AIMS AND LEARNING OUTCOMES

Attending and participation in the planned activities will allow students to acquire the basic knowledge on the biology of microorganisms, their role in nature and the different applications in health, industrial and environmental fields. Specifically, students will be able

• to know the morphological, physiological, genetic and metabolic characteristics of microorganisms

• to know the distribution and role of microorganisms in the environment

• to know their interactions with other organisms including those leading to host damage

• to understand the mechanism of action of antimicrobials and molecular basis of microbial resistance

• to know applications of microorganisms and their products in health, industrial and environmental fields

• to apply the basic techniques for cultivation, analysis and identification of microorganisms in the laboratory

The course will provide the basis for further specialized studies in the field of molecular, environmental, food and health microbiology

PREREQUISITES

Prerequisites are not needed but for a profitable and easy study of the discipline it is advisable to have acquired knowledge on organic chemistry, biological chemistry and molecular biology

TEACHING METHODS

The “Microbiology and laboratory” course is composed by both lectures (7 cfu) and a part of practical laboratory (1 CFU). Attendance at lessons is strongly recommended. Lectures in the classroom are delivered through multimedia presentations.

Attendance at the laboratory is mandatory. The laboratory exercises are aimed at the practical application of the knowledge acquired during the lectures. In particular, topics will be covered concerning the cultivation and staining of bacteria, their identification by biochemical tests, the evaluation of the concentration of bacteria and viruses in biological samples, the assessment of the sensitivity of bacteria to chemical and physical agents.

 The laboratory exercises take place in a laboratory equipped with microscopes and all instruments needed for performing all the tests

SYLLABUS/CONTENT

The following topics will be presented and discussed:

INTRODUCTION TO MICROBIOLOGY

• The world of microorganisms.
• History of Microbiology
• Evolution and microbial systematic

BACTERIA

• Morphology and size. Bacterial stains

• Structure and functions of the bacterial cell: cytoplasm and its contents; nucleoid; cytoplasmic membrane; cell wall; glycocalyx; flagella; pili and fimbriae; endospore

• Nutrition and energy reactions.

• Bacterial division

• Factors influencing bacterial growth and evaluation of  growth

• Culture media and bacterial cultivation.

• Biofilm

• Ecological role of bacteria and biogeochemical cycles.

• Bacterial interactions

• Culture-independent assays to study bacteria

ARCHAEA

• Structure and functions of the cell.

• Diversity and ecological role

EUKARYOTIC MICROORGANISMS

• Structure and functions of the eukaryotic cell and biodiversity

VIRUSES

• Chemical composition and structure.

• Classification

• Cultivation and evaluation of their concentration

• Characteristics of the viral infectious cycle.

• Lytic and lysogenic cycle of bacteriophages.

• Replication of DNA and RNA animal viruses.

• Cytopathic effect and principles of pathogenesis of viral infections

• Virus-like particles: viroids

BACTERIAL GENETICS

• The bacterial genome: core and pool of flexible genes.

• Plasmids and other mobile elements

• Horizontal gene transfer (transformation, transduction, conjugation) and its role in bacterial evolution

BACTERIAL PATHOGENICITY AND VIRULENCE

• Indigenous microbiota / microbiome; opportunism.

• Main steps of the pathogenic process and involved bacterial factors: adhesion, colonization, epithelial cell invasion, dissemination, resistance to phagocytosis, damage to the host (exo and endo toxins).

ANTIBACTERIAL AND ANTIVIRAL STRATEGIES

• Historical background
• Disinfection and sterilization

• Antibacterial drugs: antibiotics and other chemotherapeutics, selective toxicity, spectrum of activity, mechanism of action.

• Bacterial resistance to antibiotics: genetic bases and biochemical mechanisms.

• Antiviral drugs and interferon

• Vaccines: background, old and new-generation vaccines

APPLIED MICROBIOLOGY

• Historical background on the use of microorganisms for the production of goods and services

• Microbiology and biotechnology

• Fermentation, bioreactors, control and monitoring of fermentation, "scale up" process.

• Primary and secondary metabolites.

• Main products of industrial microbiology (amino acids, organic acids, polysaccharides, enzymes, antibiotics, microbial cells)

• Bioconversions.

LABORATORY

• Preparation of culture media for bacteria

• Microscopic observation of bacteria stained with Gram staining

• Cultivation of bacteria in pure culture

• Isolation of a bacterial strain and identification based on the analysis of the biochemical profile

• Quantification of culturable bacterial cells present in a sample (determination of colony forming units and evaluation of the "most probable number")

• Assessment of bacterial sensitivity to antibiotics by Kirby-Bauer test and evaluation of MIC ( minimum inhibitory concentration) and MBC (minimum bactericidal concentration)

• Evaluation of the sensitivity of a mesophilic bacterial strain (Escherichia coli as a model organism) to high temperature exposure

• Assessment of the host range of a bacteriophage

• Quantification of the number of viral particles present in a suspension by the method of the plaque-forming units (bacteriophage T7 as a model virus)

RECOMMENDED READING/BIBLIOGRAPHY

All slides used during lessons and other teaching materials will be available on AulaWeb or will be provided by the teachers at the end of each lesson cycle. The books below are suggested as supporting texts, but students can use other university level texts.

-"Brock - Biologia dei microrganismi. Microbiologia generale, ambientale e industriale"  M.T. Madigan, J.M. Martinko, K. S. Bender, D.H. Buckley, e D.A. Stahl  (2016) e "Brock - Biologia dei microrganismi. Microbiologia biomedica” M.T. Madigan, J.M. Martinko, D.A. Stahl  e D.P. Clark (2012). Pearson Education

-“Biologia dei microrganismi”  G. Deho ed E. Galli  (2014) Casa Editrice Ambrosiana