Bacitracin is a broad-spectrum antibiotics mainly produced by Bacillus, and is used as veterinary medicine in the fields of livestock and poultry breeding. Insufficient supply of precursor amino acids might be an important factor that hinders high-level microbial production of bacitracin. We investigated the effect of strengthening L-cysteine supply on bacitracin production by an industrial bacitracin producer, Bacillus licheniformis DW2. Overexpression of cysK encoding L-cysteine synthase led to a 9.17% increase of the bacitracin titer. Moreover, overexpression of cysE encoding L-serine acetyltransferase and cysP encoding thiosulfate/sulfate intracellular transporter increased the bacitracin titers by 7.23% and 8.52%, respectively. Moreover, overexpression of a putative cystine importer TcyP led to a 29.19% increase of intracellular L-cysteine, and bacitracin titer was increased by 7.79%. Subsequently, the strong promoter PbacA was used to replace the promoters of genes cysP, cysE and tcyP in strain DW2::ysK, respectively. The resulted strain CYS4 (DW2::cysK-PbacA-(cysP)-PbacA(cysE)- PbacA(tcyP) produced 910.02 U/mL bacitracin, which was 21.10% higher than that of the original strain DW2 (747.71 U/mL). Together with the experiments in 3 L fermenters, this research demonstrated that enhancing intracellular L-cysteine supply is an effective strategy to increase bacitracin production of B. licheniformis.
Amino Acids ; Bacillus licheniformis/genetics* ; Bacitracin ; Cysteine ; Metabolic Engineering

The purpose of this study is to survey the frequency of mutans streptococci species and biotypes isolated from dental plaque in Korean adolescents and adults and the relationship between species of mutans streptococci and DMFT index. The dental plaque samples were collected from the anterior and molar teeth of both of jaws in the 47 human subjects (aged 14 to 29.3 years, average age was 20.2 years). A dental examination was performed for DMFT with the WHO caries diagnostic criteria. The mutans streptococci were cultured selectively on mitis-salivarius bacitracin (MSB) agar plates. The bacterial colonies growing on the MSB plates were then identified with biochemical tests (for biotyping) as well as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dextranase gene (dex) (for the determination of species). The data showed that the prevalence of Streptococcus mutans, S. sobrinus, and S. downei were 93.6%, 12.8%, and 8.5%, respectively. The biotype I (87.4%) and biotype IV (19.1%) were the most frequently detected. The DMFT scores of adolescents and adults harboring both S. mutans and S. sobrinus were significantly higher than those for S. mutans alone (p < 0.05). Above results revealed that S. mutans and biotype I were frequently detected in Korean adolescents and adults. In addition, the results suggest that subjects having plaques compared of both S. mutans and S. sobrinus may be more susceptible to caries than those having S. mutans alone.
Adolescent* ; Adult* ; Agar ; Bacitracin ; Dental Plaque* ; Dextranase ; Humans ; Jaw ; Molar ; Prevalence ; Streptococcus mutans ; Tooth

BACKGROUND: Group A streptococci (GAS) are the most common cause of pharyngitis in children. The streptococci in throat cultures from healthy elementary school children in Jinju were compared with previous results. METHODS: Throat cultures were taken from 1,402 healthy school children in 2006. beta-hemolytic streptococci (BHS) were identified with a bacitracin disk (0.04 U) and latex agglutination test (Seroiden Strepto Kit, Eiken, Tokyo, Japan). RESULTS: Two-hundred sixteen (15.4%) and 149 (10.6%) cultures grew BHS and GAS, respectively. The isolation rate of GAS was significantly lower than in 2004 (16.0%) or 2002 (16.9%) (P<0.05). Among BHS, the prevalence of group A strains (69.0%) decreased significantly compared with 2004 (84.9%) and 2002 (83.8%) (P<0.05). None of the 1st-grade children yielded BHS or GAS. CONCLUSION: The isolation rates of BHS and GAS from healthy school children were lower in 2006 than in previous years. Natural immunization against the common serotypes or improvement in individual hygiene might have played roles in the reduction of isolations of GAS.
Bacitracin ; Child ; Humans ; Hygiene ; Immunization ; Latex Fixation Tests ; Pharyngitis ; Pharynx ; Prevalence ; Streptococcus pyogenes ; Tokyo

PURPOSE: A major concern of implanting urologists is infection, which occurs in 2% to 4.5% of cases. The present study was undertaken to investigate whether a hydrophilic coating which is designed to reduce bacterial adherence, applied to an inflatable penile prosthesis (IPP), would prolong the effect of antibiotics utilized intraoperatively. MATERIALS AND METHODS: The efficacy of antibiotics-soaked Bioflex(penile prosthetic substrate material) disc with and without hydrophilic coating was examined using an in-vivo rabbit model. A total of 320 Bioflex discs were used. 160 discs were coated with hydrophilic coating, and the remaining 160 disc, which were not coated, served as controls. All discs were soaked in an aqueous solution of gentamycin and bacitracin. Each group of 16 animals contained 64 discs. Two coated and 2 uncoated Bioflex discs were implanted subcutaneously in the dorsal region of each rabbit. The implanted antibiotic-soaked discs were extracted at 0, 1, 2, 3, and 5 days following implantation, and the zone of inhibition against S. epidermidis, S. aureus, E. coli, and P. aeruginosa in vitro was determined. RESULTS: A zone of inhibition for each of the microorganisms was present for all discs (coated and uncoated) at day 0. From day 1 to day 3, the coated discs demonstrated continued microbial inhibition against S. epidermidis compared to the uncoated discs, which did not. CONCLUSIONS: This study demonstrated that the use of a hydrophilic coating as a penile implant coating does not reduce the effectiveness of antibiotics utilized intraoperatively. Additionally, the coated discs demonstrated a sustained antibiotics activity against S. epidermidis for at least 3 days. This effect, along with the reduced adherence properties of the hydrophilic coating, may prevent the adhesion and colonization of S. epidermidis to penile implants and thereby reduce the chance of prosthetic infection.
Animals ; Anti-Bacterial Agents ; Bacitracin ; Colon ; Gentamicins ; Penile Prosthesis ; Polyvinyls* ; Prostheses and Implants

BACKGROUND: The carrier study of group A streptococci (GAS), the most common cause of bacterial pharyngitis, is important to understand the epidemiology of GAS in the region. The authors performed throat cultures from the children of four elementary schools in Jinju area to investigate current microbiological characteristics in this area. METHODS: Throat cultures were taken from 2,351 healthy elementary school children (male 1,311 and female 1,040) from October through December, 2004. Two schools are located in rural areas, while the other two schools are in Jinju city. Beta-hemolytic streptococci (BHS) were identified with bacitracin disk (0.04 U) and latex agglutination test (Seroiden Strepto Kit, Eiken). RESULTS: Four-hundred forty-three (18.8%) yielded BHS from 2,351 school children. Serogrouping revealed 84.9% of group A, 5.9% of group C, 4.7% of group B, 3.6% of group G, and 0.9% of non-group A, B, C, G in a decreasing order. Isolation rate of GAS was similar between girls and boys. Children of elementary schools in rural areas showed significantly higher isolation rates (18.6-21.7%) compared to those (12.5-12.7%) in urban areas. CONCLUSION: The isolation rate of BHS was 18.8% in Jinju area, 2004. Group A was 84.9% and group C was next common. Although the isolation rate of GAS was similar by age or sex, it showed a significant difference by the location of the schools.
Bacitracin ; Child* ; Epidemiology ; Female ; Gyeongsangnam-do* ; Humans ; Latex Fixation Tests ; Pharyngitis ; Pharynx*

Objective: To investigate the effect of three preoperative anti-infective regimens on the sterility of anterior-chamber aspirates (ACA) in eyes undergoing extracapsular cataract extraction (ECCE). Methods: Ninety eyes scheduled to undergo ECCE were randomly assigned to receive one of the following preoperative anti-infective regimens: Group 1 (Control) - no additional preoperative preparation; Group 2 (Eye drop) - neomycin/ polymixin B/gramicidin eye drops applied 3 times daily for 3 days prior to surgery; and Group 3 (Lid scrub) - neomycin/polymixin B/ bacitracin ointment lid scrub applied 3 times prior to surgery. ACAs were obtained from all eyes at the conclusion of surgery and cultured. The patients were followed up for 3 months after the surgery. Results: Positive cultures developed from ACAs in 5 (16.6 percent) of 30 eyes from Group 1, in 0 of 30 from Group 2, and in 3 (10 percent) of 30 from Group 3. No eye developed endophthalmitis. Compared with the control group, preoperative neomycin/polymixin B/gramicidin eye drops significantly reduced the ACA contamination rate (p= 0.03). Conclusion: Preoperative neomycin/polymixin B/bacitracin eyedrops can improve the sterility of the anterior chamber during ECCE.
Human ; CATARACT ; ANTI-INFECTIVE AGENTS ; ENDOPHTHALMITIS ; NEOMYCIN ; GRAMICIDIN ; BACITRACIN ; CATARACT EXTRACTION ; EYE DISEASES ;

The aim of this study was to compare the species and biotypes of mutans streptococci isolated from dental plaques sampled from the interfaces between the bracket and tooth surface and smooth tooth surfaces in orthodontic patients. Dental plaque was collected from the interfaces between brackets and teeth (test group), and from smooth tooth surfaces distant from brackets by more than 2 mm (control group). The dental plaque collected by a sterilized curette was transferred into a vial of 1 X PBS. The sample in the vial was vigorously vortexed for 1 min and plated on mitis-salivarius bacitracin (MSB) agar plate using cotton tips. The agar plates were incubated at 37 degrees C in a candle jar for 2 days, and again incubated for 1 more day at anambient temperature. Individual colonies were cultured in TH broth at 37 degrees C CO2 incubator. The PCR-RFLP based on dextranase gene was performed for the identification of mutans streptococci at the species-level. For biotyping of mutans streptococci, biochemical tests were performed. There was no significant difference of the species of mutans streptococci isolated from both test and control groups. However, the biotypes of the mutans streptococci isolated from test and control groups were different. These results may offer the basic data to verify the relationship between the mutans streptococci biotype and enamel decalcification or dental caries in orthodontic patients with fixed appliances.
Agar ; Bacitracin ; Dental Caries ; Dental Enamel ; Dental Plaque* ; Dextranase ; Humans ; Incubators ; Tooth*

Bacitracin is a broad-spectrum cyclic peptide antibiotic, and mainly produced by Bacillus. Energy metabolism plays as a critical role in high-level production of target metabolites. In this study, Bacillus licheniformis DW2, an industrial strain for bacitracin production, was served as the original strain. First, our results confirmed that elimination of cytochrome bd oxidase branch via deleting gene cydB benefited bacitracin synthesis. Bacitracin titer and ATP content were increased by 10.97% and 22.96%, compared with those of original strain, respectively. Then, strengthening cytochrome aa3 oxidase branch via overexpressing gene qoxA was conducive to bacitracin production. Bacitracin titer and ATP content were increased by 18.97% and 34.00%, respectively. In addition, strengthening ADP synthesis supply is also proven as an effective strategy to promote intracellular ATP accumulation, overexpression of adenosine kinase DcK and adenylate kinase AdK could all improve bacitracin titers, among which, dck overexpression strain showed the better performance, and bacitracin titer was increased by 16.78%. Based on the above individual methods, a method of combining the deletion of gene cydB and overexpression of genes qoxA, dck were used to enhance ATP content of cells to 39.54 nmol/L, increased by 49.32% compared to original strain, and bacitracin titer produced by the final strain DW2-CQD (DW2ΔcydB::qoxA::dck) was 954.25 U/mL, increased by 21.66%. The bacitracin titer produced per cell was 2.11 U/CFU, increased by 11.05%. Collectively, this study demonstrates that improving ATP content was an efficient strategy to improve bacitracin production, and a promising strain B. licheniformis DW2-CQD was attained for industrial production of bacitracin.
Bacillus licheniformis ; metabolism ; Bacitracin ; biosynthesis ; Energy Metabolism ; genetics ; Industrial Microbiology ; methods

Diarrhea is a common complication of antibiotics usage. The diarrhea ascribed to antibiotics usually consist of loose or watery stools, sometimes containing mucus but rarely grossly evident blood. Almost every antibiotics has been implicated, although cases related to the use of vancomycin or aminoglycosides are rare. Although the pathogenesis of antibiotics-associated diarrhea is not confirmed, recent studies have shown that a toxin of clostridium difficile is implicated as a cause of it. Diagnosis is made by detecting toxin in the stool or stool culture for C.difficile. Treatment is either directed at binding the toxin with anion exchange resins such as cholestyramine in mild case, or at eradicating the C.difficile organism with vancomycin, metronidazole or bacitracin for more severe cases. (continue...)
Aminoglycosides ; Anion Exchange Resins ; Anti-Bacterial Agents ; Bacitracin ; Cholestyramine Resin ; Clostridium difficile ; Clostridium* ; Diagnosis ; Diarrhea ; Enterocolitis, Pseudomembranous* ; Metronidazole ; Mucus ; Vancomycin

Our present knowledge of impetigo contagiosa extends from its first description as a separate clinical entity by Fox in I864, and the proof of its bacterial etiology by Radcliffe-Crocker in 1881. Both staphylococci and streptococci have been discovered from the lesions, but the relative preponderance of each varies greatly, and reports are contradictory. Seventy-eight patients with impetigo contagiosa were studied bacteriologically in order to ascertain the primary etiologic agent. Also, a susceptibility test (Bauer- Kirby method) was done on the isolated organisms with 7 antibiotics which are used frequently in the clinical field. Specimens obtained from the skin lesions were cultured and organisms were isolated. They were identified by various biochemical and serological tests. A DN ase test, a carbohydrate fermentation test, and a coagulase test were done for the isolated staphylococci. A bacitracin disc method and a precipitin test(Lancefield method) were done for the isolated B-hemolytic streptococci. The results were as follows: Fifty-six cases(71.8%) were infected by staphylococcus only. Twenty cases(25.6%) were infected by a mixture of staphylococcus and p-hemo- lytic streptococcus. Only 2 cases(2.6%) were infected by B-hemolytic streptococcus alone. All 76 strains of staphylococci were identified as coagulase positive staphylococci. Among the 22 strains of B-hemolytic streptococci, 15 strains were identified as group A and remaining 7 strains were identified as group B. Coagulnse negative sta,phylococcus was not found. In the susceptibility test to 7 antibiotics, staphylococci showed susceptibility to lincomycin, erythromycin, cloxacillin, and chloramphenicol, and resistance to tetra-cycline, penicillin, and ampicillin. Streptococci showed susc.ptibility to all of the above antibiotics except tetracycline. From the results of this experiment, it was concluded that the primary etiologic agent of impetigo contagiosa was coagulase positive staphylococcus and streptococcus for the most part can be considered as a secondarily infecting agent. Coagulase negative staphylococcus apparently is not implicated as an etiologic agent of impetigo contagiosa. The results of the antibiotic susceptibility tests would seem to indicate that the use of such antibiotics as tetracycline, penicillin, and ampicillin is not indicated in the treatment of impetigo contagiosa.
Ampicillin ; Anti-Bacterial Agents ; Bacitracin ; Chloramphenicol ; Cloxacillin ; Coagulase ; Erythromycin ; Fermentation ; Humans ; Impetigo ; Lincomycin ; Penicillins ; Serologic Tests ; Skin ; Staphylococcus ; Streptococcus ; Tetracycline