Not a mechanism of resistance to erythromycin?
Ans. is 'None > c' i.e., Erythromycin esterase production o All are true. Mechanism of drug resistance for erythromycin o Bacterial resistance to erythromycin occurs by: (i) Target site alteration (alteration in the 505 ribosomal binding site by methylation) by enzyme methylase which is encoded by plasmid -4 Most common (ii) Altered transpo with active efflux to pump it out by efflusx protein --> 2nd most common (iii) Drug modification by enzyme, i.e. erythromycin esterase rare o Mechanisms (i) and (ii) are the most common mechanisms for bacterial resistance to erythromycin o Resistance may be chromosomal mediated or plasmid mediated and it may be inducible or constitutive. o Resistance to erythromycin implies resistance to all macrolides. Coming back to question o Most appropriate answer of this question is None. o However, if the question is repeated as such go ahead with option 'c' because: 1. Two most common mechanism for erythromycin resistance are: (i) Alteration in ribosomoal binding side (option a) by plasmid encoded (option b) methylase (ii) Active efflux of drug by efflux protein (option d) 2. Production of erythromycin esterase is an uncommon mechanism for erythromycin resistance.
Alteration in ribosomal binding site
Plasmid mediated
Erythromycin esterase production
Efflux proteins