Search

Bovine respiratory disease complex (BRDC) represents a global acute respiratory condition that imposes substantial economic burdens on the cattle industry due to its high morbidity and mortality rates. Various factors contribute to the development of BRDC, including pathogen infections, environmental stresses, weaning of calves, and herd relocation. Viral pathogens, notably bovine respiratory syncytial virus (BRSV) and bovine viral diarrhea virus (BVDV), play a critical role in the etiology of BRDC, with single or combined viral infections being particularly clinically significant. In this study, we developed a duplex TaqMan-based real-time RT-PCR assay targeting the conserved regions of the F gene of BRSV and the 5′ UTR sequence of BVDV. The limits of detection for BRSV and BVDV were 6.83 copies/μL and 5.24 copies/μL, respectively. Our validation data suggest the assay has excellent sensitivity, specificity and reproducibility. Testing of clinical samples revealed prevalence of BRSV and BVDV in local farms in Jiangsu Province, China. This study provides an efficient diagnostic tool for the epidemiological investigation of BRDC. [ABSTRACT FROM AUTHOR]

Three species of cecidomyiid midges (Diptera: Cecidomyiidae) cause significant yield losses on wheat in Europe: Sitodiplosis mosellana (Géhin), Contarinia tritici (Kirby) and Haplodiplosis marginata (von Roser). Eggs and young larvae may be parasitised by a complex of hymenopteran parasitoids belonging to the Pteromalidae and Platygastridae families which contributes to natural pest control. We have developed molecular tools for detecting and identifying seven parasitoid species previously encountered in Belgium inside individual wheat midge larvae. Barcode DNA sequences from COI, 18S and 28S genes were obtained from the midges and parasitoid species. Each of the three genes allowed all the species to be distinguished although 18S was the only one displaying a barcoding gap, both between parasitoids and midges, and at the species level. Based on the 18S gene, we developed a TaqMan assay to assess parasitism in midge larvae, regardless of the midge and parasitoid species. Next, two group-specific PCR primer pairs were generated, allowing the separate amplification of midge DNA or parasitoid DNA in parasitised individuals and subsequent identification by Sanger sequencing. Finally, species-specific primers were designed to identify six parasitoid species by simple PCR amplification. These tools were successfully applied to assess the parasitism rate of S. mosellana larvae in seven Belgian fields. [ABSTRACT FROM AUTHOR]

Background: Melon (Cucumis melo L.), an important cucurbit crop, faces production limitations due to powdery mildew (PM). Developing resistant varieties offers a sustainable, genetics-based alternative to chemical treatments. Therefore, identifying PM resistance quantitative trait loci (QTL) and creating trait-associated markers are essential for efficient melon PM resistance improvement through marker-assisted backcrossing (MABC). Results: Three F2 populations, A6, B2, and C4, were generated for QTL mapping of PM resistance. Major QTL were identified on chromosome 2 in A6, chromosome 5 in B2, and chromosomes 5 and 12 in C4. A series of TaqMan® assays targeting regions on chromosomes 2, 5, and 12 were developed and validated for foreground and recombinant selection, complemented by the double digest restriction-site associated DNA genotyping system to evaluate the recurrent parent genome recovery. Three MABC programs using resistant donor parents from A6 and C4 crossed with elite susceptible recurrent parents with green and orange fruit flesh were implemented. After two to three cycles of MABC, individual QTL was successfully introgressed into elite genetic backgrounds, giving six PM resistance lines in each green- and orange-fleshed background. PM inoculation on the twelve near-isogenic lines confirmed their resistance to PM. Conclusions: We have identified major PM resistance QTL for melon on chromosomes 2, 5, and 12 and have introgressed individual QTL to elite genetic backgrounds using MABC in three and a half years. This study demonstrates the power of combining high-throughput genotyping with breeding efforts and showcases the efficiency of molecular breeding. [ABSTRACT FROM AUTHOR]

Cervical cancer (CC) has been the prominent cause of cancer-associated fatalities among women in developing countries. In terms of occurrence and mortality, it is ranked second in Bangladesh. Although different genetic polymorphisms linked with this cancer have been investigated over time, the association between the HOTAIR rs7958904 variant and cervical cancer is being reported for the first time in Bangladeshi women. RT-PCR-based TaqMan assay was employed to perform this case–control study on 200 cervical cancer patients and 148 healthy volunteers. Both cases and controls had average ages of 57.5 and 52.5 years, respectively. According to Hardy–Weinberg equilibrium, the rs7958904 allele of HOTAIR gene pretended no deviation for both cases and control groups. The genotyping results showed that rs7958904 has a significant correlation to the development of cervical cancer in different genetic association models, such as co-dominant 1 (CC vs. GG: OR = 1.67, p = 0.0435), co-dominant 2 (CC vs. GG: OR = 3.13, p = 0.0006), co-dominant 3 (CC vs. CG: OR = 1.88, p = 0.0384), dominant (CG + CC vs. GG: OR = 1.98, p = 0.004), recessive (CC vs. GG + CG: OR = 2.25, p = 0.005), and allele model (C vs. G: OR = 1.70, p = 0.0006). In conclusion, the HOTAIR rs7958904 variant has a substantial role in cervical cancer development in Bangladeshi women. Further functional studies with a larger population size are required to support our findings. [ABSTRACT FROM AUTHOR]

Abstract Three species of cecidomyiid midges (Diptera: Cecidomyiidae) cause significant yield losses on wheat in Europe: Sitodiplosis mosellana (Géhin), Contarinia tritici (Kirby) and Haplodiplosis marginata (von Roser). Eggs and young larvae may be parasitised by a complex of hymenopteran parasitoids belonging to the Pteromalidae and Platygastridae families which contributes to natural pest control. We have developed molecular tools for detecting and identifying seven parasitoid species previously encountered in Belgium inside individual wheat midge larvae. Barcode DNA sequences from COI, 18S and 28S genes were obtained from the midges and parasitoid species. Each of the three genes allowed all the species to be distinguished although 18S was the only one displaying a barcoding gap, both between parasitoids and midges, and at the species level. Based on the 18S gene, we developed a TaqMan assay to assess parasitism in midge larvae, regardless of the midge and parasitoid species. Next, two group-specific PCR primer pairs were generated, allowing the separate amplification of midge DNA or parasitoid DNA in parasitised individuals and subsequent identification by Sanger sequencing. Finally, species-specific primers were designed to identify six parasitoid species by simple PCR amplification. These tools were successfully applied to assess the parasitism rate of S. mosellana larvae in seven Belgian fields.

Duck adeno-associated Virus (DAAV) is a novel pathogen that was recently discovered in ducks. To establish a molecular detection assay for DAAV for further epidemiological investigation and pathogenic mechanism. Here, we designed specific primers and probes according to the sequence characteristics of the newly discovered DAAV and then established a TaqMan real-time PCR method (TaqMan-qPCR) for the detection of DAAV. Our data showed that the established TaqMan-qPCR for detecting DAAV had high sensitivity, with the lowest detection limit of 29.1 copies/μL. No cross reaction was found with duck circovirus (DuCV), H9N2 subtype avian influenza virus (AIV), avian Tembusu virus (ATmV). duck hepatitis A virus 1 and 3 (DHAV-1 and DHAV-3), duck adenovirus A (DAdV-A), duck adenovirus 3 (DAdV-3), or duck enteritis virus (DEV). The repeatability was excellent, with the coefficients of variation of repeated intragroup and intergroup tests ranging from 0.12–0.21% and 0.62–1.42%, respectively. Seventy-eight clinical samples collected from diseased or deceased ducklings were tested. The results showed that the DAAV positive rate was 21.79%, and a triple infection (DAAV+MDPV+GPV) was found. These data provide technical support for further molecular epidemiological surveillance and pathogenic mechanism studies of DAAV infection.

Bovine respiratory disease complex (BRDC) represents a global acute respiratory condition that imposes substantial economic burdens on the cattle industry due to its high morbidity and mortality rates. Various factors contribute to the development of BRDC, including pathogen infections, environmental stresses, weaning of calves, and herd relocation. Viral pathogens, notably bovine respiratory syncytial virus (BRSV) and bovine viral diarrhea virus (BVDV), play a critical role in the etiology of BRDC, with single or combined viral infections being particularly clinically significant. In this study, we developed a duplex TaqMan-based real-time RT-PCR assay targeting the conserved regions of the F gene of BRSV and the 5′ UTR sequence of BVDV. The limits of detection for BRSV and BVDV were 6.83 copies/μL and 5.24 copies/μL, respectively. Our validation data suggest the assay has excellent sensitivity, specificity and reproducibility. Testing of clinical samples revealed prevalence of BRSV and BVDV in local farms in Jiangsu Province, China. This study provides an efficient diagnostic tool for the epidemiological investigation of BRDC.

Meat adulteration and admixing are prevalent malpractices observed in processed and raw meat samples, where the consumption of adulterated meat has been associated with food allergies, financial losses, and consumer distrust. Meat authentication is pivotal to address these concerns. The meat authenticity can be determined through genetic, protein, and immunological markers and advanced detection methods. However, these methods often target a single species and lack the specificity to distinguish closely related species. Here, in the present study, we have developed a multiplex detection method based on the species-specific primers and probes, that can target four meat species in one reaction. The developed method amplifies the mitochondrial genomic regions of chicken, pork, sheep and goat using TaqMan multiplex probe-based RT-qPCR assay. Unique pairs of species-specific primers and probes that target specific mitochondrial DNA (mtDNA) regions of each species were designed and screened for specificity and sensitivity. The detection limit for species identification using the designed primers in real-time qPCR assays was 0.1 picogram per microliter (pg/μL) DNA detected in singleplex reaction and facilitates the simultaneous detection of closely related species, such as goat and sheep. Further, DNA-based probes were utilized in a multiplex real-time qPCR assay to identify chicken, pork, sheep and goat DNA in a single tube reaction. The multiplex assay was validated for raw and processed meat products, demonstrating its applications in ensuring the quality of meat products and safeguarding consumer interests.

Dairy cattle breeding is aimed at improving the productivity, mainly through the use of a limited number of breeding bulls. As a result, an increase in inbreeding is observed causing accumulation of heterozygotes-carriers of recessive lethal mutations. A rise in the number of carriers reduces the profitability of dairy farms, since the frequency of embryonic and post-embryonic mortality increases, and the fertility of cows decreases. This paper presents the results of the development of test systems for rapid and inexpensive diagnostics of genetically determined cattle diseases that are significant for animal husbandry, namely for Holstein haplotypes 3, 6 and 7. The diagnostic technology is real-time PCR using TaqMan probes. Carriers of the Holstein haplotype 3 were not found in any of the studied populations. The carrier frequencies for HH6 and HH7 were 0.95 and 1.92%, respectively. Carrier frequencies are consistent with the results of studies worldwide, however, it is worth noting that only few large-scale screening studies have been carried out, since causative loci have been mapped relatively recently. [ABSTRACT FROM AUTHOR]

Background: The quantification of hepatitis B virus (HBV) DNA is used to monitor antiviral treatment for HBV infection. Recently, an HBV-DNA quantification reagent and assay protocol have been developed for the μTASWako g1 (Fujifilm Wako Pure Chemical Corporation, Osaka, Japan), a fully automated genetic analyzer that uses PCR-capillary electrophoresis. We evaluated the performance of the newly developed μTASWako HBVDNA assay using standard and clinical samples. Methods: The performance of μTASWako HBV-DNA was evaluated using 3rd World Health Organization International Standard for HBV. Thereafter, we evaluated the correlation between the serum HBV DNA concentrations obtained using the μTASWako HBV-DNA and the Roche Cobas AmpliPrep/COBAS TaqMan HBV test, version 2.0 (CAP/CTM HBV test v.2.0) using 190 serum samples from possible HBV carriers. Results: The limit of detection of the μTASWako HBV-DNA was 7.1 IU/mL and that of the CAP/CTM HBV test v.2.0 was 14.6 IU/mL. Seventy-six of the 190 samples yielded values between 1.3 - 7.8 log IU/mL from both assays. The correlation between the results of the assays for these samples was good, with a Deming regression equation of y = 0.929x + 0.041, 95% confidence intervals (CI) for the slope and intercept of 0.892 - 1.12 and -0.474 - 0.110, respectively, and a correlation coefficient r = 0.924. In the low concentration range of 1.3 - 4.0 log IU/mL (n = 64), the Deming regression equation was y = 0.893x + 0.126, and the 95% CIs for the slope and intercept were 0.915 - 1.342 and -0.930 - 0.025, respectively, and r = 0.809. There was also a close correlation for HBV DNA genotype C (n = 41), with a Deming regression equation of y = 0.975x - 0.048, 95% CIs of the slope and intercept of 0.872 - 1.183 and -0.591 - 0.188, respectively, and r = 0.950. The correlations of the four HBV DNA level categories (not detected, < LLOQ (< 1.3 log IU/mL), 1.3 - 3.2 log IU/mL, and ≥ 3.3 log IU/mL) between the two assays for the 190 samples was also compared, and the overall concordance rate was 81.6% (155/190), with a κ statistic of 0.73 (standard error, 0.040; 95% CI, 0.647 - 0.803). Conclusions: The μTASWako HBV-DNA has a performance comparable with that of the CAP/CTM HBV test, v.2.0. Thus, μTASWako HBV-DNA is useful for the monitoring of HBV infection. [ABSTRACT FROM AUTHOR]

The initial colonization of the intestine represents one of the most profound immunological exposures faced by the newborn. During the first three years of life, the intestinal microbial composition undergoes significant changes. At birth, the digestive tract is rapidly colonized by microorganisms of maternal and environmental origins. Microbiota's composition is influenced by various factors, including the mode of delivery, gestational age, type of feeding, and medication use. Through the current study, we specifically focused on elucidating the dynamics of gut microbiota colonization within the first three weeks of life of infants, shedding light on this critical phase of development.A prospective cohort study involving 29 preterm infants was conducted from January to September 2021 at the National Reference Center for Neonatology and Nutrition, in collaboration with the research laboratory of Children's Hospital at the University Hospital Center Ibn Sina in Rabat. Stool samples were collected from each infant's diapers into a sterile tube and send for laboratory analysis.A total of 203 stool samples were collected. For each newborn, one stool sample was obtained within the first 48 h after birth, followed by two samples per week over a period of three weeks. The microbial compositions of these samples were analyzed using real-time polymerase chain reaction.

ABSTRACT Human-infecting Cyclospora spp. currently include three coccidian parasites that cause the gastrointestinal disease cyclosporiasis in humans. They are often spread through contaminated produce, including leafy greens and berries. The increased availability of sensitive molecular tests for the diagnosis of cyclosporiasis is an important advancement, allowing public health agencies to better understand the scope and source of cyclosporiasis outbreaks. To improve the diagnosis of infected patients, rapidly detect outbreaks, and keep the food supply safe, it is important to continue to develop sensitive, reliable, and inexpensive tests to detect human-infecting Cyclospora spp. In this report, we describe the development and evaluation of two novel one-tube nested qPCR assays for the detection of human-infecting Cyclospora spp. in clinical stool samples, one targeting cytb and the other targeting coxI. Of these, the assay targeting the cytb mitochondrial locus possessed strong performance characteristics compared to a routinely used 18S assay, including a markedly improved (approximately 10-fold lower) relative detection limit of 0.613 oocysts per gram of feces. This is compared to coxI that has a relative detection limit equal to that of the 18S assay. Given the strong performance characteristics of the cytb assay, we propose that it may be useful to diagnostic laboratories wishing to screen clinical fecal specimens suspected of containing human-infecting Cyclospora spp. IMPORTANCE Human-infecting Cyclospora spp. cause gastrointestinal distress among healthy individuals contributing to morbidity and putting stress on the economics of countries and companies in the form of produce recalls. Accessible and easy-to-use diagnostic tools available to a wide variety of laboratories would aid in the early detection of possible outbreaks of cyclosporiasis. This, in turn, will assist in the timely traceback investigation to the suspected source of an outbreak by informing the smallest possible recall and protecting consumers from contaminated produce. This manuscript describes two novel detection methods with improved performance for the causative agents of cyclosporiasis when compared to the currently used 18S assay.

Simple Summary: Rapid diagnostic tools are critical for the management and eradication of boll weevil, Anthonomus grandis grandis. Here, we present the development and validation of a novel qPCR assay that enables same-day identification of Anthonomus grandis subspecies. Rapid and accurate identification of Anthonomus grandis subspecies is crucial for effective management and eradication. Current diagnostic methods have limitations in terms of time to diagnosis (up to seven days) and can yield ambiguous results. Here, we present the validation of a custom TaqMan SNP Genotyping Assay for the rapid and accurate identification of A. grandis grandis (boll weevil) and A. g. thurberiae (thurberia weevil) subspecies. To validate the assay, we conducted three main experiments: (1) a sensitivity test to determine the DNA concentration range at which the assay performs, (2) a non-target specificity test to ensure no amplification in non-target weevils (false positives), and (3) an accuracy test comparing the results of the new assay to previously established methods. These experiments were carried out in parallel at three independent facilities to confirm the robustness of the assay to variations in equipment and personnel. We used DNA samples from various sources, including field-collected specimens, museum specimens, and previously isolated DNA. The assay demonstrated high sensitivity (PCR success with ≥0.05 ng/µL DNA template), specificity (0.02 false positive rate), and accuracy (97.7%) in diagnosing boll weevil and thurberia weevil subspecies. The entire workflow, including DNA extraction, assay preparation, PCR run time, and data analysis, can be completed within a single workday (7–9 h) by a single technician. The deployment of this assay as a diagnostic tool could benefit boll weevil management and eradication programs by enabling same-day diagnosis of trap-captured or intercepted weevil specimens. Furthermore, it offers a more reliable method for identifying unknown specimens, contributing to the overall effectiveness of boll weevil research and control efforts. [ABSTRACT FROM AUTHOR]

Background: The significance of HTLV-1 proviral load as a prognostic biomarker in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) has been a subject of controversy. This study aims to assess the impact of HTLV-1 proviral load (PVL) on the clinical outcome in patients with HAM/TSP. Methods: An absolute quantitative HTLV-1 PVL RT-qPCR, TaqMan method was developed with 100% sensitivity and specificity. Then, from 2005-2018, the HTLV-1 PVL of 90 eligible newly diagnosed HAM/TSP patients were assessed for demographic, clinical symptoms and their associations with HTLV-1-PVL. Results: The quality control of the designed RT-qPCR showed a sensitivity and specificity of 100%. Spasticity in lower limbs in 58.9% and urinary symptoms in 17.8% of HAM/TSPs were observed. Using this designed RT-qPCR, the HTLV-1-PVL strongly affected spasticity and sphincter disturbance (p=0.05). The multivariate logistic test showed that only the beginning of lower limb weakness along with tremor was associated with PVL (OR: 2.78. 95% CI (0.99-1.02) and p=0.05). Urinary incontinence was prevalent among these patients; however, no association was identified with the HTLV-1 proviral load (PVL). Conclusion: The absolute RT-qPCR developed for measuring HTLV-1 proviral load (PVL) demonstrated reliable results. Despite a high prevalence of urinary incontinence in these patients, no association was observed with the PVL. Consequently, it appears that HTLV-1 proviral load is specifically associated with developing spasticity in HAM/TSP. [ABSTRACT FROM AUTHOR]

The tropical sea cucumber Holothuria scabra is naturally found in the Indo-West Pacific. However, due to their commercial value, natural H. scabra populations have declined significantly in recent years, resulting in its status as an endangered species. Surveys of H. scabra resource pose a challenge due to its specific characteristics, such as sand-burrowing behavior. To overcome this problem, our study established a convenient and feasible method for assessing H. scabra resources using environmental DNA (eDNA) monitoring technology. First, H. scabra-specific TaqMan primers and probe were designed based on its cox1 gene, followed by the development of an eDNA monitoring method for H. scabra in two separate sea areas (Xuwen and Daya Bay). The method was subsequently employed to investigate the distribution of H. scabra and assess the effects of aquaculture stock enhancement through juvenile releasing in the Weizhou Island sea area. The H. scabra eDNA monitoring approach was found to be more appropriate and credible than traditional methods, and a positive impact of stocking on H. scabra populations was observed. In summary, this is the first report to quantify eDNA concentration in a Holothuroidea species, and it provides a convenient and accurate method for surveying H. scabra resources. This study introduces novel concepts for eDNA-based detection of endangered marine benthic animals and monitoring their population distribution and abundance. [ABSTRACT FROM AUTHOR]

To develop a fast and convenient method for the molecular identification of donkey meat products, this study selected donkey meat and duck meat (a common meat used for adulteration) as the research objects, screened specific primers and TaqMan probes, and conducted sensitivity and specificity experiments with a portable Mini8 Plus real-time fluorescence quantitative PCR instrument. By drawing the amplification standard curve and determining the mass/DNA ratio constants of donkey meat and duck meat, it detected the real donkey meat samples and the simulated samples adulterated with different proportions of duck meat (20%, 40%, 60%, and 80%, respectively). The results showed that the method had good specificity for both donkey meat and duck meat, which could be clearly distinguished from meat from horses, pigs, goats, sika deer, cattle, chickens, and dogs. The detection limit of donkey-derived DNA components was 0.01 ng/μL, and that of duck-derived DNA components was 0.1 ng/μL. Its sensitivity to duck meat components in the mixture of donkey meat and duck meat was 0.1% (w/w). The established standard curve showed a sound linear relationship. The amplification standard curve of donkey DNA was: y=−3.584x+27.003, R2=0.9982. The amplification standard curve of duck DNA was: y=−3.538x+30.907, R2=0.9991. A market pilot survey was conducted on 35 donkey meat samples using the established method, and revealed that 6 donkey meat samples (17.1%) contained duck meat. These results indicated that the real-time PCR method could be used for the rapid and accurate detection of other meat (such as duck meat) adulterated in donkey meat products. The combination of a simple detection procedure with a portable real-time PCR system provides technical support for food adulteration monitoring and control at the retail or market level.

Abstract Background The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI. Methods A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21–28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI. Discussion The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 h and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific prevalent pathogens as a cause of acute illness. Study Registration Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú.

Contagious bovine mastitis caused by Mycoplasma bovis and other Mycoplasma species including Mycoplasma californicum, Mycoplasma bovigenitalium, Mycoplasma alkalescens, Mycoplasma arginini, and Mycoplasma canadense is an economical obstacle affecting many dairy herds throughout California and elsewhere. Routine bacteriological culture-based assays for the pathogens are slow and subject to false-positive results due to the presence of the related, non-pathogenic species Acholeplasma laidlawii. To address the need for rapid and accurate detection methods, a new TaqMan multiplex, quantitative real-time PCR (qPCR) assay was developed that targets the 16S rRNA gene of Mycoplasma, rpoB gene of M. bovis, and the 16S to 23S rRNA intergenic transcribed spacer (ITS) region of A. laidlawii. qPCR amplification efficiency and range of detection were similar for individual assays in multiplex as when performed separately. The multiplex assay was able to distinguish between M. bovis and A. laidlawii as well as detect Mycoplasma spp. collectively, including Mycoplasma californicum, Mycoplasma bovigenitalium, Mycoplasma canadense, Mycoplasma arginini and Mycoplasma alkalescens. In milk, the lower limit of detection of M. bovis, M. californicum, and A. laidlawii with the multiplex assay was between 120 to 250 colony forming units (CFU) per mL. The assay was also able to simultaneously detect both M. bovis and A. laidlawii in milk when present in moderate (103 to 104 CFU/mL) to high (106 to 107 CFU/mL) quantities. Compared to laboratory culture-based methods, the multiplex qPCR diagnostic specificity (Sp) was 100% (95% CI [86.8-100]; n = 26) and diagnostic sensitivity (Se) was 92.3% (95% CI [74.9-99.1]; n = 26) for Mycoplasma species in milk samples collected from California dairy farms. Similarly, the Sp was 100% (95% CI [90.5-100]; n = 37) and Se was 93.3% (95% CI [68.1-99.8]; n = 15) for M. bovis. Our assay can detect and distinguish among M. bovis, other prevalent Mycoplasma spp., and non-pathogenic Acholeplasma laidlawii for effective identification and control of mycoplasma mastitis, ultimately supporting dairy cattle health and high-quality dairy products in California.

P. brasiliense is an important bacterial pathogen causing blackleg (BL) in potatoes. Nevertheless, P. brasiliense is often detected in seed lots that do not develop any of the typical blackleg symptoms in the potato crop when planted. Field bioassays identified that P. brasiliense strains can be categorized into two distinct classes, some able to cause blackleg symptoms and some unable to do it. A comparative pangenomic approach was performed on 116 P. brasiliense strains, of which 15 were characterized as BL-causing strains and 25 as non-causative. In a genetically homogeneous clade comprising all BL-causing P. brasiliense strains, two genes only present in the BL-causing strains were identified, one encoding a predicted lysozyme inhibitor Lprl (LZI) and one encoding a putative Toll/interleukin-1 receptor (TIR) domain-containing protein. TaqMan assays for the specific detection of BL-causing P. brasiliense were developed and integrated with the previously developed generic P. brasiliense assay into a triplex TaqMan assay. This simultaneous detection makes the scoring more efficient as only a single tube is needed, and it is more robust as BL-causing strains of P. brasiliense should be positive for all three assays. Individual P. brasiliense strains were found to be either positive for all three assays or only for the P. brasiliense assay. In potato samples, the mixed presence of BL-causing and not BL-causing P. brasiliense strains was observed as shown by the difference in Ct value of the TaqMan assays. However, upon extension of the number of strains, it became clear that in recent years additional BL-causing lineages of P. brasiliense were detected for which additional assays must be developed. [ABSTRACT FROM AUTHOR]

Puja Neopane, Jerome Nypaver, Rojeet Shrestha, Safedin Beqaj Patients Choice Laboratories, Indianapolis, IN, 46278, USACorrespondence: Safedin Beqaj, Patients Choice Laboratories, 7026 Corporate Dr, Indianapolis, IN, 46278, USA, Email sajo@pclabsindiana.comPurpose: To detect and differentiate co-infection with influenza and respiratory syncytial virus during the COVID pandemic, a rapid method that can detect multiple pathogens in a single test is a significant diagnostic advance to analyze the outcomes and clinical implications of co-infection. Therefore, we validated and evaluated the performance characteristics of TaqMan SARS-CoV-2, Flu A/B, RSV RT-PCR multiplex assay for the detection of SARS-CoV-2, Flu A/B, and RSV using nasopharyngeal and saliva samples.Materials and Methods: The method validation was performed by using culture fluids of Influenza A virus (H3N2) (A/Wisconsin/67/2005), Influenza B virus (B/Virginia/ATCC4/2009), RSV A2 cpts-248, SARS-CoV-2 (USA-WA1/2020) and quantitative RNA controls of Influenza A virus (H1N1) strain A/PR/8/34 (VR-95DQ), RSV A2 (VR-1540DQ) and SARS-CoV-2 (MN908947.3 Wuhan-Hu-1) from ATCC and Zeptometrix, NY, USA. A total of 110 nasopharyngeal specimens and 70 saliva samples were used for the SARS-CoV-2 detection, and a total of 70 nasopharyngeal specimens were used for Influenza and RSV detection. Total RNA was extracted from all the samples and multiplex PCR was performed using TaqMan SARS-CoV-2, Flu A/B, RSV RT-PCR multiplex assay. The assay was used for SARS-CoV-2 variant (B.1.1.7_601443, B.1.617.1_1662307, P.1_792683, B.1.351_678597, B.1.1.529/BA.1).Results: Validation controls showed accurate and precise results. The correlation study found the accuracy of 96.38 to 100% (95% CI) in nasopharyngeal and 94.87 to 100% (95% CI) in saliva for SARS-CoV-2 and 91.1 to 100% (95% CI) for both Influenza A/B and RSV. The diagnostic efficiency of this assay was not affected by SARS-CoV-2 variant, including Omicron.Conclusion: The TaqMan SARS-CoV-2, Flu A/B, RSV RT-PCR multiplex assay is a rapid method to detect and differentiate SAR-CoV-2, Flu A and B, and RSV in nasopharyngeal and saliva samples. It has a significant role in the diagnosis and management of respiratory illnesses and the clinical implications of co-infection.Keywords: TaqMan, SARS-CoV-2, Flu A/B, respiratory syncytial virus, RSV, multiplex

Background: The study of the etiology of acute febrile illness (AFI) has historically been designed as a prevalence of pathogens detected from a case series. This strategy has an inherent unrealistic assumption that all pathogen detection allows for causal attribution, despite known asymptomatic carriage of the principal causes of acute febrile illness in most low- and middle-income countries (LMICs). We designed a semi-quantitative PCR in a modular format to detect bloodborne agents of acute febrile illness that encompassed common etiologies of AFI in the region, etiologies of recent epidemics, etiologies that require an immediate public health response and additional pathogens of unknown endemicity. We then designed a study that would delineate background levels of transmission in the community in the absence of symptoms to provide corrected estimates of attribution for the principal determinants of AFI. Methods: A case-control study of acute febrile illness in patients ten years or older seeking health care in Iquitos, Loreto, Peru, was planned. Upon enrollment, we will obtain blood, saliva, and mid-turbinate nasal swabs at enrollment with a follow-up visit on day 21–28 following enrollment to attain vital status and convalescent saliva and blood samples, as well as a questionnaire including clinical, socio-demographic, occupational, travel, and animal contact information for each participant. Whole blood samples are to be simultaneously tested for 32 pathogens using TaqMan array cards. Mid-turbinate samples will be tested for SARS-CoV-2, Influenza A and Influenza B. Conditional logistic regression models will be fitted treating case/control status as the outcome and with pathogen-specific sample positivity as predictors to attain estimates of attributable pathogen fractions for AFI. Discussion: The modular PCR platforms will allow for reporting of all primary results of respiratory samples within 72 h and blood samples within one week, allowing for results to influence local medical practice and enable timely public health responses. The inclusion of controls will allow for a more accurate estimate of the importance of specific prevalent pathogens as a cause of acute illness. Study Registration: Project 1791, Registro de Proyectos de Investigación en Salud Pública (PRISA), Instituto Nacional de Salud, Perú. [ABSTRACT FROM AUTHOR]

The mixed infection of duck Tembusu virus (DTMUV) and goose astrovirus (GoAstV) is an important problem that endangers the goose industry. Although quantitative PCR has been widely used in monitoring these two viruses, there is no reliable method to detect them at the same time. In this study, by analyzing the published genomes of DTMUV and goose astrovirus genotype 2 (GoAstV-2) isolated in China, we found that both viruses have high conservation, showing 96.5 to 99.5% identities within different strains of DTMUV and GoAstV, respectively. Subsequently, PCR primers and TaqMan probes were designed to identify DTMUV and GoAstV-2, and different fluorescent reporters were given to two probes for differential diagnosis. Through the optimization and verification, this study finally developed a duplex TaqMan qPCR method that can simultaneously detect the above two viruses. The lower limits of detection were 100 copies/µL and 10 copies/µL for DTMUV and GoAstV-2 under optimal condition. The assay was also highly specific in detecting one or two viruses in various combinations in specimens, and provide tool for clinical diagnosis of mixed infections of viruses in goose. [ABSTRACT FROM AUTHOR]

Coronary heart disease (CHD) is the most prevalent cause of cardiovascular mortality in the world. It is well established that microRNAs (miRNAs) and their variants have an essential role in regulating the development of cardiovascular physiology, thus impacting the pathophysiology of heart diseases. This study was designed to determine the possible association of miRNA polymorphisms (miRNA‐146a rs2910164C/G and miR‐4513 rs2168518G/A) with susceptibility to CHD in Egyptian patients and their correlation with different biochemical parameters. The study comprised 300 participants, including 200 unrelated patients with CHD and 100 healthy controls. Anthropometric and blood biochemical parameters were measured as well genetic analysis for rs2910164C/G and rs2168518G/A polymorphisms were performed for all subjects using TaqMan real‐time PCR assay. Our results revealed that the biomedical parameters have a significant correlation between CHD patients and healthy controls with a p < 0.05. Analyses of genotype distribution for (rs2910164 and rs2168518) revealed a significant association with CHD [odd ratio = 4.54, confidence interval (CI 95%) = (2.41–8.53)] and [odd ratio = 0.88, (CI 95%) = (0.83–0.92)], respectively. Furthermore, a statistically significant difference was detected between lipid profile levels and both rs2910164 and rs2168518 polymorphisms. The present study's findings indicated that the selected polymorphisms, miR‐146a rs2910164 and miR‐4513 rs2168518 could represent a useful biomarker for susceptibility to CHD in the Egyptian population. These genetic characteristics and personal habits and environmental factors may contribute to the development of CHD. [ABSTRACT FROM AUTHOR]

ABSTRACT: The epidemic of goose astrovirus (GoAstV) caused huge losses to the poultry industry. Epidemiological studies in China revealed 2 circulating genotypes of GoAstV, but there is a lack of differential diagnosis tools. By analyzing all published genomes of GoAstV, this study designed specific PCR primers and Taqman probes to recognize different genotypes of GoAstV. After optimization and verification, this study developed a Taqman-based real-time quantitative PCR method that is capable of differential diagnosis. The established qPCR exhibited detection limitations of 100 copies/μL or 10 copies/μL, respectively, for GoAstV genotype 1 and genotype 2, and showed no false positive for other common avian viruses. This method was then used to analyze 72 samples collected from different regions in Jiangxi, and the results were verified by genome sequencing and phylogenetic analysis. These results revealed a complex coinfection of GoAstV different genotypes in China, highlighting the importance of long-term focus on the prevalence and genome evolution of GoAstV.

After entry of a quarantine/regulated pathogen, infected plants shall be destroyed, and the cultivated area (e.g., greenhouse) shall be disinfected. Therefore, the selection of an effective disinfectant plays an important role. With the availability of different methods for virus quantification, we investigated the application of quantitative ELISA (qELISA), RT-qPCR (reverse transcription-quantitative polymerase chain reaction), and bioassays for the quantification of disinfectant efficacy. Therefore, we estimated the titer reduction in tomato brown rugose fruit virus (ToBRFV), a regulated pathogen, in plant sap and on germ carriers after treatment with MENNO Florades 4% for 16 h. The virus load before and after the treatment was measured with the mentioned methods. The RT-qPCR and qELISA methods showed very low efficacy in the presence of the disinfectant. Although bioassays are time-consuming, need purified particles for establishing the quantification models, and are less sensitive than RT-qPCR, they were able to quantify the differences in virus titer in the presence/absence of disinfectant. Interestingly, the bioassays reached at least the lower limit sensitivity of a qELISA. By being less sensitive to the presence of the disinfectant, bioassays proved to be the only technique for the determination of the disinfectant efficacy against ToBRFV on different germ carriers as well as on virus-infected plant sap. [ABSTRACT FROM AUTHOR]

The canine distemper virus (CDV), which infects dogs and a broad range of animal species, remains a serious concern in Türkiye and across the world. The current study shows that CDV can be detected and isolated rapidly and specifically in naturally infected dogs. Whole blood, nasal swab, ocular swab, rectal swab, and urine samples from 50 stray dogs were used in the study (n = 250). The presence of the CDV genome was confirmed in 105 (42%) samples using one-Step real-time RT-PCR. In total, 39 dogs were diagnosed with CDV infection based on the detection of cytopathic effects in MDCK, which was verified by the fluorescent antibody technique. A total of 12 one-Step real-time RT-PCR negative samples, consisting of 4 rectal swabs and 8 urine samples, were found to be positive by virus isolation. Blood, nasal swab, ocular swab (P<0.01, r = 1), rectal swab (P<0.01, r = 0.844), and urine samples (P<0.01, r = 0.697) all showed positive correlations in the tests for viral genome detection and virus isolation. CPE levels of high 37 (31.62%), medium 26 (22.23%) and low 54 (46.15%) were detected in a total of 117 (46.8%) samples with viral growth in cell culture. The highest CPE levels detected by FAT were for rectal swab and urine samples. In conclusion, the one-step real-time RTPCR method on rectal swab samples proved to be a very sensitive method for the rapid and reliable CDV detection. Besides, non-modified MDCK can be used to isolate CDV from naturally infected dogs. [ABSTRACT FROM AUTHOR]

Two primer set/probe combinations targeting variable regions on the 23S rRNA gene were designed to detect and quantify chlamydiae in DNA extracted from brain swabs of the endangered Houston toad (Anaxyrus houstonensis) using SYBRGreen- and Taqman-based quantitative polymerase chain reaction (qPCR). Prevalence and abundance values for samples were generally different between SYBRGreen- and Taqman-based detection methods, with higher specificity observed for Taqman-based detection. Of the 314 samples analyzed, initial screening with SYBRGreen-based qPCR retrieved 138 positive samples, of which 52 were confirmed by Taqman-based analyses as chlamydiae. All of these samples were subsequently identified as Chlamydia pneumoniae by specific qPCR and confirmed by comparative sequence analyses of 23S rRNA gene amplicons. These results demonstrate the usefulness of our developed qPCR methods to screen for and verify prevalence of chlamydiae in DNA of brain swabs, and ultimately specifically identify and quantify chlamydiae, specifically C. pneumoniae in these samples. [ABSTRACT FROM AUTHOR]

The Siberian silk moth, Dendrolimus sibiricus Tschetverikov, is a very serious pest of conifers in Russia and is an emerging threat in North America where an accidental introduction could have devastating impacts on native forest resources. Other Dendrolimus Germar species and related Eurasian lasiocampids in the genus Malacosoma (Hubner) could also present a risk to North America's forests. Foreign vessels entering Canadian and U.S. ports are regularly inspected for Lymantria dispar (Linnaeus) and for the presence of other potentially invasive insects, including suspicious lasiocampid eggs. However, eggs are difficult to identify based on morphological features alone. Here, we report on the development of two TaqMan (Roche Molecular Systems, Inc. Rotkreuz, Switzerland) assays designed to assist regulatory agencies in their identification of these insects. Developed using the barcode region of the cytochrome c oxidase I (COI) gene and run in triplex format, the first assay can detect Dendrolimus and Malacosoma DNA, and can distinguish North American from Eurasian Malacosoma species. The second assay is based on markers identified within the internal transcribed spacer 2 (ITS2) region and was designed to specifically identify D. sibiricus , while discriminating closely related Dendrolimus taxa. In addition to providing direct species identification in the context of its use in North America, the D. sibiricus assay should prove useful for monitoring the spread of this pest in Eurasia, where its range overlaps with those of the morphologically identical D. superans (Butler) and similar D. pini (Linnaeus). The assays described here can be performed either in the lab on a benchtop instrument, or on-site using a portable machine. [ABSTRACT FROM AUTHOR]

In British Columbia (BC; Canada) Atlantic salmon (Salmo salar L.) production, Tenacibaculum members are associated with 'mouthrot' and disease identification is based on gross observation and clinical data. Genomic similarities (i.e., putative virulence factors) between T. ovolyticum and other better-characterized agents of mouthrot could imply potential pathogenicity. While T. ovolyticum has not been directly linked to salmon mortality events in BC, it has been isolated from diseased marine fish. To investigate T. ovolyticum's pathogenicity in situ, a T. ovolyticum 16S rDNA qPCR assay targeting a ~155 bp amplicon was developed. The assay was used to screen 67 biotic and 33 abiotic samples collected from a BC Atlantic salmon (Salmo salar L.) net-pen site before, during, and after a mouthrot outbreak. The assay was specific, quantifiable and detectable for T. ovolyticum over 6-log and 8-log units, respectively. However, cycle quotients differed between the BC isolate and type strain of T. ovolyticum, suggesting that qualitative use of the qPCR assay in field samples would be more accurate. Only two out of 100 samples were T. ovolyticum-positive, indicating limited involvement in this particular outbreak. However, the ecological role of T. ovolyticum and its involvement in the pathogenesis of other mouthrot outbreaks in Atlantic salmon is unknown. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa is a fastidious Gram-negative bacterium that is associated with several important plant diseases, and is regulated as a quarantine pest in many countries where strategies are implemented to prevent its introduction and spread. To enact efficient quarantine measures, effective and early detection of the pathogen are essential, especially because global trade of goods increases the risks of introduction of alien pathogens. this study aimed to adapt two qPCR-based diagnostic methods (SYBR Green and Probe based qPCR), already in use to detect X. fastidiosa, for use with a nanoplate based digital PCR assay. Detection of the pathogen using the two digital PCR assays (EvaGreen- and Probe-based) was similar to standard qPCR, giving 100% sensitivity, specificity, and accuracy, while providing accurate absolute quantification of the pathogen when using experimental samples that had low concentrations of host DNA. Using undiluted plant DNA added with low concentrations of X. fastidiosa, only the TaqMan method maintained satisfactory performance and quantification, and is therefore preferred. These results are a first step demonstrating the usefulness of nanoplate-based digital PCR for detection of plant pathogens, which allows greater throughput than qPCR, reducing the time and cost of diagnostic assays. [ABSTRACT FROM AUTHOR]

Information on the infection incidence of blackleg-causing soft rot Pectobacteriaceae (BL-SRP) in potato crops grown from minitubers (PB1-crop) and the distribution of BL-SRP in individual plants was collected during a two-year survey conducted at five potato growers located in the Netherlands. In the last weeks before haulm destruction, leaves, stems, and tubers of 100 or 200 plants were analyzed separately for the presence of Pectobacterium parmentieri, P. brasiliense, P. atrosepticum, and Dickeya spp. Extracted plant parts enriched for BL-SRP were analyzed with TaqMan assays specific for the detection of blackleg-causing BL-SRP. In 2019, low incidences of P. parmentieri (1–6%) in leaves were found at four growing sites. At one farm, reactions were detected in TaqMan assays for D. zeae and D. chrysanthemi in leaves. In 2020, the crops of two growers were largely free from BL-SRP. At one farm, a high infection incidence (21%) was found for D. fangzhongdai in tubers. The isolated pathogen was able to cause potato blackleg. At two other farms, high infection incidences in tubers were found with P. brasiliense (35–39%) and P. parmentieri (12–19%), whereas the incidence of P. brasiliense in leaves was also high (8%). In conclusion, high infection incidences with BL-SRP in potatoes can be found in a PB1 crop at the end of the growing season. Infections in individual plants were found either in tubers or in leaves. The potential sources of initial infection are discussed. [ABSTRACT FROM AUTHOR]

Rapid and accurate identification of Anthonomus grandis subspecies is crucial for effective management and eradication. Current diagnostic methods have limitations in terms of time to diagnosis (up to seven days) and can yield ambiguous results. Here, we present the validation of a custom TaqMan SNP Genotyping Assay for the rapid and accurate identification of A. grandis grandis (boll weevil) and A. g. thurberiae (thurberia weevil) subspecies. To validate the assay, we conducted three main experiments: (1) a sensitivity test to determine the DNA concentration range at which the assay performs, (2) a non-target specificity test to ensure no amplification in non-target weevils (false positives), and (3) an accuracy test comparing the results of the new assay to previously established methods. These experiments were carried out in parallel at three independent facilities to confirm the robustness of the assay to variations in equipment and personnel. We used DNA samples from various sources, including field-collected specimens, museum specimens, and previously isolated DNA. The assay demonstrated high sensitivity (PCR success with ≥0.05 ng/µL DNA template), specificity (0.02 false positive rate), and accuracy (97.7%) in diagnosing boll weevil and thurberia weevil subspecies. The entire workflow, including DNA extraction, assay preparation, PCR run time, and data analysis, can be completed within a single workday (7–9 h) by a single technician. The deployment of this assay as a diagnostic tool could benefit boll weevil management and eradication programs by enabling same-day diagnosis of trap-captured or intercepted weevil specimens. Furthermore, it offers a more reliable method for identifying unknown specimens, contributing to the overall effectiveness of boll weevil research and control efforts.

Introduction: The leucyl-cystinyl aminopeptidase gene rs4869317 single nucleotide polymorphism (SNP) is associated with multiple conditions; for example, patients with the rs4869317 TT genotype experiencing septic shock have increased plasma clearance of vasopressin versus AA or AT genotypes. The current aim was to assess the appropriateness of a TaqMan? SNP genotyping assay as a tool to identify the rs4869317 SNP in human samples, given its association with serious medical conditions. Methods: Genomic DNA was amplified using sequence-specific forward/reverse primers, and allelic discrimination was achieved using VIC?- or FAM?-labeled TaqMan probes. The Applied BiosystemsTM QuantStudioTM 12?K Flex Real-Time PCR System was used for SNP genotyping, and data were analyzed by the TaqMan Genotyper software. Results: Intra- and interassay precisions were established, with results consistent within and between genotyping assays and between instruments and operators. Assay robustness was established across a range of input DNA (11?56?ng). The assay was 100% accurate for discriminating between alleles of the rs4869317 SNP (30 samples) and was concordant with results from independently performed Sanger sequencing. The detection of leucyl-cystinyl aminopeptidase rs4869317 SNP using TaqMan genotyping methods was shown to be an appropriate, reliable, and rapid analytical tool for generating allelic calls. Conclusion: This assay is a valid tool for genotyping analyses in clinical trials and potential applications in precision medicine.

Background and Objective: Sexually infections transmitted by bacteria are one of thetherapeutic and social problemsworldwide. The Real-time PCR assay is one of the most sensitive diagnostic and screening methods for these infections. The purpose of this study wassimultaneous detection of Chlamydia trachomatis and Mycoplasma genitaliumusing the TaqMan duplex real-time polymerase chain reaction. Materials and Methods: In the present study, we used extracted DNA from women with vaginal infections available in the bank ofthe molecular and medicalresearch center, Arak University of Medical Sciences, Arak, Iran. The duplex real-time PCR was evaluated to detectChlamydia trachomatis and Mycoplasmagenitalium in 110 vaginal andendocervical samples. To validate the diagnostic performance of the designedmethod, the tests were compared with a commercial diagnostic kit. Results: The size of the ampliconsOmpA, 135 bp and MgPa, 145bp,indicated the accuracy of the primers designing procedures. The analysis of a panel of human STI revealed no cross-reactivity in the method. The diagnostic sensitivity and specificity of developedTaqMan duplex real-time PCR were 97% and 75%, respectively,compared to a commercial diagnostic kit. Conclusion: The results indicated that the used TaqMan duplex real-time PCR technique is specific and cost-effective and can be an excellent alternative to commercial kits for simultaneously detecting C. trachomatis and M. genitalium. Although the disadvantage of this method is its high cost, this disadvantage has significantly been resolved by the multiplex method.

Xylella fastidiosa is a fastidious Gram-negative bacterium that is associated with several important plant diseases, and is regulated as a quarantine pest in many countries where strategies are implemented to prevent its introduction and spread. To enact efficient quarantine measures, effective and early detection of the pathogen are essential, especially because global trade of goods increases the risks of introduction of alien pathogens. this study aimed to adapt two qPCR-based diagnostic methods (SYBR Green and Probe based qPCR), already in use to detect X. fastidiosa, for use with a nanoplate based digital PCR assay. Detection of the pathogen using the two digital PCR assays (EvaGreen- and Probe-based) was similar to standard qPCR, giving 100% sensitivity, specificity, and accuracy, while providing accurate absolute quantification of the pathogen when using experimental samples that had low concentrations of host DNA. Using undiluted plant DNA added with low concentrations of X. fastidiosa, only the TaqMan method maintained satisfactory performance and quantification, and is therefore preferred. These results are a first step demonstrating the usefulness of nanoplate-based digital PCR for detection of plant pathogens, which allows greater throughput than qPCR, reducing the time and cost of diagnostic assays.

The detection of adulteration in the production of milk and other dairy products is crucial for economic reasons and consumer protection. In this study, yoghurts were produced from mixed milk (cow and sheep) in different ratios, and the percentage of sheep and cow milk was determined using TaqMan real‐time polymerase chain reaction (PCR). 1% of cow milk was determined in the yoghurts and 0.01 ng of cow and sheep DNA was determined in sensitivity analyses. Therefore, TaqMan real‐time PCR can be considered as a sensitive and reliable method for detecting cow DNA in yoghurt produced from mixed milk. [ABSTRACT FROM AUTHOR]

Downy mildew-free hop plantlets and rhizomes are essential to limit the introduction of this destructive pathogen, Pseudoperonospora humuli, into hopyards. The objective of this research was to determine which DNA-based diagnostic tools are optimal for P. humuli detection in plant tissue. Quantitative real-time PCR (qPCR) assays with TaqMan probes for nuclear (cl25015.3el) and mitochondrial (orf59) DNA loci were developed and tested side by side. A recombinase polymerase amplification (RPA) assay was designed based on the orf359 DNA locus. The mitochondrial qPCR assay had a 10-fold lower limit of detection (100 fg of genomic DNA) and was 60% more effective in detecting P. humuli in asymptomatic stems than the nuclear-based assay. Both qPCR assays had linear standard curves (R² > 0.99) but lacked the quantitative precision to differentiate leaf infections beyond I day postinoculation. A wide range of Cq values (≥4.9) in standardized tests was observed among isolates, suggesting that the number of mitochondria and nuclear DNA targets can vary. The absence of P. humuli DNA in symptomatic rhizomes was explained, in part, by the detection of Phytophthora DNA. However, the Phytophthora-specific atp9-nad9 assay cross-reacted with P. humuli, leading to false positive amplification. Sensitivity in the RPA assay was reduced by crude plant DNA extract. Improvements to the objectivity of calling positive amplifications and determining the onset of amplification from RPA fluorescence data were realized by applying the first and second derivatives, respectively. The orf359 qPCR assay is specific and sensitive, making it well suited for P. humuli diagnostics in plant tissue. [ABSTRACT FROM AUTHOR]

Background: The extent to which infections with Ixodes ricinus-borne pathogens (TBPs), other than Borrelia burgdorferi s. l. and tick-borne encephalitis virus (TBEV), cause disease in humans remains unclear. One of the reasons is that adequate diagnostic modalities are lacking in routine or research settings. Methods: We evaluated the analytical specificity, sensitivity and robustness of qPCR assays for the detection of Anaplasma phagocytophilum, Neoehrlichia mikurensis, Spiroplasma ixodetis, several Babesia species and Spotted Fever Rickettsia species as well as Bartonella species in human samples. Results: The qPCRs were found to perform well, given the difficulties of dealing with microorganisms for which confirmed patient materials are scarce or non-existent, a hurdle that was partially overcome by using synthetic controls. Spiking blood samples with the tested microorganisms showed that the detection of the TBPs was not inhibited by the presence of blood. The acceptable sensitivity when multiplexing the different pathogens, the good inter-assay variability and the absence of cross-reactivity make them potentially suitable as human diagnostics. Conclusions: The qPCRs evaluated in this study are technically suitable for the laboratory diagnostic assessment of clinical samples for infection with tick-borne pathogens. However, clinical validation and independent confirmation are still needed, pending the availability of sufficient human samples for testing in different laboratories. [ABSTRACT FROM AUTHOR]

Whiteflies ( Bemisia tabaci ) are a significant pest of cucurbits and vector many viruses, leading to substantial economic losses. Modern diagnostic tools offer the potential for early detection of viruses in the whiteflies before crop production. One such tool is the multiplex reverse transcriptase quantitative PCR (RT-qPCR) probe-based technique, which can detect multiple targets in a single reaction and simultaneously quantify the levels of each target, with a detection limit of 100 copies per target. In this study, a multiplex RT-qPCR-based detection system capable of identifying one DNA virus and three RNA viruses in whiteflies-cucurbit leaf crumple virus (CuLCrV), cucurbit chlorotic yellows virus (CCYV), cucurbit yellow stunting disorder virus (CYSDV), and squash vein yellowing virus (SqVYV)-was developed. To ensure the reliability of the assay, an internal gene control as the fifth target to monitor false-negative results was incorporated. This newly developed molecular diagnostic tool possesses several advantages. It can detect up to five desired targets from a single whitefly RNA sample, even at concentrations as low as 1 ng/μl. To evaluate its sensitivity, we conducted experiments using serially diluted cloned plasmids and in vitro transcribed RNA transcripts of the target viruses. We also assessed the specificity of the assay by including aphid-transmitted viruses and other viruses known to infect cucurbits. The diagnostic method successfully detected all five targets simultaneously and allowed for the quantification of up to 100 copies using a mixture of healthy RNA and in vitro transcribed RNA. Our aim with this study was to develop a highly specific and sensitive one-step multiplex RT-qPCR system for the simultaneous detection of viruses transmitted by whiteflies in cucurbits. This system offers significant advantages for early detection, enabling prompt control measures to mitigate the further spread of viral infections and reduce yield losses. Additionally, we demonstrated the ability to simultaneously detect mixed viruses (CCYV, CYSDV, CuLCrV, and SqVYV) in individual whiteflies and quantify the number of viral copies carried by each whitefly. The multiplex RT-qPCR assay outperforms currently available techniques for detecting many samples at a given time and can be effectively utilized for early monitoring of plant viruses in individual whiteflies and symptomless plants., Competing Interests: The author(s) declare no conflict of interest.

Modern forensic DNA quantitation assays provide information on the suitability of a DNA extract for a particular type of analysis, on the amount of sample to put into the analysis in order to yield an optimal (or best possible) result, and on the requirement for optional steps to improve the analysis. To achieve a high sensitivity and specificity, these assays are based on quantitative PCR (qPCR) and analyze target DNA loci that are present in multiple copies distributed across the genome. These target loci allow the determination of the amount of DNA, the degree of DNA degradation, and the proportion of DNA from male contributors. In addition, internal control DNA of a known amount is analyzed in order to inform about the presence of PCR inhibitors. These assays are nowadays provided as commercial kits that have been technically validated and are compatible with common qPCR instruments. In this review, the principles of forensic qPCR assays will be explained, followed by information on the nature of DNA loci targeted by modern forensic qPCR assays. Finally, we critically draw attention to the current trend of manufacturers not to disclose the exact nature of the target loci of their commercial kits.

Abstract Background The incidence of colorectal cancer (CRC) has increased during recent years in Iran and other developing countries. Clinical studies suggest that essential folate dietary intake and moderate deficiency of methylenetetrahydrofolate reductase (MTHFR) may protect and reduce the risk of CRC. The present study aimed to investigate the clinical significance of C677T polymorphism within the MTHFR gene and its correlation with the serum folate and Vit B12 in the Iranian population suffering from CRC. Methods Blood samples were taken from 1017 Iranian individuals (517 cases and 500 controls) who were referred for colonoscopy. TaqMan probe assay was performed for C677T MTHFR polymorphism. Sera were fractionated from the blood samples of 43 patients and controls and folate and Vit B12 concentrations were measured by a monobind kit. The correlation of MTHFR polymorphisms and folate/vitamin-B12 with CRC risk was analyzed. Results In the current study, we found the frequency of three different genotypes of MTHFR polymorphism in the Iranian population i.e., CC, CT, and TT, to be 51.31, 26.73, 21.96 and 61, 32.2, 6.8 in case and control groups, respectively. The homozygote genotype of MTHFR rs1801133 polymorphism is associated with an increased risk of CRC by 3.68, 1.42, and 3.74-fold in codominant, dominant, and recessive models respectively (p value 0.05). Conclusions This study revealed that there was no significant difference between the amount of folate and Vit B12 in the case and control groups. Furthermore, our results demonstrated a higher risk association for 677TT and 677TT + C677T genotypes of MTHFR compared with 677CC carriers among CRC patients.

P. brasiliense is an important bacterial pathogen causing blackleg (BL) in potatoes. Nevertheless, P. brasiliense is often detected in seed lots that do not develop any of the typical blackleg symptoms in the potato crop when planted. Field bioassays identified that P. brasiliense strains can be categorized into two distinct classes, some able to cause blackleg symptoms and some unable to do it. A comparative pangenomic approach was performed on 116 P. brasiliense strains, of which 15 were characterized as BL-causing strains and 25 as non-causative. In a genetically homogeneous clade comprising all BL-causing P. brasiliense strains, two genes only present in the BL-causing strains were identified, one encoding a predicted lysozyme inhibitor Lprl (LZI) and one encoding a putative Toll/interleukin-1 receptor (TIR) domain-containing protein. TaqMan assays for the specific detection of BL-causing P. brasiliense were developed and integrated with the previously developed generic P. brasiliense assay into a triplex TaqMan assay. This simultaneous detection makes the scoring more efficient as only a single tube is needed, and it is more robust as BL-causing strains of P. brasiliense should be positive for all three assays. Individual P. brasiliense strains were found to be either positive for all three assays or only for the P. brasiliense assay. In potato samples, the mixed presence of BL-causing and not BL-causing P. brasiliense strains was observed as shown by the difference in Ct value of the TaqMan assays. However, upon extension of the number of strains, it became clear that in recent years additional BL-causing lineages of P. brasiliense were detected for which additional assays must be developed.

Objective: A rapid and sensitive method to detect the proportion of mouse cell infiltration in PDX model was established in order to ensure the fidelity of PDX model. Methods: Partial segments of human and mouse specific genes PSMB2 and Ren2 were selected to design primers and probes, and the relative amount of mouse-human cells in PDX model was detected by multiplex fluorescence quantitative PCR (TaqMan probe method） in a single tube. In addition, we also constructed standards with different infiltration ratios as positive controls, and calculated the sample proportion according to the standard curve. Results: We established a method to detect the proportion of mouse cell infiltration in PDX model by multiplex fluorescence quantitative PCR. The scheme showed that there was a good linear relationship between different proportions of human and mouse mixed samples and △Ct value (Ct mouse-Ct human） in PDX model, and the correlation coefficient r² was 0.9998. This method was used to detect 14 samples, and the results showed that in most of the samples, the proportion of mouse cell was less than 30%, and the average proportion of mouse cell was 13.38%. Conclusion: The multiplex quantitative PCR method established in this study to detect the proportion of mouse cell infiltration in PDX model can quickly and accurately infer the proportion of human and mouse cells in PDX model according to △Ct value. This method has the advantages of simple operation, short time-consuming and reliable results, and provides a fast and sensitive quality control scheme for PDX model. [ABSTRACT FROM AUTHOR]

Ceratocystis platani (CP), an ascomycetous fungus, is the agent of canker stain, a lethal vascular disease of Platanus species. Ceratocystis platani has been listed as a quarantine pest (EPPO A2 list) due to extensive damage caused in Southern Europe and the Mediterranean region. As traditional diagnostic assays are ineffective, a Real-Time PCR detection method based on EvaGreen, SYBR Green, and Taqman assays was previously developed, validated in-house, and included in the official EPPO standard PM7/14 (2). Here, we describe the results of a test performance study performed by nine European laboratories for the purpose of an interlaboratory validation. Verification of the DNA extracted from biological samples guaranteed the high quality of preparations, and the stability and the homogeneity of the aliquots intended for the laboratories. All of the laboratories reproduced nearly identical standard curves with efficiencies close to 100%. Testing of blind-coded DNA extracted from wood samples revealed that all performance parameters—diagnostic sensitivity, diagnostic specificity, accuracy and reproducibility—were best fit in most cases both at the laboratory and at the assay level. The previously established limit of detection, 3 fg per PCR reaction, was also validated with similar excellent results. The high interlaboratory performance of this Real-Time PCR method confirms its value as a primary tool to safeguard C. platani-free countries by way of an accurate monitoring, and to investigate the resistance level of potentially canker stain-resistant Platanus genotypes. [ABSTRACT FROM AUTHOR]

The muscle from Xilingol indigenous sheep breeds are famous in China, and the FecB genotype in this population remains uncharacterized. In this study, SNPs in the FecB locus were investigated by pyrosequencing, and an optimized PCR‐RFLP technique was generated to identify SNPs. In addition, an efficient technique for high‐throughput identification of SNPs in FecB was optimized using TaqMan real‐time PCR and breed‐conservative primers and SNP‐specific probes. By genotyping the FecB locus in the muscle of Xilingol indigenous sheep breeds using a novel TaqMan real‐time PCR assay, our study has generated the groundwork for the authentication of Xilingol mutton based on the specific gene and the prolificacy‐oriented breeding of Xilingol sheep using marker‐assisted selection strategies in the future. [ABSTRACT FROM AUTHOR]

Tilapia parvovirus (TiPV) is a novel parvovirus associated with high mortality in Nile tilapia and red hybrid tilapia, leading to severe economic losses for tilapia aquaculture. It is critical to develop a sensitive and accurate assay to detect TiPV in fish tissues. In this study, new TaqMan probe‐based quantitative PCR (qPCR) assays targeting the non‐structural (NS) and viral protein (VP) genes of TiPV were developed. The standard curves of the assays were 95.64%–98.96% over a wide linear range of 109–101 copies of the corresponding standard DNA per reaction. The intra‐ and inter‐assay coefficients of variation were in the ranges 0.54%–2.50% and 0.13%–1.17%, respectively, which suggests good repeatability and reproducibility. The detection limit of the TaqMan TiPV assays was 10 copies/µl. The application of the TaqMan qPCR assays to field samples revealed that they had comparable sensitivity to a previously developed SYBR Green qPCR, but more sensitive than the conventional PCR. No cross‐reactivity of the TaqMan TiPV assays was found with the samples infected with other viruses and bacteria. Overall, the assays offered high sensitivity and specificity in the detection of low concentrations of TiPV DNA in infected tilapia samples. These new TaqMan qPCR assays could provide a valuable diagnostic tool for the reliable and specific detection of TiPV in experimental and field samples. [ABSTRACT FROM AUTHOR]

Background and Aim: Sexually infections transmitted by bacteria are one of thetherapeutic and social problems worldwide. The Real-time PCR assay is one of the most sensitive diagnostic and screening methods for these infections. The purpose of this study was simultaneous detection of Chlamydia trachomatis and Mycoplasma genitalium using the TaqMan duplex real-time polymerase chain reaction. Materials and Methods: In the present study, we used extracted DNA from women with vaginal infections available in the bank ofthe molecular and medical research center, Arak University of Medical Sciences, Arak, Iran. The duplex real-time PCR was evaluated to detect Chlamydia trachomatis and Mycoplasma genitalium in 110 vaginal and endocervical samples. To validate the diagnostic performance of the designed method, the tests were compared with a commercial diagnostic kit. Results: The size of the amplicons OmpA, 135 bp and MgPa, 145bp, indicated the accuracy of the primers designing procedures. The analysis of a panel of human STI revealed no cross-reactivity in the method. The diagnostic sensitivity and specificity of developed TaqMan duplex real-time PCR were 97% and 75%, respectively, compared to a commercial diagnostic kit. Conclusion: The results indicated that the used TaqMan duplex real-time PCR technique is specific and cost-effective and can be an excellent alternative to commercial kits for simultaneously detecting C. trachomatis and M. genitalium. Although the disadvantage of this method is its high cost, this disadvantage has significantly been resolved by the multiplex method. [ABSTRACT FROM AUTHOR]