pcr assay
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2026 ◽  
Vol 65 (4) ◽  
pp. 479-483
Agnieszka Figas ◽  
Magdalena Wieczorek ◽  
Bogumiła Litwińska ◽  
Włodzimierz Gut

The work presented here demonstrates the utility of a two-step algorithm for environmental poliovirus surveillance based on: preselection of sewage samples tested for the presence of enteroviral genetic material-RT-PCR assay and detection of infectious viruses by cell culture technique (L20B for polioviruses and RD for polio and other non-polio enteroviruses). RD and L20B cell lines were tested to determine their sensitivity for isolation of viruses from environmental samples (sewage). Finally, we wanted to determine if sewage concentration affects the results obtained for RT-PCR and cell cultures.

Viruses ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 159
Robert A. Kozak ◽  
Candace Rutherford ◽  
Melissa Richard-Greenblatt ◽  
N. Y. Elizabeth Chau ◽  
Ana Cabrera ◽  

Hepatitis A virus (HAV) is an emerging public health concern and there is an urgent need for ways to rapidly identify cases so that outbreaks can be managed effectively. Conventional testing for HAV relies on anti-HAV IgM seropositivity. However, studies estimate that 10–30% of patients may not be diagnosed by serology. Molecular assays that can directly detect viral nucleic acids have the potential to improve diagnosis, which is key to prevent the spread of infections. In this study, we developed a real-time PCR (RT-PCR) assay to detect HAV RNA for the identification of acute HAV infection. Primers were designed to target the conserved 5′-untranslated region (5′-UTR) of HAV, and the assay was optimized on both the Qiagen Rotor-Gene and the BD MAX. We successfully detected HAV from patient serum and stool samples with moderate differences in sensitivity and specificity depending on the platform used. Our results highlight the clinical utility of using a molecular assay to detect HAV from various specimen types that can be implemented in hospitals to assist with diagnostics, treatment and prevention.

Le Thi Thanh Nhan ◽  
Nguyen Thuy Quynh ◽  
Le Lan Phuong ◽  
Bui Phuong Thao ◽  
Nguyen Thi Tu Linh ◽  

For the prevalence of lung cancer and its poor diagnosis, the seeking of the efficient biomarkers for this disease is an urgent requirement, especially from non-invasive samples such as plasma. The mitochondria DNA (mtDNA) copy number change has been evaluated as a potential indicator of cancer risk, however, there have been few studies regarding mtDNA in plasma derived exosomes. In this study, the mtDNA copy number was measured on 29 plasma exosome samples of patients with non-small cell lung cancer (NSCLC) and 29 plasma exosome samples of cancer-free controls by real-time PCR assay, then being statistically analyzed to evaluate the relationship between these figures and several pathological features of NSCLC patients. As the results, the existence of mtDNA in exosomes isolated from plasma was detected through PCR assay using primers covering most of the mtDNA length. The relative mtDNA copy numbers determined in the exosomes of the disease and control groups were 1619.1 ± 2589.0 and 1207.0 ± 1550.0, respectively, whereas these values in two disease stages were 783.6 ± 759.3 (stage I-II) and 2647.0 ± 3584.0 (stage III-IV). Comparing among these groups, the difference was only statistically significant between the disease groups of stage I-II and stage III-IV (p<0.05), the group of stage III-IV and the control group (p<0.05). Indeed, the mtDNA copy number is associated with tumor stage and stage N (p<0.05). On the other aspect, the smoking habit of NSCLC patients could be an underlying reason behind the alteration in mtDNA copy number in the plasma exosomes. In short, our study demonstrates that the mtDNA copy number in exosomes resourced from plasma could be a potential biomarker for the detection and prognosis of NSCLC.

2022 ◽  
Vol 12 ◽  
Susana Ruiz-Ruiz ◽  
Carolina A. Ponce ◽  
Nicole Pesantes ◽  
Rebeca Bustamante ◽  
Gianna Gatti ◽  

Here we report a new real-time PCR assay using SYBR Green which provides higher sensitivity for the specific detection of low levels of Pneumocystis jirovecii. To do so, two primer sets were designed, targeting the family of genes that code for the most abundant surface protein of Pneumocystis spp., namely the major surface glycoproteins (Msg), and the mitochondrial large subunit rRNA (mtLSUrRNA) multicopy gene, simultaneously detecting two regions. PCR methods are instrumental in detecting these low levels; however, current nested-PCR methods are time-consuming and complex. To validate our new real-time Msg-A/mtLSUrRNA PCR protocol, we compared it with nested-PCR based on the detection of Pneumocystis mitochondrial large subunit rRNA (mtLSUrRNA), one of the main targets used to detect this pathogen. All samples identified as positive by the nested-PCR method were found positive using our new real-time PCR protocol, which also detected P. jirovecii in three nasal aspirate samples that were negative for both rounds of nested-PCR. Furthermore, we read both rounds of the nested-PCR results for comparison and found that some samples with no PCR amplification, or with a feeble band in the first round, correlated with higher Ct values in our real-time Msg-A/mtLSUrRNA PCR. This finding demonstrates the ability of this new single-round protocol to detect low Pneumocystis levels. This new assay provides a valuable alternative for P. jirovecii detection, as it is both rapid and sensitive.

2022 ◽  
Vol 20 (6) ◽  
pp. 41-54
N. A. Smetannikova ◽  
M. A. Abdurashitov ◽  
A. G. Akishev ◽  
P. I. Pozdnyakov ◽  
E. V. Dubinin ◽  

Hypermethylation of the RcgY sites is shown for many cancer diseases. such aberrant methylation, suppressing the gene activity, occurs at early stages of carcinogenesis. Recently, using glad-pcR assay, we have detected aberrantly methylated RcgY sites, which can be considered to be epigenetic markers of colorectal, lung, and gastric cancers. in breast cancer, methylation of the regulatory regions of ALX4, BMP2, CCND2, CDH13, CDX1, FOXA1, GALR1, GATA5, GREM1, HIC1, HMX2, HS3ST2, HOXC10, ICAM5, LAMA1, RARB, RASSF1A, RUNX3, RXRG, RYR2, SFRP2, SOX17, TERT, and ZNF613 tumor-suppressor genes is reported. in the present work, we determined aberrantly methylated RcgY sites in the regulatory regions of these genes in dNa preparations from breast cancer tissues. the study of dNa samples from 30 tumor and 22 normal mammary tissue samples demonstrates a high diagnostic potential of selected R(5mc)gY sites in regulatory regions of CCND2, BMP2, GALR1, SOX17, HMX2, and HS3ST2 genes with total index of sensitivity and specificity for R(5mc)gY detection in tumor dNa 90.0 % and 100.0 %, respectively.

2022 ◽  
Vol 43 (1) ◽  
pp. 431-440
Flávia Carolina Meira Collere ◽  
Larissa Dantas Roeder Ferrari ◽  
Ricardo Nascimento Drozino ◽  
Jéssica Damiana Marinho Valente ◽  

The order Chiroptera is the second largest group of mammals with bats being identified as reservoir of several viral zoonoses, although, little is known about their role in other groups of pathogens, including hemotropic Mycoplasma spp. To date, hemoplasma species have been found infecting several species of bats with high genetic diversity between 16S rRNA gene sequences. On this study, we aimed to identify the occurrence and characterize 16S and 23S rRNA genes of hemoplasma species in four bats species (Artibeus lituratus, Carollia perspicillata, Sturnira lilium and Sturnira tildae) from forest fragments in Paraná State, southern Brazil, using PCR-based assays. Spleen tissue samples were collected, DNA extracted and further screened by a pan‑hemoplasma PCR assay. All samples consistently amplified the mammal endogenous gapdh gene. One out of 15 (6.66%; 95% CI: 0.2-31%) bats tested positive for hemotropic Mycoplasma sp. by the PCR assay targeting the 16S rRNA gene. Sequencing of the 16S rRNA gene fragment from the hemoplasma-positive bat showed 99.14% identity with hemotropic Mycoplasma sp. detected in Sturnira parvidens from Belize. Sequencing of the 23S rRNA gene fragment from the hemoplasma-positive bat showed 86.17% identity with ‘Candidatus Mycoplasma haemosphiggurus’ detected in orange-spined hairy dwarf porcupines (Sphiggurus villosus) from Southern Brazil.

Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 208
Gaurav Kumar ◽  
Jacqueline Cottalorda-Dufayard ◽  
Rodolphe Garraffo ◽  
Francine De Salvador-Guillouët ◽  
Eric Cua ◽  

Raltegravir (RLT) prevents the integration of HIV DNA in the nucleus, but published studies remain controversial, suggesting that it does not decrease proviral DNA. However, there are only a few studies focused on virus-targeted cells. We aimed our study on the impact of RLT inclusion on total intra-cellular viral DNA (TID) in cellular subsets and immune effects in patients with newly acquired undetectable plasmatic viral load (UVL). Six patients having UVL using an antiretroviral combination for 6 months and CD4 T-cells > 350/mL and <500/mL were selected to receive RLT for 3 months from M0 to M3. Patients had 7 sequential viro-immunological determinations from M-1 to M5. Immune phenotypes were determined by flow cytometry and TID quantification was performed using PCR assay on purified cells. TID (median values) at the initiation of RLT in CD4 T-cells was 117 copies/millions of cells, decreased to 27.5 on M3, and remained thereafter permanently under the cut-off (<10 copies/millions of cells) in 4 out of 6 patients. This was associated with an increase of CD4 and CD4 + CD28+ T-cells and a decrease of HLA-DR expression and apoptosis of CD4 T-cells. RLT inclusion led to decreases in the viral load along with positive immune reconstitution, mainly for CD4 T-cells in HIV patients.

2022 ◽  
Vemula Harshini ◽  
S.M.K. Karthickeyan ◽  
K.G P. Kumarasamy ◽  
Tirumurugaan ◽  
C. Jeevan

Abstract A SYBR green real-time PCR assay was developed to find out the sex skewness in bovine sex-sorted semen samples. The qPCR assay of PLP and SRY genes revealed the mean values of X- and Y-bearing spermatozoa as 50.24 ± 0.65 and 49.75 ± 0.62 per cent in unsorted, and 91.80 ± 0.79 and 8.20 ± 0.73 per cent in X-enriched semen samples respectively.. The amplification efficiencies of the PLP and SRY primers were 99.25 and 98.03 per cent respectively. The method was validated by a series of repeatability and reproducibility assays which revealed low co-efficients of variations as 2.19 and 3.12 per cent respectively Thus becoming a reliable and inexpensive tool to evaluate the sorted semen on routine basis and validation of other sperm sexing technologies.

2022 ◽  
Vol 12 (1) ◽  
Subeen Hong ◽  
Seung Mi Lee ◽  
Sohee Oh ◽  
So Yeon Kim ◽  
Young Mi Jung ◽  

AbstractTo examine the detection performance of a peptide nucleic acid (PNA) probe-based real-time time polymerase chain reaction (PCR) assay to detect common aneuploidies. Using amniotic fluid samples, PNA probe based real-time PCR (Patio DEP Detection Kit; SeaSun Biomaterials, Korea) assay was performed. PNA probe was designed to hybridize to similar sequences located on different segments of target chromosomes (21, 18, and 13) and a reference chromosome. Amplification of target sequences and melting curve analysis was performed. When analyzing the melting curve, the ratio of the peak height of the target and reference chromosome was calculated and determined as aneuploidy if the ratio of peak height was abnormal. All the results from the PNA probe-based real-time PCR and melting curve analyses were compared to those from conventional karyotyping. Forty-two cases with common aneuploidies (24 of trisomy 21, 12 of trisomy 18, and 6 of trisomy 13) and 131 cases with normal karyotype were analyzed. When comparing the karyotyping results, the sensitivity and specificity of the PNA probe-based real-time PCR assay were both 100%. The level of agreement was almost perfect (k = 1.00). PNA real-time PCR assay is a rapid and easy method for detecting common aneuploidies.

Virus Genes ◽  
2022 ◽  
Jitendra K. Biswal ◽  
Biswa Ranjan Jena ◽  
Syed Zeeshan Ali ◽  
Rajeev Ranjan ◽  
Jajati K. Mohapatra ◽  

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