Low prevalence of Chlamydia trachomatis infection in asymptomatic young Swiss men

BACKGROUND: Prevalence and risk factors for Chlamydia trachomatis infection among young men in Switzerland is still unknown. The objective of the present study was to assess prevalence and risk factors for C. trachomatis infection in young Swiss men. METHODS: 517 young Swiss men were enrolled in this cross-sectional study during their compulsory military recruitment. Participants completed a questionnaire and gave urine samples which were screened for C. trachomatis DNA by PCR. Genotyping of positive samples was done by amplification and sequencing the ompA gene. RESULTS: The prevalence of chlamydial infection among young Swiss male was 1.2% (95% confidence interval [95%CI], 0.4-2.5%). C. trachomatis infection was only identified among the 306 men having multiple sexual partner. Although frequent, neither unprotected sex (absence of condom use), nor alcohol and drug abuse were associated with chlamydial infection. Men living in cities were more frequently infected (2.9%, 95%CI 0.8-7.4%) than men living in rural areas (0.5%, 95%CI 0.1-1.9%, p = 0.046). Moreover, naturalised Swiss citizens were more often positive (4.9%, 95%CI 1.3-12.5%) than native-born Swiss men (0.5%, 95%CI 0.1-1.7%, p = 0.003). CONCLUSION: In comparison with other countries, the prevalence of chlamydial infection in men is extremely low in Switzerland, despite a significant prevalence of risky sexual behaviour. C. trachomatis infection was especially prevalent in men with multiple sexual partners. Further research is required (i) to define which subgroup of the general population should be routinely screened, and (ii) to test whether such a targeted screening strategy will be effective to reduce the prevalence of chlamydial infection among this population

Bifidobacterium longum Bacteremia in Preterm Infants Receiving Probiotics

Administration of probiotics to premature newborns has been shown to prevent necrotizing enterocolitis and reduce all-cause mortality. In our hospital, we documented 2 cases of Bifidobacterium longum subspecies infantis bacteremia in newborns receiving probiotics. By comparative genomics, we confirmed that the strains isolated from each patient originated from the probiotic

Distinct Genomic Features Characterize Two Clades of <i>Corynebacterium diphtheriae</i>: Proposal of <i>Corynebacterium diphtheriae</i> Subsp. <i>diphtheriae</i> Subsp. nov. and <i>Corynebacterium diphtheriae</i> Subsp. <i>lausannense</i> Subsp. nov.

&lt;i&gt;Corynebacterium diphtheriae&lt;/i&gt; is the etiological agent of diphtheria, a disease caused by the presence of the diphtheria toxin. However, an increasing number of records report non-toxigenic &lt;i&gt;C. diphtheriae&lt;/i&gt; infections. Here, a &lt;i&gt;C. diphtheriae&lt;/i&gt; strain was recovered from a patient with a past history of bronchiectasis who developed a severe tracheo-bronchitis with multiple whitish lesions of the distal trachea and the mainstem bronchi. Whole-genome sequencing (WGS), performed in parallel with PCR targeting the toxin gene and the Elek test, provided clinically relevant results in a short turnaround time, showing that the isolate was non-toxigenic. A comparative genomic analysis of the new strain (CHUV2995) with 56 other publicly available genomes of &lt;i&gt;C. diphtheriae&lt;/i&gt; revealed that the strains CHUV2995, CCUG 5865 and CMCNS703 share a lower average nucleotide identity (ANI) (95.24 to 95.39%) with the &lt;i&gt;C. diphtheriae&lt;/i&gt; NCTC 11397 &lt;sup&gt;T&lt;/sup&gt; reference genome than all other &lt;i&gt;C. diphtheriae&lt;/i&gt; genomes (&gt;98.15%). Core genome phylogeny confirmed the presence of two monophyletic clades. Based on these findings, we propose here two new &lt;i&gt;C. diphtheriae&lt;/i&gt; subspecies to replace the lineage denomination used in previous multilocus sequence typing studies: &lt;i&gt;C. diphtheriae&lt;/i&gt; subsp. &lt;i&gt;lausannense&lt;/i&gt; subsp. nov. (instead of lineage-2), regrouping strains CHUV2995, CCUG 5865, and CMCNS703, and &lt;i&gt;C. diphtheriae&lt;/i&gt; subsp. &lt;i&gt;diphtheriae&lt;/i&gt; subsp. nov, regrouping all other &lt;i&gt;C. diphtheriae&lt;/i&gt; in the dataset (instead of lineage-1). Interestingly, members of subspecies &lt;i&gt;lausannense&lt;/i&gt; displayed a larger genome size than subspecies &lt;i&gt;diphtheriae&lt;/i&gt; and were enriched in COG categories related to transport and metabolism of lipids (I) and inorganic ion (P). Conversely, they lacked all genes involved in the synthesis of pili (SpaA-type, SpaD-type and SpaH-type), molybdenum cofactor and of the nitrate reductase. Finally, the CHUV2995 genome is particularly enriched in mobility genes and harbors several prophages. The genome encodes a type II-C CRISPR-Cas locus with 2 spacers that lacks &lt;i&gt;csn2&lt;/i&gt; or &lt;i&gt;cas4&lt;/i&gt; , which could hamper the acquisition of new spacers and render strain CHUV2995 more susceptible to bacteriophage infections and gene acquisition through various mechanisms of horizontal gene transfer

High Throughput Sequencing and Proteomics to Identify Immunogenic Proteins of a New Pathogen: The Dirty Genome Approach

BACKGROUND:With the availability of new generation sequencing technologies, bacterial genome projects have undergone a major boost. Still, chromosome completion needs a costly and time-consuming gap closure, especially when containing highly repetitive elements. However, incomplete genome data may be sufficiently informative to derive the pursued information. For emerging pathogens, i.e. newly identified pathogens, lack of release of genome data during gap closure stage is clearly medically counterproductive. METHODS/PRINCIPAL FINDINGS:We thus investigated the feasibility of a dirty genome approach, i.e. the release of unfinished genome sequences to develop serological diagnostic tools. We showed that almost the whole genome sequence of the emerging pathogen Parachlamydia acanthamoebae was retrieved even with relatively short reads from Genome Sequencer 20 and Solexa. The bacterial proteome was analyzed to select immunogenic proteins, which were then expressed and used to elaborate the first steps of an ELISA. CONCLUSIONS/SIGNIFICANCE:This work constitutes the proof of principle for a dirty genome approach, i.e. the use of unfinished genome sequences of pathogenic bacteria, coupled with proteomics to rapidly identify new immunogenic proteins useful to develop in the future specific diagnostic tests such as ELISA, immunohistochemistry and direct antigen detection. Although applied here to an emerging pathogen, this combined dirty genome sequencing/proteomic approach may be used for any pathogen for which better diagnostics are needed. These genome sequences may also be very useful to develop DNA based diagnostic tests. All these diagnostic tools will allow further evaluations of the pathogenic potential of this obligate intracellular bacterium

Crescent and star shapes of members of the Chlamydiales order: impact of fixative methods

Members of the Chlamydiales order all share a biphasic lifecycle alternating between small infectious particles, the elementary bodies (EBs) and larger intracellular forms able to replicate, the reticulate bodies. Whereas the classical Chlamydia usually harbours round-shaped EBs, some members of the Chlamydia-related families display crescent and star-shaped morphologies by electron microscopy. To determine the impact of fixative methods on the shape of the bacterial cells, different buffer and fixative combinations were tested on purified EBs of Criblamydia sequanensis, Estrella lausannensis, Parachlamydia acanthamoebae, and Waddlia chondrophila. A linear discriminant analysis was performed on particle metrics extracted from electron microscopy images to recognize crescent, round, star and intermediary forms. Depending on the buffer and fixatives used, a mixture of alternative shapes were observed in varying proportions with stars and crescents being more frequent in C. sequanensis and P. acanthamoebae, respectively. No tested buffer and chemical fixative preserved ideally the round shape of a majority of bacteria and other methods such as deep-freezing and cryofixation should be applied. Although crescent and star shapes could represent a fixation artifact, they certainly point towards a diverse composition and organization of membrane proteins or intracellular structures rather than being a distinct developmental stag

Growth, electronic and electrical characterization of Ge-Rich Ge-Sb-Te alloy

In this study, we deposit a Ge-rich Ge-Sb-Te alloy by physical vapor deposition (PVD) in the amorphous phase on silicon substrates. We study in-situ, by X-ray and ultraviolet photoemission spectroscopies (XPS and UPS), the electronic properties and carefully ascertain the alloy composition to be GST 29 20 28. Subsequently, Raman spectroscopy is employed to corroborate the results from the photoemission study. X-ray diffraction is used upon annealing to study the crystallization of such an alloy and identify the effects of phase separation and segregation of crystalline Ge with the formation of grains along the [111] direction, as expected for such Ge-rich Ge-Sb-Te alloys. In addition, we report on the electrical characterization of single memory cells containing the Ge-rich Ge-Sb-Te alloy, including I-V characteristic curves, programming curves, and SET and RESET operation performance, as well as upon annealing temperature. A fair alignment of the electrical parameters with the current state-of-the-art of conventional (GeTe)n-(Sb2Te3)m alloys, deposited by PVD, is found, but with enhanced thermal stability, which allows for data retention up to 230 °C

Insight into cross-talk between intra-amoebal pathogens

Abstract: Background: Amoebae are phagocytic protists where genetic exchanges might take place between amoeba-resistant bacteria. These amoebal pathogens are able to escape the phagocytic behaviour of their host. They belong to different bacterial phyla and often show a larger genome size than human-infecting pathogens. This characteristic is proposed to be the result of frequent gene exchanges with other bacteria that share a sympatric lifestyle and contrasts with the genome reduction observed among strict human pathogens.Results: We sequenced the genome of a new amoebal pathogen, Legionella drancourtii, and compared its gene content to that of a Chlamydia-related bacterium, Parachlamydia acanthamoebae. Phylogenetic reconstructions identified seven potential horizontal gene transfers (HGTs) between the two amoeba-resistant bacteria, including a complete operon of four genes that encodes an ABC-type transporter. These comparisons pinpointed potential cases of gene exchange between P. acanthamoebae and Legionella pneumophila, as well as gene exchanges between other members of the Legionellales and Chlamydiales orders. Moreover, nine cases represent possible HGTs between representatives from the Legionellales or Chlamydiales and members of the Rickettsiales order.Conclusions: This study identifies numerous gene exchanges between intracellular Legionellales and Chlamydiales bacteria, which could preferentially occur within common inclusions in their amoebal hosts. Therefore it contributes to improve our knowledge on the intra-amoebal gene properties associated to their specific lifestyle

Accelerated versus standard epirubicin followed by cyclophosphamide, methotrexate, and fluorouracil or capecitabine as adjuvant therapy for breast cancer in the randomised UK TACT2 trial (CRUK/05/19): a multicentre, phase 3, open-label, randomised, controlled trial.

BACKGROUND: Adjuvant chemotherapy for early breast cancer has improved outcomes but causes toxicity. The UK TACT2 trial used a 2×2 factorial design to test two hypotheses: whether use of accelerated epirubicin would improve time to tumour recurrence (TTR); and whether use of oral capecitabine instead of cyclophosphamide would be non-inferior in terms of patients' outcomes and would improve toxicity, quality of life, or both. METHODS: In this multicentre, phase 3, randomised, controlled trial, we enrolled patients aged 18 years or older from 129 UK centres who had histologically confirmed node-positive or high-risk node-negative operable breast cancer, had undergone complete excision, and were due to receive adjuvant chemotherapy. Patients were randomly assigned to receive four cycles of 100 mg/m2 epirubicin either every 3 weeks (standard epirubicin) or every 2 weeks with 6 mg pegfilgrastim on day 2 of each cycle (accelerated epirubicin), followed by four 4-week cycles of either classic cyclophosphamide, methotrexate, and fluorouracil (CMF; 600 mg/m2 cyclophosphamide intravenously on days 1 and 8 or 100 mg/m2 orally on days 1-14; 40 mg/m2 methotrexate intravenously on days 1 and 8; and 600 mg/m2 fluorouracil intravenously on days 1 and 8 of each cycle) or four 3-week cycles of 2500 mg/m2 capecitabine (1250 mg/m2 given twice daily on days 1-14 of each cycle). The randomisation schedule was computer generated in random permuted blocks, stratified by centre, number of nodes involved (none vs one to three vs four or more), age (≤50 years vs >50 years), and planned endocrine treatment (yes vs no). The primary endpoint was TTR, defined as time from randomisation to first invasive relapse or breast cancer death, with intention-to-treat analysis of standard versus accelerated epirubicin and per-protocol analysis of CMF versus capecitabine. This trial is registered with ISRCTN, number 68068041, and with ClinicalTrials.gov, number NCT00301925. FINDINGS: From Dec 16, 2005, to Dec 5, 2008, 4391 patients (4371 women and 20 men) were recruited. At a median follow-up of 85·6 months (IQR 80·6-95·9) no significant difference was seen in the proportions of patients free from TTR events between the accelerated and standard epirubicin groups (overall hazard ratio [HR] 0·94, 95% CI 0·81-1·09; stratified p=0·42). At 5 years, 85·9% (95% CI 84·3-87·3) of patients receiving standard epirubicin and 87·1% (85·6-88·4) of those receiving accelerated epirubicin were free from TTR events. 4358 patients were included in the per-protocol analysis, and no difference was seen in the proportions of patients free from TTR events between the CMF and capecitabine groups (HR 0·98, 95% CI 0·85-1.14; stratified p=0·00092 for non-inferiority). Compared with baseline, significantly more patients taking CMF than those taking capecitabine had clinically relevant worsening of quality of life at end of treatment (255 [58%] of 441 vs 235 [50%] of 475; p=0·011) and at 12 months (114 [34%] of 334 vs 89 [22%] of 401; p<0·001 at 12 months) and had worse quality of life over time (p<0·0001). Detailed toxicity and quality-of-life data were collected from 2115 (48%) of treated patients. The most common grade 3 or higher adverse events in cycles 1-4 were neutropenia (175 [16%]) and fatigue (56 [5%]) of the 1070 patients treated with standard epirubicin, and fatigue (63 [6%]) and infection (34 [3%]) of the 1045 patients treated with accelerated epirubicin. In cycles 5-8, the most common grade 3 or higher adverse events were neutropenia (321 [31%]) and fatigue (109 [11%]) in the patients treated with CMF, and hand-foot syndrome (129 [12%]) and diarrhoea (67 [6%]) in the 1044 patients treated with capcitabine. INTERPRETATION: We found no benefit from increasing the dose density of the anthracycline component of chemotherapy. However, capecitabine could be used in place of CMF without significant loss of efficacy and with improved quality of life. FUNDING: Cancer Research UK, Amgen, Pfizer, and Roche

SARS-CoV-2 N501Y Introductions and Transmissions in Switzerland from Beginning of October 2020 to February 2021—Implementation of Swiss-Wide Diagnostic Screening and Whole Genome Sequencing

The rapid spread of the SARS-CoV-2 lineages B.1.1.7 (N501Y.V1) throughout the UK, B.1.351 (N501Y.V2) in South Africa, and P.1 (B.1.1.28.1; N501Y.V3) in Brazil has led to the definition of variants of concern (VoCs) and recommendations for lineage specific surveillance. In Switzerland, during the last weeks of December 2020, we established a nationwide screening protocol across multiple laboratories, focusing first on epidemiological and microbiological definitions. In January 2021, we validated and implemented an N501Y-specific PCR to rapidly screen for VoCs, which are then confirmed using amplicon sequencing or whole genome sequencing (WGS). A total of 13,387 VoCs have been identified since the detection of the first Swiss case in October 2020, with 4194 being B.1.1.7, 172 B.1.351, and 7 P.1. The remaining 9014 cases of VoCs have been described without further lineage specification. Overall, all diagnostic centers reported a rapid increase of the percentage of detected VOCs, with a range of 6 to 46% between 25 to 31 of January 2021 increasing towards 41 to 82% between 22 to 28 of February. A total of 739 N501Y positive genomes were analysed and show a broad range of introduction events to Switzerland. In this paper, we describe the nationwide coordination and implementation process across laboratories, public health institutions, and researchers, the first results of our N501Y-specific variant screening, and the phylogenetic analysis of all available WGS data in Switzerland, that together identified the early introduction events and subsequent community spreading of the VoCs

The Waddlia Genome: A Window into Chlamydial Biology

Growing evidence suggests that a novel member of the Chlamydiales order, Waddlia chondrophila, is a potential agent of miscarriage in humans and abortion in ruminants. Due to the lack of genetic tools to manipulate chlamydia, genomic analysis is proving to be the most incisive tool in stimulating investigations into the biology of these obligate intracellular bacteria. 454/Roche and Solexa/Illumina technologies were thus used to sequence and assemble de novo the full genome of the first representative of the Waddliaceae family, W. chondrophila. The bacteria possesses a 2′116′312bp chromosome and a 15′593 bp low-copy number plasmid that might integrate into the bacterial chromosome. The Waddlia genome displays numerous repeated sequences indicating different genome dynamics from classical chlamydia which almost completely lack repetitive elements. Moreover, W. chondrophila exhibits many virulence factors also present in classical chlamydia, including a functional type III secretion system, but also a large complement of specific factors for resistance to host or environmental stresses. Large families of outer membrane proteins were identified indicating that these highly immunogenic proteins are not Chlamydiaceae specific and might have been present in their last common ancestor. Enhanced metabolic capability for the synthesis of nucleotides, amino acids, lipids and other co-factors suggests that the common ancestor of the modern Chlamydiales may have been less dependent on their eukaryotic host. The fine-detailed analysis of biosynthetic pathways brings us closer to possibly developing a synthetic medium to grow W. chondrophila, a critical step in the development of genetic tools. As a whole, the availability of the W. chondrophila genome opens new possibilities in Chlamydiales research, providing new insights into the evolution of members of the order Chlamydiales and the biology of the Waddliaceae