Specific Polymerase Chain Reaction Research Articles

A putatively novel papillomavirus associated with cutaneous plaques and squamous cell carcinoma in captive North American snow leopards (Panthera uncia).

Cutaneous plaques and squamous cell carcinoma (SCC) are common in captive North American snow leopards (SLs) (Panthera uncia). Our objective was to determine whether these lesions are potentially associated with papillomavirus(es). Polymerase chain reaction (PCR) was performed on 3 cutaneous plaques using degenerate primers for papillomaviruses. A putatively novel papillomavirus was identified that shared 76% sequence identity to Felis catus papillomavirus 2. Specific PCR for this virus was performed on 5 cutaneous SCC samples and 7 normal skin samples, which were all positive. In situ hybridization for this putatively novel virus was performed, which revealed strong hybridization signals within hyperplastic cells in cutaneous plaques (n = 3) and within neoplastic cells in cutaneous SCC samples (n = 5). No hybridization signals were identified within normal skin. Ultimately, identification of a causal viral agent in the development of plaques and SCC in SLs will help guide therapeutic intervention and lay the foundation for development of prophylactic vaccines.

Development of a multiplex real-time quantitative reverse-transcription polymerase chain reaction for the detection of four bee viruses

Viruses in the families Dicistroviridae and Iflaviridae are among the main threats to western honey bees (Apis mellifera) and native bee species. Polymerase chain reaction (PCR) is the gold standard for pathogen detection in bees. However, high throughput screening for bee virus infections in singleplex PCR reactions is cumbersome and limited by the high quantities of sample RNA required. Thus, the development of a sensitive and specific multiplex PCR detection method for screening for multiple viruses simultaneously is necessary. Here, we report the development of a one-step multiplex reverse-transcription quantitative polymerase chain reaction (RT-qPCR) assay to detect four viruses commonly encountered in pollinator species. The optimized multiplex RT-qPCR protocol described in this study allows simultaneous detection of two dicistroviruses (Israeli acute paralysis virus and Black queen cell virus) and two iflaviruses (Sacbrood virus and Deformed wing virus) with high efficiency and specificity comparable to singleplex detection assays. This assay provides a broad range of detection and quantification, and the results of virus quantification in this study are similar to those performed in other studies using singleplex detection assays. This method will be particularly useful for data generation from small-bodied insect species that yield low amounts of RNA.

Prognostic value of BRCA1 promoter methylation for patients with epithelial ovarian cancer

ObjectiveBRCA1 promoter methylation (BRCA1pm) is suspected to alter prognosis of patients with epithelial ovarian cancer (EOC). We aimed to evaluate the prognostic impact of this epigenetic modification. MethodsWe conducted a retrospective, monocentric study from 11/2006 to 08/2018. Patients with EOC and available status concerning somatic BRCA1/2 mutation and BRCA1pm were included. Three groups were defined: patients without BRCA1/2 mutation or BRCA1pm, patients with BRCA1/2 mutation and patients with BRCA1pm. BRCA1/2 mutations were analyzed in current care settings by next-generation sequencing (NGS). BRCA1pm analysis was assessed and quantified from bisulfite converted DNAs using fluorescent methylation specific polymerase chain reaction (PCR) and fragment analysis. All patients signed a consent form and the study was authorized by a Personal Protection Committee. Descriptive statistics were used to describe groups. Multivariate analysis was performed using the logistic regression model and including the variables that could be known at the time of diagnosis and that were significant at univariate analysis. Survival was compared between the groups. Kaplan-Mayer curves were used to express the differences in survival that were compared using log rank tests. Results145 patients were included: 95 (65.5 %) patients without BRCA1/2 mutation or BRCA1pm, 32 (22.1 %) patients with BRCA1/2 mutation, 18 (12.4 %) patients with BRCA1pm. Median survival was decreased in patients with BRCA1pm. Comparison of survival revealed a significant difference in overall survival (p = 0.0078) with a worse prognosis for patients with a BRCA1pm. ConclusionBRCA1pm in patients with EOC is an independent factor associated with a decreased overall survival. SynopsisBRCA1 promotor methylation in patients with epithelial ovarian cancer is an independent factor associated with a decreased overall survival.

Development and evaluation of a multi-target droplet digital PCR assay for highly sensitive and specific detection of Yersinia pestis.

Plague, caused by the bacterium Yersinia pestis, is a zoonotic disease that poses considerable threats to human health. Nucleic acid tests are crucial for plague surveillance and the rapid detection of Y. pestis. However, inhibitors in complex samples such as soil and animal tissues often hamper nucleic acid detection, leading to a reduced rate of identifying low concentrations of Y. pestis. To address this challenge, we developed a sensitive and specific droplet digital polymerase chain reaction (ddPCR) assay for detecting Y. pestis DNA from soil and animal tissue samples. Three genes (ypo2088, caf1, and pla) from Y. pestis were used to develop a multi-target ddPCR assay. The limits of detection (LoD), reproducibility, and specificity were assessed for bacterial genomic DNA samples. The ability of the assay to detect low concentrations of Y. pestis DNA from simulated soil and mouse liver tissue samples was respectively evaluated and compared with that of quantitative real-time PCR (qPCR). The results showed that the ddPCR LoDs ranged from 6.2 to 15.4 copies/reaction for the target genes, with good reproducibility and high specificity for Y. pestis. By testing 130 soil and mouse liver tissue samples spiked with Y. pestis, the ddPCR assay exhibited a better sensitivity than that of the qPCR assay used in the study, with LoDs of 102 colony forming units (CFU)/100 mg soil and 103 CFU/20 mg liver. Moreover, the assay presented good quantitative linearity (R2 = 0.99) for Y. pestis at 103-106 CFU/sample for soil and liver samples. The ddPCR assay presented good performance for detecting Y. pestis DNA from soil and mouse tissue samples, showing great potential for improving the detection rate of low concentrations of Y. pestis in plague surveillance and facilitating the early diagnosis of plague cases.

Role of ABCC2 gene polymorphism on deferasirox hepatic toxicity in thalassemia patients

Objectives: To investigate the relationship between ABCC2 gene polymorphism (G>A, rs 8187710) and (C>T, rs 717620) and hepatotoxicity in thalassemia patient treated deferasirox . Methods: The present work included a cross sectional study, 100 patients suffering iron overload and thalassemia out of 650 patients in (thalassemia center) and 100 healthy patients to compare the parameters of liver function tests of thalassemia patients with healthy group. The allele specific polymerase chain reaction technique (pcr) was used to detect the (G>A, rs 8187710) and (C>T, rs 717620 single nucleotide polymorphism (SNP). Results : 58 patients with rs 8187710 who are wild (GG) and 32 patients hetero(GA)and 56 patients with rs 717620 who wild (CC) and 31 hetero (CT) are exposed to hepatotoxicity than patients with homo groups Conclusion: According to the results of the currents study, the (G>A, rs 8187710) and (C>T, rs 717620) single nucleotide polymorphism (SNP) was associated with hepatotoxicity in patients treated deferasirox.

Molecular Analysis of Antibiotic Resistance in CarbapenemResistant Pseudomonas aeruginosa Isolates Isolated from Clinical Samples

Pseudomonas aeruginosa is an opportunistic pathogen that causes increased morbidity and mortality in risky patient groups. Nowadays, carbapenem resistance has become a threat and resistance genes are spreading among species through mobile genetic elements. The dissemination of carbapenemases among P.aeruginosa is a serious public health concern due to its limited options for the treatment of bacterial infections. In this study, it was aimed to investigate the molecular epidemiology of 47 carbapenem resistant P.aeruginosa (CRPA) isolates derived from various clinical samples from the Central Laboratory Bacteriology Unit of Kocaeli University Research and Training Hospital between October 2021 and March 2023. The rates of resistance to the antibiotics, some carbapenemase and virulence genes, conjugative resistance plasmids, integron gene cassette contents and the clonal similarity of the isolates were investigated and then epidemiologically evaluated. In the study, identification of the bacterial isolates and their susceptibility to some antibiotics (imipenem, meropenem, aztreonam, amikacin, netilmicin, tobramycin, piperacillin, piperacillin/tazobactam, ceftazidime, cefepime, ciprofloxacin and levofloxacin) were determined by the VITEK® 2 Compact automated system. Metallo-beta-lactamase (MBL) production of the isolates was demonstrated by the imipenem/meropenem-EDTA (IMP/MEM-EDTA) combined disc method. Conjugation experiments were performed by the broth mating method. Alkali lysis method was used in plasmid DNA isolations. Co-transferred antibiotic resistances in transconjugants were detected by disc diffusion method. Carbapenemase genes (blaIMP , blaVIM , blaNDM , blaKPC and blaOXA-48 ), integron gene cassettes (class 1 and class 2) and virulence genes (lasR and rhlR) were screened by specific polymerase chain reactions (PCRs). Clonal relationships of the CRPA isolates were investigated by evaluating the DNA f ingerprintings obtained from the ERIC (enterobacterial repetitive intergenic consensus)-PCR assay. The highest resistance rate of the isolates were to levofloxacin, while the lowest resistance rates were observed against tobramycin, gentamicin and amikacin. MBL production was detected in 25 (53.2%) isolates. In conjugation experiments, 12 (25.5%) isolates were detected to harbour conjugative resistance plasmids. In 90% of the CRPA isolates, lasR and rhlR biofilm genes (encoding for the transcriptional activator protein) were detected by PCR. The blaVIM gene was detected in six (12.8%) isolates. The blaNDM gene was detected in five (10.6%) isolates and the blaOXA-48 gene was detected in three (6.4%) isolates. The blaKPC and blaIMP genes were not detected in CRPA isolates. It was determined that two (16.6%) of the isolates that carried the blaVIM gene, one (8.3%) carried the blaNDM gene and one (8.3%) carried the blaOXA-48 gene contained conjugative plasmids.In integron-specific PCRs, intI1 gene was positive in 39 (82.9%) isolates, while class 1 integron gene cassettes were detected in 24 isolates (51%). IntI1 positive six isolates were found to harbour class 1 integron gene cassettes-bearing conjugative plasmids. Class 2 integrons were not found in the CRPA isolates. Dendrogram analysis of ERIC-PCR patterns showed that there was no clonal similarity between the CRPA isolates and the isolates did not spread by cross-contamination. As a result, it has been observed that most of the CRPA isolates which have the potential to form biofilms, are highly resistant to other antibiotic groups other than carbapenems and can co-transfer some resistances (ceftazidime, cefepime, ciprofloxacin, levofloxacin, piperacillin-tazobactam) with conjugative resistance plasmids. It is thought that it would be useful to follow molecular epidemiology in the resistance gene reservoirs of these strains which have the potential to cause epidemics in the clinical arena.

Development of a High-throughput Sequencing Platform for Detection of Viral Encephalitis Pathogens Based on Amplicon Sequencing*

ObjectiveViral encephalitis is an infectious disease severely affecting human health. It is caused by a wide variety of viral pathogens, including herpes viruses, flaviviruses, enteroviruses, and other viruses. The laboratory diagnosis of viral encephalitis is a worldwide challenge. Recently, high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections. Thus, In this study, we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing. MethodsWe designed nine pairs of specific polymerase chain reaction (PCR) primers for the 12 viruses by reviewing the relevant literature. The detection ability of the primers was verified by software simulation and the detection of known positive samples. Amplicon sequencing was used to validate the samples, and consistency was compared with Sanger sequencing. ResultsThe results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×, and the sequence lengths were consistent with the sizes of the predicted amplicons. The sequences were verified using the National Center for Biotechnology Information BLAST, and all results were consistent with the results of Sanger sequencing. ConclusionAmplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis. It is also a useful tool for the high-volume screening of clinical samples.

Identification ofantibiotic resistance genes inEscherichia coli from subclinical mastitis milk indairy cows and goats, East Java Province.

Antibiotics are still used totreat mastitis indairy cows inIndonesia. This study aimed toanalyse antibiotic resistance genes inEscherichia coli (E.coli) from subclinical mastitis milk inEast Java Province, Indonesia. Thesamples consisted ofsubclinical mastitis milk from cows and goats. Atotal of592-quarter cow's milk and 71goat's milk samples from both halves ofthe udder were collected from 67farms inLumajang, Banyuwangi, Malang, Sidoarjo, Jember, Pasuruan, Probolinggo, and Mojokerto. Subclinical mastitis samples were screened using the California mastitis test (CMT). E.coli was identified byphenotypic and genotypic methods. E.coli wasconfirmed with aprimer specific tothe polymerase chain reaction (PCR) technique. Gene resistance ofE.coli was tested using the multiplex-PCR (mPCR) technique with primers encoding the genes temoneira enzyme (TEM), oxacillinase (OXA), sulfhydryl variable (SHV), and cefotaximase-munich IV (CTX-M IV). These genes were chosen because mastitis treatment generally uses oxacilline and β-lactam antibiotics. All data obtained were analysed descriptively. Theresults show that six isolates ofE.coli (46.15%) carried asingle resistance gene (TEM orSHV) and two isolates (33.33%) were confirmed asmultiple drug-resistant organisms (MDROs) (TEM and SHV). Theresistance genes were found insamples originating from Blitar, Banyuwangi, Lumajang, and Pasuruan Regencies. This research implies that antibiotic-resistance genes found inE.coli oncertain farms are dangerous and may allow gene transmission toother bacteria that make treatment for mastitis orother bacterial infections ineffective.

The Impact of Genetic Polymorphisms in (STIM1 and ORAI1) on Erythropoietin Resistance in Patients with Chronic Renal Failure on Hemodialysis in Iraq

Objective: This study aims to investigate the correlation between genetic polymorphisms in store-operated calcium channels (SOCs) signaling and resistance to erythropoietin treatment in patients with chronic renal failure (CRF). Anemia is a significant complication of CRF, and understanding the genetic factors contributing to resistance could provide insights into potential mechanisms influencing treatment outcomes. Specifically, the focus is on exploring the relationship between SOCs, a pathway activated by erythropoietin, and resistance to address the challenges associated with anemia in CRF patients.
 Methods: In this study, a single nucleotide polymorphism in each STIM1 and ORAI1 gene was selected. Genotyping was done by using allele specific polymerase chain reaction technique and the data was analyzed through the Statistical Package for the Social Sciences. 112 patients with CRF on hemodialysis were enrolled 58.9% of them were men and the mean age was 50.94±13.42.
 Results: We found that CC genotype of ORAI1 gene has a higher hemoglobin level, AA genotype of STIM1 has a higher EPO level, the interaction of the two genes showed that CCGG group has a higher Hb level and is considered good responder but represents only 4.5% of the patients
 Conclusion: After all the genetic polymorphisms of SOCs genes ORAI1 and STIM1 have no significant impact on erythropoietin resistance in patients with CRF on hemodialysis in Iraq.

Exploring the Impact of Primer-Template Mismatches on PCR Performance of DNA Polymerases Varying in Proofreading Activity.

Polymerase chain reaction (PCR) is a widely used technique in gene expression analysis, diagnostics, and various molecular biology applications. However, the accuracy and sensitivity of PCR can be compromised by primer-template mismatches, potentially leading to erroneous results. In this study, we strategically designed 111 primer-template combinations with varying numbers, types, and locations of mismatches to meticulously assess their impact on qPCR performance while two distinctly different types of DNA polymerases were used. Notably, when a single-nucleotide mismatch occurred at the 3' end of the primer, we observed significant decreases in the analytical sensitivity (0-4%) with Invitrogen™ Platinum™ Taq DNA Polymerase High Fidelity, while the analytical sensitivity remained unchanged with Takara Ex Taq Hot Start Version DNA Polymerase. Leveraging these findings, we designed a highly specific PCR to amplify Babesia while effectively avoiding the genetically close Theileria. Through elucidating the critical interplay between types of DNA polymerases and primer-template mismatches, this research provides valuable insights for improving PCR accuracy and performance. These findings have important implications for researchers aiming to achieve robust qPCR results in various molecular biology applications.

Molecular and next-generation sequencing analysis of tick-borne pathogens of Rhipicephalus ticks (Acari: Ixodidae) in cattle and dogs

Ticks are small and adaptable arachnid ectoparasites and global carriers of various pathogens that threaten both human and animal health. They are present in many parts of China. A total of 858 ticks were collected from various regions and hosts, then subjected to species identification based on morphological and molecular characteristics, as described in the authors’ previous study. Eighty-three individual tick samples were selected for screening pathogens based on metagenomic next-generation sequencing (mNGS) and polymerase chain reaction (PCR) assays. The genomic DNA of tick species was extracted, and amplification of the bacterial 16S rRNA gene was carried out from DNA of individual ticks using V3-V4 hypervariable regions, before subjecting to metagenomic analysis. Each tick underwent specific PCR tests for identifying the bacterial species present, including Anaplasma, Ehrlichia, Coxiella, and Rickettsia, and also protozoans such as Babesia, Theileria, and Hepatozoon. Illumina NovaSeq sequencing results revealed that the dominant phylum and family in Rhipicephalus spp. were Bacteroidota and Muribaculaceae, respectively. Alpha diversity patterns varied depending on tick sex (R. linnaei only), species and location, but not on host. Furthermore, bacterial pathogens, including A. marginale (58 %, 29/50), A. platys (6 %, 3/50), E. minasensis (2 %, 1/50), Ehrlichia sp. (10 %, 5/50), T. sinensis (24 %, 12/50), T. orientalis (54 %, 27/50) and Coxiella-like bacteria (CLB) (80 %, 40/50) were detected in R. microplus, while E. canis (33.33 %, 10/30), H. canis (20 %, 6/30) and CLB (100 %, 30/30) were detected in R. linnaei. Also, Anaplasma sp. (33.33 %, 1/3), A. marginale (33.33 %, 1/3), R. felis (33.33 %, 1/3) and CLB (100 %, 3/3) were detected in R. haemaphysaloides. Dual and triple co-infections involving pathogens or CLB were detected in 84.00 % of R. microplus, 66.66 % of R. haemaphysaloides, and 33.00 % of R. linnaei. The report on microbial communities and pathogens, which found from Rhipicephalus spp. in Hainan Island, is an important step towards a better understanding of tick-borne disease transmission. This is the first report in the area on the presence of Anaplasma sp., A. marginale, R. felis and Coxiella, in R. haemaphysaloides.

Prevalence of Rhodococcus equi in foals of west northern Rajasthan by Vap A and Vap C genes specific polymerase chain reaction

Prevalence of Rhodococcus equi in foals of west northern Rajasthan by Vap A and Vap C genes specific polymerase chain reaction

Analysis of β-casein gene for A1 and A2 allelic variants in Holstein-Local crossbred cattle of Bangladesh using allele-specific PCR

Beta-casein (CSN2) is one of the important bovine milk proteins synthesized by β-casein gene. The aim of this study was to investigate the A1 and A2 allelic variants of CSN2 gene in Holstein-Friesian and Local (HF×L) crossbred cattle of Bangladesh. Allele specific polymerase chain reaction (AS-PCR) was carried out for genotyping of allelic variants. A total of 390 blood samples of HF×L crossbred cattle was included from govt., military and private dairy farms. Six different crossbred genotypes were identified in the studied population as 50%HF×50%L, 62.5%HF×37.5%L, 68.75%HF×31.25%L, 75%HF×25%L, 81.25%HF×18.75%L and 87.5%HF×12.5%L. The mean frequencies of the A1A1, A1A2, and A2A2 genotypes were 0.11, 0.48, and 0.41, respectively, while the corresponding frequencies of the A1 and A2 alleles were 0.34 and 0.66, respectively. The frequency of desirable A2A2 genotype reduced from 0.60 (50%HF×50%L) to 0.38 (87.5%HF×12.5%L) with the advancement of exotic HF inheritance from 50 to 87.5%. In contrast, the frequency of A1A1 and A1A2 genotypes increased proportionately with the progression of HF inheritance level. The undesirable A1A1 genotype frequency was found highest in the HF crossbreds of private dairy farms (0.13) compared to government (0.08) and military dairy farm (0.07) that signifies the availability of upper graded cows in the private dairy farms. Altogether, this study provides current scenario of A1 and A2 allelic variants of HF×L crossbreds of Bangladesh that could be utilized to design suitable breeding plans in crossbreeding programs for production of premium quality milk.

Comparative studies on the detection of Theileria annulata infection by clinical, parasitological and molecular techniques in buffaloes (Bubalus bubalis)

During the period of 2019-2021, a total of 715 buffaloes were screened for Theileria infections. A set of clinical parameters were used to identify the theileriosis suspected animals which were later confirmed through microscopic tests (peripheral thin blood smear examination and lymph node biopsy smear examination) and molecular assay (cytochrome b based T. annulata specific polymerase chain reaction test). On the basis of clinical evaluation, 33.43% (239/715) buffaloes were suspected for the presence of theileriosis. Through laboratory examination, 63.60% (152/239), 7.48% (16/214) and 100% (239/239) were found positive for Theileria infection by blood smear examination, lymph node biopsy and PCR, respectively, among the clinically suspected theileriosis animals. The efficiency of PCR was recorded to be highest, followed by microscopic examination of peripheral blood smears, and the lowest value was obtained for lymph node biopsy smear examination. The results indicated that PCR is a highly sensitive diagnostic technique for confirmatory diagnosis of T. annulata parasitic infection in buffaloes, even at very low level of parasitemia. Analysis of the data based on thin blood smear examination revealed that the field incidence of theileriosis was 11.55% in the south-western region of Gujarat, India. The high incidences of T. annulata infection in buffaloes may be due to the sub-tropical climate of the region which is favorable for the growth and development of vector ticks and parasites.

Association between HLA-B*27:04 and genetic susceptibility to ankylosing spondylitis in Hunan Province.

Human leukocyte antigen (HLA) B27 is a susceptibility allele of ankylosing spondylitis (AS), and HLA-B27 antigen typing is an important indicator for clinical diagnosis of AS, but current typing methods such as sequence specific primer polymerase chain reaction (PCR-SSP) still possess limitation. Therefore, this study aims to analyze the correlation between B27 subtypes and susceptibility to AS in Hunan Province by applying high-resolution polymerase chain reaction-sequence-based typing (PCR-SBT). Peripheral blood of 116 patients with suspected AS (suspected AS group) and 121 healthy volunteers (control group) admitted to the Second Xiangya Hospital from January 2020 to December 2020 were collected for HLA-B genotyping by PCR-SBT. Among the patients in the suspected AS group, 23 patients were finally diagnosed with AS (confirmed AS group), and the remaining 93 undiagnosed patients served as the non-confirmed AS group. PCR-SBT and PCR-SSP were used to detect HLA-B27 typing in 116 patients with suspected AS, and the results of the 2 methods were compared. The HLA-B27 allele frequency in the suspected AS group was significantly higher than that in the control group [11.63% vs 2.48%; P<0.001, odds ratio (OR)=5.18, 95% confidence interval (CI) 2.097 to 12.795]. B*27:04, B*27:05, B*27:06, and B*27:07 were detected in the suspected AS group and the control group. The frequency of the B*27:04 allele in the suspected AS group was significantly higher than that in the control group (9.48% vs 1.24%; P<0.001, OR=8.346, 95% CI 2.463 to 28.282). The positive rate of B27 in the suspected AS group and the confirmed AS group (B27+/+ and B27+/-) was significantly higher than that in the control group (χ2=16.579, P<0.001; χ2=94.582, P<0.001, respectively). Among the confirmed AS group, 21 were HLA-B27 carriers, and the B27 positive rate in the confirmed AS group was 91.3%. PCR-SBT could achieve high resolution typing of the HLA-B gene locus, with higher sensitivity, specificity, positive predictive value, negative predictive value, and accuracy than PCR-SSP. PCR-SBT typing analysis shows a strong correlation between HLA-B * 27:04 and AS in Hunan province. The PCR-SBT method can be used as the preferred option for the auxiliary diagnosis of clinical AS.

Protocolized polyoma BK viral load monitoring and high-dose immunoglobulin treatment in children after kidney transplant.

BKPyV virus nephropathy (BKPyVAN) is diagnosed in 5%-16% of pediatric renal transplant recipients (PRTR) and preceded by BKPyV-viruria and DNAemia. Despite the risk of irreversible transplant damage associated with BKPyVAN, evidence-based consensus guidelines for BKPyVAN prevention are still lacking. In this retrospective study, we examined the safety and efficacy of high-dose intravenous immunoglobulin (HD-IVIG) therapy for prevention of BKPyVAN in PRTR with significant BKPyV-viruria/DNAemia. Between January 2013 and December 2022, all PRTR under our care underwent routine urine and blood testing for BKPyV viral load, using specific polymerase chain reaction (PCR). BKPyV DNAemia, with<103 copies/mL, with BKPyV viruria<107 copies/mL, with no evidence of BKPyVAN, were managed with 50% dose reduction of mycophenolate mofetil (MMF). Patients showing no decline in BKPyV viral load within two months of MMF dose reduction were managed with HD-IVIG (2g/kg). Seventy patients were recruited during a ten-year period and 31/70 patients (44%) demonstrated significant post-transplantation BKPyV-viruria/DNAemia, while 13/31 (42%) patients were unresponsive to MMF dose reduction, and were administered HD-IVIG. Of these, 12/13 (92%) patients achieved BKPyV viral clearance within six months from completion of HD-IVIG therapy and 1/13 patient (8%) was unresponsive to HD-IVIG therapy, showing increased BKPyV viral load. There were no major adverse events associated with HD-IVIG, and none of our patients developed BKPyVAN during the study period. Prophylactic HD-IVIG therapy in PRTR with significant BKPyV-viruria/DNAemia unresponsive to MMF dose reduction is safe and might be effective in preventing BKPyVAN. Our findings remain to be established by large-scale prospective studies.

Development and evaluation of specific polymerase chain reaction assays for detecting Theileria equi genotypes

BackgroundTheileria equi causes equine piroplasmosis, an economically significant disease that affects horses and other equids worldwide. Based on 18S ribosomal RNA (18S rRNA sequences), T. equi can be classified into five genotypes: A, B, C, D, and E. These genotypes have implications for disease management and control. However, no conventional polymerase chain reaction (PCR) assays are available to differentiate the genotypes of T. equi. To overcome this limitation, we developed and evaluated PCR assays specific for the detection of each T. equi genotype.MethodsA pair of forward and reverse primers, specifically targeting the 18S rRNA sequence of each genotype, was designed. The genotype-specific PCR assays were evaluated for their specificity using plasmids containing inserts of the 18S rRNA sequence of each genotype. Subsequently, the assays were tested on 270 T. equi-positive equine blood DNA samples (92 from donkeys in Sri Lanka and 178 from horses in Paraguay). 18S rRNA sequences derived from the PCR amplicons were analyzed phylogenetically.ResultsEach genotype-specific PCR assay accurately targeted the intended genotype, and did not produce any amplicons when 18S rRNA from other T. equi genotypes or genomic DNA of Babesia caballi or uninfected horse blood was used as the template. Previous studies employing PCR sequencing methods identified T. equi genotypes C and D in the Sri Lankan samples, and genotypes A and C in the Paraguayan samples. In contrast, our PCR assay demonstrated exceptional sensitivity by detecting four genotypes (A, C, D, and E) in the Sri Lankan samples and all five genotypes in the Paraguayan samples. All the Sri Lankan samples and 93.3% of the Paraguayan samples tested positive for at least one genotype, further emphasizing the sensitivity of our assays. The PCR assays also had the ability to detect co-infections, where multiple genotypes in various combinations were detected in 90.2% and 22.5% of the Sri Lankan and Paraguayan samples, respectively. Furthermore, the sequences obtained from PCR amplicons clustered in the respective phylogenetic clades for each genotype, validating the specificity of our genotype-specific PCR assays.ConclusionsThe genotype-specific PCR assays developed in the present study are reliable tools for the differential detection of T. equi genotypes.Graphical abstract

Targeted long-read sequencing identifies and characterizes structural variants in cases of inherited platelet disorders

BackgroundGenetic diagnosis of inherited platelet disorders (IPDs) is mainly performed by high-throughput sequencing (HTS). These short-read–based sequencing methods sometimes fail to characterize the genetics of the disease. ObjectivesTo evaluate nanopore long-read DNA sequencing for characterization of structural variants (SVs) in patients with IPDs. MethodsFour patients with a clinical and laboratory diagnosis of Glanzmann thrombasthenia (GT) (P1 and P2) and Hermansky–Pudlak syndrome (HPS) (P3 and P4) in whom HTS missed the underlying molecular cause were included. DNA was analyzed by both standard HTS and nanopore sequencing on a MinION device (Oxford Nanopore Technologies) after enrichment of DNA spanning regions covering GT and HPS genes. ResultsIn patients with GT, HTS identified only 1 heterozygous ITGB3 splice variant c.2301+1G>C in P2. In patients with HPS, a homozygous deletion in HPS5 was suspected in P3, and 2 heterozygous HPS3 variants, c.2464C>T (p.Arg822∗) and a deletion affecting 2 exons, were reported in P4. Nanopore sequencing revealed a complex SV affecting exons 2 to 6 in ITGB3 (deletion-inversion-duplication) in homozygosity in P1 and compound heterozygosity with the splice variant in P2. In the 2 patients with HPS, nanopore defined the length of the SVs, which were characterized at nucleotide resolution. This allowed the identification of repetitive Alu elements at the breakpoints and the design of specific polymerase chain reactions for family screening. ConclusionThe nanopore technology overcomes the limitations of standard short-read sequencing techniques in SV characterization. Using nanopore, we characterized novel defects in ITGB3, HPS5, and HPS3, highlighting the utility of long-read sequencing as an additional diagnostic tool in IPDs.

Multiplex allele-specific polymerase chain reaction-based prevalence study of canine trapped neutrophil syndrome in Thailand.

Trapped neutrophil syndrome (TNS) is an autosomal recessive genetic disorder found in Border Collies and is characterized by peripheral neutropenia and myeloid hyperplasia of bone marrow. The underlying cause of TNS is associated with a 4-base pair deletion mutation in the vacuolar protein sorting 13 homolog B (VPS13B) gene. In this study, we proposed and validated a novel multiplex allele specific-polymerase chain reaction (MAS-PCR) technique to assess the prevalence of TNS using VPS13B genotypes of Border Collies and Thai Ridgebacks in Thailand. We assessed the prevalence of TNS in 100 Border Collies and 30 Thai Ridgebacks using MAS-PCR-based allelic discrimination technique of the VPS13B gene. We then confirmed the VPS13B genotypes by direct DNA sequencing. A total of 130 samples were successfully genotyped using MAS-PCR assays. Of the two dog breeds examined, the VPS13B mutation was present in Border Collies, whereas Thai Ridgebacks were unaffected by this mutation. In Border Collies, 96% of dogs tested had an intact VPS13B genotype, whereas the remaining individuals had a heterozygous mutation genotype, with prevalence and mutated VPS13B allele frequencies of 4% and 2%, respectively. Using a novel MAS-PCR assay targeting the VPS13B gene, this study demonstrates for the first time that carriers of TNS exist in Border Collies in Thailand. This assay is a reliable and cost-effective tool for diagnosing TNS based on VPS13B genotypes and is suitable for routine clinical practice.

CDKN2B-AS (rs2891168), SOD2 (rs4880), and PON1 (rs662) polymorphisms and susceptibility to coronary artery disease and type 2 diabetes mellitus in Iranian patients: A case-control study.

Coronary artery disease (CAD) is a devastating illness and primary cause of death worldwide that arises from a combination of genetic and environmental factors. Several large-scale studies found that 9p21.3, superoxide dismutase 2 (SOD2), and paraoxonase 1 (PON1) polymorphisms increase type 2 diabetes mellitus (T2DM) and/or coronary artery disease (CAD) risk. Our research aimed to investigate whether the SNPs of the 9p21.3 locus (rs28911698), SOD2 (rs4880), and PON1 (rs662) genes were associated with the risk of T2DM and/or CAD in the Iranian population. In this case-control study four group subjects including patients with CAD non-T2DM, with CAD and T2DM, non-CAD with T2DM, and non-CAD non-T2DM were recruited to the study from 2019 to 2020. Molecular analysis was carried out by allele specific-polymerase chain reaction (AS-PCR) technique for rs4880, Taqman genotyping assay for rs2891168, and PCR followed by restriction fragment length polymorphism (PCR-RFLP) technique for rs662. The rs2891168 polymorphism presented an elevated risk of CAD in non-T2DM with CAD and with T2DM CAD groups compared to the non-T2DM non-CAD group with GG genotype and dominant model after adjustment (p < 0.05). G-allele in PON1 rs662 polymorphism associated with increased risk of T2DM in T2DM non-CAD, and T2DM CAD groups compared to non-T2DM non-CAD group with dominant model, GG and AG genotypes (p < 0.05). However, SOD2 rs4880 polymorphism presented no significant association with the development of diabetes or CAD. These results provide a prime witness that rs2891168 and rs662 gene variants might have a possible increased risk of CAD and T2DM occurrence, respectively. To obtain more definitive and accurate results in this area, further research is required.