Immunochromatographic Membrane Test Research Articles

Identifying pneumococci in parapneumonic pleural effusion: Is there a role for culture-independent methods?

To evaluate culture-independent procedures (immunochromatography and quantitative polymerase chain reaction [qPCR]) in the detection and susceptibility of Streptococcus pneumoniae directly from culture-negative pleural fluid (PF) in children. Detection of S. pneumoniae in PF of children with parapneumonic effusion and/or empyema by using two culture-independent methods: an immunochromatographic membrane test (IMT) which identifies the pneumococcal C antigen, and a real-time PCR test to detect pneumococcal genes lytA and pbp2b, a marker of susceptibility of β-lactam agents, in PF samples. We tested 36 PF specimens and recorded the previous use of antimicrobials. In the final analysis, 34 samples were included. IMT and qPCR presented positive results in 23 (67.6%) and 24 (70.6%) of the samples, respectively, showing a moderate agreement (k = 0.518) between the two methods. From the 36 children included, 34 (94.4%) had antibiotic data available by the time when PFs were collected. Thirty-four (100%) children had been given treatment before PF sampling, with 33 (97%) receiving β-lactam antibiotics administered empirically. Of the 24 lytA real-time positive samples, 21 (87.5%) were also positive for pbp2b, a marker of β-lactam susceptibility. The reduced sensitivity of culture for pneumococcal detection can be improved through the addition of IMT and qPCR analysis. The utility of qPCR combining detection of lytA and a marker of β-lactam susceptibility should be explored further.

Algorithm for the diagnosis of Helicobacter pylori with peri-implantitis

The leading etiologic factor in the development of peri-implantitis is microorganisms, which, due to the development of the infectious process, cause resorption of bone tissue directly adjacent to the implant, followed by its disintegration and removal. The aim of this study was to develop reliable and informative algorithms for diagnosing the development of peri-implantitis, which will maximally include safe and affordable methods. Objects and methods. Patients aged 20 to 48 years were examined, with a partial secondary edentia. All patients were randomly divided into two groups, comparable by demographic, nosological indicators. The first group consisted of 248 patients with osseointegrated implants, the second group consisted of 26 individuals which based on examination of the clinical picture and the results of X-ray, verified the diagnosis of peri-implantitis. A phased examination was conducted. To determine antibodies to Helicobacter pylori in the saliva, the diagnostic immunochromatographic membrane test method of the test cassette was used in patients of both groups in accordance with the method proposed by the authors. The second stage was the cytological examination of the contents from the bone cavity after removal of the implant and the third stage was the release of Helicobacter pylori DNA in the saliva. Results and discussion. A detailed result of analysis of patient’s examination made it possible to establish the following. Parameters of antibodies to HP in the saliva during the immunochromatographic test revealed the presence of antibodies to HP in 37 (15%) patients of the first group with osseointegrated implants and in 26 (100%) patients of the second group with peri-implantitis. The microbiological composition in the cytological study with peri-implantitis is presented: mixed and coccal flora in 4 patients (10%), fungi in 3 patients (11%), Helicobacter pylori in 24 patients (93%), lymphoid elements, erythrocytes and leukocytes in 26 patients (100%). A comparative evaluation of the results of the polymerase chain reaction in patients of the two groups showed that a positive result (the presence of Helicobacter pylori DNA) in the first group was detected in 20 patients — 23% of the observations. In the second group, a positive PCR test was determined in 26 patients, which was 100% of the observations. Each of the laboratory methods for detecting HP has its advantages and disadvantages, as well as its sensitivity and specificity. Numerous comparative studies have shown that the results obtained using different methods are not always identical. In this case, the result should be considered positive or negative when the indicators of all applied methods of research coincide. Conclusion. The obtained results are the basis for the conclusion about the presence of a definite relationship of the pathological inflammatory process in the bone tissue of the jaw directly adjacent to the dental implant and the character of Helicobacter pylori carriage in the observed patients.

Identification of Prostate‐Specific Antigen and Spermatozoa from a Mixture of Semen and Simulated Gastric Juice

The detection of prostate-specific antigen (PSA) and visualization of spermatozoa from forensic-type samples containing semen exposed to simulated gastric juice was investigated as a support for forensic practice. Samples of simulated gastric juice mixed with semen were prepared and incubated for up to 4 h at 37 degrees C. Samples were deposited on cotton cloth and on ceramic plates and allowed to dry. The samples were examined for the presence of PSA using the Seratec PSA Semiquant immunochromatographic membrane test. Microscope slides were prepared, stained, and analyzed for spermatozoa. Spermatozoa were detected in all samples, and PSA was detected on neat samples and on samples from the ceramic plate after incubation for up to 4 h. PSA was not detected in the samples deposited on cotton cloth at incubation times greater than 15 min. This may serve as a support for examinations performed when vomit or vomit-stained evidence is submitted for analysis.

Detection of Legionella pneumophila serogroup 1 antigen in respiratory samples using an immunochromatographic membrane test

The immunochromatographic membrane test (ICT) efficacy of Legionella antigen detection (Binax Now Legionella®) was evaluated using respiratory samples, including bronchial washings (44 cases) and sputum (128 cases), from suspected Legionella pneumonia patients. The ICT results using respiratory samples agreed well with isolation of L. pneumophila SG1 and ICT using urines.

Streptococcus pneumoniae thoracic empyema in children: rapid diagnosis by using the Binax NOW immunochromatographic membrane test in pleural fluids

Aim To evaluate an immunochromatographic membrane test for Streptococcus pneumoniae antigen (Binax NOW, Inverness medical France) applied to pleural fluid samples. Methods Binax NOW was applied to the pleural fluids of 69 children with thoracic empyema, in comparison with conventional culture and molecular techniques. Results Binax NOW was positive on all 15 pleural fluid samples that yielded S. pneumoniae in culture, on two samples that yielded S. oralis and S. salivarius in culture and on 34 culture-negative samples. Fifteen of these 34 culture-negative samples were retrospectively tested by PCR methods, and 14 were shown to contain S. pneumoniae DNA. Thus, S. pneumoniae was identified by culture in 22% of samples and by Binax NOW in 69% of samples. Conclusion Binax NOW may thus be useful for rapid diagnosis of S. pneumoniae thoracic empyema.

Evaluation of the Binax NOW Streptococcus pneumoniae urinary antigen assay in intensive care patients hospitalized for pneumonia

To evaluate the diagnostic performance of Binax Now S. pneumoniae urinary antigen rapid immunochromatographic membrane test (ICT) for patients with suspicion of community-acquired pneumonia hospitalized in intensive care and to assess the impact of prior antibiotics on its diagnostic performance. Retrospective study in a medicosurgical ICU in a 700-bed general hospital. Charts of patients with ICT performed (result blinded) were reviewed between May 2002 and July 2004. ICT has been performed in 140 of the 1,006 patients hospitalized in the unit; two-thirds had received antibiotics prior to admission. Diagnosis of pneumonia was made according to usual criteria. All patients had at least one microbiological test. Pneumonia diagnosis confirmed in 108 patients including 32 pneumococcal. ICT was positive in 23 of 32 patients with pneumococcal pneumonia, in 11 of 108 without, and in none of the 32 patients without pneumonia, resulting in sensitivity, specificity, and positive and negative predictive values of, respectively: 72%, 90%, 68% and 92%. Positive likelihood ratios were comparable among patients with or without prior antibiotics (respectively 6 and 12 for 7 in the overall population). This first clinical evaluation of ICT in intensive care patients hospitalized for suspicion of community-acquired pneumonia, demonstrated performance in accordance with published data even in the case of prior antibiotics. Its clinical interest and impact on antibiotics policy remain to be refined.

Evaluating the Use of a Streptococcus pneumoniae Urinary Antigen Detection Kit for the Management of Community-Acquired Pneumonia in Japan

Background: The urinary antigen detection kit for Streptococcus pneumoniae was tested. Objectives: It was our aim to evaluate the usefulness of the immunochromatographic membrane test by doing a large prospective study of community-acquired pneumonia (CAP) in Japan. Methods: We prospectively evaluated the use of the S. pneumoniae urinary antigen detection kit and analyzed the treatment and clinical effect seen in patients with positive test kit results. One hundred and fifty-six patients with CAP admitted to our hospital between October 2001 and September 2003 were evaluated. Results: In 49% of these CAP patients, the causative microorganisms were isolated. S. pneumoniae was suspected to be the causative microorganism in 15%, but positive results of the urinary antigen detection kit indicated S. pneumoniae to be a probable microorganism in 28%, even though antibiotics had previously been administered to half of the patients. The kit was particularly useful for diagnosing patients with poor quality sputum in whom antibiotics treatment nevertheless had to be selected. Antibiotics appropriate for S. pneumoniae (mainly penicillin) were given. The treatment was found to have excellent clinical results in 89% of the CAP patients. Conclusions: The S. pneumoniae urinary antigen detection kit was considered to be useful in selecting treatment since there was a high level of clinical effectiveness when the most suitable antibiotics were immediately administered to positive patients. The use of the S. pneumoniae urinary antigen kit is rapid and simple compared with conventional microbiological procedures.

Semi-quantitative analysis of Streptococcus pneumoniae urinary antigen: Kinetics of antigen titers and severity of diseases

Detection of urinary antigen by a rapid immunochromatographic membrane test (Binax NOW) was widely accepted as a powerful tool for diagnosis of Streptococcus pneumoniae pneumonia. This is a qualitative kit, so the value of quantitative analysis of urinary antigen, especially correlation of antigen titers and severity of diseases, remained to be determined. We examined semi-quantitative antigen titer in urines collected from urinary antigen-proven S. pneumoniae pneumonia on admission, and analyzed the kinetics of antigen titer and its relation to severity of diseases. After serial 2-fold dilution of urine, the highest dilution for positive results was determined, and this was designated as maximum dilution factor (MDF). MDFs varied from 1 to 4096 in 29 patients examined (mean MDF, 317.8). Importantly, severe cases of S. pneumoniae pneumonia were higher values of MDFs (mean MDF: 760.5) than those of non-severe cases (mean MDF: 5.4). The patients with high MDFs (> or = 64) demonstrated higher values of LDH, CRP and lower values of WBC and PaO2 compared to those of low MDFs group (< or = 32). There was no clear correlation between CRP values and antigen titers, and conversely the majority of severe cases showed relatively weak CRP responses, despite high levels of bacterial antigen. Kinetic analysis of urinary and serum antigen titers in 4 cases of S. pneumoniae pneumonia exhibited consistently higher values of antigen titers in urine than those in serum. The half lives of urinary and serum antigen titers were calculated to be 1.0-3.4 and 1.1-2.3 weeks, respectively. These data suggest that quantitative analysis of urinary antigen may be a useful indicator for severity of disease and course of S. pneumoniae pneumonia. Our results demonstrate an application for S. pneumoniae antigen titer determination in urine and serum, which may be crucial not only for diagnostic measures, but also may provide a better understanding of the pathogenesis of S. pneumoniae infection.

Detection of Streptococcus pneumoniae Antigen in Bronchoalveolar Lavage Fluid Samples by a Rapid Immunochromatographic Membrane Assay

We conducted a retrospective study to evaluate an immunochromatographic membrane test (ICT), applied to bronchoalveolar lavage (BAL) fluid samples obtained in patients with suspected pneumonia, for the detection of Streptococcus pneumoniae antigen. The NOW Streptococcus pneumoniae test was assessed on 96 BAL fluid samples. Sensitivity was tested in 20 samples obtained from patients diagnosed as having pneumococcal pneumonia (growth of S. pneumoniae in blood cultures and/or in BAL fluid samples of > or =10(4) CFU/ml). Specificity was tested in BAL fluid samples of nonpneumococcal etiology (n = 41) and in samples with no respiratory pathogen and a total bacterial count of <10(4) CFU/ml (n = 35). Using the ICT, pneumococcal antigen was detected in 29 (30.2%) BAL fluid samples, with a sensitivity of 95.0% (95% confidence interval [CI], 90.6% to 99.4%) and a specificity of 86.8% (95% CI, 80.1% to 93.8%). The ICT was easy to perform and revealed unequivocal and reproducible results. No interference was observed with high cell counts, red blood cells, or elevated protein levels. Four out of 10 false-positive readings occurred in samples with S. pneumoniae counts below the 10(4) CFU/ml threshold limit of pneumonia. In BAL fluid samples obtained after pneumococcal bacteremia, positive test results were found for up to 35 days after bacteremia. The ICT test applied to BAL fluid specimens is reproducible and accurate in the diagnosis of pneumococcal antigen. Further studies are required to establish the impact of the ICT on patient care.

A 3-year prospective study of a urinary antigen-detection test for Streptococcus pneumoniae in community-acquired pneumonia: utility and clinical impact on the reported etiology

To evaluate the efficacy of a rapid immunochromatographic membrane test (ICT) for the detection of Streptococcus pneumoniae urinary antigen for diagnosing S. pneumoniae pneumonia, ICT was performed with urine samples using the Binax NOW Streptococcus pneumoniae kit at the time of admission. The results were compared with those from conventional microbiological studies. Three hundred and forty-nine adult patients with CAP who were admitted to the hospital were studied prospectively between February 2001 and January 2004. The ICT test was positive in 115 (33.0%) of 349 patients enrolled into the study and in 63 (75.9%) of 83 patients with pneumococcal pneumonia confirmed by conventional methods. The test revealed a sensitivity of 75.9% and a specificity of 94.0% with conventional microbiological criteria used as the reference standard. The positive predictive value was 91.3%, and the negative predictive value was 82.6%. The clinical features of 53 patients in whom ICT was positive and no pathogen was identified showed no significant difference from those of 83 patients who had pneumococcal pneumonia identified by conventional methods. The diagnostic yield of pneumococcal pneumonia was increased up to 38.9% using ICT combined with conventional methods. The Binax NOW ICT to detect S. pneumoniae urinary antigen is therefore a rapid and useful method for diagnosing pneumococcal pneumonia. Induction of ICT will prove the predominance of S. pneumoniae in the etiology of CAP.

Rapid urinary antigen test for diagnosis of pneumococcal community-acquired pneumonia in adults.

Streptococcus pneumoniae is suspected to cause an important proportion of community-acquired pneumonia (CAP) whose aetiology cannot be detected with conventional tests. In this study, the authors evaluated the diagnostic yield of a new immunochromatographic membrane test (ICT) for the detection of the S. pneumoniae antigen in the urine of patients admitted with diagnosed CAP. ICT was performed in unconcentrated and concentrated urine from all the patients. ICT was repeated 1 month after discharge in a group initially testing positive. The authors also studied the ICT in clinically stable human immunodeficiency virus type 1 (HIV1)-infected patients. S. pneumoniae antigen was detected in all of the 68 (100%) patients tested with definitive pneumococcal pneumonia. In five of these cases ICT was only positive when it had been performed on the patients. The S. pneumoniae antigen was also detected in 36 (69.2%) of 52 patients with probable pneumococcal pneumonia and in 50 of 277 (18%) patients without pneumococcal pneumonia. ICT remained positive in 16 (69.5%) of 23 patients, 1 month after hospital discharge. Nasopharyngeal colonisation with S. pneumoniae was detected in 8 (12%) of 68 clinically stable HIV1 infected patients, but none tested ICT positive. The Binax NOW it immunochromatographic membrane test is a rapid, sensitive and specific test for detecting pneumococcal community-acquired pneumonia in adults. The test may remain positive for several weeks after pneumococcal pneumonia.

Use of the “SMITEST” PSA card to identify the presence of prostate-specific antigen in semen and male urine

To determine whether the prostate-specific antigen (PSA) could be identified in semen using the “SMITEST” PSA immunochromatographic membrane test card, we examined semen and other body fluids, including urine. Although PSA activity was detected in semen with high sensitivity using the “SMITEST” PSA card, it was also detected in adult male urine. However, the lower detectable limit in the urine was 1000-fold lower than that in semen. The concentration of PSA in adult male urine was found to be 800ng/ml using the card. PSA activity usually can be detected in urine of individuals over 14 years old and it has been detected in urine from children as young as 11 years old. Therefore, the appearance of PSA in urine may occur anytime between the age of 12 and 14 years. To determine the stability of PSA activity in urine, dried samples of urine on filter paper were kept at room temperature for up to 3 years. Although the immunoreactive line showing PSA activity became weak after storage, it was still detectable, but faint, after 3 years. In addition, PSA activity was not detected in male serum or saliva and in the urine from human females, male cats or male dogs using the PSA card. We conclude that the PSA card is useful for identification of PSA in both semen and adult male urine.

Detection of Streptococcus pneumoniae Antigen by a Rapid Immunochromatographic Assay in Urine Samples

Evaluation of a newly available rapid (15 min) immunochromatographic membrane test (ICT) to detect Streptococcus pneumoniae in urine samples, in order to assess its utility in the diagnosis of bacteremic and nonbacteremic pneumococcal pneumonia. Retrospective study. We studied urine samples from 51 patients with bacteremic and nonbacteremic pneumonia due to S pneumoniae diagnosed by blood culture and pneumococcal polysaccharide capsular antigen detection by counterimmunoelectrophoresis in urine samples, 16 patients with probable pneumococcal pneumonia, 71 patients with nonpneumococcal pneumonia, and 16 patients with pneumonia but no pathogen identified. Urine samples were collected and frozen at - 20 degrees C until used. The ICT test was performed following the instructions of the manufacturer. S. pneumoniae antigen was detected in 41 of 51 patients with pneumococcal pneumonia (80.4%); results were positive in 23 of 28 bacteremic cases (82.1%) and in 18 of 23 nonbacteremic cases (78.3%). From patients with a diagnosis of presumptive pneumococcal pneumonia, antigen was detected in seven urine samples (43.7%) and also in one case of the 16 patients with pneumonia but no pathogen identified. The specificity of the ICT test was 97.2%. The ICT assay is a valuable tool for the diagnosis of pneumococcal pneumonia, especially for the nonbacteremic cases.