Background and Aim: Several reports described the detection of specific caprine arthritis-encephalitis virus (CAEV) antibodies in Russian goat populations, which indicates the circulation of CAEV in Russian goat farms. The aim of this study was to use a multi-target approach to testing with both serological tests and an in-house real-time (RT) molecular test to investigate the prevalence of CAEV in goats from three hobbyist farms in the Republic of Tatarstan, Russia. Materials and Methods: We applied a multi-target approach to testing with both enzyme-linked immunosorbent assay (ELISA) and an in-house RT polymerase chain reaction test to investigate the prevalence of CAEV in goats. Animals from the three hobbyist farms were used in this study. The animals from two farms (n=13 for F1 and n=8 for F2) had clinical signs of arthritis and mastitis. In the third farm (n=15 for F3), all goats were home-bred and had no contact with imported animals. Results: CAEV antibodies (ELISA targets TM env and gag genes) were detected in serum samples from two farms (F1 and F2), indicating seroprevalence of 87.50-92.31%. Specific CAEV antibodies were also detected in milk samples. CAEV proviral DNA was detected in 53.85-62.50%. The results from all tests performed in the third farm (F3) were negative, indicating that all tests were 100% specific. Conclusion: The results showed that CAEV is circulating and present in small hobbyist goat farms in Russia. Serological and molecular tests could be important for programs to control and eradicate CAEV in Russia for hobbyist goat farms.

Bacillus anthracis is the anthrax causative agent. For its epidemiology, it is important not only to identify the etiological agent but also to determine the patterns of its evolution and spread. Modern methods of molecular biology make it possible to detect a number of genetic markers suitable for indicating and differentiating the strains of B. anthracis, including the loci arranged as variable number tandem repeats (VNTRs) and SNPs, one nucleotide-sized differences in the DNA sequence of the loci being compared. The objective of the present study was to examine the effectiveness of SNP analysis and PCR amplif ication of VNTR loci combined with the high-resolution amplicon melting analysis for identif ication and differentiation of the anthrax agent strains. In the study, seven strains of B. anthracis obtained from soil samples and animal carcasses were investigated using vaccine strain STI-1 as a reference. For molecular genetic characterization of these bacteria, analysis of 12 SNPs and variability analysis of eight VNTR loci were carried out. To detect the differences between the strains, their PCR product melting points were measured in the presence of the EvaGreen (Sintol, Russia) intercalating dye. For SNP detection, a PCR assay with double TaqMan probes was applied. It was found that the studied virulent strains, except for B. anthracis No. 1 and 3, could not be attributed to any phylogenetic subgroup of the anthrax agents. The proposed method made it possible to differentiate four out of the seven investigated strains. Strains No. 5–7 had identical SNP and HRM prof iles and, as a result, formed a single cluster. Our investigation has conf irmed that the proposed method can be successfully used for preliminary analysis of an epizootic situation in the case of anthrax.

The aim of the present study was to evaluate the effectiveness of analysis of the high resolution melting curves obtained after amplification of VNTR loci for the identification and differentiation of Brucella strains.Materials and methods. 16 strains of Brucella species – B. canis (n=1), B. abortus (n=9), B. melitensis (n=2), B. suis (n=4) – of different geographical origin were used as objects of the research. The MLVA-typing was performed using conventional PCR followed by separation of amplicons in agarose gel and real-time PCR with post-amplification analysis of the curves of VNTR loci melting in the presence of intercalating dye SybrGreen. Bioinformatics analysis was conducted with the help of Vector NTI 9.1, Mega 11 software (MUSCLE algorithm). Phylogenetic analysis was carried out applying UPGMA method using the Mega 11 program.Results and discussion. MLVA approach based on the analysis of the melting point curves of the obtained after amplification of VNTR-loci PCR fragments has shown that each of the 16 strains of Brucella is characterized by a unique melting temperature profile. PCR followed by electrophoresis has demonstrated that despite the high variability of the used VNTR sequences (h=0.48…0.74), only post-amplification melting curves of the Bru7, Bru9, Bru18, Bru21 loci had sufficient information content to determine the genetic polymorphism of the studied Brucella strains. Based on the results of phylogenetic analysis of the Bru7, Bru9, Bru18, Bru21 sequences, it has been found that the majority of the studied Brucella strains are distributed in the dendrogram in accordance with their taxonomic and geographical position. Thus, HRM analysis of melting curves obtained after amplification of the Bru7, Bru9, Bru18, Bru21 loci has the potential to be used for differentiating Brucella strains.

При организации противолейкозных мероприятий наиболее эффективно использование серологических и молекулярно-генетических диагностических методов в комбинации. Выбор данного подхода можно объяснить особенностями развития инфекционного процесса при лейкозе крупного рогатого скота (КРС). В инкубационном периоде заболевания серологические методы малоэффективны, так как в крови отсутствуют специфические антитела или синтезируются в малых количествах. Однако определение наличия возбудителя лейкоза КРС возможно в случае применения молекулярно-генетических методов для выявления специфичного участка генома вируса. Особенности инфекционного процесса данного заболевания подразумевают периоды, при которых ни генетические, ни серологические маркеры не способны идентифицировать патоген, такую ситуацию можно преодолеть, применив подход, в котором каждое животное с отрицательной реакцией проверяется повторно через 3 месяца. При таком подходе (в том числе при совместном применении серологических (ИФА) и генетических исследований) возможно оздоровить хозяйство в кратчайшие сроки. В статье приведены данные по сравнительной диагностической оценке серологических и молекулярно-генетических методов лабораторной диагностики лейкоза КРС. С помощью РИД выявлено 21,5% инфицированного КРС, ПЦР-РВ – 22,3%, ИФА – 22,0%. Также был проведен эпизоотический мониторинг по лейкозу КРС в хозяйствах Республики Татарстан за 2011-2021 гг. Установлено, что пик зараженности был в 2013 г. С 2014 г. отмечается нисходящий тренд процента инфицированности КРС. В 2017 г. регистрировано незначительное увеличение числа больных животных. В последующие годы количество больного крупного рогатого скота уменьшается.