Plasmid diversity and phylogenetic consistency in the Lyme disease agent Borrelia burgdorferi

Background: Bacteria from the genus Borrelia are known to harbor numerous linear and circular plasmids. We report here a comparative analysis of the nucleotide sequences of 236 plasmids present in fourteen independent isolates of the Lyme disease agent B. burgdorferi. Results: We have sequenced the genomes of 14 B. burgdorferi sensu stricto isolates that carry a total of 236 plasmids. These individual isolates carry between seven and 23 plasmids. Their chromosomes, the cp26 and cp32 circular plasmids, as well as the lp54 linear plasmid, are quite evolutionarily stable; however, the remaining plasmids have undergone numerous non-homologous and often duplicative recombination events. We identify 32 different putative plasmid compatibility types among the 236 plasmids, of which 15 are (usually) circular and 17 are linear. Because of past rearrangements, any given gene, even though it might be universally present in these isolates, is often found on different linear plasmid compatibility types in different isolates. For example, the arp gene and the vls cassette region are present on plasmids of four and five different compatibility types, respectively, in different isolates. A majority of the plasmid types have more than one organizationally different subtype, and the number of such variants ranges from one to eight among the 18 linear plasmid types. In spite of this substantial organizational diversity, the plasmids are not so variable that every isolate has a novel version of every plasmid (i.e., there appears to be a limited number of extant plasmid subtypes). Conclusions: Although there have been many past recombination events, both homologous and nonhomologous, among the plasmids, particular organizational variants of these plasmids correlate with particular chromosomal genotypes, suggesting that there has not been rapid horizontal transfer of whole linear plasmids among B. burgdorferi lineages. We argue that plasmid rearrangements are essentially non-revertable and are present at a frequency of only about 0.65% that of single nucleotide changes, making rearrangement-derived novel junctions (mosaic boundaries) ideal phylogenetic markers in the study of B. burgdorferi population structure and plasmid evolution and exchange

Irrigation water requirement of fruit trees in the Central, West and South Serbia on a district scale

A common problem of all fruit producers is establishing the optimal irrigation schedule (irrigation interval and amount of water) which would provide a highquality yield with efficient use of water, preservation of soils and the environment. In this study, Seasonal Irrigation Water Requirement (SIWR) was calculated from the difference between the crop evapotranspiration (ETc) and effective rainfall (Pe) for the fruit crops in the 13 districts of Central (CS), West (WS), and South Serbia (SS). Analysed fruit production averaging around 9.8% of total arable land area. Depending on the crop water requirements and grass cover (GC) fruits were separated into seven groups: apples, pears, plums, walnuts and hazels without GC (I) and with GC (II); apricots, peaches, nectarines without GC (III) and with GC (IV); sweet cherries, sour cherries without GC (V) and with GC (VI) and raspberries, blackberries, blueberries (VII). Reference evapotranspiration (ETo), Pe, ETc, and SIWR were calculated based on FAO-56 methodolgy using daily meteorological data (mean, maximum and minimum temperature ,extra-terrestrial radiation and rainfall) for the period 2000-2019 obtained from 13 meteorological stations. The average SIWR amounts to 349, 541, 153, 272, 123, 220, and 207 mm for all the seven groups; I, II, III, IV, V, VI, and VII, respectively. Spatially SIWR values ranged from 232.8, 366.5, 428.2 mm for WS, CS, and SS districts respectively. Depending on whether the orchard is grass-covered or not ETo changes significantly. Crop evapotranspiration is 26% higher in the GC orchards compared to the orchards without GC. Great differences in SIWR going from Western to Eastern parts of Serbia indicate that for good irrigation practices and efficient irrigation system design, it is necessary to adopt SIWR calculated on a district scale or even farm scale. Obtained results indicate that besides SIWR, selecting the proper agronomy practices and growing systems has a significant impact on obtaining high-quality yields while saving water and preserve soils

Building capacities for sustainable energy in municipalities of Western Balkans

This paper discusses challenges of capacity building in sustainable urban energy planning and development in Western Balkan Countries (WBC). It identifies needs in training of municipal staff and addresses obstacles for transferring sustainable energy education from EU universities to universities of WBC. The analysis of the ten training courses developed and piloted in collaboration with academic and non-academic stakeholders in Bosnia and Herzegovina, Montenegro and Serbia shows that while international cooperation has a good potential to improve quality of capacity building and to catalyse university-society collaboration in WBC, significant efforts on national and local (university) levels are needed to fully capitalise on these opportunities. In particular, it is necessary to enhance an interdisciplinary approach to education in sustainable energy, incorporating economic, social and institutional aspects of energy production and consumption together with the technical ones. On the national level, the lifelong learning system should get political and financial support in WBC to ensure efficiency and continuity of the training activities.Postprint (published version

Genome Stability of Lyme Disease Spirochetes: Comparative Genomics of Borrelia burgdorferi Plasmids

Lyme disease is the most common tick-borne human illness in North America. In order to understand the molecular pathogenesis, natural diversity, population structure and epizootic spread of the North American Lyme agent, Borrelia burgdorferi sensu stricto, a much better understanding of the natural diversity of its genome will be required. Towards this end we present a comparative analysis of the nucleotide sequences of the numerous plasmids of B. burgdorferi isolates B31, N40, JD1 and 297. These strains were chosen because they include the three most commonly studied laboratory strains, and because they represent different major genetic lineages and so are informative regarding the genetic diversity and evolution of this organism. A unique feature of Borrelia genomes is that they carry a large number of linear and circular plasmids, and this work shows that strains N40, JD1, 297 and B31 carry related but non-identical sets of 16, 20, 19 and 21 plasmids, respectively, that comprise 33–40% of their genomes. We deduce that there are at least 28 plasmid compatibility types among the four strains. The B. burgdorferi ∼900 Kbp linear chromosomes are evolutionarily exceptionally stable, except for a short ≤20 Kbp plasmid-like section at the right end. A few of the plasmids, including the linear lp54 and circular cp26, are also very stable. We show here that the other plasmids, especially the linear ones, are considerably more variable. Nearly all of the linear plasmids have undergone one or more substantial inter-plasmid rearrangements since their last common ancestor. In spite of these rearrangements and differences in plasmid contents, the overall gene complement of the different isolates has remained relatively constant

Progress in Adenoviral Capsid-Display Vaccines

Adenoviral vectored vaccines against infectious diseases are currently in clinical trials due to their capacity to induce potent antigen-specific B- and T-cell immune responses. Heterologous prime-boost vaccination with adenoviral vector and, for example, adjuvanted protein-based vaccines can further enhance antigen-specific immune responses. Although leading to potent immune responses, these heterologous prime-boost regimens may be complex and impact manufacturing costs limiting efficient implementation. Typically, adenoviral vectors are engineered to genetically encode a transgene in the E1 region and utilize the host cell machinery to express the encoded antigen and thereby induce immune responses. Similarly, adenoviral vectors can be engineered to display foreign immunogenic peptides on the capsid-surface by insertion of antigens in capsid proteins hexon, fiber and protein IX. The ability to use adenoviral vectors as antigen-display particles, with or without using the genetic vaccine function, greatly increases the versatility of the adenoviral vector for vaccine development. This review describes the application of adenoviral capsid antigen-display vaccine vectors by focusing on their distinct advantages and possible limitations in vaccine development

Progress in Adenoviral Capsid-Display Vaccines

Adenoviral vectored vaccines against infectious diseases are currently in clinical trials due to their capacity to induce potent antigen-specific B- and T-cell immune responses. Heterologous prime-boost vaccination with adenoviral vector and, for example, adjuvanted protein-based vaccines can further enhance antigen-specific immune responses. Although leading to potent immune responses, these heterologous prime-boost regimens may be complex and impact manufacturing costs limiting efficient implementation. Typically, adenoviral vectors are engineered to genetically encode a transgene in the E1 region and utilize the host cell machinery to express the encoded antigen and thereby induce immune responses. Similarly, adenoviral vectors can be engineered to display foreign immunogenic peptides on the capsid-surface by insertion of antigens in capsid proteins hexon, fiber and protein IX. The ability to use adenoviral vectors as antigen-display particles, with or without using the genetic vaccine function, greatly increases the versatility of the adenoviral vector for vaccine development. This review describes the application of adenoviral capsid antigen-display vaccine vectors by focusing on their distinct advantages and possible limitations in vaccine development

Assessment of AquaCrop model on potato water requirements in climate change conditions

Potato is the most important non-grain crop in the world. Produced in a traditional way (without irrigation) in Bosnia and Herzegovina averages about 370 000 tons per year. Climate change will probably affect potato crop production, especially due to shallow rooting system. The aim of this paper is to assess the impact of climate change on the potato water requirements for the IPCC RCP 8.5 scenario. AquaCrop V6.0 model was used to estimate potato irrigation norms (In), drainage water and yield. Three distinct area were analyzed; Banja Luka, Bijeljina and Mostar. Climate data were obtained from a climate change simulation of a regional climate model NMMB. The simulation is done as a dynamical downscaling of the global model CMCC-CM over the Southeast Europe. Models are forced with IPCC RCP8.5 scenario. Four periods were analyzed; the reference period (1971-2000) and three time slices in the future: 2020s (2011-2040); 2050s (2041-2070; 2080s (2071-2100). Obtained results in three future periods were compared with referenced ones, and shown as a relative ratio. Sowing dates will be moved towards winter months in all areas. Such results will have an impact on yield increment in rainfed conditions up to 85%. Obtained data showed decrement of the In in Banja Luka and Mostar area up to 18% and 25% through the century, respectively. However, drier conditions in Bjeljina region will affect yield decline. In increment with magnitude of 70% to 34% will be expected in Bjeljina area due to lower precipitation. Thus makes irrigation very important in order to achieve genetic potential of potato. Drainage system should be implemented and/or well maintained in all areas

Seasonal water requirements of maize in the region of Vojvodina

Global climate changes, which are characterized by an increase in temperature, reduction of precipitation, especially during the summer months, significantly affect the overall production of spring sowing crops. Maize is the predominant crop in Serbia. It is grown in about 1 million hectares with average yield about 7,9 t/ha. Precisely for that reason, in this paper, the analysis of water deficit on the maize fields in the region of Vojvodina was performed. The total used agricultural land of the surveyed area is about 1,574,365.71 ha, while the maize grown area occupies about 551,028 ha (35%). A series of meteorological data from the previous 20 years (2000 - 2019) from 7 meteorological stations of the Administrative Districts from the regions covered by the survey were used for the analysis. Evapotranspiration, crop evapotranspiration (maize), effective rainfall and water deficit were calculated using FAO-56 methodology. The amount of water consumed during the evapotranspiration process in the vegetation period averaging about 625.07 mm (from 597.4 mm in the North Bačka District to 646.8 mm in the West Bačka District). Maize has the greatest water requirement during the tasseling and silking phases, in July, when the largest water deficit is observed, which averages 152.51 mm (from 143.6 mm in the South Banat District to 159.2 mm in the Srem District). The seasonal water deficit averages 347.24 mm (from 310.8 mm in the area of South Bačka District to 369 mm in the area of West Bačka District). As the availability of water is a key factor for high and stable maize yields, this research aimed to examine the water requirements in the area where the maize represents more than half of the total production

Effect of irrigation regime on water use efficiency and qualitative properties of panonia grapes

The cultivation of plant cultures, in this case vines, largely depends on the climate, which directly affects the growth and development of grapes. The aim of this study is to determine the impact of different irrigation regimes on yield, water use efficiency (WUE), and grape quality parameters. The experiment was conducted in a vineyard growing a white varietal (cv. Panonia) at Plavinci, Serbia. During the experimental year (2021), temperatures were significantly higher and precipitation significantly below average during the phenophase of maturation, so irrigation was applied in three regimes as a percentage of crop evapotranspiration (ETc) during the vegetation period: full irrigated, F (100% ETc); deficit, D (50% ETc); and rainfed, R (0% ETc). The watering turn was 7 days, and the watering norm, ie. the amount of water given in one watering was 15 mm for D and 30 mm for F treatment. The obtained results indicate that the yields are significantly higher in irrigation treatments, ie. they range from: 12.776,04 kg•ha-1, 13.763,56 kg•ha-1 and 10.122,08 kg•ha-1 for F, D, R, respectively. Irrigation water use efficiency is 14,74 kg•ha-1•mm-1 and 40,46 kg•ha-1•mm-1 for IWUEF and IWUED. In the non-irrigated treatment, WUER is 39,53 kg•ha-1•mm-1. The sugar content in the wider by treatments is 22,4%, 22,8% and 21,1% for F, D, R, respectively. The content of total acids is 5,25 g/l, 6,15 g/l and 5,33 g/l, for F, D, R, respectively. The treatment of deficit irrigation shows the best results because it consumes water efficiently and has excellent grape quality

The prediction of grapevine phenophases in climate change conditions

Prediction of phenophases under future climate change scenarios is becoming a strategic tool for the adaptation to climate change. The aim of this research was to predict changes in the phenology of the grapevine variety (cv. Panonia) in the vineyard Plavinci (Serbia). Two future periods were analyzed: I (2021-2040); II (2041-2060) and compared with observed (2015-2021) and reference data (1986-2005). The scenario RCP 8.5 was selected to predict the future accompanied by a set of 8 regional climate models (RCMs) from the EUROCORDEX project database. The results indicated that for the period I the budburst could be expected on April 14th (3 days later), fl owering on May 29th (6 days later), veraison on July 25th (11 days later), harvest around September 8th (17 days later), and the end of vegetation around November 1st (1 week earlier) compared to the observed period. For the period II the date for the budburst, fl owering, veraison, ripe for harvest, and end of vegetation are predicted for April 8th (3 days earlier), May 24th (1 day later), July 18th (4 days later), August 28th (6 days later), and November 11th (4 days later), respectively. Signifi cant coincidences of the date of the beginning of phenophases for the observed period and the II period, while the period I indicates the later appearance of veraison (approximately 7 days). The harvest is expected about 10 days later in relation to these two periods. Comparing these three periods with the reference one, it can be concluded that in the past the vegetative period of the vine lasted shorter, the growing season began much later (April 18th) and ended earlier (October 28th), while the beginnings of other phenophases occurred later