Faecal carriage of enterococci harbouring oxazolidinone resistance genes among healthy humans in the community in Switzerland

Objectives: This study aimed to investigate the faecal carriage of enterococci harbouring oxazolidinone resistance genes among healthy humans in Switzerland and to genetically characterize the isolates. Methods: A total of 399 stool samples from healthy individuals employed in different food-processing plants were cultured on a selective medium containing 10 mg/L florfenicol. Resulting enterococci were screened by PCR for the presence of cfr, optrA and poxtA. A hybrid approach combining short-read and long-read WGS was used to analyse the genetic context of the cfr, optrA and poxtA genes. Results: Enterococcus faecalis (n = 6), Enterococcus faecium (n = 6), Enterococcus gallinarum (n = 1) and Enterococcus hirae (n = 2) were detected in 15/399 (3.8%) of the faecal samples. They carried cfr + poxtA, optrA, optrA + poxtA or poxtA. Four E. faecalis harbouring optrA and one E. faecium carrying poxtA were resistant to linezolid (8 mg/L). In most optrA-positive isolates, the genetic environments of optrA were highly variable, but often resembled previously described platforms. In most poxtA-positive isolates, the poxtA gene was flanked on both sides by IS1216E elements and located on medium-sized plasmids. Conclusions: Faecal carriage of Enterococcus spp. harbouring cfr, optrA and poxtA in healthy humans associated with the food-production industry demonstrates the possibility of spread of oxazolidinone resistance genes into the community. Given the importance of linezolid as a last-resort antibiotic for the treatment of serious infections caused by Gram-positive pathogens, the detection of the oxazolidinone resistance determinants in enterococci from healthy humans is of concern for public health

Whole genome sequence-based characterisation of Shiga toxin-producing Escherichia coli isolated from game meat originating from several European countries

Game meat is becoming increasingly popular but may be contaminated with pathogenic bacteria such as Shiga toxin-producingEscherichia coli(STEC). STEC cause gastrointestinal illnesses including diarrhoea, haemorrhagic colitis (HC), and the haemolytic uremic syndrome (HUS). The aim of this study was to assess the occurrence of STEC in 92 meat samples from chamois (n = 2), red deer (n = 27), roe deer (n = 38), and wild boar (n = 25), from Switzerland and other European countries. After enrichment, Shiga-toxin encoding genes (stx) were detected by PCR in 78 (84%) of the samples and STEC were isolated from 23 (25%) of the same samples. Nine different serotypes and eight different sequence types (STs) were found, with O146:H28 ST738 (n = 10) and O110:H31 ST812 (n = 5) predominating. None of the STEC belonged to the so-called top-five serogroups O26, O103, O111, O145, and O157. Subtyping ofstxidentifiedstx1c(n = 9),stx2a(n = 1),stx2b(n = 19),stx2e(n = 2), andstx2g(n = 1). Additional virulence factors (VFs) comprisedehx(n = 12),iha(n = 21),sta1(n = 1), andsubAB(n = 19). None of the isolates contained theeaegene. Twenty-one STEC contained VFs associated with extra-intestinal pathogenicE. coli(ExPEC). Overall, the pathogenic potential of STEC in game meat is moderate, though the isolation of one STEC strain carryingstx2a, and of STEC/ExPEC hybrids suggests a role of game meat as a potential source of STEC infections in humans. Therefore, detailed knowledge of the safe handling and preparation of game meat is needed to prevent foodborne infections

High occurrence of Enterococcus faecalis, Enterococcus faecium, and Vagococcus lutrae harbouring oxazolidinone resistance genes in raw meat-based diets for companion animals – a public health issue, Switzerland, September 2018 to May 2020

Introduction: Enterococci harbouring genes encoding resistance to florfenicol and the oxazolidinone antimicrobial linezolid have emerged among food-producing animals and meat thereof, but few studies have analysed their occurrence in raw meat-based diets (RMBDs) for pets.AimWe aimed to examine how far RMBDs may represent a source of bacteria with oxazolidinone resistance genes. Methods: Fifty-nine samples of different types of RMBDs from 10 suppliers (three based in Germany, seven in Switzerland) were screened for florfenicol-resistant Gram-positive bacteria using a selective culture medium. Isolates were phenotypically and genotypically characterised.ResultsA total of 27 Enterococcus faecalis, Enterococcus faecium, and Vagococcus lutrae isolates were obtained from 24 of the 59 samples. The optrA, poxtA, and cfr genes were identified in 24/27, 6/27 and 5/27 isolates, respectively. Chloramphenicol and linezolid minimum inhibitory concentrations (MICs) ranged from 24.0 mg/L-256.0 mg/L, and 1.5 mg/L-8.0 mg/L, respectively. According to the Clinical and Laboratory Standards Institute (CLSI) breakpoints, 26 of 27 isolates were resistant to chloramphenicol (MICs ≥ 32 mg/L), and two were resistant to linezolid (MICs ≥ 8 mg/L). Multilocus sequence typing analysis of the 17 E. faecalis isolates identified 10 different sequence types (ST)s, with ST593 (n = 4 isolates) and ST207 (n = 2 isolates) occurring more than once, and two novel STs (n = 2 isolates). E. faecium isolates belonged to four different STs (168, 264, 822, and 1846). Conclusion: The high occurrence in our sample of Gram-positive bacteria harbouring genes encoding resistance to the critical antimicrobial linezolid is of concern since such bacteria may spread from companion animals to humans upon close contact between pets and their owners

Environmental dissemination of carbapenemase-producing Enterobacteriaceae in rivers in Switzerland

The aquatic environment takes on a key role in the dissemination of antimicrobial-resistant Enterobacteriaceae. This study assesses the occurrence of carbapenemase-producing Enterobacteriaceae (CPE) in freshwater samples from rivers, inland canals, and streams throughout Switzerland, and characterizes the isolated strains using phenotypic and NGS-based genotypic methods. CPE producing KPC-2 (n = 2), KPC-3 (n = 1), NDM-5 (n = 3), OXA-48 (n = 3), OXA-181 (n = 6), and VIM-1 (n = 2) were detected in 17/164 of the water samples. Seven Escherichia coli had sequence types (STs) that belonged to extra-intestinal pathogenic clonal lineages ST38, ST73, ST167, ST410, and ST648. The majority (16/17) of the carbapenemase genes were located on plasmids, including the widespread IncC (n = 1), IncFIIA (n = 1), and IncFIIB plasmids (n = 4), the epidemic IncL (n = 1) and IncX3 (n = 5) plasmids, a rare Col156 plasmid (n = 1), and the mosaic IncFIB, IncR, and IncQ plasmids (n = 3). Plasmids were composed of elements that were identical to those of resistance plasmids retrieved from clinical and veterinary isolates locally and worldwide. Our data show environmental dissemination of high-risk CPE clones in Switzerland. Epidemic and mosaic-like plasmids carrying clinically relevant carbapenemase genes are replicating and evolving pollutants of river ecosystems, representing a threat to public health and environmental integrity

Listeriosis Caused by Persistence of Listeria monocytogenes Serotype 4b Sequence Type 6 in Cheese Production Environment

A nationwide outbreak of human listeriosis in Switzerland was traced to persisting environmental contamination of a cheese dairy with Listeria monocytogenes serotype 4b, sequence type 6, cluster type 7488. Whole-genome sequencing was used to match clinical isolates to a cheese sample and to samples from numerous sites within the production environment. Listeriosis is a potentially lethal infection, and the elderly population, pregnant women, and immunocompromised persons at particular risk (1). Foods, in particular ready-to-eat foodstuffs, including meat, fish, dairy products, fruits, and vegetables, represent the major vehicle for sporadic cases and outbreaks of listeriosis (2). Listeria monocytogenes serotype 4b sequence type 6 (ST6) has emerged since 1990 as a hypervirulent clone that is associated with particularly worse outcome for case-patients who have Listeria meningitis and therefore poses a particular threat to consumer health (3,4). L. monocytogenes ST6 is increasingly associated with outbreaks, including an outbreak linked to frozen vegetables in 5 countries in Europe during 2015–2018 (5), an outbreak associated with contaminated meat pâté in Switzerland during 2016 (6), and the largest listeriosis outbreak globally, which occurred in South Africa during 2017–2018 (7,8). More recently, the largest outbreak of listeriosis in Europe in the past 25 years was reported in Germany and was traced back to blood sausages contaminated with L. monocytogenes ST6 belonging to a particular clone referred to as Epsilon1a (9). Human listeriosis is a reportable disease in Switzerland. All cases of culture- or PCR-confirmed human listeriosis are reported to the Swiss Federal Office of Public Health (SFOPH). Diagnostic laboratories and regional (cantonal) laboratories forward isolates to the Swiss National Reference Centre for Enteropathogenic Bacteria and Listeria for strain characterization, ensuring early recognition of Listeria clusters among food isolates or human cases. We report an outbreak of listeriosis associated with cheese contaminated with L. monocytogenes 4b ST6 in Switzerland

Inertial Sensor-Based Gait and Attractor Analysis as Clinical Measurement Tool: Functionality and Sensitivity in Healthy Subjects and Patients With Symptomatic Lumbar Spinal Stenosis

Objective: To determine if the attractor for acceleration gait data is similar among healthy persons defining a reference attractor; if exercise-induced changes in the attractor in patients with symptomatic lumbar spinal stenosis (sLSS) are greater than in healthy persons; and if the exercise-induced changes in the attractor are affected by surgical treatment.Methods: Twenty-four healthy subjects and 19 patients with sLSS completed a 6-min walk test (6MWT) on a 30-m walkway. Gait data were collected using inertial sensors (RehaGait®;) capturing 3-dimensional foot accelerations. Attractor analysis was used to quantify changes in low-pass filtered acceleration pattern (δM) and variability (δD) and their combination as attractor-based index (δF = δM* δD) between the first and last 30 m of walking. These parameters were compared within healthy persons and patients with sLSS (preoperatively and 10 weeks and 12 months postoperatively) and between healthy persons and patients with sLSS. The variability in the attractor pattern among healthy persons was assessed as the standard deviation of the individual attractors.Results: The attractor pattern differed greatly among healthy persons. The variability in the attractor between subjects was about three times higher than the variability around the attractor within subject. The change in gait pattern and variability during the 6MWT did not differ significantly in patients with sLSS between baseline and follow-up but differed significantly compared to healthy persons.Discussion: The attractor for acceleration data varied largely among healthy subjects, and hence a reference attractor could not be generated. Moreover, the change in the attractor and its variability during the 6MWT differed between patients and elderly healthy persons but not between repeated assessments. Hence, the attractor based on low-pass filtered signals as used in this study may reflect pathology specific differences in gait characteristics but does not appear to be sufficiently sensitive to serve as outcome parameter of decompression surgery in patients with sLSS

Cartilaginous endplates: A comprehensive review on a neglected structure in intervertebral disc research

The cartilaginous endplates (CEP) are key components of the intervertebral disc (IVD) necessary for sustaining the nutrition of the disc while distributing mechanical loads and preventing the disc from bulging into the adjacent vertebral body. The size, shape, and composition of the CEP are essential in maintaining its function, and degeneration of the CEP is considered a contributor to early IVD degeneration. In addition, the CEP is implicated in Modic changes, which are often associated with low back pain. This review aims to tackle the current knowledge of the CEP regarding its structure, composition, permeability, and mechanical role in a healthy disc, how they change with degeneration, and how they connect to IVD degeneration and low back pain. Additionally, the authors suggest a standardized naming convention regarding the CEP and bony endplate and suggest avoiding the term vertebral endplate. Currently, there is limited data on the CEP itself as reported data is often a combination of CEP and bony endplate, or the CEP is considered as articular cartilage. However, it is clear the CEP is a unique tissue type that differs from articular cartilage, bony endplate, and other IVD tissues. Thus, future research should investigate the CEP separately to fully understand its role in healthy and degenerated IVDs. Further, most IVD regeneration therapies in development failed to address, or even considered the CEP, despite its key role in nutrition and mechanical stability within the IVD. Thus, the CEP should be considered and potentially targeted for future sustainable treatments

Immuno-modulatory effects of intervertebral disc cells

Low back pain is a highly prevalent, chronic, and costly medical condition predominantly triggered by intervertebral disc degeneration (IDD). IDD is often caused by structural and biochemical changes in intervertebral discs (IVD) that prompt a pathologic shift from an anabolic to catabolic state, affecting extracellular matrix (ECM) production, enzyme generation, cytokine and chemokine production, neurotrophic and angiogenic factor production. The IVD is an immune-privileged organ. However, during degeneration immune cells and inflammatory factors can infiltrate through defects in the cartilage endplate and annulus fibrosus fissures, further accelerating the catabolic environment. Remarkably, though, catabolic ECM disruption also occurs in the absence of immune cell infiltration, largely due to native disc cell production of catabolic enzymes and cytokines. An unbalanced metabolism could be induced by many different factors, including a harsh microenvironment, biomechanical cues, genetics, and infection. The complex, multifactorial nature of IDD brings the challenge of identifying key factors which initiate the degenerative cascade, eventually leading to back pain. These factors are often investigated through methods including animal models, 3D cell culture, bioreactors, and computational models. However, the crosstalk between the IVD, immune system, and shifted metabolism is frequently misconstrued, often with the assumption that the presence of cytokines and chemokines is synonymous to inflammation or an immune response, which is not true for the intact disc. Therefore, this review will tackle immunomodulatory and IVD cell roles in IDD, clarifying the differences between cellular involvements and implications for therapeutic development and assessing models used to explore inflammatory or catabolic IVD environments

Distribution of virulence factors in ESBL-producing Escherichia coli isolated from the environment, livestock, food and humans

In this study, extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli isolates recovered from the following sources were characterized with regard to the occurrence and distribution of uropathogenic and enteric pathogenic virulence factors: surface waters (rivers and lakes, n=60), the intestines of freshwater fish (n=33), fresh vegetables (n=26), retail poultry meat (n=13) and the fecal samples of livestock (n=28), healthy humans (n=34) and primary care patients (n=13). Among the 207 isolates, 82% tested positive by PCR for one or more of the virulence factors (VF) that predict uropathogenicity, TraT, fyuA, chuA, PAI, yfcv or vat. Uropathogenic E. coli (UPEC) were detected in each of the analyzed sources. Regarding virulence factors for intestinal pathogenic E. coli, these were found more rarely and predominantly associated with the aquatic environment, with aagR (EAEC) found in isolates from surface waters and STp (porcine heat stable enterotoxin) and LT (heat-labile enterotoxin) associated with isolates from fish. Aggregate VF scores (the number of unique virulence factors detected for each isolate) were lowest among isolates belonging to phylogenetic group B1 and highest among group B2. Clustering of the isolates by phylogenetic group, multilocus sequence type (MLST) and ESBL-types revealed clonal overlaps of A:ST10(CTX-M-1) and D:ST350(CTX-M-1) between the sources of livestock, poultry meat and healthy humans, suggesting livestock, in particular poultry, represents a potential reservoir for these particular UPEC clones. The clones A:ST10(CTX-M-55) and B2:ST131(CTX-M-27), harboring uropathogenic virulence factors were significantly associated with fresh vegetables and with fish, respectively. Further clonal complexes with source overlaps included D:ST38(CTX-M-14), D:ST69(CTX-M-15), D:ST405(CTX-M-15) and D:ST648(CTX-M-15), which were found in surface water and healthy humans. Identifying potential reservoirs of UPEC in the environment, animals, food and humans is important in order to assess routes of transmission and risk factors for acquiring UPE