Accordingly, and in contrast to colistin and polymyxin B, the NAB compounds are excreted into urine to a significant extent.
Poster F1-3966: "Novel Polymyxin Derivatives are Effective in Treating Peritoneal E.
Colistin and polymyxin B resistances were defined as MIC [greater than or equal to] 4 mg/L (4).
2% were resistant to polymyxin B and colistin, respectively.
Of the PDR isolates, 8 were resistant even to colistin and polymyxin B.
Because of the lack of a standard definition for multi-drug resistance in the literature, we defined multidrug resistance as resistance to all or all but 1 antimicrobial drug class commonly prescribed for treatment of patients with gram-negative infections, with the exclusion of polymyxins
isolates with reduced susceptibility to polymyxins.
The susceptibility to polymyxin B and meropenem were tested by disk diffusion and agar dilution techniques according to NCCLS recommendations (9,10).
Among the five polymyxin B-resistant Acinetobacter spp.
essential oils (EO): MyHN, MyK and MyB, and eight antibiotics (AB): ceftriaxone, gentamicin, ciprofloxacin (CIP), kanamycine, amikacin, tetracycline, chloramphenicol, and polymyxin B (PMB) (Sigma, USA).
The most efficient antibiotic was polymyxin B, while the chloramphenicol and ceftriaxone had the lowest effect, showing no activity against any strain.
For instance, a synergy was demonstrated when ampicillin-sulbactam was combined with a carbapenem, or between meropenem and polymyxin B (Ozseven et al.