Panton-Valentine Leukocidin-Positive Staphylococcus aureus in Family and Pet Cat.

Continued detection of Panton-Valentine leukocidin-positive Staphylococcus aureus in samples from a family with severe repeated skin infections and their pet cat suggests transmission between the family and the cat. Decolonizing the pet led to successful elimination of the bacteria from the household. Clinicians should consider pet cats as possible reinfection sources.

Pilot study on nasal microbiota dynamics and MRSA carriage of a pig cohort housed on straw bedding.

Methicillin-resistant Staphylococcus aureus (MRSA) can be transmitted between pigs and humans on farms. Hence, the reduction of MRSA carriage in pigs could decrease the risk of zoonotic transmission. Recently, straw bedding has been found to significantly reduce MRSA carriage in pigs. The mechanisms behind this effect remain unclear but changes in the nasal microbiome may play a role. In this exploratory study, the nasal microbiota of pigs kept on straw was examined using V1/V2 16S rRNA gene sequencing. Nasal swabs were collected from 13 pigs at six different time points during the course of a full fattening cycle resulting in 74 porcine samples. In addition, straw samples were collected at each time point. Eleven out of 13 pigs were MRSA positive at housing-in. We found a strong temporal pattern in the microbial communities. Both microbial diversity and abundance of Staphylococcus species peaked in week 5 after introduction to the straw stable decreased in week 10, when all pigs turned MRSA-negative, and increased again toward the end of the fattening period. These findings show that the introduction of pigs into a new environment has a huge impact on their nasal microbiota, which might lead to unfavorable conditions for MRSA. Moreover, other Staphylococcus species may play a role in eliminating MRSA carriage. We designed a follow-up study including two different husbandry systems to further assess these effects.

[Therapy-relevant antibiotic resistances in a One Health context]. / Therapierelevante Antibiotikaresistenzen im One-Health-Kontext.

One Health refers to a concept that links human, animal, and environmental health. In Germany, there is extensive data on antibiotic resistance (AMR) and multidrug-resistant (micro)organisms (MDRO) in human and veterinary medicine, as well as from studies in various environmental compartments (soil, water, wastewater). All these activities are conducted according to different specifications and standards, which makes it difficult to compare data. A focus on AMR and MDRO of human therapeutic importance is helpful to provide some guidance. Most data are available across sectors on methicillin-resistant Staphylococcus aureus (MRSA) and multiresistant Enterobacterales such as Escherichia coli and Klebsiella pneumoniae. Here, the trends of resistance are heterogeneous. Antibiotic use leads to MRE selection, which is well documented. Success in minimizing antibiotic use has also been demonstrated in recent years in several sectors and could be correlated with success in containing AMR and MDRO (e.g., decrease in MRSA in human medicine). Sector-specific measures to reduce the burden of MDRO and AMR are also necessary, as not all resistance problems are linked to other sectors. Carbapenem resistance is still rare, but most apparent in human pathogens. Colistin resistance occurs in different sectors but shows different mechanisms in each. Resistance to antibiotics of last resort such as linezolid is rare in Germany, but shows a specific One Health correlation. Efforts to harmonize methods, for example in the field of antimicrobial susceptibility testing and genome-based pathogen and AMR surveillance, are an important first step towards a better comparability of the different data collections.

A prospective multicentre screening study on multidrug-resistant organisms in intensive care units in the Dutch-German cross-border region, 2017 to 2018: the importance of healthcare structures.

BackgroundAntimicrobial resistance poses a risk for healthcare, both in the community and hospitals. The spread of multidrug-resistant organisms (MDROs) occurs mostly on a local and regional level, following movement of patients, but also occurs across national borders.AimThe aim of this observational study was to determine the prevalence of MDROs in a European cross-border region to understand differences and improve infection prevention based on real-time routine data and workflows.MethodsBetween September 2017 and June 2018, 23 hospitals in the Dutch (NL)-German (DE) cross-border region (BR) participated in the study. During 8 consecutive weeks, patients were screened upon admission to intensive care units (ICUs) for nasal carriage of meticillin-resistant Staphylococcus aureus (MRSA) and rectal carriage of vancomycin-resistant Enterococcus faecium/E. faecalis (VRE), third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE) and carbapenem-resistant Enterobacteriaceae (CRE). All samples were processed in the associated laboratories.ResultsA total of 3,365 patients were screened (median age: 68 years (IQR: 57-77); male/female ratio: 59.7/40.3; NL-BR: n = 1,202; DE-BR: n = 2,163). Median screening compliance was 60.4% (NL-BR: 56.9%; DE-BR: 62.9%). MDRO prevalence was higher in DE-BR than in NL-BR, namely 1.7% vs 0.6% for MRSA (p = 0.006), 2.7% vs 0.1% for VRE (p < 0.001) and 6.6% vs 3.6% for 3GCRE (p < 0.001), whereas CRE prevalence was comparable (0.2% in DE-BR vs 0.0% in NL-BR ICUs).ConclusionsThis first prospective multicentre screening study in a European cross-border region shows high heterogenicity in MDRO carriage prevalence in NL-BR and DE-BR ICUs. This indicates that the prevalence is probably influenced by the different healthcare structures.

[Generation of an FAQ page on Dealing with Multi-resistant Pathogens at the Interface of Veterinary and Human Medicine]. / Konzeption von Frequently Asked Questions zum Umgang mit multiresistenten Erregern an der Schnittstelle von Veterinär- und Humanmedizin.

OBJECTIVE: The aims of this work were the systematic and evidence-based generation and answering of frequently asked questions (FAQ) regarding contact with multi-drug resistant pathogens (MDR) including aspects of veterinary and human medicine for the public health service (PHS) and the general population. METHODS: In order to determine the information needs of the population, guideline-based expert interviews with veterinarians and physicians were conducted in five surveys. In addition, information about the project was published in two journals and the participants were asked to submit open questions from their daily routine with respect to MDR. The results of the interviews and project calls were divided into categories, and frequently mentioned topics were prepared as FAQ. For answering the FAQ, a systematic literature search in the databases Pubmed and Wiley Online Library was conducted. A panel of experts subsequently evaluated the FAQ drafts, and a consensus was reached in case of conflicting results. Thereafter, the FAQs were evaluated by physicians and veterinarians of the PHS. RESULTS: Nine FAQs were generated in total. In addition to a survey of the current state of research, recommendations were made for private dealing with non-medical contact with MDR at the interface of human and veterinary medicine. The recommendations depended on the respective setting and the type of animal contact. Different recommendations were given for the handling of MDR in pets, farm animals, animals in communal facilities and animals used for animal-assisted therapies. The most important measure against the spread of MDR between humans and animals proved to be regular and careful handwashing. CONCLUSION: Mixed methods were used to ensure the quality of the FAQ. Limitations were found in the literature search. Not all submitted questions could be answered with the available literature. In the future, the FAQ should be continuously updated and extended.

A comparison of two multiplex-PCR assays for the diagnosis of traveller's diarrhoea.

BACKGROUND: Numerous multiplex-PCR assays are now available in routine diagnostics but their clinical value is controversial if a clear association between clinical symptoms and the detection of a particular pathogen is missing. The objective of this work was to evaluate a multiplex-PCR assay for the diagnosis of traveller's diarrhoea (TD) in a case-control study and to assess the concordance with the BioFire® FilmArray® Gastrointestinal Panel. METHODS: Stool samples from cases (n = 61) and controls (n = 30) were collected during travel and analysed by the GI-EB Screening assay (Seegene) in a case-control study. The concordance with the BioFire® FilmArray® Gastrointestinal Panel was expressed as the proportion of participants in which both tests agreed in the category "detected" and "not detected". RESULTS: None of the test-target organisms (Campylobacter spp., Clostridioides difficile toxin A/B, Salmonella spp., Shigella spp./enteroinvasive Escherichia coli, E. coli O157, Shiga toxin-producing E. coli, Yersinia enterocolitica) was significantly associated with TD GI-EB Screening assay. The GI-EB Screening assay had an agreement with the BioFire® FilmArray® of 86.8-100%. CONCLUSION: The selection of test-target organisms included in the GI-EB Screening assay appears inappropriate for the diagnostic work-up of TD as none of the detected pathogens was associated with TD. The GI-EB Screening assay had a good concordance with BioFire® FilmArray®.

Changing epidemiology of meticillin-resistant Staphylococcus aureus in 42 hospitals in the Dutch-German border region, 2012 to 2016: results of the search-and-follow-policy.

IntroductionMeticillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections.AimWe describe MRSA colonisation/infection and bacteraemia rate trends in Dutch-German border region hospitals (NL-DE-BRH) in 2012-16.MethodsAll 42 NL-DE BRH (8 NL-BRH, 34 DE-BRH) within the cross-border network EurSafety Health-net provided surveillance data (on average ca 620,000 annual hospital admissions, of these 68.0% in Germany). Guidelines defining risk for MRSA colonisation/infection were reviewed. MRSA-related parameters and healthcare utilisation indicators were derived. Medians over the study period were compared between NL- and DE-BRH.ResultsMeasures for MRSA cases were similar in both countries, however defining patients at risk for MRSA differed. The rate of nasopharyngeal MRSA screening swabs was 14 times higher in DE-BRH than in NL-BRH (42.3 vs 3.0/100 inpatients; p < 0.0001). The MRSA incidence was over seven times higher in DE-BRH than in NL-BRH (1.04 vs 0.14/100 inpatients; p < 0.0001). The nosocomial MRSA incidence-density was higher in DE-BRH than in NL-BRH (0.09 vs 0.03/1,000 patient days; p = 0.0002) and decreased significantly in DE-BRH (p = 0.0184) during the study. The rate of MRSA isolates from blood per 100,000 patient days was almost six times higher in DE-BRH than in NL-BRH (1.55 vs 0.26; p = 0.0041). The patients had longer hospital stays in DE-BRH than in NL-BRH (6.8 vs 4.9; p < 0.0001). DE-BRH catchment area inhabitants appeared to be more frequently hospitalised than their Dutch counterparts.ConclusionsOngoing IPC efforts allowed MRSA reduction in DE-BRH. Besides IPC, other local factors, including healthcare systems, could influence MRSA epidemiology.

Prevalence and Genomic Structure of Bacteriophage phi3 in Human-Derived Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates from 2000 to 2015.

Whereas the emergence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) clonal complex 398 (CC398) in animal husbandry and its transmission to humans are well documented, less is known about factors driving the epidemic spread of this zoonotic lineage within the human population. One factor could be the bacteriophage phi3, which is rarely detected in S. aureus isolates from animals but commonly found among isolates from humans, including those of the human-adapted methicillin-susceptible S. aureus (MSSA) CC398 clade. The proportion of phi3-carrying MRSA spa-CC011 isolates, which constitute presumptively LA-MRSA within the multilocus sequence type (MLST) clonal complex 398, was systematically assessed for a period of 16 years to investigate the role of phi3 in the adaptation process of LA-MRSA to the human host. For this purpose, 632 MRSA spa-CC011 isolates from patients of a university hospital located in a pig farming-dense area in Germany were analyzed. Livestock-associated acquisition of MRSA spa-CC011 was previously reported as having increased from 1.8% in 2000 to 29.4% in 2014 in MRSA-positive patients admitted to this hospital. However, in this study, the proportion of phi3-carrying isolates rose only from 1.1% (2000 to 2006) to 3.9% (2007 to 2015). Characterization of the phi3 genomes revealed 12 different phage types ranging in size from 40,712 kb up to 44,003 kb, with four hitherto unknown integration sites (genes or intergenic regions) and several modified bacterial attachment (attB) sites. In contrast to the MSSA CC398 clade, phi3 acquisition seems to be no major driver for the readaptation of MRSA spa-CC011 to the human host.

Staphylococcus aureus from the German general population is highly diverse.

OBJECTIVES: This prospective cohort study evaluates colonization dynamics and molecular characteristics of methicillin-susceptible and - resistant Staphylococcus aureus (MSSA/MRSA) in a German general population. METHODS: Nasal swabs of 1878 non-hospitalized adults were screened for S. aureus. Participants were screened thrice in intervals of 6-8 months. Isolates were characterized by spa and agr typing, mecA and mecC possession, respectively, and PCRs targeting virulence factors. RESULTS: 40.9% of all participants carried S. aureus at least once while 0.7% of the participants carried MRSA (mainly spa t011). MSSA isolates (n=1359) were associated with 331 different spa types; t084 (7.7%), t091 (6.1%) and t012 (71, 5.2%) were predominant. Of 206 participants carrying S. aureus at all three sampling time points, 14.1% carried the same spa type continuously; 5.3% carried different spa types with similar repeat patterns, but 80.6% carried S. aureus with unrelated spa types. MSSA isolates frequently harboured genes encoding enterotoxins (sec: 16.6%, seg: 63.1%, sei: 64.5%) and toxic shock syndrome toxin (tst: 17.5%), but rarely Panton-Valentine leukocidin (lukS-PV/lukF-PV: 0.2%). CONCLUSIONS: MSSA colonizing human nares in the community are clonally highly diverse. Among those constantly carrying S. aureus, clonal lineages changed over time. The proportion of persistent S. aureus carriers was lower than reported elsewhere.

Whole-Genome Sequencing Elucidates Epidemiology of Nosocomial Clusters of Acinetobacter baumannii.

We characterized two epidemiologically similar Acinetobacter baumannii clusters from two separate intensive care units (ICU) using core genome multilocus sequence typing. Clonal spread was confirmed in ICU-1 (12 of 14 isolates shared genotypes); in ICU-2, all genotypes (13 isolates) were diverse, thus excluding transmissions and enabling adequate infection control measures.

Detection of mecA- and mecC-Positive Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates by the New Xpert MRSA Gen 3 PCR Assay.

An advanced methicillin-resistant Staphylococcus aureus (MRSA) detection PCR approach targeting SCCmec-orfX along with mecA and mecC was evaluated for S. aureus and coagulase-negative staphylococci. The possession of mecA and/or mecC was correctly confirmed in all cases. All methicillin-susceptible S. aureus strains (n = 98; including staphylococcal cassette chromosome mec element [SCCmec] remnants) and 98.1% of the MRSA strains (n = 160, including 10 mecC-positive MRSA) were accurately categorized.

A geospatial analysis of flies and the spread of antimicrobial resistant bacteria.

Livestock is often colonized with ESBL-producing Enterobacteriaceae (ESBL-E) and Staphylococcus aureus. There is a risk that flies spread antimicrobial resistant bacteria from livestock to humans. Here, we screened flies from urban and rural areas near the city of Münster, Germany, for the presence of ESBL-E and S. aureus and compared molecular characteristics of these isolates with those isolated from humans in the same region. In total, 1346 single flies were grinded and cultured overnight in BHI-broth. The broth was cultured on Columbia blood agar and selective media for the detection of S. aureus and ESBL-E. Human isolates from routine diagnostics at the University Hospital Münster were used for comparison. Antimicrobial susceptibility, phylogroups (Escherichia coli), spa types/multilocus sequence types (S. aureus) and selected antimicrobial resistance genes were determined for each isolate. GPS data of the sampling sites were used to map flies carrying ESBL-E and S. aureus. Overall, Serratia fonticola (123/1346; 9.1%) was the most prevalent ESBL-E in flies, followed by E. coli (44/1346; 3.3%). A high proportion of flies was positive for ESBL-producing E. coli (15.0-22.2%) in a rural area. CTX-M-1 was the most prevalent beta-lactamase in E. coli (38.6%). One livestock-associated methicillin resistant S. aureus (LA-MRSA, t011/ST398) was found in the city centre of Münster. Overall, a substantial part of ESBL-producing E. coli and S. aureus from flies and humans showed a similar genetic background. In conclusion, flies can carry ESBL-E and LA-MRSA in urban and rural areas. The similar genetic background of isolates from humans and flies points towards a common source.

[Multidrug-resistant bacteria in Germany. The impact of sources outside healthcare facilities]. / Antibiotika-resistente Erreger in Deutschland. Die Rolle von nicht nosokomialen Ansteckungsquellen.

BACKGROUND: Currently, there is an ongoing discussion about the question whether the emergence of multidrug-resistant microorganisms (MDRO) among humans is due to transfer of these bacteria from animals. OBJECTIVES: This review summarizes data on the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL) producing enterobacteria in animals and humans, and describes knowledge about transmission pathways. MATERIAL AND METHODS: After a scientific literature analysis, relevant articles were identified by screening of titles and abstracts, amended by publications of infection control authorities and the respective reference lists. RESULTS: MDRO are both transmitted in the nosocomial setting and are increasingly detected as sources of infection outside healthcare facilities. CONCLUSIONS: Due to new transmission pathways of MDRO an inter-disciplinary approach towards prevention is necessary, involving medical, pharmaceutical and veterinary expertise.

Are cases of Methicillin-resistant Staphylococcus aureus clonal complex (CC) 398 among humans still livestock-associated?

UNLABELLED: Methicillin-resistant Staphylococcus aureus (MRSA) of clonal complex (CC) 398 are widespread among pigs, cattle and poultry as well as among humans who have contact to these livestock animals. However, there is limited data on livestock-independent dissemination of MRSA CC398 in the general population. METHODS: In this case-control study MRSA isolates derived (between July 2013 and June 2014) from patients of four hospitals located in a livestock-dense region were S. aureus protein A (spa) typed and risk factors for MRSA acquisition were assessed from patients colonized or infected with MRSA CC398 vs. other MRSA molecular types (MRSA non-CC398). RESULTS: Of 384 patients, 21% were colonized with MRSA CC398. Contact with livestock (Odds Ratio (OR) 46.03) and residence directly on a pig farm (OR 12.82) were associated with MRSA CC398. Of 55 patients with MRSA CC398, 21 (38%) did not report direct livestock contact. Among the latter we identified several risk factors that could have facilitated indirect transmission, such as living on farms (without being farmer), private contact with known MRSA carriers or previous hospitalization. DISCUSSION: This study suggests that MRSA CC398 is still mostly disseminated via direct contact to livestock. However, a substantial proportion of patients seem to acquire MRSA CC398 via other pathways.

[Blood culture diagnostic--challenge or routine standard of care?]. / Sepsis und Multiorganversagen - Blutkulturdiagnostik: Herausforderung oder Routine?

Blood cultures are an essential diagnostic tool to investigate suspected cases of sepsis. However, several studies indicate that (compared with other countries) blood culture diagnostics is only rarely performed in German healthcare facilities. Reasons for this are unknown, but could include clinicians' perception that the turn-around time of results is delayed or that contamination rates are high. Therefore, this article aims to summarize important aspects involved in assuring quality of blood culture diagnostics as well as innovative approaches.

Methicillin resistance in Staphylococcus isolates: the "mec alphabet" with specific consideration of mecC, a mec homolog associated with zoonotic S. aureus lineages.

Livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) have globally emerged during the past decade. In Europe, this was particularly due to the occurrence of LA-MRSA strains associated with the clonal complex (CC) 398 as defined by multilocus sequence typing. However, more recently animal-adapted clonal lineages of S. aureus showing phenotypic methicillin resistance have been identified such as CC130, CC599, CC59, CC1943 and CC425. These newly emerging LA-MRSA CCs/STs caused infections in animals and zoonoses in humans. In contrast to other S. aureus clonal lineages, the methicillin resistance of the latter CCs/STs is based on a mecA gene homolog, designated mecC, which is part of a distinct SCCmec type (SCCmec XI). Including mecB found in Macrococcus caseolyticus, henceforth, the "mec alphabet" comprises three major gene types with several allotypes. As known for mecA, the gene homolog mecC is also not restricted to S. aureus, but found in several staphylococcal species including S. sciuri, S. stepanovicii and S. xylosus (mecC1 allotype). First investigations showed a wide geographical distribution of mecC-MRSA in Europe and a broad diversity of host species including livestock, companion and wildlife animals. In particular, wild rodents and insectivores might serve as reservoir for staphylococci harboring mecC. Economic burden may be caused by mastitis of dairy cattle. Livestock animals may likely serve as source for human infections with mecC-MRSA; reported cases comprise skin and soft tissue infections, osteomyelitis and bacteremia. Due to the divergent molecular nature of mecC-MRSA, its diagnostics is hampered by difficulties to verify the methicillin resistance using phenotypic as well as DNA-based procedures, which could have negative consequences for therapy of mecC-MRSA-caused infections.

LA-MRSA CC398 differ from classical community acquired-MRSA and hospital acquired-MRSA lineages: functional analysis of infection and colonization processes.

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) of the clonal complex (CC) 398 became primarily known as colonizers of livestock animals. In the past few years, they have been increasingly introduced into hospitals with subsequent emergence of human infections. However, the (re-)adaptation to the human host is only incompletely understood. This study aimed to assess virulence properties of LA-MRSA CC398 by functional modeling of infection and colonization processes. A selection of 15 human LA-MRSA CC398 isolates and 11 pig-colonizing isolates were characterized regarding their virulence capacities and compared with human isolates of hospital-acquired (HA)-MRSA (CC5, CC22 and CC45) and community-associated (CA)-MRSA (CC8, CC30 and CC80) clonal lineages. Our investigations demonstrated that LA-MRSA CC398 adhered less efficient to human cells and human/bovine plasma fibronectin than CA-MRSA and HA-MRSA isolates. In contrast, the LA-MRSA CC398 isolates revealed a high cytotoxic potential comparable to certain CA-MRSA. Comparing the most prevalent LA-MRSA CC398 spa types (t011, t034, t108), isolates associated with spa t108 showed an increased adhesive and invasive potential paired with an increased ability to evade phagocytosis. The results underline both the pathogenic potential of LA-MRSA in general and the heterogeneity within the CC398 clade regarding the virulence characteristics of CC398 subpopulations. Assuming an ongoing (re-)adaptation to the human host combined with a huge reservoir of LA-MRSA CC398 in livestock and constant zoonotic transmission, the LA-MRSA CC398 lineage has the potential to pose a serious threat to human health.

The risk to import ESBL-producing Enterobacteriaceae and Staphylococcus aureus through chicken meat trade in Gabon.

BACKGROUND: A main export market for chicken meat from industrialized countries is sub-Saharan Africa. We hypothesized that antibiotic resistant bacteria could be exported to developing countries through chicken meat trade. The objective was to investigate the occurrence and molecular types of ESBL-producing Enterobacteriaceae and Staphylococcus aureus in chicken meat in Gabon and to assess their dissemination among humans. RESULTS: Frozen chicken meat samples imported from industrialized countries to Gabon (n = 151) were screened for ESBL-producing Enterobacteriaceae and S. aureus. Genotypes and resistance genes (SHV, TEM, CTX-M, CMY-2) of isolates from meat were compared with isolates derived from humans. The contamination rate per chicken part (i. e. leg, wing) with ESBL-producing Escherichia coli (ESBL E. coli, no other ESBL-producing Enterobacteriaceae were found) and S. aureus was 23% and 3%, respectively. The beta-lactamase CTX-M 1 was predominant in ESBL E. coli from meat samples but was not found in isolates from cases of human colonization or infection. S. aureus belonging to spa type t002 (multilocus sequence type ST5) were found both in chicken meat and humans. CONCLUSION: There is a risk to import ESBL E. coli to Gabon but molecular differences between isolates from humans and chicken meat argue against a further dissemination. No MRSA isolate was detected in imported chicken meat.

Enterohemorrhagic Escherichia coli O26:H11/H-: a new virulent clone emerges in Europe.

BACKGROUND: Enterohemorrhagic Escherichia coli (EHEC) O26 causes diarrhea and hemolytic uremic syndrome (HUS). Strains harboring the stx1a gene prevail, but strains with stx2a as the sole Shiga toxin-encoding gene are now emerging. The traits and virulence of the latter set of strains are unknown. We correlated stx genotypes of 272 EHEC O26 strains isolated in 7 European countries between 1996 and 2012 with disease phenotypes. We determined phylogeny, clonal structure, and plasmid gene profiles of the isolates and portray geographic and temporal distribution of the different subgroups. METHODS: The stx genotypes and plasmid genes were identified using polymerase chain reaction, phylogeny was assigned using multilocus sequence typing, and clonal relatedness was established using pulsed-field gel electrophoresis. RESULTS: Of the 272 EHEC O26 isolates, 107 (39.3%), 139 (51.1%), and 26 (9.6%) possessed stx1a, stx2a, or both genes, respectively. Strains harboring stx2a only were significantly associated with HUS (odds ratio, 14.2; 95% confidence interval, 7.9-25.6; P < .001) compared to other stx genotypes. The stx2a-harboring strains consist of 2 phylogenetically distinct groups defined by sequence type (ST) 21 and ST29. The ST29 strains are highly conserved and correspond by plasmid genes to the new virulent clone of EHEC O26 that emerged in Germany in the 1990s. This new clone occurred in 6 of the 7 countries and represented approximately 50% of all stx2a-harboring EHEC O26 strains isolated between 1996 and 2012. CONCLUSIONS: A new highly virulent clone of EHEC O26 has emerged in Europe. Its reservoirs and sources warrant identification.

Novel organization of the arginine catabolic mobile element and staphylococcal cassette chromosome mec composite island and its horizontal transfer between distinct Staphylococcus aureus genotypes.

In this study, 425 methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered in the Dutch-German Euregio were investigated for the presence of the arginine catabolic mobile element (ACME). Sequence analysis by whole-genome sequencing revealed an entirely new organization of the ACME-staphylococcal cassette chromosome mec composite island (SCCmec-CI), with truncated ACME type II located downstream of SCCmec. An identical nucleotide sequence of ACME-SCCmec-CI was found in two distinct MRSA lineages (t064-ST8 and t002-ST5), which has not been reported previously in S. aureus.