Визначення поліморфних варіантів фрагментів ДНК збудників хламідійних інфекцій сільськогосподарських тварин

Abstract

Under the currently existing classification, adopted at the Second European Symposium «Animal Chlamydioses and Zoonotic Implications (EMAC-2)», Chlamydia pathogens of animals and humans are intracellular gram-negative bacteria belonging to Chlamydiales order, Chlamydiaseae family, Chlamydia genus. The above mentioned genus includes 11 species: C. abortus, C. avium, C. caviae, C. felis, C. gallinacea, S. muridarum, C. pecorum, C. pneumoniae, C. psittaci, C. suis and C. trachomatis, 10 of them being pathogenic for animals and Chlamydia trachomatis being exclusively human Chlamydiosis agent. Development of highly sensitive and specific molecular genetic test systems for indication and species differentiation of the said Chlamydia genus bacteria will permit to reliably study various aspects of chlamydial infection. Aim of the study was to perform bioinformatiс alignment of different genes’ nucleotide sequences to determine polymorphic DNA regions of Chlamydia genus bacteria, which are the basis for designing oligonucleotide primers for molecular genetic test systems capable of differentiating pathogens, causing disease in cattle and small ruminants, horses and pigs, by species. Bioinformatic study has been performed in 411 primary nucleotide DNA sequences of genes encoding 16S rRNA, RNase P RNA and MOMP of four chlamydial infections agents of farm animals (C. abortus, C. pecorum, C. pneumoniea, C. suis) obtained from the international electronic databases «GenBank» and «PubMed». Meanwhile, it was determined that the gene encoding the main outer membrane protein (MOMP) of Chlamydia possesses the highest variability level, making 97.1%. Using the method of aligning the primary sequences of the said gene, by means of «MEGA4» and «MEGA7» software, polymorphic fragments of nucleotide DNA sequences have been determined for C. abortus, C. pecorum, C. pneumoniea and C. suis. Specificity testing of polymorphic fragments, determined for each of the four chlamydia species with nucleotide sequences of microorganisms, both opportunistic and other infections pathogens, was carried out using «Blast» online software applications. Polymorphic fragments of the gene encoding MOMP of the above Chlamydia genus bacteria will be used to design oligonucleotide primers of test systems for indication and specific differentiation of farm animals’ chlamydial infections agents in polymerase chain reaction.