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PubMed1990

[Antibacterial activity of various antibacterial agents against methicillin-resistant Staphylococcus aureus, and difference in antibacterial activity between aminoglycosides by coagulase type. Comparison of isolates obtained in the period from 1982 to 1986 and isolates in recent 6 months].

The sensitivity of methicillin-resistant Staphylococcus aureus (MRSA) isolated in our hospital during the period from November 1988 through April 1989 to various antibacterial agents was examined. Isolates were obtained from blood (4 isolates), sputum (40), bile (1), ascites (1) and urine (4). All isolated MRSA were resistant to cefazolin, cefmetazole, cefuzonam, flomoxef, and tobramycin. More than 80% of the isolates were resistant to fosfomycin and amikacin. 60% were resistant to ofloxacin (OFLX). 46% were sensitive to minocycline. 50% or more of the isolates were sensitive to gentamicin (GM), dibekacin (DKB) and astromicin (ASTM). 88% were sensitive to netilmicin. All the isolates were sensitive to vancomycin and arbekacin. The incidence of OFLX-resistant isolates was increased compared with the results of the previous study. Most of the isolates were coagulase type II. GM, ASTM and DKB were less active against type IV isolates, but they had sufficient antibacterial activity against the type II isolates.

Aminoglycosides↗

PubMed1999

Antibacterial use in community practice: assessing quantity, indications and appropriateness, and relationship to the development of antibacterial resistance.

Most use of antibacterials occurs in community practice; however, despite the widespread belief of inappropriate use and the resultant increase in antibacterial resistance, little data exist describing antibacterial use in this setting. A MEDLINE search of English-language articles was conducted for epidemiological studies assessing quantity, indication and appropriateness of antibacterial use in community practice. A 1983 study of international antibacterial use described considerable disparities in quantity of use between countries. Subsequent longitudinal studies from the US, Canada, Australia and the UK described changing patterns of antibacterial use. No increase in the total rate of antibacterial use was reported by any of the 4 countries; however, all countries reported increased use of newer and/or broad-spectrum agents (e.g. fluoroquinolones, amoxicillin-clavulanic acid, cephalosporins and new macrolides] coupled with decreased use of older and/or narrow-spectrum agents [e.g. phenoxymethylpenicillin (penicillin V), erythromycin, ampicillin and tetracycline). Most (approximately three-quarters) use of antibacterials was in the treatment of respiratory tract infections. Prescribing rates for respiratory tract infections of presumed viral aetiology (e.g. the common cold) ranged from 17 to 60% in the UK and US, respectively. Among indications for which antibacterials were indicated, the appropriateness of antibacterial use received little study. Correspondingly, the rates of antibacterial resistance among common respiratory pathogens (Streptococcus pneumoniae and Haemophilus influenzae) have increased significantly in the past decade, although disparities exist between countries. Antibacterial use is considered a major factor in the development of antibacterial resistance, although the relationship between community antibacterial use and resistance has been poorly described. Further study of antibacterial usage patterns and associated resistance patterns is fundamental to the development of methods to reduce unnecessary and inappropriate use, thereby slowing the development of antibacterial resistance in the community.

Anti-Bacterial Agents↗

PubMed2002

Effect of ambient conditions on the antibacterial activity of antibacterial agent based on sodium titanium phosphate.

OBJECTIVE: To investigate the effects of ambient conditions on the antibacterial activity of inorganic antibacterial agent based on sodium titanium phosphate. METHODS: The number of live E. Coli ATCC 44113 was counted after the suspension was shaken and incubated in flask with antibacterial agent under ambient conditions. RESULT: The number of live bacteria increased when the concentration of bacteria increased in the range of 1.2 x 10(2) to 1.2 x 10(8) cfu/ml. The antibacterial activity increased with the increase of ambient temperature in the range of 16 approximately 46 degrees C, showing good antibacterial activity at human body temperature. With the increase of the concentrations of co-existing NaCl and protein, the antibacterial activity was found to decrease at first and level off at 0.01 g/ml and 0.0005 g/ml respectively. CONCLUSION: The antibacterial agent has to be used together with organic antibacterial agent in order to achieve good antibacterial effect when the ambient bacterial concentration is high. The antibacterial agent is promising to be used in the preparation of antibacterial cloth because it is highly effective at body temperature and expected to remain antibacterial in perspiration.

Anti-Bacterial Agents↗

PubMed2003

Investigation of antibiotic and antibacterial agent cross-resistance in target bacteria from homes of antibacterial product users and nonusers.

AIM: To describe the relationship between antibiotic and antibacterial resistance in environmental and clinical bacteria from home environments across geographical locations, relative to the use or nonuse of antibacterial products, with a focus on target organisms recognized as potential human pathogens. METHODS AND RESULTS: In a randomized study, environmental and clinical samples were collected from the homes of antibacterial product users (n=30) and nonusers (n=30) for the isolation of target bacteria for antibiotic and antibacterial testing in three geographical areas (in USA and UK). Isolates were tested for antibiotic susceptibility, with selected antibiotic-resistant and antibiotic-susceptible isolates tested against four common antibacterial agents (triclosan, para-chloro-meta-xylenol, pine oil and quaternary ammonium compound). Prequalified users and nonusers at each location were randomly selected after meeting exclusionary criteria. Of 1238 isolates, more target bacteria were recovered from nonuser than user homes. Of Staphylococcus aureus isolates (n=33), none showed resistance to oxacillin or vancomycin; for Enterococcus sp. (n=149), none were resistant to ampicillin or vancomycin; and for Klebsiella pneumoniae (n=54)and Escherichia coli (n=24), none were resistant to third generation cephalosporins. Antibiotic resistance to one or more of the standard test panel drugs for Gram-positive and Gram-negative target bacteria was comparable between nonuser and user homes for both environmental and clinical isolates [e.g. resistance of environmental coagulase-negative (CN) Staphylococcus sp. was 73.8% (124/168) from nonuser homes and 73.0% (111/152) from user homes, and Enterobacteriaceae other than E. coli, 75.9% (186/245) from nonuser homes compared with 78.0% from user homes]. Of 524 Gram-negatives tested against preferred/alternative drugs, 97.1% (509/524) were susceptible to all antibiotics, across both groups. Isolates of S. aureus, Enterococcus sp. and CN Staphylococcus sp. susceptible to all preferred treatment drugs showed comparable antibacterial minimum inhibitory concentration (MIC) results between nonuser and user home isolates. For Gram-positives resistant to one or more preferred drugs, greatest resistance to antibacterial active ingredients was found in the nonuser group. For Gram-negatives, the antibacterial MIC data were comparable for isolates that were fully susceptible and resistant to one or more preferred/alternative treatment antibiotics. CONCLUSIONS: The results showed a lack of antibiotic and antibacterial agent cross-resistance in target bacteria from the homes of antibacterial product users and nonusers, as well as increased prevalence of potential pathogens in nonuser homes. SIGNIFICANCE AND IMPACT OF THE STUDY: It refutes widely publicized, yet unsupported, hypotheses that use of antibacterial products facilitates the development of antibiotic resistance in bacteria from the home environment.

Ampicillin↗

PubMed2000

Addition of antibacterial agents to MMA-TBB dentin bonding systems--influence on tensile bond strength and antibacterial effect.

To produce a bonding system which has both high bond strength and antibacterial properties, an antibacterial agent (vancomycin: VCM or metronidazol: MN) was added to the PMMA powder of 4-META/MMA-TBB resin (CB). The influence of the addition of an antibacterial agent on tensile bond strength to dentin and the antibacterial effect were investigated in this study. Forty-seven freshly extracted bovine first or second incisors were used to measure the tensile bond strength to dentin. The bond strengths to bovine dentin were not significantly decreased by addition of VCM (1%, 2%, 5%), or MN (1%) to CB (p < 0.05). The antibacterial effect of CB containing antibacterial agent on six strains of bacteria was investigated by the agar plate diffusion method, analyzing the appearance of the inhibition zone around a resin disk following anaerobic culturing. The resin disks containing VCM showed antibacterial effects on all of the strains examined; the widths of the inhibition zones were 4-15 mm. The resin disks containing MN showed antibacterial effects on three strains; the widths of the inhibition zones were 0-4 mm. It was thus possible to produce a bonding system with both antibacterial effect and high tensile bond strength by addition of VCM to PMMA powder.

Acrylic Resins↗

PubMed2001

Antibacterial prescribing and antibacterial resistance in English general practice: cross sectional study.

OBJECTIVE: To quantify the relation between community based antibacterial prescribing and antibacterial resistance in community acquired disease. DESIGN: Cross sectional study of antibacterial prescribing and antibacterial resistance of routine isolates within individual practices and primary care groups. SETTING: 405 general practices (38 groups) in south west and north west England. MAIN OUTCOME MEASURES: Correlation between antibacterial prescribing and resistance for urinary coliforms and Streptococcus pneumoniae. RESULTS: Antibacterial resistance in urinary coliform isolates is common but the correlation with prescribing rates was relatively low for individual practices (ampicillin and amoxicillin r(s)=0.20, P=0.001; trimethoprim r(s)=0.24, P=0.0001) and primary care groups (ampicillin and amoxicillin r(s)=0.44, P=0.05; trimethoprim r(s)=0.31, P=0.09). Regression coefficients were also low; a practice prescribing 20% less ampicillin and amoxicillin than average would have about 1% fewer resistant isolates (0.94/100; 95% confidence interval 0.02 to 1.85). Resistance of S pneumoniae to both penicillin and erythromycin remains uncommon, and no clear relation with prescribing was found. CONCLUSIONS: Routine microbiological isolates should not be used for surveillance of antibacterial resistance in the community or for monitoring the outcome of any change in antibacterial prescribing by general practitioners. Trying to reduce the overall level of antibiotic prescribing in UK general practice may not be the most effective strategy for reducing resistance in the community.

Anti-Bacterial Agents↗

PubMed1994

Synthesis and antibacterial activity of thiazolopyrazine-incorporated tetracyclic quinolone antibacterial agents. 2.

A novel series of 8-(2-substituted morpholino)-9,1-[(N-methylimino) methano]-7-fluoro-5-oxo-5H-thiazolo[3,2-a]quinoline-4-carboxylic acids, designated 8a-j, with a unique tetracyclic structure were synthesized, and the in vitro and in vivo antibacterial activities against Gram-positive strains, including methicillin-resistant Staphylococcus aureus isolates (MRSA), and Gram-negative strains were evaluated. These morpholino derivatives, 8a-j, showed excellent in vitro antibacterial activities against Gram-positive bacteria. The substitutions at the C-2 position of the 8-morpholino moiety of compound 8 play an important role in the enhancement of in vivo antibacterial activity. The unsubstituted morpholino derivative 8a, the 2,6-dimethyl derivative 8c, and the 2-ethylmorpholino derivative 8d showed poor in vivo antibacterial activity, while 8b, 8f-h, and 8j exhibited good activities. The 2-(methoxymethyl)morpholino derivative, 8h, showed the most potent activity in vivo. The therapeutic effects of 8h on systemic infection against S. aureus IID 803 were over 10-fold more potent than that of ofloxacin. Compound 8h, which showed superior oral bioavailability, has a chiral center. The enantiomers of 8h were synthesized, and the in vitro and in vivo antibacterial activities were evaluated. Both enantiomers, (S)-8h and (R)-8h, and the racemic compound 8 exhibited similar activities in vitro and in vivo. Compounds 8b and 8f-h also showed good levels of antibacterial activity against MRSA strains. The morpholino derivatives with unique tetracyclic structures are characterized by strong antibacterial activities against MRSA strains.

4-Quinolones↗

PubMed2001

National and regional assessment of the antibacterial soap market: a step toward determining the impact of prevalent antibacterial soaps.

BACKGROUND: Consumer antibacterial soaps contain triclosan or triclocarban. No scientific data have been published to suggest that the use of antibacterial agents in household products prevents infection, and triclosan resistance mechanisms have recently been identified. Little data are available regarding the prevalence of antibacterial agents contained in consumer soaps. METHODS: In a physician-performed survey of 23 stores in 10 states from December 1999 to April 2000, investigators determined the number of national brand liquid and bar soaps and percent of each containing antibacterial agents sold at national chain, regional grocery, and Internet stores. RESULTS: Antibacterial agents were present in 76% of liquid soaps and 29% of bar soaps available nationally. There were no differences found between national, regional, and Internet stores. CONCLUSION: Overall, 45% of surveyed soaps contain antibacterial agents. With limited documented benefits and experimental laboratory evidence suggesting possible adverse effects on the emergence of antimicrobial resistance, consumer antibacterial use of this magnitude should be questioned.

Anti-Infective Agents↗

PubMed2003

[Comparison of the antibacterial activity on oral pathogens among six types of nano-silver base inorganic antibacterial agents].

OBJECTIVE: To Compare the antibacterial activity on oral pathogens among six types of nano-silver base inorganic antibacterial agents. METHODS: The oral pathogens selected were Streptococcus mutans(ATCC6715),Lactobacillus (ATCC4356),Actinomyces viscosus (ATCC19246), Candida Albicans (ATCC76615), Staphylococcus aureus (ATCC25923), Escherichia coli (ATCCC25922). Minimal bactericidal concentration (MBC) was determined by Liquid dilution method. RESULTS: Nano-silver base inorganic antibacterial agents had fine bactericidal activity against oral pathogens. The general antibacterial activity of six types were nearly equal. CONCLUSION: It is possible that nano-silver base inorganic antibacterial agents can be used in dental antibacterial materials.

Anti-Bacterial Agents↗

PubMed2005

[Antibacterial spectrum of antibacterial peptides from Musca domestica larvae and synergic interaction between the peptides and antibiotics].

In vitro antibacterial activities of three antibacterial peptides, alone and in combination with the antibiotics were measured by MIC and antibacterial spectrum. Synergy was observed when the peptides were combined with penicillin, streptomycin by FIC. The results show that antibacterial peptides have stronger inhibition of pathogenic bacterium, and antibacterial spectrum are very different. The interaction in antibacterial peptides, antibiotics and bacterium is extraordinary complex, except synergic action, there are antagonism and indifference.

Animals↗

PubMed1983

[The antibacterial activity of new cephem antibiotics against clinical isolates. A comparison of the antibacterial activity of cefotaxime with 6 other antibiotics].

During the period from May through July 1981, a comparative study was carried out on the antibacterial activities of cefotaxime (CTX) and ceftizoxime (CZX), cefoperazone (CPZ), latamoxef (LMOX), cefotiam (CTM), cefmetazole (CMZ) and cefazolin (CEZ). CTX and these other cephem antibiotics were tested against fresh clinical isolates which had been obtained from clinical materials by the laboratories of 14 participating medical institutions. 1. The clinical isolates were obtained from various clinical materials in the following decreasing order: urine, sputum and pus/discharge; 85.7% of the isolates came from these materials. 2. Concerning the sources of each species of clinical isolates, it was found that P. aeruginosa was isolated from the greatest number -9- of different clinical materials. This was followed by E. coli and E. cloacae, each isolated from 8 different clinical materials, and C. freundii and E. aerogenes, each found in 7 different clinical materials. 3. In relation to S. pyogenes, S. agalactiae and S. pneumoniae, CTX showed the best antibacterial activity; the second most potent antibiotic was CZX. CMZ and LMOX were found to show relatively high MIC values for those species. Against S. aureus, CEZ showed the best antibacterial activity, but 3 resistant strains had MICs of greater than 100 micrograms/ml. 4. With regard to Gram-negative bacteria, CTX and CZX showed the best antibacterial activities for all of the species, except for P. aeruginosa. These were followed, in order, by LMOX and CPZ. Compared with these 4 antibiotics, CTM, CMZ and CEZ were found to have inferior antibacterial activities against these bacteria. In relation to P. aeruginosa, the peak of the MIC distribution for CPZ was 6.25 micrograms/ml, and this was the best antibacterial activity detected with the various antibiotics tested. This was followed by CTX (25 micrograms/ml) LMOX (25 micrograms/ml) and CZX (50 micrograms/ml). CTM had an MIC of 100 micrograms/ml for 1 strain, and MICs of greater than 100 micrograms/ml for all of the other strains of P. aeruginosa, indicating them to be resistant to this antibiotic. All of the strains were resistant to CMZ and CEZ, showing MICs of greater than 100 micrograms/ml. 5. For each of the tested antibiotics, no correlation was found between the MIC and the serogroup for either P. aeruginosa or S. marcescens.

Bacteria↗

PubMed2003

Identification of a potent antibacterial factor isolated from bronchoalveolar lavage fluid: guanidine, N-[3-[(aminoiminomethyl)amino]propyl]-N-dodecyl-, a potential source of error in the analysis of antibacterial agents.

The widespread use of antibiotics in modern society has encouraged the search for new antibacterial compounds. In this laboratory investigations are being made to identify and characterise novel antibacterial peptides. With this in mind, the antibacterial properties of human bronchoalveolar lavage (BAL) fluid from sarcoidosis patients is being investigated. In this communication we report on the identification and characterisation of a highly active non-peptide antibacterial compound isolated from BAL fluid. The structure of this active compound was elucidated by high-resolution accurate mass and tandem mass spectrometry to be guanidine, N-[3-[(aminoiminomethyl)amino]propyl]-N-dodecyl-. This compound does not appear to be endogenous, and its presence in BAL fluid extracts presents a potential source of error in analysis of antibacterial agents. The biological effects of guanidine, N-[3-[(aminoiminomethyl)amino]propyl]-N-dodecyl- have not previously been described in the literature.

Anti-Bacterial Agents↗

PubMed1991

Antibacterial effects of different snake venoms: purification and characterization of antibacterial proteins from Pseudechis australis (Australian king brown or mulga snake) venom.

Venoms from 30 different snake species were tested in a disc diffusion assay for antibacterial effects against gram-positive and gram-negative bacteria. A number of venoms gave a zone of inhibition against both groups of bacteria, including Aeromonas hydrophila, an important pathogen of reptiles and amphibians. Two antibacterial components from the venom of an Australian elapid, Pseudechis australis (Australian king brown or mulga snake) were purified to homogeneity. The proteins, designated LAO1 and LAO2, had potent antibacterial properties associated with L-amino acid oxidase activity. Both had native and subunit mol. wts of 142,000 and 56,000, respectively. Antibacterial activity correlated with enzymatic activity and was eliminated with catalase. LAO1 and LAO2 had 244 and 113 units of L-amino acid oxidase activity/mg protein, respectively. Compared to tetracycline, a drug of choice for Aeromonas infections in humans, reptiles and amphibians, the in vitro antibacterial effects of LAO1 and LAO2 were respectively 70 and 17.5 times more effective (on a molar basis).

Aeromonas hydrophila↗

PubMed2005

Antibacterial properties of Ag nanoparticle loaded multilayers and formation of magnetically directed antibacterial microparticles.

Antibacterial coatings based on hydrogen-bonded multilayers containing in situ synthesized Ag nanoparticles were created on planar surfaces and on magnetic colloidal particles. We report the antibacterial properties of these coatings, determined using a disk-diffusion (Kirby-Bauer) test, as a function of the film thickness and the concentration of Ag nanoparticles in the hydrogen-bonded multilayers. The zone of inhibition (ZoI) determined by the disk-diffusion test increases as the thickness of the multilayer film is increased. Results obtained for the values of the ZoI as a function of film thickness can be described adequately with a simple diffusion model (i.e., the square of the zone of inhibition (ZoI) depended linearly on the logarithm of the thickness of the silver-loaded films). This observation suggests that, in order to incrementally increase the ZoI, an exponentially increasing amount of Ag is required within the multilayers. In general, there was no statistically significant correlation between the zone of inhibition and the number of Ag loading and reduction cycles. The duration of sustained release of antibacterial Ag ions from these coatings, however, could be prolonged by increasing the total supply of zerovalent silver in the films via multiple loading and reduction cycles. These results indicate that the release of silver is controlled by an oxidation mechanism at the surface of the nanoparticles and that repeated loading and reduction of silver leads preferentially to growth of the existing silver nanoparticles in the film as opposed to nucleation of new Ag nanoparticles. We also show that magnetic microspheres coated with silver nanoparticle loaded hydrogen-bonded multilayer thin films can be used to deliver antibacterial agents to specific locations. The minimum inhibitory concentration (MIC) of nanocomposite coated microspheres was determined by the agar dilution technique: antibacterial magnetic microspheres with higher concentrations of Ag nanoparticles exhibited lower MIC values.

Acrylic Resins↗

PubMedDate not supplied

Synthesis and antibacterial properties of peptidyl derivatives and cyclopeptides structurally based upon the inhibitory centre of human cystatin C. Dissociation of antiproteolytic and antibacterial effects.

Cysteine protease-inhibiting proteins of the cystatin superfamily can inhibit the replication of certain viruses and bacteria. The inhibitory centre of human cystatin C, the most widely distributed human cystatin, comprises three peptide segments. The present work describes the synthesis and antibacterial activity of 27 new peptidyl derivatives or cyclopeptides based upon the aminoterminal segment Arg8-Leu9-Val10-Gly11. Fourteen of the new compounds displayed antibacterial activity against from 1 up to 9 of 17 clinically important bacterial species tested. Antiproteolytic activity of a compound was usually not required for its antibacterial capacity. Peptidyl diazomethanes generally had a very narrow antibacterial spectrum, inhibiting only Streptococcus pyogenes, whereas cyclopeptides and peptidyl derivatives of the general structure X-Arg-Leu-NH-CH(iPr)-CH2-NH-Y had a much wider spectrum. The most potent of these substances displayed approximately equal minimal inhibitory and bactericidal concentrations of about 20 microg/ml for both Staphylococcus aureus and S. pyogenes and were devoid of antiproteolytic activity. Several of the new substances could protect mice against lethal intraperitoneal challenge with S. pyogenes. Though their target remains to be disclosed, the group of substances here reported might be promising for the development of antibacterial drugs and the discovery of novel principles of action.

Anti-Bacterial Agents↗

PubMed1998

Characterization of antibacterial COOH-terminal proenkephalin-A-derived peptides (PEAP) in infectious fluids. Importance of enkelytin, the antibacterial PEAP209-237 secreted by stimulated chromaffin cells.

Proenkephalin-A (PEA) and its derived peptides (PEAP) have been described in neural, neuroendocrine tissues and immune cells. The processing of PEA has been extensively studied in the adrenal medulla chromaffin cell showing that maturation starts with the removal of the carboxyl-terminal PEAP209-239. In 1995, our laboratory has shown that antibacterial activity is present within the intragranular chromaffin granule matrix and in the extracellular medium following exocytosis. More recently, we have identified an intragranular peptide, named enkelytin, corresponding to the bisphosphorylated PEAP209-237, that inhibits the growth of Micrococcus luteus (Goumon, Y., Strub, J. M., Moniatte, M., Nullans, G., Poteur, L., Hubert, P., Van Dorsselaer, A., Aunis, D., and Metz-Boutigue, M. H. (1996) Eur. J. Biochem. 235, 516-525). As a continuation of this previous study, in order to characterize the biological function of antibacterial PEAP, we have here examined whether this COOH-terminal fragment is released from stimulated chromaffin cells and whether it could be detected in wound fluids and in polymorphonuclear secretions following cell stimulation. The antibacterial spectrum shows that enkelytin is active against several Gram-positive bacteria including Staphylococcus aureus, but it is unable to inhibit the Gram-negative bacteria growth. In order to relate the antibacterial activity of enkelytin with structural features, various synthetic enkelytin-derived peptides were tested. We also propose a computer model of synthetic PEAP209-237 deduced from 1H NMR analysis, in order to relate the antibacterial activity of enkelytin with the three-dimensional structure. Finally, we report the high phylogenetic conservation of the COOH-terminal PEAP, which implies some important biological function and we discuss the putative importance of enkelytin in the defensive processes.

Adrenal Glands↗

PubMed1996

Studies on quinolone antibacterials. V. Synthesis and antibacterial activity of chiral 5-amino-7-(4-substituted-3-amino-1-pyrrolidinyl)-6- fluoro-1,4-dihydro-8-methyl-4-oxoquinoline-3-carboxylic acids and derivatives.

We previously demonstrated that 5-amino-7-(3-amino-1-pyrrolidinyl) -1-cyclopropyl-1,4-dihydro-8-methyl-4-oxoquinoline-3-carboxylic acid (7) has strong in vitro antibacterial activity even against quinolone-resistant bacteria. We examined optimization of the 3-aminopyrrolidine moiety of 7 by introduction of C-alkyl (Me, Et, Pr, di-Me, cyclopropyl) and N-alkyl groups (Me, di-Me). C-Alkylation at the 4-position of the 3-aminopyrrolidine moiety enhanced in vitro and in vivo antibacterial activity. (S)-5-Amino-7-(7-amino-5-azaspiro[2.4]hept-5-yl)-1-cyclopropyl-pyr rolidinyl) -1-cyclopropyl-6-fluoro-1,4-dihydro-8-methyl-4-oxoquinoline-3-carboxylic acid (15b) showed strong antibacterial activity (in vitro antibacterial activity including quinolone-resistant bacteria is 4 times more potent than that of ciprofloxacin (CPFX) (1); in vivo antibacterial activity is 1.5 to 20 times more potent than that of CPFX (1)) and reduced quinolone toxicity (free from both phototoxicity at a dosage of 30 mg/kg in guinea pigs (i.v.) and convulsion when coadministered with 4-biphenylacetic acid at a dosage of 20 micrograms in rats (i.c.v.)). Their selectivity between DNA topoisomerase II (derived from eukaryotic cells) and DNA gyrase (derived from bacterial cells) was about 3000-fold.

Animals↗

PubMed1980

Effect of nosiheptide as a feed additive in chicks on the quantity, duration, prevalence of excretion, and resistance to antibacterial agents of Salmonella typhimurium; on the proportion of Escherichia coli and other coliforms resistant to antibacterial agents; and on their degree and spectrum of resistance.

In the first experiment two groups (B and D) each of ten, 15-day-old chicks were fed for 33 days a diet supplemented with nosiheptide (20 g/t) and 2 groups (A and C) of 10 each a diet without medication. Groups A and B were inoculated with Salmonella typhimurium, var. copenhagen (variant resistant to nalidixic acid of the strain DVR 101) 5 days after treatment was started. At intervals of 2, 4, 6, 8, 10, 12, 14, 21, and 28 days postinoculation the following data were collected: the number of salmonella excreted per gram of feces, their duration and prevalence of excretion, and the proportion of salmonella resistant to 9 antibacterial agents commonly used in human and veterinary medicine, as well as their degree and spectrum of resistance. In the second experiment two groups of 10 chicks each were fed either a basal diet (control group) or a diet supplemented with nosiheptide at 20 g/t (treated group). Immediately before and at the end of treatment, the proportions of fecal coliforms, particularly E. coli, which were resistant to 11 commonly used antibacterial agents, and their degree and spectrum of resistance were determined in the 2 groups of chicks. All the strains isolated before treatment started were E. coli sensitive to the 11 antibacterial agents. The strains isolated at the end of treatment were coliforms otherthan E. coli (40% in the control group, 32% in the treated group) and E. coli (60 and 68%, respectively). Coliforms other than E. coli were, as is usual, resistant to ampicillin and sensitive to the other antibacterial agents. The E. coli strains were either sensitive to all the antibacterial agents or resistant to tetracycline and furazolidone (51.8% in the control group, 34.1% in the treated group), or resistant to furazolidone alone (3.7% in the control group, 5.8% in the treated group). In both experiments these determinations showed no appreciable differences between treated and untreated chicks.

Animal Feed↗