The performance of the new ePlex Respiratory Pathogen (RP) panel (GenMark Diagnostics) for the simultaneous detection of 19 viruses (influenza A virus; influenza A H1 virus; influenza A 2009 H1 virus; influenza A H3 virus; influenza B virus; adenovirus; coronaviruses [HKU1, OC43, NL63, and 229E]; human rhinovirus/enterovirus; human metapneumovirus; parainfluenza viruses 1, 2, 3, and 4; and respiratory syncytial virus [RSV] [RSV subtype A and RSV subtype B]) and 2 bacteria (Mycoplasma pneumoniae and Chlamydia pneumoniae) was evaluated. Prospectively and retrospectively collected nasopharyngeal swab (NPS) specimens (n = 2,908) were evaluated by using the ePlex RP panel, with the bioMérieux/BioFire FilmArray Respiratory Panel (BioFire RP) as the comparator method. Discordance analysis was performed by using target-specific PCRs and bidirectional sequencing. The reproducibility of the assay was evaluated by using reproducibility panels comprised of 6 pathogens. The overall agreement between the ePlex RP and BioFire RP results was >95% for all targets. Positive percent agreement with the BioFire RP result for viruses ranged from 85.1% (95% confidence interval [CI], 80.2% to 88.9%) to 95.1% (95% CI, 89.0% to 97.9%), while negative percent agreement values ranged from 99.5% (95% CI, 99.1% to 99.7%) to 99.8% (95% CI, 99.5% to 99.9%). Additional testing of discordant targets (12%; 349/2,908) confirmed the results of ePlex RP for 38% (131/349) of samples tested. Reproducibility was 100% for all targets tested, with the exception of adenovirus, for which reproducibilities were 91.6% at low virus concentrations and 100% at moderate virus concentrations. The ePlex RP panel offers a new, rapid, and sensitive “sample-to-answer” multiplex panel for the detection of the most common viral and bacterial respiratory pathogens.

Clostridium difficile, the primary cause of nosocomial diarrhea in the United States and many other industrialized countries, is recognized as a major health concern because of its ability to cause severe intestinal disease leading to complications such as relapses and infections due to vancomycin-resistant enterococci. The disease results from two toxins, toxins A and B, produced by this pathogen. In this study, we evaluated the TOX A/B TEST, a new 1-h enzyme immunoassay (EIA) that detects toxins A and B. We compared the test with the tissue culture assay, which is recognized as the “gold standard” forC. difficile testing. Evaluations were performed in-house at TechLab, Inc. (Blacksburg, Va.) and off-site at four clinical laboratories. Of 1,152 specimens tested, 165 were positive by the TOX A/B TEST and tissue culture and 973 were negative by both tests. The sensitivity and specificity were 92.2 and 100%, respectively. The positive and negative predictive values were 100 and 98.6%, respectively, and the correlation of the TOX A/B TEST with tissue culture was 98.8%. When discrepant samples were resolved by culture, the sensitivity and specificity were 93.2 and 98.9%, respectively. The positive and negative predictive values were 100 and 98.8%, respectively, with a correlation of 99.0%. There were no specimens that were positive by the TOX A/B TEST and negative by tissue culture. Fourteen specimens were negative by the TOX A/B TEST but positive by tissue culture. Of these, two were negative by toxigenic culture, five were positive by toxigenic culture, and seven were not available for further testing. There were no indeterminate results, since the test does not have an indeterminant zone. In a separate study, 102 specimens that were positive by tissue culture and the TOX A/B TEST were examined in toxin A-specific EIAs. Two specimens that presumptively contained toxin A-negative, toxin B-positive (toxA−/toxB+) isolates were identified. One specimen was from a patient with a clinical history consistent with C. difficile infection. Isolates obtained from these specimens by selective culture on solid media and in broth tested toxA−/toxB+ when grown in brain heart infusion dialysis flasks, which stimulate in vitro production of both toxins. Our findings show that the TOX A/B TEST is suitable as a diagnostic aid for C. difficile disease because it correlates well with tissue culture and detects isolates that may be missed with toxin A-specific EIAs.

BackgroundProbiotics have beneficial effects in rodent models of Clostridium difficile (C. diffiicle)-induced colitis. The spore forming probiotic strain Bacillus Coagulans GBI-30, 6086 (BC30) has demonstrated anti-inflammatory and immune-modulating effects in vitro. Our goal was to determine if BC30 improved C. difficile-induced colitis in mice. Starting on study day 0, female C57BL/6 mice were dosed by oro-gastric gavage for 15 days with vehicle (saline) or BC30 (2 × 109 CFU per day). Mice in the C. difficile groups received an antibiotic mixture (study days 5 to 8 in the drinking water), and clindamycin (10 mg/kg, i.p., on study day 10). The C. difficile strain VPI 10463 was given by gavage at 104 CFU to induce colitis on day 11. On day 16, stools and colons were collected for further analyses.ResultsAll mice treated with BC30 survived on study day 13, while two mice treated with vehicle did not survive. On day 12, a significant difference (p = 0.0002) in the percentage of mice with normal stools (66.7%) was found in the BC30/C. difficile group, as compared to the vehicle/C. diffcile group (13.0%). On study day 16, 23.8% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0187). On this day, the stool consistency score for the BC30/C. difficile group (1.1 ± 0.2) was significantly lower (p < 0.05) than for the vehicle/C. difficile cohort (1.9 ± 0.2). BC30 modestly attenuated the colonic pathology (crypt damage, edema, leukocyte influx) that was present following C. difficile infection. Colonic MIP-2 chemokine contents (pg/2 cm colon) were: 10.2 ± 0.5 (vehicle/no C. difficile), 24.6 ± 9.5 (vehicle/C. difficile) and 16.3 ± 4.3 (BC30/C. difficle).ConclusionThe probiotic BC30 improved some parameters of C. difficile-induced colitis in mice. BC30 prolonged the survival of C. diffiicle infected mice. Particularly, this probiotic improved the stool consistency of mice, in this infectious colitis model.

BackgroundRecently, we found that the probiotic strain Bacillus coagulans GBI-30, 6086 (GanedenBC30) improved indices of Clostridium difficile (C. difficile)-induced colitis in mice (Fitzpatrick et al., Gut Pathogens, 2011). Our goal was to determine if BC30 could also prevent the recurrence of C. difficile-induced colitis in mice, following initial treatment with vancomycin. During study days 0 through 5, mice were treated with antibiotics. On day 6, the C. difficile strain VPI 10463 was given by oro-gastric gavage at ≈ 5x104 CFU to induce colitis. Mice were treated on study days 6 to 10 with vancomycin (50 mg/kg) (vanco) or vehicle (saline) by gavage. On days 10 to16, mice were dosed by gavage with saline vehicle or BC30 (2 x 109 CFU per day). Mice were monitored for mortality, weight loss and diarrhea. On study days 14, 16 and 17, stools and colons were collected for analyzing other parameters of colitis.ResultsThe mean stool consistency score in Vehicle/C.difficile/Vanco mice increased from 0.4 (day 10) to a range of 1.1 to 1.4 (days 14 to 17), indicating the recurrence of colitis. On days 13 through 17, the stool consistency scores for the vancomycin/BC30 mice were significantly lower (p< 0.05) than for the vancomycin/vehicle cohort of animals. On day 17, 88.9% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0004). Colonic myeloperoxidase (Units/2 cm colon) was significantly (p < 0.05) reduced from 4.3 ± 0.7 (Vehicle/C.difficile/Vanco) to 2.6 ± 0.2 (BC30/C. Difficle/Vanco). The colonic histology score and Keratinocyte derived-chemokine level in the colon were also lower in BC30 treated mice.SummaryIn BC30-treated mice, there was evidence of better stool consistency, as well as improved biochemical and histological indices of colitis, following initial treatment of animals with vancomycin.ConclusionBC30 limited the recurrence of CD-induced colitis following vancomycin withdrawal in mice.