Angelika Fruth

Robert Koch Institut, Berlín, Berlin, Germany

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Publications (117)504.33 Total impact

  • Angelika Fruth · Rita Prager · Erhard Tietze · Wolfgang Rabsch · Antje Flieger ·
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    ABSTRACT: Infections by intestinal pathogenic Escherichia coli (E. coli) are among those causing a high mortality and morbidity due to diarrheal disease and post infection sequelae worldwide. Since introduction of the Infection Protection Act in Germany 2001, these pathogens rank third among bacterial infections of the gastrointestinal tract. As a major pathovar Shiga toxin-producing E. coli (STEC) which include enterohemorrhagic E. coli (EHEC) play a leading role in occurrence of sporadic cases and disease outbreaks. An outstanding example is the large outbreak in spring 2011 caused by EHEC/EAEC O104:H4. To monitor and trace back STEC infections, national surveillance programs have been implemented including activities of the German National Reference Centre for Salmonella and other Enteric Bacterial Pathogens (NRC). This review highlights advances in our understanding of STEC in the last 20 years of STEC surveillance by the NRC. Here important characteristics of STEC strains from human infections and outbreaks in Germany between 1997 and 2013 are summarized.
    International journal of medical microbiology: IJMM 09/2015; 305(7). DOI:10.1016/j.ijmm.2015.08.020 · 3.61 Impact Factor
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    ABSTRACT: The highly virulent Escherichia coli O104:H4 that caused the large 2011 outbreak of diarrhoea and haemolytic uraemic syndrome secretes blended virulence factors of enterohaemorrhagic and enteroaggregative E. coli, but their secretion pathways are unknown. We demonstrate that the outbreak strain releases a cocktail of virulence factors via outer membrane vesicles (OMVs) shed during growth. The OMVs contain Shiga toxin (Stx) 2a, the major virulence factor of the strain, Shigella enterotoxin 1, H4 flagellin, and O104 lipopolysaccharide. The OMVs bind to and are internalised by human intestinal epithelial cells via dynamin-dependent and Stx2a-independent endocytosis, deliver the OMV-associated virulence factors intracellularly and induce caspase-9-mediated apoptosis and interleukin-8 secretion. Stx2a is the key OMV component responsible for the cytotoxicity, whereas flagellin and lipopolysaccharide are the major interleukin-8 inducers. The OMVs represent novel ways for the E. coli O104:H4 outbreak strain to deliver pathogenic cargoes and injure host cells.
    Scientific Reports 08/2015; 5:13252. DOI:10.1038/srep13252 · 5.58 Impact Factor
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    ABSTRACT: Thermophilic Campylobacter species colonize the intestine of agricultural and domestic animals commensally, but cause severe gastroenteritis in humans. In contrast to other enteropathogenic bacteria, Campylobacter have been considered to be non-glycolytic, a metabolic property originally used for their taxonomic classification. Contrary to this dogma, we demonstrate that several Campylobacter coli strains are able to utilize glucose as a growth substrate. Isotopologue profiling experiments with (13) C-labeled glucose suggested that these strains catabolize glucose via the pentose phosphate and Entner-Doudoroff (ED) pathways and use glucose efficiently for de novo synthesis of amino acids and cell surface carbohydrates. Whole genome sequencing of glycolytic C. coli isolates identified a genomic island located within a ribosomal RNA gene cluster that encodes for all ED pathway enzymes and a glucose permease. We could show in vitro that a non-glycolytic C. coli strain could acquire glycolytic activity through natural transformation with chromosomal DNA of C. coli and C. jejuni subsp. doylei strains possessing the ED pathway encoding plasticity region. These results reveal for the first time the ability of a Campylobacter species to catabolize glucose and provide new insights into how genetic macrodiversity through intra- and interspecies gene transfer expand the metabolic capacity of this food-borne pathogen. This article is protected by copyright. All rights reserved.
    Molecular Microbiology 08/2015; DOI:10.1111/mmi.13159 · 4.42 Impact Factor
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    ABSTRACT: Enterohemorrhagic Escherichia coli (EHEC) are causative agents of bloody diarrhea and extraintestinal sequelae in humans, most importantly the hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Besides the bacteriophage-encoded Shiga toxin gene (stx), EHEC harbor the locus of enterocyte effacement (LEE), which confers the ability to cause attaching and effacing lesions. Currently the vast majority of EHEC-infections are caused by strains belonging to five O-serogroups ("big five") that comprise, in addition to the most important EHEC O-serogroup O157, the O-serogroups O26, O103, O111, and O145. We hypothesize that these four non-O157 EHEC have different phylogenies.To test this hypothesis, by multilocus sequence typing (MLST) we analyzed a large collection of 250 isolates of these four O-serogroups, which were isolated from diseased as well healthy humans and cattle between 1952 and 2009.The majority of the EHEC isolates of O-serogroups O26 and O111 clustered into one sequence type complex, STC29. Isolates of O103 clustered mainly in STC20 and most isolates of O145 were found within STC32. In addition to these EHEC strains, STC29 also included stx-negative E. coli, termed atypical enteropathogenic E. coli (aEPEC), yet another group of intestinal pathogenic E. coli.The finding that aEPEC and EHEC isolates of non-O157 O-serogroups share the same phylogeny suggests an ongoing microevolutionary scenario, in which the phage-encoded Shiga Toxin gene stx is transferred between aEPEC and EHEC. In consequence, aEPEC of STC29 can be regarded as post- or pre-EHEC isolates. Therefore STC29 incorporates phylogenetic information useful for unraveling the evolution of EHEC. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
    Applied and Environmental Microbiology 07/2015; 81(20). DOI:10.1128/AEM.01921-15 · 3.67 Impact Factor
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    ABSTRACT: In January 2013, the National Reference Centre for Salmonella (NRC) detected a salmonellosis cluster in Saxony-Anhalt, Germany, caused by uncommon O4 non-agglutinating, monophasic Salmonella (S.) Typhimurium DT193. Circulating predominant monophasic S. Typhimurium DT193 clones typically display resistance phenotype ASSuT. We investigated common exposures to control the outbreak, and conducted microbiological investigations to assess the strains' phenotype. We conducted a case-control study defining cases as persons living or working in Saxony-Anhalt diagnosed with the O4 non-agglutinating strain between January and March 2013. We selected two controls contemporarily reported with norovirus infection, frequency-matched on residence and age group, per case. We interviewed regarding food consumption, especially pork and its place of purchase. We calculated odds ratios (ORs) with 95% confidence intervals (95% CI) using logistic regression. The NRC investigated human and food isolates by PCR, SDS-PAGE, MLST, PFGE, MLVA and susceptibility testing. Altogether, 68 O4 non-agglutinating human isolates were confirmed between January and April 2013. Of those, 61 were assigned to the outbreak (median age 57 years, 44% female); 83% cases ≥ 60 years were hospitalized. Eating raw minced pork from butcheries within 3 days was associated with disease (31 cases, 28 controls; OR adjusted for sex: 3.6; 95% CI: 1.0-13). Phage type DT193 and MLST ST34 were assigned, and isolates' lipopolysaccharide (LPS) matched control strains. Isolates linked to Saxony-Anhalt exhibited PFGE type 5. ASSuT- and ACSSuT phenotype proportions were 34 and 39% respectively; 54% were resistant to chloramphenicol. Three pork isolates matched the outbreak strain. Raw minced pork was the most likely infection vehicle in this first reported outbreak caused by O4 non-agglutinating, mostly chloramphenicol-resistant S. Typhimurium DT193. High hospitalization proportions demand awareness on the risk of consumption of raw pork among elderly. LPS analysis indicated O4 expression; therefore, testing with antisera from different lots is recommendable in unexpected agglutination reactions.
    PLoS ONE 06/2015; 10(6):e0128349. DOI:10.1371/journal.pone.0128349 · 3.23 Impact Factor
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    ABSTRACT: A large outbreak of gastrointestinal disease occurred in 2011 in Germany which resulted in almost 4000 patients with acute gastroenteritis or hemorrhagic colitis, 855 cases of a hemolytic uremic syndrome and 53 deaths. The pathogen was an uncommon, multiresistant Escherichia coli strain of serotype O104:H4 which expressed a Shiga toxin characteristic of enterohemorrhagic E. coli and in addition virulence factors common to enteroaggregative E. coli. During post-epidemic surveillance of Shiga toxin-producing E. coli (STEC) all but two of O104:H4 isolates were indistinguishable from the epidemic strain. Here we describe two novel STEC O104:H4 strains isolated in close spatiotemporal proximity to the outbreak which show a virulence gene panel, a Shiga toxin-mediated cytotoxicity towards Vero cells and aggregative adherence to Hep-2 cells comparable to the outbreak strain. They differ however both from the epidemic strain and from each other, by their antibiotic resistance phenotypes and some other features as determined by routine epidemiological subtyping methods. Whole genome sequencing of these two strains, of ten outbreak strain isolates originating from different time points of the outbreak and of one historical sporadic EHEC O104:H4 isolate was performed. Sequence analysis revealed a clear phylogenetic distance between the two variant strains and the outbreak strain finally identifying them as epidemiologically unrelated isolates from sporadic cases. These findings add to the knowledge about this emerging pathogen, illustrating a certain diversity within the bacterial core genome as well as loss and gain of accessory elements. Our results do also support the view that distinct new variants of STEC O104:H4 repeatedly might originate from yet unknown reservoirs, rather than that there would be a continuous diversification of a single epidemic strain established and circulating in Germany after the large outbreak in 2011.
    PLoS ONE 04/2015; 10(4):e0122074. DOI:10.1371/journal.pone.0122074 · 3.23 Impact Factor
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    ABSTRACT: In 2011, the Shiga toxin- and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli O104:H4 caused a serious outbreak of gastroenteritis in Germany. This strain carried blaCTX-M-15 and blaTEM-1 on an IncI1-ST31 plasmid. During screening of individuals at risk for acquisition of the epidemic E. coli O104:H4, we isolated another ESBL-producing and Shiga toxin-positive E. coli belonging to serotype O91:H14 from feces of a human patient. Interestingly, the patient also carried a further ESBL-producing but Shiga toxin-negative E. coli. Both strains harbored blaCTX-M-15 and blaTEM-1 on an IncI1-ST31 plasmid, which was indistinguishable regarding size and plasmid restriction pattern from the plasmid of the epidemic E. coli O104:H4 strain. The patient had traveled to India 6 months prior to the isolation of the E. coli strains. This is the first report of an ESBL-producing, Shiga toxin-positive E. coli of serogroup O91. Our data suggest a high propensity of the IncI1-ST31 plasmid to spread in the human and/or animal population. Copyright © 2015 Elsevier GmbH. All rights reserved.
    International journal of medical microbiology: IJMM 03/2015; 305(3). DOI:10.1016/j.ijmm.2015.03.003 · 3.61 Impact Factor
  • W. Rabsch · A. Fruth · S. Simon · I. Szabo · B. Malorny ·
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    ABSTRACT: Salmonellosis is one of the most common foodborne diseases and is caused by different serovars of the species Salmonella enterica. More than 2600 different Salmonella serovars have been identified to date. Salmonella is an ubiquitous and quite tenacious bacterium that can survive for years in dry environments by transition into a dormant state or biofilm formation. S. enterica serovars are often associated with animal reservoirs and outbreak investigations reveal that infections in humans constantly result from animal to human transmission. The food vehicles most commonly involved are chicken and poultry, pork, beef, eggs, and seafood. Meat or egg products may contain bacteria either because animals had been infected or because fecal contamination occurred during processing. In the last years, Salmonella infections have been increasingly linked to the consumption of vegetables and fruits. Plant products can be contaminated with Salmonella in the field through application of manure, fertilizers or contaminated water. Also reptiles, rodents and insects can contaminate the herbs and spices in the country of origin before their worldwide distribution. The serovars S. Enteritidis and S. Typhimurium are the two most important serovars transmitted from animals to humans in Germany. The classical discrimination by phage typing combined with different molecular methods, e. g. ribotyping or macrorestriction analysis help us to link patients isolates with a common source and therefore to identify and trace back an outbreak back to its origin. This chapter focuses mainly on food-borne Salmonella infections. However, since “Reptile-Exotic-Pet-Associated-Salmonellosis” (REPAS) is of increasing concern we summarize our current knowledge of REPAS.
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    ABSTRACT: An exploratory study in five conventional pig production clusters was carried out to investigate the dynamic and diversity of Salmonella spp. within different production stages and sample site categories (pooled feces, direct and non-direct environment). Observing two production cycles per production cluster, a total of 1,276 samples were collected along the pig production chain. Following a microbiological examination via culture, 2,246 subcultures were generated out of 285 Salmonella positive samples and analysed by pheno- and genotyping methods. Based on a combination of serotyping, MLVA (multiple-locus variable-number tandem repeat (VNTR) analysis), PFGE (pulse-field gel electrophoresis) and MLST (multilocus sequence typing), an amount of 22.3% Salmonella positive samples were characterized in clonal lineages and its variants.
    Veterinary Microbiology 12/2014; 176(1-2). DOI:10.1016/j.vetmic.2014.12.005 · 2.51 Impact Factor
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    ABSTRACT: Background The mutS-rpoS intergenic region in E. coli displays a mosaic structure which revealed pathotype specific patterns. To assess the importance of this region as a surrogate marker for the identification of highly virulent extraintestinal pathogenic E. coli (ExPEC) strains we aimed to: (i) characterize the genetic diversity of the mutS gene and the o454-nlpD genomic region among 510 E. coli strains from animals and humans; (ii) delineate associations between the polymorphism of this region and features such as phylogenetic background of E. coli, pathotype, host species, clinical condition, serogroup and virulence associated genes (VAG)s; and (iii) identify the most important VAGs for classification of the o454-nlpD region. Methods Size variation in the o454-nlpD region was investigated by PCR amplification and sequencing. Phylogenetic relationships were assessed by Ecor- and Multilocus sequence- typing (MLST), and a comparative analysis between mutS gene phylogenetic tree obtained with RAxML and the MLST grouping method was performed. Correlation between o454-nlpD patterns and the features described above were analysed. In addition, the importance of 47 PCR-amplified ExPEC-related VAGs for classification of o454-nlpD patterns was investigated by means of Random Forest algorithm. Results Four main structures (patterns I-IV) of the o454-nlpD region among ExPEC and commensal E. coli strains were identified. Statistical analysis showed a positive and exclusive association between pattern III and the ExPEC strains. A strong association between pattern III and either the Ecor group B2 or the sequence type complexes known to represent the phylogenetic background of highly virulent ExPEC strains (such as STC95, STC73 and STC131) was found as well. RF analyses determined five genes (csgA, malX, chuA, sit, and vat) to be suitable to predict pattern III strains. Conclusion The significant association between pattern III and group B2 strains suggested the o454-nlpD region to be of great value in identifying highly virulent strains among the mixed population of E. coli promising to be the basis of a future typing tool for ExPEC and their gut reservoir. Furthermore, top-ranked VAGs for classification and prediction of pattern III were identified. These data are most valuable for defining ExPEC pathotype in future in vivo assays.
    Gut Pathogens 09/2014; 6. DOI:10.1186/s13099-014-0037-x · 2.28 Impact Factor
  • R. Hofmann · W. Rabsch · A. Fruth · B. Neubauer · A. Hahn ·

    Neuropediatrics 09/2014; 45(S 01). DOI:10.1055/s-0034-1390611 · 1.24 Impact Factor
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    ABSTRACT: Salmonella enterica serovar Kottbus has been continuously isolated from poultry and poultry meat, especially from turkey. We investigated by comparative molecular typing 95 S. Kottbus isolates obtained in Germany between 2000 and 2011 from poultry/poultry meat, pig/pork, cattle, reptiles, the environment as well as from human cases to identify potential infection sources for humans, especially the role of poultry and poultry products as vehicle in transmission of S. Kottbus isolates to humans. Multilocus sequence typing analysis detected three main genetic lineages. Most human isolates belonged to lineage 1 represented by sequence types ST212 and ST808. Part of the isolates isolated from cattle and pork were also linked to this lineage. Nevertheless, human isolates and especially isolates from poultry/poultry meat, and with less extend from other livestock, grouped in lineage 2 represented by ST582. Four additional isolates from reptiles and humans belonging to ST1669 represented the third lineage. The three lineages were also reflected by pulsed-field gel electrophoresis typing data and DNA microarray analysis of 102 pathogenicity genes. Antimicrobial resistance especially to nalidixic acid and ciprofloxacin was predominantly observed in isolates assigned to lineage 2, which contains predominantly resistant isolates compared to lineage 1 and 3. Sequencing of the quinolone resistance-determining region of gyrA revealed a point mutation in codon 83 or 87 responsible for nalidixic acid resistance and MIC values for ciprofloxacin between 0.125 and 0.25 mg/l. Overall, this study showed that in Germany a specific S. Kottbus lineage (ST582), which is well-established in poultry, can be transmitted to humans by poultry meat and, consequently, poses a risk for human health.
    Veterinary Microbiology 05/2014; 170(1-2). DOI:10.1016/j.vetmic.2014.01.020 · 2.51 Impact Factor
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    ABSTRACT: The so far highest number of life-threatening hemolytic uremic syndrome was associated with a food-borne outbreak in 2011 in Germany which was caused by an enterohemorrhagic Escherichia coli (EHEC) of the rare serotype O104:H4. Most importantly, the outbreak strain harbored genes characteristic of both EHEC and enteroaggregative E. coli (EAEC). Such strains have been described seldom but due to the combination of virulence genes show a high pathogenicity potential. To evaluate the importance of EHEC/EAEC hybrid strains in human disease, we analyzed the EHEC strain collection of the German National Reference Centre for Salmonella and other Bacterial Enteric Pathogens (NRC). After exclusion of O104:H4 EHEC/EAEC strains, out of about 2400 EHEC strains sent to NRC between 2008 and 2012, two strains exhibited both EHEC and EAEC marker genes, specifically were stx2 and aatA positive. Like the 2011 outbreak strain, one of the novel EHEC/EAEC harbored the Shiga toxin gene type stx2a. The strain was isolated from a patient with bloody diarrhea in 2010, was serotyped as O59:H-, belonged to MLST ST1136, and exhibited genes for type IV aggregative adherence fimbriae (AAF). The second strain was isolated from a patient with diarrhea in 2012, harbored stx2b, was typed as Orough:H-, and belonged to MLST ST26. Although the strain conferred the aggregative adherence phenotype, no known AAF genes corresponding to fimbrial types I to V were detected. In summary, EHEC/EAEC hybrid strains are currently rarely isolated from human disease cases in Germany and two novel EHEC/EAEC of rare serovars/MLST sequence types were characterized.
    PLoS ONE 04/2014; 9(4):e95379. DOI:10.1371/journal.pone.0095379 · 3.23 Impact Factor

  • Journal of Antimicrobial Chemotherapy 03/2014; 69(7). DOI:10.1093/jac/dku042 · 5.31 Impact Factor
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    ABSTRACT: We report on a 65-year-old male patient with a Shiga toxin-producing Escherichia coli O51:H49 gastrointestinal infection and sepsis associated with hemolytic uremic syndrome (HUS) with a fatal outcome. The strains isolated harbored stx2e and eae, a very unusual and new virulence profile for an HUS-associated enterohemorrhagic E. coli.
    Journal of clinical microbiology 02/2014; 52(4). DOI:10.1128/JCM.03459-13 · 3.99 Impact Factor
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    ABSTRACT: Extraintestinal pathogenic and intestinal pathogenic (diarrheagenic) Escherichia coli differ phylogenetically and by virulence profiles. Classic theory teaches simple linear descent in this species, where non-pathogens acquire virulence traits and emerge as pathogens. However, diarrheagenic Shiga toxin-producing E. coli (STEC) O2:H6 not only possess and express virulence factors associated with diarrheagenic and uropathogenic E. coli but also cause diarrhea and urinary tract infections. These organisms are phylogenetically positioned between members of an intestinal pathogenic group (STEC) and extraintestinal pathogenic E. coli. STEC O2:H6 is, therefore, a ‘heteropathogen,’ and the first such hybrid virulent E. coli identified. The phylogeny of these E. coli and the repertoire of virulence traits they possess compel consideration of an alternate view of pathogen emergence, whereby one pathogroup of E. coli undergoes phased metamorphosis into another. By understanding the evolutionary mechanisms of bacterial pathogens, rational strategies for counteracting their detrimental effects on humans can be developed. Subject Categories Microbiology, Virology & Host Pathogen Interaction
    EMBO Molecular Medicine 01/2014; 6(3). DOI:10.1002/emmm.201303133 · 8.67 Impact Factor
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    ABSTRACT: To discern the relevance of ST648 extended-spectrum β-lactamase (ESBL)-producing Escherichia coli as a putative new group of multiresistant and extraintestinal pathogenic strains in animals, its frequency, ESBL types, antimicrobial resistance patterns and virulence gene (VG) profiles should be determined and compared with ST131 strains from the same collection of strains. ESBL-producing E. coli isolates (n = 1152), consecutively sampled from predominantly dogs, cats and horses between 2008 and 2011, were assigned to a phylogenetic group by PCR. Partial multilocus sequence typing was performed for group D and B2 strains and strains presumed to be D-ST648 and B2-ST131 were fully typed. ESBL genes and extraintestinal pathogenic E. coli (ExPEC)-like VGs were characterized by PCR and sequence analysis and antimicrobial resistance was determined by broth dilution. Clonal analysis was done by PFGE. Forty (3.5%) ESBL-producing E. coli were determined as D-ST648, whereas B2-ST131 isolates occurred less frequently (2.8%). Although the predominant ESBL type in both groups was CTX-M-15 (72.5% versus 46.9%), ST648 strains from companion animals and horses displayed a lower variety of ESBL types (CTX-M-1, -3, -14, -15 and -61 versus CTX-M-1,-2,-14,-15,-27 and -55 and SHV-12). In contrast to ST131 strains, a higher proportion of ST648 strains showed resistance to most non-β-lactam antibiotics. Overall, VGs were less abundant in ST648 strains, although some strains had VG profiles comparable to those of ST131 strains. ExPEC-associated serotype O1:H6 was predominant (46.8%) among the ST648 strains. Some PFGE clusters comprised ST648 isolates from pets, horses and wild birds and humans included from previous studies. Our findings demonstrate that certain subgroups of E. coli D-ST648-CTX-M may represent a novel genotype that combines multiresistance, extraintestinal virulence and zoonotic potential.
    Journal of Antimicrobial Chemotherapy 01/2014; 69(5). DOI:10.1093/jac/dkt516 · 5.31 Impact Factor
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    M Pees · W Rabsch · B Plenz · A Fruth · R Prager · S Simon · V Schmidt · S Munch · Pg Braun ·
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    ABSTRACT: This study examines the Salmonella status in reptiles kept in households with children suffering from gastroenteritis due to an exotic Salmonella serovar, to obtain information on possible transmission paths. A number of affected households (n=79) were contacted, and almost half (34/79) comprised at least one reptile in the home. Of the households, 19 were further studied, whereby a total of 36 reptiles were investigated. Samples were taken from the reptiles including the oral cavity, the cloaca, the skin and, in the case of lizards, the stomach, and isolation of Salmonella strains was performed using repeated enrichment and typing. Where the Salmonella serovars of the infected child and the reptile were identical, typing was followed by pulsed-field gel electrophoresis (PFGE). Bearded dragons (Pogona vitticeps) constituted 19 of 36 examined reptiles. Altogether 319 Salmonella isolates were investigated and 24 different serovars identified in the reptiles. In 15 of 19 households, an identical serovar to the human case was confirmed in at least one reptile (including 16 of all 19 bearded dragons examined). The results demonstrate that reptiles and especially bearded dragons shed various Salmonella serovars including those isolated from infected children in the respective households. Hygiene protocols and parents' education are therefore highly necessary to reduce the risk of transmission. From a terminological point of view, we propose to call such infections 'Reptile-Exotic-Pet-Associated-Salmonellosis' (REPAS).
    Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 11/2013; 18(46). DOI:10.2807/1560-7917.ES2013.18.46.20634 · 5.72 Impact Factor
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    ABSTRACT: Uropathogenic Escherichia coli (UPEC) are the most common cause of community and hospital-acquired urinary tract infections (UTIs). Isolates from community-acquired, uncomplicated UTIs express a variety of virulence traits which promote efficient colonization of the urinary tract. In contrast, nosocomial UTIs can be caused by E.coli strains which differ in their virulence traits from community-acquired UTI isolates. UPEC virulence markers are used to distinguish these facultative extraintestinal pathogens, which belong to the intestinal flora of many healthy individuals, from intestinal pathogenic E.coli (IPEC). IPEC are diarrheagenic pathogens with characteristic virulence gene sets which are absent in UPEC. Here, we characterized 265 isolates from patients with UTI during inpatient or outpatient treatment at a hospital regarding phylogeny and IPEC or UPEC virulence traits. Interestingly, 28 of these isolates (10.6%) carried typical IPEC virulence genes characteristic for enteroaggregative E.coli (EAEC), Shiga toxin-producing E.coli (STEC), and atypical enteropathogenic E.coli (aEPEC), although IPEC are not considered uropathogens. Twenty-three isolates harbored the astA gene coding for the EAEC heat-stable enterotoxin 1 (EAST1), and most of them carried characteristic virulence genes of UPEC and/or EAEC. Our results indicate that UPEC from hospital patients can differ from archetypal community-acquired isolates of uncomplicated UTI by the spectrum of virulence traits. They represent a diverse group, including EAEC, as well as other IPEC pathotypes, which, in addition, contain typical UPEC virulence genes. The combination of typical ExPEC and IPEC virulence determinants in some isolates demonstrates the marked E.coli genome plasticity and calls for re-evaluating the strict pathotype classification of EAEC.
    Journal of clinical microbiology 11/2013; 52(2). DOI:10.1128/JCM.02069-13 · 3.99 Impact Factor
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    ABSTRACT: Yersinia enterocolitica is a food-borne, gastro-intestinal pathogen with world-wide distribution. Only 11 serotypes have been isolated from patients, with O:3, O:9, O:8 and O:5,27 being the serotypes most commonly associated with human yersiniosis. Serotype is an important characteristic of Y. enterocolitica strains, allowing differentiation for epidemiology, diagnosis and phylogeny studies. Conventional serotyping, performed by slide agglutination, is a tedious and laborious procedure whose interpretation tends to be subjective, leading to poor reproducibility. Here we present a PCR-based typing scheme for molecular identification and patho-serotyping of Y. enterocolitica. Genome-wide comparison of Y. enterocolitica sequences allowed analysis of the O-antigen gene clusters of different serotypes, uncovering their formerly unknown genomic locations, and selection of targets for serotype-specific amplification. Two multiplex PCRs and one additional PCR were designed and tested on various reference strains and isolates from different origins. Our genotypic assay proved to be highly specific for identification of Y. enterocolitica species, discrimination between virulent and non-virulent strains, distinguishing the main human-related serotypes, and typing of conventionally untypeable strains. This genotyping scheme could be applied in microbiology laboratories as an alternative or complementary method to the traditional phenotypic assays, providing data for epidemiological studies.
    International journal of medical microbiology: IJMM 10/2013; 304(3-4). DOI:10.1016/j.ijmm.2013.10.007 · 3.61 Impact Factor

Publication Stats

3k Citations
504.33 Total Impact Points


  • 1995-2015
    • Robert Koch Institut
      • Department for Infectious Disease Epidemiology
      Berlín, Berlin, Germany
  • 2007-2012
    • University of Münster
      • • Institute of Hygiene
      • • Institute of Food Chemistry
      Muenster, North Rhine-Westphalia, Germany
  • 2010
    • Friedrich Loeffler Institute
      • Institute of Molecular Pathogenesis
      Griefswald, Mecklenburg-Vorpommern, Germany
  • 2006
    • Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit
      Erlangen, Bavaria, Germany