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Paper chromatography is very helpful in the identification and comparison of antibiotics, but very few results from the application of this technique have been published so far. The awakening of interest in the search for antibiotics which are active against fungi pathogenic to plants and animals makes the investigator aware of the scant information that is available to help characterize such agents. A knowledge of the Rf values of the known antifungal agents would help advance the search for such therapeutic materials. Often these values, in conjunction with the biological inhibitory activities, are the only criteria by which one can determine whether the unknown agent appears to be a new material. When the Rf data are obtained for shake cultures, one can eliminate many previously described antibiotic-producing organisms from further study, thus allowing more research to be applied to antibiotics which are new and different. The studies reported in this paper should serve as a guide to the identification of some of the known antifungal antibiotics.

SummaryA procedure has been developed whereby paper chromatograms of antiviral agents can be developed by applying them to virus infected, agar overlay, chick embryo cell tissue cultures. Plaque-free zones are produced, thus indicating the area on paper chromatogram where the active material can be located. Using antiviral substances antibiotic W-112 and isatin-monothiosemicarbazone, W. Nile and vaccinia viruses, and 4 chromato-graphic solvent systems, it was possible to localize the biological activity of these antiviral agents. As little as 1 μg of antibiotic W-112 produced large plaque-free zones when paper chromatogram was applied to the overlay culture 1 hr after virus infection. When 100 μg of same material was used, large plaque-free areas resulted even when the paper was applied 46 hr after virus infection. Isatin-monothiosemicarbazone at 50 μg level not only produced a plaque-free zone but also produced a yellow spot on paper chromatogram that coincided exactly with the zone of antiviral activity.

The test paper here described makes it relatively easy to choose the antibiotic best suited for treatment of a given bacterial infection. Each type of test paper bears both a culture medium and an antibiotic and is supplied, dry and sterile, in a transparent envelope. For a given test, the paper is wetted and inoculated and the envelope with its contents is incubated. It is not necessary to wait for the appearance of visible colonies because the metabolic activity of the bacteria is detected by an indicator (triphenyltetrazolium chloride) which is colorless until reduced to a bright red dye by bacterial enzymes. The reliability of the new test was established by a comparative study with other methods in 100 clinical cases. The test paper is easily stored, and the entire unit can be incinerated after use. It is therefore useful in general office practice and should help to make sure that each patient receives the most effective antibiotic.

Microbiological assay of individual antibiotics in mixtures of antibiotics depends on the use of selective inactivation and/or of test bacteria with differential susceptibility. Controlled experiments revealed that streptomycin in concentrations of 20 and 40 μg/ml did not influence a disk diffusion assay of penicillin with Sarcina lutea (ATCC 9341) as the test organism. In the case of penicillin concentrations less than or equal to 1 IU/ml, addition of 80 μg of streptomycin per ml influenced the penicillin assay significantly. Clinical use of streptomycin resulting in levels above 40 μg/ml usually did not occur; therefore penicillin could be assayed as though streptomycin were not present. We observed additionally that S. lutea was unable to grow on agar plates prepared with semicarbazide hydrochloride.

Addition of aromatic acids to the culture medium of Streptomyces caelestis results in the production of antibiotics different from the celestosaminides normally produced by the organism. The new antibiotic produced when 4-aminosalicylic acid was added to the culture medium was isolated and characterized as desalicetin 2'-(4-aminosalicylate). Although biological evaluation of this antibiotic is not complete, its in vitro antibacterial spectrum is identical to that of celesticetin.

Flavomycoin is a polyene antibiotic isolated from the mycelium of Streptomyces roseoflavus ARAI 1951 var. jenensis nov. var. JA 5068 as yellow-green crystals. It shows inhibitive activities against yeasts and fungi as well as protozoa. It is optically active, exhibits an ultraviolet spectrum without fine structure with maxima at 363 nm and 263 nm. Analytical studies indicated that the molecular formula of the antibiotic is C41H68O10 and the molecular weight 721. These results were confirmed by degradation to the parent hydrocarbon and by catalytic hydrogenation. As flavomycoin is different from the related substances mycoticin and flavofungin, it must be considered as a new antibiotic.

Scopafungin (U-29,479) is a crystalline, nonpolyenic antimicrobial agent obtained from the culture broth of Streptomyces hygroscopicus var. enhygrus var. nova UC-2397. Scopafungin inhibits, in vitro, a variety of pathogenic fungi, yeasts, and gram-positive bacteria.

SummaryA procedure has been developed whereby agar diffusion technics used in bacteriology can be applied to antiviral agents. Chick embryo cell monolayers were grown in Pyrex baking dishes, infected with virus and overlaid with agar. Filter paper discs impregnated with the test materials were deposited on the hardened agar surface. After proper incubation the virus produced plaques in the cell sheet, except in the area around a disc containing an antiviral agent. Since size of the plaque-free zone was proportioned to concentration of the antiviral agent present in the disc, bioassays were simply performed in exactly the same manner as done with antibacterial antibiotics.

Lomofungin is a new antimicrobial agent obtained from the culture broth of Streptomyces lomondensis sp. n. UC-5022. Lomofungin is an acidic, olive-yellow, crystalline compound which inhibits, in vitro, a variety of pathogenic fungi, yeasts, and gram-positive and gram-negative bacteria.

A new antibiotic, cryomycin, was isolated from the culture filtrate of a facultatively psychrophilic streptomycete. As a result of taxonomic studies, it was considered a new subspecies for which the name Streptomyces griseus subsp. psychrophilus, YOSHIDA, TANI and OGATA, is proposed. The type strain is AKU 2881. This organism grows at 0-37°C and produces cryomycin at 0-18°C. Cryomycin is a peptide antibiotic containing a rather large amount of glycine in its molecule. It darkens at 214-217°C with decomposition. This antibiotic is highly active against Gram-positive bacteria in vitro. The LD50 in mice by intravenous injection is 150 mg/kg.

Kitasatoa kauaiensis, a new species of the genus Kitasatoa, belonging to the family Streptoplanaceae, produces 3 kinds of antibiotics in a culture broth. These antibiotics were identified as chloramphenicol, bottromycin and fradicin based on their physico-chemical and biological properties. A new differential bioassay method for chloramphenicol and bottromycin produced in the same culture broth was established.

Two new compounds, pyracrimycins A and B, have been isolated from a Streptomyces species named Streptomyces eridani Coronelli et al. n. sp. The morphological and physiological characteristics of this strain are described in the present paper together with the production and properties of the two metabolites. Pyracrimycin B is biologically inactive whereas pyracrimycin A is active in vitro against both Gram-positive and Gram-negative bacteria.

A graphic method of predicting antibiotic yields in continuous flow reactors is presented and discussed using the novobiocin fermentation as a model process. Extension to other antibiotic fermentations and steroid bioconversions is emphasized. In the case of the novobiocin fermentation it was concluded that a combination of one growth stage and one or two antibiotic production stages would be the most economic reactor system to conduct such a fermentation on a continuous basis.

The inhibitory action of an antibiotic isolated fromB. subtilis is studied onC. albicans, C. clausenii, C. langeronii, C. stellatoidea, andC. visvanathii, as a possible means forC. albicans rapid identification. Growth inhibition ofC. albicans by the antibiotic was observed when the yeast was preincubated on malt-agar slants, at 30° C, during 24 hours, and tested afterwards for antibiosis on Sabouraud-agar plates. No growth inhibition could be detected withC. clausenii, C. langeronii, C. stellatoidea, andC. viswanathii, under the same experimental conditions.

Sclerothricin is a new strongly basic antibiotic obtained from the culture filtrate of Streptomyces sclerogranulatus SHIMAZU et YONEHARA nov. sp. The antibiotic is active against gram-positive and gram-negative bacteria and some fungi. Sclerothricin (C16H30O8N6) seems to belong to the streptothricin group. It has two N-methyl, a free carboxyl and two N-terminal groups. No carbamoyl group is present.

Isolation, purification and physicochemical properties of the antibiotic complex YA-56, a family of phleomycin-bleomycin group, are described. The antibiotic YA-56 complex was found to be composed mainly of two active components named YA-56 X and Y. These components were clearly differentiated from the reported phleomycins and bleomycins by their physicochemical properties. However, by direct comparison, YA-56 X was found to be identical with zorbamycin reported recently. YA-56 Y was recognized to be a new antibiotic.

The fate of the orally effective antibiotic D-cephaloglycin and its much less active L-enantiomer has been studied in the rat. D-Cephaloglycin-14C is metabolized by two pathways, (1) hydrolysis of the amide linkage to form D-2-phenylglycine-14C and (2) deacetylation to form deacetyl-D-cephaloglycin-14C. D-Cephaloglycin is absorbed from the gastro-intestinal tract at least in part as the intact antibiotic, L-Cephaloglycin-14C is rapidly metabolized to L-2-phenylglycine-14C and its metabolites. In contrast to the results with D-cephaloglycin-14C, no intact L-cephaloglycin-14C or deacetyl-L-cephaloglycin was excreted in the urine of rats.

Dianemycin is an antibiotic previously reported to affect cation transport and to be effective in treating coccidiosis in chickens. It is isolated from a fermentation broth of Streptomyces hygroscopicus. The compound was found to be primarily active against gram-positive organisms. The chemical properties of dianemycin indicate a close relationship to monensin and other acidic cation complexing compounds.

We have isolated a temperature-sensitive mutant of S. cerevisiae which has proven useful for the isolation of antibiotic-sensitive strains.

A new antibiotic, gluconimycin, was isolated from Streptomyces AS 9. The systematic position of the organism is discussed. Gluconimycin has a polypeptide nature. It contains iron and gluconic acid in its molecule. Thus it has been classified as a member of sideromycins. Gluconimycin is considered from the fast moving type when chromatographed by butanolacetic acid-water. The antibiotic is active against Gram+ve, Gram-ve bacteria and some fungi. The antibiotic exerts high toxicity when injected in mice.

Of a total of 739 actinomycetes freshly isolated from soil samples from China, 515 (69·7%) were antibiotically active. Their antibiotic spectrum was determined against 14 test micro-organisms, including bacteria, yeasts and fungi, and 386 of them were characterized by paper chromatography using agar blocks, by behaviour on agar plates incorporating ion-exchange resins and by u.v. absorption spectrum (to detect polyene substances). Of these strains, 195 (50·5%) produced a mixture of antibiotics of both polyene and non-polyene type. On the basis of these results the active strains have been classified in various ways.

Antibiotic-resistant enterobacteria, the vast majority of which carried transmissible R factors, were isolated from 81 out of a total of 100 healthy infants. There was surprisingly little correlation between previous antibacterial therapy and the resistant enterobacterial flora.

Out of 200 infections due to Bacteroides fragilis occurring over a period of three years 133 were related to the intestinal tract, 55 to the genitourinary tract, and the remainder were in bedsores and ulcers; 56% occurred in patients undergoing major intestinal surgery.B. fragilis was isolated in pure culture from 56% of the infections. In mixed culture it was most commonly associated with Klebsiella and Enterobacter species. Other anaerobic bacteria were isolated in 9% of the mixed cultures.Altogether 131 (65.5%) of the patients recovered without antibiotic therapy or further surgery, but 59 (29.5%) developed complications and 10 (5%) died. The commonest complication was abscess formation, and the incidence was highest with infections associated with malignancy (44%) and lowest with obstetric infections (5%). The mortality was 5% overall but in the presence of bacteraemia it rose to 33%.Only 43 patients received appropriate chemotherapy. Clindamycin was the most effective antibiotic, having a recovery rate of 78%, but this rate was little better than in untreated patients (65%). The role of prophylactic antibiotic therapy in preventing bacteroides infection remains to be studied.The incidence of the isolation of bacteroides from wound infections after major intestinal surgery rose from 13% in 1970 to 81% in 1973. This increase was due to both the accurate collection and care of specimens while in transit to the laboratory and the use of selective media for the isolation of bacteroides in laboratory culture. The importance of these precautions is emphasized.

Purpuromycin (C26H18O13) is a new antibiotic isolated from the culture broth of Actinoplanes ianthinogenes proposed as a new species on the basis of its morphological, cultural and physiological characteristics. The antibiotic, obtained as purple crystals, belongs to the naphthoquinone group of antibiotics and resulted to be related to rubromycins. The isolation and purification procedures and the chemico-physical properties of the product are reported. Purpuromycin is active in vitro against Gram-positive bacteria at 0.005-0.02μg/ml, at 1-20μg/ml on Gram-negative bacteria and at 0.2-0.5 μg/ml on fungi.

A strain of Myxococcus xanthus, referred to as M. xanthus TA, has been isolated which produces an antibiotic capable of inhibiting growth of certain Gram-positive and Gram-negative bacteria. Antibiotic production was significantly inhibited when the concentration of protein hydrolysate in the production medium exceeded 1%. The antibiotic was purified over 1000 times to apparent homogeneity by silicic acid chromatography and by a variety of preparative alumina thin-layer chromatographic procedures. The purified antibiotic was partially characterized by its chromatographic behavior in six solvent systems, stability to acid, alkali and heat, infrared, ultraviolet, and mass spectra. The antibiotic has a λmax of 242 nm in methanol.

Tobramycin and amikacin are new aminoglycoside antibiotics which resemble gentamicin and kanamycin respectively in pharmacokinetic, toxicological, and some microbiological respects. Minimum inhibitory concentrations for these four antibiotics have been determined against 393 bacterial strains (13 species from eight genera) isolated from clinical materialKanamycin was the least active, 89% of the Pseudomonas aeruginosa strains being resistant. Resistance was also found in 21% of the Klebsiella aerogenes, 16% of the indoleproducing Proteus species, 4% of the E. coli and 3% of the Enterobacter spp. tested. Providenca stuartii strains were often resistant to gentamicin and tobramycin.Apart from these exceptions, however, all the organisms tested were sensitive to all four compounds, gentamicin and tobramycin usually showing the highest intrinsic activity.Amikacin was the most active compound against a selection of strains chosen because of their resistance to one or more of the aminoglycosides. Thus, amikacin represents a significant advance over kanamycin and seems to be superior to gentamicin in terms of its in-vitro properties. This is especially the case in those unusual circumstances when gentamicin-resistant strains are a problem. We suggest that amikacin warrants further investigation since it may prove to be a valuable alternative to gentamicin in the treatment of life-threatening infections.

A new amino acid antibiotic, amiclenomycin is produced by Streptomyces lavendulae subsp. amiclenomycini OKAMI. The chemical structure of amiclenomycin is L-2-amino-4-(4'-amino-2', 5'-cyclohexadienyl)-butyric acid. The antibiotic inhibits growth of mycobacteria and this activity is reversed by biotin and desthiobiotin. α-Methyl-desthiobiotin is coproduced along with amiclenomycin.

tetaine, a low molecular weight broad spectrum antibiotic of aminoacid derivative type and of low toxicity, is an inhibitor of cell wall synthesis in Escherichia coli K-12 3000 HFr strain. Tetaine inhibits the incorporation of 3H DAP and 3H L-Ala to murein of E. coli. In the presence of tetaine nucleotide precursors of murein synthesis were radioactive mainly due to the 3H uridine and not 14C alanine, what indicates the lack of incorporation of alanine to UDP-Mur-NAc. It is postulated that tetaine inhibits the synthesis of murein nucleotide precursors at the level of incorporation of first alanine moiety.

R factors conferring a high level of resistance to trimethoprim have been identified in one strain of Escherichia coli and one of Klebsiella aerogenes, both isolated from infected urines.

The sideromycin antibiotic A 22,765 is taken up from the medium by Staphylococcus aureus SG 511 against a concentration gradient. In contrast to this, A 22,765-resistant cells display an extremely low degree of permeability to the molecule. Ferrioxamine B penetrates the cells in only very minute quantities, but nevertheless antagonises permeation by A 22,765. This permeation-antagonising effect of ferrioxamine B is discussed.

Kalafungin is a new antimicrobial agent obtained from the culture broth of a soil isolate of Streptomyces tanashiensis , designated Streptomyces tanashiensis strain Kala UC-5063. Kalafungin is a chemically stable, nonpolyene agent which is ex-extremely inhibitory in vitro against a variety of pathogenic fungi, yeasts, protozoa, gram-positive bacteria, and, to a lesser extent, gram-negative bacteria.

Melinacidin is a crystalline mixture of closely related antibacterial agents produced by Acrostalagmus cinnabarinus var. melinacidinus. Melinacidin inhibits a variety of Gram-positive bacteria in vitro but is found to be toxic and ineffective in the treatment of experimental bacterial infections in mice. Melinacidin which inhibits the growth of KB and L-1210 cells in tissue culture appears to belong to the "3, 6-epidithiadiketopiperazine" group of antibiotics.

An actively antibiotic producing actinomycete, Streptomyces NRC-101, was isolated from Egyptian soil. The strong antibiotic effect of the fermentation broth of the microorganism on grampositive and gramnegative bacteria led to experiments for the isolation of the active principle. After isolation and purification its physico-chemical and biological properties were different from the well-known antibiotics. Therefore, it was identified as a new antibiotic designated as antibiotic NRC-101.

Three new antibiotics, neoantimycin, neaureothin and ochramycin have been isolated from Streptoverticillium orinoci. The systematic position of the organism is discussed. Neoantimycin is related to the antimycin antibiotics group; neoaureothin shows some similarity with aureothin. Ochramycin is an amphoteric compound containing in its molecule an octaene chromophore. The first two antibiotics show a slight antifungal activity only. Ochramycin is active against gram +ve, but not against gram -ve bacteria; its activity against yeasts and fungi is very slight. Toxicity data are reported; no therapeutical effectiveness has been observed in experimental infections in mice.

A new antibiotic O-2867 inhibiting the growth of Piricularia oryzae, a plant pathogenic fungus of rice, was isolated from a Streptomyces sp. Antibiotic O-2867 is water-soluble, amphoteric and consists of 2 components, O- 2867-α and β. O-2867-α was obtained as an amorphous powder and O-2867-β as colorless needles. Both antibiotics are active against P. oryzae in vitro but are not effective in pot tests using rice plants infected with P. oryzae.

PRISTINAMYCIN is a new antibiotic obtained from Streptomyces pristinae spiralis, a Streptomyces isolated from a soil sample taken at San Carlos (Cordoba) in Argentina1. It is made up of several components and belongs to the family of synergistic antibiotics which includes streptogramin, staphylomycin and ostreogrycin. Chromatographic analysis has shown that pristinamycin is a mixture of two groups of components, the proportions of which vary within certain fixed limits

During an antibiotic screening programme, a new biologically active complex was isolated from an unidentified Streptomyces, strain Ac6 5691), which was obtained from a garden soil in Calcutta, India. This antibiotic complex was found to contain two water-soluble active fractions of which the major one was designated as boseimycin. This commuication describes the isolation, purification and characterization of boseimycin. It was found to have a close relationship to the streptothricin group of antibiotics but was differentiated from them on the basis of its physico-chemical and microbiological properties.

1. The urinary excretion of total sulphanilamide (free and acetylated) in rats receiving Prontosil or Neoprontosil orally is considerably reduced when the rats are treated with antibiotics to suppress their intestinal flora. The absorption and metabolism of sulphanilamide are unaffected by such treatment with antibiotics.2. The lipid-soluble Prontosil after oral or intraperitoneal administration is partly excreted in the bile as a polar conjugate, apparently an N-glucuronide, and this drug appears to be converted into sulphanilamide partly by metabolism by the body tissues and partly by enterofloral metabolism.3. The polar, water-soluble Neoprontosil is poorly absorbed from the intestine and when given orally is largely reduced to sulphanilamide by the gut flora before absorption. When given intraperitoneally, a large proportion (up to 70%) of the drug is excreted in the bile unchanged, and it would appear that only a small proportion of the drug (ca. 20%) is converted to sulphanilamide in the tissues, th...

A rise in Salmonella typhimurium infection was observed in calves in Britain during 1964–6, follwing the adoption of the intensive farming method. A single phage type of S. typhimurium, type 29, was incriminated as the major pathogen. Attempts to treat and control the disease with a range of antibiotics were ineffective, but resulted in the acquisition of transferable multiple drug resistance by type 29. The transmission of drug-resistant type 29, directly or indirectly, from bovines to man resulted in many human infections. Transferable drug resistance reaching man from enterobacteria of animal origin may ultimately enter specifically human pathogens. Infections such as that caused by type 29 can be eliminated, not by the massive use of antibiotics but by improvement in conditions of animal husbandry and reduction in the opportunities for the initiation and spread of the disease. A reappraisal is needed of the methods of using antibiotics to determine how these methods can be improved, in order to conserve the long-term efficacy of the antibiotics.