Introduction. Streptococcus uberis is a common cause of mastitis in cattle, leading to significant economic losses. The widespread use of antimicrobials has contributed to the emergence of resistance, which poses a severe challenge in controlling S. uberis infection. Aim. The objective of this study was to gain insights into the antimicrobial resistance (AMR) and epidemiological typing of S. uberis isolated from milk collected from bovine mastitis on dairy farms in Thuringia. Methodology. In this study, 84 S. uberis isolates were obtained from cattle with clinical mastitis in Thuringia, their phenotypic and genotypic AMR were analyzed and their phylogenetic relationship was explored using whole-genome sequencing. Results. Genetically heterogeneous strains were found on the farms, but clusters of highly similar strains also circulated within the same farms. All isolates were sensitive to ampicillin, penicillin, ceftiofur, and vancomycin. However, 42.9%, 42.9%, 22.6%, 19.0%, and 13.0% were resistant to tetracycline, doxycycline, clindamycin, pirlimycin, and erythromycin, respectively. Thirty-nine strains were phenotypically resistant to two or more tested antibiotics. We identified a plasmid associated with macrolide and lincosamide resistance in 12% of the strains. Conclusion. The emergence of S. uberis strains resistant to multiple antibiotics highlights the importance of S. uberis surveillance and the prudent use of antimicrobials.
Food and waterborne disease (FWD) surveillance requires Whole-Genome Sequencing (WGS)-based systems following a One Health approach. However, different laboratories employ different WGS pipelines in their routine surveillance activities, casting doubt on the comparability of their results and hindering optimal communication at intersectoral and international levels. Through a collaborative effort involving eleven European institutes across seven countries and spanning the food, animal and human health sectors, we aimed to assess the inter-laboratory comparability of WGS clustering results for four important foodborne pathogens: Listeria monocytogenes, Salmonella enterica, Escherichia coli and Campylobacter jejuni. Each participating institute (n=9) applied its surveillance pipeline over the same WGS datasets (>2000 isolates per species), and, for each pipeline, genetic clusters were identified at each possible allele/SNP distance threshold. Inter-pipeline clustering congruence was assessed by calculating a Congruence Score (relying on Adjusted Wallace and Adjusted Rand coefficients) across all resolution levels, followed by an in-depth comparative analysis of cluster composition at outbreak level. An additional cluster congruence assessment was performed between WGS and traditional typing, which, depending on the species, included Sequence Type (ST), Clonal Complex (CC) and/or serotype. Our results revealed a general high concordance between allele-based pipelines at all resolution levels for all species, except for C. jejuni, where the different resolution power of available allele-based schemas led to marked discrepancies. Still, this study identified non-negligible differences in allele-based pipeline performance for outbreak cluster detection, suggesting that a threshold flexibilization is important for the detection of similar outbreak signals by different laboratories. These results, together with the observation that different STs, CCs and serotypes exhibit remarkably different genetic diversity, should inform future threshold selections for outbreak case definitions. In conclusion, this study provides valuable insights into the comparability of pipelines commonly used for routine genomics surveillance, and reinforces the need, while demonstrating the feasibility, of conducting continuous and comprehensive WGS pipeline comparability assessments. Ultimately, it opens good perspectives for a smoother international and intersectoral cooperation and communication towards a sustainable and efficient One Health FWD surveillance. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by co-funding from the European Union's Horizon 2020 Research and Innovation program under grant agreement No 773830: One Health European Joint Programme (2020 to 2022) (https://onehealthejp.eu/projects/foodborne-zoonoses/jrp-beone) and by the ISIDORe project (funding from the European Union's Horizon Europe Research & Innovation Programme, Grant Agreement no. 101046133). VM contribution was funded by national funds through FCT - Foundation for Science and Technology, I.P., in the frame of Individual CEEC 2022.00851.CEECIND/CP1748/CT0001 (2023 onwards). JDS contribution was supported by the project "Sustainable use and integration of enhanced infrastructure into routine genome-based surveillance and outbreak investigation activities in Portugal" (GENEO, https://www.insa.min-saude.pt/category/projectos/geneo/) on behalf of the EU4H programme (EU4H-2022-DGA-MS-IBA-1). Research at the National Veterinary Research Institute (PIWet) Poland was supported by the Polish Ministry of Education and Science from the funds for science in the years 2018-2022 allocated for the implementation of a co-financed international project. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Anonymized sequencing reads of the BeONE dataset are deposited in the European Nucleotide Archive (ENA) database under the BioProjects PRJEB57166, PRJEB57179, PRJEB57098 and PRJEB57119. Genome assemblies are deposited in the Zenodo repository (L. monocytogenes: 10.5281/ZENODO.7267486; S. enterica: 10.5281/ZENODO.7267785; E. coli: 10.5281/ZENODO.7267844; C. jejuni: 10.5281/ZENODO.7267879). The public dataset data was retrieved from Zenodo (L. monocytogenes: 10.5281/ZENODO.7116878; S. enterica: 10.5281/ZENODO.7119735; E. coli: 10.5281/ZENODO.7120057; C. jejuni: 10.5281/ZENODO.7120166). The collection of scripts used to conduct these analyses are available at the github repository https://github.com/insapathogenomics/WGS\_cluster\_congruence. Supplementary data are available in the Zenodo repository (https://doi.org/10.5281/zenodo.12805750).
Campylobacter (C.) jejuni is a zoonotic bacterium of public health significance. The present investigation was designed to assess the epidemiology and genetic heterogeneity of C. jejuni recovered from commercial turkey farms in Germany using whole-genome sequencing. The Illumina MiSeq® technology was used to sequence 66 C. jejuni isolates obtained between 2010 and 2011 from commercial meat turkey flocks located in ten German federal states. Phenotypic antimicrobial resistance was determined. Phylogeny, resistome, plasmidome and virulome profiles were analyzed using whole-genome sequencing data. Genetic resistance markers were identified with bioinformatics tools (AMRFinder, ResFinder, NCBI and ABRicate) and compared with the phenotypic antimicrobial resistance. The isolates were assigned to 28 different sequence types and 11 clonal complexes. The average pairwise single nucleotide-polymorphisms distance of 14,585 SNPs (range: 0–26,540 SNPs) revealed a high genetic distinction between the isolates. Thirteen virulence-associated genes were identified in C. jejuni isolates. Most of the isolates harbored the genes flaA (83.3%) and flaB (78.8%). The wlaN gene associated with the Guillain–Barré syndrome was detected in nine (13.6%) isolates. The genes for resistance to ampicillin (blaOXA), tetracycline [tet(O)], neomycin [aph(3')-IIIa], streptomycin (aadE) and streptothricin (sat4) were detected in isolated C. jejuni using WGS. A gene cluster comprising the genes sat4, aph(3′)-IIIa and aadE was present in six isolates. The single point mutation T86I in the housekeeping gene gyrA conferring resistance to quinolones was retrieved in 93.6% of phenotypically fluoroquinolone-resistant isolates. Five phenotypically erythromycin-susceptible isolates carried the mutation A103V in the gene for the ribosomal protein L22 inferring macrolide resistance. An assortment of 13 β-lactam resistance genes (blaOXA variants) was detected in 58 C. jejuni isolates. Out of 66 sequenced isolates, 28 (42.4%) carried plasmid-borne contigs. Six isolates harbored a pTet-like plasmid-borne contig which carries the tet(O) gene. This study emphasized the potential of whole-genome sequencing to ameliorate the routine surveillance of C. jejuni. Whole-genome sequencing can predict antimicrobial resistance with a high degree of accuracy. However, resistance gene databases need curation and updates to revoke inaccuracy when using WGS-based analysis pipelines for AMR detection.
Salmonella enterica subspecies enterica serovar Dublin (S. Dublin) is a host-adapted serovar causing enteritis and/or systemic diseases in cattle. As the serovar is not host-restricted, it may cause infections in other animals, including humans with severe illness and higher mortality rates than other non-typhoidal serovars. As human infections are mainly caused by contaminated milk, milk products and beef, information on the genetic relationship of S. Dublin strains from cattle and food should be evaluated. Whole-genome sequencing (WGS) of 144 S. Dublin strains from cattle and 30 strains from food origin was performed. Multilocus sequence typing (MLST) revealed mostly sequence type ST-10 from both, cattle and food isolates. In total, 14 of 30 strains from food origin were clonally related to at least one strain from cattle, as detected by core-genome single nucleotide polymorphisms typing as well as core-genome MLST. The remaining 16 foodborne strains fit into the genome structure of S. Dublin in Germany without outliers. WGS proved to be a powerful tool not only to gain information on the epidemiology of Salmonella strains but also to detect clonal relations between organisms isolated from different stages of production. This study has shown a high genetic correlation between S. Dublin strains from cattle and food and, therefore, the potential to cause human infections. S. Dublin strains of both origins share an almost identical set of virulence factors, emphasizing their potential to cause severe clinical manifestations in animals, but also in humans and thus the need for effective control of S. Dublin in a farm-to-fork strategy.
Bacteria of the genus Salmonella pose a major risk to livestock, the food economy, and public health. Salmonella infections are one of the leading causes of food poisoning. The identification of serovars of Salmonella achieved by their diverse surface antigens is essential to gain information on their epidemiological context. Traditionally, slide agglutination has been used for serotyping. In recent years, whole-genome sequencing (WGS) followed by in silico serotyping has been established as an alternative method for serotyping and the detection of genetic markers for Salmonella. Until now, WGS data generated with Illumina sequencing are used to validate in silico serotyping methods. Oxford Nanopore Technologies (ONT) opens the possibility to sequence ultra-long reads and has frequently been used for bacterial sequencing. In this study, ONT sequencing data of 28 Salmonella strains of different serovars with epidemiological relevance in humans, food, and animals were taken to investigate the performance of the in silico serotyping tools SISTR and SeqSero2 compared to traditional slide agglutination tests. Moreover, the detection of genetic markers for resistance against antimicrobial agents, virulence, and plasmids was studied by comparing WGS data based on ONT with WGS data based on Illumina. Based on the ONT data from flow cell version R9.4.1, in silico serotyping achieved an accuracy of 96.4 and 92% for the tools SISTR and SeqSero2, respectively. Highly similar sets of genetic markers comparing both sequencing technologies were identified. Taking the ongoing improvement of basecalling and flow cells into account, ONT data can be used for Salmonella in silico serotyping and genetic marker detection.
Bacillus cereus is a ubiquitous spore-forming bacterium causing food spoilage. In this study, seventeen B. cereus were isolated from dairy processing equipment in Algeria and characterized. The pathogenic potential genes encoding hemolysin, nonhaemolytic enterotoxin, cytotoxin K and emetic toxin were investigated by PCR. Phylogeny and genetic markers for antimicrobial resistance and virulence were analyzed using whole-genome sequencing data using the Illumina MiSeq® technology. The identity of the isolated strains was confirmed as B. cereus sensu lato and the sequencing of the panC gene clustered 64.7% of them in phylogenetic group III and 35.3% in group IV. The results of PFGE showed that 8 (47.1%), 4 (23.5%), 3 (17.6%) and 2 (11.8%) were differentiated into four groups A, B, C and D, respectively. Each of the two panC phylogenetic groups contains two different types of isolates corresponding to PFGE group (A and C) and (B and D) for phylogenetic groups III and IV, respectively. None of the 14 isolates carried the emetic toxin (ces) gene, whereas other toxin genes were variably detected. Genotyping assigned all isolates to three different sequence types (ST 2226, ST1018 and ST1431) while one clonal complex (CC-142) was identified in three isolates. Hierarchical clustering with a threshold of 500 core genome single nucleotide polymorphism (cgSNPs) differences grouped the strains into three clusters while two strains were less than 20 SNPs different. Three B. cereus (25%) contained three enterotoxic HBL complex-encoding genes hblA/C/D. Enterotoxic NHE complex-encoding genes (nheA/B/C) and the ctyK1 gene were detected in all isolates. The overall results highlight the risk due to toxins produced by the B. cereus group in the food safety and dairy industries in Algeria. This study emphasized the potential of whole-genome sequencing for genotyping and predicting the virulence-associated genes and antimicrobial resistance. The present study will help to better assess the health and spoilage risk associated with B. cereus in dairy processing plants and to incorporate adequate preventive measures.
In 2021, a white-handed gibbon (Hylobates lar) succumbed to illness shortly after transfer from one zoo to another in Germany, due to Francisella tularensis subsp. holarctica infection. To determine the source of infection, whole genome sequencing of the gibbon-derived isolate was performed and wild pest rodents (and captive squirrels) from both zoos were screened for F. tularensis. The F. tularensis whole genome sequence obtained from the gibbon was closely related to previous subclade B.281 sequences obtained from hares from Baden-Wuerttemberg, the same region where the gibbon was first housed. However, F. tularensis DNA was detected in one Norway rat from the receiving zoo. Therefore, neither zoo can be excluded as the source of infection.
The cattle-adapted serovar Salmonella Dublin (S. Dublin) causes enteritis and systemic diseases in animals. In the German federal state Schleswig-Holstein, S. Dublin is the most important serovar in cattle indicating an endemic character of the infection. To gain information on dissemination and routes of infection, whole-genome sequencing (WGS) was used to explore the genetic traits of 78 S. Dublin strains collected over a period of six years. The phylogeny was analysed using core-genome single nucleotide polymorphisms (cgSNPs). Genomic clusters at 100, 15 and 1 cgSNPs were selected for molecular analysis. Important specific virulence determinants were detected in all strains but multidrug resistance in S. Dublin organisms was not found. Using 15 cgSNPs epidemiological links between herds were identified, clusters at 1 cgSNPs provided clear evidence on both persistence of S. Dublin at single farms in consecutive years and transmission of the organisms between herds in different distances. A possible risk factor for the repeated occurrence of S. Dublin in certain districts of Schleswig-Holstein might be the spreading of manure on pastures and grassland. Effective control of S. Dublin requires farm-specific analysis of the management supplemented by WGS of outbreak causing S. Dublin strains to clearly identify routes of infection.
Campylobacter fetus subsp. venerealis (Cfv) causes bovine genital campylobacteriosis (BGC), a World Organization for Animal Health (WOAH)-listed trade-relevant disease characterized by severe reproductive losses, such as infertility, early embryonic death and abortion in cattle. BGC has significant economic implications that have prompted several countries to adopt stringent eradication and surveillance measures to contain the disease. In Germany, there has been a low incidence of BGC cases over the past 28 years. This study aimed to illustrate the genomic diversity of German Cfv strains isolated from different federal states in Germany. This study analyzed 63 Cfv strains, collected between 1985 and 2015, by whole-genome sequencing and compared them with genome data of 91 international Cfv isolates. The phylogenetic analysis showed that the Cfv population is genetically conserved and has geographic clusters. In Germany, one phylogenetic lineage comprising all strains was identified. This German lineage was part of a subclade that probably emerged in the nineteenth century and diversified over time. The results of this study point to a non-recurrent cross-border introduction of Cfv in Germany. The BGC control interventions in Germany can be considered successful as no outbreaks were reported since 2015.
The current COVID-19 pandemic highlights the importance of novel molecular technologies and methods for rapid pathogen control (Hufsky et al., 2021). In just a few days, South African researchers recently succeeded in sharing crucial sequence information about another worrisome SARS-CoV-2 variant, now called Omicron helping several countries to monitor and contain this viral variant more quickly (Abdool Karim and Abdool Karim, 2021; Torjesen, 2021). This showcase illustrates that the broad application of sequencing technologies has significantly expanded our portfolio to analyze microbes and the responses of their hosts to health and disease (Gardy and Nicholas, 2018; Gwinn et al., 2019). Researchers analyze isolates, metagenomic and metatranscriptomic samples from various environmental settings, including human, animal, and agricultural environments. The possibility to perform real-time sequencing and data analysis opens up entirely new applications in the field of molecular surveillance and outbreak analysis (Wang et al., 2021). We never before had access to such quantity and quality of tools for molecular monitoring of (emerging) pathogens, mobile genetic elements, virulence and resistance factors, and antibiotic resistance genes. This Research Topic collects contributions at the edge of the transition era to new sequencing technologies and their application to integrative omics in molecular surveillance (Figure 1). The selected articles address various areas of molecular surveillance in human health, animal health, food safety, and related fields using established short-read and novel long-read sequencing technologies as well as integration of multiple omics data sources. The included studies highlight the challenges, limitations, and future aspects of sequencing and multi-omics-based microbial characterization, particularly in the context of molecular surveillance. Our journey into the era of new sequencing technologies begins with the monitoring of microbial communities in environmental samples. Studies focus on the detection of unknown microbes, the survey of the global distribution of known taxa, and the causes and implications of the composition of certain microbial communities. As an example, Ríos-Castro et al. use DNA metabarcoding to analyze environmental samples from sediment and marine water samples of a marine ecosystem. They identified pathogens with high relevance for the aquacultural sector and which are of medical and veterinary interest. This study demonstrates the potential of NGS technology for environmental monitoring. Although 16S high-throughput sequencing is widely used worldwide, most protocols do Edited and reviewed by: H. Steven Wiley, Pacific Northwest National Laboratory (DOE), United States
Anthrax is a recurrent zoonosis in the Ukraine with outbreaks occurring repeatedly in certain areas. For determining whether several Bacillus anthracis genotypes are circulating in this region, four strains from various sources isolated from different regions of the Ukraine were investigated. By combining long- and short-read next-generation sequencing techniques, highly accurate genomes were reconstructed, enabling detailed in silico genotyping. Thus, the strains could be assigned to the Tsiankovskii subgroup of the "TransEurAsia" clade, which is commonly found in this region. Their high genetic similarity suggests that the four strains are members of the endemic population whose progenitor was once introduced in the Ukraine and bordering regions. This study provides information on B. anthracis strains from a region where there is little knowledge of the local population, thereby adding to the picture of global B. anthracis genotype distribution. We also emphasize the importance of surveillance and prevention methods regarding anthrax outbreaks, as other studies predicted a higher number of cases in the future due to global warming.
Despite available diagnostic tests and recent advances, diagnosis of pulmonary invasive aspergillosis (IPA) remains challenging. We performed a longitudinal case-control pilot study to identify host-specific, novel, and immune-relevant molecular candidates indicating IPA in patients post allogeneic stem cell transplantation (alloSCT). Supported by differential gene expression analysis of six relevant in vitro studies, we conducted RNA sequencing of three alloSCT patients categorized as probable IPA cases and their matched controls without Aspergillus infection (66 samples in total). We additionally performed immunoassay analysis for all patient samples to gain a multi-omics perspective. Profiling analysis suggested LGALS2, MMP1, IL-8, and caspase-3 as potential host molecular candidates indicating IPA in investigated alloSCT patients. MMP1, IL-8, and caspase-3 were evaluated further in alloSCT patients for their potential to differentiate possible IPA cases and patients suffering from COVID-19-associated pulmonary aspergillosis (CAPA) and appropriate control patients. Possible IPA cases showed differences in IL-8 and caspase-3 serum levels compared with matched controls. Furthermore, we observed significant differences in IL-8 and caspase-3 levels among CAPA patients compared with control patients. With our conceptual work, we demonstrate the potential value of considering the human immune response during Aspergillus infection to identify immune-relevant molecular candidates indicating IPA in alloSCT patients. These human host candidates together with already established fungal biomarkers might improve the accuracy of IPA diagnostic tools.
Burkholderia (B.) mallei is a host-adapted equine pathogen that causes glanders, a re-emerging zoonotic disease, which is endemic in Pakistan and other developing countries and seriously impacts the global equine movement. Due to globalization, the geographical restriction of diseases vanishes and the lack of awareness of and experience with eradicated diseases in industrialized countries also promotes the re-introduction of infections in these regions. Owing to the high equine population, the Pakistani province Punjab is a potential hotspot where several glanders outbreaks have been seen over last two decades. For determining the genomic diversity of B. mallei in this and other equine-populated prefectures, the genomes of 19 B. mallei strains isolated between 1999 and 2020 in different locations were sequenced and their genotypes were determined. Particularly, for genetically highly homogenous pathogens like B. mallei genotyping techniques require a high discriminatory power for enabling differentiation on the strain level. Thus, core-genome single nucleotide polymorphism (cgSNP) analysis was applied for distinguishing the highly similar strains. Furthermore, a whole-genome sequence-based core genome multi locus sequence typing (cgMLST) scheme, specific to B. mallei, was developed and additionally applied to the data. It was found that B. mallei genotypes in Pakistan persisted over time and space and genotype clusters preferred connection with a time point rather than the place of isolation, probably due to frequent equine movement, which promotes the spread of glanders. The cgMLST approach proved to work in accord with SNP typing and may help to investigate future glanders outbreaks.
Salmonella enterica subsp. enterica serovar Dublin is a cattle-adapted serovar that causes enteritis and systemic diseases in animals. In Germany, S. Dublin is not detected or is very rarely detected in some federal states but is endemic in certain regions. Information on detailed genetic characteristics of S. Dublin is not available. An understanding of the paths and spreading of S. Dublin within and between regions and over time is essential to establish effective control strategies. Whole-genome sequencing (WGS) and bioinformatic analysis were used to explore the genetic traits of S. Dublin and to determine their epidemiological context. Seventy-four S. Dublin strains collected in 2005 to 2018 from 10 federal states were studied. The phylogeny was analyzed using core-genome single-nucleotide polymorphisms (cgSNPs) and core-genome multilocus sequence typing. Genomic clusters at 100 cgSNPs, 40 cgSNPs, and 15 cgSNPs were selected for molecular epidemiology. WGS-based genoserotyping confirmed serotyping. Important specific virulence determinants were detected in all strains, but multidrug resistance in German S. Dublin organisms is uncommon. Use of different thresholds for cgSNP analysis enabled a broad view and also a detailed view of the occurrence of S. Dublin in Germany. Genomic clusters could be allocated nationwide, to a limited number of federal states, or to special regions only. Results indicate both persistence and spread of S. Dublin within and between federal states in short and longer time periods. However, to detect possible routes of infection or persistence of S. Dublin indicated by genomic analysis, information on the management of the cattle farms and contacts with corresponding farms are essential. IMPORTANCE Salmonella enterica subsp. enterica serovar Dublin is a bovine host-adapted serovar that causes up to 50% of all registered outbreaks of salmonellosis in cattle in Germany. S. Dublin is not detected or is only rarely detected in some federal states but has been endemic in certain regions of the country for a long time. Information on genetic traits of the causative strains is essential to determine routes of infection. WGS and bioinformatic analysis should be used to explore the genetic characteristics of S. Dublin. Combining the genomic features of S. Dublin strains with information on the management of the cattle farms concerned should enable the detection of possible routes of infection or persistence of S. Dublin. This approach is regarded as a prerequisite to developing effective intervention strategies.
Carbapenem-resistant Acinetobacter baumannii (A. baumannii, CRAb) is an emerging global threat for healthcare systems, particularly in Southeast Asia. Next-generation sequencing (NGS) technology was employed to map genes associated with antimicrobial resistance (AMR) and to identify multilocus sequence types (MLST). Eleven strains isolated from humans in Vietnam were sequenced, and their AMR genes and MLST were compared to published genomes of strains originating from Southeast Asia, i.e., Thailand (n = 49), Myanmar (n = 38), Malaysia (n = 11), Singapore (n = 4) and Taiwan (n = 1). Ten out of eleven Vietnamese strains were CRAb and were susceptible only to colistin. All strains harbored ant(3”)-IIa, armA, aph(6)-Id and aph(3”) genes conferring resistance to aminoglycosides, and blaOXA-51 variants and blaADC-25 conferring resistance to ß-lactams. More than half of the strains harbored genes that confer resistance to tetracyclines, sulfonamides and macrolides. The strains showed high diversity, where six were assigned to sequence type (ST)/2, and two were allocated to two new STs (ST/1411-1412). MLST analyses of 108 strains from Southeast Asia identified 19 sequence types (ST), and ST/2 was the most prevalent found in 62 strains. A broad range of AMR genes was identified mediating resistance to ß-lactams, including cephalosporins and carbapenems (e.g., blaOXA-51-like, blaOXA-23, blaADC-25, blaADC-73, blaTEM-1, blaNDM-1), aminoglycosides (e.g., ant(3”)-IIa, aph(3”)-Ib, aph(6)-Id, armA and aph(3’)-Ia), phenicoles (e.g., catB8), tetracyclines (e.g., tet.B and tet.39), sulfonamides (e.g., sul.1 and sul.2), macrolides and lincosamide (e.g., mph.E, msr.E and abaF). MLST and core genome MLST (cgMLST) showed an extreme diversity among the strains. Several strains isolated from different countries clustered together by cgMLST; however, different clusters shared the same ST. Developing an action plan on AMR, increasing awareness and prohibiting the selling of antibiotics without prescription must be mandatory for this region. Such efforts are critical for enforcing targeted policies on the rational use of carbapenem compounds and controlling AMR dissemination and emergence in general.
Brucellosis is a highly contagious zoonosis that occurs worldwide. Whole-genome sequencing (WGS) has become a widely accepted molecular typing method for outbreak tracing and genomic epidemiology of brucellosis. Twenty-nine Brucella spp. (eight B. abortus biovar 1 and 21 B. melitensis biovar 3) were isolated from lymph nodes, milk, and fetal abomasal contents of infected cattle, buffaloes, sheep, and goats originating from nine districts in Egypt. The isolates were identified by microbiological methods and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Differentiation and genotyping were confirmed using multiplex PCR. Illumina MiSeq® was used to sequence the 29 Brucella isolates. Using MLST typing, ST11 and ST1 were identified among B. melitensis and B. abortus, respectively. Brucella abortus and B. melitensis isolates were divided into two main clusters (clusters 1 and 2) containing two and nine distinct genotypes by core-genome SNP analysis, respectively. The genotypes were irregularly distributed over time and space in the study area. Both Egyptian B. abortus and B. melitensis isolates proved to be genomically unique upon comparison with publicly available sequencing from strains of neighboring Mediterranean, African, and Asian countries. The antimicrobial resistance mechanism caused by mutations in rpoB, gyrA, and gyrB genes associated with rifampicin and ciprofloxacin resistance were identified. To the best of our knowledge, this is the first study investigating the epidemiology of Brucella isolates from livestock belonging to different localities in Egypt based on whole genome analysis.
Anthrax is a serious infectious disease caused by the gram-positive and spore-forming bacterium Bacillus anthracis. In Italy, anthrax is an endemic disease with sporadic cases each year and few outbreaks, especially in Southern Italy. However, new foci have been discovered in zones without previous history of anthrax. During summer 2016, an outbreak of anthrax caused the death of four goats in the Abruzzo region, where the disease had not been reported before. In order to investigate the outbreak, we sequenced one strain and compared it to 19 Italian B. anthracis genomes. Furthermore, we downloaded 71 whole genome sequences representing the global distribution of canonical SNP lineages and used them to verify the phylogenetic positioning. To this end, we analyzed and compared the genome sequences using canonical SNPs and the whole genome SNP-based analysis. Our results demonstrate that the outbreak strain belonged to the Trans-Eurasian (TEA) group A.Br.011/009, which is the predominant clade in Central-Southern Italy. In conclusion, the high genomic relatedness of the Italian TEA strains suggests their evolution from a common ancestor, while the spread is supposedly driven by trade as well as human and transhumance activities. Here, we demonstrated the capabilities of whole genome sequencing (WGS), which can be used as a tool for outbreak analyses and surveillance activities.
Francisella tularensis is the causative agent of the zoonotic disease tularemia. In Germany, most human infections are caused by contact with infected hares. The aim of this study was to characterize Francisella tularensis subsp. holarctica strains isolated from hares in Germany and to develop bioinformatics tools to analyze their genetic relatedness. In total, 257 German isolates—obtained mainly from hares (n = 233), other vertebrate animals, and ticks, but also from humans (n = 3)—were analyzed within this study. Publically available sequence data from 49 isolates were used to put our isolates into an epidemiological context and to compare isolates from natural foci and humans. Whole-genome sequences were analyzed using core-genome Multi-Locus-Sequence-Typing, canonical Single Nucleotide Polymorphism (SNP) typing and whole-genome SNP typing. An overall conformity of genotype clustering between the typing methods was found, albeit with a lower resolution for canonical single SNP typing. The subclade distribution, both on local and national levels, among strains from humans and hares was similar, suggesting circulation of the same genotypes both in animals and humans. Whilst close to identical isolates of the same subclade were found distributed over large areas, small geographical foci often harbored members of different subclades. In conclusion, although genomic high-resolution typing was shown to be robust, reproducible and allowed the identification of highly closely related strains, genetic profiling alone is not always conclusive for epidemiological linkage of F. tularensis strains.
Delayed natural killer (NK) cell reconstitution after allogeneic stem cell transplantation (alloSCT) is associated with a higher risk of developing invasive aspergillosis. The interaction of NK cells with the human pathogen Aspergillus (A.) fumigatus is mediated by the fungal recognition receptor CD56, which is relocated to the fungal interface after contact. Blocking of CD56 signaling inhibits the fungal mediated chemokine secretion of MIP-1α, MIP-1β, and RANTES and reduces cell activation, indicating a functional role of CD56 in fungal recognition. We collected peripheral blood from recipients of an allograft at defined time points after alloSCT (day 60, 90, 120, 180). NK cells were isolated, directly challenged with live A. fumigatus germ tubes, and cell function was analyzed and compared to healthy age and gender-matched individuals. After alloSCT, NK cells displayed a higher percentage of CD56brightCD16dim cells throughout the time of blood collection. However, CD56 binding and relocalization to the fungal contact side were decreased. We were able to correlate this deficiency to the administration of corticosteroid therapy that further negatively influenced the secretion of MIP-1α, MIP-1β, and RANTES. As a consequence, the treatment of healthy NK cells ex vivo with corticosteroids abrogated chemokine secretion measured by multiplex immunoassay. Furthermore, we analyzed NK cells regarding their actin cytoskeleton by Structured Illumination Microscopy (SIM) and flow cytometry and demonstrate an actin dysfunction of NK cells shown by reduced F-actin content after fungal co-cultivation early after alloSCT. This dysfunction remains until 180 days post-alloSCT, concluding that further actin-dependent cellular processes may be negatively influenced after alloSCT. To investigate the molecular pathomechansism, we compared CD56 receptor mobility on the plasma membrane of healthy and alloSCT primary NK cells by single-molecule tracking. The results were very robust and reproducible between tested conditions which point to a different molecular mechanism and emphasize the importance of proper CD56 mobility.
High-throughput RNA sequencing (RNA-seq) is routinely applied to study diverse biological processes; however, when performed separately on interacting organisms, systemic noise intrinsic to RNA extraction, library preparation, and sequencing hampers the identification of cross-species interaction nodes. Here, we develop triple RNA-seq to simultaneously detect transcriptomes of monocyte-derived dendritic cells (moDCs) infected with the frequently co-occurring pulmonary pathogens Aspergillus fumigatus and human cytomegalovirus (CMV). Comparing expression patterns after co-infection with those after single infections, our data reveal synergistic effects and mutual interferences between host responses to the two pathogens. For example, CMV attenuates the fungus-mediated activation of pro-inflammatory cytokines through NF-κB (nuclear factor κB) and NFAT (nuclear factor of activated T cells) cascades, while A. fumigatus impairs viral clearance by counteracting viral nucleic acid-induced activation of type I interferon signaling. Together, the analytical power of triple RNA-seq proposes molecular hubs in the differential moDC response to fungal/viral single infection or co-infection that contribute to our understanding of the etiology and, potentially, clearance of post-transplant infections.