Gentamicin antibacterial activity

The in vivo protective activity of rifaximin was studied in mice, infected experimentally by intraperitoneal inoculation of S. aureus Colliva and compared to that of rifampicin (a systemic rifamycin) and gentamicin (a poorly absorbed aminoglycoside) [74]. After oral administration, only rifampicin was effective whereas the other two compounds were inactive at doses up to 10 mg/kg. However, when injected subcutaneously, rifaximin displayed a good therapeutic efficacy (table 2). While confirming its antibacterial activity, these results clearly indicate that rifaximin, like gentamycin, is poorly absorbed after oral administration. 

It belongs to family nebramycins, is isolated from Streptomyces tenebrarius. Its antibacterial activity is similar to gentamicin and slightly more active than gentamicin against Pseudomonas aeruginosa and Proteus. 

The aminocyclitol antibiotics—gentamicins, kanamycins, neomycins, paramomycins, spectinomycins, streptomycins, and tobramy-cins—constitute a group of basic oligosaccharides that have a broad, antibacterial activity.1,46... 

Tobramydtt. The antibacterial activity and pharmacokinetic properties of tobramycin resemble those of gentamicin, and the therapeutic uses of tobramycin are essentially identical to those for gentamicin. Although some bacteria are resistant to both gentamicin and tobramycin, it is impredictable in individual strains. Amikacin is usually effective for infections caused by organisms resistant to both gentamicin and tobramycin. 

Neomycin is a topical aminoglycoside widely nsed for skin wounds and in otolaryngology. Its antibacterial activity resembles that of gentamicin and tobramycin, except that P aeruginosa, S. pneumoniae, and the a-hemolytic streptococci are generally resistant. Neomycin s usefnl-ness for treating acnte bacterial conjunctivitis is limited... 

Fig. 23 The combination of sophoraflavanone G (10), ampicillin (113), and gentamicin (114) from the roots of Sophora flavescens for antibacterial activity...

Aminoglycoside antibiotics (257), including kanamycin A, tobramycin, and gentamicin C complex, have been acylated with 1 mole of disodium carbenicillin (258) to give monoacylated derivatives (e.g., 259) (compounds 257-259). The resulting compounds were devoid of antibacterial activity against several strains tested, however, and showed no toxicity [135]. 

The deoxystreptamine aminoglycoside antibiotics catenulin (paromomycin), neomycin, kanamycin, and gentamicin qualitatively share ototoxicity, nephrotoxicity, and antibacterial activity the first named however is used only for intestinal infections (amoebic and bacterial), the second is used primarily for local and intestinal infections while kanamycin which combines lower nephro- and ototoxicity with good activity... 

Netilmicin, an aminoglycoside, is similar to gentamicin and tobramycin in its pharmacokinetic properties. It has broad antibacterial activity against aerobic Gram-negative bacilli and causes less ototoxicity and nephrotoxicity (see also Figure 88). 

Deamino- and 1-deamino-l-hydroxy- analogues in the gentamicin series have been obtained by isolation and synthesis (178—180). These derivatives have weak antibacterial activity, although the 1-epi analogues of gentamicin C, netilmicin, and sisomicin are highly active (180). 

Table 4 The antibacterial activity and lethal doses of peptoids and gentamicin against Mycobacteria and macrophages, respectively...

Certain aminoglycoside antibiotics, including gentamicin and streptomycin, have been observed to interact with the acidic mucopolysaccharide heparin, condroitin sulfate, and hylauronic acid with reduction of antibacterial activity. The interaction of aminoglycosides with the acidic mucopolysaccharides has been suggested to result in the accumulation of the drug in the kidney and in the inner ear and to partly account for the well-documented nephrotoxicity and ototoxicity of this group of antibiotics. 

Shows broad spectrum antibacterial activity against gentamicin resistant strains. Powder. Sol. H2O, MeOH fairly sol. EtOH, Me2CO poorly sol. EtOH, hexane. Mp 102-112°. [a]o +172 (c, 0.3 in H2O). Major component of complex. 

As Gentamicin B, G-226 with R = NH2, R = CH3, R = OH C2oH4oN40,o 496.557 Aminoglycoside antibiotic. Minor metab. from Micromorwspora purpurea and Micromonospora echinospora. Shows antibacterial activity similar to other Gentamicina Sol. H2O, MeOH fairly sol. EtOH poorly sol. butanol, hexane. 

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