BACKGROUND AND OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the causative agent of COVID-19 has significantly challenged the public health landscape in late 2019. After almost 3 years of the first ever SARS-CoV-2 case, the World Health Organization (WHO) declared the end of this global health emergency in May 2023. Although, despite the subsequent drop of COVID-19 cases, the SARS-CoV-2 infection still exhibited multiple waves of infection, primarily attributed to the appearance of new variants. Five of these variants have been classified as Variants of Concern (VOC): Alpha, Beta, Gamma, Delta, and the most recent, Omicron. Therefore, the development of methods for the timely and accurate detection of viral variants remains fundamental, ensuring an ongoing and effective response to the disease. This study aims to evaluate the feasibility of the application of an in-house approach in genomic surveillance for the detection of SARS-CoV-2 variants using in silico designed primers.

METHODS

The primers used for the study were particularly designed based on conserved regions of certain genes in the virus, targeting distinct mutations found in known variants of SARS-CoV-2. Viral RNA extracts from nasopharyngeal samples (n=14) were subjected to quantitative and qualitative tests (Nanodrop and AGE). Selected samples were then analyzed by RT-PCR and amplicons were submitted for sequencing. Sequence alignment analysis was carried out to identify the prevailing COVID-19 variant present in the sample population.

RESULTS

The study findings demonstrated that the in-house method was able to successfully amplify conserved sequences (spike, envelope, membrane, ORF1ab) and enabled identification of the circulating SARS-CoV-2 variant among the samples. Majority of the samples were identified as Omicron variant. Three out of four designed primers effectively bound into the conserved sequence of target genes present in the sample, revealing the specific SARSCoV-2 variant. The detected mutations characterized for Omicron found in the identified lineages included K417N, S477N, and P681H which were also identified as mutations of interest. Furthermore, identification of the B.1.448 lineage which was not classified in any known variant also provided the potential of the developed in-house method in detecting unknown variants of COVID-19.

CONCLUSION

Among the five VOCs, Omicron is the most prevalent and dominant variant. The in-house direct PCR product sequencing surveillance (DPPSS) method provided an alternative platform for SAR-CoV-2 variant analysis which is accessible and affordable than the conventional diagnostic surveillance methods and the whole genome sequencing. Further evaluation and improvements on the oligonucleotide primers may offer significant contribution to the development of a specific and direct PCRbased detection of new emerging COVID-19 variants.

Sars-cov-2 ; Polymerase Chain Reaction ; Dna Primers ; Oligonucleotide Primers ; Computer Simulation ; Conserved Sequence ; Coronavirus ; Covid-19 ; Disease ; Emergencies ; Evaluation Studies As Topic ; Genes ; Genome ; Global Health ; Health ; Identification (psychology) ; Infection ; Infections ; Membranes ; Methods ; Mutation ; Oligonucleotides ; Organizations ; Population ; Public Health ; Rna ; Rna, Viral ; Sars Virus ; Sequence Alignment ; Severe Acute Respiratory Syndrome ; Syndrome ; Viruses ; Whole Genome Sequencing ; World Health Organization

BACKGROUND

Convalescent plasma therapy (CPT) has been utilized as an emergency and last-resort treatment for viral infections, particularly in the absence of vaccine. During the COVID-19 pandemic, CPT was implemented worldwide based on its potential to provide passive immunity through SARS-CoV-2 antibodies. While numerous studies explored the effectiveness of CPT to cure COVID-19 patients, there has no research specifically focused on superiority of CPT impact on the length of hospitalization.

OBJECTIVE

This study aimed to evaluate the effect of CPT on the length of hospital stay among patients with moderate COVID-19.

METHODS

This is a single blind randomized controlled trial (RCT) study involved 30 moderate-grade COVID-19 patients age 18-75 years with positive PCR result treated at Unggul Karsa Medika Hospital Bandung from February 2 to May 31, 2022. Moderate-grade COVID-19 defined by clinical pneumonia symptoms based on World Health Organization (WHO) criteria. Eligible patients were randomly assigned (1:1 ratio) and outcome assessors were blinded, while care providers and patients were not due to the intervention nature. The intervention arm (n=15) received 200 ml of high-titer CPT within 24 hours of admission with standard care and the control arm (n=15) received standard care only. The primary outcome measured was the length of stay (LOS) in both the Emergency Room (ER) and COVID-19 High Care Unit (HCU). Data were analyzed using independent T-tests.

RESULTS

Thirty (30) eligible patients (mean age 40 years; 53% female) were analyzed for the primary outcome and all completed follow-ups. The CPT group had significantly shorter LOS than controls (mean difference for ER:-32.7 hours [95% CI:-45.0,-20.4]; HCU:-33.3 hours [95% CI:- 45.8,-20.8]; p

CONCLUSION

The administration of CPT may reduce the LOS in moderate COVID-19 patients. However, the small sample size can limit the generalizability of this result and larger sample studies are needed to strengthen this finding. Early CPT implementation may improve patient management and optimize healthcare resource utilization during the pandemic.

Pandemics ; Polymerase Chain Reaction ; Randomized Controlled Trial ; Emergency Service, Hospital ; Hospitalization ; Emergencies ; Covid-19 ; Length Of Stay ; Antibodies

BACKGROUND

The COVID-19 pandemic caused by SARS-CoV-2 significantly strained healthcare systems in the Philippines, highlighting the critical importance of reliable molecular diagnostics and genomic surveillance. Although vaccination efforts and public health measures mitigated disease impact, the continued emergence of viral variants underscores the need for sustainable local surveillance strategies. Strengthening in-country capacity through the development of in silico–designed primers and cost-effective sequencing approaches can enhance rapid variant detection and improve preparedness for future emerging infectious diseases.

OBJECTIVE

This paper offers a method in detecting the SARS-CoV-2 virus and its variants. A direct PCR product sequencing surveillance or DPPSS offers a new possibility of detecting emerging disease by using PCR products and using it as templates in determining the base sequence.

METHODOLOGY

A total of 20 random positive samples for SARS-COV-2 from March 2022 sample pool in Metro Manila, Philippines was used in this study. The RNA was extracted using Purelink™ RNA Mini Kit, quantified with NanoDrop, and subjected to one-step RT-PCR. An in-house designed in silico primers were used in this study by using thermodynamic parameters to optimize specificity and amplification efficiency, considering GC contents, balanced Tm, minimal secondary structures and cross-dimers and in silico validation via Basic Local Alignment Search Tool (BLAST) against reference databases.

Amplicons were analyzed through gel electrophoresis, sequenced, and analyzed using BioEdit software. A nucleotide BLAST search identified COVID-19 variants, confirmed using Cov-Lineages website.

RESULTS

In silico designed primers (S1, S2, E/M, Orf1ab) collectively exhibited 100% sensitivity in detecting SARS-CoV2 in nasopharyngeal swab samples. Individual primer sensitivities varied, with Orf1ab at 58.82% and E/M at 90.91%. Our analysis revealed the prevalence of Omicron sublineage BA.2 in the Philippines, aligning with local data showing more BA.2 cases than the global predominance of BA.1.

CONCLUSION

Combined in silico primers (S1, S2, E/M, ORF1ab) accurately detect SARS-COV-2 and its variants. This method provides a valuable diagnostic and surveillance tool for public health management.

Covid-19 ; Polymerase Chain Reaction ; Molecular Diagnostic Techniques

Human ; Bacteria ; Antimicrobial Stewardship ; Insemination, Artificial, Heterologous ; Multiplex Polymerase Chain Reaction ; Polymerase Chain Reaction

OBJECTIVE: To detect the expression level of T-complex polypeptide 1 (TCP1) in the bone marrow of newly diagnosed acute myeloid leukemia (AML) patients, and explore its correlation with clinical characteristics and prognosis. METHODS: The bone marrow samples from 80 newly diagnosed AML patients and 30 iron deficiency anemia (IDA) patients were collected, and real time fluorescence quantitative PCR was used to detect the expression level of TCP1 . The clinical data of AML patients were collected, and the correlation of TCP1 expression with clinical characteristics and prognosis of patients were analyzed. The impact of TCP1 on overall survival (OS) of AML patients was identified by using Kaplan-Meier curve analysis. Cox regression analysis was used to identify the factors affecting prognosis of AML patients. RESULTS: Compared with IDA patients, the expression of TCP1 was significantly increased in AML patients (P < 0.01). The high expression group of TCP1 showed a higher proportion of patients with ≥60 years and non-remission after treatment, more accompanied by TET2 mutation and poor prognosis but shorter OS compared to the low expression group (all P < 0.05). The results of multivariate Cox regression analysis showed that age, chromosomal abnormalities, therapeutic efficacy and TCP1 expression were independent risk factors affecting prognosis of AML patients (all P < 0.05). CONCLUSION TCP1 is significantly upregulated in AML patients, and its expression is associated with partial clinical features and poor prognosis. It can serve as a prognostic indicator and potential therapeutic target for AML patients.
Gene Expression Regulation, Leukemic ; Leukemia, Myeloid, Acute/metabolism* ; Humans ; Gene Expression Profiling ; Bone Marrow/metabolism* ; Anemia, Iron-Deficiency/metabolism* ; Polymerase Chain Reaction ; Prognosis ; Kaplan-Meier Estimate ; Proportional Hazards Models ; Multivariate Analysis ; Risk Factors ; Chaperonin Containing TCP-1

OBJECTIVE: To analyze the RHD genotyping and sequencing results of RhD serology negative samples in the clinic, and to further explore the laboratory methods for RhD detection, in order to provide a basis for clinical precision blood transfusion. METHODS: A total of 27 200 whole blood samples were screened for RhD blood group antigen using microcolumn gel card method.Serologic RhD-negative confirmation tests were performed on blood samples that were negative for RhD on initial screening using three different clonal strains of IgG anti-D reagents. The 10 exons of the RHD gene on chromosome 1 were also analyzed by PCR-SSP to determine RHD genotyping.When the PCR-SSP method did not yield definitive results, the RHD gene of the sample was analyzed by the third-generation sequencing. RESULTS: The results of the initial screening test by the microcolumn gel card method showed that 136 of the 27 200 samples were RhD-negative, of which 86 underwent RhD-negative confirmation testing and RHD genotyping, 88.37% (76/86 cases) of the RhD-negative confirmation test results were negative for the three anti-D reagents, and the results of RHD genotyping showed that 67.44% (58/86 cases) of the cases had a complete deletion of 10 exons, and the remaining 28 cases were RHD*711delC (1 case), RHD*D-CE(1-9)-D (1 case), RHD*D-CE(2-9-)D (2 cases), RHD*D-CE(3-9)-D (4 cases), RHD*DEL1 (c.1227G >A) mutation (16 cases), RHD*weak partial 15(845G >A) mutation (3 cases), and a mutation of c.165C >T base was found in 1 sample by three-generation sequencing. CONCLUSION RHD genotype testing of samples that are serologically negative for RhD antigen shows that some of the samples have RHD gene variants, not all of which are total deletions of RHD, suggesting that there are some limitations of the serologic method for RhD detection. Due to the polymorphism of the RHD gene structure, different RhD variants present different serologic features, which need to be further detected in combination with molecular biology testing, especially for the identification of Asian-type DELs, which is important for clinical precision blood transfusion.
Humans ; Rh-Hr Blood-Group System/genetics* ; Genotype ; Polymerase Chain Reaction ; Exons ; Blood Grouping and Crossmatching

OBJECTIVE: To establish a genotyping method for Diego, MNS and Kell blood groups based on quantitative real-time PCR (qPCR) technology, and preliminarily apply it to the screening of rare blood groups in blood donors. METHODS: Blood group gene standards containing heterozygous and homozygous alleles were prepared by blood group serological and PCR-SBT methods. Specific amplification primers and hybridization probes were designed, and explore to establish the qPCR method for detecting Diego, MNS, and Kell blood group genotypes. Then the established qPCR method was used to identify blood group genotypes of 186 blood donor samples. RESULTS: A method based on qPCR technology was established to identify Dia/Dib, S/s and K/k blood group antigens. The genotyping results of the gene standard samples were consistent with the serological testing results and genotypes detected by PCR-SBT. qPCR testing of 186 samples identified 11 cases of DI*A/B heterozygosity and 19 cases of GYPB*S/s heterozygosity, and the rest were DI*B/B, GYPB*s/s, KEL*02/02 homozygosity. No rare blood group genotypes of DI*A/A, GYPB*S/S, KEL*01.01/01.01 were found. CONCLUSION The established qPCR method is suitable for genotyping on Diego, MNS and Kell blood group, and it can be used for batch screening of blood donors and the establishment of rare blood group bank.
Humans ; Genotype ; Genotyping Techniques/methods* ; Real-Time Polymerase Chain Reaction/methods* ; Blood Group Antigens/genetics* ; Kell Blood-Group System/genetics* ; Blood Donors ; Blood Grouping and Crossmatching/methods* ; Erythrocytes ; MNSs Blood-Group System/genetics*

Point-of-care testing (POCT), as an emerging diagnostic technology, is gradually becoming an important part of the clinical diagnostic field due to its advantages, such as ease of operation, rapid response, and portability. This paper primarily introduces two mainstream technologies in POCT: lateral flow assays and nucleic acid amplification. It covers the basic principles, applications, and quality control points in design and development of the two mainstream technologies, aiming to provide a technical reference for device manufacturers, researchers, and regulatory agencies.
Point-of-Care Testing ; Point-of-Care Systems ; Quality Control ; Equipment Design ; Nucleic Acid Amplification Techniques ; Humans

From the perspective of performance evaluation, this paper describes briefly the concerns of study on each component module and the entire instrument, clinical items, software, and product testing on droplet digital PCR instruments, including the study methods and quality control requirements. The increase of the research and development efficiency of products and contribute to the promotion of application of digital PCR instruments in clinical laboratories are expected.
Polymerase Chain Reaction/methods* ; Quality Control ; Software ; Humans

OBJECTIVES: To detect prfA and hly toxin genes of Listeria monocytogenes using polymerase chain reaction (PCR) and colloidal gold technology. METHODS: L. monocytogenes DNA was extracted by boiling method. With prfA and hly of L. monocytogenes as the target genes, the 5' ends of upstream and downstream primers of prfA gene were labeled with 6-FAM and biotin, and the 5' ends of upstream and downstream primers of hly gene were labeled with digoxin and biotin, respectively, to establish the toxin gene detection method. Using cloning transformation, sequencing analysis, cloning of positive control products, the detection kid was developed and its specificity, sensitivity, reproducibility and stability were tested, followed by verification with sample testing. RESULTS: The concentration of L. monocytogenes DNA extracted by boiling method was 148.81±0.97 ng/μL, and the A₂₆₀/A₂₈₀ ratio ranged from 1.8 to 2.0. The PCR products showed a 100% homology with the gene sequences in GenBank database after cloning, transformation and sequencing. The colloidal gold strip yielded positive results only for L. monocytogenes samples without cross-reactions with Staphylococcus aureus, Escherichia coli or Bacillus cereus, and its minimum detection limit was 10^-2 ng/μL, demonstrating a 10-fold greater sensitivity of the test than agarose gel electrophoresis. The test also showed good reproducibility of the results when performed by different operators with good stability of the test strips after storage for 6 to 12 months. The test results showed that this kit could accurately and quickly detect L.monocytogenes in the test samples. CONCLUSIONS The detection kit developed in this study can simultaneously detect prfA and hly toxin genes of L. monocytogenes with good specificity, sensitivity, reproducibility and stability for use in food safety inspection.
Listeria monocytogenes/isolation & purification* ; Gold Colloid ; Bacterial Toxins/genetics* ; Polymerase Chain Reaction/methods* ; Hemolysin Proteins/genetics* ; Bacterial Proteins/genetics* ; DNA, Bacterial/genetics* ; Food Microbiology ; Heat-Shock Proteins