• Korean Journal of Veterinary Research
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• v.60 no.3
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• pp.109-116
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• 2020

This study aimed to develop a semi-nested polymerase chain reaction assay for the direct detection of Mycoplasma synoviae (M. synoviae) from clinical samples using three newly designed oligonucleotide primers specific to the variable lipoprotein haemagglutinin (vlhA) gene and differentiate M. synoviae field strains based on a nucleotide deletion or the insertion of the proline-rich repeat (PRR) region of the vlhA gene. The developed semi-nested polymerase chain reaction (PCR) assay revealed positive results in 12 out of 100 clinical samples collected from chickens showing lameness and joint swelling. Six positive samples were selected randomly for sequencing, and sequence analysis revealed 96.3-100% nucleotide identities compared to the reference sequences. Phylogenetic analysis showed that sequences of the strains in this study were closely related to WVU1853 (Spain), CK.MS.UDL.PK.2014.2 (Pakistan), and F10-2AS (USA) strains, but they were distinct from the M. synoviae-H vaccine strain sequence. M. synoviae obtained from these samples were identified as types A and C with a length of 38 and 32 amino acids, respectively. These results indicated that the specific and sensitive semi-nested PCR could be a useful diagnostic tool for the direct identification of clinical samples, and the sequence analysis of the partial vlhA gene can be useful for typing M. Synoviae.

• Molecules and Cells
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• v.24 no.3
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• pp.329-337
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• 2007

An enrichment semi-nested PCR procedure was developed for detection of Clostridium botulinum types A, B, E, and F. It was applied to sediment samples to examine the prevalence of C. botulinum in the Korean environment. The first pair of primers for the semi-nested PCR was designed using a region shared by the types A, B, E, and F neurotoxin gene sequences, and the second round employed four nested primers complementary to the BoNT/A, /B, /E, and /F encoding genes for simultaneous detection of the four serotypes. Positive results were obtained from the PCR analysis of five of 44 sediments (11%) collected from Yeong-am Lake in Korea; all were identified as deriving from type B neurotoxin (bontb) genes. Two of the C. botulinum type B organisms were isolated, and their bontb genes sequenced. The deduced amino acid sequences of BoNT/B showed 99.5 and 99.8% identity with the amino acid sequence of accession no. AB084152. Our data suggest that semi-nested PCR is a useful tool for detecting C. botulinum in sediments, and renders it practicable to conduct environmental surveys.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.3
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• pp.179-188
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• 2007

Objectives: Many neurological diseases are known to be caused by expansion of trinucleotide repeats (TNRs). It is hard to diagnose the alteration of TNRs with single cell level for preimplantation genetic diagnosis (PGD). In this study, we describe methods optimized for PGD of TNRs related diseases such as Huntington's disease (HD), spinocerebellar ataxia 3 (SCA3) and fragile X syndrome (FXS). Methods: We performed the preclinical assays with heterozygous patient's lymphocytes by single cell PCR strategy. Fluorescent semi-nested PCR and fragment analysis using automatic genetic analyzer were applied for HD and SCA 3. Whole genome amplification with multiple displacement amplification (MDA) method and fluorescent PCR were carried out for FXS. Amplification and allele drop-out (ADO) rate were evaluated in each case. Results: The fluorescent semi-nested PCR of single lymphocyte showed 100.0% of amplification and 14.0% of ADO rate in HD, and 94.7% of amplification and 5.6% of ADO rate in SCA3, respectively. We could not detect the PCR product of CGG repeats in FXS using the fluorescent semi-nested PCR alone. After applying the MDA method in FXS, 84.2% of amplification and 31.3% of ADO rate were achieved. Conclusions: Fluorescent semi-nested PCR is a reliable method for PGD of HD and SCA3. The advanced MDA method overcomes the problem of amplification failure in CGG repeats of FXS case. Optimization of methods for single cell analysis could improve the sensitivity and reliability of PGD for complicated single gene disorders of TNRs.

• Journal of Animal Science and Technology
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• v.47 no.3
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• pp.465-474
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• 2005

A two-step broad-range PCR method detecting gram-negative bacteria at the level as low as 2 CFU was developed by using primers of GNFI and GNRI and then semi-nested primer of GNF2 and GNRI. The nucleotide sequences of the primers were determined based on l6S rRNA gene. The DNA fragments of 1173 bp and 169 bp were amplified in one-step PCRs with primer sets of GNFI-GNRI and GNF2-GNRl, respectively, using template DNA from seven strains of gram-negative bacteria including Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas spp., and Acinetobacter baumaii but not from Achromobacter lyticus, Alca/igens faecalis, and five strains of gram-positive bacteria. DNA fragments of 180 bp were amplified from LTLT-pasteurized milk and UHf-pasteurized milk in the two-step PCR. The DNA fragments were amplified from LTLT-pasteurized milk which was added with Pseudomonas j/uorescens and subsequently heated at 65 $^{\circ}C$, 80 $^{\circ}C$, and 100 $^{\circ}C$ for 30 min but they were not amplified from the milk autoclaved at 121$^{\circ}C$ for 15 min. It was suggested in PCR that Pseudomonas fluorescens heated at 65 $^{\circ}C$ for 30 min in milk was more sensitive to DNase treatment than viable bacteria.

• Biomedical Science Letters
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• v.25 no.4
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• pp.331-338
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• 2019

Human Aichivirus A1 (HuAiV-A1) is a waterborne human pathogenic virus classified as Picornaviridae and Kobuvirus. In this study, we developed a method that can detect about 35 minutes faster with the same detection sensitivity level than the previously reported HuAiV-A1 diagnostic RT-PCR primer. The RT-PCR primer sets developed in this study are capable of detecting HuAiV-A1 at a level of about 100 ag and formed 563 bp amplification product. In addition, the RT-nested PCR method was able to amplify 410 bp using the RT-PCR product as a template. The detection sensitivity of our method was 10 times higher than the method with the highest detection sensitivity to date. Therefore, the detection method of HuAiV-A1 developed in this study is expected to be used in the water environment in which a small amount of virus exists. Also, this detection method is expected to be used as HuAiV-A1 diagnostic technology in both clinical and non-clinical field.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.25-32
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• 2018

Molecular techniques have been introduced for malaria diagnosis because they offer greater sensitivity and specificity than microscopic examinations. Therefore, DNA isolation methods have been developed for easy preparation and cost effectiveness. The present study described a simple protocol for Plasmodium DNA isolation from EDTA-whole blood. This study demonstrated that after heating infected blood samples with Tris-EDTA buffer and proteinase K solution, without isolation and purification steps, the supernatant can be used as a DNA template for amplification by PCR. The sensitivity of the extracted DNA of Plasmodium falciparum and Plasmodium vivax was separately analyzed by both PCR and semi-nested PCR (Sn-PCR). The results revealed that for PCR the limit of detection was $40parasites/{\mu}l$ for P. falciparum and $35.2parasites/{\mu}l$ for P. vivax, whereas for Sn-PCR the limit of detection was $1.6parasites/{\mu}l$ for P. falciparum and $1.4parasites/{\mu}l$ for P. vivax. This new method was then verified by DNA extraction of whole blood from 11 asymptomatic Myanmar migrant workers and analyzed by Sn-PCR. The results revealed that DNA can be extracted from all samples, and there were 2 positive samples for Plasmodium (P. falciparum and P. vivax). Therefore, the protocol can be an alternative method for DNA extraction in laboratories with limited resources and a lack of trained technicians for malaria diagnosis. In addition, this protocol can be applied for subclinical cases, and this will be helpful for epidemiology and control.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.123-131
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• 2017

Norovirus causes frequent epidemic viral gastroenteritis in Korea. The team for the control of noroviral foodborne outbreaks (NOROTECL) executed a project to trace the cause of norovirus contamination in agricultural products and environmental samples to reduce norovirus outbreaks in Korea. Between January and November in 2015, the contaminations by norovirus and indicator microorganisms such as coliforms, Escherichia coil and male specific coliphage (MSC) were examined in 80 agricultural products, 80 soil samples, 78 human feces samples, 3 animal feces samples, 80 agricultural water samples and 80 river water samples. Semi-nested PCR and DNA sequencing revealed 18 genogroup I and 3 genogroup II noroviruses in a total of 18 samples. These noroviruses were validated by real-time (RT)-PCR analysis. For indicator microorganisms, coliform and E. coli were respectively detected in agricultural products (68, 1%), soils (88, 7%), human feces (44, 12.8%), animal feces (67, 67%), agricultural waters (74, 30%) and river waters (96, 51%). The MSC results revealed 14 positive samples.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.235-241
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• 2023

Noroviruses are a major cause of gastroenteritis in humans and animals worldwide. In 2021, canine norovirus (CNoV) infection was detected at an animal clinic in Gwangju area, South Korea. A semi-nested polymerase chain reaction was developed to amplify a 478 bp fragment of the RdRp gene of CNoV. The phylogenetic analysis of this fragment confirmed the strain to be genogroup IV.2 (Dog/GIV.2/gw/s377/2021/KOR), which exhibited the highest similarity to the feline NoV strain GIV.2/CU081210E/USA/2010 (accession no. NC_045762) with 95.1% nucleotide (nt) identity and 98.7% amino acid (aa) identity. These research findings indicate that the detected norovirus in dogs is genetically similar to a feline-origin norovirus, suggesting easy cross-species transmission among animals.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.407-412
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• 2009

In this study, a rapid and efficient concentrating procedure that can be used for detecting viruses in vegetables was developed. The Sabin strain of poliovirus type 1 was used to evaluate the efficiency of virus recovery. The procedure included: (a) elution with 0.25 M threonine-0.3 M NaCl pH 9.5; (b) polyethylene glycol (PEG) 8000 precipitation; (c) chloroform extraction; (d) 2$^{nd}$ PEG precipitation; (f) RNA extraction; (g) reverse transcription-polymerase chain reaction (RT-PCR) combined with semi-nested PCR. The overall recoveries by elution/concentration were 29.0% from cabbage and 13.7% from lettuce. The whole procedure usually takes 18 hr. The overall detection sensitivity was 100 RT-PCR units of genogroup II norovirus (GII NoV)/25 g cabbage and 100 RT-PCR units of GII NoV/10 g lettuce. The virus detecting method developed in this study should facilitate the detection of low levels of NoV in cabbage and lettuce.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1150-1154
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• 2009

Low levels of virus contamination and naturally occurring reverse transcription-polymerase chain reaction (RT-PCR) inhibitors restrain virus detection in oysters. A rapid and efficient oyster-processing procedure that can be used for sensitive virus detection in oysters was developed. Poliovirus type 1 Sabin strain was used to evaluate the efficacy of virus recovery. The procedure included (a) acid-adsorption and elution with buffers (0.25M glycine-0.14 M NaCl, pH 7.5; 0.25M threonine-0.14M NaCl, pH 7.5); (b) polyethylene glycol (PEG) precipitation; (c) resuspension in Tween 80/Tris solution and chloroform extraction; (d) the second PEG precipitation; (e) viral RNA extraction with TRIzol and isopropanol precipitation; and (f) RT-PCR combined with semi-nested PCR. The overall recovery of elution/concentration was 19.5% with poliovirus. The whole procedure usually takes 19 hr. The overall detection sensitivity was 4 RT-PCR units of genogroup I norovirus (NoV) and 6.4 RT-PCR units of genogroup II Nov/25 g of oysters initially seeded. The virus-detecting method developed in this study should facilitate the detection of low levels of NoV in oysters.