Guide to Practical Exercises in Medical Microbiology – Part II

INTRODUCTION

Guide to Practical Exercises in Medical Microbiology – Part II

Microorganisms – bacteria, viruses, fungi and protozoa colonize all ecological niches in nature. Many of them, known as saprophytes live freely in soil and water, participating in the cycle of substances in nature. Others have adapted to develop in humans, animals and plants, establishing complex relationships between them from symbiosis to parasitism.
Животът на Земята, във всички негови измерения, без микроорганизми е невъзможен. От medical гледна точка. огромна част от десетките хиляди известните видове микроорганизми са безвредни за the human body. Бактериите и гъбичките, приспособили се за развитие върху кожата и лигавиците на човешкото тяло са безвредни за здравия организъм. Тези около 500 вида съставляват неговата нормална флора (microbiota) and play an irrevocable role in the physiological processes of the body with their antagonistic action towards other pathogens, participation in metabolic processes and stimulating the development of the immune system and the immune response during the infectious process.
Some types of microorganisms that have adapted to the human body, during their development damage physiological processes. They are known as pathogenic microorganisms and are not part of the normal flora. After infection with them, they temporarily reside in tissues and organs. Depending on the body's protective reactions, they carry out different forms of the infectious process - from an inapparent (unmanifested) infection, to mild and severe lethal forms of the infectious disease. Depending on their source and reservoir, a number of pathogenic microorganisms spread epidemically between people or between animals and people.
In individuals with weakened protective reactions (after trauma, burns, cancer and other severe chronic diseases, drug addictions), pathogenicity can also manifest itself. non-pathogenic microorganisms - saprophytes from the environment and more often bacteria and fungi from the normal flora, known in this capacity as conditionally pathogenic or opportunistic microorganisms. Disturbances in the balance of species from the normal flora, known as dysbiosis, as a result of frequent irrational use of antibiotics or prolonged treatment with cytostatics and immunosuppressants, to suppression of immune responses and manifestation of pathogenicity by microorganisms that have developed in excessively large quantities.
Познаването на микроорганизмите, причинители на infectious diseases в човека – патогенните и условно патогенните е от голямо значение за медицинската практика. Инфекциозните заболявания са водещи в човешката pathology and as a cause of the lethal outcome. In specifying the etiology and treatment of infectious diseases, microbiological diagnostics and knowledge of the possibilities of the diagnostic methods used in it are of leading importance.
The positive effect of microbiological diagnostics can be expected only if the clinical and laboratory staff are familiar with the rules for taking and transporting clinical material, the nature of diagnostic methods and the assessment of the pathogenic potential of the proven microorganisms. The determination of the antibiotic sensitivity of the isolated bacteria and fungi is a guarantee for the rational use of antibiotics to limit the increasingly widespread drug resistance among infectious agents.
This manual for practical exercises in medical microbiology is intended for students of medical universities. The aim of the thematic material is for students to gain knowledge on bacterial and viral pathogens and the classical and modern molecular diagnostic methods used in daily clinical practice to clarify the etiology of infections and provide guidelines for the rational use of antimicrobial drugs.