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J A Waitz

Publications and source records attributed to J A Waitz.

At least 37 records · Page 2Linked to original sources
PubMed1978

Semisynthetic aminoglycoside antibacterials. 6. Synthesis of sisomicin, Antibiotic G-52, and novel 6'-substituted analogues of sisomicin from aminoglycoside 66-40C.

The discovery of aminoglycoside 66-40C, a novel dimeric, unsaturated imine produced by Micromonospora inyoensis, afforded a versatile intermediate for the synthesis of a variety of sisomicin analogues modified at the 6' position. The conversion of 66-40C into sisomicin, antibiotic G-52, and a series of novel 6'-substituted analogues of sisomicin is described, and the biological activity of the products is discussed.

Aminoglycosides↗
PubMed1978

Chemotherapeutic evaluation of 5-episisomicin (Sch 22591), a new semisynthetic aminoglycoside.

5-episisomicin (Sch 22591) is a novel semisynthetic aminoglycoside with a spectrum and potency similar to gentamicin in its activity against susceptible bacterial strains, but with increased potency against Pseudomonas, Providencia, and Proteus rettgeri. It is also more active than tobramycin and amikacin against these last-mentioned species.Against resistant strains, Sch 22591 is significantly more active than gentamicin or tobramycin. Against resistant gram-negative bacteria other than Pseudomonas, Sch 22591 has activity similar to that of amikacin, but Sch 22591 is more potent. Against Pseudomonas strains, it is active against most gentamicin- and tobramycin-resistant strains and is more active than the other three antibiotics. Some Pseudomonas strains are resistant to Sch 22591, but susceptible to amikacin. Against a selection of aminoglycoside-resistant staphylococci, Sch 22591 has very good activity against strains resistant to tobramycin, amikacin, and gentamicin. The superior in vitro potency of Sch 22591 against Pseudomonas has been confirmed in vivo in experimental infections in mice. Absorption in dogs is similar to that of other aminoglycoside antibiotics. The acute toxicity of Sch 22591 in mice is greater than that of gentamicin; its vestibular toxicity potential and nephrotoxicity potential in cats and rats appear to be similar to those of gentamicin.

Animals↗
PubMed1978

Method for qualitative determination of 2-deoxystreptamine.

We have developed a qualitative method to assay for the presence of 2-deoxystreptamine in hydrolysates of crude aminoglycoside preparations using a 2-deoxystreptamine-requiring idiotrophic mutant. The assay involves (i) incubation of a 2-deoxystreptamine-requiring mutant with 1 mg of a hydrolyzed preparation from a crude unknown antibiotic mixture per ml, and (ii) examination of the resultant incubation mixture for production of antibiotic(s) by disk assay.

Anti-Bacterial Agents↗
PubMed1978

Antibiotic biosynthesis by cofermentation of blocked mutants of two Micromonospora species.

Two aminocyclitol-negative Micromonospora mutants representing two different species, M. purpurea and M. inyoensis, and blocked at different steps in the biosynthetic pathway were paired and cofermented for the synthesis of antibiotics. The two blocked mutants were incapable of producing antibiotics alone except when 2-deoxystreptamine was added. When combined they produced gentamicins A, X(2), C(1a), and C(2b), which all have an amino group at the 2' position, and gentamicin B, which has a hydroxyl group at this position instead.

Anti-Bacterial Agents↗
PubMed1978

Biological activity of SCH 21420, the 1-N-S-alpha-hydroxy-beta-aminopropionyl derivative of gentamicin B.

Sch 21420, the 1-N-HAPA derivative of gentamicin B, has been compared to gentamicin, tobramycin and amikacin in a variety of in vitro and in vivo tests. Based on studies with a large number of sensitive and resistant bacteria, it was shown that Sch 21420 has a spectrum and potency essentially the same as that of amikacin. Serum levels in mice, rats, and dogs are similar to those of other aminoglycosides. Sch 21420 was found to be markedly less toxic than amikacin in chronic renal function tests in rats and thus appears to have an advantageously improved therapeutic index compared to amikacin.

Animals↗
PubMed1977

Renal pharmacology of netilmicin.

Netilmicin (Sch 20569), a new semisynthetic aminoglycoside, was studied for its effects on kidney function and mechanisms by which it is handled by the kidneys. Measurements of glomerular filtration rate (GFR) and urinalysis in chronic rat studies indicated that the nephrotoxicity of netilmicin was remarkably less than that of gentamicin. Gentamicin caused a dose-related reduction in GFR in association with glucosuria and elevated fractional excretion of K(+). By contrast, high doses of netilmicin produced only slight reduction in GFR with increased fractional excretion of K(+) but without glucosuria. In separate experiments, rats were shown to excrete 71 to 90% of netilmicin or gentamicin in 24 h after daily intramuscular administration of doses of 20 or 40 mg/kg for 4 days. In acute experiments on anesthetized dogs, GFR and renal plasma flow were unaffected at serum levels of 11.0 +/- 0.6 mug/ml maintained by constant infusion of netilmicin for 5 h. The renal clearance of netilmicin was significantly correlated with GFR. The urinary output of netilmicin was 80.0 +/- 4.2% of the infusion rate and was independent of urine flow over the range of 0.04 to 0.33 ml/kg per min. Preferential accumulation of netilmicin occurred in the renal cortex; the cortex-serum and medulla-serum ratios were 9.9 +/- 1.2 and 4.2 +/- 0.6, respectively. In addition, the extraction ratio of netilmicin, which was lower than that of inulin, suggested that netilmicin reabsorption occurs in the proximal tubule and results in cortical accumulation. It is concluded that netilmicin, like gentamicin, is excreted by the dog kidney by glomerular filtration plus limited reabsorption. However, the new drug is characterized by low intrinsic nephrotoxicity in rats.

Animals↗
PubMed1976

Biological activity of netilmicin, a broad-spectrum semisynthetic aminoglycoside antibiotic.

Netilmicin (Sch 20569) is a new broad-spectrum semisynthetic aminoglycoside derived from sisomicin. Netilmicin was compared to gentamicin, tobramycin, and amikacin in a variety of in vitro test systems as well as in mouse protection tests. Netilmicin was found to be similar in activity to gentamicin against aminoglycoside-susceptible strains in both in vitro and in vivo tests. Netilmicin was also active against many aminoglycoside-resistant strains of gram-negative bacteria, particularly those known to possess adenylating enzymes (ANT 2') or those with a similar resistance pattern. Netilmicin was found to be markedly less toxic than gentamicin in chronic studies in cats, although gentamicin appeared less toxic in acute toxicity tests in mice. The concentrations of netilmicin and gentamicin in serum were compared in dogs after intramuscular dosing, and the pharmacokinetics including peak concentrations in serum were found to be similar.

Amikacin↗
PubMed1976

A new broad spectrum aminoglycoside antibiotic, G-52, produced by Micromonospora zionensis.

G-52 is a new broad spectrum aminoglycoside produced by a species of the genus Micromonospora, Micromonospora zionensis. It has been differentiated from other known related antibiotics by a variety of chemical and biological methods. Its in vitro and in vivo spectrum of activity appears to be quite similar to that of verdamicin and gentamicin but is differentiated from them by its increased activity against 6'-N-acetylating strains.

Animals↗
PubMed1975

Verdamicin, a new broad spectrum aminoglycoside antibiotic.

Verdamicin is a new aminoglycoside antibiotic isolated from fermentation broths of a species of the genus Micromonospora, M. grisea. It has been differentiated from other known related antibiotics by a variety of chemical and biological methods. Its in vitro and in vivo spectrum of activity appears to be similar to those of gentamicin and sisomicin.

Aminoglycosides↗
PubMed1975

New polyene antifungal antibiotic produced by a species of Actinoplanes.

A new species of Actinoplanes, which has been deposited with the designation NRRL 5325 at the Northern Utilization Research and Development Division of the U. S. Department of Agriculture, produces a polyene antifungal complex designated as Sch 16656. The complex, consisting of one major and three minor components, is isolated from the fermentation broth by a solvent extraction procedure and purified by precipitation methods. The major component is a heptaene and is highly active in vitro and in vivo against Candida albicans. It is active also against strains of Torulopsis and is significantly more potent orally than candicidin in mice against Candida infections.

Actinomycetales↗
PubMed1975

Antibiotic G418, a new micrommomospora-produced aminglycoside with activity apainst protozoa and helminths: antiparasitic activity.

Antibiotic G-418 was shown to be superior to paromomycin and metronidazole in cecal amoebiasis. Of particular interest was the high degree of activity seen with a relatively short treatment at low levels. Although the antibiotic was trichomonacidal in vitro at low levels, in vivo results indicated that at levels tested the antibiotic did not always affect cures. The antibiotic appears to have promise as an anticestode agent, being more active than paromomycin against Hymenolepis nana and active as a single oral dose at low levels against Taenia spp.

Aminoglycosides↗
PubMed1974

Biological activity of antibiotic G-418, a new micromonospora-produced aminoglycoside with activity against protozoa and helminths.

On the basis of parallel in vitro studies with antibiotic G-418, gentamicin, neomycin, and kanamycin, antibiotic G-418 was found to be less potent than gentamicin but more active than either kanamycin or neomycin against most strains, with the exception of Pseudomonas, for which neomycin was more active than antibiotic G-418, and enterococci, for which antibiotic G-418 was more active than the other three antibiotics. Mouse protection tests indicated that antibiotic G-418 is approximately half as potent as gentamicin and its acute toxicity is one-half to one-third that of gentamicin.

Animals↗
PubMed1973

Interrelationships between disk and tube dilution sensitivity tests for the aminoglycoside antibiotics gentamicin, kanamycin, sisomicin, and tobramycin.

Poor statistical correlation was obtained between tube dilution test results and disk test results by using standard procedures. Significant regressions were obtained although they were not linear. Different regressions were obtained with different bacterial species. It is suggested that for the aminoglycosides studied (gentamicin, kanamycin, tobramycin, and sisomicin) both disk and dilution tests are useful in separating resistant from sensitive organisms. However, poor relationships were obtained between the two test types among sensitive organisms.

Aminoglycosides↗
PubMed1972

Comparative activity of sisomicin, gentamicin, kanamycin, and tobramycin.

Gentamicin, sisomicin, tobramycin, and kanamycin were compared in parallel tests in vitro and in vivo against a variety of bacterial strains and species. A number of differences were seen in vitro, in particular: (i) the lower activity of kanamycin, (ii) the greater activity of tobramycin against Pseudomonas, (iii) the greater activity of gentamicin and sisomicin against Serratia, and (iv) the generally similar results with tobramycin, gentamicin, and sisomicin against species other than Pseudomonas and Serratia, with the ranking in order of decreasing activity being sisomicin, gentamicin, and tobramycin. Analysis of disc test results suggested that the gentamicin disc is not adequate for testing the susceptibility of all bacteria to sisomicin or tobramycin. In vivo tests did not confirm all specifics of in vitro tests; results of in vivo tests indicated that sisomicin may be the most active. It is suggested that the place of each of the antibiotics in human therapy can best be evaluated by more rigorous in vivo tests and clinical studies rather than extensive in vitro comparisons.

Aminoglycosides↗