Name
Коnоnеnко Sergey Ivanovich
Scholastic degree
•
Academic rank
professor
Honorary rank
—
Organization, job position
Kuban State Agrarian University
North-Caucasus Research Institute of Animal
Web site url
—
Articles count: 32
A method of obtaining insertion mutants for the hoc
gene, which encodes for the main phage antigen, was
developed on the model of bacteriophage T4. This gene
was cloned in the plasmid pBSL0+ and was disrupted
by insertion of foreign DNA. The phage mutants were
obtained by in vivo phage-plasmid recombination. The
construction of insertion bacteriophage mutants was
carried out in two stages. The resulting mutants on this
procedure could be grown on wild-type E. coli strains,
which is convenient for the production and use of these
phages in therapy. The mutants obtained had reduced
antigenicity. At the same time, the yield of the mutant
strains was high when they were grown on the
non-suppressor E. coli laboratory strains. A number of
stages of purification of the bacteriophage mutants
obtained were performed. Preparations have been
studied by transmission electron microscopy and mass
spectrometry. By several periodic cultivations of the
mutant bacteriophages, it was shown that mutations of
this type are stably maintained during more than 50
generations. T4 related bacteriophages of the family
Myoviridae, for example, T-even, have the significant
homology amongst their genomes, which makes
possible to produce similar mutants. Thus, our method
was developed to obtain mutants with reduced
antigenicity which can be used for both the treatment of
systemic infections, and diarrhea in the case, when,
bacteriophages penetrate into the bloodstream. Such
phages can be used in medicine and veterinary. The
reported study was partially supported by RFBR,
research projects No. 13-04-00991, 16-44-230855
The main diseases of lactating cows occur in the first
two months of lactation, i.e. during the production
peak of productivity. They are caused by the changes
in metabolism during the transition period, which are
not supported by adequate changes in the organization
of feeding, or rather sufficient to ensure cows with
nutrients, which causes a number of closely related
diseases. To allocate any of them is not possible, as
their manifestation depends on a number of reasons,
and depending on situation may prevail one or the
other. Among the most common diseases, there are
ketosis, milk fever (paresis of maternity), dysplasia of
the abomasum, acidosis, mastitis, endometritis,
laminitis and leukemia. These diseases cause the
greatest problems in herds with high productivity, and
are caused by changes in metabolism in cows in the
transition period and the inability to properly feed the
animals at this time. To identify the causes of these
diseases we do not need to study each of them
individually - it is enough to deal with the peculiarities
of metabolism. This period includes the month before
calving and the first or second month of lactation, but
the most important are 3 weeks before calving and 3
weeks later. In order to prevent metabolic disorders
there were developed and tested feed for feeding cows
before calving and immediately after calving. Their
effect was studied on milk production and health status