Application of MALDI Mass-Spectrometry for Diagnostics of Particularly Dangerous Infectious Diseases: Current State of Affairs and Prospects

Mass spectrometry is a modern physical-chemical analytical method that provides for qualitative and quantitative assessment of the substance composition. It is based on pre-ionization of the atoms and molecules included into it. One of the advanced methods of ionization, due to which mass-spectrometry investigation of macromolecules has become a frequent practice, is matrix-assisted laser desorption/ionization (MALDI). The essence of it is the pulsed laser irradiation of the matter under study, mixed with the matrix. The review discusses current data on MALDI mass-spectrometry application for the performance of species-specific and genus-specific identification of microorganisms at the premises of diagnostic laboratories. Considered are the basic advantages of MALDI-TOF identification as compared to bacteriologic, immunologic, and molecular-genetic methods of assessment. Allocated is the mass-spectrometry position in the system of laboratory diagnostics of infectious diseases, including particularly dangerous ones, in the territory of the Russian Federation

Non-Specific Indication of Microorganisms in Environmental Samples

The review presents an analysis of modern methods and instruments for performing nonspecific detection of pathogenic biological agents in environmental objects. Discussed are technological characteristics of application of these methods for the detection of biological substances of protein nature in samples. The spectrum of means for non-specific PBA detection includes home-produced and foreign field devices based on protein contamination indication using various colorimetry variants. Technologies for remote and direct monitoring of environment for the presence of aerosols of biological nature are represented by hybrid lidar systems (biolidars) and biodetectors. For PBA nucleic acids tracing, the complexes based on DNA molecule binding with fluorophore with further fluorescence detection are described. Given are the examples of chemiluminescent analysis application in the developed automatic impurity detectors, as well as systems using bioluminescence. Based on the literature data analysis, put forward is a possible algorithm for indication of pathogenic biological agents when carrying out monitoring of the environment in zones of possible emergency situation occurrence and mass events holding

MALDI-TOF Mass-Spectrometry Analysis of Plague Agent Strains

Objective of the study was to demonstrate practicability of data base creation, containing reference mass-spectra of agents of particularly dangerous infections, using MALDI-TOF mass-spectrometry, by the example of plague agent strains. Materials and methods. MALDI-TOF mass-spectrometry was deployed for the obtainment of mass-spectra of ribosomal proteins from the microorganisms under investigation with the help of mass-spectrometers - Microflex LT. Results and conclusions. Carried out was comparative analysis of the obtained mass-spectra of 10 Y. pestis strains and reference spectra of Y. tuberculosis , contained in commercial data base of MALDI Biotyper 3.1 (Bruker Daltonics, Germany). Developed data base was validated in the process of identification of plague microbe strains, isolated in the territory of natural plague foci of the Russian Federation. That data base provided for correct identification of Y. pestis strains up to a species

Development of Methodological Approaches for Examination of Particularly Dangerous Infectious Diseases Agents by Means of Atomic Power Microscopy

The atomic power microscopy (APM) is used to study the cell surface structure of particularly dangerous infectious diseases agents and to carry out the morphometric analysis. APM shows similar results with scanning electron microscopy. However, its application makes it possible to avoid time-consuming and labour-intensive procedures of samples preparing for testing by fixation, dehydration and sputtering of conducting layer. Methodological approach has been elaborated for preparing and analysis of samples of agents of particularly dangerous infectious diseases by means of APM. This approach includes a selection of optimal substrate, mode of disinfection and scanning of samples

Предикторы морбидности радикальной цистэктомии и различных вариантов уродеривации: 20-летний опыт одного хирургического центра

Background. Most of serious complications of radical cystectomy (RCE) should be associated with the comorbidity of patients and the interintestinal anastomoses designed with urinary reservoirs rather than with RCE. It is relevant to identify and assess the role of predictors for morbidity of RCE and urine derivation.Objective: to search for risk factors for complications after RCE with different types of urine derivation.Subjects and methods. The immediate and late results of RCE and urine derivation were studied in 350 patients with bladder cancer. Sequential postoperative complications were additionally analyzed in chronological order in all the patients, including non-cancer ones (n = 43).Results. 43.9% of the patients had postoperative complications, if a surgeon had sufficient surgical experience; there was a preponderance of patients with mild-to-moderate complications (Clavien-Dindo grade I-II, 37.8%) unassociated with urine derivation. The patients with severe postoperative complications were 16.3%; mortality was 3.1%, which significantly correlated with surgical experience. Late (3-18 month) postoperative complications were detected in 21.4% of the patients with a preponderance of those with urine derivation-related complications (19.4). The frequency of complications due to extraintestinal versus intestinal urine derivations was significantly higher (68.1 and 49.8% (p < 0.05). During two-step surgical treatment, the patients demonstrated higher morbidity and worse survival. Extraintestinal urine derivations, continuous urinary intestinal diversion determine a less favorable prognosis compared with one-stage ortho- and heterotopic procedures. The type of urine derivation and the experience of a surgeon performing RCE are valid predictors for postoperative morbidity and independent prognostic factors of overall and cancer-specific survival, respectively. 150 operations are needed for achieving optimal surgical experience. Discussion. It is appropriate to increase the time of research reports on the results of urine derivation up to 12-18 months of a postoperative follow-up.In practice, the routine use of two-step RCE and final urine derivation and internal and/or external urine ones should be abandoned; preference should be, when possible, given to single-stage ortho- and/or heterotopic urine derivations rather than to the former.Conclusion. Extraintestinal (percutaneous puncture nephrostomy, ureterocutaneostomy), and internal (ureterosigmoanastomosis, ureterosigmorectoanastomosis, Mainz pouch II) urine derivations, two-step surgical treatment, and a surgeon’s insufficient experience are predictors for high morbidity and poor prognostic factors for survival after RCE and urine derivation.Введение. Бóльшую часть серьезных осложнений радикальной цистэктомии (РЦЭ) следует связывать с коморбидностью пациентов, межкишечными анастомозами, конструируемыми мочевыми резервуарами, а не с РЦЭ. Актуально выявление и оценка роли прогностических факторов морбидности РЦЭ и уродеривации.Материалы и методы. Изучены непосредственные и отдаленные результаты РЦЭ и уродеривации при РМП (n = 350). Выполнен дополнительный анализ последовательно возникших послеоперационных осложнений в хронологическом порядке у всех пациентов, включая пациентов с неонкологической патологией (n = 43).Цель исследования – поиск факторов риска развития осложнений после РЦЭ с различными вариантами отведения мочи.Результаты исследования. Послеоперационные осложнения при достаточном хирургическом опыте имеют 43,9 % больных, преобладают пациенты с легкими и умеренными (I–II степени по Clavien – Dindo) осложнениями не связанными с уродеривацией – 37,8 %. Пациентов с тяжелыми послеоперационными осложнениями – 16,3 %, летальность составила 3,1 %, что достоверно коррелирует с хирургическим опытом. Отсроченные послеоперационные осложнения (3–18 мес) выявлены у 21,4 % больных, среди которых преобладают пациенты со связанными с уродеривацией осложнениями – 19,4 %. Частота осложнений при внекишечных формах уродеривации достоверно выше в сравнении кишечными уродеривациями – 68,1 % против 49,8 % (p < 0,05). При двухэтапном хирургическом лечении пациенты демонстрируют более высокую морбидность и худшую выживаемость. Внекишечные формы уродеривации и отведение мочи в непрерывный кишечник обусловливают менее благоприятный прогноз в сравнении с одномоментными орто- и гетеротопическими методиками. Тип уродеривации и опыт хирурга, выполняющего РЦЭ, являются достоверными предикторами послеоперационной морбидности и независимыми факторами прогноза общей и канцерспецифической выживаемости соответственно. Оптимальный хирургический опыт достигается после выполнения 150 операций.Обсуждение. Целесообразно увеличение сроков исследовательских отчетов применительно к результатам уродеривации до 12– 18 мес послеоперационного наблюдения. В практической работе следует отказаться от рутинного применения двухэтапного выполнения РЦЭ и окончательной уродеривации, от вариантов внутренней и / или наружной уродеривации, а их использованию предпочесть, когда это возможно, одномоментные орто- и / или гетеротипические уродеривации.Заключение. Предикторами высокой морбидности и факторами неблагоприятного прогноза выживаемости после РЦЭ и уродеривации являются внекишечные формы уродеривации (чрескожная пункционная нефростомия, уретерокутанеостомы), внутренняя уродеривация (уретеросигмоанастомоз, уретеросигморектоанастомоз, Mainz pouch II), двухэтапное хирургическое лечение и недостаточный опыт хирурга.