BD ProbeTec ET System Research Articles

Five Years' Evaluation of the BD ProbeTec System for the Direct Molecular Detection of Mycobacterium tuberculosis Complex in Respiratory and Nonrespiratory Clinical Samples.

In this study, Mycobacterium tuberculosis complex was detected by BD ProbeTec ET system in 4716 respiratory and 167 nonrespiratory samples [mostly (98%) smear negative). Sensitivity, specificity, positive and negative predictive values were 81.8%, 98.3, 85.1 and 97.9 for respiratory and 100%, 96.2, 64.7 and 100, for nonrespiratory samples, respectively. Among 149 (3.1%) ProbeTec DTB positive and culture negative samples, 72 (65 respiratory and seven nonrespiratory) (48.3%) were recovered from the patients who were evaluated as having TB infection. The system has been found as useful in early diagnosis of tuberculosis infection in association with the clinical, radiological and histopathological findings.

Comparison of Culture, Real-Time DNA Amplification Assay and Ehrlich-Ziehl-Neelsen for Detection of Mycobacterium tuberculosis.

Mycobacterium tuberculosis is still a substantial health problem universally. Although culture is the gold standard method, reliable, rapid and new methods are required for effective struggle with disease. We retrospectively compared the results of Ehrlich-Ziehl-Neelsen (EZN) stain and real-time DNA amplification assay (BD ProbeTec ET system) with culture. Retrospective study. A total of 703 samples, 182 pulmonary and 521 extra pulmonary, collected from 630 patients between May 2008 and February 2011 were evaluated. Culture was considered the gold standard. For pulmonary specimens, sensitivity, specificity, positive predictive and negative predictive values of BD ProbeTec ET and EZN were calculated to be 100%, 98.8%, 87.5%, 100% and 71.4%, 98.8%, 83.3%, 97.6%, respectively. For extra pulmonary specimens, sensitivity, specificity, positive predictive and negative predictive values of BD ProbeTec ET and EZN were calculated to be 80%, 98.7%, 76.9%, 98.9% and 24%, 98.3%, 42.8%, 96.2%, respectively. According to these results, we suggest that the BD ProbeTec ET system is more reliable than EZN. In addition, the BD ProbeTec ET system produces faster results. Based upon these results, we consider that the BD ProbeTec ET system may be employed in the diagnosis of M. tuberculosis.

Bacterial infections of the lower genital tract in fertile and infertile women from the southeastern Poland

The objective of the study was to investigate the detection rates of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum, Gardnerella vaginalis, Escherichia coli, Streptococcus agalactiae and Enterococcus faecalis, showing no clinical signs of an ongoing, acute inflammatory state of the vagina and/or the cenrvix, in fertile and infertile women. The study encompassed 161 women, including 101 women treated for infertility and 60 fertile women who had already given birth to healthy children. The material for the presence of C. trachomatis, N. gonorrhoeae, M. genitalium, M. hominis and U. urealyticum was collected from the cervical canal and analyzed by PCR. Furthermore, BD ProbeTec ET system was used to detect C. trachomatis infection. Vaginal swabs were collected for classification of bacterial vaginosis and aerobic vaginitis and assessed according to the Nugent score, as well as by traditional culture methods. U. urealyticum was identified in 9% of the infertile women and in 8% of controls. Presence of M. hominis was demonstrated only in the former (4%) and C. trachomatis only in latter (3%). N. gonorrhoeae and M. genitalium were not found in any of the examined women. The frequency of aerobic vaginitis in both groups was estimated at 12%. There were 7% bacterial vaginosis cases in the study group, and none in the control group (p=0.0096). Despite having no symptoms of an ongoing acute inflammation of the reproductive tract, many women may experience permanent or periodic shifts of equilibrium of the vaginal and/or cervical microflora. BV develops more frequently in infertile patients when compared to the fertile women.

Chlamydia trachomatis in fallopian tubes of women undergoing laparoscopy for ectopic pregnancy

To study whether Chlamydia trachomatis is absent or persists in a latent state in the fallopian tube at the time of laparoscopic salpingectomy for tubal ectopic pregnancy (EP). We examined tissue of the fallopian tubes for the presence of C. trachomatis from women who underwent laparoscopic salpingectomy for EP. Presence or absence of C. trachomatis was assessed using both Probe Tec ET (define Tec and ET please) and real-time polymerase chain reaction (PCR) (Ausdiagnositic STD 6 assays) DNA amplification. Fresh tubal tissue from 17 women with histological confirmation of EP was examined in a hospital setting for the presence of C. trachomatis. The presence of C. trachomatis DNA was confirmed by PCR using a commercial test (BD ProbeTec ET System), and a real-time enhanced PCR able to detect few copies of the organism. Chlamydia DNA was detected in 0/16 tubal specimens, and in one case, the PCR analysis was not possible for presence of inhibitors. We did not find any evidence of latent infection of C. trachomatis in the fallopian tube at the time of laparoscopic salpingectomy for EP in our study. Although the numbers are small, our results suggest that EP can be considered a late complication of the tubal damage resulted from a previous acute Chlamydia infection and that EP may not be related to a latent persistence of Chlamydia in the fallopian tube.

Effectiveness of the BDProbeTec ET system for detection of Mycobacterium tuberculosis complex in sputum and bronchoalveolar lavage specimens

OBJECTIVE: The diagnostic efficacy of the BDProbeTEC ET Mycobacterium tuberculosis (MTB) complex direct detection assay (DTB) performed on bronchoalveolar lavage (BAL) specimens and sputum smears was compared with acid-fast bacilli (AFB) smear microscopy. METHOD: AFB smear microscopy, DTB and culture results of 286 patients with pulmonary tuberculosis were retrospectively reviewed. A total of 120 patients provided expectorated sputum samples, and 166 patients provided BAL specimens. Culture results and clinical diagnosis were used as gold standards. RESULTS: The sensitivity and specificity of the DTB assay in detecting MTB in sputum specimens was significantly higher compared to AFB smear microscopy (83.7% and 82.4%, vs. 75.6%, and 41.2%, respectively). The sensitivity and specificity of the DTB assay in detecting MTB in sputum samples was 77.2% and 100% compared to clinical diagnosis, while AFB smear had a sensitivity and specificity of 70.3% and 26.3%, respectively. Compared to culture, DTB had a sensitivity and specificity of 82.8% and 93.2%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 41.9% and 87.7%, respectively. Compared to clinical diagnosis, DTB had a sensitivity and specificity of 67.2% and 100%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 34.8% and 79.5%, respectively. CONCLUSIONS: The superior performance of the DTB assay relative to AFB smear microscopy makes it a valuable tool to enable early diagnosis of MTB, thereby improving patient care and reducing transmission.

Effectiveness of the BDProbeTec ET system for detection of Mycobacterium tuberculosis complex in sputum and bronchoalveolar lavage specimens

ObjectiveThe diagnostic efficacy of the BDProbeTEC ET Mycobacterium tuberculosis (MTB) complex direct detection assay (DTB) performed on bronchoalveolar lavage (BAL) specimens and sputum smears was compared with acid-fast bacilli (AFB) smear microscopy. MethodAFB smear microscopy, DTB and culture results of 286 patients with pulmonary tuberculosis were retrospectively reviewed. A total of 120 patients provided expectorated sputum samples, and 166 patients provided BAL specimens. Culture results and clinical diagnosis were used as gold standards. ResultsThe sensitivity and specificity of the DTB assay in detecting MTB in sputum specimens was significantly higher compared to AFB smear microscopy (83.7% and 82.4%, vs. 75.6%, and 41.2%, respectively). The sensitivity and specificity of the DTB assay in detecting MTB in sputum samples was 77.2% and 100% compared to clinical diagnosis, while AFB smear had a sensitivity and specificity of 70.3% and 26.3%, respectively. Compared to culture, DTB had a sensitivity and specificity of 82.8% and 93.2%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 41.9% and 87.7%, respectively. Compared to clinical diagnosis, DTB had a sensitivity and specificity of 67.2% and 100%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 34.8% and 79.5%, respectively. ConclusionsThe superior performance of the DTB assay relative to AFB smear microscopy makes it a valuable tool to enable early diagnosis of MTB, thereby improving patient care and reducing transmission.

Genital and Extra-genital Screening for Gonorrhoea using the BD Probetec ET System with an In-house PCR Method Targeting the porA Pseudogene as Confirmatory Test

Diagnosing gonorrhoea from extra-genital as well as genital sites is important in managing this sexually transmitted disease. In this study we evaluated a screening procedure for Neisseria gonorrhoeae (GC) from all sample sites in a low-prevalence setting. A total of 69,252 specimens submitted for Chlamydia trachomatis testing were also examined for GC on the BD Viper™ platform using the BD Probetec ET system. In order to avoid false-positive results all GC BD reactive samples were re-tested using a PCR method with the porA pseudogene as target. Using this method we screened 170% more samples for GC than in the previous year, in the same population, and diagnosed more than twice as many GC-positive episodes. The BD system can be used successfully to screen extra-genital as well as genital specimen types for GC in a low-prevalence area if it is combined with a validated confirmatory PCR test.

P3-S1.30 Successful use of non-invasive self obtained glans/meatal dry FLOQSwabs (COPAN) for CT/NG detection with the BD ProbeTec ET assay in Northern Italy

BackgroundIncreasing Chlamydia trachomatis (CT) rates and ever-present Neisseria gonorrhoeae (NG) infections worldwide in women have led to the consideration of targeted male CT/NG screening programs in order to address the...

Abdominal Tuberculosis in Adult: 10-Year Experience in a Teaching Hospital in Central Taiwan

Tuberculosis (TB) is an important communicable disease worldwide. The clinical presentation of abdominal TB often mimics various gastrointestinal disorders and may delay accurate diagnosis. In this study, we conducted a 10-year retrospective study to investigate the clinical manifestations, treatment responses and outcomes of abdominal TB. This retrospective study recruited patients presenting between January 1998 and December 2007; all patients ≥ 18 years of age with a diagnosis of abdominal TB were enrolled. Patient charts were thoroughly reviewed and clinical specimens were processed in the laboratory using the BBL MycoPrep System and BACTEC MGIT 960 Mycobacterial Detection System. Mycobacterium tuberculosis complex was confirmed by acid fast stain and the BD ProbeTec ET System. During the study period, 34 patients were diagnosed with abdominal TB. The mean age was 55+18 years. Fourteen patients (41%) had no risk factors; however, 20 patients (59%) had at least one risk factor. Abdominal pain (94.1%), abdominal fullness (91.2%), anorexia (88.2%) and ascites (76.5%) were the most common presenting symptoms. The peritoneum (88%) was the most commonly involved site. Patients with risk factors such as liver cirrhosis, end-stage renal disease and diabetes mellitus had a higher positive rate of acid-fast stain and mycobacterial culture from abdominal specimens (p = 0.02 and 0.05, respectively). The crude mortality rate was 9% and the attributed mortality rate was 3%. In an endemic area like Taiwan, regardless of whether a patient has risk factors for TB, abdominal TB should be seriously considered as a differential diagnosis when a patient presents with gastrointestinal symptoms and unexplained ascites.

The prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae in the endocervical swab specimens of symptomatic, asymptomatic and infertile women in Turkey

To investigate C. trachomatis and N. gonorrhoeae prevalence in three different female populations in Turkey. A total of 370 women, 170 symptomatic, 100 asymptomatic, and 100 infertile, were included. Of the endocervical specimens collected from all women using a Dacron swab, the first one was taken to Stuart's transport medium to culture, while the second one was transferred onto slides to perform direct fluorescent antibody test (DFA) and Gram staining, and the third specimen was used for Becton Dickinson BDProbeTec ET system (BDPT). C. trachomatis was detected in 5.16% of symptomatic, 1.11% of asymptomatic, and 2.15% of infertile women with BDPT. Sensitivity and specificity of the DFA test were 72.73 and 97.85%, respectively. N. gonorrhoeae was detected in 2.42% of symptomatic and in 1.02% of infertile women. N. gonorrhoeae was not detected in any asymptomatic women. In N. gonorrhoeae-positive patients, sensitivity and specificity of culture were 60 and 100%, respectively, while they were 80 and 100% for BDPT. Prevalence of N. gonorrhoeae and C. trachomatis was detected to be low in Turkish women, and the difference between the groups was not significant. Both agents were more prevalent in subjects over 25 years of age.

Incidence of Chlamydia trachomatis infections in the provinces of Novara and VCO: one year of observations

Chlamydia trachomatis infections represent the most common sexually transmitted diseases.The lack of growth of these microorganisms on common media and the roundabout research by immunofluorescence, has meant that, until now, these special-lived intracellular microorganisms have played a role probably underestimated in cases of infections affecting the sexual organs.The introduction of molecular biology has made possible their research in a much more simple, reliable and standardized methods. The study was carried out on endocervical samples, male urethral swabs and urine samples of men and women, determining the C. trachomatis DNA amplified using the BD ProbeTec ET system. This system uses technology SDA (Strand Displacement Amplification - Elongationcrowding of the blanks). The study was conducted from June 2008 to june 2009. Symptomatic and asyntptomatic patients residents in the provinces of Novara and the Verbano-Cusio-Ossola were considered. In this period 784 determinations were made in molecular biology. Chlamydia trachomatis was found in 26 cases equal to a percentage of 3.32%. While considering these preliminary data, however, we can estimate the rate of detection of C. trachomatis as a good starting point, because we have the impression that improved procedures particularly relate to the techniques for sampling and for storage and transport of the sample, can undoubtedly lead to much higher percentages.

Detection of Neisseria gonorrhoeae and Chlamydia trachomatis in pharyngeal and rectal specimens using the BD Probetec ET system, the Gen-Probe Aptima Combo 2 assay and culture

Objectives: This study compared the sensitivity and specificity of culture and two nucleic acid amplification tests (NAATs): the BD Probetec ET system (PT) and the Aptima Combo 2 (AC2) in...

Evaluation of the BD ProbeTec ET system for the direct detection of Mycobacterium tuberculosis from clinical samples

Early detection of disease caused by members of the Mycobacterium tuberculosis complex (MTBC) is essential in controlling transmission of tuberculosis. Clinical evaluation of the BD ProbeTec ET system for the direct detection of MTBC organisms in clinical specimens is carried out by comparing results obtained with conventional liquid culture and reference laboratory identification. In 186 specimens (159 respiratory, 27 non-respiratory), the BD ProbeTec ET assay detected eight out of 11 MTBC culture-positive specimens, with overall sensitivity, specificity, positive predictive value and negative predictive value of 85%, 100%, 100% and 99%, respectively. The data show that the BD ProbeTec ET assay is a highly sensitive and specific technique, and gives an accurate result from a clinical specimen within three to four hours.

Performance assessment of the Capilia TB assay and the BD ProbeTec ET system for rapid culture confirmation of Mycobacterium tuberculosis

Because of the increasing numbers of nontuberculous mycobacterial isolates from clinical specimens, rapid and accurate methods for culture confirmation of Mycobacterium tuberculosis are urgently needed. The study evaluated the performance of the Capilia TB immunochromatographic assay (TAUNS, Numazu, Japan) for culture confirmation of M. tuberculosis using 242 culture-positive liquid media in 2 mycobacterial laboratories from November 2005 to February 2006. Among the 242 samples, 183 were also tested with the BD ProbeTec ET (CTB) assay (Becton Dickinson, Sparks, MD). The results of both assays were compared to the culture results and to each other. The overall sensitivity and specificity of the Capilia TB assay were 98.6% and 97.9%, respectively, and for the CTB assay were 97.3% and 97.1%, respectively. The positive and negative predictive values for the Capilia TB assay were 98.6% and 97.9%, respectively, and for the CTB assay were 98.2% and 95.8%, respectively. Among the 183 samples tested with both assays, 8 had discrepant results, including Capilia-TB-false-positive in 2, CTB-false-positive in another 2, CTB-false-negative in 2, Capilia TB-false-negative in 1, and both assays with false-negative results in the remaining one. This study demonstrated that the Capilia TB assay has a similar diagnostic value with the CTB assay. In addition, with the immunochromatographic method, it is less time-consuming and does not require other laboratory equipment.

Evaluation of the BD ProbeTec ET System for Direct Detection of Mycobacterium bovis in Veterinary Specimens

We describe the application of the BD ProbeTec ET direct tuberculosis system for the detection of Mycobacterium bovis in bovine and cervine lymph node tissues. Compared to traditional culture, the overall sensitivity, specificity, and positive and negative predictive values of the BD ProbeTec were 87, 100, 100, and 87%, respectively.

R2190 Comparison of real-time PCR and BDProbeTec ET system for rapid diagnosis of tuberculosis patients

R2190 Comparison of real-time PCR and BDProbeTec ET system for rapid diagnosis of tuberculosis patients

A Fast Real-Time Polymerase Chain Reaction Method for Sensitive and Specific Detection of the Neisseria gonorrhoeae porA Pseudogene

Ever since the advent of molecular methods, the diagnostics of Neisseria gonorrhoeae has been troubled by false negative and false positive results compared with culture. Commensal Neisseria species and Neisseria meningitidis are closely related to N. gonorrhoeae and may cross-react when using molecular tests comprising too-low specificity. We have devised a real-time polymerase chain reaction (PCR), including an internal amplification control, that targets the N. gonorrhoeae porA pseudogene. DNA was automatically isolated on a BioRobot M48. Our subsequent PCR method amplified all of the different N. gonorrhoeae international reference strains (n = 34) and N. gonorrhoeae clinical isolates (n = 176) but not isolates of the 13 different nongonococcal Neisseria species (n = 68) that we tested. Furthermore, a panel of gram-negative bacterial (n = 18), gram-positive bacterial (n = 23), fungal (n = 1), and viral (n = 4) as well as human DNA did not amplify. The limit of detection was determined to be less than 7.5 genome equivalents/PCR reaction. In conclusion, the N. gonorrhoeae porA pseudogene real-time PCR developed in the present study is highly sensitive, specific, robust, rapid and reproducible, making it suitable for diagnosis of N. gonorrhoeae infection.

Performance Assessment of the DR. MTBC Screen Assay and the BD ProbeTec ET System for Direct Detection of Mycobacterium tuberculosis in Respiratory Specimens

The performance of the DR. MTBC PCR-based assay and the BD ProbeTec ET Mycobacterium tuberculosis Complex Direct Detection (DTB) assay for the direct detection of Mycobacterium tuberculosis was evaluated using 1,066 consecutive clinical respiratory samples collected from 494 patients who did not have old cases of pulmonary tuberculosis and were not receiving antituberculosis treatment at National Taiwan University Hospital from January to February 2005. The results of both assays were compared to the "gold standard" of combined culture results and clinical diagnosis. The overall sensitivity and specificity of the DR. MTBC Screen assay were 56.6% and 98.9%, respectively, and of the DTB assay were 63.2% and 98.4%, respectively. The positive and negative predictive values for the DR. MTBC Screen assay were 84.5% and 95.4%, respectively, and for the DTB assay were 81.7% and 96.0%, respectively. The DR. MTBC Screen assay produced 11 false-positive results for 11 patients, including three samples yielding non-M. tuberculosis mycobacteria (one each for M. abscessus, a mixture of M. abscessus and M. chelonae, and unidentified non-tuberculosis mycobacteria). The DTB assay produced 15 false-positive results for 13 patients, including five samples from four patients yielding non-tuberculosis mycobacteria (two for M. abscessus, one for a mixture of M. abscessus and M. chelonae, and two for unidentified non-tuberculosis mycobacteria). This study demonstrated that the DR. MTBC Screen assay has a similar diagnostic value but fewer false-positive results than the DTB assay for respiratory specimens.

子宮頸管および咽頭擦過検体, 尿検体に対するSDA法を原理とする新しい核酸増幅法を用いた<I>Chlamydia trachomatis</I>および<I>Neisseria gonorrhoeae</I>の検出

The performance of a real-time DNA amplification assay, BD ProbeTec ET System (BDPT, BD Diagnostic Systems), to detect Chlamydia trachomatis and Neisseria gonorrhoeae on endocervical and oropharyngeal samples was evaluated. After obtaining informed consent, 364 endocervical, 363 urine and 247 oropharyngeal specimens were collected from 307 cases. The overall agreement rate of the BDPT and Amplicor (AMP, Roche) assays for the detection of C. trachomatis and N. gonorrhoeae in endocervical samples was 99.2% (361/364) for C. trachomatis and 99.5% (362/364) for N. gonorrhoeae. Assay of oropharyngeal swabs by the BDPT yielded 21 C. trachomatis positives, and 19 of them were C. trachomatis negative by the DNA probe assay (Gen-Probe PACE). The AMP assay showed that 16/19 (84.2%) of the BDPT +/DNA probe - samples were positive. The BDPT also yielded 21 N. gonorrhoeae positives, 15 of which were negative with the DNA probe. Additional testing showed that all 15 BDPT +/DNA probe - samples were positive by the established nested PCR method. Our data suggest that the performance of the BDPT is comparable to that of AMP for detection of C. trachomatis and N. gonorrhoeae in endocervical swab samples and that it may be a useful method for detecting of C. trachomatis and N. gonorrhoeae in oropharyngeal samples clinically.

Cryptic-Plasmid-Free Gonococci May Contribute to Failure of cppB Gene-Based Assays To Confirm Results of BD ProbeTEC PCR for Identification of Neisseria gonorrhoeae

We note the recent article by Koenig et al. ([3][1]) which describes discordance between results obtained with the BD ProbeTEC ET System (BDPT) and a cppB gene-based PCR assay for the detection of Neisseria gonorrhoeae . Overall, 22.6% of BDPT-positive assays were not confirmed by the cppB gene-