Detección rápida de Enterobacterias productoras de carbapenemasas en hisopados rectales de pacientes neonatos colonizados / Rapid detection of carbapenemase-producing Enterobacteriaceae in rectal swabs of colonized neonatal patients

Resumen Objetivo: Detectar la presencia de Enterobacterias productoras de carbapenemasas en hisopados rectales de neonatos mediante técnica de nefelometría láser y caracterización del tipo de carbapenemasa mediante test inmunocromatográfico. Materiales y Métodos: Estudio descriptivo de corte transversal. Fueron incluidos 57 neonatos, tamizados al ingreso a UCI, mediante hisopado rectal, procesado por nefelometría laser HB&L Carbapenemase (Alifax®) y caracterización del tipo de carbapenemasa por inmunocromatografía rápida RESIST-3 (Coris BioConcept®). Resultados: Encontramos un alto porcentaje de colonización rectal (22.9%) correspondiente a 13 hisopados positivos y 44 (77.1%) fueron negativos por nefelometría láser. Por VITEK 2® se obtuvo identificación de Klebsiella pneumoniae resistente a carbapenémicos en los 13 aislamientos y el test inmunocromatográfico reveló la presencia de carbapenemasas blaKPC en estos aislamientos. Discusión: Estudios evidencian el aumento de la colonización por microorganismos productores de carbapenemasas en neonatos. Los resultados de este estudio demuestran que un porcentaje significativo de neonatos que ingresan a las Unidades de Cuidado Neonatal se encuentran colonizados con Enterobacterias productoras de carbapenemasas en tracto intestinal. Lo anterior constituye un riesgo potencial para su diseminación y posterior desarrollo de brotes, en donde surge la importancia de implementar estrategias de vigilancia activa como la tamización rectal para la detección oportuna de neonatos colonizados.

Abstract Objective: To detect the presence of carbapenemase-producing Enterobacteriaceae in rectal swabs of neonates by means of laser nephelometry technique and characterization of the type of carbapenemase by immunochromatographic test. Materials and Methods: Descriptive cross-sectional study. 57 neonatal patients were included; They underwent rectal screening upon admission to the ICU, using swabs which were processed by HB&L Carbapenemase laser nephelometry (Alifax®) and characterization of the type of carbapenemase by RESIST-3 rapid immu nochromatography (Coris BioConcept®). Results: We found a high percentage of rectal colonization (22.9%) corresponding to 13 positive swabs and 44 samples (77.1%) were negative by laser nephelome try. Identification of carbapenem-resistant Klebsiella pneumoniae was obtained by VITEK 2® in the 13 isolates and the immunochromatographic test revealed the presence of blaKPC carbapenemases in these isolates. Discussion: Studies show increased colonization by carbapenemase-producing microorganisms in neonates. The results of this study demonstrate that a significant percentage of neonates who enter Neonatal Care Units are colonized with Enterobacteriaceae that produce carbapenemases in the intestinal tract. This constitu tes a potential risk for its spread and subsequent development of outbreaks, where the importance of implementing active surveillance strategies such as rectal screening for the timely detection of colonized neonates arises.

Development of an immunochromatographic strip for detection of Zika virus NS1 antigen / 热带医学杂志

@#Abstract：Objective To develop a colloidal gold immunochromatographic strip ⁃ based method for the rapid detection of Zika virus（ZIKV）NS1 antigen. Methods The gold nanoparticles modified with the anti⁃ZIKV NS1 monoclonal antibody as the detection probe were coated on the glass ⁃fiber pad. The anti ⁃ZIKV NS1 monoclonal antibody and the goat anti ⁃mouse polyclonal antibody were immobilized on a nitrocellulose membrane as the test line and the control line，respectively. In order to achieve critical results，the ratio of the optical density （OD）of the test line to that of the control line was compared. Serial diluted ZIKV NS1 standard antigen was applied to evaluate sensitivity of the immunoassay. The culture supernatant and serum samples for arboviruses（ZIKV，Dengue virus, Japanese encephalitis virus and Chikungunya virus） were utilized to demonstrate the specificity of the method. Results The detection result could read by naked eyes within 20 minutes. The visual cut ⁃off level for the test strip was achieved at 100 ng/mL of the Zika virus NS1 standard antigen. No cross⁃reactions with Dengue virus，Japanese encephalitis virus and Chikungunya virus were observed. The strip could remain good stability within 36 weeks whether stored in 4 ℃ or room temperature（22-25 ℃）. Conclusion Apart from stability， the method was convenient，rapid and specific for ZIKV NS1 antigen，which showed a promising potential in the point of care test and the screening test.

Immunochromatographic Assay for Maximal Residual Limit-based Multiple Quantitative Determination of Triazophos in Agro Products / 分析化学

A novel immunochromatographic assay was developed, which could provide visual evidence of triazophos in agro products, and also could directly identify the safety status by setting visual cut-off limit of detection in maximal residual limit ( MRL) value. Three test lines ( T1, T2, T3) were applied to the nitrocellulose membrane with different concentrations of Triazophos-OVA, and one control line (C) was settled with goat anti mouse IgG antibody. Thereafter, by combining with conjugate pad which immobilized monoclonal antibody labeled with 20 nm Colloidal gold particles, absorbent pad and PVC plate, a chromatographic test strip was assembled. With optimization of sample extraction and solvents selection, the test strips were employed for the determination of triazophos in rice, cabbage and apple. The results revealed that the cut-off limit of detection could reach 0. 005, 0. 01 and 0. 02 μg / mL represented by test line T3, T2 and T1, respectively. After modification, the cut-off limit of detection was resettled to 0. 05, 0. 1 and 0. 2 μg / mL according to the MRL values which enforced by the national standard of GB2763. Using acetonitrile for the sample extraction, the extracts were diluted 10 times or solvent exchanged with equivalent volume by PBS solution, and then tested by strips descripted above mentioned. The two test strips could precisely identified the safety status of agro product with MRL as threshold within 8-12 min. Furthermore, the residues value of triazophos could be quantified by the multiple quantitative test lines. Parallel GC data indicated that the strip had no false negative. This MRL-based multiple quantitative triazophos detection strip would provide a simple, direct, accurate and the most intuitionistic performance for the evaluation of agro product safety.

Immunochromatographic Assay for Detection of Imidaclothiz Based on Upconversion Fluorescence Labeling / 分析化学

A simple,rapid and sensitive upconversion immunochromatographic assay(UICA) was developed to detect imidaclothiz using NaYF4:Yb,Er upconversion nanoparticles(UCNPs) labeled with anti-imidaclothiz monoclonal antibody. The amino-modified UCNPs were conjugated with anti-imidaclothiz monoclonal antibody to prepare the UICA strip,which could realize the quantitative detection of imidaclothiz using a fluorescence photometer with an external 980 nm laser source. The working conditions of the UICA were systematically optimized, and the sensitivity, specificity, precision and accuracy were assessed by the studies of cross-reactivity (CR), spiked recovery and validation with HPLC. Under the optimal conditions (pH 8. 0, 0.3 mol/L NaCl,2.5% methanol and 0.2% PEG2000), the UICA could be completed in 25 min for the detection of imidaclothiz. The half-maximal inhibition concentration (IC50), limit of detection (IC10) and linear range (IC10-IC90) were 97.37 ng/mL,26.30 ng/mL and 26.30-363.08 ng/mL, respectively. The UICA had no CR with the analogues of imidaclothiz except for imidacloprid. The average spiked recoveries were 71.8%-97.2% with the relative standard deviations of 0.7%-10.7% in the matrices of paddy water, soil,pear,peach,wheat,cucumber,tomato and rice. The detection results of UICA for the authentic paddy water and pear samples were consistent with that of high performance liquid chromatography (HPLC).

An enhanced immunochromatographic strip test using colloidal gold nanoparticle-labeled dual-type N proteins for detection of antibodies to PRRS virus

Porcine reproductive and respiratory syndrome (PRRS) is recognized as one of the most important infectious diseases causing serious economic loss in the swine industry worldwide. Due to its increasing genetic diversity, a rapid and accurate diagnosis is critical for PRRS control. The immunochromatographic strip test (ICST) is a rapid and convenient type of immunoassay. In this study, an on-site immunochromatographic assay-based diagnostic method was developed for detection of PRRS virus (PRRSV)-specific antibodies. The method utilized colloidal gold nanoparticle-labeled dual-type nucleocapsid proteins encoded by open reading frame 7. We evaluated 991 field samples from pig farms and 66 serum samples from experimentally PRRSV-inoculated pigs. Based on true PRRSV-specific antibody-positive or

Establishment of Fluorescence Immunochromatographic Assay for Quantitative Detection of Morphine / 中国药学杂志

OBJECTIVE: To establish a high sensitivity method for rapid quantitative detection of morphine in the biological samples including serum, saliva and urine. METHODS: With the immunochromatographic lateral flow strip as reaction method, the luminescent lanthanide europium nanoparticles covalently conjugated with morphine monoclonal antibody were adopted as reporters. The morphine antigen and goat anti-mouse antibody were coated at the nitrocellulose membrane separately as the test line and control line. The strip based on competitive inhibition immunoassay principle was detected by the fluorescent reader for rapid quantitative detection of morphine in the biological samples. RESULTS: After experiment optimization, the improved strip could provide the line range 3-3 000 ng·mL-1; precise quality morphine control materials verified CV<10%. There were no cross reactions with amphetamine, methylamphetamine, ketamine and so on; keep the strips at 37 ℃ for 7 d, the performance of the strips did not decline markedly. CONCLUSION: The preliminary established method shows high linearity, precision, specificity and stability. The method could quantitatively detect the morphine in the biological samples in short time. It is supposed to be applied into the grassroots unit.

Establishment of quantitative fluorescence immunochromatographic assay detection method for heat shock protein 90α(HSP90α) / 中国免疫学杂志

Objective:To establish quantitative a fluorescence immunochromatographic assay detection method for the heat shock protein 90α(HSP90α)in human serum.Methods: Indirect the technology of fluorescence microshers immunochromatographic assay was used to research fluorescent microsphere activation,ensure optimal testing time,determine linearity range,precision,recovery experiments,testing clinical samples and that sort of thing in the fluorescence immunochromatographicassay experiment.Results: In all the reaction conditions,it was determined that the optimal teaction time was 5 minutes,and in the best line range (0.39-100 ng/ml) precision quality control materials of high recovery (30 ng/ml) Intra-assay CV was 8.14%;quality control materials of low recovery (10 ng/ml) Intra-assay CV was 9.26%.With high,medium and low recovery of serum recovery was 100.56%,99.76%,94.1%,separately.Foreign kit(ELISA) for detection of 40 cancer patients clinical serum,the result showed that the correlation was 0.968 5.Conclusion: Establishing the method initially quantitative fluorescence immunochromatographic assay for the heat shock protein 90α(HSP90α)in human serum have high performance and linear,clinic accordance rate also can satisfy the demand of clinic quantitative detection,and will improve hopeful to applied to clinic after apprroved.

Development of an Enhanced Colloidal Gold Immunochromatographic Assay for Detection of Imidaclothiz / 分析化学

An enhanced gold immunochromatographic assay ( GICA ) with simplicity, rapidity and high sensitivity was developed to detect imidaclothiz by using the high affinity between biotin and streptavidin. The 13-nm AuNPs were double-labeled with anti-imidaclothiz antibody and biotinylated DNA, and the 41-nm AuNPs were labeled with streptavidin to prepare an enhanced gold immunochromatographic test strip for imidaclothiz. The working conditions of the strip were systematically optimized, and the sensitivity, specificity, precision and accuracy were assessed by testing the cross-reactivity ( CR) , spiked recovery and validation with high performance liquid chromatography ( HPLC) . Under the optimal conditions, the detection could be completed in 10 min with visual result, and the limit of detection ( LOD ) was 25 ng/mL. The analysis showed no cross-reactivity with analogues of imidaclothiz except for imidacloprid. The detection results of GICA agreed with the spiked concentrations of imidaclothiz at spiked levels of 0 . 05 , 0 . 5 and 5 μg/g in river water, rice, cucumber, tomato, pear, cabbage and apple samples. The detection results of GICA for imidaclothiz in unknown concentration river water and pear samples were consistent with that of HPLC.

Establishment and application evaluation of rapid detection method of Mycoplasma pneuomoniae / 国际检验医学杂志

Objective To prepare the specific monoclonal antibodies(mAb) of Mycoplasma pneumonia(MP) and to establish a colloidal gold rapid detection method of MP by using mAb .Methods The nasopharyngeal swab samples were collected from chil‐dren patients with acute respiratory tract infection ,separated and cultured and performed the MP identification ,MP antigen was pu‐rified ,mAb of MP was prepared ,then the MP colloidal gold test strip was established by using MP mAb .The throat swab sample was collected from the patients with suspected MP infection and detected by using the fluorescent quantitative PCR and colloidal gold test strip .The detection results were observed and statistically analyzed .Results MP strain was successfully isolated and inac‐tivated ,the MP antigen was purified .The mouse was immunized by using this antigen ,19 strians of mAb against MP were prepared by using the hybridoma technique .Among them ,2 strains of mAb with high titer and good specificity(MP‐5 and MP‐19) were se‐lected as the raw materials for preparing the MP colloidal gold rapid test strip .The lowest detection limit was 20 ng .The clinical samples were detected by using the MP colloidal gold rapid test strip and fluorescent quantitative PCR .The results showed that the sensitivity of MP colloidal gold rapid test strip by using this established method was 88 .2% and its specificity was 82 .6% .Conclu‐sion specific mAbs against MP is prepared and the colloidal gold rapid detection method is preliminarily established which provides the help for rapid diagnosis in the patients with MP infection .

Safety issues and new rapid detection methods in traditional Chinese medicinal materials

The safety of traditional Chinese medicine (TCM) is a major strategic issue that involves human health. With the continuous improvement in disease prevention and treatment, the export of TCM and its related products has increased dramatically in China. However, the frequent safety issues of Chinese medicine have become the 'bottleneck' impeding the modernization of TCM. It was proved that mycotoxins seriously affect TCM safety; the pesticide residues of TCM are a key problem in TCM international trade; adulterants have also been detected, which is related to market circulation. These three factors have greatly affected TCM safety. In this study, fast, highly effective, economically-feasible and accurate detection methods concerning TCM safety issues were reviewed, especially on the authenticity, mycotoxins and pesticide residues of medicinal materials.

Clinical Application of Novel Colloidal Gold Immunochromatographic Test Strip for Group B Streptococci / 现代检验医学杂志

Objective To explore the effect of a novel colloidal gold immunochromatographic test strip for detection of group B streptococci (GBS).Methods A total of 202 cases of swab of vagina or neck of uterus were collected,and they were detec-ted by novel strip and control strip to evaluate their clinical applications.Results Sensitivity of novel strip was about 105 CFU/ml and the detection time was about 5 to 8 minutes,and it showed better sensitivity and shorter detection time com-pared with control strip.In the 202 cases of clinical samples,the detection results of 197 cases were in consistent with the control strip,however,the detection results of 5 cases were not in consistent.The positive coincidence rate and negative coin-cidence rate were 97.5% and 97.54% respectively,and the total coincidence rate and Kappa value were 97.52% and 0.948 respectively.The consistency test showed no significant difference between this strip and control strip.Conclusion This method was a effective technology for diagnosing of infection caused by GBS,and had high value in clinical application.

Diagnostic reliability of an immunochromatographic test for Chagas disease screening at a primary health care centre in a rural endemic area

Many patients with Chagas disease live in remote communities that lack both equipment and trained personnel to perform a diagnosis by conventional serology (CS). Thus, reliable tests suitable for use under difficult conditions are required. In this study, we evaluated the ability of personnel with and without laboratory skills to perform immunochromatographic (IC) tests to detect Chagas disease at a primary health care centre (PHCC). We examined whole blood samples from 241 patients and serum samples from 238 patients. Then, we calculated the percentage of overall agreement (POA) between the two groups of operators for the sensitivity (S), specificity (Sp) and positive (PPV) and negative (NPV) predictive values of IC tests compared to CS tests. We also evaluated the level of agreement between ELISAs and indirect haemagglutination (IHA) tests. The readings of the IC test results showed 100% agreement (POA = 1). The IC test on whole blood showed the following values: S = 87.3%; Sp = 98.8%; PPV = 96.9% and NPV = 95.9%. Additionally, the IC test on serum displayed the following results: S = 95.7%; Sp = 100%; PPV = 100% and NPV = 98.2%. Using whole blood, the agreement with ELISA was 96.3% and the agreement with IHA was 94.1%. Using serum, the agreement with ELISA was 97.8% and the agreement with IHA was 96.6%. The IC test performance with serum samples was excellent and demonstrated its usefulness in a PHCC with minimal equipment. If the IC test S value and NPV with whole blood are improved, then this test could also be used in areas lacking laboratories or specialised personnel.

An analysis on results of different detection methods for hepatitis B virus surface antigen / 国际检验医学杂志

Objective To analyze the results of gold labeled immunochromatographic assay (GICA ) ,enzyme-linked immunosor-bent assay (ELISA ) and time resolved fluoroimmunoassay (TRFIA ) detection for hepatitis B virus surface antigen (HBsAg ) . Methods GICA ,ELISA and TRFIA were employed to conduct the HBsAg testing in 11 058 specimens .Results The HBsAg posi-tive rates of GICA ,ELISA and TRFIA detection in 11 ,058 specimens were 15 .52% ,15 .64% and 15 .95% ,respectively ,with no statistically significant difference when pairwise comparison performed (P>0 .05) .In specimens which results of TRFIA quantita-tive detection was 0 .2- <2 .0 ng/mL ,the diagnostic compliance rates of GICA ,ELISA were 25 .0% and 75 .0% ,respectively .Con-clusion The diagnostic compliance rates of GICA ,ELISA detection in specimens with low concentration HBsAg are deceased .

Evaluation of an Immunochromatographic Assay for the Rapid and Simultaneous Detection of Rotavirus and Adenovirus in Stool Samples

BACKGROUND: We evaluated the analytical and clinical performances of the SD BIOLINE Rota/Adeno Rapid kit (SD Rota/Adeno Rapid; Standard Diagnostics, Inc., Korea), an immunochromatographic assay (ICA), for the simultaneous detection of rotaviruses and adenoviruses in human stool samples. METHODS: We tested 400 clinical stool samples from patients with acute gastroenteritis and compared the ICA results with the results obtained by using ELISA, enzyme-linked fluorescent assays (ELFA), PCR, and multiplex reverse transcription-PCR (mRT-PCR). To assess the analytical performance of the SD BIOLINE Rota/Adeno Rapid kit, we determined its detection limit, reproducibility, cross-reactivity, and analytical reactivity for adenovirus subtypes, and performed interference studies. RESULTS: The overall agreement rates among the tested methods were 91.5% for rotavirus and 85.5% for adenovirus. On the basis of mRT-PCR, the overall agreement, positive agreement, and negative agreement rates of the ICA were 95.6%, 100%, and 94.9% for rotavirus, and 94.0%, 71.4%, and 94.8% for adenovirus, respectively. Using the ICA, we detected all the subtypes of adenovirus tested, but the analytical reactivities for adenovirus subtypes were different between the 4 adenovirus detection methods. The high reproducibility was confirmed, and no cross-reactivity or interference was detected. CONCLUSIONS: The SD BIOLINE Rota/Adeno Rapid kit showed acceptable analytical and clinical performances. However, interpretation of adenovirus positive/negative result should be cautious because of different detectability for adenovirus subtypes among adenovirus detection methods.

Evaluation of a Rapid Detection Influenza Virus A Antigens Kit Using Paired Serum Antibody Test

PURPOSE: To evaluate the feasibility for gold immunochromatographic assay (GICA) in rapid detection of influenza virus A infection. MATERIALS AND METHODS: Seventy-three patients were enrolled. All patients contributed nasopharyngeal secretions and paired serum samples. Nasopharyngeal secretions was used for colloidal gold immunochromatographic rapid assay for influenza A virus immediately after the collection of specimen. Paired serum samples were used for the hemagglutination inhibition assay at the Centers for Disease Control and Prevention influenza network laboratory in Beijing. RESULTS: Compare GICA test to hemagglutination inhibition (HI) assay, the Kappa value was 0.402 and the p value in the paired chi2 test was higher than 0.05. Therefore, the difference was not statistically significant. The sensitivity of GICA was 50.0% and the specificity was 90.2%, and the negative predictive value was 90.2%. CONCLUSION: The sensitivity for Influenza A antigen detection by using GICA is relatively low, the specificity is relatively satisfactory.

Evaluation of a New Immunochromatographic Assay Kit for the Rapid Detection of Norovirus in Fecal Specimens

Rapid and accurate detection of norovirus is essential for the prevention and control of norovirus outbreaks. This study compared the effectiveness of a new immunochromatographic assay kit (SD BIOLINE Norovirus; Standard Diagnostics, Korea) and real-time reverse transcription-PCR (RT-PCR) for detecting norovirus in fecal specimens. Compared with real-time RT-PCR, the new assay had sensitivity, specificity, positive predictive value, and negative predictive value of 76.5% (52/68), 99.7% (342/343), 98.1% (52/53), and 95.5% (342/358), respectively. The sensitivity of the assay was 81.8% (18/22) for GII.3 and 75.7% (28/37) for GII.4. None of the 38 enteric virus-positive specimens (3 for astrovirus, 5 for enteric adenovirus, and 30 for rotavirus) tested positive in the cross-reactivity test performed by using this assay. The new immunochromatographic assay may be a useful screening tool for the rapid detection of norovirus in sporadic and outbreak cases; however, negative results may require confirmatory assays of greater sensitivity.

Usefulness of the BACTEC MGIT 960 System for Mycobacterial Culture and TB Ag MPT64 Immunochromatographic Assay to Identify Mycobacterium tuberculosis / 영남의대학술지

BACKGROUND: This study was conducted to evaluate the usefulness of the BACTEC MGIT (Mycobacterium Growth Indicator Tube) 960 system for mycobacteria culture and immunochromatographic assay to identify Mycobacterium tuberculosis (MTB) in positive MGIT culture. METHODS: Mycobacteria-culture-positive cases were retrospectively analyzed from December 2010 to July 2011. The detection rates and the recovery times of the mycobacteria between the Ogawa media and the MGIT were compared. An immunochromatographic assay (ICA) (SD BIO-LINE) was also performed in the positive MGIT culture for identification, and the results were compared with those of the Ogawa media in the Korea National Tuberculosis Association. RESULTS: Among the 261 patients (M:F, 168:93; mean age, 61.6+/-17.16 yrs), 450 specimens (sputa, 365; bronchial washing, 61; and pleural effusion, 24) were found positive with mycobacteria. Mycobacteria were grown both on the MGIT and Ogawa media in 310 cases (68.9%); only on the MGIT in 115 cases (22.6%); and only on the Ogawa media in 25 cases (5.5%) (p<0.05).The recovery time was 28.2+/-8.9 days in the Ogawa media and 11.1+/-5.8 days in the MGIT (p<0.05). Among the 127 cases from the positive MGIT culture, all 92 cases that were confirmed as MTB cases bythe Korea National Tuberculosis Association were identified as MTB by ICA, with 100% sensitivity. CONCLUSION: MGIT increases the detection rate and shortens the recovery time of mycobacteria in clinical respiratory specimens, and the TB Ag MPT64 kit using ICA is useful in identifying MTB in a positive MGIT culture.

Clinical Usefulness of Combined Anti-tuberculosis Antibody Test and Interferon-gamma Release Assay for the Diagnosis of Tuberculosis

BACKGROUND: For the diagnosis of tuberculosis (TB), a variety of tests based on the patients' immune response has been introduced. We evaluated the clinical usefulness of combined anti-tuberculosis antibody (anti-TB Ab) test and Interferon-gamma release assay (IGRA), evaluating humoral and cellular immune response to Mycobacterium tuberculosis, respectively. METHODS: Among patients tested for IGRA, 78 patients diagnosed as TB and treated with anti-TB drug and 80 non-TB patients were included in this study. We used QuantiFERON-TB GOLD (QFT, Cellestis limited, Australia) for IGRA and an immunochromatographic assay, Easy Test TB (ASAN PHARM, Korea), for anti-TB Ab test. RESULTS: The sensitivity, specificity, and positive and negative predictive values of Easy Test TB were 23.1%, 98.8%, 94.7% and 56.8%, respectively. QFT had a significantly higher sensitivity than Easy Test TB (67.9% vs. 23.1%; P<0.05). The agreement between the two assays was poor (69.6%, k=0.190). Of the 18 cases with positive Easy Test TB, six (33%) showed negative QFT results. The combination of Easy Test TB and QFT had a significantly higher sensitivity than single QFT (75.6%, vs. 67.9%; P=0.031). CONCLUSIONS: The combination of Easy Test TB and QFT could be used to aid in a rapid diagnosis and early treatment of TB.

Use of Immunochromatographic Assays for Identification of Mycobacterium tuberculosis Complex from Broth Cultures / 임상검사와정도관리

BACKGROUND: Broth cultures are increasingly used to detect acid-fast bacilli (AFB). Rapid, simple and accurate methods for differentiation of Mycobacterium tuberculosis complex (MTBC) and nontuberculosis mycobacteria from broth cultures are needed. Immunochromatographic assays (ICTs) for identification of MTBC have been developed. METHODS: The abilities of the BD MGIT TBc Identification Test (Becton Dickinson, USA) and the SD Bioline TB Ag MPT64 (Standard Diagnostics, Korea) to detect MTBC were evaluated in 44 AFB-positive broth cultures. The results of 2 ICTs were compared to those of real-time PCR. RESULTS: The BD MGIT TBc Identification Test and the SD Bioline TB Ag MPT64 showed concordant results with real-time PCR by 100% and 97.7%, respectively. The sensitivity of the BD MGIT TBc Identification and the SD Bioline TB Ag MPT64 was 100% for both, and the specificities of those were 100% and 95.2%, respectively. CONCLUSIONS: Both ICTs are rapid methods for identification of MTBC from broth cultures, and the results of ICTs are in accord with those of real-time PCR.

Comparison of Nine Different Qualitative HBsAg Assay Kits / 대한진단검사의학회지

BACKGROUND: Qualitative hepatitis B surface antigen (HBsAg) assay kits are still commonly used in Korea where hepatitis B virus (HBV) infection is endemic. The accurate determination of HBsAg plays a crucial role in the diagnosis and prevention of HBV infection, especially in endemic areas. The aim of this study was to compare the detection sensitivities of 9 qualitative HBsAg assay kits. METHODS: Seven pooled sera with HBsAg concentration ranging from 0.14 IU/mL to 29.96 IU/mL were prepared. The HBsAg concentration of each pooled serum was determined by a quantitative HBsAg assay, Architect HBsAg (Abbott Laboratories, Ireland). The fully automated immunoassay kits included Elecsys HBsAg (Roche Diagnostics, Germany) and Immulite 2000 HBsAg (DPC, USA) and the rapid tests included 5 immunochromatographic assay (ICA) kits and 2 reverse passive hemagglutination assay (RPHA) kits. RESULTS: Elecsys HBsAg (Roche Diagnostics) showed positive result in pooled serum with HBsAg concentration of 0.14 IU/mL, but Immulite 2000 HBsAg (DPC) showed negative result in the same concentration. Although ICA kits showed variable results among different assay kits, all of them showed negative results in pooled sera with HBsAg concentration of < or =1.89 IU/mL. Two RPHA kits showed negative results in pooled sera with HBsAg concentration of < or =7.98 IU/mL. CONCLUSIONS: Although ICAs were more sensitive than RPHAs, they had variable sensitivities for HBsAg and were less sensitive than the automated immunoassay kits. Therefore, ICAs and RPHAs should be used with caution in the screening tests for HBsAg and their sensitivities need to be improved.