Antimicrobial resistance patterns and genotypes of Salmonella enterica serovar Hadar strains associated with human infections in Switzerland, 2005-2010

Salmonella Hadar ranks in the top ten serovars reported from humans in Switzerland. In this study, all 64 S. Hadar strains isolated from different patients from 2005 to 2010 in Switzerland were characterized by (i) assessing phenotypic antimicrobial resistance profiles using the disk diffusion method and (ii) by genotyping using pulsed-field gel electrophoresis (PFGE) in order to evaluate the relationship of the strains. The annual incidences varied between 0·32/100000 in 2005 (highest incidence) and 0·065/100000 in 2007 (lowest incidence). In total 71·8% of the isolates were resistant to nalidixic acid. Although 40·6% of the strains were resistant to the β-lactam antibiotic ampicillin, they remained susceptible to the third-generation cephalosporin cefotaxime. Genotyping revealed a primary cluster consisting of 42 strains, sharing a similarity of >92%, with a subcluster of 18 strains with indistinguishable patterns. Resistance profiles allowed further differentiation within this subcluster providing a link of two strains to an outbreak in Spai

Human infections with Shiga toxin-producing Escherichia coli, Switzerland, 2010-2014

Objectives: The aim of this study was to characterize a collection of 95 Shigatoxin-producing E.coli (STEC) isolated from human patients in Switzerland during 2010-2014. Methods: We performed O and H serotyping and molecular subtyping. Results: The five most common serogroups were O157, O145, O26, O103, and O146. Of the 95 strains, 35 (36.8%) carried stx1 genes only, 43 strains (45.2%) carried stx2 and 17 (17.9%) harbored combinations of stx1 and stx2 genes. Stx1a (42 strains) and stx2a (32 strains) were the most frequently detected stx subtypes. Genes for intimin (eae), hemolysin (hly), iron-regulated adhesion (iha), and the subtilase cytotoxin subtypes subAB1, subAB2-1, subAB2-2, or subAB2-3 were detected in 70.5, 83.2, 74.7, and 20% of the strains, respectively. Multilocus sequence typing assigned the majority (58.9%) of the isolates to five different clonal complexes (CC), 11, 32, 29, 20, and 165, respectively. CC11 included all O157:[H7] and O55:[H7] isolates. CC32 comprised O145:[H28] isolates, and O145:[H25] belonged to sequence type (ST) 342. CC29 contained isolates of the O26:[H11], O111:[H8] and O118:[Hnt] serogroups, and CC20 encompassed isolates of O51:H49/[Hnt] and O103:[H2]. CC165 included isolates typed O80:[H2]-ST301, all harboring stx2d, eae-ξ, hly, and 66.7% additionally harboring iha. All O80:[H2]-ST301 strains harbored at least 7 genes carried by pS88, a plasmid associated with extraintestinal virulence. Compared to data from Switzerland from the years 2000-2009, an increase of the proportion of non-O157 STEC infections was observed as well as an increase of infections due to STEC O146. By contrast, the prevalence of the highly virulent German clone STEC O26:[H11]-ST29 decreased from 11.3% during 2000-2009 to 1.1% for the time span 2010-2014. The detection of O80:[H2]-ST301 harboring stx2d, eae-ξ, hly, iha, and pS88 related genes suggests an ongoing emergence in Switzerland of an unusual, highly pathogenic STEC serotype. Conclusions: Serotyping and molecular subtyping of clinical STEC demonstrate that although STEC O157 predominates among STEC isolated from diseased humans, non-O157 STEC infections are increasing in Switzerland, including those due to STEC O146:[H2/H21/H28]-ST442/ST738 harboring subAB variants, and the recently emerged STEC O80:[H2]-ST301 harboring eae-ξ and pS88 associated extraintestinal pathogenic virulence genes

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

Antimicrobial resistance profiles of <i>Escherichia coli</i> and prevalence of extended‐spectrum beta‐lactamase‐producing Enterobacteriaceae in calves from organic and conventional dairy farms in Switzerland

This study compared the antimicrobial resistance (AMR) among commensal Escherichia coli in the fecal microbiota of young calves raised on organic and on conventional dairy farms in Switzerland. Further, fecal carriage of extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae was assessed for calves from both farming systems. Where possible, data on antimicrobial usage (AMU) were obtained. Antimicrobial susceptibility testing was performed on a total of 71 isolates using the disk diffusion method. ESBL producers were characterized by polymerase chain reaction-based multilocus sequence typing and sequencing of the blaESBL genes. Organically raised calves were significantly more likely to harbor E. coli that showed AMR to ampicillin (odds ratio [OR]: 2.78, 95% confidence interval [CI]: 1.02-7.61, p = 0.046), streptomycin (OR: 3.22, 95% CI: 1.17-8.92, p = 0.046), kanamycin (OR: 11.3, 95% CI: 2.94-43.50, p < 0.001), and tetracycline (OR: 3.25, 95% CI: 1.13-9.31, p = 0.028). Calves with reported AMU were significantly more likely to harbor E. coli with resistance to ampicillin (OR: 3.91, 95% CI: 1.03-14.85, p = 0.045), streptomycin (OR: 4.35, 95% CI: 1.13-16.7, p = 0.045), and kanamycin (OR: 8.69, 95% CI: 2.01-37.7, p = 0.004). ESBL-producing Enterobacteriaceae (18 E. coli and 3 Citrobacter braakii) were detected exclusively among samples from conventionally farmed calves (OR: infinity [∞], 95% CI: 2.3-∞, p < 0.0013). The observations from this study suggest that AMR is highly prevalent among commensal E. coli in young dairy calves, irrespective of the farm management system, with proportions of certain resistance phenotypes higher among organic calves. By contrast, the occurrence of ESBL producers among young dairy calves may be linked to factors associated with conventional farming

Seroprevalence of Toxoplasma gondii and Salmonella in Hunted Wild Boars from Two Different Regions in Switzerland

Toxoplasma gondii and Salmonella are zoonotic foodborne pathogens that may be transmitted to humans through the consumption of raw or undercooked meat, including game. The aim of this study was to determine the seroprevalence of T. gondii and Salmonella antibodies in wild boars in two different regions in Switzerland. During the hunting season of 2020, a total of 126 diaphragm muscle samples of hunted wild boars were collected and the meat juice of these samples was analysed for pathogen-specific IgG antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. The overall seroprevalences were 35% for T. gondii and 17% for Salmonella, respectively. In general, seropositivity increased with the age of the animals. Seroprevalences of T. gondii were similar for animals from the northern region (29%) to those from the southern region (36.8%), indicating that T. gondii is widespread in the sylvestrian environment. By contrast, Salmonella seropositivity was remarkably higher in wild boars from the north (52%) compared with those from the south (5.3%). The high occurrence of Salmonella may represent a risk of transmission to compatriot domestic animals such free-range farmed pigs as well as to humans. Further, meat of hunted wild boars may present a source of human toxoplasmosis or salmonellosis

Cardio- and reno-protective effect of remote ischemic preconditioning in patients undergoing percutaneous coronary intervention. A prospective, non-randomized controlled trial

AbstractObjectivesThis study assessed the cardio- and renoprotective effect of remote ischemic Preconditioning (PreC) in patients undergoing percutaneous coronary intervention (PCI).BackgroundMyocyte necrosis and contrast induced nephropathy (CIN) occur frequently in PCI and are associated with subsequent cardiovascular events. Methods: Two hundred consecutive patients undergoing elective PCI with normal baseline troponin-I (cTnI) values were recruited. Subjects were systematically allocated into 2 groups: 100 patients received PreC (created by three 5min inflations of a blood pressure cuff to 200mmHg around the upper arm, separated by 5min intervals of reperfusion) <2h before the PCI procedure, and control group (n=100).ResultsThe incidence of PCI-related myocardial infarction (MI 4a) at 24h after PCI was lower in the PreC group compared with control group (41% vs 64%, P=0.02). Subjects who received PreC had significant trend toward lower incidence of CIN at 72h after contrast exposure (4 vs. 11, P=0.05) and less chest pain during stent implantation compared to control group. At 3 months, the major adverse event rate was lower in the PreC group (6 vs. 14 events; P=0.04).ConclusionsThe use of PreC<2h before PCI, reduces the incidence of PCI-related MI 4a, tends to decrease the incidence of CIN and improves ischemic symptoms in patients undergoing elective PCI. The observed cardio- and renoprotection appears to confer sustained benefit on reduced major adverse events at 3 month follow-up beyond what is seen with judicious pre- and post-hydration (ClinicalTrials.gov identifier: NCT02313441)

Epidemiological links and antimicrobial resistance of clinical Salmonella enterica ST198 isolates: a nationwide microbial population genomic study in Switzerland

Salmonella is a leading cause of foodborne outbreaks and systemic infections worldwide. Emerging multi-drug resistant Salmonella lineages such as a ciprofloxacin-resistant subclade (CIPR) within Salmonella enterica serovar Kentucky ST198 threaten the effective prevention and treatment of infections. To understand the genomic diversity and antimicrobial resistance gene content associated with S. Kentucky in Switzerland, we whole-genome sequenced 70 human clinical isolates obtained between 2010 and 2020. Most isolates belonged to ST198-CIPR. High- and low-level ciprofloxacin resistance among CIPR isolates was associated with variable mutations in ramR and acrB in combination with stable mutations in quinolone-resistance determining regions (QRDRs). Analysis of isolates from patients with prolonged ST198 colonization indicated subclonal adaptions with the ramR locus as a mutational hotspot. SNP analyses identified multiple clusters of near-identical isolates, which were often associated with travel but included spatiotemporally linked isolates from Switzerland. The largest SNP cluster was associated with travellers returning from Indonesia, and investigation of global data linked >60 additional ST198 salmonellosis isolates to this cluster. Our results emphasize the urgent need for implementing whole-genome sequencing as a routine tool for Salmonella surveillance and outbreak detection