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1.
J Plast Reconstr Aesthet Surg ; 87: 54-60, 2023 12.
Article in English | MEDLINE | ID: mdl-37804648

ABSTRACT

Infantile hemangiomas (IHs) of the lips are associated with an increased risk of incomplete involution and ulceration, causing disfigurement. Treatment with oral propranolol (OPT) has credible efficacy but takes months to complete. Thus, this study aimed to investigate the efficacy of intralesional betamethasone injection (IBI) as an alternative treatment for protruding localized IHs of the lips. To investigate the efficacies of OPT and IBI, we designed a prospective, noninferiority, parallel-group study. The primary outcome assessed was treatment response rate. Secondary outcome assessments included lesion size changes and surgical rate. Additionally, complication rates and treatment durations of OPT and IBI were compared. The treatment response rate of IBI was not inferior to that of OPT (95.7% vs. 76.0%, respectively; a difference of 19.7%, 95% confidence interval [CI], -4.4% to 41.6%). The average surgical rate in the IBI group was significantly lower than that in the OPT group (8.7% vs. 40%, respectively; p = 0.012), and the average duration of treatment for IBI was shorter than that of OPT (2.1 months vs. 6.3 months, respectively; p < 0.001). There were no severe adverse drug events in either group. If not managed properly, small, localized lip IHs may cause disfigurement in a child. Our study demonstrated that IBI is as effective as OPT in treating protruding localized lip IHs. Moreover, IBI treatment has a shorter duration and lower surgical rate than OPT. With proper care, IBI is an effective treatment modality for small and localized lip IHs.


Subject(s)
Hemangioma , Skin Neoplasms , Child , Humans , Infant , Propranolol/adverse effects , Lip/pathology , Hemangioma/drug therapy , Betamethasone/therapeutic use , Prospective Studies , Treatment Outcome , Skin Neoplasms/drug therapy , Adrenergic beta-Antagonists/therapeutic use
2.
Ann Plast Surg ; 89(2): 214-217, 2022 08 01.
Article in English | MEDLINE | ID: mdl-35502973

ABSTRACT

BACKGROUND: Oral propranolol can effectively activate and accelerate infantile hemangioma (IH) involution; however, could the final outcome of oral propranolol treatment for IHs commensurate that of spontaneous involution? OBJECTIVE: This study aimed to investigate the long-term therapeutic effect of oral propranolol for IHs. METHODS: We present an individual matching comparative study with (1) oral propranolol therapy for mixed and deep IHs on the lips, nose, and parotid and (2) lesion type- and lesion location-matched untreated IHs as controls. Patients' follow-up photographs were assessed by 3 surgeons blinded of their treatment. Outcome measures were the quantification of the degree of sequelae ranging from 1 to 4 and the age at which IH achieved involution arrest. RESULTS: Ten groups of oral propranolol and untreated patients with matched lesions were assessed. Average age at which lesions stabilized and reached no change in appearance was 1.7 years old and 6.3 years old for propranolol group and untreated group ( t = 5.663, P < 0.001). There was no significant difference in the quantified degree of sequelae for oral propranolol group and untreated group upon follow-up (1.60 vs 1.40, respectively; t = 1.259, P = 0.240). CONCLUSIONS: Oral propranolol therapy accelerates IH involution but does not have a superior effect than spontaneous involution on the overall outcome of problematic IHs.


Subject(s)
Hemangioma, Capillary , Hemangioma , Skin Neoplasms , Administration, Oral , Adrenergic beta-Antagonists/therapeutic use , Disease Progression , Hemangioma/drug therapy , Hemangioma, Capillary/drug therapy , Humans , Infant , Propranolol/therapeutic use , Retrospective Studies , Skin Neoplasms/complications , Treatment Outcome
3.
J Virol Methods ; 259: 116-121, 2018 09.
Article in English | MEDLINE | ID: mdl-29902491

ABSTRACT

Bovine leukemia virus (BLV) is a contagious, oncogenic deltaretrovirus of cattle with a worldwide distribution. In the US, over 40% of dairy cows are infected with the virus, and evidence of its economic impact is growing. This study evaluated the performance of a field-deployable automatic nucleic acid-extraction/insulated isothermal PCR (iiPCR) system for on-site BLV-proviral DNA detection in dairy cows compared with a conventional laboratory real-time PCR (rt-PCR). Assay performance was verified in parallel tests of 36 archived blood samples with 100% agreement (κ = 1.0; n = 36) between the iiPCR and conventional rt-PCR systems, and the limit of detection of the iiPCR assay was estimated to be 4 copies (genome equivalent) per reaction. The field-deployable iiPCR system was subsequently used on-farm to test freshly collected blood samples, and showed 100% agreement (κ = 1.0; n = 32) with the laboratory rt-PCR system. Fresh blood samples were collected on a second farm and tested on both systems, also with 100% agreement (κ = 1.0; n = 34). The field-deployable iiPCR/POCKIT™ combo system performs as well as a conventional laboratory-based rt-PCR system for detection of BLV proviral DNA in whole blood and may be a useful tool for on-farm evaluation of BLV-infection status in dairy cattle.


Subject(s)
DNA, Viral/isolation & purification , Enzootic Bovine Leukosis/diagnosis , Leukemia Virus, Bovine/isolation & purification , Molecular Diagnostic Techniques/methods , Point-of-Care Testing , Polymerase Chain Reaction/methods , Proviruses/isolation & purification , Animals , Automation/methods , Cattle , DNA, Viral/genetics , Enzootic Bovine Leukosis/virology , Leukemia Virus, Bovine/genetics , Proviruses/genetics
4.
J Clin Microbiol ; 56(5)2018 05.
Article in English | MEDLINE | ID: mdl-29436418

ABSTRACT

Dengue virus (DENV) infection, a mosquito-borne disease, is a major public health problem in tropical countries. Point-of-care DENV detection with good sensitivity and specificity enables timely early diagnosis of DENV infection, facilitating effective disease management and control, particularly in regions of low resources. The Pockit dengue virus reagent set (GeneReach Biotech), a reverse transcription insulated isothermal PCR (RT-iiPCR), is available to detect all four serotypes of DENV on the field-deployable Pockit system, which is ready for on-site applications. In this study, analytical and clinical performances of the assay were evaluated. The index assay did not react with 14 non-DENV human viruses, indicating good specificity. Compared to the U.S. CDC DENV-1-4 real-time quantitative RT-PCR (qRT-PCR) assay, testing with serial dilutions of virus-spiked human sera demonstrated that the index assay had detection endpoints that were separately comparable with the 4 serotypes. Excellent reproducibility was observed among repeat tests done by six operators at three sites. In clinical performance, 195 clinical sera collected around Kaohsiung city in 2012 and 21 DENV-4-spiked sera were tested with the RT-iiPCR and qRT-PCR assays in parallel. The 121 (11 DENV-1, 78 DENV-2, 11 DENV-3, and 21 DENV-4) qRT-PCR-positive and 95 qRT-PCR-negative samples were all positive and negative by the RT-iiPCR reagent results, respectively, demonstrating high (100%) interrater agreement (95% confidence interval [CI95%], ∼98.81% to 100%; κ = 1). With analytical and clinical performance equivalent to those of the reference qRT-PCR assay, the index PCR assay on the field-deployable system can serve as a highly sensitive and specific on-site tool for DENV detection.


Subject(s)
Dengue Virus/isolation & purification , Dengue/diagnosis , Molecular Diagnostic Techniques/methods , Point-of-Care Systems , RNA, Viral/blood , Reverse Transcriptase Polymerase Chain Reaction , Dengue/blood , Dengue Virus/genetics , Humans , Molecular Diagnostic Techniques/standards , RNA, Viral/genetics , Reagent Kits, Diagnostic , Reproducibility of Results , Sensitivity and Specificity , Serogroup
5.
J Feline Med Surg ; 20(4): 362-369, 2018 04.
Article in English | MEDLINE | ID: mdl-28589743

ABSTRACT

Objectives Feline leukaemia virus (FeLV), a gamma retrovirus, causes diseases of the feline haematopoietic system that are invariably fatal. Rapid and accurate testing at the point-of-need (PON) supports prevention of virus spread and management of clinical disease. This study evaluated the performance of an insulated isothermal PCR (iiPCR) that detects proviral DNA, and a reverse transcription (RT)-iiPCR that detects both viral RNA and proviral DNA, for FeLV detection at the PON. Methods Mycoplasma haemofelis, feline coronavirus, feline herpesvirus, feline calicivirus and feline immunodeficiency virus were used to test analytical specificity. In vitro transcribed RNA, artificial plasmid, FeLV strain American Type Culture Collection VR-719 and a clinical FeLV isolate were used in the analytical sensitivity assays. A retrospective study including 116 clinical plasma and serum samples that had been tested with virus isolation, real-time PCR and ELISA, and a prospective study including 150 clinical plasma and serum samples were implemented to evaluate the clinical performances of the iiPCR-based methods for FeLV detection. Results Ninety-five percent assay limit of detection was calculated to be 16 RNA and five DNA copies for the RT-iiPCR, and six DNA copies for the iiPCR. Both reactions had analytical sensitivity comparable to a reference real-time PCR (qPCR) and did not detect five non-target feline pathogens. The clinical performance of the RT-iiPCR and iiPCR had 98.82% agreement (kappa[κ] = 0.97) and 100% agreement (κ = 1.0), respectively, with the qPCR (n = 85). The agreement between an automatic nucleic extraction/RT-iiPCR system and virus isolation to detect FeLV in plasma or serum was 95.69% (κ = 0.95) and 98.67% (κ = 0.85) in a retrospective (n = 116) and a prospective (n = 150) study, respectively. Conclusions and relevance These results suggested that both RT-iiPCR and iiPCR assays can serve as reliable tools for PON FeLV detection.


Subject(s)
Feline Acquired Immunodeficiency Syndrome/diagnosis , Immunodeficiency Virus, Feline/isolation & purification , Real-Time Polymerase Chain Reaction/veterinary , Animals , Cats , Feline Acquired Immunodeficiency Syndrome/virology , Polymerase Chain Reaction/veterinary , Prospective Studies , RNA, Viral/analysis , Retrospective Studies , Sensitivity and Specificity
6.
BMC Infect Dis ; 17(1): 778, 2017 12 19.
Article in English | MEDLINE | ID: mdl-29258444

ABSTRACT

BACKGROUND: The recent emergence of Zika virus (ZIKV) in Brazil and its precipitous expansion throughout the Americas has highlighted the urgent need for a rapid and reliable on-site diagnostic assay suitable for viral detection. Such point-of-need (PON), low-cost diagnostics are essential for ZIKV control in vulnerable areas with limited resources. METHODS: We developed and evaluated a ZIKV-specific field-deployable RT-iiPCR reagent set targeting the E gene for rapid detection of ZIKV in ZIKV-spiked human and mosquito specimens, and compared its performance to the Center for Disease Control and Prevention (CDC) and Pan American Health Organization (PAHO) RT-qPCR assays targeting the E and NS2B genes, respectively. RESULTS: These assays demonstrated exclusive specificity for ZIKV (African and Asian lineages), had limits of detection ranging from 10 to 100 in vitro transcribed RNA copies/µl and detection endpoints at 10 plaque forming units/ml of infectious tissue culture fluid. Analysis of human whole blood, plasma, serum, semen, urine, and mosquito pool samples spiked with ZIKV showed an agreement of 90% (k = 0.80), 92% (k = 0.82), 95% (k = 0.86), 92% (k = 0.81), 90% (k = 0.79), and 100% (k = 1), respectively, between the RT-iiPCR assay and composite results from the reference RT-qPCR assays. Overall, the concurrence between the ZIKV RT-iiPCR and the reference RT-qPCR assays was 92% (k = 0.83). CONCLUSIONS: The ZIKV RT-iiPCR has a performance comparable to the reference CDC and PAHO RT-qPCR assays but provides much faster results (~1.5 h) with a field-deployable system that can be utilized as a PON diagnostic with the potential to significantly improve the quality of the health care system in vulnerable areas.


Subject(s)
RNA, Viral/analysis , Zika Virus Infection/diagnosis , Zika Virus/genetics , Animals , Culicidae/virology , Humans , Point-of-Care Systems , RNA, Viral/blood , RNA, Viral/urine , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Zika Virus/isolation & purification , Zika Virus Infection/virology
7.
Poult Sci ; 96(1): 35-41, 2017 Jan 01.
Article in English | MEDLINE | ID: mdl-27389062

ABSTRACT

Mycoplasma synoviae (MS), causing respiratory diseases, arthritis, and eggshell apex abnormalities in avian species, is an important pathogen in the poultry industry. Implementation of a biosecurity plan is important in MS infection management. Working on a field-deployable POCKIT™ device, an insulated isothermal polymerase chain reaction (iiPCR) assay has a potential for timely MS detection on the farm. The MS iiPCR assay had limit of detection 95% of about 9 genome equivalents by testing serial dilutions of a standard DNA. The detection endpoint of the assay for detection of MS genomic DNA was comparable to a reference real-time PCR. The assay did not crossreact with other important avian pathogens, including avian reovirus, Mycoplasma gallisepticum, Staphylococcus aureus, Escherichia coli, Pasteurella multocida, and Salmonella Pullorum. When 92 synovial fluid and respiratory tract swab samples collected from chickens, turkeys, and geese suspected of MS infection were tested, the clinical performance of the MS iiPCR had 97.8% agreement (Cohen's kappa value, 0.95) with that of the reference real-time PCR. In conclusion, the MS iiPCR/POCKIT™ system, working with field-deployable manual or automatic nucleic acid extraction methods, has potential to serve as a rapid and sensitive on-site tool to facilitate timely detection of MS.


Subject(s)
Bacterial Proteins/isolation & purification , Chickens , Lectins/isolation & purification , Mycoplasma Infections/veterinary , Mycoplasma synoviae/isolation & purification , Poultry Diseases/diagnosis , Real-Time Polymerase Chain Reaction/veterinary , Animals , Mycoplasma Infections/diagnosis , Mycoplasma Infections/microbiology , Poultry Diseases/microbiology , Real-Time Polymerase Chain Reaction/methods , Respiratory System/microbiology , Sensitivity and Specificity , Synovial Fluid/microbiology
8.
J Virol Methods ; 241: 58-63, 2017 03.
Article in English | MEDLINE | ID: mdl-27993615

ABSTRACT

Equine herpesvirus myeloencephalopathy (EHM), a major problem for the equine industry in the United States, is caused by equine herpesvirus-1 (EHV-1). In addition, EHV-1 is associated with upper respiratory disease, abortion, and chorioretinal lesions in horses. Here we describe the development and evaluation of an inexpensive, user-friendly insulated isothermal PCR (iiPCR) method targeting open reading 30 (ORF30) to detect both neuropathogenic and non-neuropathogenic strains on the field-deployable POCKIT™ device for point-of-need detection of EHV-1. The analytical sensitivity of the EHV-1 iiPCR assay was 13 genome equivalents per reaction. The assay did not cross react with ten non-target equine viral pathogens. Performance of the EHV-1 iiPCR assay was compared to two previously described real-time PCR (qPCR) assays in two laboratories by using 104 archived clinical samples. All 53 qPCR-positive and 46 of the 51 qPCR-negative samples tested positive and negative, respectively, by the iiPCR. The agreement between the two assays was 95.19% (confidence interval 90.48-99.90%) with a kappa value of 0.90. In conclusion, the newly developed EHV-1 iiPCR assay is robust to provide specificity and sensitivity comparable to qPCR assays for the detection of EHV-1 nucleic acid in clinical specimens.


Subject(s)
Herpesviridae Infections/veterinary , Herpesvirus 1, Equid/isolation & purification , Horse Diseases/diagnosis , Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction/methods , Animals , DNA, Viral/genetics , DNA, Viral/isolation & purification , Encephalomyelitis/diagnosis , Encephalomyelitis/veterinary , Encephalomyelitis/virology , Herpesviridae Infections/diagnosis , Herpesviridae Infections/virology , Herpesvirus 1, Equid/genetics , Horse Diseases/virology , Horses , Open Reading Frames/genetics , Polymerase Chain Reaction/economics , Sensitivity and Specificity , Temperature
9.
J Virol Methods ; 235: 99-104, 2016 09.
Article in English | MEDLINE | ID: mdl-27180038

ABSTRACT

There is no gold standard for detection of Rotavirus Group A (RVA), one of the main causes of diarrhea in neonatal animals. Sensitive and specific real-time RT-PCR (rtRT-PCR) assays are available for RVA but require submission of the clinical samples to diagnostic laboratories. Patient-side immunoassays for RVA protein detection have shown variable results, particularly with samples from unintended species. A sensitive and specific test for detection of RVA on the farm would facilitate rapid management decisions. The insulated isothermal RT-PCR (RT-iiPCR) assay works in a portable machine to allow sensitive and specific on-site testing. The aim of this investigation was to evaluate a commercially available RT-iiPCR assay for RVA detection in feces from different animal species. This assay was compared to an in-house rtRT-PCR assay and a commercially available rtRT-PCR kit, as well as an ELISA and EM for RVA detection. All three PCR assays targeted the well-conserved NSP5 gene. Clinical fecal samples from 108 diarrheic animals (mainly cattle and horses) were tested. The percentage of positive samples by ELISA, EM, in-house rtRT-PCR, commercial rtRT-PCR, and RT-iiPCR was 29.4%, 31%, 36.7%, 51.4%, 56.9%, respectively. The agreement between different assays was high (81.3-100%) in samples containing high viral loads. The sensitivity of the RT-iiPCR assay appeared to be higher than the commercially available rtRT-PCR assay, with a limit of detection (95% confidence index) of 3-4 copies of in vitro transcribed dsRNA. In conclusion, the user-friendly, field-deployable RT-iiPCR system holds substantial promise for on-site detection of RVA.


Subject(s)
Enzyme-Linked Immunosorbent Assay , Feces/virology , Microscopy, Electron , Reverse Transcriptase Polymerase Chain Reaction , Rotavirus Infections/veterinary , Rotavirus/isolation & purification , Animals , Cattle , Cattle Diseases/diagnosis , Cattle Diseases/virology , Diarrhea/virology , Horse Diseases/diagnosis , Horse Diseases/virology , Horses , Point-of-Care Systems , RNA, Double-Stranded , RNA, Viral/genetics , RNA, Viral/isolation & purification , Reagent Kits, Diagnostic , Real-Time Polymerase Chain Reaction , Rotavirus/genetics , Rotavirus Infections/diagnosis , Rotavirus Infections/virology , Sensitivity and Specificity , Temperature , Viral Load , Viral Nonstructural Proteins/genetics
10.
J Virol Methods ; 234: 34-42, 2016 08.
Article in English | MEDLINE | ID: mdl-27060624

ABSTRACT

Recent outbreaks of porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) in multiple countries have caused significant economic losses and remain a serious challenge to the swine industry. Rapid diagnosis is critical for the implementation of efficient control strategies before and during PEDV and PDCoV outbreaks. Insulated isothermal PCR (iiPCR) on the portable POCKIT™ device is user friendly for on-site pathogen detection. In the present study, a singleplex PEDV RT-iiPCR, a singleplex PDCoV RT-iiPCR, and a duplex PEDV/PDCoV real-time RT-PCR (rRT-PCR) commercial reagents targeting the M gene were compared to an N gene-based PEDV rRT-PCR and an M gene-based PDCoV rRT-PCR that were previously published and used as reference PCRs. All PCR assays were highly specific and did not cross react with other porcine enteric pathogens. Analytical sensitivities of the PEDV RT-iiPCR, PDCoV RT-iiPCR and duplex PEDV/PDCoV rRT-PCR were determined using in vitro transcribed RNA as well as viral RNA extracted from ten-fold serial dilutions of PEDV and PDCoV cell culture isolates. Performance of each PCR assay was further evaluated using 170 clinical samples (86 fecal swabs, 24 feces, 19 intestines, and 41 oral fluids). Compared to the reference PEDV rRT-PCR, the sensitivity, specificity and accuracy of the PEDV RT-iiPCR were 97.73%, 98.78%, and 98.24%, respectively, and those of the duplex PEDV/PDCoV rRT-PCR were 98.86%, 96.34%, and 97.65%, respectively. Compared to the reference PDCoV rRT-PCR, the sensitivity, specificity and accuracy of the PDCoV RT-iiPCR were 100%, 100%, and 100%, respectively, and those of the PEDV/PDCoV duplex rRT-PCR were 96.34%, 100%, and 98.24%, respectively. Overall, all three new PCR assays were comparable to the reference rRT-PCRs for detection of PEDV and/or PDCoV. The PEDV and PDCoV RT-iiPCRs are potentially useful tools for on-site detection and the duplex PEDV/PDCoV rRT-PCR provides a convenient method to simultaneously detect the two viruses and differentiate PEDV from PDCoV.


Subject(s)
Coronaviridae/isolation & purification , Coronavirus Infections/diagnosis , Coronavirus Infections/veterinary , Polymerase Chain Reaction/methods , Porcine epidemic diarrhea virus/isolation & purification , Swine Diseases/diagnosis , Animals , Coronaviridae/genetics , Coronavirus Infections/virology , Feces/virology , Porcine epidemic diarrhea virus/genetics , Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Sensitivity and Specificity , Swine , Swine Diseases/virology , Temperature
11.
J Virol Methods ; 234: 7-15, 2016 08.
Article in English | MEDLINE | ID: mdl-27036504

ABSTRACT

Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory and reproductive disease of horses. Most importantly, EAV induces abortion in pregnant mares and can establish persistent infection in up to 10-70% of the infected stallions, which will continue to shed the virus in their semen. The objective of this study was to develop and evaluate a reverse transcription insulated isothermal polymerase chain reaction (RT-iiPCR) for the detection of EAV in semen and tissue samples. The newly developed assay had a limit of detection of 10 RNA copies and a 10-fold higher sensitivity than a previously described real-time RT-PCR (RT-qPCR). Evaluation of 125 semen samples revealed a sensitivity and specificity of 98.46% and 100.00%, respectively for the RT-qPCR assay, and 100.00% and 98.33%, respectively for the RT-iiPCR assay. Both assays had the same accuracy (99.2%, k=0.98) compared to virus isolation. Corresponding values derived from testing various tissue samples (n=122) collected from aborted fetuses, foals, and EAV carrier stallions are as follows: relative sensitivity, specificity, and accuracy of 88.14%, 96.83%, and 92.62% (k=0.85), respectively for the RT-qPCR assay, and 98.31%, 92.06%, and 95.08% (k=0.90), respectively for the RT-iiPCR assay. These results indicate that RT-iiPCR is a sensitive, specific, and a robust test enabling detection of EAV in semen and tissue samples with very considerable accuracy. Even though the RT-qPCR assay showed a sensitivity and specificity equal to virus isolation for semen samples, its diagnostic performance was somewhat limited for tissue samples. Thus, this new RT-iiPCR could be considered as an alternative tool in the implementation of EAV control and prevention strategies.


Subject(s)
Arterivirus Infections/veterinary , Equartevirus/isolation & purification , Horse Diseases/diagnosis , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Semen/virology , Animals , Arterivirus Infections/diagnosis , Arterivirus Infections/prevention & control , Arterivirus Infections/virology , Female , Horse Diseases/virology , Horses , Male , Open Reading Frames , Pregnancy , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , Sensitivity and Specificity , Temperature
12.
J Clin Microbiol ; 54(6): 1528-1535, 2016 06.
Article in English | MEDLINE | ID: mdl-27030492

ABSTRACT

Dengue virus (DENV) infection is considered a major public health problem in developing tropical countries where the virus is endemic and continues to cause major disease outbreaks every year. Here, we describe the development of a novel, inexpensive, and user-friendly diagnostic assay based on a reverse transcription-insulated isothermal PCR (RT-iiPCR) method for the detection of all four serotypes of DENV in clinical samples. The diagnostic performance of the newly established pan-DENV RT-iiPCR assay targeting a conserved 3' untranslated region of the viral genome was evaluated. The limit of detection with a 95% confidence was estimated to be 10 copies of in vitro-transcribed (IVT) RNA. Sensitivity analysis using RNA prepared from 10-fold serial dilutions of tissue culture fluid containing DENVs suggested that the RT-iiPCR assay was comparable to the multiplex real-time quantitative RT-PCR (qRT-PCR) assay for DENV-1, -3, and -4 detection but 10-fold less sensitive for DENV-2 detection. Subsequently, plasma collected from patients suspected of dengue virus infection (n = 220) and individuals not suspected of dengue virus infection (n = 45) were tested by the RT-iiPCR and compared to original test results using a DENV NS1 antigen rapid test and the qRT-PCR. The diagnostic agreement of the pan-DENV RT-iiPCR, NS1 antigen rapid test, and qRT-PCR tests was 93.9%, 84.5%, and 97.4%, respectively, compared to the composite reference results. This new RT-iiPCR assay along with the portable POCKIT nucleic acid analyzer could provide a highly reliable, sensitive, and specific point-of-need diagnostic assay for the diagnosis of DENV in clinics and hospitals in developing countries.


Subject(s)
Dengue Virus/isolation & purification , Dengue/diagnosis , Molecular Diagnostic Techniques/methods , Point-of-Care Systems , Reverse Transcriptase Polymerase Chain Reaction/methods , Dengue Virus/genetics , Humans , Sensitivity and Specificity
13.
J Vet Diagn Invest ; 27(4): 510-5, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26185125

ABSTRACT

Feline immunodeficiency virus (FIV) is an important infectious agent of cats. Clinical syndromes resulting from FIV infection include immunodeficiency, opportunistic infections, and neoplasia. In our study, a 5' long terminal repeat/gag region-based reverse transcription insulated isothermal polymerase chain reaction (RT-iiPCR) was developed to amplify all known FIV strains to facilitate point-of-need FIV diagnosis. The RT-iiPCR method was applied in a point-of-need PCR detection platform--a field-deployable device capable of generating automatically interpreted RT-iiPCR results from nucleic acids within 1 hr. Limit of detection 95% of FIV RT-iiPCR was calculated to be 95 copies standard in vitro transcription RNA per reaction. Endpoint dilution studies with serial dilutions of an ATCC FIV type strain showed that the sensitivity of lyophilized FIV RT-iiPCR reagent was comparable to that of a reference nested PCR. The established reaction did not amplify any nontargeted feline pathogens, including Felid herpesvirus 1, feline coronavirus, Feline calicivirus, Feline leukemia virus, Mycoplasma haemofelis, and Chlamydophila felis. Based on analysis of 76 clinical samples (including blood and bone marrow) with the FIV RT-iiPCR, test sensitivity was 97.78% (44/45), specificity was 100.00% (31/31), and agreement was 98.65% (75/76), determined against a reference nested-PCR assay. A kappa value of 0.97 indicated excellent correlation between these 2 methods. The lyophilized FIV RT-iiPCR reagent, deployed on a user-friendly portable device, has potential utility for rapid and easy point-of-need detection of FIV in cats.


Subject(s)
Feline Acquired Immunodeficiency Syndrome/diagnosis , Immunodeficiency Virus, Feline/isolation & purification , Animals , Cats , Feline Acquired Immunodeficiency Syndrome/virology , Immunodeficiency Virus, Feline/genetics , Point-of-Care Systems , Polymerase Chain Reaction/veterinary , RNA, Viral/analysis , Reproducibility of Results , Sensitivity and Specificity
14.
J Virol Methods ; 220: 35-8, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25889355

ABSTRACT

Canine parvovirus type 2 (CPV-2), including subtypes 2a, 2b and 2c, causes an acute enteric disease in both domestic and wild animals. Rapid and sensitive diagnosis aids effective disease management at points of need (PON). A commercially available, field-deployable and user-friendly system, designed with insulated isothermal PCR (iiPCR) technology, displays excellent sensitivity and specificity for nucleic acid detection. An iiPCR method was developed for on-site detection of all circulating CPV-2 strains. Limit of detection was determined using plasmid DNA. CPV-2a, 2b and 2c strains, a feline panleukopenia virus (FPV) strain, and nine canine pathogens were tested to evaluate assay specificity. Reaction sensitivity and performance were compared with an in-house real-time PCR using serial dilutions of a CPV-2b strain and 100 canine fecal clinical samples collected from 2010 to 2014, respectively. The 95% limit of detection of the iiPCR method was 13 copies of standard DNA and detection limits for CPV-2b DNA were equivalent for iiPCR and real-time PCR. The iiPCR reaction detected CPV-2a, 2b and 2c and FPV. Non-targeted pathogens were not detected. Test results of real-time PCR and iiPCR from 99 fecal samples agreed with each other, while one real-time PCR-positive sample tested negative by iiPCR. Therefore, excellent agreement (k = 0.98) with sensitivity of 98.41% and specificity of 100% in detecting CPV-2 in feces was found between the two methods. In conclusion, the iiPCR system has potential to serve as a useful tool for rapid and accurate PON, molecular detection of CPV-2.


Subject(s)
Dog Diseases/diagnosis , Dog Diseases/virology , Parvoviridae Infections/veterinary , Parvovirus, Canine/isolation & purification , Point-of-Care Systems , Polymerase Chain Reaction/instrumentation , Polymerase Chain Reaction/methods , Animals , Dogs , Feces/virology , Parvoviridae Infections/diagnosis , Parvoviridae Infections/virology , Sensitivity and Specificity , Time Factors
15.
BMC Vet Res ; 10: 213, 2014 Sep 09.
Article in English | MEDLINE | ID: mdl-25200113

ABSTRACT

BACKGROUND: Canine distemper virus (CDV) has been associated with outbreaks of canine infectious respiratory disease in shelters and boarding kennel environments. POCKITTM Nucleic Acid Analyzer is a field-deployable device capable of generating automatically interpreted insulated isothermal polymerase chain reaction (iiPCR) results from extracted nucleic acid within one hour. In this study, reverse transcription iiPCR (RT-iiPCR) was developed to facilitate point-of-need diagnosis of CDV infection. RESULTS: Analytical sensitivity (limit of detection 95%) of the established CDV RT-iiPCR was about 11 copies of in vitro transcribed RNA per reaction. CDV RT-iiPCR generated positive signals from CDV, but not Bordetella bronchiseptica, canine parvovirus, canine herpesvirus, canine adenovirus 2, canine influenza virus (subtype H3N8), canine parainfluenza virus, and canine respiratory coronavirus. To evaluate accuracy of the established reaction in canine distemper clinical diagnosis, 110 specimens from dogs, raccoons, and foxes suspected with CDV infection were tested simultaneously by CDV RT-iiPCR and real-time RT-PCR. CDV RT-iiPCR demonstrated excellent sensitivity (100%) and specificity (100%), compared to real-time RT-PCR. CONCLUSIONS: The results indicated an excellent correlation between RT-iiPCR and a reference real time RT-PCR method. Working in a lyophilized format, the established method has great potential to be used for point-of-care diagnosis of canine distemper in animals, especially in resource-limited facilities.


Subject(s)
Distemper Virus, Canine/isolation & purification , Distemper/virology , Polymerase Chain Reaction/veterinary , Animals , Distemper/diagnosis , Dogs , Polymerase Chain Reaction/methods , RNA, Viral/isolation & purification , Reproducibility of Results , Sensitivity and Specificity , Time Factors
16.
J Virol Methods ; 207: 66-72, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24992669

ABSTRACT

Equine influenza (EI) is an acute, highly contagious viral respiratory disease of equids. Currently, equine influenza virus (EIV) subtype H3N8 continues to be the most important respiratory pathogen of horses in many countries around the world. The need to achieve a rapid diagnosis and to implement effective quarantine and movement restrictions is critical in controlling the spread of EIV. In this study, a novel, inexpensive and user-friendly assay based on an insulated isothermal RT-PCR (iiRT-PCR) method on the POCKIT™, a field-deployable device, was described and validated for point-of-need detection of EIV-H3N8 in clinical samples. The newly established iiRT-PCR assay targeting the EIV HA3 gene was evaluated for its sensitivity using in vitro transcribed (IVT) RNA, as well as ten-fold serial dilutions of RNA extracted from the prototype H3N8 strain A/equine/Miami/1/63. Inclusivity and exclusivity panels were tested for specificity evaluation. Published real-time RT-PCR (rRT-PCR) assays targeting the NP and HA3 genes were used as the reference standards for comparison of RNA extracted from field strains and from nasal swab samples collected from experimentally infected horses, respectively. Limit of detection with a 95% probability (LoD95%) was estimated to be 11copies of IVT RNA. Clinical sensitivity analysis using RNA prepared from serial dilutions of a prototype EIV (Miami 1/63/H3N8) showed that the iiRT-PCR assay was about 100-fold more sensitive than the rRT-PCR assay targeting the NP gene of EIV subtype H3N8. The iiRT-PCR assay identified accurately fifteen EIV H3N8 strains and two canine influenza virus (CIV) H3N8 strains, and did not cross-react with H6N2, H7N7, H1N1 subtypes or any other equine respiratory viral pathogens. Finally, 100% agreement was found between the iiRT-PCR assay and the universal influenza virus type A rRT-PCR assay in detecting the EIV A/equine/Kentucky/7/07 strain in 56 nasal swab samples collected from experimentally inoculated horses. Therefore, the EIV H3N8 subtype specific iiRT-PCR assay along with the portable POCKIT™ Nucleic Acid Analyzer provides a highly reliable, sensitive and specific on-site detection system of both equine and canine influenza viruses.


Subject(s)
Influenza A Virus, H3N8 Subtype/isolation & purification , Molecular Diagnostic Techniques/instrumentation , Molecular Diagnostic Techniques/methods , Reverse Transcriptase Polymerase Chain Reaction/instrumentation , Reverse Transcriptase Polymerase Chain Reaction/methods , Veterinary Medicine/instrumentation , Veterinary Medicine/methods , Animals , Horses , Influenza A Virus, H3N8 Subtype/genetics , Orthomyxoviridae Infections/diagnosis , Orthomyxoviridae Infections/veterinary , Orthomyxoviridae Infections/virology , Point-of-Care Systems , Sensitivity and Specificity
17.
PLoS One ; 9(3): e90545, 2014.
Article in English | MEDLINE | ID: mdl-24625894

ABSTRACT

Timely pond-side detection of white spot syndrome virus (WSSV) plays a critical role in the implementation of bio-security measures to help minimize economic losses caused by white spot syndrome disease, an important threat to shrimp aquaculture industry worldwide. A portable device, namely POCKIT™, became available recently to complete fluorescent probe-based insulated isothermal PCR (iiPCR), and automatic data detection and interpretation within one hour. Taking advantage of this platform, the IQ Plus™ WSSV Kit with POCKIT system was established to allow simple and easy WSSV detection for on-site users. The assay was first evaluated for its analytical sensitivity and specificity performance. The 95% limit of detection (LOD) of the assay was 17 copies of WSSV genomic DNA per reaction (95% confidence interval [CI], 13 to 24 copies per reaction). The established assay has detection sensitivity similar to that of OIE-registered IQ2000™ WSSV Detection and Protection System with serial dilutions of WSSV-positive Litopenaeus vannamei DNA. No cross-reaction signals were generated from infectious hypodermal and haematopoietic necrosis virus (IHHNV), monodon baculovirus (MBV), and hepatopancreatic parvovirus (HPV) positive samples. Accuracy analysis using 700 L. vannamei of known WSSV infection status shows that the established assayhassensitivity93.5% (95% CI: 90.61-95.56%) and specificity 97% (95% CI: 94.31-98.50%). Furthermore, no discrepancy was found between the two assays when 100 random L. vannamei samples were tested in parallel. Finally, excellent correlation was observed among test results of three batches of reagents with 64 samples analyzed in three different laboratories. Working in a portable device, IQ Plus™ WSSV Kit with POCKIT system allows reliable, sensitive and specific on-site detection of WSSV in L. vannamei.


Subject(s)
Penaeidae/virology , Polymerase Chain Reaction/instrumentation , Virus Diseases/diagnosis , Virus Diseases/veterinary , Animals , Aquaculture , DNA, Viral/isolation & purification , Electronic Data Processing , Limit of Detection , Reproducibility of Results , Sensitivity and Specificity , White spot syndrome virus 1/genetics
18.
J Food Prot ; 76(8): 1322-9, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23905786

ABSTRACT

Consumption of Salmonella-contaminated foods, such as poultry and fresh eggs, is known to be one of the main causes of salmonellosis. Conventional PCR methods, including real-time PCR for rapid detection of Salmonella, in general require skilled technicians and costly instruments. A recently developed novel convective PCR, insulated isothermal PCR (iiPCR), is carried out in polycarbonate capillary tubes. In this study, we designed TaqMan probes and PCR primers based on the yrfH gene encoding a heat shock protein for the iiPCR detection of Salmonella in chicken meat samples. The TaqMan probe was labeled with 6-carboxyfluorescein and 6-carboxytetramethylrhodamine at the 5' and 3' ends, respectively. The PCR amplicon was 133 bp. A typical run of this iiPCR assay was completed within 1 h. Specific PCR products were obtained for 148 strains representing 49 serotypes of Salmonella tested. Under the same conditions, false-positive results were not obtained for 98 non-Salmonella strains tested, including strains of Enterobacteriaceae closely related to Salmonella. For chicken meat samples, with a 5-h enrichment step Salmonella at as low as 10° CFU/g of poultry meat could be detected. Because the amplification signals from the probes are detectable at 520 nm, identification of the PCR products by gel electrophoresis is not required. Compared with conventional PCR, the iiPCR system requires less expertise and provides an economical, reliable, and rapid tool for result interpretation. Detection results can be obtained within 8 h, including the enrichment and DNA extraction steps.


Subject(s)
Chickens/microbiology , DNA, Bacterial/analysis , Food Contamination/analysis , Meat/microbiology , Polymerase Chain Reaction/methods , Salmonella/isolation & purification , Animals , DNA Primers , DNA, Bacterial/genetics , DNA, Bacterial/metabolism , Fluoresceins , Polymerase Chain Reaction/standards , Reproducibility of Results , Rhodamines , Salmonella/genetics , Salmonella/metabolism , Salmonella Food Poisoning/prevention & control , Sensitivity and Specificity , Time Factors
19.
PLoS One ; 7(9): e45278, 2012.
Article in English | MEDLINE | ID: mdl-23049781

ABSTRACT

Insulated isothermal PCR (iiPCR), established on the basis of Ralyeigh-Bénard convection, is a rapid and low-cost platform for nucleic acid amplification. However, the method used for signal detection, namely gel electrophoresis, has limited the application of iiPCR. In this study, TaqMan probe-based iiPCR system was developed to obviate the need of post-amplification processing. This system includes an optical detection module, which was designed and integrated into the iiPCR device to detect fluorescent signals generated by the probe. TaqMan probe-iiPCR assays targeting white spot syndrome virus (WSSV) and infectious myonecrosis virus were developed for preliminary evaluation of this system. Significant elevation of fluorescent signals was detected consistently among positive iiPCR reactions in both assays, correlating with amplicon detection by gel electrophoresis analysis. After condition optimization, a threshold value of S/N (fluorescent intensity(after)/fluorescent intensity(before)) for positive reactions was defined for WSSV TaqMan probe-iiPCR on the basis of 20 blank reactions. WSSV TaqMan probe-iiPCR generated positive S/Ns from as low as 10(1) copies of standard DNA and lightly infected Litopenaeus vannamei. Compared with an OIE-certified nested PCR, WSSV TaqMan probe-iiPCR showed a sensitivity of 100% and a specificity of 96.67% in 120 WSSV-free or lightly infected shrimp samples. Generating positive signals specifically and sensitively, TaqMan probe-iiPCR system has a potential as a low-cost and rapid on-site diagnostics method.


Subject(s)
Penaeidae/virology , Polymerase Chain Reaction/methods , Totiviridae/genetics , Totiviridae/isolation & purification , White spot syndrome virus 1/genetics , White spot syndrome virus 1/isolation & purification , Animals , DNA Primers/genetics , Nucleic Acid Denaturation , Polymerase Chain Reaction/instrumentation , Sensitivity and Specificity , Temperature
20.
Biotechnol J ; 7(5): 662-6, 2012 May.
Article in English | MEDLINE | ID: mdl-22241586

ABSTRACT

Rayleigh-Bénard convective PCR is a simple and effective design for amplification of DNA. Convective PCR is, however, extremely sensitive to environmental temperature fluctuations, especially when using small- diameter test tubes. Therefore, this method is inherently unstable with limited applications. Here, we present a convective PCR device that has been modified by adding thermal baffles. With this thermally baffled device the influence from fluctuations in environmental temperature were significantly reduced, even in a wind tunnel (1 m/s). The thermally baffled PCR instrument described here has the potential to be used as a low-cost, point-of-care device for PCR-based molecular diagnostics in the field.


Subject(s)
Polymerase Chain Reaction/instrumentation , Polymerase Chain Reaction/methods , Convection , DNA, Complementary/genetics , Electrophoresis, Agar Gel , Equipment Design , Plasmids/genetics , Roniviridae/genetics , Temperature , Time Factors
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