What is macrolide inducible resistance?
What is macrolide inducible resistance?
In inducible resistance, the bacteria produce inactive mRNA that is unable to encode methylase. The mRNA becomes active only in the presence of a macrolide inducer. By contrast, in constitutive expression, active methylase mRNA is produced in the absence of an inducer.
What is the mode of action of clindamycin?
Clindamycin works primarily by binding to the 50s ribosomal subunit of bacteria. This agent disrupts protein synthesis by interfering with the transpeptidation reaction, which thereby inhibits early chain elongation.
How do you prevent clindamycin resistance?
Although clindamycin resistance is concerning, there is a solution. When we use clindamycin alone topically, even in acne, it is more likely to cause bacterial resistance. However, when we combine clindamycin with benzoyl peroxide, the chance of resistance decreases significantly.
How does erythromycin induce clindamycin resistance?
aureus with an erythromycin-inducible methylase (iMLS-B) that is encoded by a plasmid-borne gene (erm). When this methylase is induced it alters the binding site on the 23S subunit of the 50S ribosome that both erythromycin and clindamycin bind to, making both antibiotics ineffective (inducing resistance).
What is macrolide resistance?
Macrolides are bacteriostatic antibiotics and inhibit protein synthesis by binding to the 50S ribosomal subunit. The widespread use of macrolides is associated with increased macrolide resistance in S. pneumoniae, and the treatment of pneumococcal infections with macrolides may be associated with clinical failures.
What is the classification of clindamycin?
Clindamycin is in a class of medications called lincomycin antibiotics. It works by slowing or stopping the growth of bacteria.
Is Staphylococcus resistant to clindamycin?
Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) isolates with inducible clindamycin resistance (iCR) are resistant to erythromycin and sensitive to clindamycin on routine testing and inducible clindamycin resistance can only be identified by D-test.
What does a positive clindamycin resistance test mean?
Positive Inducible Clindamycin Resistance (D-test) test A flattening of the zone of inhibition around the clindamycin disk proximal to the erythromycin disk (producing a zone of inhibition shaped like the letter D) is considered a positive result and indicates that the erythromycin has induced clindamycin resistance (a positive “D-zone test”).
How are inducible clindamycin resistant isolates tested?
Isolates that demonstrate inducible clindamycin resistance (a D-zone test result positive for MLSBi) under these testing conditions should be reported as clindamycin resistant by the laboratory [ 21 ].
Does inducible clindamycin resistance interfere with the inhibition of staphylococcal toxin production?
Conclusions. There is also recent evidence that constitutive resistance to clindamycin in S. aureus prevents the inhibition of toxin production and fails to inhibit growth [ 5 ]. It is unclear whether inducible clindamycin resistance interferes with the inhibition of staphylococcal toxin production.
Is clindamycin still effective if the D-Zone test is positive?
Despite positive results for inducible clindamycin resistance, clindamycin may still be effective in some patients. The D-zone test is only standardized to detect inducible clindamycin resistance for Staphylococcus spp., S.pneumoniae, and beta-hemolytic Streptococcus.