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Smrdel K.S.,Institute of Microbiology and Immunology | Serdt M.,Institute of Microbiology and Immunology | Duh D.,Public Health Institute Maribor | Knap N.,Institute of Microbiology and Immunology | Zupanc T.A.,Institute of Microbiology and Immunology
Parasites and Vectors | Year: 2010

Ticks act as vectors of many pathogens of domestic animals and humans. Anaplasma phagocytophilum in Europe is transmitted by the ixodid tick vector Ixodes ricinus. A. phagocytophilum causes a disease with diverse clinical signs in various hosts. A great genetic diversity of the groESL operon of A. phagocytophilum has been found in ticks elsewhere. In Slovenia, the variety of the groESL operon was conducted only on deer samples. In this study, the prevalence of infected ticks was estimated and the diversity of A. phagocytophilum was evaluated. On 8 locations in Slovenia, 1924 and 5049 (6973) I. ricinus ticks were collected from vegetation in the years 2005 and 2006, respectively. All three feeding stages of the tick's life cycle were examined. The prevalence of ticks infected with A. phagocytophilum in the year 2005 and in the year 2006 was 0.31% and 0.63%, respectively, and it did not differ considerably between locations. The similarity among the sequences of groESL ranged from 95.6% to 99.8%. They clustered in two genetic lineages along with A. phagocytophilum from Slovenian deer. One sequence formed a separate cluster. According to our study, the prevalence of A. phagocytophilum in ticks is comparable to the findings in other studies in Europe, and it does not vary considerably between locations and tick stages. According to groESL operon analysis, two genetic lineages have been confirmed and one proposed. Further studies on other genes would be useful to obtain more information on genetic diversity of A. phagocytophilum in ticks in Slovenia. © 2010 Smrdel et al; licensee BioMed Central Ltd.

Durmisi E.,University of Ljubljana | Knap N.,University of Ljubljana | Saksida A.,University of Ljubljana | Trilar T.,Slovenian Museum of Natural History | And 2 more authors.
Vector-Borne and Zoonotic Diseases | Year: 2011

The hard tick Ixodes ricinus is the principal vector of tick-borne encephalitis virus (TBEV) in Slovenia; but until now, there was no information about the prevalence of TBEV infection in Slovenian ticks. We conducted a 2-year survey in 2005 and 2006, during which we were collecting I. ricinus ticks monthly in eight different locations of Slovenia. A total of 4777 I. ricinus ticks were collected: 1515 in year 2005 and 3262 in year 2006. The collected ticks were pooled into groups from which total RNA was extracted. Viral RNA was detected using real-time RT-polymerase chain reaction (PCR). Ticks infected with TBEV were found in six of eight locations. Viral RNA was detected in 8 of the 230 pools of ticks collected in 2005 and in 14 of the 442 pools collected in 2006. Prevalence of TBEV infection in Slovenian ticks was determined as 0.47%: 0.54% in 2005 and 0.43% in 2006. The detected infection rate in ticks significantly correlates with the TBEV incidence rates in selected areas. Using the method of sequencing, we have confirmed that the TBEV in ticks is genetically related to the TBEV in Slovenian patients. © Copyright 2011, Mary Ann Liebert, Inc.

Durjava M.K.,Public Health Institute Maribor | Kolar B.,Public Health Institute Maribor | Arnus L.,Public Health Institute Maribor | Papa E.,University of Insubria | And 4 more authors.
ATLA Alternatives to Laboratory Animals | Year: 2013

The environmental fate and effects of triazoles and benzotriazoles are of concern within the context of chemical regulation. As part of an intelligent testing strategy, experimental tests were performed on endpoints that are relevant for risk assessment. The experimental tests included the assessment of ecotoxicity to an alga, a daphnid and zebrafish embryos, and the assessment of ready biodegradability. Triazole and benzotriazole compounds were selected for testing, based on existing toxicity data for vertebrate and invertebrate species, as well as on the principal component analysis of molecular descriptors aimed at selecting the minimum number of test compounds in order to maximise the chemical domain spanned for both compound classes. The experimental results show that variation in the toxicities of triazoles and benzotriazole across species was relatively minor; in general, the largest factor was approximately 20. The study conducted indicated that triazoles are not readily biodegradable.

Cassani S.,University of Insubria | Kovarich S.,University of Insubria | Papa E.,University of Insubria | Roy P.P.,University of Insubria | And 13 more authors.
ATLA Alternatives to Laboratory Animals | Year: 2013

QSAR regression models of the toxicity of triazoles and benzotriazoles ([B]TAZs) to an alga (Pseudokirchneriella subcapitata), Daphnia magna and a fish (Onchorhynchus mykiss), were developed by five partners in the FP7-EU Project, CADASTER. The models were developed by different methods - Ordinary Least Squares (OLS), Partial Least Squares (PLS), Bayesian regularised regression and Associative Neural Network (ASNN) - by using various molecular descriptors (DRAGON, PaDEL-Descriptor and QSPRTHESAURUS web). In addition, different procedures were used for variable selection, validation and applicability domain inspection. The predictions of the models developed, as well as those obtained in a consensus approach by averaging the data predicted from each model, were compared with the results of experimental tests that were performed by two CADASTER partners. The individual and consensus models were able to correctly predict the toxicity classes of the chemicals tested in the CADASTER project, confirming the utility of the QSAR approach. The models were also used for the prediction of aquatic toxicity of over 300 (B)TAZs, many of which are included in the REACH pre-registration list, and were without experimental data. This highlights the importance of QSAR models for the screening and prioritisation of untested chemicals, in order to reduce and focus experimental testing.

Mansouri K.,University of Milan Bicocca | Consonni V.,University of Milan Bicocca | Durjava M.K.,Public Health Institute Maribor | Kolar B.,Public Health Institute Maribor | And 2 more authors.
Chemosphere | Year: 2012

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in textiles, foams and plastics. Highly bioaccumulative with toxic effects including developmental neurotoxicity estrogen and thyroid hormones disruption, they are considered as persistent organic pollutants (POPs) and have been found in human tissues, wildlife and biota worldwide. But only some of them are banned from EU market.For the environmental fate studies of these compounds the bioconcentration factor (BCF) is one of the most important endpoints to start with. We applied quantitative structure-activity relationships techniques to overcome the limited experimental data and avoid more animal testing.The aim of this work was to assess the bioaccumulation of PBDEs by means of QSAR. First, a BCF dataset of specifically conducted experiments was modeled. Then the study was extended by predicting the bioaccumulation and biomagnification factors using some experimental values from the literature. Molecular descriptors were calculated using DRAGON 6. The most relevant ones were selected and resulting models were compared paying attention to the applicability domain. © 2012 Elsevier Ltd.

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