Food safety and zoonotic enteric pathogens: sources, risk factors and transmission routes of human salmonellosis and campylobacteriosis

Salmonella and Campylobacter are common causes of human gastroenteritis. Their epidemiology is complex and a multi-tiered approach to control is needed, taking into account the different reservoirs, pathways and risk factors. In this thesis, trends in human gastroenteritis and food-borne outbreak notifications in Italy were explored. Moreover, the improved sensitivity of two recently-implemented regional surveillance systems in Lombardy and Piedmont was evidenced, providing a basis for improving notification at the national level. Trends in human Salmonella serovars were explored: serovars Enteritidis and Infantis decreased, Typhimurium remained stable and 4,[5],12:i:-, Derby and Napoli increased, suggesting that sources of infection have changed over time. Attribution analysis identified pigs as the main source of human salmonellosis in Italy, accounting for 43–60% of infections, followed by Gallus gallus (18–34%). Attributions to pigs and Gallus gallus showed increasing and decreasing trends, respectively. Potential bias and sampling issues related to the use of non-local/non-recent multilocus sequence typing (MLST) data in Campylobacter jejuni/coli source attribution using the Asymmetric Island (AI) model were investigated. As MLST data become increasingly dissimilar with increasing geographical/temporal distance, attributions to sources not sampled close to human cases can be underestimated. A combined case-control and source attribution analysis was developed to investigate risk factors for human Campylobacter jejuni/coli infection of chicken, ruminant, environmental, pet and exotic origin in The Netherlands. Most infections (~87%) were attributed to chicken and cattle. Individuals infected from different reservoirs had different associated risk factors: chicken consumption increased the risk for chicken-attributed infections; animal contact, barbecuing, tripe consumption, and never/seldom chicken consumption increased that for ruminant-attributed infections; game consumption and attending swimming pools increased that for environment-attributed infections; and dog ownership increased that for environment- and pet-attributed infections. Person-to-person contacts around holiday periods were risk factors for infections with exotic strains, putatively introduced by returning travellers.

Mediterranean-type climate in the South Aegean (Eastern Mediterranean) during the Late Miocene: Evidence from isotope and element proxies

The present-day climate in the Mediterranean region is characterized by mild, wet winters and hot, dry summers. There is contradictory evidence as to whether the present-day conditions (“Mediterranean climate”) already existed in the Late Miocene. This thesis presents seasonally-resolved isotope and element proxy data obtained from Late Miocene reef corals from Crete (Southern Aegean, Eastern Mediterranean) in order to illustrate climate conditions in the Mediterranean region during this time. There was a transition from greenhouse to icehouse conditions without a Greenland ice sheet during the Late Miocene. Since the Greenland ice sheet is predicted to melt fully within the next millennia, Late Miocene climate mechanisms can be considered as useful analogues in evaluating models of Northern Hemispheric climate conditions in the future. So far, high resolution chemical proxy data on Late Miocene environments are limited. In order to enlarge the proxy database for this time span, coral genus Tarbellastraea was evaluated as a new proxy archive, and proved reliable based on consistent oxygen isotope records of Tarbellastraea and the established paleoenvironmental archive of coral genus Porites. In combination with lithostratigraphic data, global 87Sr/86Sr seawater chronostratigraphy was used to constrain the numerical age of the coral sites, assuming the Mediterranean Sea to be equilibrated with global open ocean water. 87Sr/86Sr ratios of Tarbellastraea and Porites from eight stratigraphically different sampling sites were measured by thermal ionization mass spectrometry. The ratios range from 0.708900 to 0.708958 corresponding to ages of 10 to 7 Ma (Tortonian to Early Messinian). Spectral analyses of multi-decadal time-series yield interannual δ18O variability with periods of ~2 and ~5 years, similar to that of modern records, indicating that pressure field systems comparable to those controlling the seasonality of present-day Mediterranean climate existed, at least intermittently, already during the Late Miocene. In addition to sea surface temperature (SST), δ18O composition of coral aragonite is controlled by other parameters such as local seawater composition which as a result of precipitation and evaporation, influences sea surface salinity (SSS). The Sr/Ca ratio is considered to be independent of salinity, and was used, therefore, as an additional proxy to estimate seasonality in SST. Major and trace element concentrations in coral aragonite determined by laser ablation inductively coupled plasma mass spectrometry yield significant variations along a transect perpendicular to coral growth increments, and record varying environmental conditions. The comparison between the average SST seasonality of 7°C and 9°C, derived from average annual δ18O (1.1‰) and Sr/Ca (0.579 mmol/mol) amplitudes, respectively, indicates that the δ18O-derived SST seasonality is biased by seawater composition, reducing the δ18O amplitude by 0.3‰. This value is equivalent to a seasonal SSS variation of 1‰, as observed under present-day Aegean Sea conditions. Concentration patterns of non-lattice bound major and trace elements, related to trapped particles within the coral skeleton, reflect seasonal input of suspended load into the reef environment. δ18O, Sr/Ca and non-lattice bound element proxy records, as well as geochemical compositions of the trapped particles, provide evidence for intense precipitation in the Eastern Mediterranean during winters. Winter rain caused freshwater discharge and transport of weathering products from the hinterland into the reef environment. There is a trend in coral δ18O data to more positive mean δ18O values (–2.7‰ to –1.7‰) coupled with decreased seasonal δ18O amplitudes (1.1‰ to 0.7‰) from 10 to 7 Ma. This relationship is most easily explained in terms of more positive summer δ18O. Since coral diversity and annual growth rates indicate more or less constant average SST for the Mediterranean from the Tortonian to the Early Messinian, more positive mean and summer δ18O indicate increasing aridity during the Late Miocene, and more pronounced during summers. The analytical results implicate that winter rainfall and summer drought, the main characteristics of the present-day Mediterranean climate, were already present in the Mediterranean region during the Late Miocene. Some models have argued that the Mediterranean climate did not exist in this region prior to the Pliocene. However, the data presented here show that conditions comparable to those of the present-day existed either intermittently or permanently since at least about 10 Ma.

The Effect of Metronome Pacing on Gait in Healthy Subjects

The complex process of gait is rendered partially automatic by central pattern generators (CPGs). To further our understanding of their role in gait control in healthy subjects, we applied a paradigm of anti-phase, or syncopated, movement to gait. To provide a context for our results, we reviewed the literature on in-phase, or synchronized, gait. The review results are as follows. Auditory cueing increased step/stride rate for older subjects, but not younger. Stride rate variability decreased for younger subjects, perhaps because the metronome’s cue acted as a temporal ‘anchor point’ for each step. Step width increased in half of the treadmill studies, but none of the overground ones, suggesting a cumulative effect of the attentional demands of synchronizing gait while on a treadmill. Time series analysis revealed that the α exponent was the most sensitive parameter reported, decreasing toward anti-persistence in almost all cued-gait studies. This project compares in-phase (IN) and anti-phase gait (ANTI) in young and old healthy subjects. We expected gait to be less disrupted during ANTI trials at preferred speed, when the facilitating effect of CPGs would be strongest. The measures step time variability, jerk index, and harmonic ratio quantified gait perturbation: none indicated that ANTI was easiest at preferred walking speed. Surprisingly, the gait of older subjects was no more perturbed than that of younger subjects. When they successfully matched the pace of the beat, they unwittingly synchronized to it. The temporal relationship of their steps to the beat was the same in the IN and ANTI conditions. Younger subjects, visibly struggling during ANTI trials, were able to walk in syncopation. This result suggests that cognitive resources available only to the younger group are required to resist synchronizing to the beat.

Expressionsunterschiede verschiedener miRNAs bei chronisch-entzündlichen Darmerkrankungen

Chronisch-entzündliche Darmerkrankungen konfrontieren unsere heutige Gesellschaft mit hohen Inzidenzraten in der westlichen Welt und zunehmend steigenden Inzidenzraten im asiatischen Raum. Die Folgen für die Patienten sind eine starke Beeinträchtigung der Lebensqualität, mit sozialen und wirtschaftlichen Folgen sowie ein erhöhtes Risiko für die Entwicklung kolorektaler Karzinome. Durch die Entdeckung von 22 nt langen, regulierenden RNAs, auch genannt miRNAs, wurde ein neuer Baustein im Verständnis zellulärer Regelprozesse und der Differenzierung und Aktivierung von Antworten etwa des Immunsystems entdeckt. Somit stellt sich die Frage nach der Bedeutung von miRNAs im Rahmen von chronisch-entzündlichen Darmerkrankungen. Hierzu wurden in dieser Arbeit über ein miRNA-Array System 12 miRNAs als potentiell relevante Ziele identifiziert und an einem Kollektiv aus insgesamt 131 Patienten und 163 Biopsien aus dem Bereich des Darmes überprüft. Es zeigte sich hierbei, dass im Rahmen eines Morbus Crohn mit Befall des Dickdarms die miRNAs let-7d und miR-22 in gesteigerter Expression vorlagen. Da im terminalen Ileum eine gesonderte Immunsituation vorliegt, wurde dieser Bereich zusätzlich bei der Erkrankung Morbus Crohn untersucht. Es zeigten sich Expressionsveränderungen für die miRNAs miR-30e, miR-185, miR-374b und miR-424. Bei Patienten mit einer Colitis ulcerosa waren die miRNAs let-7d, miR-185 und miR-424 in ihrem Expressionsverhalten verändert. Zusätzlich konnte gezeigt werden, dass in Abhängigkeit vom Entzündungsgrad bei bestehender Colitis ulcerosa eine zunehmenden Überexpression der miRNAs let-7d, miR-185 und miR-424 erfolgte. Die miRNAs miR-18a und miR-185 wiesen unter Remissionsbedingungen Expressionsveränderungen auf und lassen somit den Verdacht eines protektiven Effektes aufkommen. Mit Hilfe von computerbasierten Datenbankanalysen konnten gemeinsam regulierenden miRNAs Proteine und Pathways zugeordnet werden, welche einen Zusammenhang mit bereits pathogenetisch bestätigten Signalwegen wie etwa dem nF-ĸB und MAPK-Signalweg nahelegen. Auch konnte herausgearbeitet werden, dass einige, der von diesen miRNAs regulierten Proteine, bereits in veröffentlichten Arbeiten als fehlreguliert festgestellt wurden, jedoch blieb die Ursache dieser Fehlregulation gänzlich unbekannt. Mit den in dieser Arbeit erhobenen Daten konnte gezeigt werden, dass eine Kongruenz der Befunde vorliegt, welche einen Zusammenhang der miRNA-Expression mit der Fehlregulation bestimmter Proteine nicht nur nahelegt, sondern darüber hinaus auch noch einige weitere potentielle Proteinziele für weitere Untersuchungen aufführt. Dazu ist es jedoch notwendig, die Relevanz der hier entdeckten, computerbasierten Proteine in zukünftigen Untersuchungen einer genauen Prüfung zu unterziehen.

Applicazione del metodo "Alpha" per la stima della massima risposta torsionale in strutture asimmetriche in pianta

Il seguente elaborato ha lo scopo di analizzare il comportamento torsionale di diverse tipologie strutturali, valutare la veridicità del metodo “Alpha” per strutture ad un piano e successivamente testare la validità del metodo per strutture multipiano. Nel primo capitolo è stato introdotto inizialmente il problema, poi sono stati definiti per il sistema oggetto di studio l’equazione del moto e i diversi parametri che intervengono. Tra questi parametri di rilevante importanza si hanno l’indice di torsioflessibilità e l’eccentricità. Infine è stato definito il metodo “Alpha” per la determinazione della massima risposta rotazionale. Nel secondo capitolo è stata eseguita una valutazione analitica del parametro di torsioflessibilità per il caso specifico di struttura con due setti disposti ad uguale distanza dal centro di massa sia per il caso di struttura a pianta quadrata che per quella a pianta rettangolare. Nel terzo e nel quarto capitolo è stata effettuata una valutazione dell’indice di torsioflessibilità e dell’eccentricità, sia per strutture a pianta quadrata che per strutture a pianta rettangolare, caratterizzate da diversi elementi resistenti disposti in differenti posizioni. In particolare è stato analizzato come cambia l’indice di torsioflessibilità al variare dell’eccentricità per una stessa struttura. Nel quinto e sesto capitolo sono riportati i risultati delle analisi modali condotte per tutti i casi visti nei capitoli precedenti: nel caso ad un piano e nel caso di strutture multipiano (cinque e dieci piani). Nel settimo e ottavo capitolo sono riportati i risultati delle analisi time-history eseguite per le stesse strutture, dalle quali sono stati determinati gli spostamenti al fine di eseguire una verifica del metodo per strutture ad un piano e studiare i risultati ottenuti per strutture multipiano. Il lavoro svolto si conclude con il nono capitolo in cui sono stati riportati i risultati e le conclusioni.

Insertion of Dissipative Devices in Precast RC Structures

Viscous dampers are characterized as very effective devices applied for seismic design and retrofitting. The objective of this thesis is to apply the Five-Step Procedure ,developed by a research group in University of Bologna, for sizing the viscous dampers to be installed in an existing precast RC structure. The idea is to apply the viscous damping devices in different positions in the structure then to identify and compare the performance of all types placement position.

Analisi statica equivalente per strutture dotate di smorzatori viscosi

L’installazione di smorzatori viscosi sulle strutture permette di dissipare l’energia che il sisma trasmette, senza provocare danni o rotture degli elementi strutturali principali. Questi dispositivi sono stati l'oggetto di numerosi lavori di ricerca dal 1980 fino ad oggi e l'efficacia nel mitigare gli effetti dell’azione sismica su strutture edilizie è stata ampiamente dimostrata. La maggior parte delle teorie scientifiche per la progettazione e l'ottimizzazione degli smorzatori si basano sofisticati algoritmi, portando talvolta a complessi procedure. L'applicazione di tali algoritmi richiede spesso competenze computazionali e di tempo eccessive. Il fine della tesi è quello di proporre un metodo pratico, cioè diretto e immediato per aiutare gli ingegneri per effettuare analisi sismiche su strutture intelaiate dotate di smorzatori viscosi e di dimensionare tali dispositivi. Tale metodo è stato l’oggetto del lavoro di ricerca scientifica trattato nell’articolo: “Equivalent Static Analyses of framed structures with added viscous dampers” di Palermo et al., 2015. Si riesce così ad estendere così il concetto di analisi statica equivalente anche per strutture dotate di smorzatori viscosi, definendo in maniera intuitiva sia le configurazioni di idealizzazione della strutture durante il sisma sia l’ idealizzazione dell’effetto del sisma sulla struttura. In questi anni di lavoro di ricerca, sono stati proposti vari metodi per il dimensionamento degli smorzatori viscosi. Tra questi, il prof. Ing. Silvestri (Silvestri et al., 2010) ha proposto un approccio progettuale diretto, chiamato "five step procedure” che mira a guidare l'ingegnere professionista, dalla scelta del target di prestazioni alle identificazioni della caratteristiche meccaniche di smorzatori viscosi trovabili in commercio. La procedura originale (Silvestri et al., 2010, Silvestri et al., 2011, Palermo et al., 2013), anche se per lo più basata su espressioni analitiche, richiede ancora lo sviluppo di analisi numeriche Time-History di modelli FEM, al fine di valutare le forze massime negli smorzatori aggiunti. Verrà spiegato e proposto un metodo semplificato (“Direct five step procedure for the dimensioning of added viscous dampers” Palermo et al., 2015) che consente ottenere direttamente, tramite una semplice formula, le forze massime degli smorzatori (spesso un parametro chiave della valutazione del costo degli smorzatori), senza eseguire simulazioni numeriche. Infine, si è applicato il metodo semplificato proposto di analisi statica equivalente per strutture equipaggiate di smorzatori viscosi ad un edificio reale.

Investigation of petabyte-scale data transfer performances with PhEDEx for the CMS experiment

PhEDEx, the CMS transfer management system, during the first LHC Run has moved about 150 PB and currently it is moving about 2.5 PB of data per week over the Worldwide LHC Computing Grid (WLGC). It was designed to complete each transfer required by users at the expense of the waiting time necessary for its completion. For this reason, after several years of operations, data regarding transfer latencies has been collected and stored into log files containing useful analyzable informations. Then, starting from the analysis of several typical CMS transfer workflows, a categorization of such latencies has been made with a focus on the different factors that contribute to the transfer completion time. The analysis presented in this thesis will provide the necessary information for equipping PhEDEx in the future with a set of new tools in order to proactively identify and fix any latency issues. PhEDEx, il sistema di gestione dei trasferimenti di CMS, durante il primo Run di LHC ha trasferito all’incirca 150 PB ed attualmente trasferisce circa 2.5 PB di dati alla settimana attraverso la Worldwide LHC Computing Grid (WLCG). Questo sistema è stato progettato per completare ogni trasferimento richiesto dall’utente a spese del tempo necessario per il suo completamento. Dopo svariati anni di operazioni con tale strumento, sono stati raccolti dati relativi alle latenze di trasferimento ed immagazzinati in log files contenenti informazioni utili per l’analisi. A questo punto, partendo dall’analisi di una ampia mole di trasferimenti in CMS, è stata effettuata una suddivisione di queste latenze ponendo particolare attenzione nei confronti dei fattori che contribuiscono al tempo di completamento del trasferimento. L’analisi presentata in questa tesi permetterà di equipaggiare PhEDEx con un insieme di utili strumenti in modo tale da identificare proattivamente queste latenze e adottare le opportune tattiche per minimizzare l’impatto sugli utenti finali.

Inserimento di controventi dissipativi in acciaio in un capannone in calcestruzzo armato prefabbricato a due piani

In questa tesi si propone il miglioramento sismico di un capannone in calcestruzzo armato prefabbricato a due piani a pilastri isostatici mediante l'inserimento di controventi dissipativi in acciaio con forma speciale (Crescent-Shaped-Braces). PREMESSA In primo luogo si dimostra come la struttura studiata soddisfi già i requisiti del DM 2008, sia allo SLD (spostamenti d’ interpiano) che allo SLV (elementi strutturali verificati). OBIETTIVO Migliorare le caratteristiche prestazionali di un edificio in calcestruzzo armato prefabbricato a due piani, sottoposto ad azione sismica. STRATEGIA Inserimento di dispositivi dissipativi di tipo Crescent Shaped Brace in alcune specchiature del capannone prefabbricato, in entrambe le direzioni. PROGETTAZIONE DELLA STRUTTURA RINFORZATA 1) Identificazione delle caratteristiche (rigidezza e resistenza) dei dispositivi CSB, sulla base di obiettivi scalati al livello superiore (deformabilità allo SLV e resistenza allo SLC) per il sistema «struttura + dispositivi», attraverso lo sviluppo di una procedura specifica per capannoni prefabbricati a 2 piani. 2) Progettazione dei dispositivi CSB (scelta della geometria e della sezione) 3) Verifica delle effettive prestazioni ottenute mediante simulazioni numeriche time-history

Analyzing spatio-temporal patterns of genuine cross-correlations

In multivariate time series analysis, the equal-time cross-correlation is a classic and computationally efficient measure for quantifying linear interrelations between data channels. When the cross-correlation coefficient is estimated using a finite amount of data points, its non-random part may be strongly contaminated by a sizable random contribution, such that no reliable conclusion can be drawn about genuine mutual interdependencies. The random correlations are determined by the signals' frequency content and the amount of data points used. Here, we introduce adjusted correlation matrices that can be employed to disentangle random from non-random contributions to each matrix element independently of the signal frequencies. Extending our previous work these matrices allow analyzing spatial patterns of genuine cross-correlation in multivariate data regardless of confounding influences. The performance is illustrated by example of model systems with known interdependence patterns. Finally, we apply the methods to electroencephalographic (EEG) data with epileptic seizure activity.

Macrophages and dendritic cells express tight junction proteins and exchange particles in an in vitro model of the human airway wall

The human airway epithelium serves as structural and functional barrier against inhaled particulate antigen. Previously, we demonstrated in an in vitro epithelial barrier model that monocyte derived dendritic cells (MDDC) and monocyte derived macrophages (MDM) take up particulate antigen by building a trans-epithelial interacting network. Although the epithelial tight junction (TJ) belt was penetrated by processes of MDDC and MDM, the integrity of the epithelium was not affected. These results brought up two main questions: (1) Do MDM and MDDC exchange particles? (2) Are those cells expressing TJ proteins, which are believed to interact with the TJ belt of the epithelium to preserve the epithelial integrity? The expression of TJ and adherens junction (AJ) mRNA and proteins in MDM and MDDC monocultures was determined by RT-PCR, and immunofluorescence, respectively. Particle uptake and exchange was quantified by flow cytometry and laser scanning microscopy in co-cultures of MDM and MDDC exposed to polystyrene particles (1 μm in diameter). MDM and MDDC constantly expressed TJ and AJ mRNA and proteins. Flow cytometry analysis of MDM and MDDC co-cultures showed increased particle uptake in MDDC while MDM lost particles over time. Quantitative analysis revealed significantly higher particle uptake by MDDC in co-cultures of epithelial cells with MDM and MDDC present, compared to co-cultures containing only epithelial cells and MDDC. We conclude from these findings that MDM and MDDC express TJ and AJ proteins which could help to preserve the epithelial integrity during particle uptake and exchange across the lung epithelium.

Optical properties of a nanomatch-like plasmonic structure

The optical properties of a match-like plasmonic nanostructure are numerically investigated using full-wave finite-difference time-domain analysis in conjunction with dispersive material models. This work is mainly motivated by the developed technique enabling reproducible fabrication of nanomatch structures as well as the growing applications that utilize the localized field enhancement in plasmonic nanostructures. Our research revealed that due to the pronounced field enhancement and larger resonance tunabilities, some nanomatch topologies show potentials for various applications in the field of, e.g., sensing as well as a novel scheme for highly reproducible tips in scanning near field optical microscopy, among others. Despite the additional degrees of freedom that are offered by the composite nature of the proposed nanomatch topology, the paper also reflects on a fundamental complication intrinsic to the material interfaces especially in the nanoscale: stoichiometric mixing. We conclude that the specificity in material modeling will become a significant issue in future research on functionalized composite nanostructures.

Rivaroxaban: Quantification by anti-FXa assay and influence on coagulation tests A study in 9 Swiss laboratories

INTRODUCTION: Rivaroxaban (RXA) is licensed for prophylaxis of venous thromboembolism after major orthopaedic surgery of the lower limbs. Currently, no test to quantify RXA in plasma has been validated in an inter-laboratory setting. Our study had three aims: to assess i) the feasibility of RXA quantification with a commercial anti-FXa assay, ii) its accuracy and precision in an inter-laboratory setting, and iii) the influence of 10mg of RXA on routine coagulation tests. METHODS: The same chromogenic anti-FXa assay (Hyphen BioMed) was used in all participating laboratories. RXA calibrators and sets of blinded probes (aim ii.) were prepared in vitro by spiking normal plasma. The precise RXA content was assessed by high-pressure liquid chromatography-tandem mass spectrometry. For ex-vivo studies (aim iii), plasma samples from 20 healthy volunteers taken before and 2 - 3hours after ingestion of 10mg of RXA were analyzed by participating laboratories. RESULTS: RXA can be assayed chromogenically. Among the participating laboratories, the mean accuracy and the mean coefficient of variation for precision of RXA quantification were 7.0% and 8.8%, respectively. Mean RXA concentration was 114±43?g/L .RXA significantly altered prothrombin time, activated partial thromboplastin time, factor analysis for intrinsic and extrinsic factors. Determinations of thrombin time, fibrinogen, FXIII and D-Dimer levels were not affected. CONCLUSIONS: RXA plasma levels can be quantified accurately and precisely by a chromogenic anti-FXa assay on different coagulometers in different laboratories. Ingestion of 10mg RXA results in significant alterations of both PT- and aPTT-based coagulation assays.

Dorsal rather than ventral visual pathways discriminate freezing status in Parkinson's disease

BACKGROUND: Although visuospatial deficits have been linked with freezing of gait (FOG) in Parkinson's disease (PD), the specific effects of dorsal and ventral visual pathway dysfunction on FOG is not well understood. METHOD: We assessed visuospatial function in FOG using an angle discrimination test (dorsal visual pathway bias) and overlapping figure test (ventral visual pathway bias), and recorded overall response time, mean fixation duration and dwell time. Covariate analysis was conducted controlling for disease duration, motor severity, contrast sensitivity and attention with Bonferroni adjustments for multiple comparisons. RESULTS: Twenty seven people with FOG, 27 people without FOG and 24 controls were assessed. Average fixation duration during angle discrimination distinguished freezing status: [F (1, 43) = 4.77 p < 0.05] (1-way ANCOVA). CONCLUSION: Results indicate a preferential dysfunction of dorsal occipito-parietal pathways in FOG, independent of disease severity, attentional deficit, and contrast sensitivity.

Alpine ibex (Capra i. ibex) is not a reservoir for chlamydial infections of domestic ruminants and humans

Chlamydophila (C.) abortus is the most common infectious abortigenic agent in small domestic ruminants in Switzerland. In contrast, the knowledge about chlamydiae in wild ruminants is scarce. As interactions between livestock and Alpine ibex (Capra i. ibex) occur on alpine pastures, the question raises if wild ruminants could play a role as carriers of chlamydiae. Thus, we investigated the prevalence of chlamydiae in Alpine ibex in Switzerland. In total, 624 sera, 676 eye swabs, 84 organ samples and 51 faecal samples from 664 ibex were investigated. Serum samples were tested by two commercial ELISA kits specific for C. abortus. Eye swabs, organs and faecal samples were examined by a Chlamydiaceae-specific real-time polymerase chain reaction (PCR). Positive cases were further investigated by the ArrayTube (AT) microarray method for chlamydial species determination. Of 624 serum samples investigated, 612 animals were negative, whereas nine sera (1.5%) reacted positively in one of the two tests and three sera showed an inconclusive result. Eye swabs of seven out of 412 ibex (1.7%) were tested positive for Chlamydiaceae by real-time PCR. By AT microarray, Chlamydophila (C.) pecorum was identified in two animals, Chlamydophila (C.) pneumoniae was detected in one animal and a mixed infection with C. abortus and C. pecorum was found in four animals. Organs and faecal samples were all negative by real-time PCR analysis. In summary, we conclude that C. abortus is not a common infectious agent in the Swiss ibex population. To our knowledge, this is the first description of C. pneumoniae in ibex. Further studies are necessary to elucidate the situation in other species of wild ruminants as chamois (Rupicapra r. rupicapra), red deer (Cervus elaphus) and roe deer (Capreolus c. capreolus) in Switzerland.