In VitroActivity of Tedizolid Compared to Linezolid and Five Other Antimicrobial Agents against 332 Anaerobic Isolates, Including Bacteroides fragilis Group,Prevotella,Porphyromonas, andVeillonellaSpecies

Abstract

<jats:p>Tedizolid's anaerobic activity is unappreciated; it was active against all 332 anaerobic isolates at ≤2 μg/ml except <jats:italic>Bilophila wadsworthia,</jats:italic> and was more active than linezolid against <jats:italic>B. fragilis group</jats:italic> sp. (MIC<jats:sub>90</jats:sub> 1 μg/ml vs 2-4 μg/ml). Tedizolid was active against Gram-positive anaerobes (MIC<jats:sub>90:</jats:sub> clostridia 0.25-1 μg/ml; anaerobic cocci ≤0.06 – 0.25 μg/ml). Coupled with clinical reports, clinicians should consider its use in mixed infections where <jats:italic>S. aureus</jats:italic> and anaerobes are involved.</jats:p>

In Vitro Antimicrobial Susceptibility Profiles of Gram-Positive Anaerobic Cocci Responsible for Human Invasive Infections

“…GPAC are usually susceptible to antibiotics used to treat anaerobic infections but increasing resistance trends have been reported and major differences between species of GPAC have been observed [ 1 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. In addition, most AST reports until recently presented data for GPAC as a group rather than for individual species [ 1 , 15 , 28 , 29 , 30 , 31 , 32 ].…”

“…Most evidence suggests that F. magna , P. micra and P. harei are almost always susceptible to penicillins [ 16 , 17 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 31 , 33 ]. By contrast, strains of P. anaerobius usually present higher MIC values and some of them are highly resistant with MICs of amoxicillin up to 16–64 mg/L [ 16 , 17 , 19 , 26 , 27 , 33 ]. In our study, MICs of amoxicillin and piperacillin were also up to 64- and 256-fold higher for P. anaerobius than those for other species, respectively ( Table 1 ).…”

“…In the literature, no acquired high-level resistance to vancomycin (MIC 50 = 0.06–1 mg/L; MIC 90 = 0.25–1 mg/L) or to linezolid (MIC 50 = 0.5–4 mg/L; MIC 90 = 0.5–4 mg/L) has been reported so far [ 15 , 18 , 21 , 23 , 24 , 26 , 27 , 30 , 31 , 35 , 41 ]. In our study, three strains of P. micra exhibited an MIC of 4 mg/L and were categorized as resistant but they are probably part of the wild-type population, as previously described [ 31 ].…”

“…Most evidence suggests that F. magna, P. micra and P. harei are almost always susceptible to penicillins [16,17,[19][20][21][22][23][24][25][26][27][28][29]31,33]. By contrast, strains of P. anaerobius usually present higher MIC values and some of them are highly resistant with MICs of amoxicillin up to 16-64 mg/L [16,17,19,26,27,33].…”

Pharmacokinetics and Pharmacodynamics of Tedizolid

“…The intracellular penetration can be potentially exploited to treat intracellular pathogens [66]. Its moderate activity against anaerobes particularly against Bacteroides fragilis (MIC 90 of 1 mg/L) can be exploited to treat mixed aerobic and anaerobic infection [67]. Tedizolid expresses good activity against several clinically relevant respiratory pathogens such as PRSP (MIC 90 of 0.25 mg/L) and PSSP (MIC 90 of 0.125-0.25 mg/L) and has a clinical potential to treat respiratory infections [12,35,49,68].…”