Aleksandar Jurisic

Molecular detection of emerging tick-borne pathogens in Vojvodina, Serbia

Ticks play an important role in disease transmission globally due to their capability to serve as vectors for human and animal pathogens. The Republic of Serbia is an endemic area for a large number of tick-borne diseases. However, current knowledge on these diseases in Serbia is limited. The aim of this study was to investigate the presence of new emerging tick-borne pathogens in ticks collected from dogs and the vegetation from different parts of Vojvodina, Serbia. A total of 187 ticks, including 124 Rhipicephalus sanguineus, 45 Ixodes ricinus and 18 Dermacentor reticulatus were collected from dogs. In addition, 26 questing I. ricinus ticks were collected from the vegetation, using the flagging method, from 4 different localities in Vojvodina, Serbia. DNA was extracted from each tick individually and samples were tested by either conventional or real-time PCR assays for the presence of Rickettsia spp.-DNA (gltA and ompA gene fragments), Ehrlichia/Anaplasma spp.-DNA (16S rRNA gene fragment) and Hepatozoon spp./Babesia spp.-DNA (18S rRNA gene fragment). In addition, all I. ricinus DNA samples were tested for Bartonella spp.-DNA (ITS locus) by real-time PCR. In this study, the presence of novel emerging tick-borne pathogens including Rickettsia raoultii, Rickettsia massiliae, Babesia venatorum, Babesia microti, Hepatozoon canis and Candidatus Neoehrlichia mikurensis was identified for the first time in Serbia. Our findings also confirmed the presence of Rickettsia monacensis, Babesia canis and Anaplasma phagocytophilum in ticks from Serbia. The findings of the current study highlight the great diversity of tick-borne pathogens of human and animal importance in Serbia. Physicians, public health workers and veterinarians should increase alertness to the presence of these tick-borne pathogens in this country.

The application of lambda-cyhalothrin in tick control

In recent years, in urban areas of Novi Sad, unique ecological conditions, specific floristic and faunistic composition and poor habits of citizens in sense of public health, facilitate the development and maintenance of ticks. Regarding the importance of ticks as vectors of severe human and animal diseases, complex and detailed studies are conducted with an aim to find the most efficient methods for tick control. Two tick species, Ixodes ricinus and Dermacentor marginatus, were identified during a 3-year period on the territory of Municipality of Novi Sad. During 2006, the efficacy of the pyrethroid lambda-cyhalothrin in tick control varied from 60.7 to 100%. The highest efficacy recorded in 2007 was 92.3%. The efficacy of lambda-cyhalothrin in 2008 varied from 39.1 to 100%. Lambda-cyhalothrin showed high efficacy in tick control at localities which were improved before the application (mowed, litter removed, abundance control and euthanasia of abandoned cats and dogs). The results of this research indicate that lambda-cyhalothrin has a toxic effect on ticks and could be used as efficient acaricide for tick control, although its efficacy depends on formulation, terrain features and methods of application.

Molecular characterization of Borrelia strains isolated from ticks in Vojvodina

Borrelia burgdorferi sensu lato (s.l.) complex represents a group of different types of spirochete that are present globally, which causes Lyme borreliosis. The total number of types is still not final because new genetic and antigenic isolates are still being described. The clinical picture of Lyme borreliosis in people is polymorphic and is characterized with symptoms similar to flu syndromes together with erythema migrans, rheumatologic, cardiologic and neurological complications. Apart from people, dogs, horses, bovines and sheep can suffer from Lyme borreliosis. In Europe, the most important vector transmitting Lyme disease is the tick Ixodes ricinus. A description of different species of Borrelia in ticks has opened a completely new field of investigating the ecology of Lyme borreliosis. It is especially important to investigate a connection between different types of Borrelia, ticks as vectors and vertebrates as the reservoirs on various geographical localities. The aim of the work is to isolate Borrelia species from the collected ticks I. ricinus from the geographical territory of Vojvodina, and to do a molecular characterization of the isolated strains of Borrelia. A total of 12 tick pools of the type I. ricinus were cultivated in Barbour-Stoenner-Kelly-H medium with additional antibiotics and subcultivated into a modified Kelly-Pettenkofer/Preac-Mursic medium, until a clear culture is reached. For the molecular characterization of isolated strains of Borrelia, molecular methods MluI-LRFP and real-time PCR for hbb gene were used. In this research, out of 12 pools of ticks species I. ricinus 3 strains of Borrelia from the B. burgdorferi s.l. complex were isolated. All three isolates of Borrelia from ticks of the tick species I. ricinus from the territory of Vojvodina were identified as Borrelia afzelii by applying molecular methods (MluI-LRFP and real-time PCR for hbb gene). By applying MluI-LRFP all three isolated strains of B. afzelii were characterized as a subtype Mlal. In this research, like in the previous researches, we have not proved the presence of a pathogenic species Borrelia spielmanii in ticks of the species I. ricinus.

Seasonal distribution and species association among spider mites (Acari: Tetranychidae) and predatory mites (Acari: Phytoseiidae and Acari: Stigmaeidae) in Serbian apple orchards

ABSTRACT Species composition and population dynamics of spider mites (Panonychus ulmi (Acari: Tetranychidae) (Koch) and Tetranychus urticae Koch (Acari: Tetranychidae)) and predaceous mites (Amblyseius andersoni (Chant) (Acari: Phytoseiidae) and Zetzellia mali (Ewing) (Acari: Stigmaeidae)) were studied for eight months each year (March–October) during 2005–2007 at two localities with different intensities of pesticide use. Using Berger–Parkers dominance index and Sorensons coefficient, the index of dominance and predator–predator, predator–prey, and prey–prey associations were defined among each of these species to determine changes in species compositions and population densities and comprehend the influence of pesticide use in pest management on populations of spider and predatory mites in apple orchards. Sorensons coefficient helped to measure the intensity of positive, neutral, or negative interspecific associations for each species and Berger–Parkers dominance index clarified the dominance of specific species. During 2005 the dominant species in both localities was P. ulmi, but during 2006–2007 at one locality both species of spider mites showed almost equal dominance. The results of Sorensons coefficient confirmed that there was significant predator–prey association among P. ulmi and A. andersoni and P. ulmi and Z. mali, and prey–prey association between P. ulmi and T. urticae in both localities. The analysis of the population dynamics showed delayed occurrence of predatory mites compared with the spider mites, from 48 to 106 days for A. andersoni and 91 to 137 days for Z. mali depending on the research period and locality.

Omnimite 500 efficacy studies in control of Panonychus ulmi Koch

In the paper are given efficacy study results of the pesticide Omnimite 500 (a.i. propargiet) in control of Panonychus ulmi Koch on the apple of Ajdared variety. Studies were performed in two localities, Beska and Irmovo. Treatment was performed twice in 15 days period in June and July 2002. Very significant initial population was previously monitored. Evaluation shows high efficacy in all four replications. In apple orchards in the locality Beska, in regard to standard, average efficacy was 94.06. In apple orchards in the locality Irmovo efficacy was in average higher, i. e. 98.11%.