Analysis of the condition of microbiocenoses and antibiotic resistance on a dairy farm in three-year dynamics

The researches studied opportunistic microbiocenoses at different technological sites of a commercial dairy farm in a three-year dynamics. The composition and sensitivity of the opportunistic pathogenic microflora to antibiotics were determined. It was established that the generic and species composition of the core of microbiocenoses was represented by typical opportunistic strains and was characterized by relative constancy at each site. The most common representatives were Enterococcus spp., P. aeruginosa, Proteus spp., S. aureus, E. coli, and C. albicans. A comparative analysis of antibiotic resistance in 2017 and 2020 revealed an upward trend in AMR. At all the examined sites, an increase in the proportion of microorganisms with reduced sensitivity to three or more antibiotics was revealed. An increase in the number of multi-resistant isolates was found in the calve site

Inhibitory effect of plant metabolites of Nigella sativa on conditionally pathogenic microflora of productive animals

Objective: The effectiveness of a phytobiotic based on active metabolites of Nigella sativa L. against typical microorganisms of opportunistic microbiocenosis of the mucous membranes of highly productive cows was studied. Initially, the inhibitory activity of the phytobiotic was studied on cultures of wild multi-antibiotic-resistant isolates of P. aeruginosa and S. aureus isolated on a commercial dairy farm. It was found that the phytobiotic had the ability to inhibit the growth of isolates on the nutrient medium, but the severity of the inhibitory effect varied notably. At the second stage, an experiment was conducted with the local application of phytobiotics on cows that had inflammatory complications of the postpartum period. The results of the experiment showed a pronounced inhibitory effect of the phytobiotic on S. aureus, Str. uberis, P. aeruginosa, E. cloacae, C. albicans, and P. mirabilis. There was an involution of inflammatory symptoms and normalization of the clinical and microbiological state of the mucous membrane after the use of a phytobiotic preparation

The influence of phytobiotic based on essential oils of Salvia sclarea, Mentha canadensis, Mentha piperita and Coriandrum sativum on pathogenic microorganisms of lactating cow udder

The antibacterial activity of a phytobiotic based on the essential oil complex Salvia sclarea, Mentha canadensis, Mentha piperita and Coriandrum sativum for external use in inflammatory processes of the cow udder was studied. The microflora composition and microbial associations of pathogens were studied before and after the treatment of the nipples with the preparation. It was found that after the phytobiotic application, the frequency of detection on the mucous membranes of Str. uberis, P. aeruginosa, C. albicans, S. aureus, E. coli, Salmonella spp decreased. The number of associations of pathogenic strains decreased, and the severity of the inflammatory process decreased

Pilot Screening of Cell-Free mtDNA in NIPT: Quality Control, Variant Calling, and Haplogroup Determination

Clinical tests based on whole-genome sequencing are generally focused on a single task approach, testing one or several parameters, although whole-genome sequencing (WGS) provides us with large data sets that can be used for many supportive analyses. In spite of low genome coverage, data of WGS-based non-invasive prenatal testing (NIPT) contain fully sequenced mitochondrial DNA (mtDNA). This mtDNA can be used for variant calling, ancestry analysis, population studies and other approaches that extend NIPT functionality. In this study, we analyse mtDNA pool from 645 cell-free DNA (cfDNA) samples of pregnant women from different regions of Russia, explore the effects of transportation and storing conditions on mtDNA content, analyse effects, frequency and location of mitochondrial variants called from samples and perform haplogroup analysis, revealing the most common mitochondrial superclades. We have shown that, despite the relatively low sequencing depth of unamplified mtDNA from cfDNA samples, the mtDNA analysis in these samples is still an informative instrument suitable for research and screening purposes