Self-Collected Samples to Detect SARS-CoV-2: Direct Comparison of Saliva, Tongue Swab, Nasal Swab, Chewed Cotton Pads and Gargle Lavage.

Testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by RT-PCR is a vital public health tool in the pandemic. Self-collected samples are increasingly used as an alternative to nasopharyngeal swabs. Several studies suggested that they are sufficiently sensitive to be a useful alternative. However, there are limited data directly comparing several different types of self-collected materials to determine which material is preferable. A total of 102 predominantly symptomatic adults with a confirmed SARS-CoV-2 infection self-collected native saliva, a tongue swab, a mid-turbinate nasal swab, saliva obtained by chewing a cotton pad and gargle lavage, within 48 h of initial diagnosis. Sample collection was unsupervised. Both native saliva and gargling with tap water had high diagnostic sensitivity of 92.8% and 89.1%, respectively. Nasal swabs had a sensitivity of 85.1%, which was not significantly inferior to saliva (p = 0.092), but 16.6% of participants reported they had difficult in self-collection of this sample. A tongue swab and saliva obtained by chewing a cotton pad had a significantly lower sensitivity of 74.2% and 70.2%, respectively. Diagnostic sensitivity was not related to the presence of clinical symptoms or to age. When comparing self-collected specimens from different material, saliva, gargle lavage or mid-turbinate nasal swabs may be considered for most symptomatic patients. However, complementary experiments are required to verify that differences in performance observed among the five sampling modes were not attributed to collection impairment.

Non-surgical periodontal therapy with adjunctive topical doxycycline: a double-masked, randomized, controlled multicenter study. II. Microbiological results.

BACKGROUND: Topical application of active substances offers an additional option in periodontal therapy. The aim of this study was to examine the influence of the administration of a novel, biodegradable 14% doxycycline gel on microbiological findings, in connection with scaling and root planing. METHODS: One hundred ten patients in three centers (Frankfurt and Heidelberg, Germany; Nijmegen, The Netherlands) with moderate to advanced periodontitis were evaluated in this randomized, double-masked, split-mouth clinical trial. In each patient, three test teeth were randomly assigned to one of three treatment modalities: 1) scaling and root planing (SRP) alone; 2) SRP with subgingival placebo gel (VEH); or 3) SRP and 14% doxycycline gel (DOX). Subgingival plaque samples were analyzed at baseline and 3 and 6 months after therapy for Actinobacillus actinomycetemcomitans (A.a.), Tannerella forsythensis (T.f.), Porphyromonas gingivalis (P.g.), and Treponema denticola (T.d.) using a RNA probe. Samples from 10 patients were tested for resistance against doxycycline, amoxicillin/clavulanic acid, cefoxitin, clindamycin, and metronidazole using agar diffusion testing. RESULTS: The largest decrease in pathogens was found after 3 months, with the most pronounced differences between DOX and SRP (P <0.05). At 6 months, pathogens were still reduced markedly in all groups. Treatment results were consolidated for VEH and DOX, with a slight deterioration for SRP (DOX versus SRP: P <0.001). Resistance was observed to amoxycillin/clavulanic acid, cefoxitin, clindamycin, and metronidazole (four isolates) but not to doxycycline. CONCLUSION: The addition of subgingival instillation of a 14% doxycycline gel resulted in pronounced reduction of periodontal pathogens after 3 months and stabilizing results up to 6 months after therapy. Resistance to doxycycline was not induced.

Continued vigilance - development of an online evaluation tool for assessing preparedness of medical facilities for biological events.

OBJECTIVE: Effective response to biological events necessitates ongoing evaluation of preparedness. This study was a bilateral German-Israeli collaboration aimed at developing an evaluation tool for assessing preparedness of medical facilities for biological events. METHODS: Measurable parameters were identified through a literature review for inclusion in the evaluation tool and disseminated to 228 content experts in two modified Delphi cycles. Focus groups were conducted to identify psychosocial needs of the medical teams. Table-top and functional exercises were implemented to review applicability of the tool. RESULTS: One hundred seventeen experts from Germany and Israel participated in the modified Delphi. Out of 188 parameters that were identified, 183 achieved a consensus of >75% of the content experts. Following comments recommended in the Delphi cycles, and feedback from focus groups and hospital exercises, the final tool consisted of 172 parameters. Median level of importance of each parameter was calculated based on ranking recommended in the Delphi process. Computerized web-based software was developed to calculate scores of preparedness for biological events. CONCLUSION: Ongoing evaluation means, such as the tool developed in the study, can facilitate the need for a valid and reliable mechanism that may be widely adopted and implemented as quality assurance measures. The tool is based on measurable parameters and indicators that can effectively present strengths and weaknesses in managing a response to a public health threat, and accordingly, steps can be implemented to improve readiness. Adoption of such a tool is an important component of assuring public health and effective emergency management.

Biological cost of rifampin resistance from the perspective of Staphylococcus aureus.

Resistance determinants that interfere with normal physiological processes in the bacterial cell usually cause a reduction in biological fitness. Fitness assays revealed that 17 of 18 in vitro-selected chromosomal mutations within the rpoB gene accounting for rifampin resistance in Staphylococcus aureus were associated with a reduction in the level of fitness. There was no obvious correlation between the level of resistance to rifampin and the level of fitness loss caused by rpoB mutations. Among 23 clinical rifampin-resistant S. aureus isolates from six countries, only seven different rpoB genotypes could be identified, whereby the mutation 481His-->Asn was present in 21 (91%) of these 23 isolates. The mutation 481His-->Asn, in turn, which confers low-level rifampin resistance on its own, was not shown to be associated with a cost of resistance in vitro. The restriction to distinct mutations that confer rifampin resistance in vivo, as demonstrated here, appears to be determined by the Darwinian fitness of the organisms.

Cross-talk between nitric oxide and superoxide determines ceramide formation and apoptosis in glomerular cells.

BACKGROUND: The modulation of cell signaling by nitric oxide (NO) and superoxide (O(-)(2)) is associated with apoptotic cell death in inflammatory kidney diseases. Recently, we have shown that NO induces ceramide production in glomerular mesangial and endothelial cells and the ratio of NO and O(-)(2) determines whether cells live or die. METHODS: Glomerular endothelial and mesangial cells were labeled with [(14)C]serine, the precursor of all sphingolipids, then stimulated with reactive oxygen species- or reactive nitrogen species-generating substances and subjected to lipid extraction. Radioactive lipids were separated and analyzed by thin-layer chromatography. DNA fragmentation, as a characteristic feature of apoptosis, was measured by a nucleosome/DNA-ELISA, which quantitatively recorded the histone-associated DNA fragments. RESULTS: Exposure of glomerular endothelial and mesangial cells to either NO donors or superoxide-generating substances led to a delayed and sustained ceramide formation that paralleled the induction of apoptosis in both cell types. Coincubation of endothelial cells with NO and superoxide, which led to the generation of peroxynitrite, caused a synergistic enhancement of ceramide generation and apoptosis when compared to either stimulus alone. By contrast, in glomerular mesangial cells costimulation with superoxide neutralized not only NO-induced apoptosis but also NO-induced ceramide formation, although O(-)(2) alone triggered ceramide formation in mesangial cells and caused cell death. Moreover, SIN-1, a substance that simultaneously releases NO and O(-)(2) and thereby generates peroxynitrite, also stimulated a delayed ceramide formation in endothelial cells but not in mesangial cells. Furthermore, exposure of endothelial cells to glucose oxidase, which generates hydrogen peroxide, or to exogenous hydrogen peroxide, also showed a dose-dependent increase in ceramide formation and apoptosis, although to a lesser extent than did superoxide. CONCLUSIONS: These data suggest that ceramide represents an important mediator of reactive oxygen and nitrogen species-triggered cell responses, like apoptosis. There seem to be cell type-specific protective mechanisms that critically depend on a fine-tuned redox balance between reactive nitrogen and oxygen species to determine whether a cell undergoes apoptosis or survives when exposed to oxidative and/or nitrosative stress conditions.