[Fusarium Keratitis-an upcoming threat in Germany?] / Keratitis durch Fusarien ­ eine zunehmende Bedrohung in Deutschland?

BACKGROUND: Fungal keratitis due to Fusarium species is known to be typical of developing countries; however, with the increasing use of contact lenses a rise of Fusarium keratitis has been observed in Germany. METHODS: In a monocentric retrospective study, we analyzed all patients who presented to our university eye hospital with infectious keratitis between January 2011 and December 2021 and had a proof of Fusarium species in either microscopy, culture or PCR. RESULTS: We could identify 13 patients with a proof of Fusarium species. A significant increase of cases in 2021 was observed. In 76.9% of our cases the patients were female and in 76.9% the patients had a history of prior contact lens use. In only 4 cases the initial corneal sample gave a positive result for Fusarium. On average the suspicion of fungal keratitis arose 13.1 days after onset of symptoms, correct diagnosis was achieved after 14.6 days. All isolated specimens showed resistance against at least one of the common fungicides. In 70% of our cases treatment with penetrating keratoplasty was necessary. The patients showed a 57.1% recurrence rate after penetrating keratoplasty. In 80% of our cases best documented visual acuity after Fusarium keratitis was ≤ 0.4. CONCLUSION: Due to difficult detection and a high resistance rate to common antifungals, Fusarium keratitis is prone to delayed diagnosis and limited treatment outcomes. Whenever risk factors are present and infectious keratitis does not respond to antibiotics, antimycotic treatment must be initiated. Early keratoplasty may be necessary.

The potential of SARS-CoV-2 antigen-detection tests in the screening of asymptomatic persons.

OBJECTIVES: The aim was to assess the performance of antigen-based rapid diagnostic tests (Ag-RDTs) for SARS CoV-2 when implemented for large-scale universal screening of asymptomatic individuals. METHODS: This study was a pragmatic implementation study for universal Ag-RDT-based screening at a tertiary care hospital in Germany where patients presenting for elective procedures and selected personnel without symptoms suggestive of SARS-CoV-2 were screened with an Ag-RDT since October 2020. Test performance was calculated on an individual patient level. RESULTS: In total, 49 542 RDTs were performed in 27 421 asymptomatic individuals over a duration of 5 and a half months. Out of 222 positive results, 196 underwent in-house confirmatory testing with PCR, out of which 170 were confirmed positive, indicating a positive predictive value of 86.7% (95% CI 81.2-91.1%). Negative Ag-RDTs were not routinely tested with PCR, but a total of 94 cases of false negative Ag-RDTs were detected due to PCR tests being performed within the following 5 days with a median cycle threshold value of 33 (IQR 29-35). DISCUSSION: This study provides evidence that Ag-RDTs can have a high diagnostic yield for transmission relevant infections with limited false positives when utilized at the point of care on asymptomatic patients and thus can be a suitable public health test for universal screening.

Workflow optimization for syndromic diarrhea diagnosis using the molecular Seegene Allplex™ GI-Bacteria(I) assay.

Syndromic panel-based molecular testing has been suggested to improve and accelerate microbiological diagnosis. We aimed to analyze workflow improvements when using the multiplex Seegene Allplex™ GI-Bacteria(I) assay as a first-line assay for bacterial diarrhea. Technical assay evaluation was done using spiked stool samples and stored patient samples. After implementation of the assay in the routine clinical workflow, an analysis of 5032 clinical samples analyzed by the Seegene assay and 4173 control samples examined by culture in a similar time period 1 year earlier was performed. Sensitivity of the assay was shown to be between 0.4 and 95.9 genome equivalents/PCR. For 159 positive patient samples with a composite reference of culture and/or a molecular assay, the sensitivity of the assay was 100% for Campylobacter, 92% for Salmonella, 89% for Aeromonas, and 83% for Shigella. Sensitivity for C. difficile toxin B detection was 93.9%. The comparison of clinical samples obtained in two 8-month periods showed increased detection rates for Aeromonas (2.90%vs. 0.34%), Campylobacter spp. (2.25% vs. 1.34%), Shigella spp. (0.42% vs. 0.05%) whereas detection of Salmonella was slightly decreased (0.46% vs. 0.67%) when using the Seegene assay. An analysis of the time-to-result showed that the median dropped from 52.7 to 26.4 h when using the molecular panel testing. The Seegene Allplex™ GI-Bacteria(I) assay allows accelerated, reliable detection of major gastrointestinal bacteria roughly within 1 day. Workload is reduced, specifically in a low-prevalence setting.

Detection of MRSA in nasal swabs-marked reduction of time to report for negative reports by substituting classical manual workflow with total lab automation.

In 2016, the workflow for MRSA detection in nasal swabs was changed from a classic-manual workflow to an automated workflow using total lab automation (TLA; BD Kiestra). This change entailed a reduction of the incubation time from 2 days to 20 h and reading of plates on weekdays and weekends instead of weekdays only. The workflow alteration did not include the introduction of 24/7. We wanted to follow up on the consequences for the times to report (TTR). We compared the TTR of all nasal swabs, which were sent for MRSA detection from June until August in 2015 (workflow-classic-manual) and in 2016 (workflow-automated). We calculated median TTR and interquartile ranges for the three possible reporting outcomes (negative, MRSA-known, MRSA-new) per day and workflow. A multivariable linear regression modeled the exposure variables workflow, day, and reporting outcome on TTR including interaction variables. The quantity and reasons for a TTR longer than 3 days were analyzed. During both 3-month periods, a total of 16,111 reports were issued (2015:7620; 2016:8491). The median TTR for negative reports was 48:28 (hh:mm) in 2015 and 23:58 in 2016. In the linear regression, all exposure variables had a strong and highly significant (p < 0.001) influence on the TTR. The number of reports with a TTR longer than 3 days shrank from 2418 (2015) to 60 (2016). The workflow alteration halved the median TTR for negative reports and the number of reports with a TTR longer than 3 days was reduced by 97.5%.

Significant increase in cultivation of Gardnerella vaginalis, Alloscardovia omnicolens, Actinotignum schaalii, and Actinomyces spp. in urine samples with total laboratory automation.

While total laboratory automation (TLA) is well established in laboratory medicine, only a few microbiological laboratories are using TLA systems. Especially in terms of speed and accuracy, working with TLA is expected to be superior to conventional microbiology. We compared in total 35,564 microbiological urine cultures with and without incubation and processing with BD Kiestra TLA for a 6-month period each retrospectively. Sixteen thousand three hundred thirty-eight urine samples were analyzed in the pre-TLA period and 19,226 with TLA. Sixty-two percent (n = 10,101/16338) of the cultures processed without TLA and 68% (n = 13,102/19226) of the cultures processed with TLA showed growth. There were significantly more samples with two or more species per sample and with low numbers of colony forming units (CFU) after incubation with TLA. Regarding the type of bacteria, there were comparable amounts of Enterobacteriaceae in the samples, slightly less non-fermenting Gram-negative bacteria, but significantly more Gram-positive cocci, and Gram-positive rods. Especially Alloscardivia omnicolens, Gardnerella vaginalis, Actinomyces spp., and Actinotignum schaalii were significantly more abundant in the samples incubated and processed with TLA. The time to report was significantly lower in the TLA processed samples by 1.5 h. We provide the first report in Europe of a large number of urine samples processed with TLA. TLA showed enhanced growth of non-classical and rarely cultured bacteria from urine samples. Our findings suggest that previously underestimated bacteria may be relevant pathogens for urinary tract infections. Further studies are needed to confirm our findings.

The novel suramin analogue NF864 selectively blocks P2X1 receptors in human platelets with potency in the low nanomolar range.

The role of ATP-stimulated P2X1 receptors in human platelets is still unclear. They may act alone or in synergy with other pathways, such as P2Y1 or P2Y12 receptors, to accelerate and enhance calcium mobilisation, shape change and aggregation. To date very few pharmacological means of selectively inhibiting platelet P2X1 receptors have been described, although recent work has shown that suramin is a useful lead compound for the development of high-affinity P2X1 antagonists. We therefore investigated the effects of a series of bivalent and tetravalent suramin analogues on alphabeta meATP (P2X1 receptors)-induced or ADP (P2Y1 receptors)-induced intracellular calcium increases and shape change, as well as on ADP-induced aggregation (P2Y1 & P2Y12 receptors) in human platelets. Changes in intracellular calcium were measured using standard fluorescence techniques, while shape change and aggregation were determined by turbidimetry. The novel tetravalent compound NF864 (8,8',8'',8'''-(carbonylbis(imino-5,1,3-benzenetriyl-bis(carbonylimino)))tetrakis-naphthalene-1,3,5-trisulfonic acid-dodecasodium salt) proved to be the most potent platelet P2X1 antagonist reported to date, blocking alphabeta meATP-induced Ca2+ increases and shape change in a concentration-dependent manner, with a pA2 of 8.17 and 8.49, respectively. The ability to inhibit the platelet P2X1 receptor displayed the following order : NF864 > NF449 > or = NF110 > NF023 = MK-HU1 = suramin. A different antagonistic profile was observed for ADP-induced Ca2+ increases, shape change and aggregation; however, overall four compounds showed sufficient ability to selectively inhibit P2X1 responses, with the order NF110 > NF449 > or = NF864 > or = MK-HU1. Therefore, these compounds should prove useful tools for investigating the functional significance of platelet P2X1 receptors in thrombosis and haemostasis, NF864 being the most promising compound.