Antibiotic resistance Flashcards
what are the two ways that acquired resistance can occur?
Mutation and clonal expression ( spotatneous)
Transferable resistance
How does transferable resistance occur?
Sharing of genetic material is a much faster means of spreading resistance genes than spontaneous mutation
What are the different mechansims of resistance
Altered target site for the antimicrobial
Enzymatic degradation of antimicrobial agents
Alteration of uptake of output of antimicrobial agents
What does the enzyme betalactamase
enzyme which hydrolyses the beta lactam ring
mode by bacteria to protect itself against a beta lactam antibiotic
what is the mechanism of resistance for Methicillin Resistant Staphylococcus Aureus MRSA
altered target site
What is the mechanism of resistance for Gylcopeptide Resistant Enterococcus (GRE)
altered target site
what is the mechamis of resistance of Carbapenemase Producing Enterobacteriaceae (CPE)
enzymatic degradation
what is the mechanism of resitance for Multi-Drug Resistant Tuberculosis (MDR- TB)-
intrinsic and acquired through mutation
how is MRSA resistant
MEC A gene mutation
altered penicillin binding protein
beta lactams fail to bind
creates MRSA phenotype
how is GRE resistant
glycopeptides bind to the peptidoglycan precursor molecule and prevent their incorporation into the cell wall
altered precursor molecule prevent the glycopeptide from binding
can be endemic in healthcare environments
what is carbapenase
an Enzyme made by an Enterobacteriaceae that destroys these antibiotics
how are pseaudomonas aeruginose resistant
Intrinsic resistance
highly adaptable
how is myobacterium TB
intrinsic resistance duet to part lipid cell wall
rapidly develops resistance on treatment
slow growing organism
What does the CD4 t-helper lymphocyte do
central in immune response to TB - infected and depleted by HIV
What kind of patients are likely to get infections involving antibiotic resistance
Exposure to healthcare - those with chronic conditions
Exposure to antibiotics - chronic infective conditions
