Clostridioides difficile in Outpatients: Application of a Diagnostic Algorithm Recommended by the European Society of Clinical Microbiology and Infectious Diseases.

This study aimed at evaluating in outpatients an algorithm for the laboratory diagnosis of Clostridioides (Clostridium) difficile infection (CDI), i.e., enzyme immunoassays (EIAs) detecting bacterial glutamate dehydrogenase (GDH) and toxin A/B, followed by polymerase chain reaction (PCR) analyses of samples with discordant EIA results. In total, 9802 examinations of stool samples by GDH and toxin EIAs performed in 7263 outpatients and 488 inpatients were analyzed retrospectively. Samples with discordant EIA results had been tested by a commercially available PCR assay detecting genes of the C. difficile-specific triose phosphate isomerase (tpi) and toxin B (tcdB). Concordant EIA results (686 C. difficile-positive, 8121 negative) were observed for 8807 (89.8%; 95% CI, 89.2-90.4%) samples. Of 958 samples with discordant EIA results, 895 were analyzed using PCR and 580 of 854 GDH-positive/borderline, toxin-negative samples (67.9%; 95% CI, 64.7-71.0%) were positive for tpi and tcdB, while 274 samples (32.1%; 95% CI, 29.0-35.3%) were tcdB-negative. In contrast, 35 of 41 GDH-negative, toxin-positive/borderline samples (85.4%; 95% CI, 71.2-93.5%) were tcdB-negative. Still, 6 samples (14.6%; 95% CI, 6.5-28.8%) yielded positive PCR results for both genes. In conclusion, around 90% of the samples were analyzed appropriately by only applying EIAs. Approximately one third of the PCR-analyzed samples were tcdB-negative; thus, patients most likely did not require CDI treatment.

Accurate Detection of Helicobacter pylori Antigen in Human Stool Specimens by Two Novel Immunoassays.

Stool antigen tests are recommended for the diagnosis of Helicobacter pylori infection. Here, we compared two novel assays, i.e., one enzyme immunoassay (EIA) and one immunochromatography assay (ICA), with a chemiluminescence immunoassay (CLIA) that had previously been compared with rapid urease test, histology, and urea breath test. Two hundred sixty-six frozen stool samples with defined CLIA results (42 positives, 219 negatives, and 5 samples with borderline results) collected between January and May 2018 were thawed and immediately tested by EIA, ICA, and CLIA. In 248 samples with repeatedly positive/negative CLIA results, EIA and ICA were positive for 40 and 37 of 41 CLIA-positive samples and yielded negative results for 206 and 201 of 207 CLIA-negative samples, respectively. There was a high positive percent agreement (EIA, 97.6%; 95% confidence interval (95% CI), 86.3-100%; ICA, 90.2%; 95% CI, 76.9-96.7%), as well as a negative percent agreement between the assays (EIA, 99.5%; 95% CI, 97.0-100%; ICA, 97.1%; 95% CI, 93.7-98.8%). This was further supported by kappa values indicating very good agreement (CLIA vs. EIA, 0.971; CLIA vs. ICA, 0.857). In conclusion, both EIA and ICA comprise valuable assays for the detection of H. pylori antigen in stool samples.

Detection of Enterobius vermicularis in greater Berlin, 2007-2017: seasonality and increased frequency of detection.

The pinworm (Enterobius vermicularis) causes mostly mild infections characterised by nocturnal anal pruritus, mainly in children. Still, the infection is stigmatising and sleep disturbances may lead to lack of concentration. For Germany, no epidemiological data are available. Laboratory data of all patients for whom detection of E. vermicularis by cellulose tape test had been requested between 2007 and November 2017 were analysed retrospectively. E. vermicularis was detected in 971/5578 (17.4%) samples collected from 3991 patients. The detection rate increased significantly within the period of investigation. It was higher in male than in female patients (20.0 vs. 15.4%). Children 4 to 10 years old and, if also examined, their relatives were most frequently affected. Control investigations at an interval of at least 1 month, which could indicate insufficient therapy or re-infection, were performed in 90/714 patients (12.6%). While parasite detection in children < 6 years was evenly distributed throughout the year, in older patients, it peaked between October and December. In conclusion, in the area of investigation, the frequency of E. vermicularis is higher in males than in females and is subject to a hitherto undescribed seasonality. The causes of the increased frequency of parasite detection warrant further investigations.

Characterization of a new marine nitrite oxidizing bacterium, Nitrospina watsonii sp. nov., a member of the newly proposed phylum "Nitrospinae".

Nitrite oxidizing bacteria are an integral part of the nitrogen cycle in marine waters, but the knowledge about their diversity is limited. Recently, a high abundance of Nitrospina-like 16S rRNA gene sequences has been detected in oceanic habitats with low oxygen content by molecular methods. Here, we describe a new strain of Nitrospina, which was sampled in 100m depth from the Black Sea. It coexisted with a not-yet cultivated chemoorganotrophic gammaproteobacterium and could be purified by classical isolation methods including Percoll density gradient centrifugation. The new Nitrospina-like bacterium grew lithoautotrophically at 28°C in diluted seawater supplemented with inorganic salts and nitrite. Gram-negative rods were characterized morphologically, physiologically and partly biochemically. The 16S rRNA gene of the new strain of Nitrospina is 97.9% similar to the described species N. gracilis and DNA/DNA hybridization experiments revealed a relatedness of 30.0%. The data from both Nitrospina species and environmental clones were used for an extensive 16S rRNA based phylogenetic study applying high quality filtering. Treeing analyses confirm the newly defined phylum status for "Nitrospinae" [18]. The results of phylogenetic and genotypic analyses support the proposal of a novel species Nitrospina watsonii sp. nov. (type strain 347(T), LMG 27401(T), NCIMB 14887(T)).