Blood smears stained with Diff Quick are the initial tool for cytological diagnosis of Haemogregarina spp. However, the development of sensitive and specific molecular methods enabled the detection and identification of parasites in the sample and to clarify the evolutionary relationships of adeleorinid parasites within the Apicomplexa. The current study was attempted in order to perform cytological investigation and molecular identification of the hemoparasites in thirty European pond turtles (Emys orbicularis) from the quarantine section at Belgrade Zoo, which have been found in poor health condition with massive skin hemorrhages, based on intraerythrocytic parasitic forms on hematological smears and 18S rDNA sequence, respectively. Different life cycle stages of the Haemogregarina sp. were noticed within the erythrocytes in the peripheral blood. Biochemical analysis indicated lower values of AST and iron in most of the infected turtles while hematological analysis showed a changed hematocrit value, a decrease in the number of red blood cells and low hemoglobin levels. Amplifications of the 18S rDNA sequence of Haemogregarina were detected in 30/30 (100%) turtles with clinical symptoms. The identity of PCR products was confirmed by direct DNA sequencing. Future research concerning H. stepanowi in Serbia should be applied to its definitive host-the leech.

The aim of the study was to characterize multidrug-resistant (MDR) Escherichia coli isolates collected in Serbia from bovine clinical mastitis cases and diseased pigs, mainly with molecular methods. A total of 48 E. coli isolates was collected during the years 2013–2014, of which 22 were MDR and were included in further analysis. Phylogenetic typing showed that 17 isolates belonged to group A, while two isolates were classified in group B1 and a single one in group D. All isolates showed unique macrorestriction patterns. Phenotypic susceptibility testing revealed resistances of the isolates against up to 13 antimicrobial agents, including resistance to fluoroquinolones. A wide variety of resistance genes was detected by PCR amplification and sequencing of amplicons. Sequence analysis of the quinolone resistance determining regions of topoisomerase genes revealed mutations in gyrA , parC , and/or parE . Plasmid-mediated quinolone resistance genes were detected in two porcine ( aac-6’-Ib-cr and qnrS , respectively) isolates and a single bovine ( aac-6’-Ib-cr ) isolate. Resistance genes were found to be located on conjugative plasmids in 16 cases, many of which conferred a multidrug resistance phenotype. In conclusion, the plentitude of resistance genes located on conjugative plasmids and integrons in E. coli from cows and pigs in Vojvodina, Serbia, pose a high risk for horizontal gene transfer in bacteria from livestock husbandry.

Being an important pathogenic and indicator microorganism, E. coli has been included in all the resistance follow up programs worldwide. We carried out sampling on 42 cattle, pig and poultry farms. After sampling the material was delivered to the laboratories, where it was exposed to standard treatment and streaking by standard methods of microbiological diagnostics with the aim to isolate and identify E. coli strains. On the selected isolated E. coli strains an investigation of its sensitivity to a certain number of antimicrobial agents (ampicillin, tetracycline, chloramphenicol streptomycin, neomycin and sulphametoxasol) was carried out. After obtaining the results from each farm for the three different animals categories (young healthy, young unhealthy, adult), 60 E. coli strains for eachcategori were isolated to be examined for sensitivity to 17 antibiotics and chemotherapeutics. The investigation included a total of 180 E. coli strains originating from cattle, pigs and poultry. For the investigation of isolated E. coli strains Mueller Hinton broth and agar, antibiogram tablets (Torlak Belgrade) as well as discs by Becton Dickinson, BBL (USA) were used In isolated E.coli strains resistance to investigated antimicrobial agents was significantly different depending on the species age and health status of the animals. The majority of the isolated E. coli strains examined for 17 antibiotics and chemotherapeutics showed a resistance to 15, and sensitivity only to cephalosporines of the III generation and colistin.

Resistance to tetracycline was studied in Salmonella Infantis isolated from 28 poultry farms in the Northern part of Serbia (The Autonomous Province of Vojvodina). A total of 18 isolates were resistant to nalidixic acid (NAL) and tetracycline (TET). The minimal inhibitory concentration (MIC) to TET, ranged from 1-256 mg/L. Namely, 13 isolates exhibited MIC to TET at 256 mg/L, in four of the isolates, the MIC was 128 mg/L and one isolate had MIC 64 mg/L. Ten isolates were exhibiting a MIC of 1mg/L. It was evident that Salmonella Infantis had also spread to breeders and layers. In this work, we detected the tetA gene and the corresponding tetR gene (encoding the repressor protein) as well as the truncated transposon Tn1721, which are responsible for the resistance to TET. The presence of the non conjugative transposons from the conjugative plasmid has facilitated the spread of resistance to TET in Salmonella. It was concluded that higher biosecurity practice in poultry farming presents the best option to eliminate infections caused by Salmonella spp. from poultry fl ocks in Serbia. A rational use of antimicrobials is necessary to prevent any further spread of Salmonella Infantis resistant clones.

Porcine parvoviruses (PPVs) are diverse and persistently evolving viruses found in domestic pigs and wild boars. Porcine parvovirus 1 (PPV1) causes reproductive problems in adult animals, although the veterinary relevance of PPV2, PPV3, and PPV4 has not been clarified. The detection and sequence analysis of PPVs circulating in wild boar populations in Serbia was performed to determine their phylogenetic relationships and prevalence in 122 organ samples collected during 2018. The DNA of PPV1, PPV2, and PPV3 was detected in 56.6% of the examined samples, whilst PPV4 was not identified. Overall, PPV3 was the most prevalent in 69.6% of the positive samples, followed by PPV1 in 63.8%, and PPV2 in 21.7% samples. Single infections were more common, although concurrent infections were confirmed in 34.8% samples for two, and 10.1% samples for three viruses. Sequence analysis of wild boar PPV1 showed no significant nucleotide differences from domestic pig PPV1 strains detected in Europe and the USA, however separate clustering from strains from China and the NADL-2 strain was demonstrated. Examination of the selected PPV2 sequences might suggest a certain geographical distribution of genetically diverse PPV2 strains considering high similarities to the strains from neighboring countries, and variability in comparison with other reported PPV2 sequences from different parts of the world. Wild boar PPV3 sequences clustered separately from most of the strains detected in wild boars, as well as the original porcine hokovirus strain. It is further noted that genetically different PPV3 strains circulate amongst Serbian domestic pigs and wild boars.