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ABSTRACT Introduction: In Brazil, the blood donor screening for hepatitis B virus (HBV) includes laboratory testing for serological (HBsAg and Anti-HBc) and molecular (HBV DNA) markers. This study aims to correlate serology reactive results with HBV DNA detection among blood donors with at least one HBV infection marker detected in a blood bank in northern Brazil. Method: A retrospective search for HBV reactive blood donor data from January 2017 to December 2019 was performed. Serological screening was performed by chemiluminescent microparticle immunoassays Architect HBsAg and Architect Anti-HBc, whereas molecular screening was performed by the HBV nucleic acid test (HBV NAT). Main results: A total of 556 HBsAg reactive results were detected, between positive (47.66%) and inconclusive (52.34%). A total of 3,658 Anti-HBc reactive results were detected, between positive (83.71%) and inconclusive (16.29%). None of the inconclusive results were associated with HBV DNA detection. The HBV DNA detection rates were 47.55% among HBsAg positive samples and 4.08% among Anti-HBc positive samples. The signal-to-cutoff (S/CO) ratio median of HBV NAT positive samples was superior in comparison to HBV NAT negative samples (p < 0.0001). The thresholds found to optimize sensitivity and specificity were 404.15 for Architect HBsAg and 7.77 for Architect Anti-HBc. Three blood donors were in the window period and 1 occult HBV infection case was detected. Conclusion: High S/CO ratios were more predictive of HBV DNA detection. However, a number of HBV NAT positive samples gave low values, while some HBV NAT negative samples showed high values, reaffirming the significance of molecular testing to enhance transfusion safety.
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@#Abstract: Objective To compare the diagnostic efficacy of the upgraded version of the GeneXpert automated fluorescent quantitative PCR system (GeneXpert MTB/RIF Ultra, GeneXpert Ultra) and the original version of the GeneXpert system (GeneXpert MTB/RIF, Xpert), real-time fluorescent quantitative nucleic acid detection (FQ-PCR), real-time fluorescent thermostatic amplification of Mycobacterium tuberculosis RNA (SAT-RNA), real-time fluorescent thermostatic amplification detection of DNA (thermostatic amplification method) and traditional BACTEC MGIT 960 liquid culture (culture method) for special specimens of tuberculosis, in order to analyze its application value in clinical detection. Methods Using prospective research methods, a total of 170 special specimens (including 47 pleural and ascites effusion samples, and 34 24-hour urinary sediment specimens, 49 tissue specimens and 40 fester specimens) were collected i'an Chest Hospital from January to September 2021. GeneXpert Ultra, Xpert, FQ-PCR, SAT-RNA, isothermal amplification, and traditional culture were used for detection. Clinical diagnosis was used as the standard, and sensitivity, specificity, positive predictive value, negative predictive value, coincidence rate, and Kappa value were compared among the methods. Results The sensitivities of GeneXpert Ultra, Xpert, FQ-PCR, SAT-RNA, isothermal amplification, and traditional culture were 65.18% (73/112), 49.11% (55/112), 37.50% (42/112), 19.64% (22/112), 8.04% (9/112), and 22.32% (25/112), respectively. The sensitivity of GeneXpert Ultra was higher than that of the other five methods, and the differences were statistically significant (χ2=66.25, 42.10, 28.89, 13.09, 4.92, 15.18, all P<0.05). GeneXpert Ultra result analysis showed that: 5.48%(4/73) cases had trace, that is, trace Mycobacterium tuberculosis load, 79.45% (58/73) cases were extremely low, 10.96% (8/73) cases were low, 2.74% (2/73) were medium, , and 1.36% (1/73) were high load. In 4 trace samples, the Xpert detection was negative for all. Of the 73 GeneXpert Ultra positive reports, 63 were rifampicin-sensitive, 6 were rifampicin-resistant, and 4 were rifampicin-resistant but of unclear resistance. Of the 55 Xpert positive reports, 45 were rifampicin-sensitive, 2 were rifampicin-resistant, and 8 were rifampicinresistant but of unclear resistance.. Conclusions The new generation of GeneXpert MTB/RIF Ultra has high sensitivity, specificity and drug resistance detection rate, and its advantage is even more apparent in the pathogenic diagnosis of special specimens of tuberculosis. It can be used as one of the preferred methods in samples with low bacterial load.
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Objective:To compare the cost-effectiveness of hospitalized Chinese patients undergoing nucleic acid screening strategies for hepatitis B and hepatitis C, immunological screening strategy, and no screening strategy under different willingness to pay (WTP). The results might aid to decision-making for the optimal strategy.Methods:In this study, nucleic acid screening, immunological screening and no screening were used as screening strategies, and China′s GDP in 2021 (80 976 yuan) was used as the threshold of WTP to construct a Markov model. After introducing parameters related to the diagnosis and treatment of hepatitis B and C in inpatients, a cohort population of 100 000 inpatients was simulated by TreeAge Pro 2021 software, the total cost, total health effects, incremental cost-effectiveness ratio and average cost-effectiveness ratio of different screening strategies were calculated, and cost-effectiveness analysis was conducted. Univariate and probabilistic sensitivity analysis were used to assess the impact of parameter uncertainty on the final results.Results:Compared with the non-screening strategy, the incremental total cost of the hepatitis B immunological screening strategy for cohort patients was 11 049 536 yuan, and the incremental cost-effectiveness ratio was 24 762 yuan/quality-adjusted life years (QALY), while the total incremental cost of nucleic acid screening was 19 208 059 yuan, and the incremental cost-effectiveness ratio was 29 873 yuan/QALY; the incremental cost-effectiveness ratio of nucleic acid screening and immunological screening was 45 834 yuan/QALY. Compared with the non-screening strategy, the incremental cost-effectiveness ratio of hepatitis C immunological screening strategy was 5 731 yuan/QALY, the incremental cost-effectiveness ratio of nucleic acid screening strategy was 8 722 yuan/QALY, the incremental cost-effectiveness ratio of nucleic acid screening and immunological screening was 45 591 yuan/QALY. The results of probabilistic sensitivity analysis showed that when the cost of nucleic acid testing exceeded 214.53 yuan, it was not cost-effective to perform hepatitis B nucleic acid screening under the WTP as 1 fold GDP. When the cost of nucleic acid testing exceeded 132.18 yuan, it was not cost-effective to conduct hepatitis C screening under the WTP as 1 fold GDP.Conclusions:Nucleic acid screening strategy can achieve more cost-effectiveness and is worthy of vigorous promotion. Compared with no screening, both the nucleic acid and immunological screening strategies are cost-effective, and hepatitis nucleic acid screening is the optimal strategy for hospitalized patients.
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Objective:This multi-centre study was conducted to assess the efficacy of various preoperative/pre-transfusion screening methods for blood transmitted disease.Methods:From July 2021 to December 2021, plasma samples of patients admitted to 10 hospitals were collected for screening preoperative/pre-transfusion blood transmitted disease. Nucleic acid detection technology was used to detect hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA and human immunodeficiency virus (HIV)(1+2) RNA, and the results were compared with the immuno-serological methods. χ 2 test and Kappa test were used to analyze the efficacy of these two methods. Results:A total of 8 655 valid specimens were collected from 10 hospitals. There was a statistically significant difference in the positive detection rate of HCV between the two methods ( P<0.001). There was no significant difference in the positive detection rate of HBV and HIV assessed by the two methods ( P>0.05), but the number of positive cases detected by HBV DNA and HIV RNA (218 and 4 cases) was significantly higher than the corresponding serological results (216 and 2 cases). At the same time, there were HBV, HCV and HIV immuno-serological omissions by the immuno-serological methods, among which 28 cases were HBsAg negative and HBV DNA positive, 2 cases were HCV antibody negative and HCV RNA positive, and 2 cases were HIV antigen/antibody negative and HIV RNA positive. In addition, in the 66 samples with inconsistent results from the two detection methods, 83.3% (55/66), 68.2% (45/66), 63.6% (42/66) and 62.1% (41/66) of patients aged was>45 years, tumor, surgery and male, respectively. Conclusions:Compared with immuno-serological tests, nucleic acid tests have the advantage in terms of sensitivity on detecting HBV, HCV and HIV infection and could reduce missed detection. The risk of transmission can be reduced by adding HBV, HCV, and HIV nucleic acid tests to preoperative/pre-transfusion immuno-serological tests screening for patients over 45 years of age and tumor patients.
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Objective:To explore clinical value of nucleic acid detection for hepatitis B virus (HBV) screening in hospitalized patients.Methods:This cross-sectional study collected and analyzed plasma samples from patients admitted to 10 domestic medical institutions from July 2021 to December 2021. Serological immunoassay and nucleic acid screening were used to simultaneously detect hepatitis B markers such as hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), hepatitis B e Antigen (HBeAg), hepatitis B e antibody (HBeAb), hepatitis B core antibody (HBcAb),and HBV DNA. Statistical analysis was performed on the serology, nucleic acid test results and clinical information of the patients.Results:Of the 8 655 collected samples, HBsAg was positive in 216 (2.50%) samples,HBV DNA was positive in 238 (2.75%) samples ( P>0.05); 210 (2.43%) samples were positive for both HBsAg and HBV DNA, 28 (0.32%) were HBsAg negative and HBV DNA positive, 6 cases (0.07%) were HBsAg positive and HBV DNA negative. Conclusion:These results indicate that the HBV DNA testing is equally effective as hepatitis B virus serological detection for hepatitis B virus screening in hospitalized patients.
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Objective:To explore the clinical significance of hepatitis B virus (HBV) DNA detection in screening patients with hepatitis B.Methods:Clinical data of 682 331 hepatitis B patients were retrospectively analyzed. The HBV DNA of these patients was detected in the Fifth Medical Center of the PLA General Hospital from January 2017 to December 2021, there were 481 159 males and 201 172 females in this cohort, the average age was (41.34±16.13) years. Patients were divided into HBV DNA positive group (219 879 cases) and HBV DNA negative group (462 452 cases). Clinical characteristics, data of five serologic markers of hepatitis B and hepatitis B surface antigen quantification (HBsAg-QN), liver function, alpha fetoprotein (AFP) and prothrombin time (PT) results were collected and analyzed and compared between the two groups.Results:The positive rate of HBV DNA was 32.22% (219 879/682 331) in this cohort. Among the different age groups, the positive rate of HBV DNA was the highest (40.34%, 128 038/317 380) in young people aged 18-44 years. The proportion of patients was lower among aged <1, 45-59 and ≥60 years patients in HBV DNA positive group than that in HBV DNA negative group, while the proportion of patients was higher among aged 1-17 and 18-44 years patients in HBV DNA positive group than that in HBV DNA negative group (all P<0.001). Among 2 291 <1-year-old infants tested for HBV DNA, 71 infants were HBV DNA positive. The positive rates of HBV DNA from 2017 to 2021 were 4.86% (27/556), 3.68% (14/380), 3.47% (17/490), 1.55% (6/386) and 1.46% (7/479) respectively, showing a downward trend year by year. The positive rate of HBV DNA in acute hepatitis B (AHB) patients was the highest (49.88%, 208/417) among 680 040 patients with hepatitis B. The proportion of AHB patients (0.09%, 208/219 808) and chronic hepatitis B (80.44%, 176 806/219 808) in HBV DNA positive group was higher than that in HBV DNA negative group [0.05% (209/460 232) and 65.45% (301, 216/460 232)], while the proportion of patients with HBV-related liver cirrhosis (11.28%, 24 793/219 808), HBV-related liver cancer (6.72%, 14 775/219 808), liver cancer surgery (1.39%, 3 055/219 808) and liver transplantation (0.08%, 171/219 808) were lower than that in HBV DNA negative group [22.99% (105 813/460 232), 7.25% (33 385/460 232), 3.50% (16 129/460 232) and 0.76% (3 480/460 232)] (all P<0.001). At the same time, positive rate of hepatitis B surface antigen (HbsAg), HBsAg-QN, hepatitis B e antigen (HbeAg), level of total bilirubin, total bilirubin, AFP and PT were higher in HBV DNA positive group than those in HBV DNA negative group, while the age, male ratio and albumin results in HBV DNA positive group were lower than those in HBV DNA negative group (all P<0.01). The HBV DNA loads were higher in HBsAg positive group, hepatitis B surface antibody positive group and HBeAg positive group than those in respective negative groups, while the HBV DNA loads were lower in hepatitis B e antibody positive group and hepatitis B core antibody positive group than those in respective negative groups (all P<0.001). Conclusions:The mother to child transmission rate of<1-year-old infants decreases year by year. HBV DNA is an important factor for the progression of hepatitis B disease. HBV DNA positive hepatitis B patients with higher HBsAg-QN values are more likely to have abnormal serum markers such as liver dysfunction. HBV DNA detection is therefore of clinical importance in screening patients with hepatitis B.
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For patients with chronic hepatitis B, the indications of antiviral treatment are gradually expanding, and the pursuit of various degrees of cure (partial cure, functional cure and complete cure) is consistently improving, which enhances the urgent clinical need for improving the detection sensitivity of hepatitis B virus (HBV) surface antigen and DNA. Based on the availability of commercial highly sensitive hepatitis B surface antigen and HBV DNA detection reagents, we summarized their applications in the diagnosis of HBV infection, their role on guiding selection of antiviral treatment agents and treatment plans, their prediction efficacy and indication for drug withdrawal, their role on monitoring therapy efficacy and the prediction of disease outcomes. Taken together, highly sensitive hepatitis B virus surface antigen and DNA assays and related detection technology play an important role in the whole management process of chronic HBV infection.
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Resumen: Introducción: el inicio temprano de la antibioticoterapia adecuada en infecciones graves se asocia con reducción de la mortalidad. La identificación precoz del microorganismo es fundamental para realizar un tratamiento dirigido y disminuir la terapéutica inicial inapropiada. Objetivo: valorar la utilidad de una técnica de biología molecular por amplificación de ácidos nucleicos mediante reacción en cadena de polimerasa en tiempo real para diagnóstico microbiológico temprano y adecuación de la antibioticoterapia en pacientes con neumonías graves. Metodología: estudio retrospectivo observacional llevado a cabo en la unidad de cuidados intensivos del Hospital Maciel. Se analizaron muestras respiratorias de pacientes con diagnóstico o sospecha de neumonía. Se compararon los resultados microbiológicos obtenidos por técnicas convencionales y por biología molecular multiplex (panel neumonía). Resultados: se incluyeron 53 muestras obtenidas de 51 pacientes. El multiplex detectó al menos un microorganismo en 38 (71,7%) muestras frente a 30 (56.6%) desarrollos en cultivos tradicionales. La mayoría de las muestras se obtuvieron bajo antibioticoterapia previa (86.8%). El panel neumonía mostró un porcentaje de concordancia positiva combinado de 100% y un porcentaje de concordancia negativa del 94% para la identificación bacteriana en comparación con los métodos microbiológicos tradicionales. En 27 (51%) casos el resultado del panel de neumonía determinó un cambio en la conducta terapéutica. Conclusiones: la técnica de PCR permite la identificación temprana de microorganismos causantes de neumonía optimizando la terapéutica empírica inicial y racionalizando el uso de antimicrobianos. Un panel negativo aleja el planteo de infección respiratoria a gérmenes habituales y permite considerar diagnósticos diferenciales en cuanto a foco y/o etiología.
Summary: Introduction: the early initiation of the adequate antibiotic therapy in severe infections is associated to a reduction in mortality. Early identification of the microorganism is essential to define directed therapy and decrease the initial inadequate treatment. Objective: to assess usefulness of a molecular biology technique by nucleic acid amplification through a polymerase chain reaction in real time for an early microbiological diagnosis and correction of the antibiotic therapy in patients with severe pneumonias. Method: retrospective, observational study conducted in the intensive care unit of Maciel Hospital. The respiratory samples of patients with a diagnosis of pneumonia or suspicious to have pneumonia were analyzed. The microbiological results obtained were compared using conventional techniques and multiplex molecular biology (pneumonia panel). Results: 53 samples obtained from 51 patients were included in the study. Multiplex detected at least one microorganism in 38 (71.7%) samples compared to 30 (56.6%) in traditional cultures. Most samples were obtained under the previous antibiotic therapy (86.8%). The pneumonia panel showed a combined positive agreement percentage of 100% and a negative agreement of 94% for the identification of bacteria when compared to the traditional microbiological methods. In 27 cases (51%) the pneumonia panel results determined changing the therapeutic behavior. Conclusions: the PCR technique allows for the early identification of microorganisms causing pneumonia, thus optimizing initial empirical therapy and rationalizing the use of antibiotics. A negative panel reduces the suspicion of a respiratory infection caused by the usual germs and enables considering differential diagnosis in terms of etiology or cause.
Resumo: Introdução: o início precoce da antibioticoterapia adequada em infecções graves está associado à redução da mortalidade. A identificação precoce do microrganismo é essencial para realizar o tratamento dirigido e reduzir o uso inicial inadequado de antimicrobianos. Objetivo: avaliar a utilidade de uma técnica de biologia molecular para amplificação de ácidos nucleicos por reação em cadeia da polimerase em tempo real para diagnóstico microbiológico precoce e adequação da antibioticoterapia em pacientes com pneumonia grave. Metodologia: estudo observacional retrospectivo realizado na unidade de terapia intensiva do Hospital Maciel. Amostras respiratórias de pacientes com diagnóstico ou suspeita de pneumonia foram analisadas. Os resultados microbiológicos obtidos por técnicas convencionais e por biologia molecular multiplex (painel de pneumonia) foram comparados. Resultados: foram incluídas 53 amostras obtidas de 51 pacientes. O multiplex detectou pelo menos um microrganismo em 38 (71,7%) amostras em comparação com 30 (56,6%) usando culturas tradicionais. A maioria das amostras foi obtida com antibioticoterapia prévia (86,8%). O painel de pneumonia mostrou uma concordância percentual positiva combinada de 100% e uma concordância percentual negativa de 94% para identificação bacteriana em comparação com métodos microbiológicos tradicionais. Em 27 (51%) casos, o resultado do painel de pneumonia determinou mudança no comportamento terapêutico. Conclusões: a técnica de PCR permite a identificação precoce de microrganismos causadores de pneumonia, otimizando a terapia empírica inicial e racionalizando o uso de antimicrobianos. Um painel negativo afasta a suspeita de infecção respiratória pelos germes usuais e permite considerar diagnósticos diferenciais em termos de foco e/ou etiologia.
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Pneumonia/microbiology , Pneumonia/drug therapy , Multiplex Polymerase Chain Reaction , Intensive Care Units , Pneumonia/diagnosis , Critical CareABSTRACT
Objective:This multicenter clinical evaluation analyzed the clinical performance of five fast nucleic acid detection systems for 2019-nCoV.Methods:Clinical performance of the five fast nucleic acid detection reagents approved in China was evaluated in the present study. Fifty-seven throat swabs samples from COVID-19 patients and fifteen throat swabs samples from healthy people were collected from the First Affiliated Hospital of Zhejiang University school of Medicine, Tongji Hospital of Tongji Medical College of HUST, and National Institute of Viral Disease Control and Prevention of CDC to evaluate the positive coincidence rate, negative coincidence rate, total coincidence rate, the detection time and retest rate as well as the relation between positive intensity and positive coincidence rate of the five fast nucleic acid detection systems in November 2020.Results:The positive coincidence rates of the five kits were 92.59% (50/54), 83.64% (46/55), 98.25% (56/57), 94.44% (51/54) and 98.18% (54/55); and the negative coincidence rates were 93.33% (14/15), 93.33% (14/15), 86.67% (13/15), 100% (14/14) and 93.33% (14/15); and the total coincidence rates were 92.75% (64/69), 85.71% (60/70), 95.83% (69/72), 94.20% (65/69) and 97.14% (68/70), respectively. The positive coincidence rate of the five kits reached 100% for the strong-positive (90/90) and medium-positive samples (84/84), but only 82.18% (83/101) for weak-positive samples (cycle threshold value>33), and the retest rate of two kits were 15.28% (11/72) and 12.50% (9/72), which were both higher than 10%. Total time from sample extraction to amplification was between 32.33-65.33 minutes for these five kits.Conclusion:The five fast nucleic acid detection reagents have good performance and can be used as a supplement to routine nucleic acid detection reagents.
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Recombinase polymerase amplification (RPA) is a novel technology for nucleic acid isothermal amplification. It can achieve the rapid amplification and detection of a target gene under 37-42 ℃. This amplification method is highly sensitive, more specific and less instrument-dependent than other existing methods, and it can also integrate multiple detection modes. Therefore, it is especially suitable for applying in low-resource settings and conducting point-of-care tests. Starting from the reaction principles and the experimental design of RPA, this article pointed out some key points when using RPA in a clinical setting. The current development and related problems of RPA were concluded and the various future uses of this method were also prospected.
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Objective:To compare the detection rate of genital Chlamydia trachomatis (CT) DNA between urine and urethral/cervical swab samples. Methods:From December 2018 to December 2019, a total of 1 475 outpatients were collected from sexually transmitted disease clinics in 7 medical institutions, such as Department of Venereology, Guangzhou Institute of Dermatology, including 1 118 males and 357 females. One urethral/cervical swab sample and one urine sample were collected successively from each patient. Real-time fluorescence-based PCR was performed to detect CT DNA in urine and urethral/cervical swab samples, and paired chi-square test was used to compare the positive rate of CT DNA between the 2 kinds of samples. Random- or fixed-effect meta-analysis was conducted for the test of heterogeneity and merging of positive rates of CT DNA in the urine and urethral/cervical swabs among 7 medical institutions.Results:The positive rate of CT DNA in the urine samples was significantly higher than that in the swab samples from 4 medical institutions (all P < 0.05) , while there was no significant difference in the positive rate of CT DNA between the 2 kinds of samples from 3 medical institutions (all P > 0.05) . The heterogeneity ( I2) estimates of the CT-DNA positive rate in urine and swab samples among different medical institutions were 78.6% (95% CI: 55.9% - 89.6%) and 73.7% (95% CI: 43.7% - 87.7%) , respectively; meta-analysis showed that the total merged positive rate of CT DNA in the urine samples was 10.8% (95% CI: 7.2% - 15.9%) , which was significantly higher than that in the swab samples (7.8%, 95% CI: 4.9% - 12.1%; χ2 = 39.2, P < 0.05) . Compared with the swab sample-based CT-DNA detection method, the sensitivity, specificity, positive predictive value, negative predictive value and consistency rate of the urine sample-based CT-DNA detection method were 97.0% (128/132) , 96.3% (1 293/1 343) , 71.9% (128/178) , 99.7% (1 293/1 297) , and 96.3% (1 421/1 475) , respectively. The positive rate of CT DNA in the urine samples from 1 118 male patients was 11.0% (95% CI: 7.2% - 16.5%) , which was significantly higher than that in the swab samples (7.6%, 95% CI: 4.9% - 11.8%; χ2 = 34.3, P < 0.05) . There was no significant difference in the positive rate of CT DNA between the urine (11.9%, 95% CI: 7.7% - 17.9%) and cervical swab samples from 357 female patients (10.4%, 95% CI: 7.6% - 14.0%; χ2 = 3.2, P > 0.05) . Conclusions:The positive rate of CT DNA in urine samples is higher than or similar to that in urethral/cervical swab samples. The urine sample-based CT-DNA detection method has characteristics of convenience, non-invasiveness, painlessness and low cost, and is worthy of clinical promotion.
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Objective@#To evaluate diagnostic performance of Todd-Hewitt (T-H) broth culture method, direct culture method, liquid chromogenic culture method, and loop-mediated isothermal amplification (LAMP) method for screening group B streptococcus (GBS) during late pregnancy.@*Methods@#In the retrospective study, the rectal vaginal secretions samples were collected from pregnant women at 35 to 37 weeks at the obstetrics clinic of Guangzhou Women and Children′s Medical Center affiliated to Guangzhou Medical University during October 2016 to April 2018. For the purposes of clinical evaluation, T-H broth culture was used as the standard reference method, and double-blind trials were used to evaluate diagnostic performance of direct culture method, liquid chromogenic culture method, and LAMP method for screening group B streptococcus during late pregnancy in three research stages. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), coincidence rate and Yoden index for each method were calculated. Also, the level of agreement between each method and T-H broth was assessed using the kappa (k) coefficient.@*Results@#A total of 969 specimens were detected by the T-H enrichment culture method, and 90 were positive (9.3%). The sensitivities from high to low were LAMP method [100% (25/25)], direct culture method [81.5% (22/27), 95%CI:65.8%-97.1%], and liquid color culture method [71.1% (27/38), 95%CI:55.9%-86.2%]. Specificities were direct culture method [100% (282/282)], liquid color culture method [98.1% (455/464), 95%CI:96.8%-99.3%], and LAMP method [94.0% (125/133), 95%CI: 89.9%-98.1%]. The coincidence rates were direct culture method [98.4% (22+282)/309], liquid color culture method [96.0% (27+455)/502], and LAMP method [94.9% (25+125)/158]. The Kappa values of the direct culture method (0.889), LAMP method (0.832) and the enrichment culture method were all ≥0.75, and that of the liquid color culture method was 0.708. The false negative rate of direct culture method was 18.5% (5/27), and no false negative case by LAMP method, but its false positive rate was 6.0% (8/133). The false negative rate and false positive rate of liquid color culture method were 28.9% (11/38) and 1.9% (9/464), respectively.@*Conclusions@#Of the three screening methods compared in this study, only the LAMP method has the advantages in sensitivity, specificity, and coincidence rate compared with T-H enriched culture method, while the others have a certain degree of false negatives rate. The clinical laboratory can introduce these methods based on laboratory facilities and staffing, or refer to the European and American guidelines and combine the recommended antenatal GBS screening method with intrapartum nucleic acid amplification tests to best meet the clinical demands.
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Objective To investigate the clinical value of a new-generation cartridge Xpert MTB/RIF Ultra assay on detection of Mycobacterium tuberculosis(MTB)and rifampin(RIF)resistance.Methods A total of 111 patients from He'nan Provincial Chest Hospital with suspected tuberculosis(TB)and retreated TB were enrolled into this study from March to December 2016,including 33 cases of tuberculosis detection group(CDG)and 78 cases of drug resistant high-risk group(DRG).The sputum samples of patients were collected.The sensitivity and specificity of Xpert MTB/RIF Ultra,sputum smear,solid Lowenstein-Jensen(L-J)culture and mycobacterial growth indicator tube(MGIT)culture for MTB were evaluated.RIF resistance was performed by Xpert MTB/RIF Ultra,traditional phenotypic drug sensitivity test and Xpert MTB/RIF assay.Measurement data were compared using t-test,and categorical data were compared using chi-squared test.Results Using clinical diagnosis result as the standard,in the CDG,the sensitivity of Xpert MTB/RIF Ultra for MTB detection(75.8%)was not significantly different from those of sputum smear(66.7%),L-J culture(63.6%),MGIT culture(75.6%)and Xpert MTB/RIF(66.7%)(x2=0.67,1.15,0.00 and 0.67,respectively,all P>0.05).In the DRG,the sensitivity of Xpert MTB/RIF Ultra(94.9%)was better than those of L-J culture(55.1%)and MGIT culture(80.8%)with statistical significance(x2=32.8 and7.25,respectively,both P <0.05).The sensitivity of Xpert MTB/RIF Ultra was not significantly different from sputum smear(84.6%)and Xpert MTB/RIF(91.0%)(x2=3.41 and 0.39,respectively,both P>0.05).Xpert MTB/RIF Ultra took the shortest time to obtain the final results,which was(1.76±0.18)h and significantly shorter than smear test([5.04±0.49]h),L-J culture([31.67±0.56]h),MGIT culture([22.36±9.68]h),Xpert MTB/RIF([2.00±0.30]h)(t=16.90,31.98,24.38 and 7.05,respectively,all P <0.01).Using culture result as the standard,the sensitivity for MTB detection of Xpert MTB/RIF and Xpert MTB/RIF Ultra were 93.2% and 98.9%,and the specificity of Xpert MTB/RIF and Xpert MTB/RIF Ultra were both 100%.The sensitivity for MTB detection of Xpert MTB/RIF Ultra(52.2%)was significantly better than that of Xpert MTB/RIF(21.7%)in 23 smear-negative pulmonary TB patients with statistical significance(x2=4.98,P=0.025).Using traditional drug susceptibility test as the standard,the sensitivities for RIF resistance detection of Xpert MTB/RIF and Xpert MTB/RIF Ultra in culture-positive TB patients were 90.9% and 93.2%,respectively,and the specificities were 89.5% and 92.9%,respectively.Conclusions Xpert MTB/RIF Ultra has a higher MTB detection rate than Xpert MTB/RIF in smear-negative pulmonary TB patients.In drug-resistant pulmonary TB patient,MTB/RIF Ultra has high sensitivity,and it takes shorter time to detect MTB and RIF resistance.Thus,Xpert MTB/RIF Ultra has a good application prospect in clinical work.
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Objective@#To explore the preliminary application effect of real-time fluorescence recombinase polymerase amplification (RPA) in the detection of Candida albicans.@*Methods@#(1) Candida albicans standard strain and negative control bacteria of Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Candida glabrata standard strains of respectively 1 mL were collected and their DNA were extracted by yeast/bacterial genomic kit. The specificity of polymerase chain reaction (PCR), real-time fluorescent quantitative PCR, and real-time fluorescence RPA in detecting Candida albicans were analyzed. (2) One Candida albicans standard strain and one negative control bacteria of Candida glabrata standard strain were collected, resuscitated, and counted. Candida albicans was diluted 10 times to 1×107 to 1×101 colony-forming unit (CFU)/mL. The DNA of the two bacteria were extracted as experiment (1). The sensitivity of PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA in detecting Candida albicans were analyzed. The number of cycles for amplification curve to reach the threshold in real-time fluorescent quantitative PCR, and time of appearance of specific amplification curve in real-time fluorescence RPA were recorded and compared with the results in PCR. The detection limit and rate of the above-mentioned 3 methods in detecting Candida albicans were analyzed, and the correlation between concentration of Candida albicans in real-time fluorescence RPA and detection time was analyzed. (3) One standard strain of Candida albicans was collected, and the DNA was extracted as experiment (1) and detected by PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA. The total detection time of the above-mentioned 3 methods was recorded, respectively. (4) The DNA of 31 clinical samples of suspected Candida albicans infection and 1 clinical sample of Candida albicans collected from cotton swab were extracted, PCR and real-time fluorescence RPA were carried out, and the positive detection rates of the above-mentioned methods were calculated. The DNA of the clinical samples with positive results in both PCR and real-time fluorescence RPA were extracted by yeast/bacterial genomic kit, chelex-100 boiling method, and repeatedly freeze-thawing with liquid nitrogen method, and real-time fluorescence RPA and PCR were carried out. The negative control bacteria was Candida glabrata in real-time fluorescence RPA, while negative control bacteria in PCR were the same as experiment (1). The positive results in PCR and real-time fluorescence RPA were observed and time for amplification curve to reach the fluorescence threshold in real-time fluorescence RPA was recorded, respectively. Data were processed with linear correlation analysis and t test.@*Results@#(1) Three methods showed positive results in detecting standard strain of Candida albicans, and none of the 5 negative control bacteria showed positive results. (2) As the concentration of bacterial solution of Candida albicans decreased, the number of cycles for the amplification curve to reach the threshold increased in real-time fluorescent quantitative PCR, the time for appearance of specific amplification curve prolonged in real-time fluorescence RPA, and brightness of the gel strip weakened in PCR. None of the negative control bacteria in the above-mentioned 3 detection methods showed corresponding positive results. The detection limit of Candida albicans in real-time fluorescence RPA, PCR, and real-time fluorescent quantitative PCR was 1×101 CFU/mL. There was a significant negative correlation between the concentration of Candida albicans and the detection time in real-time fluorescence RPA (r=-0.95, P<0.01). The positive detection rates of PCR and real-time fluorescent quantitative PCR for Candida albicans of 1×101 to 1×107 CFU/mL were 100%. The positive detection rate of real-time fluorescence RPA for Candida albicans of 1×101 CFU/mL was 78%, and the positive detection rate of real-time fluorescence RPA for Candida albicans of 1×102 to 1×107 CFU/mL was 100%. (3) The total time of PCR, real-time fluorescent quantitative PCR, and real-time fluorescence RPA detection for Candida albicans was 133, 93, and 35 min, respectively. (4) The positive detection rate of real-time fluorescence RPA for 31 clinical samples of suspected Candida albicans infection was 32.26% (10/31), which was slightly lower than 35.48% (11/31) of PCR. Eleven clinical samples showed positive results both in real-time fluorescence RPA and PCR detection. No positive result was observed in the negative control bacteria detected both by real-time fluorescence RPA and PCR. The DNA was extracted by yeast/bacterial genomic extraction kit and chelex-100 boiling method for real-time fluorescence RPA detection. The time for the amplification curve to reach the threshold was (438±13) and (462±12) s, respectively, which was close (t=1.32, P>0.05). The DNA was extracted by repeatedly freeze-thawing with liquid nitrogen method for real-time fluorescence RPA, and the time for the amplification curve to reach the threshold in real-time fluorescence RPA was (584±15) s, which was significantly longer than that in the other 2 methods (t=7.55, 6.39, P<0.01).@*Conclusions@#Real-time fluorescence RPA has advantages of rapid detection, simple operation, high sensitivity, and good specificity in detecting Candida albicans, which is worthy of clinical application.
ABSTRACT
Objective@#To investigate the clinical value of GeneXpert in the rapid diagnosis of rifampicin resistance in tuberculosis and extrapulmonary tuberculosis.@*Methods@#From June 2018 to March 2019, a total of 122 tuberculosis patients admitted to the People's Hospital of Yueqing were selected.Among them, 109 patients with pulmonary tuberculosis and 13 patients with extrapulmonary tuberculosis.GeneXpert MTB/RIF, smear, LJ solid medium, BACTEC MGIT 960 liquid medium four detection methods were used to detect tuberculosis secretion.GeneXpert MTB/RIF, LJ solid medium, BACTEC MGIT 960 liquid medium three detection methods were used to detect extrapulmonary tuberculosis secretion.The sensitivity and specificity of GeneXpert MTB/RIF, smear, LJ solid medium, BACTEC MGIT 960 liquid medium for tuberculosis specimens were detected and compared, and the monitoring results of rifampicin resistance in extracorporeal tuberculosis specimens in culture medium detected by GeneXpert MTB/RIF, LJ solid medium, BACTEC MGIT 960 liquid were observed.@*Results@#The GeneXpert MTB/RIF, smear, LJ solid medium, BACTEC MGIT 960 liquid medium were used to detect 109 cases of tuberculosis, and the detection rates were 94.50%(103/109), 55.04%(60/109), 57.79% (63/109), 61.47%(67/109), respectively.The detection rates of extrapulmonary tuberculosis were 7.69%(1/13), 0.00%(0/13) and 15.38%(2/13), respectively.The sensitivity and specificity of the four methods for the diagnosis of tuberculosis had statistically significant differences(χ2=121.540, 127.610, all P<0.05). The diagnostic efficiency of GeneXpert MTB/RIF was significantly better than smear, LJ solid medium, BACTEC MGIT 960 liquid medium.The results of stratification analysis of rifampicin resistance using GeneXpert MTB/RIF, LJ solid medium and BACTEC MGIT 960 liquid medium showed that there were no statistically significant differences among the three methods and gold standard(χ2=0.750, 0.942, 0.947, all P>0.05).@*Conclusion@#GeneXpert technology has the advantages of simple operation, rapid detection and high detection rate.It has high clinical value for the rapid diagnosis of tuberculosis and extrapulmonary specimens and the detection of rifampicin resistance.
ABSTRACT
Chlamydia trachomatis (CT) is a prevalent pathogen clinically causing trachoma and sexually transmitted diseases. This review presents the progress and application of molecular biology techniques in CT detection according to different types of methodologies, mainly including real-time PCR amplification tests, nucleic acid isothermal amplification tests, PCR-hybridization, sequence analysis and compare their advantages and disadvantages. The recent developments of the point-of-care testing for CT are also briefly introduced in this paper.
ABSTRACT
Chlamydia trachomatis (CT) is a prevalent pathogen clinically causing trachoma and sexually transmitted diseases. This review presents the progress and application of molecular biology techniques in CT detection according to different types of methodologies, mainly including real-time PCR amplification tests, nucleic acid isothermal amplification tests, PCR-hybridization, sequence analysis and compare their advantages and disadvantages. The recent developments of the point-of-care testing for CT are also briefly introduced in this paper.
ABSTRACT
Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRISPR/Cas9),a cluster of regularly spaced short palindromic repeats,is a natural immune defense system for bacteria and archaea to identify themselves and exogenous invading DNA fragments,protecting them from viruses.In recent years,CRISPR/Cas9 has become a revolutionary gene editing tool.Its specific targeted spot-cutting ability also plays an important role in nucleic acid detection,bacterial typing,etc.,and has shown great application potential in the field of medical testing.Based on the latest researches,this paper reviews the progress of CRISPR/Cas9 application in the new techniques of nucleic acid detection,pathogen typing and bacterial evolution in laboratory medicine,and also summarizes the application prospect of CRISPR technology in the field of laboratory medicine.
ABSTRACT
Rapid diagnosis is important for the prevention and control of infectious disease.Point-of-care testing (POCT) technology is simple,mobile,rapid,sensitive and accurate.In recent years,POCT has been widely used in the detection of infectious agents.This article reviews the development of POCT in the diagnosis of infectious diseases,focusing on immuno-chromatographic technology,microfluidic chip technology and loop-mediated isothermal amplification (LAMP) technology.
ABSTRACT
Tuberculosis (TB) is one of the leading causes of adult death in the Asia-Pacific Region, including Indonesia. As an infectious disease caused by Mycobacterium tuberculosis (MTB), TB remains a major public health issue especially in developing nations due to the lack of adequate diagnostic testing facilities. Diagnosis of TB has entered an era of molecular detection that provides faster and more cost-effective methods to diagnose and confirm drug resistance in TB cases, meanwhile, diagnosis by conventional culture systems requires several weeks. New advances in the molecular detection of TB, including the faster and simpler nucleic acid amplification test (NAAT) and whole-genome sequencing (WGS), have resulted in a shorter time for diagnosis and, therefore, faster TB treatments. In this review, we explored the current findings on molecular diagnosis of TB and drug-resistant TB to see how this advancement could be integrated into public health systems in order to control TB.