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PubMed1998

Anaphylaxis to topical bacitracin zinc ointment.

This report describes a case of systemic anaphylaxis to bacitracin zinc ointment in a 24-year-old man who was injured in a motorcycle accident. Extensive abrasions on the patient's extremities were cleaned with Shurclens before application of viscous Xylocaine and bacitracin zinc ointment. Five minutes later, the patient exhibited symptoms of severe anaphylaxis and required the administration of epinephrine, antihistamines, intravenous fluids, and corticosteroids. Two weeks later, he underwent prick/puncture skin testing to Shurclens and bacitracin zinc ointment as well as prick/puncture, intracutaneous, and subcutaneous challenge with Xylocaine. Only the result of the prick test to bacitracin zinc ointment was positive. Although bacitracin is considered to be a safe topical antibiotic, physicians should be aware of the potential not only for delayed hypersensitivity but also for acute IgE-mediated allergic reactions and life-threatening anaphylaxis.

Administration, Cutaneous↗
PubMed1994

Competitive enzyme-linked immunosorbent assay for the determination of zinc bacitracin in animal feedingstuffs.

Traditionally, bioassay has been the chosen technique for the determination of bacitracin compounds in animal feedingstuffs. However, detection and determination of this antibiotic have given problems when it is present at low levels. A competitive enzyme-linked immunosorbent assay (ELISA) by which it is possible to detect both bacitracin and zinc bacitracin at levels as low as 1 mg kg-1 in animal feeds is described. The ELISA technique has been used in this laboratory to monitor samples from a drug stability storage trial for the presence of zinc bacitracin. In addition, individual polypeptide components of zinc bacitracin have been separated by high-performance liquid chromatography. Fractions were collected and tested by the ELISA technique to assess the response between individual components and the primary antibody. The response was compared with known microbiological activity.

Animal Feed↗
PubMed2003

The BceRS two-component regulatory system induces expression of the bacitracin transporter, BceAB, in Bacillus subtilis.

BceA and bceB encode a nucleotide-binding domain (NBD) and membrane-spanning domain (MSD) subunit, respectively, of an ATP-binding cassette (ABC) transporter in Bacillus subtilis. Disruption of these genes resulted in hypersensitivity to bacitracin, a peptide antibiotic that is non-ribosomally synthesized in some strains of Bacillus. Northern hybridization analyses showed that expression of the bceAB operon is induced by bacitracin present in the growth medium. The bceRS genes encoding a two-component regulatory system are located immediately upstream of bceAB. Deletion analyses of the bceAB promoter together with DNase I footprinting experiments revealed that a sensor kinase, BceS, responds to extracellular bacitracin either directly or indirectly and transmits a signal to a cognate response regulator, BceR. The regulator binds directly to the upstream region of the bceAB promoter and upregulates the expression of bceAB genes. The bcrC gene product is additionally involved in bacitracin resistance. The expression of bcrC is dependent on the ECF sigma factors, sigmaM and sigmaX, but not on the BceRS two-component system. In view of these results, possible roles of BceA, BceB and BcrC in bacitracin resistance of B. subtilis 168 are discussed.

ATP-Binding Cassette Transporters↗
PubMed1971

Mechanism of action of bacitracin: complexation with metal ion and C 55 -isoprenyl pyrophosphate.

The inhibition by bacitracin of the enzymatic dephosphorylation of C(55)-isoprenyl pyrophosphate is abolished by the addition of chelating agents. If, however, the chelating agent is added after a preincubation of bacitracin with a divalent cation and the lipid substrate, then its addition has little effect, indicating that bacitracin, metal ion, and C(55)-isoprenyl pyrophosphate form a complex. Various divalent cations can participate in complex formation, but monovalent cations are ineffective. A direct demonstration of the formation of a complex between the C(55)-isoprenyl pyrophosphate and bacitracin in the presence of metal ions was obtained. Molecular models that show one possible conformation for a complex between bacitracin and the C(55)-isoprenyl pyrophosphate, in which the metal ion acts as a bridge between the two compounds, are presented.

Bacitracin↗
PubMed2001

Engineered biosynthesis of the peptide antibiotic bacitracin in the surrogate host Bacillus subtilis.

Nonribosomal peptides are processed on multifunctional enzymes called nonribosomal peptide synthetases (NRPSs), whose modular multidomain arrangement allowed the rational design of new peptide products. However, the lack of natural competence and efficient transformation methods for most of nonribosomal peptide producer strains prevented the in vivo manipulation of these biosynthetic gene clusters. In this study, we present methods for the construction of a genetically engineered Bacillus subtilis surrogate host for the integration and heterologous expression of foreign NRPS genes. In the B. subtilis surrogate host, we deleted the resident 26-kilobase srfA gene cluster encoding the surfactin synthetases and subsequently used the same chromosomal location for integration of the entire 49-kilobase bacitracin biosynthetic gene cluster from Bacillus licheniformis by a stepwise homologous recombination method. Synthesis of the branched cyclic peptide antibiotic bacitracin in the engineered B. subtilis strain was achieved at high level, indicating a functional production and proper posttranslational modification of the bacitracin synthetases BacABC, as well as the expression of the associated bacitracin self-resistance genes. This engineered and genetically amenable B. subtilis strain will facilitate the rational design of new bacitracin derivatives.

Anti-Bacterial Agents↗
PubMed2006

Bacitracin reveals a role for multiple thiol isomerases in platelet function.

The platelet-specific integrin alphaIIb beta3 has endogenous thiol isomerase activity associated with the CXXC motifs within the beta subunit. Using a highly purified form of bacitracin, a thiol isomerase inhibitor, we now provide further evidence of the functional significance of this enzymatic activity in integrin activation. In addition, we demonstrate a role for multiple thiol isomerases in platelet function. This bacitracin prevented platelet aggregation to thrombin and collagen, and directly inhibited alphaIIb beta3 activation, as detected by PAC-1 binding. In parallel, bacitracin inhibited the endogenous thiol isomerase activity of purified alphaIIb beta3 with a 50% inhibitory concentration of 15.5 micromol/l. In order to determine whether the effects of bacitracin are solely mediated by inhibition of integrin enzymatic activity, we examined integrin-independent indices of platelet activation. We found bacitracin inhibited both platelet secretion (CD62P and CD63) and thromboxane (TxA2) production, with complete inhibition at different concentrations. Thus, we demonstrated a role for multiple thiol isomerases in platelet function. Taken together, these studies support a role for the endogenous integrin thiol isomerase activity in activation of alphaIIb beta3 and highlight the novel regulation of platelet function by other, as yet undefined thiol isomerases.

Bacitracin↗
PubMed1994

Isolation and characterization of Tn917-generated bacitracin deficient mutants of Bacillus licheniformis.

Two Tn917-generated bacitracin deficient mutants of Bacillus licheniformis were isolated. Southern blot analysis of chromosomal DNA extracted from both insertional mutants showed that Tn917 inserted in the vicinity of the gene coding for the enzyme BA2 of the bacitracin synthetase enzyme complex. Measurements of bacitracin synthetase activity in cell-free extracts and positive hybridization signals in the vicinity of the BA2 gene indicate that in both bacitracin deficient mutants Tn917 could be inserted in the BA1 gene or in segments involved in regulation. Thus, it could be possible that the genes for bacitracin synthetase are clustered in the B. licheniformis genome.

Bacillus↗
PubMed1976

Possible functions of peptide antibiotics during growth of producer organisms: bacitracin and metal (II) ion transport.

The inhibitory effect of bacitracin upon growth of the producer strain Bacillus licheniformis ATCC 10716 was dependent upon the presence of several different metal (II) ions, particularly Mn (II), Co (II), or Zn (II) ions. This supports our previous suggestion that the normal function of bacitracin during growth of the producer organism may be to promote the uptake of several divalent metal ions. Due to the striking similarity between the antimicrobial effect of bacitracin towards susceptible organisms and the effect of bacitracin towards the producer organisms B. licheniformis ATCC 10716, the possibility that the antimicrobial effect of bacitracin may be an induction of uptake of toxic amounts of metal ions is discussed. The possibility that peptide antibiotics may normally participate in ion transport during growth of producer organisms is also discussed.

Bacillus↗
PubMed1983

Synergism of the antimicrobial agents miconazole, bacitracin and polymyxin B.

The antibacterial activity of a combination of miconazole with bacitracin against Staphylococcus epidermidis or Staphylococcus aureus, was greater than the sum of the effects observed with the two drugs independently. Since no uptake changes were observed, this synergism may originate from a combined effect of miconazole and bacitracin on the biosynthesis of the carrier lipid, undecaprenyl-phosphate, resulting in an impairment of cell wall integrity. The synergism between these drugs and polymyxin B may be due to an increased accessibility of the cell membrane to polymyxin B. Miconazole and bacitracin, alone or in combination, are completely inactive against Escherichia coli. Since polymyxin B disturbs the permeability barrier and stimulates the uptake of miconazole, the synergism of polymyxin B, miconazole and bacitracin may originate from the ability of miconazole and bacitracin to penetrate the bacterial membranes in the presence of polymyxin B.

Bacitracin↗
PubMed1984

Umbilical cord care. A study of bacitracin ointment vs. triple dye.

Umbilical cord colonization rates were examined over a 4-year period following topical application of bacitracin (1978-1980) or triple dye (1980-1982). A total of 2402 cords were cultured: 1229 following bacitracin cord care and 1173 after triple dye application. Cords treated with bacitracin had significantly higher colonization rates when compared to triple dye prophylaxis. Bacterial colonization with Staphylococcus epidermidis and group B beta-hemolytic streptococcus was found only after bacitracin prophylaxis. Our data support the use of triple dye for routine cord care and suggest that bacitracin application may increase the rate of group B streptococcal colonization.

Acridines↗
PubMed1983

Effect of bacitracin and polyamines on follicle-stimulating hormone binding to membrane-bound and detergent-solubilized bovine calf testis receptor.

We have examined the effects of bacitracin and several polyamines on the interaction of 125I-human FSH (125I-hFSH) with membrane-bound receptors (MR) or detergent-solubilized receptors (DSR) derived from bovine calf testes. Binding of 125I-hFSH to either calf testis MR or DSR was inhibited by bacitracin in a dose-related manner. Inhibition of 125I-hFSH binding to either MR or DSR was due to a decrease in the apparent affinity constant (Ka) of receptor for FSH. FSH binding inhibition by bacitracin was significantly greater with the MR (ED50 = 5.9 mM) than with the DSR (ED50 = 25 mM). Bacitracin was a more potent inhibitor of binding than the polyamines at equimolar concentrations in both MR and DSR systems. The inhibitor potency of the polyamines when using DSR was related to chain length and the number of amino groups present (spermine greater than spermidine greater than putrescine). Although it was not possible to ascertain the mechanism of binding inhibition, our results demonstrate a direct effect of bacitracin and polyamines on the interaction of FSH with testis receptors.

Animals↗
PubMed1985

Evidence that bacitracin alters intracellular insulin metabolism in isolated rat hepatocytes.

The effect of bacitracin on intracellular insulin degradation was investigated using an isolated rat hepatocyte preparation in which essentially all insulin degradation was due to cell-mediated processes. Bacitracin produced a concentration-dependent decrease in the degradation of insulin to products soluble in trichloroacetic acid, with a half-maximal effect at approximately 0.5 mM. These results were confirmed by analysis of extracted cell-bound radioactivity by Sephadex G-50 molecular sieve chromatography. Radioactive material eluting in the position of intact insulin from the G-50 column was further analyzed by reversed-phase, high-performance liquid chromatography. In addition to intact insulin, two peaks of radioactive material less hydrophobic than insulin were evident. Incubation of cells in the presence of 0.5 mM bacitracin significantly (P less than 0.05) altered the distribution of radioactivity in these two peaks. These results indicate that bacitracin significantly affects hepatocyte insulin metabolism and suggest that the continued use of bacitracin in studies of hepatocyte-insulin interaction should be avoided.

Animals↗
PubMed1988

Kinetics of endotoxin release by gram-negative bacteria in the intestinal tract of mice during oral administration of bacitracin and during in vitro growth.

The release of endotoxin by gram-negative bacteria was studied during bacitracin-induced intestinal colonization in C3H/Law mice and during in vitro growth. The "free" endotoxin concentration was determined by the Limulus amebocyte lysate test in faecal and in culture supernatants, respectively. After oral administration of bacitracin for 2 days a significant (p less than 0.001) increase of the faecal concentration of gram-negative bacteria of 3-4 logs accompanied a significant (p less than 0.001) increase of the faecal endotoxin concentration from 10(1.8 +/- 0.2) to 10(3.3 +/- 0.2) micrograms endotoxin/g faeces. In vitro, however, an increase of the concentration of gram-negative bacteria of 3-4 logs resulted in a 3-4 log increase of the concentration of endotoxin during the exponential and early stationary growth phase. The faecal endotoxin level after 8 days of bacitracin treatment dropped to a value not significantly different from the initial value, regardless of a high faecal level of gram-negative bacteria. Endotoxin determination by the Limulus amebocyte lysate test appeared to be unaffected by the amount of bacitracin present in faecal preparations after oral administration of this antibiotic. In addition, the in vitro release of endotoxin was not influenced by bacitracin. From these results we conclude, that "free" endotoxin is a product of extensive proliferation of gram-negative bacteria. Therefore, the intestinal endotoxin level does not necessarily correlate with the level of gram-negative bacteria, but corresponds with the proliferative activity of these bacteria.

Animals↗
PubMed1977

The control and prevention of necrotic enteritis in broilers with zinc bacitracin.

The effectiveness of zinc bacitracin in controlling andpreventing necrotic enteritis was tested by growing broilers in a facility where necrotic enteritis outbreaks had previously occurred. Broiler-crossed chicks were fed a commercial-type broiler diet containing 0 mg./kg., 33 mg./kg., or 55 mg./kg. of zinc bacitracin in the diet. Each treatment was replicated six times. Mortality, weight gain, feed conversion, and pigmentation were measured. The control group had 7.4% mortality due to necrotic enteritis as determined by necropsy of each bird upon death. Zinc bacitracin at 10 grams per ton had two mortalities, or 0.4% mortality due to necrotic enteritis. No mortality due to necrotic enteritis occurred with the higher levels of zinc bacitracin. The addition of zinc bacitracin significantly improved (P less than 0.01) the parameters of weight gain, feed conversion, and pigmentation.

Animals↗
PubMed1983

Effects of diet and bacitracin on growth, feed efficiency, and populations of Clostridium perfringens in the intestine of broiler chicks.

Experiments were conducted to demonstrate the activity of bacitracin as a growth permittant for poultry and to further elucidate the mode of action of antimicrobial agents for that purpose. Supplementing a soybean protein and sucrose-based diet with 2.2, 11, and 55 ppm of bacitracin resulted in significant improvements in weight gain and feed efficiency of chicks fed the higher levels. In a second experiment, graded levels of bacitracin from 1.1 to 55 ppm were fed. A regression analysis of the index scores, the combined effects of both weight gain and feed efficiency, on the log of the significant dose levels of 5.5 to 27.5 ppm gave a linear response line with r = .996. Based on the equation, the ineffective level of the antibiotic was determined to be 4 ppm and the maximum effective level 31 ppm. Supplementing the soybean protein and sucrose-based diet with levels of 5.5, 16.5, and 55 ppm of bacitracin reduced the numbers of Clostridium perfringens organisms in ileal contents of chicks (all P less than .05). Chicks fed a level of 1.1 ppm, a level that did not give a growth response, had numbers of the organism present that were not significantly different from controls. Supplementing a soybean meal and corn-based diet with a level of 55 ppm of bacitracin did not significantly affect weight gain, feed efficiency, or numbers of C. perfringens in the ileum of chicks.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Effects of diet, bacitracin, and body weight restrictions on the intestine of broiler chicks.

Six experiments were conducted to evaluate the effects of diet, bacitracin, and body weight restrictions on the intestine of the broiler chick. Bacitracin, at levels of 11 and 55 ppm, significantly increased body weight, significantly reduced small intestine weight, but had no significant effect on liver weight of chicks fed a soybean protein and sucrose-based diet. The greatest effects were observed in the ileum where weight, moisture, length per unit of body weight, and dry matter per unit of length were all significantly reduced. The least effects were observed in the duodenum where weight and length per unit of body weight were significantly reduced and dry matter per unit of length was significantly increased. Intestinal weight, as a percent of body weight, was not significantly affected when body weight was suppressed with a high level of nicarbazin added to a practical diet, but it was significantly reduced when bacitracin was added to the semipurified diet and chicks were restricted in food intake to 70% of controls. A level of 55 ppm of bacitracin added to the practical diet had no significant effect on body weight, intestinal weight, or liver weight. As discussed, the observed changes in the intestine, due to bacitracin, are probably indirect and most likely reflect the action of the antibiotic on the intestinal microflora.

Animals↗
PubMed1990

The effect of zinc bacitracin and roxarsone on performance of broiler chickens when fed in combination with narasin.

Six trials were conducted at various locations to determine the response of broiler chickens to combinations of zinc bacitracin and roxarsone when fed in the presence of narasin. The addition of zinc bacitracin at 55 mg per kg significantly improved growth rate and feed utilization when data from all locations were combined. There was no effect of roxarsone fed at 50 mg per kg on BW or feed utilization, nor was there an interaction of roxarsone and zinc bacitracin on BW. There was a significant interaction of roxarsone and zinc bacitracin for feed utilization; addition of zinc bacitracin significantly improved feed utilization both in the presence and absence of roxarsone, but the improvement was greater in the absence of roxarsone.

Animal Feed↗
PubMed1953

The international standard for bacitracin.

In 1952, the Department of Biological Standards, National Institute for Medical Research, London, was authorized by the WHO Expert Committee on Biological Standardization to proceed with the establishment of an International Standard for Bacitracin. Thirty grams of bacitracin were obtained and it was decided to compare the proposed International Standard with the existing Working Standard for Bacitracin of the United States Food and Drug Administration.Six laboratories in five countries participated in the collaborative assay. A total of 52 assays was carried out, but the overall weighted mean potency was calculated from only the 48 biological assays, the 4 assays by the Hiscox method being excluded. The biological assays were done by the plate, the cylinder, or the disc method, using Streptococcus pyogenes, Staphylococcus aureus, Corynebacterium xerosis, or Micrococcus flavus.After analysing the results by standard statistical methods, the authors established the batch of bacitracin examined as the International Standard. The Standard contains 55 International Units of activity per mg, and the International Unit has therefore been defined as the activity contained in 0.0182 mg of the International Standard for Bacitracin.

Bacitracin↗