To determine the inducible or constitutive resistance profile to macrolides, lincosamides, and
streptogramins B (MLSb), the D-zone test was performed according to CLSI.
This poses a serious problem for drug therapy because the treatment options become limited to potentially toxic antimicrobials like vancomycin, teicoplanin,
streptogramins, linezolid and ceftaroline leading to increased mortality and morbidity.
We must take into account the constitutive MLSB phenotype in which an enzyme methylates the 23s rRNA, altering the receptor affinities of not only macrolides, but also lincomycins and
streptogramins (21).
Penicillin, tetracycline, macrolides,
streptogramins and sulphonamides are prominent examples (71) (Figure 2).
The resistance of enterococci in food animals is very similar to what has been described of enterococci isolated from nosocomial infections (including resistance to aminoglycosides, lincosamides, macrolides, nitrofurans, penicillins, quinolones,
streptogramins, tetracycline, and rarely vancomycin) [4].
(95) See NRDC Petition, supra note 80, at 3-4 (listing macrolides, lincosamides, penicillins,
streptogramins, tetracyclines, aminoglycosides, and sulfonamides).
aureus isolate(s) from each positive nasal swab were tested for susceptibility to the following 12 classes of antibiotics: aminoglycosides, beta-lactams, cephalosporins, fluoroquinolones, lincosamides, macrolides, oxazolidinones, rifamycin,
streptogramins, sulfonamide, nitrofuran, and tetracyclines (see Table S1).
In addition, resistance to
streptogramins may be related to the use of virginamycin, as a feed promoter combined in agriculture for animal food production [26].
Cattoir, "Molecular basis of resistance to macrolides, lincosamides and
streptogramins in Staphylococcus saprophyticus clinical isolates," International Journal of Antimicrobial Agents, vol.
Some of these genes are carriers of determinant genes to multiple antibiotics, besides the Macrolides, Lincosamides,
Streptogramins, Aminoglycosides and Tetracyclines.
As some depsipeptides form the active part of
streptogramins, an antibiotic class of compound targeting the bacterial ribosomal activity, it could be concluded that a quiescent (homoeostatic) bacterial state is unlikely to be targeted by depsipeptide-based tracers [34].