Micronuclei frequency in medical workers occupationaly exposed to ionizing radiation

Jedan od najpogodnijih testova za biodozimetriju u akcidentima, ispitivanje genotoksičnosti i radiosenzitivnosti je cytochalazin-B mikronucleus test zbog svoje jednostavnosti, osetljivosti i relativno niske cene. Cilj rada je da utvdi da li profesionalna izloženost jonizujućem zračenju indukuje povećanje broja mikronukleusa. Istraživanjem je obuhvaćeno 77 medicinskih radnika, podeljenih na kontrolnu grupu (K) koju je činilo 33 ispitanika koji nisu izloženi JZ, I 44 ispitanika izloženih JZ (E), podeljene na dve podgrupe: eksponirane x-zračenju, (Ex) i eksponirane gama zračenju (En). Uzeti su podaci o načinu ishrane, navikama, zdravstvenom stanju. Grupe se nisu značajno razlikovale po polnoj distribuciji (p= 0.72), starosti (p= 0.76), navikama u ishrani, konzumiranju alkohola (p=0.16), pušenju (p=0.73) i ekspozicionom radnom stažu (p=0.93). Ispitanici obe grupe pregledani su u skladu sa Odlukom o stručnoj spremi i zdravstvenim uslovima ljudi koja rade sa izvorima jonizujućih zračenja (Sl. list SRJ 45/97). U laboratoriji za citogenetiku INN »Vinča« urañen je mikronukleus test.po modifikovanoj metodi Fenech-a i Morley-a. Doza zračenja procenjena je na osnovu rezultata lične dozimetrije sprovedene kalibrisanim ličnim termoluminiscentnim dozimetrima (TLD) tipa CaF2:Mn. Arterijska hipertenzija i katarakta su oboljenja značajno veće učestalosti u eksponiranih. Spontana učestalost MN značajno je veća u profesionalno izloženih lica (31±10/1000BN) u odnosu na kontrolnu grupu (17±8/1000BN)(p= 0.000). Učestalost MN nešto je veća u žena, ali je razlika značajna samo izmeñu muškaraca grupa K i E (p=0.0001), kao I žena (p=0.0002). Povišena učestalost hromozomskih aberacija nije bila značajno povezana sa brojem mikronukleusa, iako je tvrñena j značajnu zavisnost učestalosti mikronukleusa od doza (p=0.00022) i trajanjem ekspozicionog radnog staža (p=0.0000). Pretpostavili smo to može biti posledica razlika u DNK reparativnim procesima i/ili antioksidativnoj odbrani, kao i apoptoznoj aktivnosti.One of the most suitable tests for accidental biodosimetry, examining genotoxicity and radio sensitivity is cytochalazin-B micronucleus test because of its simplicity, sensitivity and low price comparing with other cytogenetic tests. The aim of this study is to investigate if occupational radiation exposures induce higher micronuclei score. Investigation comprised 77 medical workers on their routine yearly medical exam, 44 occupationally exposed to ionizing radiation (E), divided in two subgroupsexposed to x-rays (Ex) or gamma rays (En) and 33 controls (K). Informed consent and questionnaire containing dietary, habits, medical factors and exposure history were taken. Groups were matched in gender (p= 0.72538), age (p= 0.76839), habits - dietary, alcohol consumption (p=0.1653), smoking (p=0.738) and specific exposure time (p=0.9367). Radiation dose accumulated by occupationally exposed over years was calculated on the basis of individual TL-dose records and multiplied with exposure time. Micronuclei analysis was carried out on cultures of phytohaemaglutininstimulated blood lymphocytes (Wellcome, 2.4 µg/ml). Peripheral blood samples (0.5 ml) were cultured in 5ml RPMI-1640 medium suplemented with 15% calf serum at 37°C. At t= 44 h Cytohalazin B was added at a final concentracion of 6 µg/ml to induce binuclear cell formation. At t=72 h, cells were spun down, the medium removed and the cells were washed using Henk′ s basic salt solution. The cells were fixed in methanol: acetic acid (3:1) after 5min of mild hypotonic treatement ( 0.56% KCl + 0.9% NaCl in equal volumes). Slides were air-dried and stained in akaline Giemsa (2%). Slides for each donor were coded and duplicates of 1000 binucleated cells were examined for micronuclei by same experienced cytogenetics. Criteria set by Countyman and Heddle (LIT) and Fenech and Morley (LIT) were applied for micronuclei identification. The average frequency of micronuclei was significantly increased in occupationally exposed 31±10/1000BN versus controls 17±8/1000BN (p= 0.000). There was statistically significantly higher micronuclei incidence increased in men (p=0.0001) and women (p=0.0002) of exposed versus the same gender controls. Micronuclei score was not highly correlated with chromosomal aberration score, even it was highly correlated with doses (p=0.00022) and specific exposure time (p=0.0000). We supposed it could be the consequence of DNA-repair, antioxidative defense and apoptotic activity.XXII Simpozijum Jugoslovenskog društva za zaštitu od zračenja, Petrovac, Sep 29 - Okt 1, 2003

Influence of Temperature and Humidity on the Efficacy of Spinosad Against Four Stored-Grain Beetle Species

In the present work, we examined the insecticidal effect of spinosad, against adults of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) on wheat and the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae) on maize. The dose rates used were 0.01, 0.1, 0.5 and 1 ppm. The bioassays were carried out at three temperatures, 20, 25 and 30°C and two relative humidity levels, 55 and 75%. Mortality of R. dominica and S. oryzae was high even at 0.01 ppm of spinosad, reaching 100% at 55% relative humidity and 30° after 21 days of exposure. Generally, mortality of R. dominica, increased with temperature while for S. oryzae mortality increased with temperature and with the decrease of relative humidity. Moreover, for S. oryzae, mortality was low at 20°C. In the case of T. confusum, mortality was low at doses between 0.01 and 0.5 ppm even after 21 days of exposure. At 1 ppm, mortality exceeded 90% only at 30°C and only after 21 days of exposure. Mortality of P. truncatus was low on maize treated with 0.01 ppm, but increasing the dose to 0.1 ppm resulted in > 87% mortality after 14 days of exposure. In several combinations tested, spinosad efficacy notably varied according to the temperature and humidity regimes. Of the species tested, R. dominica and P. truncatus were very susceptible to spinosad, followed by S. oryzae, while T. confusum was the least susceptible

Genetic and morphological variation in sexual and asexual parasitoids of the genus Lysiphlebus - an apparent link between wing shape and reproductive mode

Background: Morphological divergence often increases with phylogenetic distance, thus making morphology taxonomically informative. However, transitions to asexual reproduction may complicate this relationship because asexual lineages capture and freeze parts of the phenotypic variation of the sexual populations from which they derive. Parasitoid wasps belonging to the genus Lysiphlebus Foerster (Hymenoptera: Braconidae: Aphidiinae) are composed of over 20 species that exploit over a hundred species of aphid hosts, including many important agricultural pests. Within Lysiphlebus, two genetically and morphologically well- defined species groups are recognised: the "fabarum" and the "testaceipes" groups. Yet within each group, sexual as well as asexual lineages occur, and in L. fabarum different morphs of unknown origin and status have been recognised. In this study, we selected a broad sample of specimens from the genus Lysiphlebus to explore the relationship between genetic divergence, reproductive mode and morphological variation in wing size and shape (quantified by geometric morphometrics). Results: The analyses of mitochondrial and nuclear gene sequences revealed a clear separation between the "testaceipes" and "fabarum" groups of Lysiphlebus, as well as three well-defined phylogenetic lineages within the "fabarum" species group and two lineages within the "testaceipes" group. Divergence in wing shape was concordant with the deep split between the "testaceipes" and "fabarum" species groups, but within groups no clear association between genetic divergence and wing shape variation was observed. On the other hand, we found significant and consistent differences in the shape of the wing between sexual and asexual lineages, even when they were closely related. Conclusions: Mapping wing shape data onto an independently derived molecular phylogeny of Lysiphlebus revealed an association between genetic and morphological divergence only for the deepest phylogenetic split. In more recently diverged taxa, much of the variation in wing shape was explained by differences between sexual and asexual lineages, suggesting a mechanistic link between wing shape and reproductive mode in these parasitoid wasps

Detection of Borrelia-specific 16S rRNA sequence in total RNA extracted from Ixodes ricinus ticks

A reverse transcriptase - polymerase chain reaction based assay for Borrelia species detection in ticks was developed. The method was based on amplification of 552 nucleotide bases long sequence of 16S rRNA, targeted by Borrelia specific primers. In the present study, total RNA extracted from Ixodes ricinus ticks was used as template. The results showed higher sensitivity for Borrelia detection as compared to standard dark-field microscopy. Method specificity was confirmed by cloning and sequencing of obtained 552 base pairs long amplicons. Phylogenetic analysis of obtained sequences showed that they belong to B. lusitaniae and B. afzelii genospecies. RT-PCR based method presented in this paper could be very useful as a screening test for detecting pathogen presence, especially when in investigations is required extraction of total RNA from ticks

Contributions to the phylogeny of Ixodes (Pholeoixodes) canisuga, I. (Ph.) kaiseri, I. (Ph.) hexagonus and a simple pictorial key for the identification of their females

Background: In Europe, hard ticks of the subgenus Pholeoixodes (Ixodidae: Ixodes) are usually associated with burrow-dwelling mammals and terrestrial birds. Reports of Pholeoixodes spp. from carnivores are frequently contradictory, and their identification is not based on key diagnostic characters. Therefore, the aims of the present study were to identify ticks collected from dogs, foxes and badgers in several European countries, and to reassess their systematic status with molecular analyses using two mitochondrial markers. Results: Between 2003 and 2017, 144 Pholeoixodes spp. ticks were collected in nine European countries. From accurate descriptions and comparison with type-materials, a simple illustrated identification key was compiled for adult females, by focusing on the shape of the anterior surface of basis capituli. Based on this key, 71 female ticks were identified as I. canisuga, 21 as I. kaiseri and 21 as I. hexagonus. DNA was extracted from these 113 female ticks, and from further 31 specimens. Fragments of two mitochondrial genes, cox1 (cytochrome c oxidase subunit 1) and 16S rRNA, were amplified and sequenced. Ixodes kaiseri had nine unique cox1 haplotypes, which showed 99.2-100% sequence identity, whereas I. canisuga and I. hexagonus had eleven and five cox1 haplotypes, respectively, with 99.5-100% sequence identity. The distribution of cox1 haplotypes reflected a geographical pattern. Pholeoixodes spp. ticks had fewer 16S rRNA haplotypes, with a lower degree of intraspecific divergence (99.5-100% sequence identity) and no geographical clustering. Phylogenetic analyses were in agreement with morphology: I. kaiseri and I. hexagonus (with the similar shape of the anterior surface of basis capituli) were genetically more closely related to each other than to I. canisuga. Phylogenetic analyses also showed that the subgenus Eschatocephalus (bat ticks) clustered within the subgenus Pholeoixodes. Conclusions: A simple, illustrated identification key is provided for female Pholeoixodes ticks of carnivores (including I. hexagonus and I. rugicollis) to prevent future misidentification of these species. It is also shown that I. kaiseri is more widespread in Europe than previously thought. Phylogenetic analyses suggest that the subgenus Pholeoixodes is not monophyletic: either the subgenus Eschatocephalus should be included in Pholeoixodes, or the latter subgenus should be divided, which is a task for future studies

Occurrence and identification of risk areas of Ixodes ricinus-borne pathogens: a cost-effectiveness analysis in north-eastern Italy

<p>Abstract</p> <p>Background</p> <p><it>Ixodes ricinus</it>, a competent vector of several pathogens, is the tick species most frequently reported to bite humans in Europe. The majority of human cases of Lyme borreliosis (LB) and tick-borne encephalitis (TBE) occur in the north-eastern region of Italy. The aims of this study were to detect the occurrence of endemic and emergent pathogens in north-eastern Italy using adult tick screening, and to identify areas at risk of pathogen transmission. Based on our results, different strategies for tick collection and pathogen screening and their relative costs were evaluated and discussed.</p> <p>Methods</p> <p>From 2006 to 2008 adult ticks were collected in 31 sites and molecularly screened for the detection of pathogens previously reported in the same area (i.e., LB agents, TBE virus, <it>Anaplasma phagocytophilum, Rickettsia </it>spp., <it>Babesia </it>spp., "<it>Candidatus Neoehrlichia mikurensis</it>"). Based on the results of this survey, three sampling strategies were evaluated <it>a</it>-<it>posteriori</it>, and the impact of each strategy on the final results and the overall cost reductions were analyzed. The strategies were as follows: tick collection throughout the year and testing of female ticks only (strategy A); collection from April to June and testing of all adult ticks (strategy B); collection from April to June and testing of female ticks only (strategy C).</p> <p>Results</p> <p>Eleven pathogens were detected in 77 out of 193 ticks collected in 14 sites. The most common microorganisms detected were <it>Borrelia burgdorferi </it>sensu lato (17.6%), <it>Rickettsia helvetica </it>(13.1%), and "<it>Ca. N. mikurensis</it>" (10.5%). Within the <it>B. burgdorferi </it>complex, four genotypes (i.e., <it>B. valaisiana, B. garinii, B. afzelii</it>, and <it>B. burgdorferi </it>sensu stricto) were found. Less prevalent pathogens included <it>R. monacensis </it>(3.7%), TBE virus (2.1%), <it>A. phagocytophilum </it>(1.5%), <it>Bartonella </it>spp. (1%), and <it>Babesia </it>EU1 (0.5%). Co-infections by more than one pathogen were diagnosed in 22% of infected ticks. The prevalences of infection assessed using the three alternative strategies were in accordance with the initial results, with 13, 11, and 10 out of 14 sites showing occurrence of at least one pathogen, respectively. The strategies A, B, and C proposed herein would allow to reduce the original costs of sampling and laboratory analyses by one third, half, and two thirds, respectively. Strategy B was demonstrated to represent the most cost-effective choice, offering a substantial reduction of costs, as well as reliable results.</p> <p>Conclusions</p> <p>Monitoring of tick-borne diseases is expensive, particularly in areas where several zoonotic pathogens co-occur. Cost-effectiveness studies can support the choice of the best monitoring strategy, which should take into account the ecology of the area under investigation, as well as the available budget.</p

The Effects of Aphid Traits on Parasitoid Host Use and Specialist Advantage

Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and hostuse efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susceptibility to parasitoid attack. To address this question, we used data from a 13-year survey of interactions among 142 aphid and 75 parasitoid species in nine European countries. We found that only aphid traits related to local resource characteristics seem to influence the trade-off between host-range and efficiency: more specialized parasitoids had an apparent advantage (higher abundance on shared hosts) on aphids with sparse colonies, ant-attendance and without concealment, and this was more evident when host relatedness was included in calculation of parasitoid specificity. More traits influenced average assemblage specialization, which was highest in aphids that are monophagous, monoecious, large, highly mobile (easily drop from a plant), without myrmecophily, habitat specialists, inhabit non-agricultural habitats and have sparse colonies. Differences in aphid wax production did not influence parasitoid host specificity and host-use. Our study is the first step in identifying host traits important for aphid parasitoid host specificity and host-use and improves our understanding of bottom-up effects of aphid traits on aphid-parasitoid food web structure

Diversity and Distribution of Braconidae, a Family of Parasitoid Wasps in the Central European Peatbogs of South Bohemia, Czech Republic

An ecological overview of seven years investigation of Braconidae, a family of parasitoid wasps (Hymenoptera: Ichneumonoidea) and a tyrpho-classification of parasitoids in peatbog areas of South Bohemia, Czech Republic are given. A total of 350 species were recorded in investigated sites, but only five tyrphobionts (1.4%) are proposed: Microchelonus basalis, Microchelonus koponeni, Coloneura ate, Coloneura danica and Myiocephalus niger. All of these species have a boreal-alpine distribution that, in Central Europe, is associated only with peatbogs. Tyrphophilous behaviour is seen in at least four (1.1%) species: Microchelonus pedator, Microchelonus subpedator, Microchelonus karadagi and Microchelonus gravenhorstii; however, a number of other braconids prefer peatbogs because they were more frequently encountered within, rather than outside, the bog habitat. The rest of the braconids (342 species, 97.5%) are tyrphoneutrals, many of them being eurytopic components of various habitats throughout their current ranges. Lists of tyrphobiontic braconids and a brief commentary on species composition, distributional picture of actual ranges, and parasitoid association to bog landscape are provided. Being true refugial habitats for populations in an ever-changing world, peatbogs play a significant role in harboring insect communities

Dermacentor reticulatus: a vector on the rise

Dermacentor reticulatus is a hard tick species with extraordinary biological features. It has a high reproduction rate, a rapid developmental cycle, and is also able to overcome years of unfavourable conditions. Dermacentor reticulatus can survive under water for several months and is cold-hardy even compared to other tick species. It has a wide host range: over 60 different wild and domesticated hosts are known for the three active developmental stages. Its high adaptiveness gives an edge to this tick species as shown by new data on the emergence and establishment of D. reticulatus populations throughout Europe. The tick has been the research focus of a growing number of scientists, physicians and veterinarians. Within the Web of Science database, more than a fifth of the over 700 items published on this species between 1897 and 2015 appeared in the last three years (2013–2015). Here we attempt to synthesize current knowledge on the systematics, ecology, geographical distribution and recent spread of the species and to highlight the great spectrum of possible veterinary and public health threats it poses. Canine babesiosis caused by Babesia canis is a severe leading canine vector-borne disease in many endemic areas. Although less frequently than Ixodes ricinus, D. reticulatus adults bite humans and transmit several Rickettsia spp., Omsk haemorrhagic fever virus or Tick-borne encephalitis virus. We have not solely collected and reviewed the latest and fundamental scientific papers available in primary databases but also widened our scope to books, theses, conference papers and specialists colleagues’ experience where needed. Besides the dominant literature available in English, we also tried to access scientific literature in German, Russian and eastern European languages as well. We hope to inspire future research projects that are necessary to understand the basic life-cycle and ecology of this vector in order to understand and prevent disease threats. We conclude that although great strides have been made in our knowledge of the eco-epidemiology of this species, several gaps still need to be filled with basic research, targeting possible reservoir and vector roles and the key factors resulting in the observed geographical spread of D. reticulatus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1599-x) contains supplementary material, which is available to authorized users