I. Introductionto Microbiology - is.muni.cz€¦ · • Microbiology and medicine ... Parasites parasitology Protozoa protozoology ... „Introduction“ of microbe –how does it

I.Introduction to Microbiology

Veronika HoláInstitute for Microbiology

Faculty of Medicine, Masaryk Universityand St. Anne´s Faculty Hospital in Brno

VLA, spring term 2018

Topics covered in lectures

• Microbiology and medicine• Morphology and structure of bacteria• Antimicrobial therapy• Bacterial growth, growth curve• Microbes and environment, microbial tenacity • Microbial biofilm• Pathogenicity and virulence • Innate immunity• Acquired immunity (specific immunity)• Active and passive immunization• Course and forms of infection • Pathogenesis of infection• …

The complex of sciences dealing with micro-organisms important in the medicine• Pathogenic microbes causing diseases of human beings or

animals)• Microbes commonly present in healthy persons or animals -

normal microflora• Mutual relationship between microbes and their hosts (even we

need the microbes)• Relationship between microbes and the environment (including

methods how to eradicate the microbes)

Clinical microbiology• Part of medical microbiology dealing with etiology, pathogenesis

and diagnostics of infectious diseases

Medical microbiology

• Environmental microbiology (soil, water etc.)• Phytopathological microbiology (plant diseases) • Food microbiology (milk, meat, wine, beer etc.)• Other industrial microbiologies (fermentative processes,

waste water etc.)• Veterinary microbiology• …

Other microbiologies

Bacteria bacteriologyMicromycetes (moulds, yeasts) mycologyParasites parasitology

Protozoa protozoologyHelmints helmintologyArthropods entomology

Viruses virology(Algae) (algology)

General × Special microbiology

“Must‐knows” about each microbe„Introduction“ of microbe – how does it look; what does it causes, how and why; how is the infection diagnosed; how is the infection treated…

Red = very important

1. Classification and characterisation• Classification and cell type

– eukaryotic/prokaryotic cell, acellular organism, protein– Is it a bacterium, yeast, mould or protozoan?

• Morphology and staining– Is bacterium Gram-positive, Gram-negative, or does it stain in yet another way?– Is it a coccus, rod, filament, spiral?– How are the cells relatively arranged? In pairs, clumps, chains, tetrads?– Do they produce spores, capsules, granules?– Is the virus enveloped? What type of capsid does it have?– Etc.

2. Physiology, biochemistry, genetics, tenacity• Type of metabolism

– Is it aerobe/strict anaerobe (does the oxygen kill it)? – Is it resistant (robust), or delicate?

• Culture difficulties (see practicals)– How is it cultivated, how long does it grow? Common bacteria 24 hrs, T. pallidum

- uncultivable, dermatophytes - 3-4 weeks, TBC up to 12 weeks, viruses – only on living cells etc.

• Biochemistry– Has it any important biochemical property? Specific features? Is it important for

diagnostics? (Enterobacteriaceae)• Antigens

– Does it exist in one antigenic type or in several ones?– Is it important for diagnostics? (Enterobacteriaceae, streptococci)

• Genetics– If important for ATB resistance, virulence factors etc.

“Must‐knows” about each microbe

3. Pathogenicity• Which diseases or syndromes does it cause?• How are they called in Latin?• How is it manifested? (e.g. varicella-zoster virus – smallpox – rash/vesicles,

reactivation as herpes zoster in attenuated...)4. Pathogenesis

• Portal of entry, spread through the body, elimination?• How do the symptoms develop?• Which factors of pathogenicity (virulence) has it?

5. Immunity• Does it actually develop after the contact with the microbe?• Is it short-lasted, or life-long; humoral, or cellular one?

6. Epidemiology• What is the source of infection: man, animal or environment?• How is the agent transmitted?

7. Prevention, if necessary prophylaxis• Does a vaccination exist, or passive immunization?• What type of vaccine is in the use?


8. Laboratory diagnostics (see practicals)• Direct diagnostics – proof of given agents (microscopy, cultivation, antigens, NA) –

see practicals• Indirect diagnostics – proof of antibodies – see practicals• What type of sample has to be taken from the patient?

– How is it examined (indication of examination)?– If culture, does it require special growth medium?– How is the isolate determined?

• Interpretation– What is considered to be positive result?– What is the importance of such finding?

9. Treatment– What is the treatment of choice?– If it is an antibiotic, which one?


1. Which microbe is the etiological agent of given infectious disease?

2. Which microbes (bacteria, yeasts, moulds, viruses or parasites) are the most important causes of the given syndrome? • Do they differ according to e.g. the age of the patient?

“Must‐knows” about microbiology of different infectious diseases and syndromes

1. Test part2. Practical part3. Theoretical part• Questions = outline

• Three questions:

– General microbiology (Biofilm and its clinical importance)

– Special bacteriology (Streptococcus pyogenes)

– Special virology, mycology & parasitology (genus Hepatovirus)

• Written preparation is official part of the exam and is stored at the Institute

• General microbiology & etiological questions– Structured answers, choose appropriate examples

• Special microbiology– Mentioned above

How to pass the exam…

Recommended textbooks







David Greenwood, Richard Slack, Michael Barer, Will Irving: Medical Microbiology, 18th EditionChurchill Livingstone 2012, 794 p.

Patrick R. Murray, Ken S. Rosenthal, and Michael A. Pfaller: Medical Microbiology, 7th EditionSaunders 2013, 888 p.

Richard Goering, Hazel Dockrell, Mark Zuckerman, Ivan Roitt, Peter Chiodini: Mims' Medical Microbiology, 5th EditionSaunders, 2012, 580 p.


Microbiology started with Leeuwenhoek

(a) Leeuwenhoek´s drawings & charts; (b) Campylobacter rectus; (c) Selenomonas sputigena ; (d) oral cocci; (e) Treponema denticola; (f) Leptotrichia buccalis

Animacules

History of microbiology

Halacha and Bible - first „practical microbiology“ – killing for food onlyabsolutely healthy animals (removal of ill heads), separated dishes fordifferent food (prevention of transmission of microorganisms), ritual bodycleaning (clean water) etc.

Avicenna – transmission of infections by airFracastoro – transmission of infections by invisible particles in the air, or by

the contact with infected person or his belongings

I. Discovery of bacteria and protozoaAnthony van Leeuwenhoek (1632-1723)

• 1676 – observation by simple strong lenses (glass bullets)• water with algae, pepper solution, teeth plaque, saliva, blood…• discovery of bacteria (animacules) and yeasts• first description of protozoa and blood cells

II. Study of morphology• ca 200 yrs later• description and confirmation of bacterial existence• not linked with illnesses

Friedrich Muller (1730-1781)• taxonomic names of microorganisms

Christian Gottfried Ehrenberg (1795-1876)• 1838 – tract about bacterial taxonomy

Edward Jenner (1749-1823)• 1796 - „vaccination“ against variola – immunisation of humans with cow pox

virus (later used vaccinia virus)


III. Study of physiology• Origins of microbiological methodology• Microbiology formed as theoretical and experimental scientific discipline

Louis Pasteur (1822-1895)• 1857-1861 – proof of microbes as a cause of ethanol and lactic

fermentation• Proof of bacterial presence in the air• Use of broths for bacterial cultivation• Discovered aetiological agents of anthrax and other diseases• Elaborated basic methods and principles for vaccination by attenuated

cultures (anthrax, rabies)• Pasteurisation


Joseph Lister (1827-1912)• Cause of open-wound infections are microbes from the air, surgical

interventions in the carbolic acid spray

Ignaz Semmelweis (1818-1865)• Study of causes of puerperal sepses in hospitals• Prevention of spread of infections by hospital personnel – cleaning the

hands with chlorine

Robert Koch (1843 – 1910)• Described causative agents of many infectious diseases (Vibrio cholerae,

Mycobacterium tuberculosis - BK)• Introduced bacterial staining (aniline)• Described solid culture media for bacterial cultivation (agars), introduced

procedure of pure culture isolation• Discovered causality between pathogen and infectious disease –

formulation of four rules and methods for the proof of the causality –Koch´s postulates


1. The microorganism must be found in abundance in all organismssuffering from the disease, but should not be found in healthyorganisms.

2. The microorganism must be isolated from a diseased organismand grown in pure culture.

3. The cultured microorganism should cause disease whenintroduced into a healthy organism.

4. The microorganism must be re-isolated from the inoculated,diseased experimental host and identified as being identical to theoriginal specific causative agent.

Koch's postulates

I. Mečnikov (1845 – 1916) – importance of white blood cells; Nobel prize

P. Ehrlich (1854 – 1915) – chemist; chemotherapy – magic bullets (arsphenamine);Nobel prize

E. Ch. Hansen (1842 – 1909) – yeast & fermentative processes

H. Ch. Gram (1853 – 1938) 1884 – staining of bacteria in various tissues, Gram staining– one of the possible classification of bacteria

D. I. Ivanovskij – r. 1892 – discovery of Tobacco mosaic virus (first discovered virus)

A. Fleming (1881 – 1955) – 1929 discovery of antibacterial action of penicillin; Nobelprize

E. B. Chain (1906 – 1979) – together with A. Flemming described biochemical basis ofpenicillin action; described dosage; together with A. Fleming Nobel prize

S. Prusiner - r. 1987 – discovery of prions (v r. 1997 Nobel prize)

And many others…


• Paul de Kruif: Microbe hunters• Paul de Kruif: Men Against Death

Richard Preston: The Hot Zone

Attention! If you are not going to become a microbiologist, please read these books with the

extreme caution!

Further recommended literature

Questions

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[email protected]

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I. Introductionto Microbiology - is.muni.cz€¦ · • Microbiology and medicine ... Parasites parasitology Protozoa protozoology ... „Introduction“ of microbe –how does it

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