СТРАТЕГИЯ УПРАВЛЕНИЯ БАКТЕРИАЛЬНЫМ БИОПЛЕНОЧНЫМ ПРОЦЕССОМ

Main directions of the modern search of the antibiofilm preparations aimed at adhesive bacterial reactions, control of QS-systems, influence over bis-(3’-5’)-cyclic dimeric guanosine monophosphate (cdi-GMP), and secretory bacterial processes are analysed. Approaches for biofilm dispersal and increasing the sensitivity of biofilm bacteria to antimicrobial drugs are discussed. It is underlined that the majority of inhibitor molecules were studied in vitro or in infected mice experiments. It is prognosed that in future there will appear medical preparations which will help for fighting bacterial biofilms preventing their development and spreading in the host organism.Проанализированы основные направления современного поиска антибиопленочных препаратов, нацеленных на адгезивные реакции бактерий, управление QS-системами, воздействие на циклический димерный гуанозинмонофосфат (ц-ди-ГМФ), секреторные бактериальные процессы. Обсуждаются подходы, которые используются для отторжения биопленки и повышения чувствительности биопленочных бактерий к антимикробным средствам. Подчеркивается, что большинство ингибиторных молекул исследовалось in vitro или в опытах на инфицированных мышах. Прогнозируется появление медицинских препаратов, которые позволят бороться с бактериальными биопленками, предупреждая их развитие и распространение в организме хозяина

Провоспалительная активность бронхоальвеолярной лаважной жидкости при обострении хронических заболеваний легких

Pro-inflammatory activity of broncho-alveolar lavage fluid (BALF) was investigated in 93 patients with exacerbations of chronic lung diseases using biological test-systems — donor blood and experimental animals (mice). Previously the BALF supernatants were decontaminated by millipore filtration. At the first investigation way BALF was added to the donor blood and examined in nitroblue tetrasolinium reduction test. Hanks’ balanced saline solution was used in the control test instead of BALF. The pro-inflammatory BALF effect was determined as the ratio of diformasan-positive neutrophile percentages in experimental and control groups (stimulation index — SI). At the second way BALF was injected into mice’ trachea. Then mice’ lungs were lavaged in 24 hours. Polymorphnonuclear leucosytes percentage in mice BALF was estimated as a value of the pro-inflamm atory BALF activity in patients (or chemotactic activity, CA). Patients BALF with low inflammatory activity was found to inhibit nitroblue tetrasolinium reduction test with donor blood neutrophiles (S K 1.0) and to stimulate slightly polymorphnonuclear leucosytes migration in respiratory system of recipient mice (CA<10%). On the contrary, BALF in patients with high inflammatory activity was found to stimulate these parameters intensively (Sl>1.5; CA>20%). Thus, our findings suggest that the values of pro-inflammatory BALF activity allow to estimate chronic lung diseases activity and to predict possible complications.У 93 пациентов с обострением хронических заболеваний легких исследовалась провоспалительная активность бронхоальвеолярного смыва (БАС) при использовании биологических тест-систем — донорской крови и экспериментальных животных (мышей). Супернатант БАС предварительно очищали фильтрацией через миллипоры. В первом варианте исследования лаважную жидкость добавляли к донорской крови и ставили тест восстановления нитросинего тетразолиния. В контроле применяли сбалансированный солевой раствор Хенкса. Провоспалительный эффект бронхоальвеолярного смыва определяли как соотношение содержания диформазан-положительных нейтрофилов в экспериментальной и контрольной группах (индекс стимуляции — ИС). Во втором варианте БАС вводили в трахею мышей и через 24 часа проводили бронхоальвеолярный лаваж. За показатель провоспалительной активности БАС пациентов принимали процент полиморфно-ядерных лейкоцитов лаважной жидкости (хемотоксическая активность, ХА). БАС больных с низкой воспалительной активностью подавлял реакцию восстановления нитросинего тетразолиния нейтрофилами донорской крови (ИС<1,0) и слегка стимулировал миграцию полиморфно-ядерных нейтрофилов в респираторную систему мышей-реципиентов (ХА<10%). Напротив, БАС больных с высокой активностью воспаления стимулировал эти параметры более интенсивно (ИС>1,5; ХА>20%). Таким образом, наши исследования позволяют предположить, что оценивая противовоспалительную активность бронхоальвеолярных смывов, можно определять степень активности хронических заболеваний легких и прогнозировать возможные осложнения

sIgG4 и другие предикторы формирования толерантности при пищевой аллергии у детей раннего возраста

Despite modern achievements in child allergology, the question of evaluating tolerance formation and defining the safest time for expanding the child’s ration after an eliminatory diet remains open. This article contains the results of the authors’ own investigation concerning the practical meaning of specific immunoglobulins (sIg) class G4 as tolerance formation markers at food allergies in children. Thus, it has been found that high levels of sIgG4 are not only a favourable prognostic factor for light manifestations of food allergy, but also an index of a tolerance formation. The prevalence of high food allergy sIgG4 was statistically significantly higher in early age children from the comparison group than in patients with food allergy. Thus the authors suggest that the production of sIgG4 is a normal physiological process which hinders the development of hypersensitivity, while high levels of sIgG4 are evidence for the child’s immune system “contacting” this or that product. Clinical tolerance formation predictors define lighter clinical manifestations of food allergies, a non IgE-mediated form of food allergy and the retention of breastfeeding.Несмотря на современные достижения в детской аллергологии, вопрос об оценке формирования толерантности и определении времени наиболее безопасного расширения рациона ребенка после элиминационной диеты до сих пор остается открытым. В настоящей статье приведены результаты собственного исследования по изучению практического значения специфических иммуноглобулинов (sIg) класса G4 в качестве маркеров формирования толерантности при пищевой аллергии у детей раннего возраста. Так, выявлено, что высокие уровни sIgG4 являются благоприятным прогностическим признаком не только легких клинических проявлений пищевой аллергии, но также и показателем формирования толерантности. У детей раннего возраста из группы сравнения частота встречаемости высоких sIgG4 к пищевым аллергенам был статистически значимо выше, чем у пациентов с пищевой аллергией. В связи с этим высказывается предположение, что выработка sIgG4 является физиологическим, нормальным процессом, препятствующим развитию гиперчувствительности, а высокие уровни sIgG4 свидетельствуют о «контакте» иммунной системы ребенка с тем или иным продуктом. Клиническими предикторами формирования толерантности определены более легкие клинические проявления пищевой аллергии, ее не-IgE-опосредованные формы, а также сохранение грудного вскармливания

Strategy of control for bacterial biofilm processes

Main directions of the modern search of the antibiofilm preparations aimed at adhesive bacterial reactions, control of QS-systems, influence over bis-(3’-5’)-cyclic dimeric guanosine monophosphate (cdi-GMP), and secretory bacterial processes are analysed. Approaches for biofilm dispersal and increasing the sensitivity of biofilm bacteria to antimicrobial drugs are discussed. It is underlined that the majority of inhibitor molecules were studied in vitro or in infected mice experiments. It is prognosed that in future there will appear medical preparations which will help for fighting bacterial biofilms preventing their development and spreading in the host organism

SPECTRUM OF ANTIBIOTIC RESISTANCE AND PREVALENCE OF OXA-CARBAPENEMASES AMONG ACINETOBACTER BAUMANNII STRAINS, ISOLATED FROM PATIENTS OF SURGICAL AND REANIMATION DEPARTMENTS IN MOSCOW

Aim. Characterize spectrum of antibiotics resistance of Acinetobacter baumannii strains, isolated from patients of 8 surgical and reanimation departments of 3 medical institution of Moscow, and determine molecular-genetic mechanisms of stability of their carbapenem-resistant forms. Materials and methods. 95 strains of A. baumannii, isolated from patients of reanimation and surgical departments of Moscow in 2012 - 2014, were studied. Sensitivity of strains to antibiotics was tested phenotypically according to recommendations of EUCAST. The presence ofVIM, IMP, OXA-23, OXA-40, OXA-48, OXA-58 and NDM genes in the studied strains was determined by polymerase chain reaction in real time. Results. 86.3% of strains turned out to be non-sensitive to carbapenems, sensitive - 13.7%. 80.0% of strains were non-sensitive to gentamicin, 80.0% of strains - to netilmicin, 94.7% of strains - to ciprofloxacin, 2.1% - to colistin. 91.6% of isolates have shown non-sensitivity to members of 2 and more classes of antibiotics, 78.9% of strains - to members of 3 classes. 2 strains were panresistant, 4.2% (4/95) of the isolates were sensitive to all the classes of antibiotics. Metallo-P-lactamases were not detected. Genes of carbapenemases (OXA-23 and/or OXA-40) were detected in 85.3% (81/95) of strains, characterized phenotypically as non-sensitive to carbapenems. Conclusion. The results obtained shown an increase of resistance to carbapenems and multiple resistance in clinically significant strains of A. baumannii. Resistance to carbapenems is associated with OXA-23 and OXA-40 genes. The conclusions allow to justify perspectives of introduction of technologies of molecular-genetic testing of antibiotics resistance

sIgG4 and Other Tolerance Predictors at Food Allergy in Early Age Children

Despite modern achievements in child allergology, the question of evaluating tolerance formation and defining the safest time for expanding the child’s ration after an eliminatory diet remains open. This article contains the results of the authors’ own investigation concerning the practical meaning of specific immunoglobulins (sIg) class G4 as tolerance formation markers at food allergies in children. Thus, it has been found that high levels of sIgG4 are not only a favourable prognostic factor for light manifestations of food allergy, but also an index of a tolerance formation. The prevalence of high food allergy sIgG4 was statistically significantly higher in early age children from the comparison group than in patients with food allergy. Thus the authors suggest that the production of sIgG4 is a normal physiological process which hinders the development of hypersensitivity, while high levels of sIgG4 are evidence for the child’s immune system “contacting” this or that product. Clinical tolerance formation predictors define lighter clinical manifestations of food allergies, a non IgE-mediated form of food allergy and the retention of breastfeeding

PERTUSSIS IS COMING BACK? IMPROVEMENT OF FORGOTTEN CHILDHOOD INFECTION CONTROL

Infection that more than 60 years ago was recognized one of the leading childhood diseases that caused infant mortality, is returning. Of course, with the introduction of vaccination against pertussis in the national programs, we rarely meet severe pertussis infection in our practice, considering that vaccinating children, we protect them. But why so far is this infectious disease remains a serious problem not only in Russia but throughout the world? Several global reasons contribute to the fact that until now vaccine-preventable diseases leads to a prolonged, exhausting cough in schoolchildren, deceiving the doctors with the correct diagnosis is still a real threat to infants

Inhibitory effect of streptococci on the growth of M. catarrhalis strains and the diversity of putative bacteriocin-like gene loci in the genomes of S. pneumoniae and its relatives

Abstract S. pneumoniae is a facultative human pathogen causing a wide range of infections including the life-threatening pneumoniae or meningitis. It colonizes nasopharynx as well as its closest phylogenetic relatives S. pseudopneumoniae and S. mitis. Both the latter, despite the considerable morphological and phenotypic similarity with the pneumococcus, are considerably less pathogenic for humans and cause infections mainly in the immunocompromized hosts. In this work, we compared the inhibitory effect of S. pneumoniae and its relatives on the growth of Moraxella catarrhalis strains using the culture-based antagonistic test. We observed that the inhibitory effect of S. mitis strains is kept when a hydrogen peroxide produced by cells is inactivated by catalase, and even when the live cells are killed in chloroform vapors, in contrast to the pneumococcus whose inhibiting ability disappeared when the cells die. It was suggested that this effect may be due to the production of bacterial antimicrobial peptides by S. mitis, so we examined the genomes of our strains for the presence of bacteriocin-like peptides encoding genes. We observed that a set of bacteriocin-like genes in the genome of S. mitis is greatly poorer in comparison with S. pneumoniae one; moreover, in one S. mitis strain we found no bacteriocin-like genes. It could mean that there are probably some additional opportunities of S. mitis to inhibit the growth of competing neighbors which are still have to be discovered

MOESM1 of Inhibitory effect of streptococci on the growth of M. catarrhalis strains and the diversity of putative bacteriocin-like gene loci in the genomes of S. pneumoniae and its relatives

Additional file 1: Table S1. Details of whole genome sequencing of streptococci strains under study. Figure S1. Graphic representation of putative bacteriocin-associated clusters V and VI