible oxidation and a reversible redox process. The proposed method presented a dynamic linear range for 2C-B determination (0.05 to 7.5 μmol L-1) with a low LOD (0.015 μmol L-1). Moreover, the stability of 2C-B electrochemical responses on SPE-Gr/CTS was confirmed using the same or different electrodes (N = 3), with a relative standard deviation of less than 5.0%. Interference studies with seventeen other illicit drugs and adulterants demonstrated that the proposed method is selective for 2C-B detection even in the presence of these substances. Real seized and oral fluid samples containing 2C-B were analyzed using this method, and the results were confirmed by LC-MS. The proposed device demonstrates to be an environmentally friendly and selective sensor for 2C-B detection in forensic analysis, offering a rapid and straightforward screening method for seized and biological samples. In addition, a portable and sensitive determination of 2C-B in forensic samples is presented with minimal sample consumption (50 μL).

Validation of an LC-MS/MS Method for Analysis of 58 Drugs of Abuse in Oral Fluid and Method Comparison with an Established LC-HRMS Method.

Liquid chromatography-mass spectrometry (LC-MS) methods for detection of multiple drugs of abuse (DoA) in oral fluid (OF) samples are being implemented in many clinical routine laboratories. Therefore, there is a need to develop new multi-analyte methods with simple sample pre-treatment and short analysis times. The purpose of this work was to validate a method detecting 58 DoA to be used with two different OF sampling kits, the saliva collection system (SCS) from Greiner Bio-One and Quantisal from Immunalysis, using the same sample pretreatment and analytical method. A set of 110 samples collected with the SCS kit was further compared to an LC-HRMS (high resolution mass spectrometry) method in another laboratory. The method was successfully validated, with precision and accuracy of ≤15% and z-scores of <2 for external controls. Using a sensitive LC-MS/MS instrument, the detection limits were <1 µg/L in neat oral fluid. In the comparative study between the LC-MS/MS and LC-HRMS methods using SCS samples, a good agreement was observed. Discrepancies were limited to lower concentration ranges, attributable to differences in cut-off thresholds between the methods. This work contributes to the development of LC-MS multi-analyte methods for OF samples, which are suitable for clinical routine laboratories.

Determination of endogenous GHB in ante-mortem whole blood, urine, and oral fluid by LC–MS/MS: The effect of different additives and storage conditions on the stability of GHB in blood

Two challenges in detecting γ-hydroxybutyric acid (GHB) intake are its endogenous presence and in vitro production after sampling. This study developed an LC–MS/MS method for selective GHB determination in human antemortem blood, urine, and oral fluid at endogenous concentrations. Furthermore, the stability of GHB in blood samples and its endogenous concentrations in samples taken under controlled circumstances were investigated. Samples were extracted in methanol/acetonitrile and processed by anion exchange solid-phase extraction. GHB was separated from structural isomers using a reversed–phase LC column with anion properties. The validated limit of quantification was 0.005 µg/mL in blood and 0.010 µg/mL in urine and oral fluid, at which the relative reproducibility standard deviation and bias were <15 %. The mean extraction recovery was ≥90 %. The average GHB concentration increased by 1.2 µg/mL in fluoride/citrate- preserved blood after 28 days of storage at 4°C; however, in fluoride/oxalate (FX)-preserved blood, the mean concentration increased by only 0.055 µg/mL. No change was observed at −20°C. In 105 randomly selected samples of FX-preserved blood collected for forensic antemortem toxicological analysis, all concentrations were <0.066 µg/mL, even after long-term storage at −20°C. In blood, urine, and oral fluid samples from a clinical study of GHB intake, endogenous baseline levels from 30 participants ranged from 0.0069–0.050, 0.024–0.38, and 0.034–0.93 µg/mL, respectively. These results demonstrate that the current cut-off level of 5 µg/mL for discriminating between endogenous and exogenous GHB in antemortem blood could be considerably lower for FX-preserved blood stored at −20°C.

Development of a concentration method for simple and sensitive detection of SARS-CoV-2 in saliva using a magnetic nanoparticle kit

BackgroundWhen diagnosing viral infections in humans and animals, the presence of virus in a sample in trace amounts that are below the analytical sensitivity of the detection system may cause false negative results and inaccurate diagnosis. We previously reported the development of a simple virion concentration technique using 12 ml large-volume samples that can dramatically improve diagnostic sensitivity by increasing analytical sensitivity by 100-fold over conventional methods. The present study was conducted to further improve the simplicity and versatility of this method. We constructed a simple and highly sensitive method for the detection of SARS-CoV-2 in human saliva after concentration using a magnetic nanoparticle conjugated with polyethylene glycol (PEG). ResultsPerformance of the method was evaluated by comparing a combination of automated nucleic acid extraction and RT-qPCR or triplex RT-LAM detection in a spiked sample of 20 ml saliva collected from healthy humans. The method theoretically achieved 300-fold concentration of spiked SARS-CoV-2 in saliva, enabling 10- to 1000-fold higher analytical sensitivity for detection compared to conventional RNA extraction methods. ConclusionsThis newly developed method allows for easy and reliable concentration of the virion in less than 60 min, improving the analytical sensitivity of the SARS-CoV-2 test. Further, the method allows for easy and reliable enrichment of the virus in less than 60 min, improving the analytical sensitivity of the SARS-CoV-2 test. This method is easily used for highly sensitive virus detection from a variety of human oral fluid samples and may also be applied to rapid and labor-saving screening tests by pooling a large number of samples.

Changes in heavy metal levels in the oral fluid of young patients with and without plaque-induced gingivitis undergoing treatment with braces

Relevance. Research into the effects of nickel-titanium alloys and heavy metal ions on the development of inflammatory oral diseases is becoming increasingly significant in orthodontics. The relationship between toxic elements and inflammatory responses remains under-researched and controversial. Data on the connection between heavy metals and inflammatory reactions could influence the choice of orthodontic appliance materials and guide the subsequent management and monitoring of patients with braces. The question of the safe use of nickel-titanium alloy braces continues to be a relevant concern.Purpose. To assess the levels of heavy metals in the oral fluid of young patients with braces, both in those who developed plaque-induced gingivitis and those who did not.Materials and Methods. The study involved 50 clinically healthy patients (Groups I and II health categories) with intact teeth, including patients with compensated dental caries (isolated carious lesions – Grade I) and no periodontal diseases (PMA index &lt;20), presenting with dental crowding and malocclusion (K07.2, K07.3). The average age of the patients was 22.1 ± 2.7 years, all of whom were undergoing treatment with metal braces. Oral fluid samples were analyzed for 12 heavy metal elements using inductively coupled plasma mass spectrometry (ICP-MS) in a laboratory setting. Additionally, lysozyme activity and oral fluid pH were measured before appliance placement and six months into orthodontic treatment.Results. Adaptation to braces in young patients is frequently complicated by the development of gingivitis and periodontitis due to impaired oral hygiene and the mechanical pressure exerted on teeth and gums, leading to elemental imbalances. Patients with gingivitis during orthodontic treatment are particularly at risk of developing such imbalances and therefore require timely correction of their mineral metabolism.

Extraction of synthetic cathinones from biological samples: A systematic review

Analysis of biological samples containing synthetic cathinones has become a significant area of interest for researchers in recent years, because synthetic cathinones can cause adverse reactions such as delusions and hallucinations. Generally, the intricate nature of the sample matrix and exceedingly low drug concentration in biological samples present significant challenges for the determination of target substances. Accordingly, scientists were dedicated to the advancement of effective sample preparation techniques to address these difficulties. However, the current reviews involved in synthetic cathinones all focused on detection methods. A systematic review focusing on sample preparation for the quantification of synthetic cathinones is still lacking. In light of that, this paper reviewed the most commonly used sample preparation techniques for synthetic cathinones. Recent advances in sample preparation techniques for synthetic cathinones in different biological samples such as blood, urine, oral fluid and hair samples were discussed. In addition, we prospected the challenges and the future perspectives of biological sample preparation techniques for synthetic cathinones determination.

Assessment of real-time PCR test in oral fluid samples for screening the serotypes of Actinobacillus pleuropneumoniae circulating in swine herds

Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, causing remarkable economic losses in the global swine industry. The diversity of A. pleuropneumoniae is generally determined through serotype identification, which is commonly employed for control strategies and surveillance. However, serological methods currently in use still have significant limitations. This study explores the use of real-time polymerase chain reaction (qPCR) to detect circulating serotypes of A. pleuropneumoniae in non-diseased swine herds through testing of oral fluids.The study included three A. pleuropneumoniae-positive and three A. pleuropneumoniae-negative farms located in Quebec, Canada. Tonsil brushings, microbiological growths, and oral fluids were analyzed using qPCR to detect A. pleuropneumoniae and its distinct serotypes. Serological tests were performed using the LPS ELISA available at that time. In negative farms the absence of A. pleuropneumoniae and any serotype confirmed the specificity of the method. Positive farms, on the other hand, confirmed also the sensitivity of the analysis, with oral fluid samples consistently yielding positive results for the serotypes identified by ELISA.The qPCR test conducted on oral fluids offers a noninvasive and cost-effective method for monitoring, complementing traditional serological techniques. It provides qualitative information about serotype distribution, facilitating proactive surveillance and control strategies.

Bar adsorptive microextraction and liquid chromatography-diode array detection of synthetic cannabinoids in oral fluid

In recent years, synthetic cannabinoids (SCs) have become a major public health issue. For this reason, there is a need for innovative analytical methods that allow its monitoring in biological matrices. In this work, we propose a novel methodology to screen eight SCs (AM-694, cumyl-5F-PINACA, MAM-2201, 5F-UR-144, JWH-018, JWH-122, UR-144 and APINACA) in oral fluids. A bar adsorptive microextraction method followed by microliquid desorption combined with high-performance liquid chromatography with diode array detection (BAµE-µLD/HPLC-DAD) was developed to monitor the target SCs. The main factors affecting the BAµE technology were fully optimized for oral fluid analysis. Under optimized experimental conditions, the proposed methodology showed good linear dynamic ranges from 20.0 to 2000.0 µg L−1 (r2 > 0.99, relative residuals < 15%), limits of detection between 2.0 and 5.0 µg L−1 and suitable average recovery yields (87.9–100.5%) for the eight studied SCs. The intra- and interday accuracies (bias ≤ ± 14.7%) and precisions (RSD ≤ 14.9%) were also evaluated at three spiking levels. The validated methodology was then assayed to oral fluid samples collected from several volunteers. The proposed analytical approach showed remarkable performance and could be an effective alternative for routine monitoring of the target compounds in oral fluid.Graphical

Suitability of undenatured ethanol for DNA and RNA preservation in pig oral fluid and fecal samples used for PCR-based pathogen detection

Suitability of undenatured ethanol for DNA and RNA preservation in pig oral fluid and fecal samples used for PCR-based pathogen detection

Supplementary Material: Suitability of undenatured ethanol for DNA and RNA preservation in pig oral fluid and fecal samples used for PCR-based pathogen detection

Supplementary Material: Suitability of undenatured ethanol for DNA and RNA preservation in pig oral fluid and fecal samples used for PCR-based pathogen detection

Substance use and driver fatality in Norway: An expanded case-control study.

Using alcohol or psychoactive drugs before driving a motor vehicle may increase the risk of crash involvement, injury, and death. This is better documented for alcohol than for drugs. The aim of this study was to expand a previous case-control study on substance use and driver fatality by doubling the number of cases and controls, and hence improve the statistical power and enable the analysis of combined substance use. We collected data on alcohol and drug use from all 1197 drivers of cars and vans who were fatally injured in road traffic crashes in Norway between 2005 and 2020 ('cases') by analyzing blood samples or reviewing other information on substance use. We also collected data on alcohol and drug use among 17,219 drivers in random road traffic ('controls') by analyzing oral fluid samples. Substance use was converted to dichotomous variables (no use/use). We used unconditional logistic regression to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs) of driver fatality for mutually exclusive substance groups, adjusted for sex, age, geographic region, urban centrality class, and time interval of the week. Compared to no substance use, the aOR (95% CI) for driver fatality was for alcohol 91 (61-137), stimulants (primarily amphetamines) aOR 22 (9-56), benzodiazepines and z-hypnotics (BZDs) aOR 4.0 (2.7-5.9), tetrahydrocannabinol (THC) aOR 3.4 (1.7-6.7), and opioids aOR 1.4 (0.4-4.9). The aOR for any polysubstance use was 168 (96-297). The combinations of BZDs with stimulants or THC were associated with markedly higher aORs for driver fatality than the use of single substance groups. Alcohol and polysubstance use are the most important predictors of fatal injury, followed by stimulants.

Detection and quantification of selected cannabinoids in oral fluid samples by protein precipitation and LC-MS/MS

Cannabis is the most widely consumed illicit drug worldwide. As consumption rates increase, partially due to the decriminalization of its use for medicinal and recreational purposes, analytical methods for monitoring different cannabinoids in several biological matrices have been developed. Herein, a simple and fast extraction procedure to extract natural cannabinoids from oral fluid (OF) samples was developed and fully validated according to the ANSI/ASB 2019 Standard Practices for Method Validation in Forensic Toxicology. Using only 0.2 mL of neat OF, the analytes [Δ9-tetrahidrocannabinol (THC), 11-hydroxy-Δ9-tetrahydrocannabinol (THC-OH), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), cannabinol (CBN) and cannabidiol (CBD)] were extracted by protein precipitation with a mixture of methanol:acetonitrile (80:20, v/v); the extracts were centrifuged, evaporated to dryness and reconstituted in 100 µL of methanol. Analysis was performed by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). The developed methodology produced linear results for all compounds, with working ranges of 0.1–50 ng/mL for THC, 0.5–50 ng/mL for THC-OH, CBN and CBD, and 0.05–1 ng/mL for THC-COOH. Ion suppression was observed for THC, CBN and CBD, which did not impair sensitivity considering the low limits of quantification (LOQs) and limits of detection (LODs) obtained (which varied between 0.05 and 0.5 ng/mL). The extraction procedure produced great recoveries, and the compounds were stable. No interferences were found, and the method proved to be extremely fast, selective, precise, and accurate for use in routine analysis. The method was successfully applied to authentic samples.

The multi-modal sensory effect on sour taste perception during oral processing of starch-thickened fluids

Sour taste is one of the fundamental taste attributes and considered as a saliva secretion stimulant facilitating consumers with xerostomia and swallowing difficulties. The dynamic sour taste perception during oral processing of starch-thickened fluid was therefore investigated in this study. Recruited healthy subjects were divided into those with high (H_AMS) and low (L_AMS) salivary α-amylase activity groups and their temporal dominant sensory evaluation were analyzed while oral processing starch-thickened fluid samples with different concentration of citric acid. By simultaneously evaluating the physical and chemical properties of subjects' expectorated fluid/saliva mixtures, the complex and multi-modal interplay between fluid viscosity (tactile perception), citric acid concentration (taste perception), salivary α-amylase activity (binary taste interaction) was successfully demonstrated. The sour taste perception was found to be greatly affected by the continuous starch-thickened fluid hydrolysis by salivary α-amylase, resulting in a gradual production of sweet-tasting oligosaccharides and simultaneous decrease in fluid viscosity, and group variations (H_AMS vs. L_AMS) were pronouncedly observed in the hydrolyzed oligosaccharide concentrations (glucose, maltose, and maltotriose) which suitably corresponded to the selected dominant sensory attributes including perceived taste differences and taste dominant duration. These findings suggest that salivary biochemical properties and the thickened fluid type greatly influence consumers’ sensory perception. This could provide valuable insights for designing and optimizing thickened foods and beverages that are palatable in sensory properties and meet the needs of special consumers.

QuEChERS Extraction and Simultaneous Quantification in GC-MS/MS of Hexahydrocannabinol Epimers and Their Metabolites in Whole Blood, Urine, and Oral Fluid.

Recently, hexahydrocannabinol (HHC) was posed under strict control in Europe due to the increasing HHC-containing material seizures. The lack of analytical methods in clinical laboratories to detect HHC and its metabolites in biological matrices may result in related intoxication underreporting. We developed and validated a comprehensive GC-MS/MS method to quantify 9(R)-HHC, 9(S)-HHC, 9αOH-HHC, 9βOH-HHC, 8(R)OH-9(R)-HHC, 8(S)OH-9(S)HHC, 11OH-9(R)HHC, 11OH-9(S)HHC, 11nor-carboxy-9(R)-HHC, and 11nor-carboxy-9(S)-HHC in whole blood, urine, and oral fluid. A novel QuEChERS extraction protocol was optimized selecting the best extraction conditions suitable for all the three matrices. Urine and blood were incubated with β-glucuronidase at 60 °C for 2 h. QuEChERS extraction was developed assessing different ratios of Na2SO4:NaCl (4:1, 2:1, 1:1, w/w) to be added to 200 µL of any matrix added with acetonitrile. The chromatographic separation was achieved on a 7890B GC with an HP-5ms column, (30 m, 0.25 mm × 0.25 µm) in 12.50 min. The analytes were detected with a triple-quadrupole mass spectrometer in the MRM mode. The method was fully validated following OSAC guidelines. The method showed good validation parameters in all the matrices. The method was applied to ten real samples of whole blood (n = 4), urine (n = 3), and oral fluid (n = 3). 9(R)-HHC was the prevalent epimer in all the samples (9(R)/9(S) = 2.26). As reported, hydroxylated metabolites are proposed as urinary biomarkers, while carboxylated metabolites are hematic biomarkers. Furthermore, 8(R)OH-9(R)HHC was confirmed as the most abundant metabolite in all urine samples.

First Report of Porcine Parvovirus 8 in Europe: Widespread Detection and Genetic Characterization on Commercial Pig Farms in Hungary and Slovakia.

Porcine parvovirus 8 (PPV8), a novel virus in the Parvoviridae family, was first identified in 2022 in lung samples of domestic pigs from China. Retrospective analyses showed that it had been circulating in China since 1998, but no other countries had reported its presence so far. A recent study conducted in South America did not detect any PPV8-positive samples in that region. Here, we report the detection of PPV8 in Hungarian and Slovakian pig farms and the estimated prevalence of the virus in Hungary. Altogether, 2230 serum, 233 oral fluid, and 115 processing fluid samples were systematically collected from 23 Hungarian and 2 Slovakian pig farms between 2020 and 2023. A real-time quantitative PCR method was developed to detect the viral genome. Our results revealed the presence of PPV8 on 65% of the Hungarian farms and both Slovakian farms included in our study, marking its first detection in Europe. Oral fluid samples showed the highest positivity rates, reaching up to 100% in some herds. The viral genome was successfully detected in serum and processing fluid samples too, but with significantly lower prevalence rates of 4% and 5%, respectively. Genetic analysis of 11 partial VP2 sequences demonstrated high similarity to the original Chinese strain but with unique amino acid mutations, suggesting possible local evolution of the virus. Our study presents the first scientific evidence of PPV8 infection outside of China and offers a comprehensive assessment of its prevalence in the Hungarian pig population. Further research is required to understand its potential impact on swine health.

A phase 3 randomised double-blind placebo-controlled trial of mirtazapine as a pharmacotherapy for methamphetamine use disorder: a study protocol for the Tina Trial

BackgroundThere are no approved pharmacotherapies for methamphetamine use disorder. Two preliminary phase 2 randomised controlled trials have found mirtazapine, a tetracyclic antidepressant, to be effective in reducing methamphetamine use. The proposed Tina Trial is the first phase 3 placebo-controlled randomised trial to examine the effectiveness and safety of mirtazapine as an outpatient pharmacotherapy for methamphetamine use disorder.MethodsThis is a multi-site phase 3 randomised, double-blind, placebo-controlled parallel trial. Participants are randomly allocated (1:1) to receive either mirtazapine (30 mg/day for 12 weeks) or matched placebo, delivered as a take-home medication. The target population is 340 people aged 18–65 years who have moderate to severe methamphetamine use disorder. The trial is being conducted through outpatient alcohol and other drug treatment clinics in Australia. The primary outcome is measured as self-reported days of methamphetamine use in the past 4 weeks at week 12. Secondary outcomes are methamphetamine-negative oral fluid samples, depressive symptoms, sleep quality, HIV risk behaviour and quality of life. Other outcomes include safety (adverse events), tolerability, and health service use. Medication adherence is being monitored using MEMS® Smart Caps fitted to medication bottles.DiscussionThis trial will provide information on the safety and effectiveness of mirtazapine as a pharmacotherapy for methamphetamine use disorder when delivered as an outpatient medication in routine clinical practice. If found to be safe and effective, this trial will support an application for methamphetamine use disorder to be included as a therapeutic indication for the prescription of mirtazapine.Trial registrationAustralian and New Zealand Clinical Trials Registry ACTRN12622000235707. Registered on February 9, 2022.

Quantification of antidepressants in oral fluid and plasma samples using microextraction by packed sorbent and analysis by gas chromatography-tandem mass spectrometry

The consumption of antidepressants is extremely significant as they are a class of medications widely used in the treatment of numerous disorders and are therefore considered a public health problem throughout the world. The aim of this work was to develop and optimize two methodologies for the determination of selected antidepressants and metabolites (fluoxetine, venlafaxine, O-desmethylvenlafaxine, citalopram, sertraline, paroxetine), in 250 µL of sample (oral fluid and plasma) using microextraction by packed sorbent (MEPS) as the extraction technique and gas chromatography coupled to tandem mass spectrometry (GC–MS/MS) for analysis. The two methods were fully validated considering the internationally accepted criteria for bioanalytical procedures, presenting linearity within the studied range, with limits of quantification between 10 and 100 ng/mL, coefficients of determination (R2) of at least 0.99 and precision and accuracy with acceptable values of coefficients of variation and relative errors for all antidepressants in study and for both specimens. Recoveries ranged between approximately 12 and 93 % for oral fluid samples and between approximately 28 and 101 % for plasma samples. To our best knowledge, the described methods are the first to be reported using MEPS and GC–MS/MS for the identification of antidepressants in oral fluid and plasma samples, proving to be sensitive, simple, fast and capable of being applied in routine clinical and forensic toxicology scenarios.

Simultaneous chemo- and enantio-separation of 2-, 3- and 4-chloro-methcatinones by high-performance liquid chromatography-tandem mass spectrometry and its application to oral fluid samples

A method of analysis was developed for the simultaneous chemo- and enantioseparation of 2-, 3-, and 4-chloromethcathinones by high-performance liquid chromatography tandem mass-spectrometry. The fast method enables the reliable identification of positional isomers of chloromethcathinones in biological samples. In addition, the same method can be used for the enantioselective quantitative determination of one of these compounds and its major phase-1 metabolites in biological fluids. The developed method was applied to oral fluid samples collected by police during routine random traffic control in Belgium from January to November, 2023. It was found that 3-CMC was more frequently abused compared to 4-CMC. Although some differences were observed between the concentrations of enantiomers in OF, most likely the drugs were abused in the racemic form. No abuse of 2-CMC was detected at the timepoint of sample collection.

Prevalence and Genetic Characterization of Porcine Respiratory Coronavirus in Korean Pig Farms.

Porcine respiratory coronavirus (PRCV) is a member of the species Alphacoronavirus 1 within the genus Alphacoronavirus of the family Coronaviridae. A few studies have been conducted on the prevalence of PRCV since its first identification in 1997, but there have been no recent studies on the prevalence and genetic characterization of the virus in Korea. In this study, the seroprevalence of PRCV was determined in Korean pig farms using a commercially available TGEV/PRCV differential enzyme-linked immunosorbent assay kit. The farm-level seroprevalence of PRCV was determined to be 68.6% (48/70), similar to previous reports in Korea, suggesting that PRCV is still circulating in Korean pig herds nationwide. Among the 20 PRCV-seropositive farms tested in this study, PRCV RNAs were detected in 17 oral fluid samples (28.3%) from nine farms (45.0%), while TGEV RNAs were not detected in any sample. To investigate the genetic characteristics of Korean PRCV strains, genetic and phylogenetic analyses were conducted on PRCV spike gene sequences obtained in this study. The three Korean PRCV strains (KPRCV2401, KPRCV2402, and KPRCV2403) shared 98.5-100% homology with each other and 96.2-96.6% and 91.6-94.5% homology with European and American strains, respectively. A 224-amino acid deletion was found in the S gene of both Korean and European PRCVs but not in that of American PRCVs, suggesting a European origin for Korean PRCVs. Phylogenetic analysis showed that Korean PRCVs are more closely related to European PRCVs than American PRCVs but clustered apart from both, suggesting that Korean PRCV has evolved independently since its emergence in Korean PRCVs. The results of this study will help expand knowledge on the epidemiology and molecular biology of PRCV currently circulating in Korea.

Label-Free Detection of African Swine Fever and Classical Swine Fever in the Point-of-Care Setting Using Photonic Integrated Circuits Integrated in a Microfluidic Device.

Swine viral diseases have the capacity to cause significant losses and affect the sector's sustainability, a situation further exacerbated by the lack of antiviral drugs and the limited availability of effective vaccines. In this context, a novel point-of-care (POC) diagnostic device incorporating photonic integrated circuits (PICs), microfluidics and information, and communication technology into a single platform was developed for the field diagnosis of African swine fever (ASF) and classical swine fever (CSF). The device targets viral particles and has been validated using oral fluid and serum samples. Sensitivity, specificity, accuracy, precision, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated to assess the performance of the device, and PCR was the reference method employed. Its sensitivities were 80.97% and 79%, specificities were 88.46% and 79.07%, and DOR values were 32.25 and 14.21 for ASF and CSF, respectively. The proposed POC device and PIC sensors can be employed for the pen-side detection of ASF and CSF, thus introducing novel technological advancements in the field of animal diagnostics. The need for proper validation studies of POC devices is highlighted to optimize animal biosecurity.