Publications

salmonella typhimurium st213 is associated with two types of inca/c plasmids carrying multiple resistance determinants.	salmonella typhimurium st213 was first detected in the mexican typhimurium population in 2001. it is associated with a multi-drug resistance phenotype and a plasmid-borne blacmy-2 gene conferring resistance to extended-spectrum cephalosporins. the objective of the current study was to examine the association between the st213 genotype and blacmy-2 plasmids.	2011	21223599
factors related to the prevalence of pathogenic yersinia enterocolitica on pig farms.	summarya survey of 788 pigs from 120 farms was conducted to determine the within-farm prevalence of pathogenic yersinia enterocolitica and a questionnaire of management conditions was mailed to the farms afterwards. a univariate statistical analysis with carriage and shedding as outcomes was conducted with random-effects logistic regression with farm as a clustering factor. variables with a p value <0â·15 were included into the respective multivariate random-effects logistic regression model. th ...	2011	21226982
tapping the potential of intact cell mass spectrometry with a combined data analytical approach applied to yersinia spp.: detection, differentiation and identification of y. pestis.	in the everyday routine of an analytic lab, one is often confronted with the challenge to identify an unknown microbial sample lacking prior information to set the search limits. in the present work, we propose a workflow, which uses the spectral diversity of a commercial database (saramis) to narrow down the search field at a certain taxonomic level, followed by a refined classification by supervised modelling. as supervised learning algorithm, we have chosen a shrinkage discriminant analysis a ...	2011	21239132
structure of the effector-binding domain of the lysr-type transcription factor rovm from yersinia pseudotuberculosis.	in enteropathogenic yersinia, the expression of several early-phase virulence factors such as invasin is tightly regulated in response to environmental cues. the responsible regulatory network is complex, involving several regulatory rnas and proteins such as the lysr-type transcription regulator (lttr) rovm. in this study, the crystal structure of the effector-binding domain (ebd) of rovm, the first lttr protein described as being involved in virulence regulation, was determined at a resolution ...	2011	21245528
biofilm development on caenorhabditis elegans by yersinia is facilitated by quorum sensing-dependent repression of type iii secretion.	yersinia pseudotuberculosis forms biofilms on caenorhabditis elegans which block nematode feeding. this genetically amenable host-pathogen model has important implications for biofilm development on living, motile surfaces. here we show that y. pseudotuberculosis biofilm development on c. elegans is governed by n-acylhomoserine lactone (ahl)-mediated quorum sensing (qs) since (i) ahls are produced in nematode associated biofilms and (ii) y. pseudotuberculosis strains expressing an ahl-degrading ...	2011	21253572
the ail gene is present in some yersinia enterocolitica biotype 1a strains.	one chromosomal virulence marker of yersinia is the gene ail, which encodes ail, an outer membrane protein that promotes attachment and invasion. a high correlation has been found between the ail gene and the virulence of yersinia. here, we report two yersinia enterocolitica biotype 1a strains that are usually nonpathogenic and carry the ail gene. the ail gene sequences of biotype 1a strains displayed similarity to the bioserotype 1b/o:8 strain 8081. the finding suggests that ail-based detection ...	2011	21254915
activity modulation of the bacterial rho gap yope: an inspiration for the investigation of mammalian rho gaps.	the yersinia enterocolitica rho gtpase activating protein (rho gap) yope belongs to a group of bacterial virulence factors that is translocated into infected target cells by a type three secretion system. structurally and biochemically yope resembles eukaryotic rho gaps which control various cellular functions by modulating the activity of rho gtp binding proteins. here we summarise the published information on cellular effects, rho protein substrates, compartmentalisation and turnover of yope. ...	2011	21255863
yersinia enterocolitica outer protein t (yopt).	pathogenic yersinia strains evade the innate immune responses of the host by producing effector proteins (yersinia outer proteins (yops)), which are directly injected into mammalian cells by a type iii secretion system (ttss). one of these effector proteins (yopt) disrupts the actin cytoskeleton of the host cell. yopt is a cysteine protease which cleaves rho proteins directly upstream of the post-translationally modified cysteine. thereby, it releases the gtpases from the membrane leading to the ...	2011	21255864
[the prevalence of yersinia infection in adult patients with acute right lower quadrant pain].	clinical manifestations of intestinal yersiniosis include enterocolitis, mesenteric adenitis, and terminal ileitis presenting with fever, right lower quadrant pain, and leukocytosis. according to a previous korean study in 1997, yersinia was revealed in two among 15 adult patients with mesenteric adenitis (13%). however, recent reports on the prevalence of yersinia infection in adult patients are few. the aim of this study was to investigate the prevalence of yersinia infection in adult patients ...	2011	21258196
mice carrying a knock-in mutation of aicda resulting in a defect in somatic hypermutation have impaired gut homeostasis and compromised mucosal defense.	to elucidate the specific role of somatic hypermutation (shm) in mucosal immunity, we generated mice carrying a knock-in point mutation in aicda, which encodes activation-induced cytidine deaminase (aid), an enzyme essential to shm and class-switch recombination (csr). these mutant aid(g23s) mice had much less shm but had normal amounts of immunoglobulin in both serum and intestinal secretions. aid(g23s) mice developed hyperplasia of germinal center b cells in gut-associated lymphoid tissues, ac ...	2011	21258321
chemical composition and antimicrobial activity of the essential oils of anthospermum emirnense and anthospermum perrieri (rubiaceae).	the essential oils of anthospermum emirnense baker and anthospermum perrieri homolle ex puff, obtained by hydrodistillation in 0.03 and 0.02% yield, respectively, were analyzed by gc/ms. in both cases, the major constituents consisted of sesquiterpene hydrocarbons and oxygenated sesquiterpenes. the two species showed an important qualitative similarity, with 40 compounds common to a. emirnense and a. perrieri, including β-elemene, trans-β-caryophyllene, caryophyllene oxide, and τ-cadinol, which ...	2011	21259425
characterization of the rcsc sensor kinase from erwinia amylovora and other enterobacteria.	rcsc is a hybrid sensor kinase which contains a sensor domain, a histidine kinase domain, and a receiver domain. we have previously demonstrated that, although the erwinia amylovora rcsc mutant produces more amylovoran than the wild-type (wt) strain in vitro, the mutant remains nonpathogenic on both immature pear fruit and apple plants. in this study, we have comparatively characterized the erwinia rcsc and its homologs from various enterobacteria. results demonstrate that expression of the erwi ...	2011	21261468
yersinia enterocolitica bacteremia in a chronic, mildly iron-overloaded dialysis patient (february).	objective: to report an unusual case of yersinia enterocolitica in a chronic, mildly iron-overloaded dialysis patient lacking other typical risk factors for bacteremia, who was treated successfully with a third-generation cephalosporin as monotherapy for a short duration of treatment. case summary: a 76-year-old dialysis-dependent man developed y. enterocolitica bacteremia after 8 days of hospitalization. one month prior to presentation, his ferritin level was mildly elevated at 571.5 ng/ml, whi ...	2011	21266629
involvement of cd8+ t cell-mediated immune responses in lcrv dna vaccine induced protection against lethal yersinia pestis challenge.	yersinia pestis (y. pestis) is the causative pathogen of plague, a highly fatal disease for which an effective vaccine, especially against mucosal transmission, is still not available. like many bacterial infections, antigen-specific antibody responses have been traditionally considered critical, if not solely responsible, for vaccine-induced protection against y. pestis. studies in recent years have suggested the importance of t cell immune responses against y. pestis infection but information ...	2011	21199697
yopk regulates the yersinia pestis type iii secretion system from within host cells.	the pathogenic yersinia species share a conserved type iii secretion system, which delivers cytotoxic effectors known as yops into target mammalian cells. in all three species, yopk (also called yopq) plays an important role in regulating this process. in cell culture infections, yopk mutants inject higher levels of yops, leading to increase cytotoxicity; however, in vivo the same mutants are highly attenuated. in this work, we investigate the mechanism behind this paradox. using a β-lactamase r ...	2011	21205017
outbreak of gastroenteritis caused by yersinia pestis in afghanistan.	plague, which is most often caused by the bite of yersinia pestis-infected fleas, is a rapidly progressing, serious disease that can be fatal without prompt antibiotic treatment. in late december 2007, an outbreak of acute gastroenteritis occurred in nimroz province of southern afghanistan. of the 83 probable cases of illness, 17 died (case fatality 20·5%). being a case was associated with consumption or handling of camel meat (adjusted odds ratio 4·4, 95% confidence interval 2·2-8·8, p<0·001). ...	2011	20663260
sampling port for real-time analysis of bioaerosol in whole body exposure system for animal aerosol model development.	multiple factors influence the viability of aerosolized bacteria. the delivery of aerosols is affected by chamber conditions (humidity, temperature, and pressure) and bioaerosol characteristics (particle number, particle size distribution, and viable aerosol concentration). measurement of viable aerosol concentration and particle size is essential to optimize viability and lung delivery. the madison chamber is widely used to expose small animals to infectious aerosols.	2011	20849964
VALIDATION OF QUANTITATIVE ELISAs FOR MEASURING ANTI-YERSINIA PESTIS F1 AND V ANTIBODY CONCENTRATIONS IN NONHUMAN PRIMATE SERA.	This study systematically validated two quantitative enzyme-linked immunosorbent assays (ELISAs) for determining Yersinia pestis anti-F1 or anti-V IgG concentration in cynomolgus macaque sera. The results demonstrated that these ELISAs are reliable, reproducible, and suitable for their intended use to measure both anti-F1 and anti-V IgG in monkey sera following vaccination with a heterologous recombinant fusion F1-V protein (rF1-V). Statistical analysis demonstrated assay precision, accuracy, sp ...	2012	22181824
innate immunity in the small intestine.	purpose of review: this article reviews the most recent publications on innate immunity in the small intestine. we will go over the innate immune receptors that act as sensors of microbial presence or cell injury, paneth cells as the main epithelial cell type that secrete antimicrobial peptides, and mucosal production of immunoglobulin a (iga). in addition, we will give an update on examples of imbalance of the innate immune response resulting in clinical disease with the most relevant example b ...	2012	22241076
the patient presenting with acute dysentery - a systematic review.	objectives: the etiologies, clinical presentations and diagnosis of acute pathogen-specific dysentery in children and adults in industrialized and developing regions is described to help develop recommendations for therapy. methods: we conducted a systematic review of literature published between january 2000 and june 2011 to determine the frequency of occurrence of pathogen-specific dysentery. results: shigella, salmonella, and campylobacter remain the most frequent bacterial causes of dysenter ...	2012	22266388
Transmission of flea-borne zoonotic agents (*).	Flea-borne zoonoses such as plague (Yersinia pestis) and murine typhus (Rickettsia typhi) caused significant numbers of human cases in the past and remain a public health concern. Other flea-borne human pathogens have emerged recently (e.g., Bartonella henselae, Rickettsia felis), and their mechanisms of transmission and impact on human health are not fully understood. Our review focuses on the ecology and epidemiology of the flea-borne bacterial zoonoses mentioned above with an emphasis on rece ...	2012	21888520
nlrc4 inflammasomes in dendritic cells regulate noncognate effector function by memory cd8(+) t cells.	memory t cells exert antigen-independent effector functions, but how these responses are regulated is unclear. we discovered an in vivo link between flagellin-induced nlrc4 inflammasome activation in splenic dendritic cells (dcs) and host protective interferon-γ (ifn-γ) secretion by noncognate memory cd8(+) t cells, which could be activated by salmonella enterica serovar typhimurium, yersinia pseudotuberculosis and pseudomonas aeruginosa. we show that cd8α(+) dcs were particularly efficient at s ...	2012	22231517
structure of the yersinia pestis fabv enoyl-acp reductase and its interaction with two 2-pyridone inhibitors.	the recently discovered fabv enoyl-acp reductase, which catalyzes the last step of the bacterial fatty acid biosynthesis (fas-ii) pathway, is a promising but unexploited drug target against the reemerging pathogen yersinia pestis. the structure of y. pestis fabv in complex with its cofactor reveals that the enzyme features the common architecture of the short-chain dehydrogenase reductase superfamily, but contains additional structural elements that are mostly folded around the usually flexible ...	2012	22244758
polymorphisms in the lcrv gene of yersinia enterocolitica and their effect on plague protective immunity.	current efforts to develop plague vaccines focus on lcrv, a polypeptide that resides at the tip of type iii secretion needles. lcrv-specific antibodies block yersinia pestis type iii injection of yop effectors into host immune cells, thereby enabling phagocytes to kill the invading pathogen. earlier work reported that antibodies against y. pestis lcrv cannot block type iii injection by yersinia enterocolitica strains and suggested that lcrv polymorphisms may provide for escape from lcrv-mediated ...	2012	22252870
label-free detection of a bacterial pathogen using an immobilized siderophore, deferoxamine.	pathogenic bacteria obtain the iron necessary for survival by releasing an iron chelator, termed a siderophore, and retrieving the iron-siderophore complex via a cell surface siderophore receptor. we have exploited the high affinity of yersinia enterocolitica for its siderophore, deferoxamine, to develop a rapid method for capture and identification of yersinia. in this methodology, a deferoxamine-bovine serum albumin conjugate is printed onto a gold-plated chip in a parallel line pattern. after ...	2012	22274807
Identification of Yersinia ruckeri from diseased salmonid fish by Fourier transform infrared spectroscopy.	Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM), which mainly affects salmonid fish. Isolates of Y. ruckeri from diseased salmonid fish were obtained over a 6-year period from eight fish farms in the State of Baden-Württemberg, Southwest Germany. The strains were characterized by biochemical methods and Fourier transform infrared spectroscopy (FT-IR) combined with artificial neural network analysis. These methods were complemented by 16S rDNA sequencing for several isol ...	2012	22103737
the outer membrane protein a (ompa) of yersinia pestis promotes intracellular survival and virulence in mice.	the plague bacterium yersinia pestis has a number of well-described strategies to protect itself from both host cells and soluble factors. in an effort to identify additional anti-host factors, we employed a transposon site hybridization (trash)-based approach to screen 10(5)y. pestis mutants in an in vitro infection system. in addition to loci encoding various components of the well-characterized type iii secretion system (t3ss), our screen unambiguously identified ompa as a pro-survival gene. ...	2012	22023991
Application of nanoparticles for the detection and sorting of pathogenic bacteria by flow-cytometry.	In this paper we will describe a new developed contribution of fluorescence nano-crystal (q-dots) as a fluorescence label for detecting pathogenic bacteria by flow cytometry (FCM) and the use of nano-magnetic particles to improve bacterial sorting by Flow cytometry cell sorting (FACS).FCM or FACS systems are based upon single cell detection by light scatter and Immunofluorescence labeling signals. The common FACS systems are based upon single or dual excitation as excitation source both for ligh ...	2012	22101709
Mitogen-Activated Protein Kinase-Dependent Interleukin-1a Intracrine Signaling Is Modulated by YopP during Yersinia enterocolitica Infection.	Yersinia enterocolitica is a food-borne pathogen that preferentially infects the Peyer's patches and mesenteric lymph nodes, causing an acute inflammatory reaction. Even though Y. enterocolitica induces a robust inflammatory response during infection, the bacterium has evolved a number of virulence factors to limit the extent of this response. We previously demonstrated that interleukin-1a (IL-1a) was critical for the induction of gut inflammation characteristic of Y. enterocolitica infection. M ...	2012	22083707
a protective epitope in type iii effector yope is a major cd8 t cell antigen during primary infection with yersinia pseudotuberculosis.	virulence in human-pathogenic yersinia species is associated with a plasmid-encoded type iii secretion system that translocates a set of yop effector proteins into host cells. one effector, yope, functions as a rho gtpase-activating protein (gap). in addition to acting as a virulence factor, yope can function as a protective antigen. c57bl/6 mice infected with attenuated yersinia pestis generate a dominant h2-k(b)-restricted cd8 t cell response to an epitope in the n-terminal domain of yope (yop ...	2012	22064714
lack of antimicrobial resistance in yersinia pestis isolates from 17 countries in the americas, africa, and asia.	yersinia pestis is the causative agent of plague, a fulminant disease that is often fatal without antimicrobial treatment. plasmid (inca/c)-mediated multidrug resistance in y. pestis was reported in 1995 in madagascar and has generated considerable public health concern, most recently because of the identification of inca/c multidrug-resistant plasmids in other zoonotic pathogens. here, we demonstrate no resistance in 392 y. pestis isolates from 17 countries to eight antimicrobials used for trea ...	2012	22024826
A proteome reference map and virulence factors analysis of Yersinia pestis 91001.	In this report, we carried out the in-depth proteomic analysis of Yersinia pestis strain 91001 under in vitro flea-simulated condition using three technique routes, SDS-PAGE combined with LTQ-FT, two-dimensional liquid chromatography peptide (2D-LC peptide) separation combined with LTQ-FT and intact protein separation followed by 2D-LC peptide separation combined with LTQ-FT. Totally, 1926 proteins (13082 peptides) were identified, covering 46.50% (1926/4142) of the predicted proteome. Transcrip ...	2012	22040741
Identification of three oligo-/polysaccharide-specific ligases in Yersinia enterocolitica.	In lipopolysaccharide (LPS) biosynthesis of Gram-negative bacteria the lipid A-core oligosaccharide (LA-core) and O-polysaccharide (O-PS) biosynthesis pathways proceed separately and converge in periplasmic space where the waaL-encoded ligase joins O-PS onto LA-core. Enterobacterial common antigen (ECA) biosynthesis follows that of O-PS except that ECA is usually ligated to phosphatidylglycerol (PG) and only rarely to LA-core. In Yersinia enterocolitica serotype O:3 LPS is composed of LA-inner c ...	2012	22053911
Conserved Structural Mechanisms for Autoinhibition in IpaH Ubiquitin Ligases.	The IpaH family of novel E3 ligase (NEL) enzymes occur in a variety of pathogenic and commensal bacteria that interact with eukaryotic hosts. We demonstrate that the leucine-rich repeat (LRR) substrate recognition domains of different IpaH enzymes autoinhibit the enzymatic activity of the adjacent catalytic novel E3 ligase domain by two distinct but conserved structural mechanisms. Autoinhibition is required for the in vivo biological activity of two IpaH enzymes in a eukaryotic model system. Au ...	2012	22065585
differential immune response of rainbow trout (oncorhynchus mykiss) at early developmental stages (larvae and fry) against the bacterial pathogen yersinia ruckeri.	innate immune factors play a crucial role in survival of young fish especially during early stages of life when adaptive immunity is not fully developed. in the present study, we investigated the immune response of rainbow trout (oncorhynchus mykiss) larvae and fry at an early stage of development. we exposed 17 and 87° days post hatch larvae and fry (152 and 1118 degree days post hatch; avg. wt. 70 and 770 mg, respectively) to the bacterial pathogen, yersinia ruckeri for 4h by bath challenge. s ...	2012	21945730
expression, purification, structural and functional analysis of sycb: a type three secretion chaperone from yersinia enterocolitica.	in yersinia enterocolitica biovar 1b, a genome encoded ttss designated as ysa-ysp system is used for virulence. sycb is an annotated chaperone to this system. sycb is soluble in presence of translocator yspc. sycb and its truncated form (∆sycb((1-114))) exist as dimers. yspc forms a 1:1 complex with sycb. homology model of sycb shows a flexible n-terminal may be required for solubility and dimerization; and concave core formed by antiparallel helices of tprs. far uv cd spectra confirm that sycb ...	2012	22170450
microchip capillary electrophoresis of multi-locus vntr analysis for genotyping of bacillus anthracis and yersinia pestis in microbial forensic cases.	bacillus anthracis and yersinia pestis are etiological agents of anthrax and plague respectively, and are also considered among the most feared potential bioterrorism agents. these microorganisms show intraspecies genome homogeneity, making strains differentiation difficult, while strains identification and comparison with known genotypes may be crucial for naturally occurring outbreaks vs. bioterrorist events discrimination.here an mlva application for b. anthracis and y. pestis strains differe ...	2012	22139674
shotgun genome sequence of a yersinia enterocolitica isolate from the philippines.	the first shotgun genome sequence of a microbial pathogen from the philippines is reported. yersinia enterocolitica subsp. palearctica strain phrbd_ye1 is the first y. enterocolitica strain sequenced from an animal source, swine, which is a natural source of yersiniosis. the closest phylogenetic match is a human clinical isolate from germany.	2012	22207747
in vitro antimicrobial studies of silver carbene complexes: activity of free and nanoparticle carbene formulations against clinical isolates of pathogenic bacteria.	silver carbenes may represent novel, broad-spectrum antimicrobial agents that have low toxicity while providing varying chemistry for targeted applications. here, the bactericidal activity of four silver carbene complexes (sccs) with different formulations, including nanoparticles (nps) and micelles, was tested against a panel of clinical strains of bacteria and fungi that are the causative agents of many skin and soft tissue, respiratory, wound, blood, and nosocomial infections.	2012	21972270
Advanced Development of the rF1V and rBV A/B Vaccines: Progress and Challenges.	The development of vaccines for microorganisms and bacterial toxins with the potential to be used as biowarfare and bioterrorism agents is an important component of the US biodefense program. DVC is developing two vaccines, one against inhalational exposure to botulinum neurotoxins A1 and B1 and a second for Yersinia pestis, with the ultimate goal of licensure by the FDA under the Animal Rule. Progress has been made in all technical areas, including manufacturing, nonclinical, and clinical devel ...	2012	22028978
Simultaneous Detection of Six Diarrhea-Causing Bacterial Pathogens with an In-House PCR-Luminex Assay.	Diarrhea can be caused by a range of pathogens, including several bacteria. Conventional diagnostic methods, such as culture, biochemical tests, and enzyme-linked immunosorbent assay (ELISA), are laborious. We developed a 7-plex PCR-Luminex assay to simultaneously screen for several of the major diarrhea-causing bacteria directly in fecal specimens, including pathogenic Aeromonas, Campylobacter jejuni, Campylobacter coli, Salmonella, Shigella, enteroinvasive Escherichia coli (EIEC), Vibrio, and ...	2012	22075596
early systemic bacterial dissemination and a rapid innate immune response characterize genetic resistance to plague of seg mice.	background. although laboratory mice are usually highly susceptible to yersinia pestis, we recently identified a mouse strain (seg) that exhibited an exceptional capacity to resist bubonic plague and used it to identify immune mechanisms associated with resistance. methods. the kinetics of infection, circulating blood cells, granulopoiesis, lesions, and cellular populations in the spleen, and cytokine production in various tissues were compared in seg and susceptible c57bl/6j mice after subcutan ...	2012	22090450
pasteurization of milk: the heat inactivation kinetics of milk-borne dairy pathogens under commercial-type conditions of turbulent flow.	this is the first study to report kinetic data on the survival of a range of significant milk-borne pathogens under commercial-type pasteurization conditions. the most heat-resistant strain of each of the milk-borne pathogens staphylococcus aureus, yersinia enterocolitica, pathogenic escherichia coli, cronobacter sakazakii (formerly known as enterobacter sakazakii), listeria monocytogenes, and salmonella was selected to obtain the worst-case scenario in heat inactivation trials using a pilot-pla ...	2012	22192181
haemophilia-associated yersinia pseudotuberculosis serotype o:1 septicaemia: the role of iron.	septicaemia and septic arthritis due to yersinia pseudotuberculosis are rare diseases with high mortality rates. reactive arthritis caused by yersinia infection is a well-known complication but septic arthritis is found at a much lower frequency. it has already been established that there is a relationship between yersiniosis and iron but there are currently no data about yersiniosis and haematological disorders such as haemophilia. we report a case of septic arthritis due to y. pseudotuberculos ...	2012	22184209