Flashcards in ABXR 1 Deck (14)
-genes for antibiotic resistance (r plasmids) and genes for virulence factors
-easily transferred from host to host
-double stranded DNA
-tightly packed in nucleoid
-haploid, circular or linear
-can encode for certain antibiotic resistance and virulence factors usually within pathogenicity islands
What are conjugative plasmids vs non conjugative plasmids?
conjugative transfer from host to host within or between species
-spread of multiple antibiotic resistances
-cannot transfer themselves, but can be transferred by conjugative plasmids
-used for genetic engineering
Bacterial virus genome
RNA or DNA
-double or single stranded
-linear or circular
-can carry virulence factors
ex. diphtheria beta toxin cholera toxin ( toxin gene encoded by bacteriophage)
lytic infection vs lysogenic infection
lytic :phage replicates itself, lyses host cell, releases progeny phage
lysogenic: phage becomes latent doesn't replicate
-circularize or integrate into the host chromosome -latent genome called prophage
jump from genome to genome within the SAME cell
-major carrier of antibiotic resistance genes
-evolution of R plasmids
What are two types of transposable elements?
1. insertion sequence elements
What are insertion sequence elements?
cary only genes for transposition
1. recombinase (transposase)
2. inverted repeats
-recombinase recognition sites
-insertion into a gene causes mutation
What are transposons?
-transposable element that carries genes for
2. other functions
-genes between two insertion sequences
_multiple Insertion sequences joined
Transposon contain what genes?
Transposable bacterialphage contain wha genest?
-phage genome between two insertion sequences
-when lysogenic phage can transpose, i.e. jump from phage genome to chromosome or plasmid
conjugal transposon contain what genes?
-can also contain resistance genes
What are r plasmids?
carry multiple antibiotic resistance genes
-often encode enzymes that inactivate antibiotics or reduce permeability to antibiotics