Displaying publications 21 - 40 of 1868 in total

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  1. Sharko F, Rbbani G, Siriyappagouder P, Raeymaekers JAM, Galindo-Villegas J, Nedoluzhko A, et al.
    BMC Bioinformatics, 2023 May 19;24(1):205.
    PMID: 37208611 DOI: 10.1186/s12859-023-05331-y
    BACKGROUND: Circular RNAs (circRNAs) are covalently closed-loop RNAs with critical regulatory roles in cells. Tens of thousands of circRNAs have been unveiled due to the recent advances in high throughput RNA sequencing technologies and bioinformatic tools development. At the same time, polymerase chain reaction (PCR) cross-validation for circRNAs predicted by bioinformatic tools remains an essential part of any circRNA study before publication.

    RESULTS: Here, we present the CircPrime web-based platform, providing a user-friendly solution for DNA primer design and thermocycling conditions for circRNA identification with routine PCR methods.

    CONCLUSIONS: User-friendly CircPrime web platform ( http://circprime.elgene.net/ ) works with outputs of the most popular bioinformatic predictors of circRNAs to design specific circular RNA primers. CircPrime works with circRNA coordinates and any reference genome from the National Center for Biotechnology Information database).

    Matched MeSH terms: Polymerase Chain Reaction
  2. Teh KJ, Tang HY, Lim LS, Pung HS, Gan SY, Lai NS
    Eur Rev Med Pharmacol Sci, 2023 May;27(10):4378-4385.
    PMID: 37259718 DOI: 10.26355/eurrev_202305_32443
    Lyme borreliosis is caused by the Gram-negative spirochetes Borrelia spp., particularly Borrelia burgdorferi sensu lato complex. The disease is transmitted through the bite of the infected black-legged Ixodes tick. Lyme borreliosis extensively occurs in the Northern Hemisphere, mainly in the United States. Lyme borreliosis cases are also detected in Asian countries including Korea, Nepal, China, Taiwan, and Japan. However, there is an inadequate understanding of Lyme borreliosis in the Southeast Asian region. Hence, this review aims to provide a brief update on the prevalence of Lyme borreliosis infection in Southeast Asia based on the latest literature on this issue. Lyme borreliosis has been discovered in human serum in Indonesia, Malaysia, and Singapore. The human serum samples were mainly examined with ELISA test using Borrelia spp. IgG and IgM antigens. Borrelia spp. also has been detected in ticks found on host animals such as Sundamys muelleri and Python in Malaysia, Thailand, and Laos. Polymerase chain reaction (PCR) is used to detect the presence of Borrelia DNAs in the samples. The published studies have demonstrated that Borrelia spp. exists in Southeast Asia and although the incidence is relatively low, it is believed that Lyme disease cases are under-reported.
    Matched MeSH terms: Polymerase Chain Reaction/methods
  3. Meng X, Wen K, Citartan M, Lin Q
    Analyst, 2023 Feb 13;148(4):787-798.
    PMID: 36688616 DOI: 10.1039/d2an01767a
    Aptamers are single-stranded oligonucleotide molecules that bind with high affinity and specificity to a wide range of target molecules. The method of systematic evolution of ligands by exponential enrichment (SELEX) plays an essential role in the isolation of aptamers from a randomized oligonucleotide library. To date, significant modifications and improvements of the SELEX process have been achieved, engendering various forms of SELEX from conventional SELEX to microfluidics-based full-chip SELEX. While full-chip SELEX is generally considered advantageous over conventional SELEX, there has not yet been a conclusive comparison between the methods. Herein, we present a comparative study of three SELEX strategies for aptamer isolation, including those using conventional agarose bead-based partitioning, microfluidic affinity selection, and fully integrated microfluidic affinity selection and PCR amplification. Using immunoglobulin E (IgE) as a model target molecule, we compare these strategies in terms of the time and cost for each step of the SELEX process including affinity selection, amplification, and oligonucleotide conditioning. Target-binding oligonucleotides in the enriched pools are sequenced and compared to assess the relative efficacy of the SELEX strategies. We show that the microfluidic strategies are more time- and cost-efficient than conventional SELEX.
    Matched MeSH terms: Polymerase Chain Reaction
  4. Ramli NM, Bae YJ
    Neuroimaging Clin N Am, 2023 Feb;33(1):43-56.
    PMID: 36404046 DOI: 10.1016/j.nic.2022.07.002
    MR imaging is essential in diagnosing viral encephalitis. Clinical features, cerebrospinal fluid analysis and pathogen confirmation by polymerase chain reaction can be supported by assessing imaging features. MR imaging patterns with typical locations can identify pathogens such as temporal lobe for herpes simplex virus type 1; bilateral thalami for Japanese encephalitis and influenza virus ; and brainstem for enterovirus and rabies. In this article, we have reviewed representative viral encephalitis and its MR imaging patterns. In addition, we also presented acute viral encephalitis without typical MR imaging patterns, such as dengue and varicella-zoster virus encephalitis.
    Matched MeSH terms: Polymerase Chain Reaction
  5. Nik Zuraina NMN, Mohamad S, Hasan H, Goni MD, Suraiya S
    Pathog Glob Health, 2023 Feb;117(1):63-75.
    PMID: 35331083 DOI: 10.1080/20477724.2022.2028378
    Respiratory tract infections (RTIs), including pneumonia and pulmonary tuberculosis, are among the leading causes of death worldwide. The use of accurate diagnostic tests is crucial to initiate proper treatment and therapy to reduce the mortality rates for RTIs. A PCR assay for simultaneous detection of six respiratory bacteria: Haemophilus influenzae, Klebsiella pneumoniae, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae, was developed in our lab. The current study aimed to evaluate the performance of this assay along with the retrospective surveillance of respiratory pathogens at a teaching hospital in Kelantan, Malaysia. Leftover sputa (n = 200) from clinical laboratories were collected and undergone DNA template preparation for PCR analysis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the PCR assay were determined in comparison with the gold standard sputum culture. Overall, the accuracy performance of this assay was 94.67% (95% CI: 90.87% to 97.21%) with sensitivity, specificity, PPV and NPV of 100%, 91.67%, 87.1% and 100%, respectively. Based on the organisms detected from sputa, K. pneumoniae ranked as the top isolate (n = 48), followed by P. aeruginosa (n = 13) and H. influenzae (n = 10). Surveillance among the patients showed that the associations of bacterial positive with gender and means of acquisition were found significant (p values = 0.049 and 0.001, respectively). Besides the promising performance of this ready-to-use molecular-based assay for the rapid detection of selected bacteria pathogens, this study also highlighted significant spread of K. pneumoniae RTIs in the community.
    Matched MeSH terms: Multiplex Polymerase Chain Reaction*
  6. Shaaban SI, Talat D, Khatab SA, Nossair MA, Ayoub MA, Ewida RM, et al.
    BMC Vet Res, 2023 Jan 21;19(1):16.
    PMID: 36670434 DOI: 10.1186/s12917-023-03572-w
    BACKGROUND: Helicobacter pylori is one of the most common bacterial infections and is widespread globally. It causes a variety of gastrointestinal disorders, though a great proportion of infections are asymptomatic. A total of 143 fresh stool samples were collected from apparently healthy farm and pet animals (43 cattle, 50 buffaloes, 50 sheep, 50 dogs, and 50 cats), in addition to 768 human stool samples. The samples were examined using stool antigen and rapid antibody tests, and further confirmation of glmM "human antigen-positive samples and animal milk samples" was conducted by polymerase chain reaction (PCR).

    RESULTS: The prevalence rates of H. pylori infection in animals were 22.2% and 16% in antibody and stool antigen tests, respectively. The detection rates were 28%, 24%, 12%, 10%, and 4.7% in cats, dogs, buffaloes, sheep, and cattle, respectively. On the other hand, the prevalence rate of H. pylori infection in human stool samples was 74.8%, and a statistically significant association was observed between prevalence and several factors, such as sex, age, and locality. PCR was performed to detect the glmM gene of H. pylori, and this gene was found in 21 of 27 human antigen-positive samples and 5 of 13 animal milk samples.

    CONCLUSIONS: H. pylori was detected in both human and animal samples. Furthermore, glmM was found in milk and human samples. Our findings suggest that pet and farm animals could transmit H. pylori infection to humans.

    Matched MeSH terms: Polymerase Chain Reaction/veterinary
  7. Alishaq M, Al Ajmi JA, Shaheen M, Elgendy M, Vinoy S, Thomas AG, et al.
    PLoS One, 2023;18(10):e0291989.
    PMID: 37792687 DOI: 10.1371/journal.pone.0291989
    BACKGROUND: There is debate over whether physical attendance at school affects the spread of the SARS-CoV-2 pandemic.

    METHODS: A cohort of personnel from several schools in Qatar provided nasopharyngeal swabs (NPS) for SARS-CoV-2 RT-PCR and rapid antigen testing. Each of them was monitored for infection until February 2022.

    RESULTS: In total, 3,241 employees gave samples for analysis. Prior to the start of the 2020-2021 academic year (Group I), 3.49% of samples tested positive for SARS-CoV-2. Most of the positive PCR results were from male, senior, non-teaching staff members. Only 110 (3.39%) employees who had enrolled in face-to-face instruction before the B.1.1.7 variant's emergence (Group II), 238 (7.34%) after the B.1.1.7 variant's emergence (Group III), and 410 (12.65%) after the introduction of the Omicron variant (Group IV) had reported infection by PCR test. Most people who tested positive by PCR after enrolling in school were young, female teachers. In the Cox Proportional-Hazards Model, exposure to a confirmed case, the presence of symptoms in the two weeks prior to exposure in all groups-young age in Groups II and III, male gender in Groups I and IV, shared housing in Group III, and the presence of comorbidities in Groups II and III independently predicted SARS-CoV-2 infection in school staff.

    CONCLUSION: Critical information about the risk of SARS-CoV-2 infection in school workers during the whole pandemic is provided by our study. School operations in Qatar were made safer through initial and ongoing screenings, as well as widespread vaccination of school personnel.

    Matched MeSH terms: Polymerase Chain Reaction
  8. Kee PS, Karunanathie H, Maggo SDS, Kennedy MA, Chua EW
    Methods Mol Biol, 2023;2967:181-192.
    PMID: 37608112 DOI: 10.1007/978-1-0716-3358-8_15
    Polymerase chain reaction (PCR) is a laboratory technique used to amplify a targeted region of DNA, demarcated by a set of oligonucleotide primers. Long-range PCR is a form of PCR optimized to facilitate the amplification of large fragments. Using the adapted long-range PCR protocol described in this chapter, we were able to generate PCR products of 6.6, 7.2, 13, and 20 kb from human genomic DNA samples. For some of the long PCRs, successful amplification was not possible without the use of PCR enhancers. Thus, we also evaluated the impact of some enhancers on long-range PCR and included the findings as part of this updated chapter.
    Matched MeSH terms: Polymerase Chain Reaction*
  9. Patel K, Klena J, Lo MK
    Methods Mol Biol, 2023;2682:25-31.
    PMID: 37610571 DOI: 10.1007/978-1-0716-3283-3_2
    From its discovery in Malaysia in the late 1990s, the spillover of the Nipah virus from its pteropid reservoir into the human population has resulted in sporadic outbreaks of fatal encephalitis and respiratory disease. In this chapter, we revise a previously described quantitative reverse transcription polymerase chain reaction method, which now utilizes degenerate nucleotides at certain positions in the probe and the reverse primer to accommodate the sequence heterogeneity observed within the Nipah henipavirus species.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction
  10. Rashid SA, Nazakat R, Muhamad Robat R, Ismail R, Suppiah J, Rajendran K, et al.
    Front Public Health, 2023;11:1208348.
    PMID: 37965510 DOI: 10.3389/fpubh.2023.1208348
    Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) may transmit through airborne route particularly when the aerosol particles remain in enclosed spaces with inadequate ventilation. There has been no standard recommended method of determining the virus in air due to limitations in pre-analytical and technical aspects. Furthermore, the presence of low virus loads in air samples could result in false negatives. Our study aims to explore the feasibility of detecting SARS-CoV-2 ribonucleic acid (RNA) in air samples using droplet digital polymerase chain reaction (ddPCR). Active and passive air sampling was conducted between December 2021 and February 2022 with the presence of COVID-19 confirmed cases in two hospitals and a quarantine center in Klang Valley, Malaysia. SARS-CoV-2 RNA in air was detected and quantified using ddPCR and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The comparability of two different digital PCR platforms (QX200 and QIAcuity) to RT-PCR were also investigated. Additionally negative staining transmission electron microscopy was performed to visualize virus ultrastructure. Detection rates of SARS-CoV-2 in air samples using ddPCR were higher compared to RT-PCR, which were 15.2% (22/145) and 3.4% (5/145), respectively. The sensitivity and specificity of ddPCR was 100 and 87%, respectively. After excluding 17 negative samples (50%) by both QX200 and QIAcuity, 15% samples (5/34) were found to be positive both ddPCR and dPCR. There were 23.5% (8/34) samples that were detected positive by ddPCR but negative by dPCR. In contrast, there were 11.7% (4/34) samples that were detected positive by dPCR but negative by ddPCR. The SARS-CoV-2 detection method by ddPCR is precise and has a high sensitivity for viral RNA detection. It could provide advances in determining low viral titter in air samples to reduce false negative reports, which could complement detection by RT-PCR.
    Matched MeSH terms: Real-Time Polymerase Chain Reaction/methods
  11. Khoo YW, Li S, Chong KP
    J Infect Public Health, 2022 Dec;15(12):1378-1380.
    PMID: 36356352 DOI: 10.1016/j.jiph.2022.11.002
    Matched MeSH terms: Polymerase Chain Reaction
  12. Roslan MA, Ngui R, Vythilingam I, Wan Sulaiman WY
    J Vector Ecol, 2022 Dec;47(2):142-152.
    PMID: 36314668 DOI: 10.52707/1081-1710-47.2.142
    The study assessed the distribution of Malaysian Ae. albopictus adults associated with Wolbachia detection in low-rise residential areas using a modified sticky ovitrap (MSO). The relationship between Ae. albopictus and climatological parameters were also determined. Fifty-two weeks of surveillance using 273 MSOs were conducted in four installation areas of eleven sampling sites. Specimens were subjected to PCR using wsp-specific primers for Wolbachia detection. The relationship between climatological parameters and Ae. albopictus captured were analyzed using Spearman rank correlation coefficient test. The majority of Ae. albopictus were captured in residential houses (87%), followed by playgrounds or parks (11.5%), guardhouses (1%), and community halls (0.5%). Most of the specimens (92%) were superinfected with wAlbA and wAlbB strains. A positive correlation with no significant association was found for rainfall (r = 0.015, P = 0.072), relative humidity (r = 0.005, P = 0.526), minimum temperature (r = 0.005, P = 0.516), and mean temperature (r = 0.003, P = 0.689). MSO effectively captured a high number of Ae. albopictus that was determined to be the predominant mosquito species found in low-rise residential areas. The adult collection is not only influenced by climatological parameters but also by other factors, including environmental conditions and general sanitation status.
    Matched MeSH terms: Polymerase Chain Reaction
  13. Chin KL, Teoh BT, Sam SS, Loong SK, Tan KK, Azizan NS, et al.
    Trop Biomed, 2022 Dec 01;39(4):518-523.
    PMID: 36602210 DOI: 10.47665/tb.39.4.005
    Zika virus (ZIKV) infection has emerged as a global health concern following epidemic outbreaks of severe neurological disorders reported in Pacific and Americas since 2016. Therefore, a rapid, sensitive and specific diagnostic test for ZIKV infection is critical for the appropriate patient management and the control of disease spread. A TaqMan minor groove binding (MGB) probe-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed based on the conserved sequence regions of 463 ZIKV NS2B genes. The designed ZIKV qRT-PCR assay was evaluated for its detection limit, strain coverage and cross-reactivity. We further assessed the clinical applicability of qRT-PCR assay for ZIKV RNA detection using a total 18 simulated clinical specimens. The detection limit of the qRT-PCR assay was 11.276 ZIKV RNA copies at the 95% probability level (probit analysis, p<= 0.05). Both Asian and African ZIKV strains were detected by the qRT-PCR assay without cross-reacting with DENV-1, DENV-2, DENV-3, DENV-4, CHIKV, JEV, LGTV, GETV and SINV. The qRT-PCR assay demonstrated a perfect agreement (k = 1.000, P < 0.001) with the reference assay; the sensitivity and specificity of the qRT-PCR assay were 100% (95% CI= 79.6-100) and 100% (95% CI= 43.9-100) respectively. The qRT-PCR assay developed in this study is a useful diagnostic tool for the broad coverage detection and quantification of both the Asian and African ZIKV strains.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction; Real-Time Polymerase Chain Reaction
  14. John DV, Aryalakshmi B, Deora H, Purushottam M, Raju R, Mahadevan A, et al.
    Trop Biomed, 2022 Dec 01;39(4):489-498.
    PMID: 36602206 DOI: 10.47665/tb.39.4.002
    Despite clinical suspicion of an infection, brain abscess samples are often culture-negative in routine microbiological testing. Direct PCR of such samples enables the identification of microbes that may be fastidious, non-viable, or unculturable. Brain abscess samples (n = 217) from neurosurgical patients were subjected to broad range 16S rRNA gene PCR and sequencing for bacteria. All these samples and seven formalin-fixed paraffin-embedded tissue (FFPE) samples were subjected to species-specific 18S rRNA PCR for neurotropic free-living amoeba that harbour pathogenic bacteria. The concordance between smear and/or culture and PCR was 69%. One-third of the samples were smear- and culture-negative for bacterial agents. However, 88% of these culture-negative samples showed the presence of bacterial 16S rRNA by PCR. Sanger sequencing of 27 selected samples showed anaerobic/fastidious gram negative bacteria (GNB, 38%), facultative Streptococci (35%), and aerobic GNB (27%). Targeted metagenomics sequencing of three samples showed multiple bacterial species, including anaerobic and non-culturable bacteria. One FFPE tissue revealed the presence of Acanthamoeba 18S rRNA. None of the frozen brain abscess samples tested was positive for 18S rRNA of Acanthamoeba or Balamuthia mandrillaris. The microbial 16/18S rRNA PCR and sequencing outperformed culture in detecting anaerobes, facultative Streptococci and FLA in brain abscess samples. Genetic analyses of 16S/18S sequences, either through Sanger or metagenomic sequencing, will be an essential diagnostic technology to be included for diagnosing culture-negative brain abscess samples. Characterizing the microbiome of culture-negative brain abscess samples by molecular methods could enable detection and/or treatment of the source of infection.
    Matched MeSH terms: Polymerase Chain Reaction/methods
  15. Suali L, Mohammad Salih FA, Ibrahim MY, Jeffree MSB, Thomas FM, Siew Moy F, et al.
    Hemoglobin, 2022 Nov;46(6):317-324.
    PMID: 36815306 DOI: 10.1080/03630269.2023.2169154
    β-thalassemia is a serious public health problem in Sabah due to its high prevalence. This study aimed to investigate the effects of different types of β-globin gene mutations, coinheritance with α-globin gene mutations, XmnI-Gγ, and rs368698783 polymorphisms on the β-thalassemia phenotypes in Sabahan patients. A total of 111 patients were included in this study. The sociodemographic profile of the patients was collected using a semi-structured questionnaire, while clinical data were obtained from their medical records. Gap-PCR, ARMS-PCR, RFLP-PCR, and multiplex PCR were performed to detect β- and α-globin gene mutations, as well as XmnI-Gγ and rs368698783 polymorphisms. Our data show that the high prevalence of β-thalassemia in Sabah is not due to consanguineous marriages (5.4%). A total of six different β-globin gene mutations were detected, with Filipino β°-deletion being the most dominant (87.4%). There were 77.5% homozygous β-thalassemia patients, 16.2% compound heterozygous β-thalassemia patients, and 6.3% β-thalassemia/Hb E patients. Further evaluation on compound heterozygous β-thalassemia and β-thalassemia/Hb E patients found no concomitant α-globin gene mutations and the rs368698783 polymorphism. Furthermore, the XmnI-Gγ (-/+) genotype did not demonstrate a strong impact on the disease phenotype, as only two of five patients in the compound heterozygous β-thalassemia group and two of three patients in the β-thalassemia/Hb E group had a moderate phenotype. Our findings indicate that the severity of the β-thalassemia phenotypes is closely related to the type of β-globin gene mutations but not to the XmnI-Gγ and rs368698783 polymorphisms.
    Matched MeSH terms: Multiplex Polymerase Chain Reaction
  16. Fu JYL, Chong YM, Sam IC, Chan YF
    J Virol Methods, 2022 Mar;301:114462.
    PMID: 35026305 DOI: 10.1016/j.jviromet.2022.114462
    Emerging SARS-CoV-2 variants of concern (VOC) have been associated with enhanced transmissibility and immune escape. Next-generation sequencing (NGS) of the whole genome is the gold standard for variant identification for surveillance but is time-consuming and costly. Rapid and cost-effective assays that detect SARS-CoV-2 variants are needed. We evaluated Allplex SARS-CoV-2 Master Assay and Variants I Assay to detect HV69/70 deletion, Y144 deletion, E484K, N501Y, and P681H spike mutations in 248 positive samples collected in Kuala Lumpur, Malaysia, between January and May 2021. Spike variants were detected in 78/248 (31.5 %), comprising 60 VOC B.1.351 (beta) and 18 B.1.1.7 (alpha). With NGS as reference for 115 samples, the sensitivity for detecting the spike mutations was 98.7 % with the Master Assay and 100 % with the Variants I Assay. The emergence of beta variants correlated with increasing COVID-19 infections in Malaysia. The prevalence of alpha VOC and lineage B.1.466.2 was low. These assays detect mutations present in alpha, beta and gamma VOCs. Of the VOCs which have subsequently emerged, the assays should detect omicron (B.1.1.529) but not B.1.617.2 (delta). In conclusion, spike variant PCR assays can be used to rapidly monitor selected SARS-CoV-2 VOCs in resource-limited settings, but require updates as new variants emerge.
    Matched MeSH terms: Reverse Transcriptase Polymerase Chain Reaction; Multiplex Polymerase Chain Reaction
  17. Jeyaprakasam NK, Low VL, Liew JWK, Pramasivan S, Wan-Sulaiman WY, Saeung A, et al.
    Sci Rep, 2022 01 10;12(1):354.
    PMID: 35013403 DOI: 10.1038/s41598-021-04106-w
    Blood feeding and host-seeking behaviors of a mosquito play an imperative role in determining its vectorial capacity in transmitting pathogens. Unfortunately, limited information is available regarding blood feeding behavior of Anopheles species in Malaysia. Collection of resting Anopheles mosquitoes for blood meal analysis poses a great challenge especially for forest dwelling mosquitoes. Therefore, a laboratory-based study was conducted to evaluate the potential use of mosquitoes caught using human landing catch (HLC) for blood meal analysis, and subsequently to document blood feeding behavior of local Anopheles mosquitoes in Peninsular Malaysia. The laboratory-based experiment from this study revealed that mosquitoes caught using HLC had the potential to be used for blood meal analysis. Besides HLC, mosquitoes were also collected using manual aspirator and Mosquito Magnet. Overall, 47.4% of 321 field-caught Anopheles mosquitoes belonging to six species were positive for vertebrate host DNA in their blood meal. The most frequent blood meal source was human (45.9%) followed by wild boar (27.4%), dog (15.3%) and monkey (7.5%). Interestingly, only Anopheles cracens and Anopheles introlatus (Leucosphyrus Group) fed on monkey. This study further confirmed that members of the Leucosphyrus Group are the predominant vectors for knowlesi malaria transmission in Peninsular Malaysia mainly due to their simio-anthropophagic feeding behavior.
    Matched MeSH terms: Polymerase Chain Reaction*
  18. Bonny SQ, Hossain MAM, Uddin SMK, Pulingam T, Sagadevan S, Johan MR
    Crit Rev Food Sci Nutr, 2022;62(5):1317-1335.
    PMID: 33146031 DOI: 10.1080/10408398.2020.1841728
    Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus are the most significant aquatic pathogens of the genera Vibrio, account for most Vibrio-associated outbreaks worldwide. Rapid identification of these pathogens is of great importance for disease surveillance, outbreak investigations and food safety maintenance. Traditional culture dependent methods are time-consuming and labor-intensive whereas culture-independent polymerase chain reaction (PCR) based assays are reliable, consistent, rapid and reproducible. This review covers the recent development and applications of PCR based techniques, which have accelerated advances in the analysis of nucleic acids to identify three major pathogenic vibrios. Emphasis has been given to analytical approaches as well as advantages and limits of the available methods. Overall, this review article possesses the substantial merit to be used as a reference guide for the researchers to develop improved PCR based techniques for the differential detection and quantification of Vibrio species.
    Matched MeSH terms: Polymerase Chain Reaction
  19. Othman S, Lee PY, Lam JY, Philip N, Azhari NN, Affendy NB, et al.
    PeerJ, 2022;10:e12850.
    PMID: 35291487 DOI: 10.7717/peerj.12850
    BACKGROUND: Leptospirosis is a zoonotic disease caused by bacteria of the genus Leptospira that affects both humans and animals worldwide. Early detection of the pathogen in humans is crucial for early intervention and control of the progression of the disease to a severe state. It is also vitally important to be able to detect the presence of the pathogen in carrier animals to control the spread of the disease from the environment. Here we developed a simple and rapid loop-mediated isothermal amplification (LAMP) assay targeting the leptospiral secY gene.

    RESULTS: Several reaction conditions of the LAMP reaction were optimized to ensure efficient amplification of the target DNA. The sensitivity of the developed LAMP assay obtained using a pure Leptospira culture was 2 × 104 copies of genomic DNA per reaction (equivalent to 0.1 ng) for a 40-minute reaction time. No cross-reactions were observed in the LAMP reaction against a series of non-leptospiral bacteria, indicating a specific reaction. The applicability of the LAMP assay was demonstrated on human blood and urine specimens collected from suspected leptospirosis patients and rat kidney specimens collected from suspected leptospirosis outbreak areas and high-risk areas. The developed LAMP assay demonstrated a higher detection rate for leptospiral DNA compared with the polymerase chain reaction (PCR) assay, possibly due to the presence of inhibitory substances, especially in rat kidney specimens, to which the PCR method is more susceptible. The present findings also highlight the importance of urine sample collection from patients for routine monitoring of the disease.

    CONCLUSIONS: In short, the developed LAMP assay can serve as a feasible alternative tool for the diagnosis of leptospirosis and be used for epidemiological and environmental surveillance of the disease, considering its robustness, rapidity, sensitivity, and specificity, as demonstrated in this study.

    Matched MeSH terms: Polymerase Chain Reaction
  20. Alishaq M, Jeremijenko A, Nafady-Hego H, Al Ajmi JA, Elgendy M, Thomas AG, et al.
    BMC Public Health, 2021 11 11;21(1):2070.
    PMID: 34763694 DOI: 10.1186/s12889-021-12134-4
    BACKGROUND: There is controversy regarding the role of in-person attendance in schools and transmission of the SARS-CoV-2 pandemic. Several studies have demonstrated no increase in transmission, while some have reported large outbreaks with in-person attendance. We determined the incidence and risk factors for SARS-CoV-2 infection among school staff after one school term.

    METHODS: Nasopharyngeal swabs (NPS) for SARS-CoV-2 RT-PCR and blood for SARS-CoV-2 antibody testing were obtained from staff at a large international school in Qatar at the beginning of the 2020-2021 school year and repeated at the end of the first term.

    RESULTS: A total of 376 staff provided samples for testing. At the beginning of the 2020-2021 school year, the PCR positivity for SARS-CoV-2 was 13%, while seropositivity was 30.1%. A majority of those who tested positive either by PCR or serologically, were non-teaching staff. At the end of the first school term four months later, only 3.5% of the initially antibody-negative staff had seroconverted. In multivariable logistic regression analysis, male gender (OR 11.48, 95%CI 4.77-27.64), non-teaching job category (OR 3.09, 95%CI 1.10-8.64), contact with a confirmed case (OR 20.81, 95%CI 2.90-149.18), and presence of symptoms in the preceding 2 weeks [1-2 symptoms OR 4.82, 95%CI 1.79-12.94); ≥3 symptoms OR 42.30, 95%CI 3.76-476.43) independently predicted SARS-CoV-2 infection in school staff before school starting.

    CONCLUSION: Male gender, non-teaching job, presence of symptoms, and exposure to a confirmed case were associated with higher risk of infection. These data can help policymakers in determining the optimal strategy for school reopening.

    Matched MeSH terms: Polymerase Chain Reaction
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