Molecular and Cellular Mechanisms of Bacterial Pathogenesis


This curricular unit will provide competences in the understanding of molecular and cellular aspects of bacterial infections, in particular on the interplay between bacterial pathogens and eukaryotic host cells. This implies the acquisition of knowledge on mechanisms underlying bacterial virulence, and on the methods used to study it, as well as the acquisition, or strengthening, of knowledge on eukaryotic cell biology and on immunology. Upon completion of this curricular unit, the students should be able to: i) know the general mechanisms used by bacterial pathogens to resist host cell defences; exemplify host cell processes and molecules that are manipulated by bacterial virulence proteins; iii) understand experimental data related to microbe-host cell interactions.

General characterization





Responsible teacher

Luís Jaime Gomes Ferreira da Silva Mota


Weekly - 4

Total - 43

Teaching language



Available soon


Cellular Microbiology, P. Cossart, P. Boquet, S. Normark, R. Rappuoli (Eds), American Society of Microbiology 2nd edition, 2004.

Bacterial Pathogenesis: a Molecular Approach, B. A. Wilson, A. A. Salyers, D. D. Whitt, and M. E. Winkler, American Society of Microbiology, 3rd edition, 2010.

Cellular and Molecular Immunology, A. K. Abbas, A. H. Lichtman, S. Pillai, Elsevier, 6th edition, 2007.

Selected review articles covering the topics presented in the lectures (provided by the lecturers).

Teaching method

The curricular unit is organized in lectures and labs. The lectures will be presented by data-show and will be mostly based on research and review articles. The labs, where the students will work in groups, will be based on methods used to study structures and proteins at the bacterial surface enabling resistance to host defense mechanism, and the mechanism of protein secretion (using non-pathogenic strains). In the labs, the students will also be helped to solve problems based on experimental data sets. The evaluation of the learning objectives will be continuous through 2 tests (focused on the lectures and practical sessions) during the semester, and by an evaluation of a project, which will consist in the presentation of research articles (by groups of students). The students must be present at a certain number of laboratory sessions and must attend the presentation of the seminars; otherwise, they will fail in the curricular unit and will be excluded from the final exam.

Evaluation method

The continous evaluation will be divided into:

- 1 written test based on the lectures and labs (75% of the final mark; minimal classification of 9.5)

- Presentation of seminar (15 min, plus 5 min discussion, in groups of 2 students) (25% of the final mark; minimal classification of 10 for final approval at the curricular unit)

Conditions for approval at the curricular unit:

- Final mark of 10.

Other conditions for approval and to be accepted at the final Exam:

- Presence in at least 2/3 of the lab (at least 4 out of 6).

- Presentation of the seminars and attendance of all seminars.

- When these conditions are achieved, they will still be valid for the subsequent curricular year.

Calculation of the final mark:

- The final mark will be the weighted average of the evaluation components, as indicated above. For this calculation, the marks of each element of evaluation will be to the first decimal and the final mark will be rounded to nearest integer. 

Final exam:

 - There will be an additional final exam for students that fail in the first exam (test) or that want to improve their mark. 

Subject matter

Overview of bacterial pathogenesis: host defences and countermeasures deployed by the bacteria. Identification of different infection models frequently used in bacterial pathogenesis. Definition of virulence factors and how they are identified. Mechanisms of gene transfer in bacteria and selection of strains with different capacity to cause disease. Recent cases associated with outbreaks by certain bacterial strains. General bacterial mechanisms of avoidance or resistance to host defences - the example of Gram-positive bacteria such as Staphylococcus or Pneumococcus. Actin cytoskeleton and its manipulation by bacterial pathogens; examples of intracellular motility, invasion and anti-phagocytosis by bacterial pathogens. Vesicular transport and its manipulation by bacterial pathogens: proteins and lipids involved in vesicular transport; examples of rupture and release from the phagosome, of subversion of the phagolysosomal pathway and of survival within a phagolysosome.


Programs where the course is taught: