ABSTRACT
"Ancestral" Mycobacterium tuberculosis complex (MTBC) strains of Lineage 1 (L1, East African Indian) are a prominent tuberculosis (TB) cause in countries around the Indian Ocean. However, the pathobiology of L1 strains is insufficiently characterized. Here, we used whole genome sequencing (WGS) of 312 L1 strains from 43 countries to perform a characterization of the global L1 population structure and correlate this to the analysis of the synthesis of phenolic glycolipids (PGL) - known MTBC polyketide-derived virulence factors. Our results reveal the presence of eight major L1 sub-lineages, whose members have specific mutation signatures in PGL biosynthesis genes, e.g., pks15/1 or glycosyltransferases Rv2962c and/or Rv2958c. Sub-lineage specific PGL production was studied by NMR-based lipid profiling and strains with a completely abolished phenolphthiocerol dimycoserosate biosynthesis showed in average a more prominent growth in human macrophages. In conclusion, our results show a diverse population structure of L1 strains that is associated with the presence of specific PGL types. This includes the occurrence of mycoside B in one sub-lineage, representing the first description of a PGL in an M. tuberculosis lineage other than L2. Such differences may be important for the evolution of L1 strains, e.g., allowing adaption to different human populations.
ABSTRACT
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.
ABSTRACT
COVID-19 has been challenging our society since January 2020. Due to global travel, the new coronavirus has rapidly spread worldwide. This article aims to provide an overview of the challenges in implementing measures in the air and maritime transport sector from the perspective of the German Public Health Service (Öffentlicher Gesundheitsdienst, ÖGD). Significant events and measures for air and maritime transport between January and August 2020 were selected. Lessons learned are discussed.During the COVID-19 pandemic, the ÖGD has been operating in a field of tension between the dynamics of scientific knowledge, political decision-making, social acceptance and consent.There are specific challenges at points of entry such as airports and seaports. These include staff shortages and the need to implement measures with a high organisational effort at very short notice such as health authority passenger checks carried out on aircraft, the establishment of test centres at points of entry and control of compliance with quarantine measures. Aggravating the situation, passenger lists, which are necessary for effective contact tracing, are often not available or incomplete. There is also a lack of digital tools for contact tracing but also, for example, the exchange of personal data within the ÖGD. Further difficulties in outbreak management arise from the cramped conditions on board ships and from the potential psychological stress on crew members and passengers, which have not yet been sufficiently considered.In view of all these challenges, it is paramount to strengthen the German Public Health Service in general and at points of entry and to intensify the exchange between the national, federal state and local levels.
