Antibiotic Resistance Flashcards
“Episome” is another name for a _______.
plasmid
What is the difference b/t conjugative and non-conjugative plasmids?
Conjugative plasmids autonomously transfer from host to host within or between species, whereas non-conjugative plasmids cannot transfer themselves but CAN be transferred by conjugative plasmids.
What is a major cause of spread of multiple antibiotic resistances?
conjugative plasmids
What is the average size of a bacterial genome?
megabases large! (~4000 genes)
What are the alternative names for chromosomal genomes, plasmid genomes, and bacterial virus genomes?
bacterial, episome, and phage, respectively
Certain bacterial genomes are capable of autonomously transferring themselves from one host to another, either within the same species, to other species, or to other generas. Bacterial genomes capable of this form of self-transfer are called:
conjugative plasmids
Which pathogens use transformation as a mode of genetic exchange?
Strep. pneunomiae, Haem. influenzae, N. gonorrhea
What is a way to block transformation?
nucleases and detergents (chop up naked DNA)
What is a way to block conjugation?
vigorous shaking (vortexing)
What is the mechanism by which bacteria induce genes for competence?
quorum sensing
What are 3 fates of the exogenote?
- degraded (by nucleases)
- circularized (lost by dilution)
- recombined (stably retained)
Is it possible for an entire genome to be transferred via conjugation?
Yes, if a plasmid combines with a chromosome; the entire unit could be transferred from donor to recipient via conjugation.
What are the 2 major reasons why conjugation is clinically relevant?
1) Rapid dissemination of drug resistance (via conjugal R plasmids or conjugal transposons)
2) Mediates inter-species transfer from non-pathogenic to pathogenic
What acts as a resistance reservoir?
normal flora (normal, non-pathgenic flora may transfer resistance genes to pathogenic bacteria)
What is the vector of transduction?
bacteriophage
