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Continuous entomological monitoring of Cullicoides spp., which is being conducted starting from 2014 have so far yielded significant results related to biodiversity and seasonal dynamics of these insects Serbia. The research we have done so far has contributed to mapping the geographical distribution of the species we encounter as well as the variations in the number of populations in different years. As monitoring continues, we receive new valuable data every year that will help predict the movement of these insects on the basis of biclimatograms and enable preventative action to be taken to counteract them. Unfortunately, starting in 2019, monitoring has been split into three institutions (NIVS Belgrade, NIV Novi Sad and VSI Kraljevo) so that this has lost insight into the biodiversity, sex ratio, and most importantly the age of the females that are the primary vectors. In our work, therefore, we can provide only the results of testing the biodiversity and seasonal dynamics of Cullicoides spp. during 2019 in the epizootiological area of NIVS Belgrade, VSI Šabac, VSI Pančevo, VSI Požarevac, and VSI Zaječar, while we did not divide samples from VSI Jagodina for the fourth consecutive year. Culicoides spp. from Obsoletus complexes were established at 59.91%, from the Pulicaris complex were established at 34.06% and other types of culicoids have been established in less than 10% of the examined samples.

The outbreak of lactococcosis affecting rainbow trout, weighing 70 - 120 g, occurred at a trout aquaculture facility in Central-West Serbia during July, 2018. This outbreak lasted for three weeks, and cumulative mortality attributed to the disease was around 40%. The diseased fish showed erratic swimming, dark discoloration and exophthalmia, with the cumulative mortality of around 40%. A pure Gram-positive cocci isolates were obtained from the eye and kidney samples. Based on colony morphology, phenotypic and biochemical characteristics, the isolated bacterium was presumably identified as Lactococcus garvieae. Using the BBL CRYSTAL GP ID system, the isolate was identified as L. garvieae and the identity of the isolate was confirmed with MALDI-TOF Mass Spectrometry. Blast analysis of 16S rRNA sequence of our isolate had a 99.4 to 99.6% similarity to the L. garvieae strains previously isolated from diseased fish. The antibacterial activity of 15 antimicrobials against L. garvieae was evaluated using disc diffusion. In this paper, we report the first case of lactococcosis in rainbow trout in Serbia, isolation and characterization of causative agent, Lactococcus garvieae from diseased rainbow trout.

Genus Culicoides spp. includes small insects 0.5-2 mm in length, usually grey or black and at first glance very similar to mosquitoes. They are strictly hematophagous, feeding by attacking hosts outdoors and indoors (although they are less susceptible to the stationing like Aedes mosquitoes do). The sting is very painful at the injection site and often followed by hypersensibilisation with the consequent formation of allergic dermatitis. In addition, the insects carry and transmit a multitude of diseases, often of a zoonotic character, and therefore are of great epidemiological importance. In our country, continuous monitoring of Culicolides spp. has been carried out and seasonal dynamics of their appearance in the period 2015-2016 is presented in this article. During October 2015, the presence of Culicolides spp. was confirmed in 10.00% of samples; in November, their presence was not established, whereas in December, 2.35% of samples proved positive for the presence of Culicolides spp. During 2016, from January to March, no Culicolides spp. were found in any of the examined samples. During April, their prevalence was 9.63%, in May - 6.74%, in June - 3.70%, in July - 15.78%, in August - 18.07%, in September - 27.27%, and in October - 45.65%. In Serbia, the dominant Culicoides spp. species are Obsoletus complex and Pulicaris complex established in 57.21% and 33.37% of samples, respectively. Other species are present in lesser extent. In Obsoletus complex, the dominant species was Culicoides obsoletus/scoticus. The percentage of Culicoides obsoletus /scoticus males in samples was 25.52%. Non-pigmented (young) females were present in 66.06% of samples; females who took blood in 7.55% and 0.87% were gravid females. In Pulicaris complex, the dominant species was Culicoides pulicaris. Males of Culicoides pulicaris were found in 19.23% of samples, non-pigmented (young) females in 70.96%, females who took blood in 9.08% while 0.73% were gravid females.

During 2017, 784 insect samples were examined and the presence of Culicoides spp. was established in 25.51% of samples. Earlier research has found that the dominant population of Culicoides spp in Serbia belongs to Obsoletus complexes, established in 60.05% of analyzed samples. Out of the entire insect population analyzed, males were found in 22.84%, unpigmented (young) females in 67.97%, females who took blood in 7.39%, whereas 1.35% were gravid females. Culicoides spp. from the Pulicaris complex was established in 38.85% of examined samples. Males were found in 18.91%, unpigmented (young) females in 71.72%, females who took blood in 9.09%, and 1.11% were gravid females. Other types of culicoids have been established in less than 10% of the examined samples. During examination, the most prevalent species were Culicoides obsoletus, C. picturalis, C. lupicaris, C. scoticus and C. fascipennis.

Listeriosis is an infective disease of many animals and humans (zoonosis). Clinically it is manifested in various forms, mostly as abortion and meningitis. The cause is Listeria monocytognes. It is an ubiquitar bacteri, found in over than 40 mam mals, 20 bird species, several fish species and insects. After infection, clinical symptoms are some times not diagnosed and the animals arrive in slaughter house as healthy animals (unapparent infection). When animals, in this case goats, arrive for slaughter, the cause of the disease can be transmitted on the equipment and possibly on meat. In our examination, immediately after slaughter of clinically healthy goats, 20 swabs were taken from the bottom of trolleys for placing of the organs, 5 swabs from knives (between glade and grip) and 20 swabs from the floor. Three days af ter slaughter, 10 swabs were taken again from floor (from ten different places) and from the bottom of trollies (20 swabs) where the intestine and uterus were placed. The swabs were incubated in selective, enriched broth refrigerated at 5-8°C. On the third and seventh day they were inoculated on blood agar (5% sheep blood), Columbia (Himedia) and MacConkey agar (Biomedics) and incubated under the temperature of 37°C for 24-48 hours. the suspect colonies from blood and Columbia agar were controlled microscopically and, because of getting pure culture, re-cultivated on the same media. For examination of biochemical activity, commercial tests were used. For the identification BBL Crys tal G/P ID kit was used. Listeria monocytogenes was iso lated from two floor swabs, one knife swab and from two swabs from trollies. Except the one from floor, each isolate of Listeria monocytogenes was isolated from the broth inoculated for seven days. Listeria monocytogenes was iso lated from two floor swabs three days after slaughter. These isolates were isolated from the broth inoculated for seven days. Our finding shows the possibility of in direct transmission of Listeria monocytogenes on meat.