Rezistentnyye k karbapenemam shtammy Pseudomonas aeruginosa rastsenivayut v kachestve kriticheski opasnykh patogenov pervogo urovnya prioriteta. Rasshifrovka mekhanizmov formirovaniya ustoychivosti k karbapenemam yavlyayetsya aktual'noy zadachey sovremennoy meditsinskoy nauki. Tsel'yu raboty bylo opisat' raznoobraziye i zakrepleniye mutatsiy, assotsiirovannykh s formirovaniyem karbapenemrezistentnosti v protsesse adaptatsii P. aeruginosa k povyshayushchimsya kontsentratsiyam meropenema. Ob"yektami issledovaniya byli izolyaty P. aeruginosa, poluchennyye pri roste referentnogo shtamma P. aeruginosa ATCC 27853 v gradiyente vozrastayushchikh kontsentratsiy meropenema. Otsenku chuvstvitel'nosti izolyatov k meropenemu vypolnyali pri pomoshchi ye-testov (epsilometricheskiy metod) s meropenemom i pri pomoshchi metoda dilyutsii antibiotika v agare. Genomy izolyatov byli sekvenirovany na polnogenomnom sekvenatore MGISEQ-2000. Poluchennyye rezul'taty pokazali, chto formirovaniye vysokikh urovney rezistentnosti k meropenemu u P. aeruginosa v eksperimente proiskhodit v korotkiye sroki (6 sutok). Evolyutsiya rezistentnosti sopryazhena s protsessom klonirovaniya, pri kotorom proiskhodit vozniknoveniye mnozhestva klonov s razlichnymi genotipami. Osnovoy klonirovaniya yavlyayetsya mutagenez, v kotoryy vovlecheny 11 genov, vklyuchaya oprD, pbuE, nalD, nalC, spoT, mlaA, mexD, mexR, oprM, mraY, pbp3. Chast' obrazovavshikhsya klonov, nezavisimo ot urovnya ikh rezistentnosti k meropenemu, ne poluchayut progressivnogo razvitiya i vytesnyayutsya boleye uspeshnymi klonami.

Генетико-эпидемиологическими исследованиями установлено, что полиморфные варианты генов ферментов антиоксидантной системы являются значимыми предикторами риска развития и тяжести проявления ишемического инсульта (ИИ). Целью настоящего исследования было изучение ассоциации трех частых однонуклеотидных полиморфизмов (SNP) rs38420, rs4270 и rs6462210 гена гамма-глутамилциклотрансферазы (GGCT) - ключевого фермента катаболизма глутатиона с риском развития ИИ и функциональное аннотирование этих SNPs. Материалом для исследования послужили образцы ДНК 1288 неродственных индивидов славянского происхождения, в том числе 600 пациентов с диагнозом ИИ и 688 относительно здоровых добровольцев. Генотипирование полиморфных вариантов гена GGCT осуществлялось с использованием технологии iPLEX на генетическом анализаторе MassARRAY-4. Функциональное аннотирование SNPs осуществлялось биоинформатическими методами с использованием различных онлайн-инструментов и баз данных. Установлена ассоциация генотипа TT SNP rs6462210 с пониженным риском развития ишемического инсульта (OR=0,36 95%CI 0,15-0,85, p=0,01). Биоинформатический анализ регуляторного потенциала исследованных полиморфных вариантов показал, что их фенотипические эффекты проявляются ослаблением транскрипционной активности гена GGCT преимущественно в клетках крови и артериях, главным образом, в результате химических модификаций хроматина. У полиморфизма rs4270, находящегося в тесном неравновесии по сцеплению с SNP rs6462210 (D’=0,966, p<0,01), обнаружен участок связывания c микроРНК hsa-miR-1246, способной блокировать экспрессию GGCT, тем самым, способствуя снижению образования L-цистеина - предшественника глутатиона. В результате исследования впервые показано, что вариабельность гена GGCT может вносить вклад в развитие ИИ. Экспериментальные исследования по оценке регуляторного потенциала полиморфных вариантов гена GGCT потребуются для патофизиологической интерпретации выявленных ассоциаций. Genetic epidemiological studies have established that polymorphisms of the genes encoding antioxidant defense enzymes represent meaningful predictors for the risk and severity of ischemic stroke (IS). The aim of this study was to investigate associations of IS with three common single nucleotide polymorphisms (SNPs) such as rs38420, rs4270 and rs6462210 in gamma-glutamylcyclotransferase (GGCT) gene, a key enzyme of glutathione catabolism. DNA samples obtained from 1288 unrelated individuals of Slavic origin, including 600 patients with IS and 688 healthy volunteers were included in the study. Genotyping of the GGCT polymorphisms was done using an iPLEX-based technology by the MassARRAY-4 system. Functional annotation of SNPs was performed using numerous online bioinformatics tools and resources. We found an association between genotype T/T rs6462210 and a decreased risk of ischemic stroke (OR = 0.36 95% CI 0.15-0.85, p=0.01). The haplotype rs38420A-rs4270T-rs6462210C showed a clear tendency in association with decreased disease risk (p=0.057). Bioinformatics analysis showed that the phenotypic effects of the SNPs are characterized by a weak transcriptional activity of the GGCT gene mainly in blood cells and arteries as a result of chemical modifications of chromatin. For the rs4270 polymorphism, which is in close linkage disequilibrium with SNP rs6462210 (D’=0.966, p<0.01), we found a binding site for miRNA hsa-miR-1246 which is capable to block the GGCT expression, thereby reducing the formation of L-cysteine, a precursor of glutathione. The study showed for the first time that GGCT gene may contribute to the development of ischemic stroke. Experimental studies focusing on the regulatory potential of GGCT gene polymorphisms are required for the pathophysiological interpretation of the identified associations.

Disbalans mezhdu obrazovaniem aktivnyh form kisloroda i ih obezvrezhivaniem lezhit v osnove okislitel'nogo stressa — patologicheskogo processa, patogeneticheski svyazannogo s razvitiem ishemicheskogo insul'ta (II) i posleduyushchimi etapami postishemicheskogo povrezhdeniya tkanej golovnogo mozga. Cel'yu nastoyashchego issledovaniya bylo izuchenie vliyaniya chastyh polimorfnyh variantov gena GCLC kataliticheskoj sub"edinicy glutamatcisteinligazy na stepen' porazheniya golovnogo mozga i klinicheskie proyavleniya u bol'nyh s ishemicheskim insul'tom. U 589 pacientov s ishemicheskim insul'tom bylo provedeno genotipirovanie shesti odnonukleotidnyh polimorfizmov (SNP) rs12524494, rs17883901, rs606548, rs636933, rs648595 i rs761142 gena GCLC s pomoshch'yu geneticheskogo analizatora MassARRAY-4. Ustanovleno, chto genotipy rs636933-G/A-A/A (r = 0,009) i rs761142-A/C-C/C (r = 0,015) associirovany s uvelicheniem zony infarkta mozga. Genotipy rs12524494-G/G (r = 0,05) i rs606548-T/T (r = 0,003) associirovalis' s vozniknoveniem dvuh i bolee epizodov II. Genotip rs17883901-G/A byl associirovan s bolee rannim debyutom II (r = 0,004). Vyyavleny mnogochislennye associacii SNP gena GCLC s klinicheskimi proyavleniyami bolezni. Takim obrazom, polimorfnye varianty gena GCLC yavlyayutsya znachimymi DNK-markerami, vliyayushchimi na zonu infarkta mozga u bol'nyh ishemicheskim insul'tom, associirovany s vozrastom debyuta pervogo insul'ta, chislom perenesennyh insul'tov i klinicheskimi proyavleniyami bolezni.

Nontyphoid strains of Salmonella enterica pose a great threat to human health. The problem of salmonellosis is aggravated compounded by the progressive spread of antibiotic resistance among clinical and agricultural strains of S. enterica. This literature review summarizes the current knowledge of the mechanisms of antibiotic resistance in S. enterica and illustrates the diversity and complexity of molecular systems providing antibiotic resistance. The spectrum of natural resistance is described and the adaptive (acquired) mechanisms of resistance to representatives of the main classes of antibiotics, including fluoroquinolones, aminoglycosides, tetracyclines, nitrofurans, sulfonamides, fosfomycin and chloramphenicol, are thoroughly characterized. Particular emphasis is placed on the analysis of the molecular genetic mechanisms of S. enterica resistance to representatives of the most important classes of antibiotics — β-lactams, and to reserve antibiotics — polymyxins (colistin). Genetic determinants of resistance, transmitted by a horizontal path route are also described. The review analyzes only those variants of the molecular mechanisms of antibiotic resistance where the clinical significance has been proven by a set of correct genetic (sequencing) and biochemical (confirmation of the spectrum of hydrolyzed β-lactams) studies. The main ways of regulating the expression of antibiotic resistance are also described. Many S. enterica strains exhibit a combination of different mechanisms of antibiotic resistance and have a multiple resistance. The question was raised about the heterogeneity of the distribution of resistance among different groups/serotypes within the S. enterica species. In particular, some clonal complexes with signs of resistance are more successful pathogens in humans and animals. Salmonella, like most other bacteria, exhibit a non-canonical type of antibiotic resistance — biofilm resistance, which is realized through several mechanisms, the main of which are the filtering/sorption capacity of the biofilm matrix and the transformation of biofilm cells into dormant and persistent forms.Despite the fact that the functional significance of the molecular assemblies that determine antibiotic resistance is the same for all enterobacteria, the specification of the mechanisms of resistance in Salmonella is a necessary link for the development of molecular diagnostic systems for assessing the sensitivity to antimicrobial drugs.

Nechuvstvitel'nye k antibiotikam shtammy Pseudomonas aeruginosa predstavlyayut soboj global'nuyu problemu v zdravoohranenii. Issledovanie mekhanizmov vozniknoveniya rezistentnosti lezhit v osnove razrabotki sposobov bor'by s P. aeruginosa. Cel'yu raboty bylo issledovat' vozniknovenie kross-rezistentnosti u P. aeruginosa v processe adaptacii k populyarnomu antibiotiku meropenemu. Ob"ektami issledovaniya byli obrazcy P. aeruginosa, poluchennye pri roste referentnogo shtamma P. aeruginosa ATCC 27853 na srede s vozrastayushchej koncentraciej meropenema. CHuvstvitel'nost' izolyatov k karbapenemam i kolistinu opredelyali pri pomoshchi razvedeniya v agare, chuvstvitel'nost' k kolistinu ocenivali metodom serijnyh razvedenij. Bylo polucheno 93 izolyata P. aeruginosa, dva iz kotoryh imeli snizhennuyu chuvstvitel'nost' odnovremenno k karbapenemam (meropenem, imipenem) i kolistinu. Genomy izolyatov sekvenirovali na polnogenomnom sekvenatore MGISEQ-2000; obnaruzheny missens-mutacii v genah oprD i mexD i nonsens-mutaciya v phoQ. Poluchnnye rezul'taty pokazyvayut, chto pri vozdejstvii meropenema na shtammy P. aeruginosa mozhet razvivat'sya kross-rezistentnost' k kolistinu — preparatu rezerva dlya lecheniya sinegnojnoj infekcii.