We describe a multifactorial investigation of a SARS‐CoV‐2 outbreak in a large meat processing complex in Germany. Infection event timing, spatial, climate and ventilation conditions in the ...processing plant, sharing of living quarters and transport, and viral genome sequences were analyzed. Our results suggest that a single index case transmitted SARS‐CoV‐2 to co‐workers over distances of more than 8 m, within a confined work area in which air is constantly recirculated and cooled. Viral genome sequencing shows that all cases share a set of mutations representing a novel sub‐branch in the SARS‐CoV‐2 C20 clade. We identified the same set of mutations in samples collected in the time period between this initial infection cluster and a subsequent outbreak within the same factory, with the largest number of confirmed SARS‐CoV‐2 cases in a German meat processing facility reported so far. Our results indicate climate conditions, fresh air exchange rates, and airflow as factors that can promote efficient spread of SARS‐CoV‐2 via long distances and provide insights into possible requirements for pandemic mitigation strategies in industrial workplace settings.
Synopsis
There has been considerable debate about the factors contributing to SARS‐CoV‐2 outbreaks in food processing facilities around the world. This multifactorial investigation of an outbreak in a German meat processing plant shows that transmission occurred in a confined working area over long distances.
Analysis of infection event timing, spatial, climate and ventilation conditions, living quarters and transport, and viral genome sequences suggests a super spreading event that originated from a single employee.
Infections among workers over a distance of 8 m from the index case suggest aerosol transmission of SARS‐CoV-2.
The facilities’ environmental conditions such as low temperature, low air exchange rates, and constant air recirculation, together with relatively close distance between workers and demanding physical work, may have promoted efficient aerosol transmission.
In contrast to work‐related exposure, shared apartments, bedrooms, or carpools appear not to have played a major role in the initial outbreak.
Viral genome sequencing reveals a characteristic set of mutations that was also observed in samples collected during a later, much larger outbreak occurring in the same processing plant.
There has been considerable debate about the factors contributing to SARS‐CoV‐2 outbreaks in food processing facilities around the world. This multifactorial investigation of an outbreak in a German meat processing plant shows that transmission occurred in a confined working area over long distances.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We present a new database, specifically devoted to ROS homeostasis regulated proteins. This database replaced our previous database, the PeroxiBase, which was focused only on various peroxidase ...families. The addition of 20 new protein families related with ROS homeostasis justifies the new name for this more complex and comprehensive database as RedoxiBase. Besides enlarging the focus of the database, new analysis tools and functionalities have been developed and integrated through the web interface, with which the users can now directly access to orthologous sequences and see the chromosomal localization of sequences when available. OrthoMCL tool, completed with a post-treatment process, provides precise predictions of orthologous gene groups for the sequences present in this database. In order to explore and analyse orthogroups results, taxonomic visualization of organisms containing sequence of a specific orthogroup as well as chromosomal distribution of the orthogroup with one or two organisms have been included.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cutaneous beta human papillomavirus (HPV) types are suspected to be involved, together with ultraviolet (UV) radiation, in the development of non-melanoma skin cancer (NMSC). Studies in in vitro and ...in vivo experimental models have highlighted the transforming properties of beta HPV E6 and E7 oncoproteins. However, epidemiological findings indicate that beta HPV types may be required only at an initial stage of carcinogenesis, and may become dispensable after full establishment of NMSC. Here, we further investigate the potential role of beta HPVs in NMSC using a Cre-loxP-based transgenic (Tg) mouse model that expresses beta HPV38 E6 and E7 oncogenes in the basal layer of the skin epidermis and is highly susceptible to UV-induced carcinogenesis. Using whole-exome sequencing, we show that, in contrast to WT animals, when exposed to chronic UV irradiation K14 HPV38 E6/E7 Tg mice accumulate a large number of UV-induced DNA mutations, which increase proportionally with the severity of the skin lesions. The mutation pattern detected in the Tg skin lesions closely resembles that detected in human NMSC, with the highest mutation rate in p53 and Notch genes. Using the Cre-lox recombination system, we observed that deletion of the viral oncogenes after development of UV-induced skin lesions did not affect the tumour growth. Together, these findings support the concept that beta HPV types act only at an initial stage of carcinogenesis, by potentiating the deleterious effects of UV radiation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract The small double-stranded DNA polyomaviruses (PyVs) form a family of 73 species, whose natural hosts are primarily mammals and birds. So far, 13 PyVs have been isolated in humans, and some ...of them have clearly been associated with several diseases, including cancer. In this study, we describe the isolation of a novel PyV in human skin using a sensitive degenerate PCR protocol combined with next-generation sequencing. The new virus, named Lyon IARC PyV (LIPyV), has a circular genome of 5269 nucleotides. Phylogenetic analyses showed that LIPyV is related to the raccoon PyV identified in neuroglial tumours in free-ranging raccoons. Analysis of human specimens from cancer-free individuals showed that 9 skin swabs (9/445; 2.0%), 3 oral gargles (3/140; 2.1%), and one eyebrow hair sample (1/439; 0.2%) tested positive for LIPyV. Future biological and epidemiological studies are needed to confirm the human tropism and provide insights into its biological properties.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Tumor suppressors can exert pro-proliferation functions in specific contexts. In the beta human papillomavirus type 38 (HPV38) experimental model, the viral proteins E6 and E7 promote accumulation of ...a wild-type (WT) p53 form in human keratinocytes (HKs), promoting cellular proliferation. Inactivation of p53 by different means strongly decreases the proliferation of HPV38 E6/E7 HKs. This p53 form is phosphorylated at S392 by the double-stranded RNA-dependent protein kinase PKR, which is highly activated by HPV38. PKR-mediated S392 p53 phosphorylation promotes the formation of a p53/DNMT1 complex, which inhibits expression of integrin alpha 1 (ITGA1), a repressor of epidermal growth factor receptor (EGFR) signaling. Ectopic expression of ITGA1 in HPV38 E6/E7 HKs promotes EGFR degradation, inhibition of cellular proliferation, and cellular death. Itga1 expression was also inhibited in the skin of HPV38 transgenic mice that have an elevated susceptibility to UV-induced skin carcinogenesis. In summary, these findings reveal the existence of a specific WT p53 form that displays pro-proliferation properties.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The histone modifier lysine (K)-specific demethylase 2B (KDM2B) plays a role in the differentiation of hematopoietic cells, and its expression appears to be deregulated in certain cancers of ...hematological and lymphoid origins. We have previously found that the
gene is differentially methylated in cell lines derived from Epstein-Barr virus (EBV)-associated endemic Burkitt lymphoma (eBL) compared with that in EBV-negative sporadic Burkitt lymphoma-derived cells. However, whether KDM2B plays a role in eBL development has not been previously investigated. Oncogenic viruses have been shown to hijack the host cell epigenome to complete their life cycle and to promote the transformation process by perturbing cell chromatin organization. Here, we investigated whether EBV alters KDM2B levels to enable its life cycle and promote B-cell transformation. We show that infection of B cells with EBV leads to downregulation of KDM2B levels. We also show that LMP1, one of the main EBV transforming proteins, induces increased DNMT1 recruitment to the
gene and augments its methylation. By altering KDM2B levels and performing chromatin immunoprecipitation in EBV-infected B cells, we show that KDM2B is recruited to the EBV gene promoters and inhibits their expression. Furthermore, forced KDM2B expression in immortalized B cells led to altered mRNA levels of some differentiation-related genes. Our data show that EBV deregulates KDM2B levels through an epigenetic mechanism and provide evidence for a role of KDM2B in regulating virus and host cell gene expression, warranting further investigations to assess the role of KDM2B in the process of EBV-mediated lymphomagenesis.
In Africa, Epstein-Barr virus infection is associated with endemic Burkitt lymphoma, a pediatric cancer. The molecular events leading to its development are poorly understood compared with those leading to sporadic Burkitt lymphoma. In a previous study, by analyzing the DNA methylation changes in endemic compared with sporadic Burkitt lymphoma cell lines, we identified several differential methylated genomic positions in the proximity of genes with a potential role in cancer, and among them was the
gene.
encodes a histone H3 demethylase already shown to be involved in some hematological disorders. However, whether KDM2B plays a role in the development of Epstein-Barr virus-mediated lymphoma has not been investigated before. In this study, we show that Epstein-Barr virus deregulates KDM2B expression and describe the underlying mechanisms. We also reveal a role of the demethylase in controlling viral and B-cell gene expression, thus highlighting a novel interaction between the virus and the cellular epigenome.
The detection of known human papillomaviruses (PVs) from targeted wet-lab approaches has traditionally used PCR-based methods coupled with Sanger sequencing. With the introduction of next-generation ...sequencing (NGS), these approaches can be revisited to integrate the sequencing power of NGS. Although computational tools have been developed for metagenomic approaches to search for known or novel viruses in NGS data, no appropriate tool is available for the classification and identification of novel viral sequences from data produced by amplicon-based methods.
We have developed PVAmpliconFinder, a data analysis workflow designed to rapidly identify and classify known and potentially new Papillomaviridae sequences from NGS amplicon sequencing with degenerate PV primers. Here, we describe the features of PVAmpliconFinder and its implementation using biological data obtained from amplicon sequencing of human skin swab specimens and oral rinses from healthy individuals.
PVAmpliconFinder identified putative new HPV sequences, including one that was validated by wet-lab experiments. PVAmpliconFinder can be easily modified and applied to other viral families. PVAmpliconFinder addresses a gap by providing a solution for the analysis of NGS amplicon sequencing, increasingly used in clinical research. The PVAmpliconFinder workflow, along with its source code, is freely available on the GitHub platform: https://github.com/IARCbioinfo/PVAmpliconFinder.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
So far, only a few reports about reinfections with SARS-CoV-2 have been published, and they often lack detailed immunological and virological data. We report about a SARS-CoV-2 reinfection with a ...genetically distinct SARS-CoV-2 variant in an immunocompetent female healthcare worker that has led to a mild disease course. No obvious viral escape mutations were observed in the second virus variant. The infectious virus was shed from the patient during the second infection episode despite the presence of neutralizing antibodies in her blood. Our data indicate that a moderate immune response after the first infection, but not a viral escape, did allow for reinfection and live virus shedding.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The recently emerged SARS-CoV-2 B.1.1.529 lineage and its sublineages (Omicron variant) pose a new challenge to healthcare systems worldwide due to its ability to efficiently spread in immunized ...populations and its resistance to currently available monoclonal antibody therapies. RT-PCR-based variant tests can be used to screen large sample-sets rapidly and accurately for relevant variants of concern (VOC). The aim of this study was to establish and validate a multiplex assay on the cobas 6800/8800 systems to allow discrimination between the two currently circulating VOCs, Omicron and Delta, in clinical samples.
Primers and probes were evaluated for multiplex compatibility. Analytic performance was assessed using cell culture supernatant of an Omicron variant isolate and a clinical Delta variant sample, normalized to WHO-Standard. Clinical performance of the multiplex assay was benchmarked against NGS results.
In silico testing of all oligos showed no interactions with a high risk of primer-dimer formation or amplification of human DNA/RNA. Over 99.9% of all currently available Omicron variant sequences are a perfect match for at least one of the three Omicron targets included in the multiplex. Analytic sensitivity was determined as 19.0 IU/mL (CI95%: 12.9-132.2 IU/mL) for the A67V + del-HV69-70 target, 193.9 IU/mL (CI95%: 144.7-334.7 IU/mL) for the E484A target, 35.5 IU/mL (CI95%: 23.3-158.0 IU/mL) for the N679K + P681H target and 105.0 IU/mL (CI95%: 80.7-129.3 IU/mL) for the P681R target. All sequence variances were correctly detected in the clinical sample set (225/225 Targets).
RT-PCR-based variant screening compared to whole genome sequencing is both rapid and reliable in detecting relevant sequence variations in SARS-CoV-2 positive samples to exclude or verify relevant VOCs. This allows short-term decision-making, e.g., for patient treatment or public health measures.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Human papillomavirus type 16 (HPV16) and other oncoviruses have been shown to block innate immune responses and to persist in the host. However, to avoid viral persistence, the immune response ...attempts to clear the infection. IL-1β is a powerful cytokine produced when viral motifs are sensed by innate receptors that are members of the inflammasome family. Whether oncoviruses such as HPV16 can activate the inflammasome pathway remains unknown. Here, we show that infection of human keratinocytes with HPV16 induced the secretion of IL-1β. Yet, upon expression of the viral early genes, IL-1β transcription was blocked. We went on to show that expression of the viral oncoprotein E6 in human keratinocytes inhibited IRF6 transcription which we revealed regulated IL-1β promoter activity. Preventing E6 expression using siRNA, or using E6 mutants that prevented degradation of p53, showed that p53 regulated IRF6 transcription. HPV16 abrogation of p53 binding to the IRF6 promoter was shown by ChIP in tissues from patients with cervical cancer. Thus E6 inhibition of IRF6 is an escape strategy used by HPV16 to block the production IL-1β. Our findings reveal a struggle between oncoviral persistence and host immunity; which is centered on IL-1β regulation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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