You decide if the examination will be held in Danish or in English. Censor is Dr. Peter Westermann, BioCentrum, Technical University of Denmark.

Transkript

1 Advanced Bacteriology 2007 Questions for final exam The final exam will take place Thursday November in Øvelsessal II, Sølvgade 83H (Øvelsessal II is found behind Øvelsessal III where teaching took place). Each of you will receive a separate stating the time of your examination. At the start of the examination you will draw one of the following questions (numbered 1 through 18) and is expected to do a talk based on the question. The talk should last between five and ten minutes, and you may accompany the talk with up to two overhead slides (for technical reasons we will not accept PowerPoint presentations). After your talk, the examinator with ask you questions related to the question drawn or questions related to the curriculum of the course expect that about 30% of our questions will be related more to the general curriculum than to the specific question drawn. You decide if the examination will be held in Danish or in English. Censor is Dr. Peter Westermann, BioCentrum, Technical University of Denmark. If you have any questions please contact me or any of the teachers at the course. Anders Priemé

2 1) Beskriv de metoder, der anvendes til identifikation eller typning af bakterier. Redegør for fordele og ulemper ved metoderne. Gør desuden rede for hvorfor typning af patogene bakterier kan være relevant. 1) Describe the methods used for identification or typing of bacteria. Explain the advantages and disadvantages of the different methods. Also, explain why typing of pathogenic bacteria may be relevant.

3 2) Forskellige bakterier har permanent eller midlertidigt ophold i menneskets mavetarmsystem. Beskriv disse bakteriers forskellige roller i forhold til deres menneskevært. 2) Describe the different roles played in the life of a human by permanent and transient bacteria in the human gastrointestinal tract.

4 3) Beskriv de tilpasninger som psychrofile bakterier udviser til liv ved lav temperatur og de tilpasninger alkalifile bakterier udviser til liv ved høj ph. 3) Describe the mechanisms used by psychrophilic bacteria to cope with life at low temperature and the mechanisms used by alkaliphilic bacteria at high ph.

5 4) Beskriv de virulensfaktorer, som Campylobacter jejuni anvender ved infektion af mennesker. 4) Describe the virulence factors used by Campylobacter jejuni to cause disease in humans.

6 5) Beskriv de virulensfaktorer, som Staphylococcus aureus anvender ved infektion af mennesker. 5) Describe the virulence factors used by Staphylococcus aureus to cause disease in humans.

7 6) Giv med udgangspunkt i figuren en redegørelse for hvilke naturlige genopsamlings- og ekspressionssystemer, der findes i bakterier. Hvilke typer af gener er oftest blevet fundet i disse systemer og afspejler dette fordelingen af generne i naturlige ikke-forurenede miljøer? 6) Which kinds of naturally occurring gene capture and expression systems are found in bacteria (explain the figure). Which types of genes have most often been associated with these systems and does this reflect the distribution of genes in natural nonpolluted environments? P C IntI1 orf1 orf2 orf3 P int atti 59-be 59-be 59-be

8 7) Beskriv med udgangspunkt i figuren, hvorledes forskellige plasmider initierer replikationen, samt hvilke mekanismer plasmider benytter sig af til reguleringen af replikationen (kopi tals regulering). 7) Describe how different plasmids initiate replication (starting with the figure below) and what mechanisms plasmids use for regulating replication (copy number control). 1A. initiation 1B. Inhibition of initiation

9 8) Beskriv hvilke forskellige forholdsregler plasmider kan benytte sig af for at undgå at blive tabt fra en bakteriekultur. 8) Describe what different mechanisms plasmids can use to avoid elimination from a bacterial culture.

10 9) Lav en beskrivende gennemgang af en generel opbygning af et stort plasmid som du ville forvente at det så ud hvis det var isoleret ved eksogen plasmid isolering, fra hospitals spildevand. Beskriv forskellige metoder til at isolere store plasmider fra spildevand. 9) Describe the general composition of a large plasmid, as you would expect it to look like, had it been isolated by exogenous plasmid isolation from hospital sewage. Describe different methods to isolate large plasmids from waste water.

11 10) Hvilke gener er typisk knyttet til kendte plasmider? Hvordan kan man undersøge om det forholder sig således i naturen? Opstil en hypotese over hvordan plasmider er opstået og hvad de koder for i naturlige miljøer. 10) Describe which genes are typically associated with known plasmids? How can it be investigated, if the same genes are plasmid accociated in nature. Present a hypothesis on how plasmids have evolved and what they encode in natural environments.

12 11) Forklar nedenstående figur og drag sammenligninger til AHL-medieret quorum sensing hos Gram negative bakterier. 11) Explain the figure and compare it with the AHL-mediated quorum sensing in Gram negative bacteria

13 12) Forklar, med udgangspunkt i nedenstående figur, hvorledes quorum sensing indgår i reguleringen af virulens-faktorer hos Vibrio cholerae. 12) Use the figur to explain how quorum sensing is involved in regulation of virulence in Vibrio cholerae

14 13) Beskriv forskelle og ligheder på quorum sensing i Gram positive og Gram negative bakterier. 13) Describe differences and similarities between quorum sensing in Gram positive and Gram negative bacteria

15 14) Diskuter fordele for bakterier ved at etablere biofilm, og redegør for hvordan bakterier kan tilpasse sig livet i biofilm. 14) Discuss advantages for bacteria in biofilm formation, and give examples on how bacteria adapt to life in biofilm.

16 15) Diskuter med udgangspunkt i nedenstående figur co-evolution og synegistiske effekter i flerarts biofilm. 15) Use the figure as starting point for a discussion on co-evolution between bacteria and synergistic effects in multi-species biofilms.

17 16) Beskriv forskellen mellem prospektive og retrospektive studier af horisontal genoverførsel og diskuter fordele og ulemper ved de to metoder. 16) Describe the difference between prospective and retrospective studies of horizontal gene transfer and discuss pros and cons of the methods.

18 17) Redegør for de faktorer der begrænser omfanget af horisontal genoverførsel mellem bakterier i naturlige miljøer, og diskuter betydningen af horisontal genoverførsel for artsbegrebet hos bakterier. 17) Describe the limiting factors for horizontal gene transfer between bacteria in natural environments, and discuss the consequences of HGT on the species concept for bacteria.

19 18) Beskriv hvordan bakterier kan tilpasse sig græsning af protozoer, og diskuter konsekvenser af sådanne tilpasninger hos potentiel patogene bakterier. 18) Describe how bacteria adapt to protozoan grazing, discus the consequences of such adaptations in opportunistic pathogenic bacteria.