Macrolide resistance

Other examples include rifampin resistance due to mutations in the ipoB gene encoding the (3-subunit of RNA polymerase, or oxazolidinone resistance due to a G2576T mutation in the gene for the 23 S rRNA as central part of the 50S large ribosomal subunit. Macrolide resistance is based upon the alteration of nucleotide A2058 by a point mutation. 

O-phosphotransferases that modify macrolides are produced by highly macrolide resistant E. coli isolates. However, these enzymes have no clinical importance for macrolide resistance in gram-positive bacteria, and gram-negative ones are regarded as naturally resistant [2]. 

Pharmacokinetic/pharmacodynamic modeling indicates that the AUC/MIC ratio is predictive of outcome for this antibacterial suggesting that telithromycin is suitable for short-duration therapy and a once-daily dosing regimen even against / -lactam and macrolide-resistant pathogens... 

Zhanel GQ Hisanaga T, Nichol K, Wierzbowski A, Hoban DJ. (2003) Ketolides An emerging treatment for macrolide-resistant respiratory infections, focusing on S. pneumoniae. Expert Opin Emerg Drugs 8 297-321. 

S pneumoniae, S aureus, H influenzae, Moraxella catarrhaiis, mycoplasmas, Legionella, Chlamydia, H pylori, N gonorrhoeae, fragilis, T gondii, and nontuberculosis mycobacteria. Many macrolide-resistant strains are susceptible to ketolides because the structural modification of these compounds renders them poor substrates for efflux pump-mediated resistance and they bind to ribosomes of some bacterial species with higher affinity than macrolides. 

Taniguchi, K. Nakamura, A. Tsurubuchi, K. Ishii, A. O Hara, K. Sawai, T. Appearance in Japan of highly macrolide-resistant Escherichia coli producing macrolide 2 -phosphotransferase IL Microbios, 97, 137-144 (1999)... 

R Okamoto, H Nomura, M Tsuchiya, H Tsunekawa, T Fukumoto, T Inui, T Sawa, T Takeuchi, H Umezawa. The activity of 4"-<9-acylated tylosin derivatives against macrolide-resistant Gram-positive bacteria. J Antibiot 32 542-544, 1979. 

M Tsuchiya, T Sawa, T Takeuchi, H Umezawa, R Okamoto. Binding of 3-O-acetyl-4 "-O-iso valery I tylosin to ribosomes from a macrolide-resistant strain of Staphylococcus aureus. J Antibiot 35 673-679, 1982. 

M Tsuchiya, M Hamada, T Takeuchi, H Umezawa, K Yamamoto, H Tanaka, K Kiyoshima, S Mori, R Okamato. Studies of tylosin derivatives effective against macrolide-resistant strains synthesis and structure-activity relations. J Antibiot 35 661-672, 1982. 

B Schoner, M Geistlich, P Rosteck Jr, RN Rao, E Seno, P Reynolds, K Cox, S Burgett, C Hershberger. Sequence similarity between macrolide-resistance determinants and ATP-binding transport proteins. Gene 115 93-96, 1992. 

Moxifloxacin has a broad spectrum of activity which includes Gram-positive cocci, atypical pathogens and anaerobic bacteria responsible, inter alia, for infections of the respiratory tract. Moreover, moxifloxacin is one of the most effective fluoroquinolones against pneumococci, including the penicillin- and macrolide-resistant strains. The development of resistance to moxifloxacin is slower than that of the other fluoroquinolones. 

Maravic G. Macrolide resistance based on the Erm-mediated rRNA methylation. Curr. Drug Targets Infect. Disord. 2004 4(3) 193-202. 

Portillo A, Lantero M, Gastanares MJ, Ruiz-Larrea F, Torres C. Macrolide resistance phenotypes and mechanisms of resistance in Streptococcus pyogenes in La Rioja, Spain. Int J Antimicrob Agents 1999 13(2) 137 0. 

Cellesi C, Rossolini GM. Patterns of macrolide resistance determinants among community-acquired Streptococcus pneumoniae isolates over a 5-year period of decreased macrolide susceptibility rates. Antimicrob Agents... 

Melo-Cristino J, Fernandes ML. Streptococcus pyogenes isolated in Portugal macrolide resistance phenotypes and correlation with T types. Portuguese Surveillance Group for the Study of Respiratory Pathogens. Microb Drug Resist 1999 5(3) 219-25. 

De Azavedo JC, Yeung RH, Bast DJ, Duncan CL, Borgia SB, Low DE. Prevalence and mechanisms of macrolide resistance in clinical isolates of group A streptococci from Ontario, Canada. Antimicrob Agents Chemother 1999 43(9) 2144-7. 

Varaldo PE, Debbia EA, Nicoletti G, Pavesio D, Ripa S, Schito GC, Tempera G. Nationwide survey in Italy of treatment of Streptococcus pyogenes pharyngitis in children influence of macrolide resistance on clinical and microbiological outcomes. Artemis-Italy Study Group. Clin Infect Dis 1999 29(4) 869-73. 

S. pneumoniae resistance is increasing because the incidence of macrolide resistance is approximately Despite these... 

Another worrisome trend is the increased in vitro resistance reported for many gram-positive bacteria. Of greatest concern is the increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA). Treatment choices for SSTIs have been further complicated by the increased incidence of macrolide-resistant strains of S. aureus and S. pyogenes ... 

Clindamycin binds exclusively to the 50S subunit of bacterial ribosomes and suppresses protein synthesis. Although clindamycin, erythromycin, and chloramphenicol are not structurally related, they act at sites in close proximity, and binding by one of these antibiotics to the ribosome may inhibit the interaction of the others. There are no clinical indications for the concurrent use of these antibiotics. Macrolide resistance due to ribosomal methylation by encoded enzymes also may produce resistance to clindamycin. However, because cUndamycin does not induce the methylase, there is cross-resistance only if the enzyme is produced con-stitutively. Clindamycin is not a substrate for macrolide efflux pumps thus, strains that are resistant to macrolides by this mechanism are susceptible to clindamycin. Altered metabolism occasionally causes clindamycin resistance. 

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