Lyudmila Kraeva – Head of laboratory, Doctor of Medicine
Tel.: (812) 232-94-85, (812) 498-09-39, room 243
The laboratory works on the advance of the microbiological diagnostics of diseases caused by Yersinia, Corynebacteria, Bordetella and other microorganisms that have medical significance.
The Laboratory of Medical Bacteriology began its work in 2016 on the base of the Laboratory of Airborne Bacterial Infections created in April 1993 because of the massive diphtheria epidemic. Many years of research by the Laboratory scientists were aimed at obtaining modern ideas about the basic biological properties of bacteria, the mechanisms of their interaction with the macroorganism, immunogenesis, diagnosis and prevention of diseases.
The Laboratory staff carry out research on the strains of Y. pseudotuberculosis, Y. enterocolitica and other representatives of the genus Yersinia. The potential ability of the representatives of Yersinia species, considered to be non-pathogenic (Y. enterocolitica biotype 1A, Y. kristensenii) to cause a pathological process was demonstrated. Sequencing is used for in-depth study of the different types of Yersinia. The application of the MALDI TOF method of mass spectrometry made it possible to improve the identification quality of closely related Y. enterocolitica representatives of the genus Yersinia. Since 2008, on the basis of the laboratory, Rospotrebnadzor ordered to establish the Reference Center (RC) of monitoring of the yersinioses.
20 years after the epidemic of diphtheria in Russia, the peak of which occurred in the 90s. of the XX century, against the background of the decreased incidence, the vigilance of clinicians regarding the infection is increasingly lost. Therefore, the staff of the Laboratory developed new methodological approaches, criteria and methods for evaluating the protection from diphtheria. To speed up the detection of toxigenic strains of C. diphtheriae in the laboratory, a method for determining potentially toxic strains of the diphtheria pathogen using low-intensity laser radiation was proposed. For the purpose of registering such strains, a diagnostic kit and a microreader based on micro- and nanotechnologies have been developed.
Pertussis remains a serious public health problem despite more than 50 years of vaccine-preventive maintenance. The Laboratory studies the strains of Bordetella pertussis and B. parapertussis by molecular-genetic methods (pulse field electrophoresis, sequencing) to control the variability of the circulating population of the pathogen. Another problem studied by the Laboratory is the formation of the post-vaccination anti-pertussis immunity, its intensity and duration.
In recent years there has been an increase in the frequency of the discharge of Moraxella catarrhalis in case of the acute inflammatory processes in the airways, especially in the development of complications after a viral infection. Employees of the Laboratory developed an algorithm for studying the material from patients with the aim of improving the tactics of the therapy for acute inflammatory diseases of the respiratory tract caused by M. catarrhalis.
The greatest difficulty in the work with conditionally pathogenic bacteria is the definition of the etiological role of isolated microorganisms. A study of the presence of virulence genes in strains of S. epidermidis and streptococci (S. oralis, S. anginosus, S. mitis) was conducted during the studies. The combination of genetic and phenotypic methods for revealing the pathogenic properties of bacteria makes it possible to increase the reliability of the laboratory studies and to improve the quality of the prescribed therapy.
In order to significantly reduce the time of the bacteriological research, a miniature version of the classical bacteriological method "laboratory-on-chip" is being developed in the Laboratory. To implement this project, we are using the modern achievements of nano- and microtechnologies. The database of visual images of microcolumns includes more than 3000 images of 45 species of the bacteria. A full cycle of bacteriological research, including time to determine the relationship to antibiotics, is no more than 6-7 hours.